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/*!
    \page qmake-manual.html
    \title qmake Manual
    \startpage {index.html}{Qt Reference Documentation}
    \nextpage Overview

    \ingroup qttools
    \keyword qmake

    The qmake tool helps simplify the build process for development projects
    across different platforms. It automates the generation of Makefiles so that
    only a few lines of information are needed to create each Makefile.
    You can use qmake for any software project, whether it is written with Qt or
    not.

    qmake generates a Makefile based on the information in a
    project file. Project files are created by the developer, and are usually
    simple, but more sophisticated project files can be created for complex
    projects.

    qmake contains additional features to support development
    with Qt, automatically including build rules for \l{moc.html}{moc}
    and \l{uic.html}{uic}.

    qmake can also generate projects for Microsoft Visual studio
    without requiring the developer to change the project file.

    \section1 Table of Contents

    \list
        \li \l{Overview}
        \li \l{Getting Started}
        \li \l{Creating Project Files}
        \li \l{Building Common Project Types}
        \li \l{Running qmake}
        \li \l{Platform Notes}
        \li \l{qmake Language}
        \li \l{Advanced Usage}
        \li \l{Using Precompiled Headers}
        \li \l{Configuring qmake}
        \li \l{Reference}
        \list
            \li \l{Variables}
            \li \l{Replace Functions}
            \list
                \li \l{Built-in Replace Functions}
           \endlist
           \li \l{Test Functions}
            \list
                \li \l{Built-in Test Functions}
                \li \l{Test Function Library}
            \endlist
        \endlist
    \endlist
*/

/*!
    \page qmake-overview.html
    \title Overview
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Manual
    \nextpage Getting Started

    The qmake tool provides you with a project-oriented system for managing the
    build process for applications, libraries, and other components.
    This approach gives you control over the source files used, and
    allows each of the steps in the process to be described concisely,
    typically within a single file. qmake expands
    the information in each project file to a Makefile that executes the necessary
    commands for compiling and linking.

    \section1 Describing a Project

    Projects are described by the contents of project (\c .pro) files. qmake
    uses the information within the files to generate Makefiles that contain
    all the commands that are needed to build each project.
    Project files typically contain a list of source and header files,
    general configuration information, and any application-specific details,
    such as a list of extra libraries to link against, or a list of extra
    include paths to use.

    Project files can contain a number of different elements, including
    comments, variable declarations, built-in functions, and some simple
    control structures. In most simple projects, it is only necessary
    to declare the source and header files that are used to build the
    project with some basic configuration options. For more information about
    how to create a simple project file, see \l{Getting Started}.

    You can create more sophisticated project files for complex projects. For an
    overview of project files, see \l{Creating Project Files}. For detailed
    information about the variables and functions that you can use in project
    files, see \l{Reference}.

    You can use application or library project templates to specify specialized
    configuration options to fine tune the build process. For more information,
    see \l{Building Common Project Types}.

    You can use the \l{external: Qt Creator Manual}{Qt Creator} new project
    wizard to create the project file. You choose the project template, and Qt
    Creator creates a project file with default values that enable you to build
    and run the project. You can modify the project file to suit your purposes.

    You can also use qmake to generate project files. For a full description of
    qmake command line options, see \l{Running qmake}.

    The basic configuration features of qmake can handle most cross-platform
    projects. However, it might be useful, or even necessary, to use some
    platform-specific variables. For more information, see \l{Platform Notes}.

    \section1 Building a Project

    For simple projects, you only need to run qmake in the top level directory
    of your project to generate a Makefile. You can then run your platform's
    \c make tool to build the project according to the Makefile.

    For more information about the environment variables that qmake uses when
    configuring the build process, see \l{Configuring qmake}.

    \section1 Using Third Party Libraries

    The guide to \l{Third Party Libraries} shows you how to use simple third
    party libraries in your Qt project.

    \section1 Precompiling Headers

    In large projects, it is possible to take advantage of precompiled
    header files to speed up the build process. For more information, see
    \l{Using Precompiled Headers}.
*/

/*!
    \page qmake-project-files.html
    \title Creating Project Files
    \contentspage {qmake Manual}{Contents}
    \previouspage Getting Started
    \nextpage Building Common Project Types

    Project files contain all the information required by qmake to build your
    application, library, or plugin. Generally, you use a series of declarations
    to specify the resources in the project, but support for simple programming
    constructs enables you to describe different build processes for different
    platforms and environments.

    \section1 Project File Elements

    The project file format used by qmake can be
    used to support both simple and fairly complex build systems.
    Simple project files use a straightforward declarative style,
    defining standard variables to indicate the source and header files
    that are used in the project. Complex projects may use control flow
    structures to fine-tune the build process.

    The following sections describe the different types of elements used
    in project files.

    \target ProjectFileElementsVariables
    \section2 Variables

    In a project file, variables are used to hold lists of strings. In the
    simplest projects, these variables inform qmake
    about the configuration options to use, or supply filenames and paths to
    use in the build process.

    qmake looks for certain variables in each
    project file, and it uses the contents of these to determine what it
    should write to a Makefile. For example, the lists of values in the
    \l{HEADERS} and \l{SOURCES} variables are used to tell qmake about header
    and source files in the same directory as the project file.

    Variables can also be used internally to store temporary lists of values,
    and existing lists of values can be overwritten or extended with new
    values.

    The following snippet illustrates how lists of values are assigned to
    variables:

    \snippet qmake/variables.pro 0

    The list of values in a variable is extended in the following way:

    \snippet qmake/variables.pro 1

    \note The first assignment only includes values that are specified on
    the same line as the \c HEADERS variable. The second assignment splits
    the values in the \c SOURCES variable across lines by using a backslash
    (\\).

    The \l{CONFIG} variable is another special variable that qmake uses when
    generating a Makefile. It is discussed in \l{General Configuration}.
    In the snippet above, \c console is added to the list of existing values
    contained in \c CONFIG.

    The following table lists some frequently used variables and describes their
    contents. For a full list of variables and their descriptions,
    see \l{Variables}.

    \table
    \header \li Variable \li Contents
    \row \li \l{CONFIG}  \li General project configuration options.
    \row \li \l{DESTDIR} \li The directory in which the executable or binary file will
                      be placed.
    \row \li \l{FORMS}   \li A list of UI files to be processed by the
                         \l{uic}{user interface compiler (uic)}.
    \row \li \l{HEADERS} \li A list of filenames of header (.h) files used when
                      building the project.
    \row \li \l{Variables#QT}{QT} \li A list of Qt modules used in the project.
    \row \li \l{RESOURCES} \li A list of resource (.qrc) files to be included in the
                      final project. See the \l{The Qt Resource System} for
                      more information about these files.
    \row \li \l{SOURCES}  \li A list of source code files to be used when building
                      the project.
    \row \li \l{TEMPLATE} \li The template to use for the project. This determines
                      whether the output of the build process will be an
                      application, a library, or a plugin.
    \endtable

    The contents of a variable can be read by prepending the variable name with
    \c $$. This can be used to assign the contents of one variable to another:

    \snippet qmake/dereferencing.pro 0

    The \c $$ operator is used extensively with built-in functions that operate
    on strings and lists of values. For more information, see
    \l{qmake Language}.

    \section3 Whitespace

    Usually, whitespace separates values in variable assignments. To specify
    values that contain spaces, you must enclose the values in double quotes:

    \snippet qmake/quoting.pro 0

    The quoted text is treated as a single item in the list of values held by
    the variable. A similar approach is used to deal with paths that contain
    spaces, particularly when defining the
    \l{INCLUDEPATH} and \l{LIBS} variables for the Windows platform:

    \snippet qmake/spaces.pro quoting include paths with spaces

    \section2 Comments

    You can add comments to project files. Comments begin with the \c
    # character and continue to the end of the same line. For example:

    \snippet qmake/comments.pro 0

    To include the \c # character in variable assignments, it is necessary
    to use the contents of the built-in \l{LITERAL_HASH} variable.

    \section2 Built-in Functions and Control Flow

    qmake provides a number of built-in functions to enable the contents of
    variables to be processed. The most commonly used function in simple
    project files is the \l{include(filename)}{include()} function which takes a
    filename as an
    argument. The contents of the given file are included in the project
    file at the place where the \c include function is used.
    The \c include function is most commonly used to include other project
    files:

    \snippet qmake/include.pro 0

    Support for conditional structures is made available via
    \l{Scopes}{scopes} that behave like \c if statements in programming languages:

    \snippet qmake/scopes.pro 0

    The assignments inside the braces are only made if the condition is
    true. In this case, the \c win32 \l{CONFIG} option must be set. This
    happens automatically on Windows. The opening brace must stand on the same
    line as the condition.

    More complex operations on variables that would usually require loops
    are provided by built-in functions such as \l{findfunction}{find()},
    \l{unique}{unique()}, and \l{countfunction}{count()}. These functions, and
    many others are provided to manipulate
    strings and paths, support user input, and call external tools. For more
    information about using the functions, see \l{qmake Language}. For lists
    of all functions and their descriptions, see \l{Replace Functions} and
    \l{Test Functions}.

    \section1 Project Templates

    The \l{TEMPLATE} variable is used to define the type of project that will
    be built. If this is not declared in the project file,
    qmake assumes that an application should be
    built, and will generate an appropriate Makefile (or equivalent file)
    for the purpose.

    The following table summarizes the types of projects available and describes
    the files that qmake will generate for each of them:

    \table
    \header \li Template      \li qmake Output
    \row    \li app (default) \li Makefile to build an application.
    \row    \li lib           \li Makefile to build a library.
    \row    \li subdirs       \li Makefile containing rules for the
    subdirectories specified using the \l{SUBDIRS}
    variable. Each subdirectory must contain its own project file.
    \row    \li vcapp         \li Visual Studio Project file to build
                             an application.
    \row    \li vclib         \li Visual Studio Project file to build a library.
    \row    \li vcsubdirs     \li Visual Studio Solution file to build
                              projects in sub-directories.
    \endtable

    See \l{Building Common Project Types} for advice on writing project files for
    projects that use the \c app and \c lib templates.

    When the \c subdirs template is used, qmake
    generates a Makefile to examine each specified subdirectory,
    process any project file it finds there, and run the platform's
    \c make tool on the newly-created Makefile.
    The \c SUBDIRS variable is used to
    contain a list of all the subdirectories to be processed.

    \target GeneralConfiguration
    \section1 General Configuration

    The \l{CONFIG} variable specifies the options and features that the project
    should be configured with.

    The project can be built in \e release mode or \e debug mode, or both.
    If debug and release are both specified, the last one takes effect. If you
    specify the \c debug_and_release option to build both the debug and release
    versions of a project, the Makefile that qmake generates includes a rule
    that builds both versions. This can be invoked in the following way:

    \snippet code/doc_src_qmake-manual.pro 0

    Adding the \c build_all option to the \c CONFIG variable makes this rule
    the default when building the project.

    \note Each of the options specified in the \c CONFIG variable can also be
    used as a scope condition.
    You can test for the presence of certain configuration options by using the
    built-in \l{CONFIG(config)}{CONFIG()} function.
    For example, the following lines show the function as the condition in a scope
    to test whether only the \c opengl option is in use:

    \snippet qmake/configscopes.pro 4
    \snippet qmake/configscopes.pro 5

    This enables different configurations to be defined for \c release and
    \c debug builds. For more information, see \l{Scopes}{Using Scopes}.

    The following options define the type of project to be built.

    \note Some of these options only take effect when used on the relevant
    platform.

    \table
    \header \li Option \li Description
    \row    \li qt     \li The project is a Qt application and should link against the Qt
                      library. You can use the \c QT variable to control any additional
                      Qt modules that are required by your application.
                      This value is added by default, but you can remove it to
                      use qmake for a non-Qt project.
    \row    \li x11    \li The project is an X11 application or library.
                       This value is not needed if the target uses Qt.
    \endtable

    The \l{TEMPLATE}{application and library project templates} provide you with
    more specialized configuration options to fine tune the build process. The
    options are explained in detail in \l{Building Common Project Types}.

    For example, if your application uses the Qt library and you want to
    build it in \c debug mode, your project file will contain the following line:

    \snippet code/doc_src_qmake-manual.pro 1

    \note You must use "+=", not "=", or qmake
    will not be able to use Qt's configuration to determine the settings
    needed for your project.

    \section1 Declaring Qt Libraries

    If the \l{CONFIG} variable contains the \c qt value, qmake's support for Qt
    applications is enabled. This makes it possible to fine-tune which of the
    Qt modules are used by your application. This is achieved with the
    \l{Variables#QT}{QT} variable which can be used to declare the required
    extension modules.
    For example, we can enable the XML and network modules in the following way:

    \snippet code/doc_src_qmake-manual.pro 2

    \note \c QT includes the \c core and \c gui modules by default, so the
    above declaration \e adds the network and XML modules to this default list.
    The following assignment \e omits the default modules, and will lead to
    errors when the application's source code is being compiled:

    \snippet code/doc_src_qmake-manual.pro 3

    If you want to build a project \e without the \c gui module, you need to
    exclude it with the "-=" operator. By default, \c QT contains both
    \c core and \c gui, so the following line will result in a minimal
    Qt project being built:

    \snippet code/doc_src_qmake-manual.pro 4

    For a list of Qt modules that you can add to the \c QT variable, see
    \l{Variables#QT}{QT}.

    \section1 Configuration Features

    qmake can be set up with extra configuration
    features that are specified in feature (.prf) files. These extra features
    often provide support for custom tools that are used during the build
    process. To add a feature to the build process, append the feature name
    (the stem of the feature filename) to the \c CONFIG variable.

    For example, qmake can configure the build
    process to take advantage of external libraries that are supported by
    \l{http://www.freedesktop.org/wiki/Software/pkg-config}{pkg-config},
    such as the D-Bus and ogg libraries, with the following lines:

    \snippet code/doc_src_qmake-manual.pro 5

    For more information about adding features, see
    \l{Adding New Configuration Features}.

    \section1 Declaring Other Libraries

    If you are using other libraries in your project in addition to those
    supplied with Qt, you need to specify them in your project file.

    The paths that qmake searches for libraries
    and the specific libraries to link against can be added to the list of values in the
    \l{LIBS} variable. You can specify the paths to the libraries or use the
    Unix-style notation for specifying libraries and paths.

    For example, the following lines show how a library can be specified:

    \snippet code/doc_src_qmake-manual.pro 6

    The paths containing header files can also be specified in a similar way
    using the \l{INCLUDEPATH} variable.

    For example, to add several paths to be searched for header files:

    \snippet code/doc_src_qmake-manual.pro 7
*/

/*!
    \page qmake-running.html
    \title Running qmake
    \contentspage {qmake Manual}{Contents}
    \previouspage Building Common Project Types
    \nextpage Platform Notes

    The behavior of qmake can be customized when it
    is run by specifying various options on the command line. These allow the
    build process to be fine-tuned, provide useful diagnostic
    information, and can be used to specify the target platform for
    your project.

    \section1 Command Syntax

    The syntax used to run qmake takes the following simple form:

    \snippet code/doc_src_qmake-manual.pro 8

    \section1 Operating Modes

    qmake supports two different modes of operation. In the default mode, qmake
    uses the information in a project file to generate a Makefile, but it is also
    possible to use qmake to generate project files.
    If you want to explicitly set the mode, you must specify it before all
    other options. The \c mode can be either of the following two values:

    \list
    \li \c -makefile \BR
        qmake output will be a Makefile.
    \li \c -project \BR
        qmake output will be a project file. \BR
    \note It is likely that the created file will need to be edited. For example,
    adding the \c QT variable to suit what modules are required for the project.
    \endlist

    You can use the \c options to specify both general and mode-specific
    settings. Options that only apply to the Makefile mode are described in the
    \l{#MakefileMode}{Makefile Mode Options} section, whereas options that influence the
    creation of project files are described in the
    \l{#ProjectMode}{Project Mode Options} section.

    \section1 Files

    The \c files argument represents a list of one or more project files, separated
    by spaces.

    \section1 General Options

    A wide range of options can be specified on the command line to
    qmake in order to customize the build process,
    and to override default settings for your platform. The following basic
    options provide help on using qmake, specify where qmake writes the output
    file, and control the
    level of debugging information that will be written to the console:

    \list
    \li \c -help \BR
        qmake will go over these features and give some useful help.
    \li \c {-o file} \BR
        qmake output will be directed to \c file. If
        this option is not specified, qmake will try
        to use a suitable file name for its output, depending on the mode it is
        running in.\BR
        If '-' is specified, output is directed to stdout.
    \li \c -d \BR
        qmake will output debugging information. Adding \c -d more than once
        increases verbosity.
    \endlist

    The template used for the project is usually specified by the \l{TEMPLATE}
    variable in the project file. You can override or modify this by using the
    following options:

    \list
    \li \c {-t tmpl} \BR
        qmake will override any set \c TEMPLATE variables with \c tmpl, but only
        \e after the .pro file has been processed.
    \li \c {-tp prefix} \BR
        qmake will add \c prefix to the \c TEMPLATE variable.
    \endlist

    The level of warning information can be fine-tuned to help you find problems in
    your project file:

    \list
    \li \c -Wall \BR
        qmake will report all known warnings.
    \li \c -Wnone \BR
        No warning information will be generated by qmake.
    \li \c -Wparser \BR
        qmake will only generate parser warnings.
        This will alert you to common pitfalls and potential problems in the
        parsing of your project files.
    \li \c -Wlogic \BR
        qmake will warn of common pitfalls and
        potential problems in your project file. For example,
        qmake will report multiple occurrences of files in lists and missing
        files.
    \endlist

    \target MakefileMode
    \section1 Makefile Mode Options

    \snippet code/doc_src_qmake-manual.pro 9

    In Makefile mode, qmake will generate a Makefile
    that is used to build the project. Additionally, the following options may
    be used in this mode to influence the way the project file is generated:

    \list
    \li \c -after \BR
        qmake will process assignments given on the
        command line after the specified files.
    \li \c -nocache \BR
        qmake will ignore the \c{.qmake.cache} file.
    \li \c -nodepend \BR
        qmake will not generate any dependency
        information.
    \li \c {-cache file} \BR
        qmake will use \c file as the cache file,
        ignoring any other .qmake.cache files found.
    \li \c {-spec spec} \BR
        qmake will use \c spec as a path to platform and compiler information,
        and ignore the value of \l{QMAKESPEC}.
    \endlist

    You may also pass qmake assignments on the command line. They are processed
    before all of the files specified. For example, the following command
    generates a Makefile from test.pro:

    \snippet code/doc_src_qmake-manual.pro 10

    However, some of the specified options can be omitted as they are default
    values:

    \snippet code/doc_src_qmake-manual.pro 11

    If you are certain you want your variables processed after the
    files specified, then you may pass the \c -after option. When this
    is specified, all assignments on the command line after the \c -after
    option will be postponed until after the specified files are parsed.

    \target ProjectMode
    \section1 Project Mode Options

    \snippet code/doc_src_qmake-manual.pro 12

    In project mode, qmake will generate a project
    file. Additionally, you may supply the following options in this mode:

    \list
    \li \c -r \BR
       qmake will look through supplied directories recursively.
    \li \c -nopwd \BR
       qmake will not look in your current working directory for source code.
       It will only use the specified \c files.
    \endlist

    In this mode, the \c files argument can be a list of files or directories.
    If a directory is specified, it will be included in the \l{DEPENDPATH}
    variable, and relevant code from there will be included in the generated
    project file. If a file is given, it will be appended to the correct
    variable, depending on its extension. For example, UI files are added
    to \l{FORMS}, and C++ files are added to \l{SOURCES}.

    You may also pass assignments on the command line in this mode. When doing
    so, these assignments will be placed last in the generated project file.
*/

/*!
    \page qmake-platform-notes.html
    \title Platform Notes
    \contentspage {qmake Manual}{Contents}
    \previouspage Running qmake
    \nextpage qmake Language

    Many cross-platform projects can be handled by the basic qmake configuration
    features. However, on some platforms, it is sometimes useful, or even
    necessary, to take advantage of platform-specific features.
    qmake knows about many of these features, which can be accessed via specific
    variables that only take effect on the platforms where they are relevant.

    \section1 Mac OS X

    Features specific to this platform include support for creating universal
    binaries, frameworks and bundles.

    \section2 Source and Binary Packages

    The version of qmake supplied in source packages
    is configured slightly differently to that supplied in binary packages in
    that it uses a different feature specification. Where the source package
    typically uses the \c macx-g++ specification, the binary package is
    typically configured to use the \c macx-xcode specification.

    Users of each package can override this configuration by invoking
    qmake with the \c -spec option (see \l{Running qmake} for more information).
    For example, to use qmake from a binary package to create a Makefile in a
    project directory, invoke the following command:

    \snippet code/doc_src_qmake-manual.pro 13

    \section2 Using Frameworks

    qmake is able to automatically generate build
    rules for linking against frameworks in the standard framework directory on
    Mac OS X, located at \c{/Library/Frameworks/}.

    Directories other than the standard framework directory need to be specified
    to the build system, and this is achieved by appending linker options to the
    \l{QMAKE_LFLAGS} variable, as shown in the following example:

    \snippet code/doc_src_qmake-manual.pro 14

    The framework itself is linked in by appending the \c{-framework} options and
    the name of the framework to the \l{LIBS} variable:

    \snippet code/doc_src_qmake-manual.pro 15

    \section2 Creating Frameworks

    Any given library project can be configured so that the resulting library
    file is placed in a
    \l{http://developer.apple.com/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/WhatAreFrameworks.html}
    {framework}, ready for deployment. To do this, set up the project to use the
    \l{TEMPLATE}{\c lib template} and add the \c lib_bundle option to the
    \l{CONFIG} variable:

    \snippet code/doc_src_qmake-manual.pro 16

    The data associated with the library is specified using the
    \l{QMAKE_BUNDLE_DATA}
    variable. This holds items that will be installed with a library
    bundle, and is often used to specify a collection of header files,
    as in the following example:

    \snippet code/doc_src_qmake-manual.pro 17

    You use the \c FRAMEWORK_HEADERS variable to specify the headers required by
    a particular framework.
    Appending it to the \c QMAKE_BUNDLE_DATA variable ensures that
    information about these headers is added to the collection of
    resources that will be installed with the library bundle. Also, the
    framework name and version are specified by the \l {QMAKE_FRAMEWORK_BUNDLE_NAME}
    and \l{QMAKE_FRAMEWORK_VERSION} variables. By default, the values used for
    these variables are obtained from the \l{TARGET} and \l{VERSION} variables.

    See \l{Deploying an Application on Mac OS X} for more information about
    deploying applications and libraries.

    \section2 Creating and Moving Xcode Projects

    Developers on Mac OS X can take advantage of the qmake support for Xcode
    project files, as described in
    \l{Qt is Mac OS X Native#Development Tools}{Qt is Mac OS X Native},
    by running qmake to generate an Xcode project from an existing qmake project
    file. For example:

    \snippet code/doc_src_qmake-manual.pro 19

    \note If a project is later moved on the disk, qmake must be run again to
    process the project file and create a new Xcode project file.

    \section2 Supporting Two Build Targets Simultaneously

    Implementing this is currently not feasible, because the Xcode
    concept of Active Build Configurations is conceptually different
    from the qmake idea of build targets.

    The Xcode Active Build Configurations settings are for modifying
    Xcode configurations, compiler flags and similar build
    options. Unlike Visual Studio, Xcode does not allow for the
    selection of specific library files based on whether debug or
    release build configurations are selected. The qmake debug and
    release settings control which library files are linked to the
    executable.

    It is currently not possible to set files in Xcode configuration
    settings from the qmake generated Xcode project file. The way the
    libraries are linked in the \e {Frameworks & Libraries} phase in the
    Xcode build system.

    Furthermore, the selected \e {Active Build Configuration} is stored
    in a .pbxuser file, which is generated by Xcode on first load, not
    created by qmake.

    \section1 Windows

    Features specific to this platform include support for creating Visual
    Studio project files and handling manifest files when deploying Qt
    applications developed using Visual Studio 2005, or later.

    \section2 Creating Visual Studio Project Files

    Developers using Visual Studio to write Qt applications can use the
    Visual Studio integration facilities provided with the
    \l{Qt Commercial License}
    and do not need to worry about how project dependencies are managed.

    However, some developers may need to import an existing
    qmake project into Visual Studio.
    qmake is able to take a project file and create
    a Visual Studio project that contains all the necessary information
    required by the development environment. This is achieved by setting the
    qmake \l{TEMPLATE}{project template} to either \c vcapp
    (for application projects) or \c vclib (for library projects).

    This can also be set using a command line option, for example:

    \snippet code/doc_src_qmake-manual.pro 20

    It is possible to recursively generate \c{.vcproj} files in subdirectories
    and a \c{.sln} file in the main directory, by typing:

    \snippet code/doc_src_qmake-manual.pro 21

    Each time you update the project file, you need to run
    qmake to generate an updated Visual Studio
    project.

    \note If you are using the Visual Studio Add-in, select \gui Qt >
    \gui{Import from .pro file} to import \c .pro files.

    \section2 Visual Studio Manifest Files

    When deploying Qt applications built using Visual Studio 2005, or later,
    make sure that the manifest file that was created when the application
    was linked is handled correctly. This is handled automatically for
    projects that generate DLLs.

    Removing manifest embedding for application executables can be done with
    the following assignment to the \l{CONFIG} variable:

    \snippet code/doc_src_qmake-manual.pro 22

    Also, the manifest embedding for DLLs can be removed with the following
    assignment to the \c CONFIG variable:

    \snippet code/doc_src_qmake-manual.pro 23

    This is discussed in more detail in the
    \l{Deploying an Application on Windows#Manifest files}
    {deployment guide for Windows}.
*/

/*!
    \page qmake-reference.html
    \title Reference
    \contentspage {qmake Manual}{Contents}
    \previouspage Configuring qmake
    \nextpage Variables

    The reference sections describe in detail the variables and functions that
    are available for use in qmake project files.

    \section1 Variable Reference

    \l{Variables} describes the variables that are recognized by qmake when
    configuring the build process for projects.

    \section1 Function Reference

    There are two types of qmake functions: replace functions and test
    functions. Replace functions return a value list, while test functions
    return a boolean result. The functions are implemented in two places:
    fundamental functionality is offered as built-in functions. More complex
    functions are implemented in a library of feature files (.prf).

    The functions are divided into categories according to their type:

    \list
        \li \l{Replace Functions}
        \li \l{Test Functions}
    \endlist
*/

/*!
    \page qmake-variable-reference.html
    \title Variables
    \contentspage {qmake Manual}{Contents}
    \previouspage Reference
    \nextpage Replace Functions
    \keyword qmake Variable Reference

    The fundamental behavior of qmake is influenced by variable declarations that
    define the build process of each project. Some of these declare resources,
    such as headers and source files, that are common to each platform. Others
    are used to customize the behavior of compilers and linkers on specific
    platforms.

    Platform-specific variables follow the naming pattern of the
    variables which they extend or modify, but include the name of the relevant
    platform in their name. For example, \c QMAKE_LIBS can be used to specify a list
    of libraries that a project needs to link against, and \c QMAKE_LIBS_X11 can be
    used to extend or override this list.

    \target CONFIG
    \section1 CONFIG

    Specifies project configuration and compiler options. The values are
    recognized internally by qmake and have special meaning.

    The following \c CONFIG values control compilation flags:

    \table
    \header \li Option   \li Description
    \row    \li release  \li The project is to be built in release mode.
            If \c debug is also specified, the last one takes effect.
    \row    \li debug    \li The project is to be built in debug mode.
    \row    \li debug_and_release \li The project is prepared to be built in
            \e both debug and release modes.
    \row    \li debug_and_release_target \li This option is set by default. If
            \c debug_and_release is also set, the debug and release builds
            end up in separate debug and release directories.
    \row    \li build_all \li If \c debug_and_release is specified, the project is
            built in both debug and release modes by default.
    \row    \li autogen_precompile_source \li Automatically generates a \c .cpp
            file that includes the precompiled header file specified in the .pro
            file.
    \row    \li ordered  \li When using the \c subdirs template, this option
            specifies that the directories listed should be processed in the
            order in which they are given.
    \row    \li precompile_header \li Enables support for the use of
            \l{Using Precompiled Headers}{precompiled headers} in projects.
    \row    \li warn_on  \li The compiler should output as many warnings as possible.
            If \c warn_off is also specified, the last one takes effect.
    \row    \li warn_off \li The compiler should output as few warnings as possible.
    \row    \li exceptions \li Exception support is enabled. Set by default.
    \row    \li exceptions_off \li Exception support is disabled.
    \row    \li rtti \li RTTI support is enabled. By default, the compiler
            default is used.
    \row    \li rtti_off \li RTTI support is disabled. By default, the compiler
            default is used.
    \row    \li stl \li STL support is enabled. By default, the compiler
            default is used.
    \row    \li stl_off \li STL support is disabled. By default, the compiler
            default is used.
    \row    \li thread \li Thread support is enabled. This is enabled when CONFIG
            includes \c qt, which is the default.
    \row    \li c++11 \li C++11 support is enabled. This option has no effect if
            the compiler does not support C++11.
            By default, support is disabled.
    \endtable

    Since the \c debug option overrides the \c release option when both are
    defined in the \c CONFIG variable, it is necessary to use the
    \c debug_and_release option if you want to allow both debug and release
    versions of a project to be built. In such a case, the Makefile that
    qmake generates includes a rule that builds both
    versions, and this can be invoked in the following way:

    \snippet code/doc_src_qmake-manual.pro 24

    When linking a library, qmake relies on the
    underlying platform to know what other libraries this library links
    against. However, if linking statically, qmake
    will not get this information unless we use the following \c CONFIG
    options:

     \table
     \header \li Option   \li Description
     \row    \li create_prl  \li This option enables
        qmake to track these dependencies. When this
        option is enabled, qmake will create a file
        with the extension \c .prl which will save meta-information about the library
        (see \l{LibDepend}{Library Dependencies} for more info).
     \row    \li link_prl    \li When this option is enabled,
        qmake will process all libraries linked to
        by the application and find their meta-information (see
        \l{LibDepend}{Library Dependencies} for more info).
     \endtable

    \note The \c create_prl option is required when \e {building} a
    static library, while \c link_prl is required when \e {using} a
    static library.

    On Windows (or if Qt is configured with \c{-debug-and-release}), add the
    \c build_all option to the \c CONFIG variable to build all build
    configurations by default.

    Additionally, adding \c debug_and_release to the \c CONFIG variable will
    cause both \c debug and \c release to be defined in the contents of
    \c CONFIG. When the project file is processed, the
    \l{Scopes}{scopes} that test for each value will be
    processed for \e both debug and release modes. The \c{build_pass} variable
    will be set for each of these modes, and you can test for this to perform
    build-specific tasks. For example:

    \snippet code/doc_src_qmake-manual.pro 25

    As a result, it may be useful to define mode-specific variables, such as
    \l{#QMAKE_LFLAGS_RELEASE}{QMAKE_LFLAGS_RELEASE}, instead of general
    variables, such as \l{#QMAKE_LFLAGS}{QMAKE_LFLAGS}, where possible.

    The following options define the application or library type:

    \table
    \header \li Option \li Description
    \row \li qt \li The target is a Qt application or library and requires the Qt
         library and header files. The proper include and library paths for the
         Qt library will automatically be added to the project. This is defined
         by default, and can be fine-tuned with the \c{\l{#qt}{QT}} variable.
    \row \li thread \li The target is a multi-threaded application or library.  The
        proper defines and compiler flags will automatically be added to
        the project. This value is set by default.
    \row \li x11 \li The target is a X11 application or library. The proper
        include paths and libraries will automatically be added to the
        project.
    \row \li testcase \li The target is an automated test.
        \l{Building Common Project Types#building-a-testcase}{A check target} will be added
        to the generated Makefile to run the test. Only relevant when generating
        Makefiles.
    \row \li insignificant_test \li The exit code of the automated test will be ignored.
        Only relevant if \c testcase is also set.
    \row \li windows \li The target is a Win32 window application (app only). The
        proper include paths, compiler flags and libraries will
        automatically be added to the project.
    \row \li console \li The target is a Win32 console application (app only). The
        proper include paths, compiler flags and libraries will
        automatically be added to the project.
    \row \li shared \li{1,2} The target is a shared object/DLL. The proper
        include paths, compiler flags and libraries will automatically be
        added to the project. Note that \c dll can also be used on all platforms;
        a shared library file with the appropriate suffix for the target platform
        (.dll or .so) will be created.
    \row \li dll
    \row \li static \li{1,2} The target is a static library (lib only).  The proper
        compiler flags will automatically be added to the project.
    \row \li staticlib
    \row \li plugin \li The target is a plugin (lib only). This enables dll as well.
    \row \li designer \li The target is a plugin for \QD.
    \row \li no_lflags_merge \li Ensures that the list of libraries stored in the
         \c LIBS variable is not reduced to a list of unique values before it is used.
    \row \li resources \li Configures qmake to run rcc on the content of \c RESOURCES
         if defined.
    \endtable

    These options define specific features on Windows only:

    \table
    \header \li Option \li Description
    \row \li flat \li When using the vcapp template this will put all the source
         files into the source group and the header files into the header group
         regardless of what directory they reside in.  Turning this
         option off will group the files within the source/header group depending
         on the directory they reside. This is turned on by default.
    \row \li embed_manifest_dll \li Embeds a manifest file in the DLL created
         as part of a library project.
    \row \li embed_manifest_exe \li Embeds a manifest file in the DLL created
         as part of an application project.
    \row \li incremental \li Used to enable or disable incremental linking in Visual
         C++, depending on whether this feature is enabled or disabled by default.
    \endtable

    See \l{Platform Notes#Visual Studio Manifest Files}{Platform Notes}
    for more information about the options for embedding manifest files.

    The following options take an effect only on Mac OS X:

    \table
    \header \li Option \li Description
    \row \li ppc \li Builds a PowerPC binary.
    \row \li x86 \li Builds an i386 compatible binary.
    \row \li app_bundle \li Puts the executable into a bundle (this is the default).
    \row \li lib_bundle \li Puts the library into a library bundle.
    \endtable

    The build process for bundles is also influenced by
    the contents of the \l{#QMAKE_BUNDLE_DATA}{QMAKE_BUNDLE_DATA} variable.

    The following options take an effect only on Linux/Unix platforms:

    \table
    \header \li Option \li Description
    \row \li largefile \li Includes support for large files.
    \row \li separate_debug_info \li Puts debugging information for libraries in
    separate files.
    \endtable

    The \c CONFIG variable will also be checked when resolving scopes. You may
    assign anything to this variable.

    For example:

    \snippet code/doc_src_qmake-manual.pro 26

    \target DEFINES
    \section1 DEFINES

    qmake adds the values of this variable as
    compiler C preprocessor macros (-D option).

    For example:

    \snippet code/doc_src_qmake-manual.pro 27

    \target DEF_FILE
    \section1 DEF_FILE

    \note This variable is used only on Windows when using the \c app template.

    Specifies a \c .def file to be included in the project.

    \target DEPENDPATH
    \section1 DEPENDPATH

    Specifies a list of all directories to look in to resolve dependencies. This
    variable is used when crawling through \c included files.

    \target DEPLOYMENT
    \section1 DEPLOYMENT

    \note This variable is used only on the Windows CE platform.

    Specifies which additional files will be deployed. Deployment means the
    transfer of files from the development system to the target device or
    emulator.

    Files can be deployed by either creating a Visual Studio project or using
    the \l {Using Qt Test remotely on Windows CE}{cetest} executable.

    For example, the following definition uploads all PNG images in \c path to
    the directory where the build target is deployed:

    \snippet code/doc_src_qmake-manual.pro 28

    The default deployment target path for Windows CE is
    \c{%CSIDL_PROGRAM_FILES%\target}, which usually gets expanded to
    \c{\Program Files\target}.

    It is also possible to specify multiple \c sources to be deployed on
    target \c paths. In addition, different variables can be used for
    deployment to different directories.

    For example:

    \snippet code/doc_src_qmake-manual.pro 29

    \note In Windows CE all linked Qt libraries will be deployed to the path
    specified by \c{myFiles.path}.

    \target DEPLOYMENT_PLUGIN
    \section1 DEPLOYMENT_PLUGIN

    \note This variable is used only on the Windows CE platform.

    Specifies the Qt plugins that will be deployed. All plugins
    available in Qt can be explicitly deployed to the device. See
    \l{Static Plugins}{Static Plugins} for a complete list.

    \note No plugins will be deployed automatically to Windows CE devices.
    If the application depends on plugins, these plugins have to be specified
    manually.

    For example, the following definition uploads the jpeg imageformat plugin to
    the plugins directory on the Windows CE device:

    \snippet code/doc_src_qmake-manual.pro 142

    \target DESTDIR
    \section1 DESTDIR

    Specifies where to put the \l{#TARGET}{target} file.

    For example:

    \snippet code/doc_src_qmake-manual.pro 30

    \target DISTFILES
    \section1 DISTFILES

    Specifies a list of files to be included in the dist
    target. This feature is supported by UnixMake specs only.

    For example:

    \snippet code/doc_src_qmake-manual.pro 31

    \target DLLDESTDIR
    \section1 DLLDESTDIR

    \note This variable applies only to Windows targets.

    Specifies where to copy the \l{#TARGET}{target} dll.

    \target FORMS
    \section1 FORMS

    Specifies the UI files (see \l{Qt Designer Manual}) to be processed by \c uic
    before compiling.  All dependencies, headers and source files required
    to build these UI files will automatically be added to the project.

    For example:

    \snippet code/doc_src_qmake-manual.pro 32

    \target GUID
    \section1 GUID

    Specifies the GUID that is set inside a \c{.vcproj} file. The GUID is
    usually randomly determined. However, should you require a fixed GUID,
    it can be set using this variable.

    This variable is specific to \c{.vcproj} files only; it is ignored
    otherwise.

    \target HEADERS
    \section1 HEADERS

    Defines the header files for the project.

    qmake automatically detects whether \l{moc} is required by the classes in
    the headers, and adds the appropriate dependencies and files to the project
    for generating and linking the moc files.

    For example:

    \snippet code/doc_src_qmake-manual.pro 34

    See also \l{#SOURCES}{SOURCES}.

    \target ICON
    \section1 ICON

    This variable is used only on Mac OS to set the application icon.
    Please see \l{Setting the Application Icon}{the application icon documentation}
    for more information.

    \target INCLUDEPATH
    \section1 INCLUDEPATH

    Specifies the #include directories which should be
    searched when compiling the project.

    For example:

    \snippet code/doc_src_qmake-manual.pro 35

    To specify a path containing spaces, quote the path using the technique
    described in \l{Whitespace}.

    \snippet qmake/spaces.pro quoting include paths with spaces

    \target INSTALLS
    \section1 INSTALLS

    Specifies a list of resources that will be installed when
    \c{make install} or a similar installation procedure is executed. Each
    item in the list is typically defined with attributes that provide
    information about where it will be installed.

    For example, the following \c{target.path} definition describes where the
    build target will be installed, and the \c INSTALLS assignment adds the
    build target to the list of existing resources to be installed:

    \snippet code/doc_src_qmake-manual.pro 36

    For more information, see \l{Installing Files}.

    \target LEXIMPLS
    \section1 LEXIMPLS

    Specifies a list of Lex implementation files.  The value
    of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target LEXOBJECTS
    \section1 LEXOBJECTS

    Specifies the names of intermediate Lex object
    files.The value of this variable is typically handled by
    qmake and rarely needs to be modified.

    \target LEXSOURCES
    \section1 LEXSOURCES

    Specifies a list of Lex source files.  All
    dependencies, headers and source files will automatically be added to
    the project for building these lex files.

    For example:

    \snippet code/doc_src_qmake-manual.pro 37

    \target LIBS
    \section1 LIBS

    Specifies a list of libraries to be linked into the project.
    If you use the Unix \c -l (library) and -L (library path) flags, qmake
    handles the libraries correctly on Windows (that is, passes the full path of
    the library to the linker). The library must exist for
    qmake to find the directory where a \c -l lib is located.

    For example:

    \snippet code/doc_src_qmake-manual.pro 38

    To specify a path containing spaces, quote the path using the technique
    described in \l{Whitespace}.

    \snippet qmake/spaces.pro quoting library paths with spaces

    By default, the list of libraries stored in \c LIBS is reduced to a list of
    unique names before it is used. To change this behavior, add the
    \c no_lflags_merge option to the \l{CONFIG} variable:

    \snippet code/doc_src_qmake-manual.pro 39

    \target LITERAL_HASH
    \section1 LITERAL_HASH

    This variable is used whenever a literal hash character (\c{#}) is needed in
    a variable declaration, perhaps as part of a file name or in a string passed
    to some external application.

    For example:

    \snippet qmake/comments.pro 1

    By using \c LITERAL_HASH in this way, the \c # character can be used
    to construct a URL for the \c message() function to print to the console.

    \target MAKEFILE
    \section1 MAKEFILE

    Specifies the name of the generated Makefile. The value of this variable is
    typically handled by qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to
    be modified.

    \target MAKEFILE_GENERATOR
    \section1 MAKEFILE_GENERATOR

    Specifies the name of the Makefile generator to use
    when generating a Makefile.  The value of this variable is typically
    handled internally by qmake and rarely needs to
    be modified.

    \target MOC_DIR
    \section1 MOC_DIR

    Specifies the directory where all intermediate moc
    files should be placed.

    For example:

    \snippet code/doc_src_qmake-manual.pro 40

    \target OBJECTS
    \section1 OBJECTS

    This variable is automatically populated from the \l{SOURCES} variable.
    The extension of each source file is replaced by .o (Unix) or .obj (Win32).
    You can add objects to the list.

    \target OBJECTS_DIR
    \section1 OBJECTS_DIR

    Specifies the directory where all intermediate
    objects should be placed.

    For example:

    \snippet code/doc_src_qmake-manual.pro 41

    \target POST_TARGETDEPS
    \section1 POST_TARGETDEPS

    Lists the libraries that the \l{#TARGET}{target} depends on. Some backends,
    such as the generators for Visual Studio and Xcode project files, do not
    support this variable. Generally, this variable is supported internally by
    these build tools, and it is useful for explicitly listing dependent static
    libraries.

    This list is placed after all builtin (and \link #PRE_TARGETDEPS
    $$PRE_TARGETDEPS \endlink) dependencies.

    \target PRE_TARGETDEPS
    \section1 PRE_TARGETDEPS

    Lists libraries that the \l{#TARGET}{target} depends on. Some backends,
    such as the generators for Visual Studio and Xcode project files, do not
    support this variable. Generally, this variable is supported internally by
    these build tools, and it is useful for explicitly listing dependent static
    libraries.

    This list is placed before all builtin dependencies.

    \target PRECOMPILED_HEADER
    \section1 PRECOMPILED_HEADER

    Indicates the header file for creating a precompiled
    header file, to increase the compilation speed of a project.
    Precompiled headers are currently only supported on some platforms
    (Windows - all MSVC project types, Mac OS X - Xcode, Makefile,
    Unix - gcc 3.3 and up).

    \target PWD
    \section1 PWD

    Specifies the full path leading to the directory
    containing the current file being parsed. This can be useful
    to refer to files within the source tree when writing project files to
    support shadow builds.

    See also \l{#_PRO_FILE_PWD_}{_PRO_FILE_PWD_}.

    \note Do not attempt to overwrite the value of this variable.

    \target OUT_PWD
    \section1 OUT_PWD

    Specifies the full path leading to the directory where qmake places the
    generated Makefile.

    \note Do not attempt to overwrite the value of this variable.

    \target QMAKE_systemvariable
    \section1 QMAKE

    Specifies the name of the qmake program itself and is placed in generated
    Makefiles. The value of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKESPEC_systemvariable
    \section1 QMAKESPEC

    A system variable that contains the full path of the qmake configuration that is used
    when generating Makefiles. The value of this variable is automatically computed.

    \note Do not attempt to overwrite the value of this variable.

    \target QMAKE_AR_CMD
    \section1 QMAKE_AR_CMD

    \note This variable is used on Unix platforms only.

    Specifies the command to execute when creating a shared library. The value of this variable
    is typically handled by qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_BUNDLE_DATA
    \section1 QMAKE_BUNDLE_DATA

    \note This variable is used on Mac OS X only.

    Specifies the data that will be installed with a library
    bundle, and is often used to specify a collection of header files.

    For example, the following lines add \c path/to/header_one.h
    and \c path/to/header_two.h to a group containing information about the
    headers supplied with the framework:

    \snippet code/doc_src_qmake-manual.pro 43

    The last line adds the information about the headers to the collection of
    resources that will be installed with the library bundle.

    Library bundles are created when the \c lib_bundle option is added to the
    \l{#CONFIG}{CONFIG} variable.

    See \l{Platform Notes#Creating Frameworks}{Platform Notes} for
    more information about creating library bundles.

    \section1 QMAKE_BUNDLE_EXTENSION

    \note This variable is used on Mac OS X only.

    Specifies the extension to be used for library bundles.
    This allows frameworks to be created with custom extensions instead of the
    standard \c{.framework} directory name extension.

    For example, the following definition will result in a framework with the
    \c{.myframework} extension:

    \snippet code/doc_src_qmake-manual.pro 44

    \section1 QMAKE_CC

    Specifies the C compiler that will be used when building
    projects containing C source code. Only the file name of the compiler
    executable needs to be specified as long as it is on a path contained
    in the \c PATH variable when the Makefile is processed.

    \target QMAKE_CFLAGS_DEBUG
    \section1 QMAKE_CFLAGS_DEBUG

    Specifies the C compiler flags for debug builds.
    The value of this variable is typically handled by qmake or \l{#QMAKESPEC}{qmake.conf} and
    rarely needs to be modified.

    \target QMAKE_CFLAGS_RELEASE
    \section1 QMAKE_CFLAGS_RELEASE

    Specifies the C compiler flags for release builds.
    The value of this variable is typically handled by qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \target QMAKE_CFLAGS_SHLIB
    \section1 QMAKE_CFLAGS_SHLIB

    \note This variable is used on Unix platforms only.

    Specifies the compiler flags for creating a shared
    library. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_CFLAGS_THREAD
    \section1 QMAKE_CFLAGS_THREAD

    Specifies the compiler flags for creating a multi-threaded
    application. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_CFLAGS_WARN_OFF
    \section1 QMAKE_CFLAGS_WARN_OFF

    This variable is used only when the \c {warn_off} \l{#CONFIG}{CONFIG} option
    is set. The value of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CFLAGS_WARN_ON
    \section1 QMAKE_CFLAGS_WARN_ON

    This variable is used only when the \c {warn_on} \l{#CONFIG}{CONFIG} option
    is set. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CLEAN
    \section1 QMAKE_CLEAN

    Specifies a list of generated files (by \l{moc} and \l{uic}, for example) and
    object files to be removed by \c {make clean}.

    \section1 QMAKE_CXX

    Specifies the C++ compiler that will be used when building
    projects containing C++ source code. Only the file name of the compiler
    executable needs to be specified as long as it is on a path contained
    in the \c PATH variable when the Makefile is processed.

    \section1 QMAKE_CXXFLAGS

    Specifies the C++ compiler flags for building
    a project. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified. The flags specific to debug and release modes can be
    adjusted by modifying the \c QMAKE_CXXFLAGS_DEBUG and
    \c QMAKE_CXXFLAGS_RELEASE variables, respectively.

    \target QMAKE_CXXFLAGS_DEBUG
    \section1 QMAKE_CXXFLAGS_DEBUG

    Specifies the C++ compiler flags for debug builds.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CXXFLAGS_RELEASE
    \section1 QMAKE_CXXFLAGS_RELEASE

    Specifies the C++ compiler flags for release builds.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CXXFLAGS_SHLIB
    \section1 QMAKE_CXXFLAGS_SHLIB

    Specifies the C++ compiler flags for creating a shared library.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_CXXFLAGS_THREAD
    \section1 QMAKE_CXXFLAGS_THREAD

    Specifies the C++ compiler flags for creating a multi-threaded application.
    The value of this variable is typically handled by qmake or \l{#QMAKESPEC}
    {qmake.conf} and rarely needs to be modified.

    \target QMAKE_CXXFLAGS_WARN_OFF
    \section1 QMAKE_CXXFLAGS_WARN_OFF

    Specifies the C++ compiler flags for suppressing compiler
    warnings. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_CXXFLAGS_WARN_ON
    \section1 QMAKE_CXXFLAGS_WARN_ON

    Specifies C++ compiler flags for generating compiler warnings.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_DISTCLEAN
    \section1 QMAKE_DISTCLEAN

    Specifies a list of files to be removed by \c{make distclean}.

    \target QMAKE_EXTENSION_SHLIB
    \section1 QMAKE_EXTENSION_SHLIB

    Contains the extension for shared libraries.  The value of
    this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \note Platform-specific variables that change the extension override
    the contents of this variable.

    \section1 QMAKE_EXT_MOC

    Contains the extension used on included moc files.

    See also \l{Configuring qmake#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_UI

    Contains the extension used on \QD UI files.

    See also \l{Configuring qmake#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_PRL

    Contains the extension used on created PRL files.

    See also \l{Configuring qmake#Extensions}{File Extensions},
             \l{LibDepend}{Library Dependencies}.

    \section1 QMAKE_EXT_LEX

    Contains the extension used on files given to Lex.

    See also \l{Configuring qmake#Extensions}{File Extensions},
             \l{#LEXSOURCES}{LEXSOURCES}.

    \section1 QMAKE_EXT_YACC
    Contains the extension used on files given to Yacc.

    See also \l{Configuring qmake#Extensions}{File Extensions},
             \l{#YACCSOURCES}{YACCSOURCES}.

    \section1 QMAKE_EXT_OBJ

    Contains the extension used on generated object files.

    See also \l{Configuring qmake#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_CPP

    Contains suffixes for files that should be interpreted as C++ source code.

    See also \l{Configuring qmake#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_H

    Contains suffixes for files which should be interpreted as C header files.

    See also \l{Configuring qmake#Extensions}{File Extensions}.

        \section1 QMAKE_EXTRA_COMPILERS

    Specifies a list of additional compilers or preprocessors.

    See also \l{Adding Compilers}.

        \section1 QMAKE_EXTRA_TARGETS

    Specifies a list of additional qmake targets.

    See also \l{Adding Custom Targets}.

    \target QMAKE_FAILED_REQUIREMENTS
    \section1 QMAKE_FAILED_REQUIREMENTS

    Contains the list of failed requirements.
    The value of this variable is set by qmake and cannot be modified.

    See also \l{requires(condition)}{requires()} and \l{REQUIRES}.

    \section1 QMAKE_FRAMEWORK_BUNDLE_NAME

    \note This variable is used on Mac OS X only.

    In a framework project, this variable contains the name to be used for the
    framework that is built.

    By default, this variable contains the same value as the \l{#TARGET}{TARGET}
    variable.

    See \l{Creating Frameworks} for
    more information about creating frameworks and library bundles.

    \target QMAKE_FRAMEWORK_VERSION
    \section1 QMAKE_FRAMEWORK_VERSION

    \note This variable is used on Mac OS X only.

    For projects where the build target is a Mac OS X framework, this variable
    is used to specify the version number that will be applied to the framework
    that is built.

    By default, this variable contains the same value as the \l{#VERSION}{VERSION}
    variable.

    See \l{Creating Frameworks} for more information about creating frameworks.

    \target QMAKE_INCDIR
    \section1 QMAKE_INCDIR

    Specifies the list of system header paths that are appended to \l{INCLUDEPATH}.
    The value of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_INCDIR_EGL
    \section1 QMAKE_INCDIR_EGL

    Specifies the location of EGL header files to be added to
    \l{INCLUDEPATH} when building a target with OpenGL/ES or OpenVG support.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_INCDIR_OPENGL
    \section1 QMAKE_INCDIR_OPENGL

    Specifies the location of OpenGL header files to be added
    to \l{INCLUDEPATH} when building a target with OpenGL support. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    If the OpenGL implementation uses EGL (most OpenGL/ES systems),
    then QMAKE_INCDIR_EGL may also need to be set.

    \section1 QMAKE_INCDIR_OPENGL_ES1, QMAKE_INCDIR_OPENGL_ES2

    These variables specify the location of OpenGL headers files to be added
    to \l{INCLUDEPATH} when building a target with OpenGL ES 1
    or OpenGL ES 2 support respectively.

    The value of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    If the OpenGL implementation uses EGL (most OpenGL/ES systems),
    then QMAKE_INCDIR_EGL may also need to be set.

    \target QMAKE_INCDIR_OPENVG
    \section1 QMAKE_INCDIR_OPENVG

    Specifies the location of OpenVG header files to be added
    to \l{INCLUDEPATH} when building a target with OpenVG support. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    If the OpenVG implementation uses EGL then QMAKE_INCDIR_EGL may also
    need to be set.

    \target QMAKE_INCDIR_X11
    \section1 QMAKE_INCDIR_X11

    \note This variable is used on Unix platforms only.

    Specifies the location of X11 header file paths to be added
    to \l{INCLUDEPATH} when building a X11 target. The value of this variable
    is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_INFO_PLIST
    \section1 QMAKE_INFO_PLIST

    \note This variable is used on Mac OS X platforms only.

    Specifies the name of the property list file, \c{.plist}, you
    would like to include in your Mac OS X application bundle.

    In the \c{.plist} file, you can define some variables, e.g., @EXECUTABLE@,
    which qmake will replace with the actual executable name. Other variables
    include @ICON@, @TYPEINFO@, @LIBRARY@, and @SHORT_VERSION@.

    \note Most of the time, the default \c{Info.plist} is good enough.

    \section1 QMAKE_LFLAGS

    Specifies a general set of flags that are passed to
    the linker. If you need to change the flags used for a particular
    platform or type of project, use one of the specialized variables
    for that purpose instead of this variable.

    \target QMAKE_LFLAGS_CONSOLE
    \section1 QMAKE_LFLAGS_CONSOLE

    \note This variable is used on Windows only.

    Specifies the linker flags for building console programs. The value
    of this variable is typically handled by qmake
    or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_DEBUG

    Specifies the linker flags for debug builds.
    The value of this variable is typically handled by qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_PLUGIN

    Specifies the linker flags for building plugins. The value of this
    variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_RPATH

    \note This variable is used on Unix platforms only.

    Specifies the linker flags needed to use the values from \l{QMAKE_RPATHDIR}.

    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_RPATHLINK

    Specifies the linker flags needed to use the values from
    \l{QMAKE_RPATHLINKDIR}.

    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_RELEASE

    Specifies the linker flags for release builds.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_APP

    Specifies the linker flags for building applications.
    The value of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_SHLIB

    Specifies the linker flags used for building shared libraries.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_LFLAGS_SONAME

    Specifies the linker flags for setting the name of shared objects,
    such as .so or .dll. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_LFLAGS_THREAD

    Specifies the linker flags for building multi-threaded projects.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_LFLAGS_WINDOWS

    \note This variable is used on Windows only.

    Specifies the linker flags for building Windows GUI projects (that is,
    non-console applications). The value of this variable is typically handled
    by qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_LIBDIR

    Specifies a list of system library paths.
    The value of this variable is typically handled by qmake
    or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBDIR_FLAGS

    \note This variable is used on Unix platforms only.

    Specifies the location of all library directories with -L
    prefixed. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_LIBDIR_EGL

    Specifies the location of the EGL library directory, when EGL
    is used with OpenGL/ES or OpenVG. The value of this variable is typically
    handled by qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \section1 QMAKE_LIBDIR_OPENGL

    Specifies the location of the OpenGL library directory. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    If the OpenGL implementation uses EGL (most OpenGL/ES systems),
    then QMAKE_LIBDIR_EGL may also need to be set.

    \section1 QMAKE_LIBDIR_OPENVG

    Specifies the location of the OpenVG library directory. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    If the OpenVG implementation uses EGL, then QMAKE_LIBDIR_EGL
    may also need to be set.

    \section1 QMAKE_LIBDIR_X11

    \note This variable is used on Unix platforms only.

    Specifies the location of the X11 library directory. The value
    of this variable is typically handled by qmake
    or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS

    Specifies all project libraries. The value of this variable
    is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_EGL

    Specifies all EGL libraries when building Qt with OpenGL/ES
    or OpenVG.  The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.  The usual value is \c{-lEGL}.

    \section1 QMAKE_LIBS_OPENGL

    Specifies all OpenGL libraries.  The value of this variable
    is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    If the OpenGL implementation uses EGL (most OpenGL/ES systems),
    then QMAKE_LIBS_EGL may also need to be set.

    \section1 QMAKE_LIBS_OPENGL_ES1, QMAKE_LIBS_OPENGL_ES2

    These variables specify all the OpenGL libraries for OpenGL ES 1
    and OpenGL ES 2.

    The value of these variables is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    If the OpenGL implementation uses EGL (most OpenGL/ES systems),
    then QMAKE_LIBS_EGL may also need to be set.

    \section1 QMAKE_LIBS_OPENVG

    Specifies all OpenVG libraries.  The value of this variable
    is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.  The usual
    value is \c{-lOpenVG}.

    Some OpenVG engines are implemented on top of OpenGL.  This will
    be detected at configure time and QMAKE_LIBS_OPENGL will be implicitly
    added to QMAKE_LIBS_OPENVG wherever the OpenVG libraries are linked.

    If the OpenVG implementation uses EGL, then QMAKE_LIBS_EGL may also
    need to be set.

    \section1 QMAKE_LIBS_THREAD

    \note This variable is used on Unix platforms only.

    Specifies all libraries that need to be linked against when
    building a multi-threaded target. The value of this variable is
    typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_X11

    \note This variable is used on Unix platforms only.

    Specifies all X11 libraries. The value of this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIB_FLAG

    This variable is not empty if the \c lib template is specified. The value
    of this variable is typically handled by qmake
    or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LINK_SHLIB_CMD

    Specifies the command to execute when creating a shared
    library. The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_LN_SHLIB

    Specifies the command to execute when creating a link to a shared library. The
    value of this variable is typically handled by qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_POST_LINK

    Specifies the command to execute after linking the \l{TARGET}
    together. This variable is normally empty and therefore nothing is
    executed.

    \note This variable takes no effect on Xcode projects.

    \section1 QMAKE_PRE_LINK

    Specifies the command to execute before linking the \l{TARGET}
    together. This variable is normally empty and therefore nothing is
    executed.

    \note This variable takes no effect on Xcode projects.

    \section1 QMAKE_PROJECT_NAME

    \note This variable is used for Visual Studio project files only.

    Determines the name of the project when generating project
    files for IDEs. The default value is the target name. The value of this
    variable is typically handled by qmake and rarely needs to be modified.

    \section1 QMAKE_MAC_SDK

    This variable is used on Mac OS X when building universal binaries.

    \section1 QMAKE_MACOSX_DEPLOYMENT_TARGET

    This variable only takes effect when building on Mac OS X. On that
    platform, the variable will be forwarded to the MACOSX_DEPLOYMENT_TARGET
    environment variable, which is interpreted by the compiler or linker.
    For more information, see the
    \l{Deploying an Application on Mac OS X#Mac OS X Version Dependencies}{Deploying
    an Application on Mac OS X} document.

    \section1 QMAKE_MAKEFILE

    Specifies the name of the Makefile to create. The value of
    this variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_QMAKE

    Contains the abosolute path of the qmake executable.

    \note Do not attempt to overwrite the value of this variable.

    \section1 QMAKE_RESOURCE_FLAGS

    This variable is used to customize the list of options passed to the
    \l{rcc}{Resource Compiler} in each of the build rules where it is used.
    For example, the following line ensures that the \c{-threshold} and
    \c{-compress} options are used with particular values each time that
    \c rcc is invoked:

    \snippet code/doc_src_qmake-manual.pro 45

    \section1 QMAKE_RPATHDIR

    \note This variable is used on Unix platforms only.

    Specifies a list of library paths that are added to the
    executable at link time so that the paths will be preferentially
    searched at runtime.

    \section1 QMAKE_RPATHLINKDIR

    Specifies a list of library paths for the static linker to search for implicit
    dependencies of shared libraries. For more information, see the manual page
    for \c ld(1).

    \section1 QMAKE_RUN_CC

    Specifies the individual rule needed to build an object. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_RUN_CC_IMP

    Specifies the individual rule needed to build an object. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_RUN_CXX

    Specifies the individual rule needed to build an object. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_RUN_CXX_IMP

    Specifies the individual rule needed to build an object. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 QMAKE_TARGET

    Specifies the name of the project target.  The value of this
    variable is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QT

    Specifies the Qt modules that are used by your project.

    The table below shows the options that can be used with the \c QT variable
    and the Qt modules that are associated with each of them:

    \table
    \header \li Option                     \li Module Enabled
    \row    \li axcontainer                \li \l{Using ActiveX controls and COM in Qt}
                                               {QAxContainer}, which is
                                               part of the \l{Active Qt} framework
    \row    \li axserver                   \li \l{Building ActiveX servers in Qt}
                                               {QAxServer}, which is
                                               part of the \l{Active Qt} framework
    \row    \li concurrent                 \li \l{Qt Concurrent}
    \row    \li core (included by default) \li \l{Qt Core}
    \row    \li dbus                       \li \l{Qt D-Bus}
    \row    \li declarative                \li \l{Qt Quick 1} (deprecated)
    \row    \li designer                   \li \l{Qt Designer}
    \row    \li designercomponents         \li \l{Qt Designer Components}
    \row    \li gui  (included by default) \li \l{Qt GUI}
    \row    \li help                       \li \l{Qt Help}
    \row    \li multimedia                 \li \l{Qt Multimedia}
    \row    \li multimediawidgets          \li \l{Qt Multimedia Widgets}
    \row    \li network                    \li \l{Qt Network}
    \row    \li opengl                     \li \l{Qt OpenGL} (deprecated)
    \row    \li printsupport               \li \l{Qt Print Support}
    \row    \li qml                        \li \l{Qt QML}
    \row    \li qmltest                    \li \l{Qt QML Test}
    \row    \li x11extras                  \li \l{Qt X11 Extras}
    \row    \li quick                      \li \l{Qt Quick}
    \row    \li script                     \li \l{Qt Script} (deprecated)
    \row    \li scripttools                \li \l{Qt Script Tools} (deprecated)
    \row    \li sensors                    \li \l{Qt Sensors}
    \row    \li serialport                 \li \l{Qt Serial Port}
    \row    \li sql                        \li \l{Qt SQL}
    \row    \li svg                        \li \l{Qt SVG}
    \row    \li testlib                    \li \l{Qt Test}
    \row    \li uitools                    \li \l{Qt UI Tools}
    \row    \li webkit                     \li \l{Qt WebKit}
    \row    \li webkitwidgets              \li \l{Qt WebKit Widgets}
    \row    \li widgets                    \li \l{Qt Widgets}
    \row    \li winextras                  \li \l{Qt Windows Extras}
    \row    \li xml                        \li \l{Qt XML} (deprecated)
    \row    \li xmlpatterns                \li \l{Qt XML Patterns}
    \endtable

    By default, \c QT contains both \c core and \c gui, ensuring that standard
    GUI applications can be built without further configuration.

    If you want to build a project \e without the \l{Qt GUI} module, you need to
    exclude the \c gui value with the "-=" operator. The following line will
    result in a minimal Qt project being built:

    \snippet code/doc_src_qmake-manual.pro 47

    \section1 QTPLUGIN

    Specifies a list of names of static Qt plugins that are to be
    linked with an application so that they are available as built-in
    resources.

    \target QT_VERSION_variable
    \section1 QT_VERSION

    Contains the current version of Qt.

    \target QT_MAJOR_VERSION
    \section1 QT_MAJOR_VERSION

    Contains the current major version of Qt.

    \target QT_MINOR_VERSION
    \section1 QT_MINOR_VERSION

    Contains the current minor version of Qt.

    \target QT_PATCH_VERSION
    \section1 QT_PATCH_VERSION

    Contains the current patch version of Qt.

    \section1 RC_FILE

    Specifies the name of the resource file for the application.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 RC_INCLUDEPATH

    Specifies include paths that are passed to the Windows Resource Compiler.

    \target RCC_DIR
    \section1 RCC_DIR

    Specifies the directory for Qt Resource Compiler output files.

    For example:

    \snippet code/doc_src_qmake-manual.pro 48

    \target REQUIRES
    \section1 REQUIRES

    Specifies a list of values that are evaluated as conditions. If any of the conditions is false,
    qmake skips this project (and its \l{SUBDIRS}) when building.

    \note We recommend using the \l{requires(condition)}{requires()} function
    instead if you want to skip projects or subprojects when building.

    \target RESOURCES
    \section1 RESOURCES

    Specifies the name of the resource collection files (qrc)
    for the target. For more information about the resource collection
    file, see \l{The Qt Resource System}.

    \section1 RES_FILE

    Specifies the name of the compiled Windows resource file for the target.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target SIGNATURE_FILE
    \section1 SIGNATURE_FILE

    \note This variable is only used on Windows CE.

    Specifies which signature file should be used to sign the project target.

    \note This variable will overwrite the setting you have specified in configure,
    with the \c -signature option.

    \target SOURCES
    \section1 SOURCES

    Specifies the names of all source files in the project.

    For example:

    \snippet code/doc_src_qmake-manual.pro 49

    See also \l{#HEADERS}{HEADERS}.

    \target SUBDIRS
    \section1 SUBDIRS

    This variable, when used with the \c subdirs \l{#TEMPLATE}{template}
    specifies the names of all subdirectories or project files that contain
    parts of the project that need to be built. Each subdirectory specified
    using this variable must contain its own project file.

    It is recommended that the project file in each subdirectory has the same
    base name as the subdirectory itself, because that makes it possible to omit
    the file name. For example, if the subdirectory is called \c myapp, the
    project file in that directory should be called \c myapp.pro.

    Alternatively, you can specify a relative path to a .pro file in any
    directory. It is strongly recommended that you specify only paths in the
    current project's parent directory or its subdirectories.

    For example:

    \snippet code/doc_src_qmake-manual.pro 50

    If you need to ensure that the subdirectories are built in the order in
    which they are specified, update the \l{#CONFIG}{CONFIG} variable to
    include the \c ordered option:

    \snippet code/doc_src_qmake-manual.pro 51

    It is possible to modify this default behavior of \c SUBDIRS by giving
    additional modifiers to \c SUBDIRS elements. Supported modifiers are:

    \table
    \header \li Modifier \li Effect
    \row \li .subdir     \li Use the specified subdirectory instead of \c SUBDIRS value.
    \row \li .file       \li Specify the subproject \c pro file explicitly. Cannot be
                        used in conjunction with \c .subdir modifier.
    \row \li .depends    \li This subproject depends on specified subproject.
                        Available only on platforms that use makefiles.
    \row \li .makefile   \li The makefile of subproject.
                        Available only on platforms that use makefiles.
    \row \li .target     \li Base string used for makefile targets related to this
                        subproject.
                        Available only on platforms that use makefiles.
    \endtable

    For example, define two subdirectories, both of which reside in a different directory
    than the \c SUBDIRS value, and one of the subdirectories must be built before the other:

    \snippet code/doc_src_qmake-manual.pro 149

    \target TARGET
    \section1 TARGET

    Specifies the name of the target file. Contains the base name of the project
    file by default.

    For example:

    \snippet code/doc_src_qmake-manual.pro 52

    The project file above would produce an executable named \c myapp on
    unix and \c{myapp.exe} on Windows.

    \section1 TARGET_EXT

    Specifies the extension of \c TARGET. The value of this variable
    is typically handled by qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 TARGET_x

    Specifies the extension of \c TARGET with a major version number.
    The value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \section1 TARGET_x.y.z

    Specifies the extension of \c TARGET with version number. The
    value of this variable is typically handled by
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target TEMPLATE
    \section1 TEMPLATE

    Specifies the name of the template to use when generating the project. The
    allowed values are:

    \table
    \header \li Option \li Description
    \row    \li app    \li Creates a Makefile for building applications
            (the default). See \l{Building an Application} for more information.
    \row    \li lib    \li Creates a Makefile for building libraries. See
            \l{Building a Library} for more information.
    \row    \li subdirs \li Creates a Makefile for building targets in subdirectories.
            The subdirectories are specified using the \l{#SUBDIRS}{SUBDIRS}
            variable.
    \row    \li vcapp  \li Windows only. Creates an application project for
            Visual Studio. See \l{Creating Visual Studio Project Files} for more
            information.
    \row    \li vclib  \li Windows only. Creates a library project for Visual Studio.
    \endtable

    For example:

    \snippet code/doc_src_qmake-manual.pro 53

    The template can be overridden by specifying a new template type with the
    \c -t command line option. This overrides the template type \e after the .pro
    file has been processed. With .pro files that use the template type to
    determine how the project is built, it is necessary to declare TEMPLATE on
    the command line rather than use the \c -t option.

    \section1 TRANSLATIONS

    Specifies a list of translation (.ts) files that contain
    translations of the user interface text into non-native languages.

    See the \l{Qt Linguist Manual} for more information about
    internationalization (i18n) and localization (l10n) with Qt.

    \target UI_DIR
    \section1 UI_DIR

    Specifies the directory where all intermediate files from uic
    should be placed.

    For example:

    \snippet code/doc_src_qmake-manual.pro 54

    \target VERSION
    \section1 VERSION

    Specifies the version number of the application if the \c app \l{#TEMPLATE}{template} is
    specified or the version number of the library if the \c lib template is specified.

    For example:

    \snippet code/doc_src_qmake-manual.pro 57

    \section1 VER_MAJ

    Specifies the major version number of the library if the
    \c lib \l{#TEMPLATE}{template} is specified.

    \section1 VER_MIN

    Specifies the minor version number of the library if the
    \c lib \l{#TEMPLATE}{template} is specified.

    \section1 VER_PAT

    Specifies the patch version number of the library if the
    \c lib \l{#TEMPLATE}{template} is specified.

    \section1 VPATH

    Tells qmake where to search for files it cannot open. For example, if qmake
    looks for \c SOURCES and finds an entry that it cannot open, it looks
    through the entire VPATH list to see if it can find the file on its own.

    See also \l{#DEPENDPATH}{DEPENDPATH}.

    \target YACCSOURCES
    \section1 YACCSOURCES

    Specifies a list of Yacc source files to be included
    in the project. All dependencies, headers and source files will
    automatically be included in the project.

    For example:

    \snippet code/doc_src_qmake-manual.pro 58

    \section1 _PRO_FILE_

    Contains the path to the project file in use.

    For example, the following line causes the location of the project
    file to be written to the console:

    \snippet qmake/project_location.pro project file

    \note Do not attempt to overwrite the value of this variable.

    \section1 _PRO_FILE_PWD_

    Contains the path to the directory containing the project file in use.

    For example, the following line causes the location of the directory
    containing the project file to be written to the console:

    \snippet qmake/project_location.pro project file directory

    \note Do not attempt to overwrite the value of this variable.
*/

/*!
    \page qmake-function-reference.html
    \title Replace Functions
    \contentspage {qmake Manual}{Contents}
    \previouspage Variables
    \nextpage Test Functions
    \keyword qmake Function Reference - Replace Functions

    qmake provides functions for processing the contents of variables
    during the configuration process. These functions are called
    \e {replace functions}. Typically, they return values that you can
    assign to other variables. You can obtain these values by prefixing a
    function with the \c $$ operator. Replace functions can be divided into
    built-in functions and function libraries.

    See also \l{Test Functions}.

    \section1 Built-in Replace Functions

    Basic replace functions are implemented as built-in functions.

    \section2 absolute_path(path[, base])

    Returns the absolute path of \c path.

    If \c base is not specified, uses the current directory as the base
    directory.

    For example, the following call returns the string
    \c {"/home/johndoe/myproject/readme.txt"}:

    \snippet code/doc_src_qmake-manual.pro 159

    See also \l{clean_path(path)}{clean_path()},
    \l{relative_path(filePath[, base])}{relative_path()}.

    \section2 basename(variablename)

    Returns the basename of the file specified in \c variablename.

    For example:

    \snippet code/doc_src_qmake-manual.pro 59

    \section2 cat(filename[, mode])

    Returns the contents of \c filename. You can specify the following options
    for \c mode:

    \list
        \li \c blob returns the entire contents of the file as one value
        \li \c lines returns each line as a separate value (without line
            endings)
        \li \c true (default value) and \c false return file contents as
            separate values, split according to qmake value list splitting rules
            (as in variable assignments). If \c mode is \c false, values that
            contain only a newline character are inserted into the list to
            indicate where line breaks were in the file.
    \endlist

    \section2 clean_path(path)

    Returns \c path with directory separators normalized (converted to "/") and
    redundant ones removed, and "."s and ".."s resolved (as far as possible).
    This function is a wrapper around QDir::cleanPath.

    See also \l{absolute_path(path[, base])}{absolute_path()},
    \l{relative_path(filePath[, base])}{relative_path()},
    \l{shell_path(path)}{shell_path()}, \l{system_path(path)}{system_path()}.

    \section2 dirname(file)

    Returns the directory name part of the specified file. For example:

    \snippet qmake/dirname.pro 0

    \section2 enumerate_vars

    Returns a list of all defined variable names.

    \section2 escape_expand(arg1 [, arg2 ..., argn])

    Accepts an arbitrary number of arguments. It expands the
    escape sequences \c {\n}, \c {\r}, \c {\t} for each argument and returns
    the arguments as a list.

    \note If you specify the string to expand literally, you need to escape the
    backslashes, as illustrated by the following code snippet:

    \snippet code/doc_src_qmake-manual.pro 173

    \target findfunction
    \section2 find(variablename, substr)

    Returns all the values in \c variablename that match the regular expression
    \c substr.

    \snippet code/doc_src_qmake-manual.pro 64

    MY_VAR2 will contain '-Lone -Ltwo -Lthree -Lfour -Lfive', and MY_VAR3 will
    contain 'three two three'.

    \section2 first(variablename)

    Returns the first value of \c variablename.

    For example, the following call returns \c firstname:

    \snippet code/doc_src_qmake-manual.pro 161

    See also \l{last(variablename)}{last()}.

    \section2 format_number(number[, options...])

    Returns \c number in the format specified by \c options. You can specify the
    following options:

    \list
        \li \c ibase=n sets the base of the input to \c n
        \li \c obase=n sets the base of the output to \c n
        \li \c width=n sets the minimum width of the output to \c n. If the
            output is shorter than \c width, it is padded with spaces
        \li \c zeropad pads the output with zeroes instead of spaces
        \li \c padsign prepends a space to positive values in the output
        \li \c alwayssign prepends a plus sign to positive values in the output
        \li \c leftalign places the padding to the right of the value in the
            output
    \endlist

    Floating-point numbers are currently not supported.

    For example, the following call converts the hexadecimal number \c BAD to
    \c 002989:

    \snippet code/doc_src_qmake-manual.pro 163

    \section2 fromfile(filename, variablename)

    Evaluates \c filename as a qmake project file and returns the value assigned
    to \c variablename.

    See also \l{infile(filename, var, val)}{infile()}.

    \section2 join(variablename, glue, before, after)

    Joins the value of \c variablename with \c glue. If this value is
    not empty, this function prefixes the value with \c before and suffixes it
    with \c after. \c variablename is the only required field, the others default
    to empty strings. If you need to encode spaces in \c glue, \c before, or \c
    after, you must quote them.

    \section2 last(variablename)

    Returns the last value of \c variablename.

    For example, the following call returns \c phone:

    \snippet code/doc_src_qmake-manual.pro 162

    See also \l{first(variablename)}{first()}.

    \section2 list(arg1 [, arg2 ..., argn])

    Takes an arbitrary number of arguments. It creates a uniquely
    named variable that contains a list of the arguments, and returns the name
    of that variable. You can use the variable to write a loop as illustrated by
    the following code snippet

    \snippet code/doc_src_qmake-manual.pro 170

    instead of:

    \snippet code/doc_src_qmake-manual.pro 171

    \section2 lower(arg1 [, arg2 ..., argn])

    Takes an arbitrary number of arguments and converts them to lower case.

    See also \l{upper(arg1 [, arg2 ..., argn])}{upper()}.

    \section2 member(variablename, position)

    Returns the value at the given \c position in the list of items in
    \c variablename.
    If an item cannot be found at the position specified, an empty string is
    returned. \c variablename is the only required field. If not specified,
    \c position defaults to 0, causing the first value in the list to be
    returned.

    \section2 prompt(question)

    Displays the specified \c question, and returns a value read from stdin.

    \section2 quote(string)

    Converts a whole \c string into a single entity and returns the result.
    This is just a fancy way of enclosing the string into double quotes.

    \section2 re_escape(string)

    Returns the \c string with every special regular expression character
    escaped with a backslash. This function is a wrapper around QRegExp::escape.

    \section2 relative_path(filePath[, base])

    Returns the path to \c filePath relative to \c base. If \c base is not
    specified, it is the current project directory. This function is a wrapper
    around QDir::relativeFilePath.

    See also \l{absolute_path(path[, base])}{absolute_path()},
    \l{clean_path(path)}{clean_path()}.

    \section2 replace(string, old_string, new_string)

    Replaces each instance of \c old_string with \c new_string in the
    contents of the variable supplied as \c string. For example, the
    code

    \snippet qmake/replace.pro 0

    prints the message:

    \snippet code/doc_src_qmake-manual.pro 70

    \section2 sprintf(string, arguments...)

    Replaces %1-%9 with the arguments passed in the comma-separated list
    of function \c arguments and returns the processed string.

    \section2 resolve_depends(variablename, prefix)

    This is an internal function that you will typically not need.

    \section2 reverse(variablename)

    Returns the values of \c variablename in reverse order.

    \section2 section(variablename, separator, begin, end)

    Returns a section of the value of \c variablename. This function is a
    wrapper around QString::section.

    For example, the following call outputs \c surname:

    \snippet code/doc_src_qmake-manual.pro 167

    \section2 shadowed(path)

    Maps the path from the project source directory to the build directory.
    This function returns \c path for in-source builds. It returns an empty
    string if \c path points outside of the source tree.

    \section2 shell_path(path)

    Converts all directory separators within \c path to separators that are
    compatible with the shell that is used while building the project (that is,
    the shell that is invoked by the make tool). For example, slashes are
    converted to backslashes when the Windows shell is used.

    See also \l{system_path(path)}{system_path()}.

    \section2 shell_quote(arg)

    Quotes \c arg for the shell that is used while building the project.

    See also \l{system_quote(arg)}{system_quote()}.

    \section2 size(variablename)

    Returns the number of values of \c variablename.

    \section2 sort_depends(variablename, prefix)

    This is an internal function that you will typically not need.

    \section2 split(variablename, separator)

    Splits the value of \c variablename into separate values, and returns them
    as a list. This function is a wrapper around QString::split.

    For example:

    \snippet code/doc_src_qmake-manual.pro 168

    \section2 system(command[, mode])

    You can use this variant of the \c system function to obtain stdout from the
    command and assign it to a variable.

    For example:

    \snippet code/doc_src_qmake-manual.pro 72

    See also the test variant of \l{system(command)}{system()}.

    \section2 system_path(path)

    Converts all directory separators within \c path to separators that are
    compatible with the shell that is used by the \c{system()} functions to
    invoke commands. For example, slashes are converted to backslashes for the
    Windows shell.

    See also \l{shell_path(path)}{shell_path()}.

    \section2 system_quote(arg)

    Quotes \c arg for the for the shell that is used by the \c{system()}
    functions.

    See also \l{shell_quote(arg)}{shell_quote()}.

    \target unique
    \section2 unique(variablename)

    Returns the list of values in \c variablename with duplicate entries removed.
    For example:

    \snippet code/doc_src_qmake-manual.pro 73

    \section2 upper(arg1 [, arg2 ..., argn])

    Takes an arbitrary number of arguments and converts them to upper case.

    See also \l{lower(arg1 [, arg2 ..., argn])}{lower()}.

    \section2 val_escape(variablename)

    Escapes the values of \c variablename in a way that enables parsing them as
    qmake code.
*/

/*!
    \page qmake-test-function-reference.html
    \title Test Functions
    \contentspage {qmake Manual}{Contents}
    \previouspage Replace Functions
    \keyword qmake Function Reference - Test Functions

    Test functions return a boolean value that you can test for in the
    conditional parts of scopes. Test functions can be divided into
    built-in functions and function libraries.

    See also \l{Replace Functions}.

    \section1 Built-in Test Functions

    Basic test functions are implemented as built-in functions.

    \section2 cache(variablename, [set|add|sub] [transient] [super|stash], [source variablename])

    This is an internal function that you will typically not need.

    \section2 CONFIG(config)

    This function can be used to test for variables placed into the
    \l{CONFIG} variable. This is the same as scopes,
    but has the added advantage that a second parameter can be passed to test for
    the active config. As the order of values is important in \c CONFIG
    variables (that is, the last one set will be considered the active config for
    mutually exclusive values) a second parameter can be used to specify a set
    of values to consider. For example:

    \snippet code/doc_src_qmake-manual.pro 60

    Because release is considered the active setting (for feature parsing)
    it will be the CONFIG used to generate the build file. In the common
    case a second parameter is not needed, but for specific mutual
    exclusive tests it is invaluable.

    \section2 contains(variablename, value)

    Succeeds if the variable \c variablename contains the value \c value;
    otherwise fails. It is possible to specify a regular expression for
    parameter \e value.

    You can check the return value of this function using a scope.

    For example:

    \snippet code/doc_src_qmake-manual.pro 61

    The contents of the scope are only processed if the \c drivers
    variable contains the value \c network. If this is the case, the
    appropriate files are added to the \l{SOURCES} and \l{HEADERS}
    variables.

    \target countfunction
    \section2 count(variablename, number)

    Succeeds if the variable \c variablename contains a list with the
    specified \c number of values; otherwise fails.

    This function is used to ensure that declarations inside a scope are
    only processed if the variable contains the correct number of values.
    For example:

    \snippet qmake/functions.pro 2

    \section2 debug(level, message)

    Checks whether qmake runs at the specified debug level. If yes, it returns
    true and prints a debug message.

    \section2 defined(name[, type])

    Tests whether the function or variable \c name is defined. If \c type is
    omitted, checks all functions. To check only variables or particular type of
    functions, specify \c type. It can have the following values:

    \list
        \li \c test only checks test functions
        \li \c replace only checks replace functions
        \li \c var only checks variables
    \endlist

    \section2 equals(variablename, value)

    Tests whether \c variablename equals the string \c value.

    For example:

    \snippet code/doc_src_qmake-manual.pro 160

    \section2 error(string)

    This function never returns a value. qmake displays \c string as an error
    message to the user and exits. This function should only be used for
    unrecoverable errors.

    For example:

    \snippet code/doc_src_qmake-manual.pro 62

    \section2 eval(string)

    Evaluates the contents of the string using
    qmake syntax rules and returns true.
    Definitions and assignments can be used in the string to modify the
    values of existing variables or create new definitions.

    For example:
    \snippet qmake/functions.pro 4

    \note Quotation marks can be used to delimit the string, and
    the return value can be discarded if it is not needed.

    \section2 exists(filename)

    Tests whether a file with the given \c filename exists.
    If the file exists, the function succeeds; otherwise it fails.
    If a regular expression is specified for the filename, this function
    succeeds if any file matches the regular expression specified.

    For example:
    \snippet code/doc_src_qmake-manual.pro 63

    \note "/" should be used as a directory separator, regardless of the
    platform in use.

    \section2 export(variablename)

    Exports the current value of \c variablename from the local context of a
    function to the global context.

    \section2 files(pattern[, recursive=false])

    Expands the specified wildcard pattern and returns a list of filenames.
    If \c recursive is true, this function descends into subdirectories.

    \target forfunction
    \section2 for(iterate, list)

    Starts a loop that iterates over all values in \c list, setting \c iterate to each
    value in turn. As a convenience, if \c list is 1..10 then iterate will
    iterate over the values 1 through 10.

    For example:

    \snippet code/doc_src_qmake-manual.pro 65

    \section2 greaterThan(variablename, value)

    Tests that the value of \c variablename is greater than \c value. First,
    this function attempts a numerical comparison. If at least one of the
    operands fails to convert, this function does a string comparison.

    For example:

    \snippet code/doc_src_qmake-manual.pro 164

    It is impossible to compare two numbers as strings directly. As a
    workaround, construct temporary values with a non-numeric prefix and compare
    these.

    For example:

    \snippet code/doc_src_qmake-manual.pro 172

    See also \l{lessThan(variablename, value)}{lessThan()}.

    \section2 if(condition)

    Evaluates \c condition. It is used to group boolean expressions.

    For example:

    \snippet code/doc_src_qmake-manual.pro 166

    \section2 include(filename)

    Includes the contents of the file specified by \c filename into the
    current project at the point where it is included. This function
    succeeds if \c filename is included; otherwise it fails. The included
    file is processed immediately.

    You can check whether the file was included by using this function as
    the condition for a scope. For example:

    \snippet code/doc_src_qmake-manual.pro 66

    \section2 infile(filename, var, val)

    Succeeds if the file \c filename (when parsed by qmake itself) contains the
    variable \c var with a value of \c val; otherwise fails. If you do not
    specify \c val, the function tests whether \c var has been assigned in
    the file.

    \section2 isActiveConfig

    This is an alias for the \c CONFIG function.

    \section2 isEmpty(variablename)

    Succeeds if the variable \c variablename is empty; otherwise fails.
    This is the equivalent of \c{count( variablename, 0 )}.

    For example:

    \snippet code/doc_src_qmake-manual.pro 67

    \section2 isEqual

    This is an alias for the \c equals function.

    \section2 lessThan(variablename, value)

    Tests that the value of \c variablename is less than \c value. Works as
    \l{greaterThan(variablename, value)}{greaterThan()}.

    For example:

    \snippet code/doc_src_qmake-manual.pro 165

    \section2 load(feature)

    Loads the feature file (\c .prf) specified by \c feature,
    unless the feature has already been loaded.

    \section2 log(message)

    Prints a message on the console. Unlike the \c message function, neither
    prepends text nor appends a line break.

    See also \l{message(string)}{message()}.

    \section2 message(string)

    Always succeeds, and displays \c string as a general message to the user.
    Unlike the \c error() function, this function allows processing to continue.

    \snippet code/doc_src_qmake-manual.pro 68

    The above line causes "This is a message" to be written to the console.
    The use of quotation marks is optional, but recommended.

    \note By default, messages are written out for each Makefile generated by
    qmake for a given project. If you want to ensure that messages only appear
    once for each project, test the \c build_pass variable
    \l{Scopes}{in conjunction with a scope} to filter out
    messages during builds. For example:

    \snippet code/doc_src_qmake-manual.pro 69

    \section2 mkpath(dirPath)

    Creates the directory path \c dirPath. This function is a wrapper around the
    QDir::makepath function.

    \section2 requires(condition)

    Evaluates \c condition. If the condition is false, qmake skips this
    project (and its \l{SUBDIRS}) when building.

    \note You can also use the \l{REQUIRES} variable for this purpose. However, we
    recommend using this function, instead.

    \section2 system(command)

    Executes the given \c command in a secondary shell. Succeeds
    if the command returns with a zero exit status; otherwise fails.
    You can check the return value of this function using a scope.

    For example:

    \snippet code/doc_src_qmake-manual.pro 71

    See also the replace variant of \l{system(command[, mode])}{system()}.

    \target touchfunction
    \section2 touch(filename, reference_filename)

    Updates the time stamp of \c filename to match the time stamp of
    \c reference_filename.

    \section2 unset(variablename)

    Removes \c variablename from the current context.

    For example:

    \snippet code/doc_src_qmake-manual.pro 169

    \section2 warning(string)

    Always succeeds, and displays \c string as a warning message to the user.

    \section2 write_file(filename, [variablename, [mode]])

    Writes the values of \c variablename to a file with the name \c filename,
    each value on a separate line. If \c variablename is not specified, creates
    an empty file. If \c mode is \c append and the file already exists, appends
    to it instead of replacing it.

    \section1 Test Function Library

    Complex test functions are implemented in a library of .prf files.

    \section2 packagesExist(packages)

    Uses the PKGCONFIG mechanism to determine whether or not the given packages
    exist at the time of project parsing.

    This can be useful to optionally enable or disable features. For example:

    \snippet code/doc_src_qmake-manual.pro 157

    And then, in the code:

    \snippet code/doc_src_qmake-manual.pro 158

    \section2 prepareRecursiveTarget(target)

    Facilitates the creation of project-wide targets similar to the \c install
    target by preparing a target that iterates through all subdirectories. For
    example:

    \snippet code/doc_src_qmake-manual.pro 174

    Subdirs that have \c have_no_default or \c no_<target>_target specified in
    their .CONFIG are excluded from this target:

    \snippet code/doc_src_qmake-manual.pro 175

    You must add the prepared target manually to \l{QMAKE_EXTRA_TARGETS}:

    \snippet code/doc_src_qmake-manual.pro 176

    To make the target global, the code above needs to be included into every
    subdirs subproject. In addition, to make these targets do anything,
    non-subdirs subprojects need to include respective code. The easiest way to
    achieve this is creating a custom feature file. For example:

    \snippet code/doc_src_qmake-manual.pro 177

    The feature file needs to be injected into each subproject, for example by
    .qmake.conf:

    \snippet code/doc_src_qmake-manual.pro 178

    \section2 qtCompileTest(test)

    Builds a test project. If the test passes, true is returned and
    \c {config_<test>} is added to the \l{CONFIG} variable. Otherwise, false is
    returned.

    To make this function available, you need to load the respective feature
    file:

    \snippet code/doc_src_qmake-manual.pro 179

    This also sets the variable QMAKE_CONFIG_TESTS_DIR to the
    \c config.tests subdirectory of the project's parent directory.
    It is possible to override this value after loading the feature file.

    Inside the tests directory, there has to be one subdirectory per test that
    contains a simple qmake project. The following code snippet illustrates the
    .pro file of the project:

    \snippet code/doc_src_qmake-manual.pro 180

    The following code snippet illustrates the main .cpp file of the project:

    \snippet code/doc_src_qmake-manual.pro 181

    The following code snippet shows the invocation of the test:

    \snippet code/doc_src_qmake-manual.pro 182

    If the test project is built successfully, the test passes.

    The test results are automatically cached, which also makes them
    available to all subprojects. It is therefore recommended to run
    all configuration tests in the top-level project file.

    To suppress the re-use of cached results, pass \c{CONFIG+=recheck}
    to qmake.

    See also \l{load(feature)}{load()}.

    \section2 qtHaveModule(name)

    Checks whether the Qt module specified by \c name is present.
    For a list of possible values, see \l{Variables#QT}{QT}.
*/

/*!
    \page qmake-environment-reference.html
    \contentspage {qmake Manual}{Contents}
    \previouspage Using Precompiled Headers
    \nextpage Reference

    \title Configuring qmake

    \section1 Properties

    qmake has a system for persistent configuration, which allows you to set a
    property in qmake once, and query it each time qmake is invoked. You can set
    a property in qmake as follows:

    \snippet code/doc_src_qmake-manual.pro 74

    The appropriate property and value should be substituted for
    \c PROPERTY and \c VALUE.

    You can retrieve this information back from qmake as follows:

    \snippet code/doc_src_qmake-manual.pro 75

    \note \c{qmake -query} lists built-in properties in addition to the
    properties that you set with \c{qmake -set PROPERTY VALUE}.

    This information will be saved into a QSettings object (meaning it
    will be stored in different places for different platforms).

    The following list summarizes the \c built-in properties:

    \list
        \li QMAKE_SPEC - the shortname of the host \c mkspec that is resolved
            and stored in the \l{QMAKESPEC} variable during a host build
        \li QMAKE_VERSION - the current version of qmake
        \li QMAKE_XSPEC - the shortname of the target \c mkspec that is resolved
            and stored in the \l{QMAKESPEC} variable during a target build
        \li QT_HOST_BINS - location of host executables
        \li QT_HOST_DATA - location of data for host executables used by qmake
        \li QT_HOST_PREFIX - default prefix for all host paths
        \li QT_INSTALL_ARCHDATA - location of general architecture-dependent Qt
            data
        \li QT_INSTALL_BINS - location of Qt binaries (tools and applications)
        \li QT_INSTALL_CONFIGURATION - location for Qt settings. Not applicable
            on Windows
        \li QT_INSTALL_DATA - location of general architecture-independent Qt
            data
        \li QT_INSTALL_DOCS - location of documentation
        \li QT_INSTALL_EXAMPLES - location of examples
        \li QT_INSTALL_HEADERS - location for all header files
        \li QT_INSTALL_IMPORTS - location of QML 1.x extensions
        \li QT_INSTALL_LIBEXECS - location of executables required by libraries at runtime
        \li QT_INSTALL_LIBS - location of libraries
        \li QT_INSTALL_PLUGINS - location of Qt plugins
        \li QT_INSTALL_PREFIX - default prefix for all paths
        \li QT_INSTALL_QML - location of QML 2.x extensions
        \li QT_INSTALL_TESTS - location of Qt test cases
        \li QT_INSTALL_TRANSLATIONS - location of translation information for
            Qt strings
        \li QT_SYSROOT - the sysroot used by the target build environment
        \li QT_VERSION - the Qt version. We recommend that you query Qt module specific
            version numbers by using $$QT.<module>.version variables instead.
    \endlist

    For example, you can query the installation of Qt for this version of qmake with the
    \c QT_INSTALL_PREFIX property:

    \snippet code/doc_src_qmake-manual.pro 77

    You can query the values of properties in a project file as follows:

    \snippet code/doc_src_qmake-manual.pro 78

    \target QMAKESPEC
    \section1 QMAKESPEC

    qmake requires a platform and compiler
    description file which contains many default values used to generate
    appropriate Makefiles. The standard Qt distribution comes with many of
    these files, located in the \c mkspecs subdirectory of the Qt installation.

    The \c QMAKESPEC environment variable can contain any of the following:

    \list
    \li A complete path to a directory containing a \c{qmake.conf} file.
       In this case qmake will open the
       \c{qmake.conf} file from within that directory. If the file does not
       exist, qmake will exit with an error.
    \li The name of a platform-compiler combination. In this case,
       qmake will search in the directory specified
       by the \c mkspecs subdirectory of the data path specified when Qt was
       compiled (see QLibraryInfo::DataPath).
    \endlist

    \note The \c QMAKESPEC path will automatically be added to the
    \l{INCLUDEPATH} system variable.

    \target cache
    \section1 Cache File

    The cache file is a special file qmake reads to
    find settings not specified in the \c qmake.conf file, project files, or
    at the command line. When qmake is run, it looks for a file called
    \c{.qmake.cache} in parent directories of the current directory, unless you
    specify \c -nocache. If qmake
    fails to find this file, it will silently ignore this step of processing.

    If qmake  finds a \c{.qmake.cache} file then it will process this file first before
    it processes the project file.

    \target Extensions
    \section1 File Extensions

    Under normal circumstances qmake will try to
    use appropriate file extensions for your platform. However, it is
    sometimes necessary to override the default choices for each platform and
    explicitly define file extensions for qmake to
    use. This is achieved by redefining certain built-in variables. For
    example, the extension used for \l moc files can be redefined with the
    following assignment in a project file:

    \snippet code/doc_src_qmake-manual.pro 85

    The following variables can be used to redefine common file extensions recognized
    by qmake:

    \list
    \li \l{QMAKE_EXT_MOC} modifies the extension placed on included moc files.
    \li \l{QMAKE_EXT_UI} modifies the extension used for \QD UI files
        (usually in \l{FORMS}).
    \li \l{QMAKE_EXT_PRL} modifies the extension placed on
                       \l{#LibDepend}{library dependency files}.
    \li \l{QMAKE_EXT_LEX} changes the suffix used in Lex files (usually in
        \l{LEXSOURCES}).
    \li \l{QMAKE_EXT_YACC} changes the suffix used in Yacc files (usually in
        \l{YACCSOURCES}).
    \li \l{QMAKE_EXT_OBJ} changes the suffix used on generated object files.
    \endlist

    All of the above accept just the first value, so you must assign to it just one
    value that will be used throughout your project file. There are two variables that
    accept a list of values:

    \list
    \li \l{QMAKE_EXT_CPP} causes qmake to interpret
        all files with these suffixes as C++ source files.
    \li \l{QMAKE_EXT_H} causes qmake to interpret
        all files with these suffixes as C and C++ header files.
    \endlist
*/

/*!
    \page qmake-language.html
    \title qmake Language
    \contentspage {qmake Manual}{Contents}
    \previouspage Platform Notes
    \nextpage Advanced Usage

    Many qmake project files simply describe the
    sources and header files used by the project, using a list of
    \c{name = value} and \c{name += value} definitions.
    qmake also provides other operators, functions,
    and scopes that can be used to process the information supplied in
    variable declarations. These advanced features allow Makefiles to be
    generated for multiple platforms from a single project file.

    \section1 Operators

    In many project files, the assignment (\c{=}) and append (\c{+=}) operators can
    be used to include all the information about a project. The typical pattern of
    use is to assign a list of values to a variable, and append more values
    depending on the result of various tests. Since
    qmake defines certain variables using default
    values, it is sometimes necessary to use the removal (\c{-=}) operator to
    filter out values that are not required. The following sections describe how
    to use operators to manipulate the contents of variables.

    \section2 Assigning Values

    The \c = operator assigns a value to a variable:

    \snippet code/doc_src_qmake-manual.pro 89

    The above line sets the \l{TARGET} variable to \c myapp. This will overwrite any
    values previously set for \c TARGET with \c myapp.

    \section2 Appending Values

    The \c += operator appends a new value to the list of values in a variable:

    \snippet code/doc_src_qmake-manual.pro 90

    The above line appends \c USE_MY_STUFF to the list of pre-processor defines to be put
    in the generated Makefile.

    \section2 Removing Values

    The \c -= operator removes a value from the list of values in a variable:

    \snippet code/doc_src_qmake-manual.pro 91

    The above line removes \c USE_MY_STUFF from the list of pre-processor defines to be
    put in the generated Makefile.

    \section2 Adding Unique Values

    The \c *= operator adds a value to the list of values in a variable, but only
    if it is not already present. This prevents values from being included many
    times in a variable. For example:

    \snippet code/doc_src_qmake-manual.pro 92

    In the above line, \c USE_MY_STUFF will only be added to the list of pre-processor
    defines if it is not already defined. Note that the \l{unique}{unique()}
    function can also be used to ensure that a variable only contains one
    instance of each value.

    \section2 Replacing Values

    The \c ~= operator replaces any values that match a regular expression with
    the specified value:

    \snippet code/doc_src_qmake-manual.pro 93

    In the above line, any values in the list that start with \c QT_D or \c QT_T are
    replaced with \c QT.

    \section2 Variable Expansion

    The \c $$ operator is used to extract the contents of a variable, and can be
    used to pass values between variables or supply them to functions:

    \snippet code/doc_src_qmake-manual.pro 94

    Variables can be used to store the contents of environment variables.
    These can be evaluated at the time when qmake
    is run, or included in the generated Makefile for evaluation when the
    project is built.

    To obtain the contents of an environment value when
    qmake is run, use the \c $$(...) operator:

    \snippet qmake/environment.pro 0

    In the above assignment, the value of the \c PWD environment variable
    is read when the project file is processed.

    To obtain the contents of an environment value at the time when the
    generated Makefile is processed, use the \c $(...) operator:

    \snippet qmake/environment.pro 1

    In the above assignment, the value of \c PWD is read immediately
    when the project file is processed, but \c $(PWD) is assigned to
    \c DESTDIR in the generated Makefile. This makes the build process
    more flexible as long as the environment variable is set correctly
    when the Makefile is processed.

    \section2 Accessing qmake Properties

    The special \c $$[...] operator can be used to access qmake properties:

    \snippet qmake/qtconfiguration.pro 0

    For more information, see \l{Configuring qmake}.

    The properties accessible with this operator are typically used to
    enable third party plugins and components to be integrated in Qt.
    For example, a \QD plugin can be installed alongside \QD's built-in
    plugins if the following declaration is made in its project file:

    \snippet code/doc_src_qmake-manual.pro 101

    \target Scopes
    \section1 Scopes

    Scopes are similar to \c if statements in procedural programming languages.
    If a certain condition is true, the declarations inside the scope are processed.

    \section2 Scope Syntax

    Scopes consist of a condition followed by an opening brace on the same line,
    a sequence of commands and definitions, and a closing brace on a new line:

    \snippet qmake/scopes.pro syntax

    The opening brace \e{must be written on the same line as the condition}.
    Scopes may be concatenated to include more than one condition, as described
    in the following sections.

    \section2 Scopes and Conditions

    A scope is written as a condition followed by a series of declarations
    contained within a pair of braces. For example:

    \snippet qmake/scopes.pro 0

    The above code will add the \c paintwidget_win.cpp file to the sources listed
    in the generated Makefile when building for a Windows platform. When
    building for other platforms, the define will be ignored.

    The conditions used in a given scope can also be negated to provide an
    alternative set of declarations that will be processed only if the
    original condition is false. For example, to process something when building
    for all platforms \e except Windows, negate the scope like this:

    \snippet qmake/scopes.pro 1

    Scopes can be nested to combine more than one condition. For instance, to
    include a particular file for a certain platform only if
    debugging is enabled, write the following:

    \snippet qmake/scopes.pro 2

    To save writing many nested scopes, you can nest scopes using the \c :
    operator. The nested scopes in the above example can be rewritten in
    the following way:

    \snippet qmake/scopes.pro 3

    You may also use the \c : operator to perform single line conditional
    assignments. For example:

    \snippet code/doc_src_qmake-manual.pro 95

    The above line adds \c USE_MY_STUFF to the \l{DEFINES} variable only when
    building for the Windows platform.
    Generally, the \c : operator behaves like a logical AND operator, joining
    together a number of conditions, and requiring all of them to be true.

    There is also the \c | operator to act like a logical OR operator, joining
    together a number of conditions, and requiring only one of them to be true.

    \snippet qmake/scopes.pro 4

    You can also provide alternative declarations to those within a scope by
    using an \c else scope. Each \c else scope is processed if the conditions
    for the preceding scopes are false.
    This allows you to write complex tests when combined with other scopes
    (separated by the \c : operator as above). For example:

    \snippet code/doc_src_qmake-manual.pro 96

    \section2 Configuration and Scopes

    The values stored in the \l{CONFIG} variable are
    treated specially by qmake. Each of the possible
    values can be used as the condition for a scope. For example, the list of
    values held by \c CONFIG can be extended with the \c opengl value:

    \snippet qmake/configscopes.pro 0

    As a result of this operation, any scopes that test for \c opengl will
    be processed. We can use this feature to give the final executable an
    appropriate name:

    \snippet qmake/configscopes.pro 1
    \snippet qmake/configscopes.pro 2
    \snippet qmake/configscopes.pro 3

    This feature makes it easy to change the configuration for a project
    without losing all the custom settings that might be needed for a specific
    configuration. In the above code, the declarations in the first scope are
    processed, and the final executable will be called \c application-gl.
    However, if \c opengl is not specified, the declarations in the second
    scope are processed instead, and the final executable will be called
    \c application.

    Since it is possible to put your own values on the \c CONFIG
    line, this provides you with a convenient way to customize project files
    and fine-tune the generated Makefiles.

    \section2 Platform Scope Values

    In addition to the \c win32, \c macx, and \c unix values used in many
    scope conditions, various other built-in platform and compiler-specific
    values can be tested with scopes. These are based on platform
    specifications provided in Qt's \c mkspecs directory. For example, the
    following lines from a project file show the current specification in
    use and test for the \c linux-g++ specification:

    \snippet qmake/specifications.pro 0

    You can test for any other platform-compiler combination as long as a
    specification exists for it in the \c mkspecs directory.

    \target UsingVariables
    \section1 Variables

    Many of the variables used in project files are special variables that
    qmake uses when generating Makefiles, such as \l{DEFINES}, \l{SOURCES}, and
    \l{HEADERS}. In addition, you can create variables for your own use. qmake
    creates new
    variables with a given name when it encounters an assignment to that name.
    For example:

    \snippet code/doc_src_qmake-manual.pro 97

    There are no restricitions on what you do to your own variables, as
    qmake will ignore them unless it needs to evaluate them when processing
    a scope.

    You can also assign the value of a current variable to another
    variable by prefixing $$ to the variable name. For example:

    \snippet code/doc_src_qmake-manual.pro 98

    Now the MY_DEFINES variable contains what is in the DEFINES variable at
    this point in the project file.  This is also equivalent to:

    \snippet code/doc_src_qmake-manual.pro 99

    The second notation allows you to append the contents of the variable to
    another value without separating the two with a space. For example, the
    following will ensure that the final executable will be given a name
    that includes the project template being used:

    \snippet code/doc_src_qmake-manual.pro 100

    \target UsingReplaceFunctions
    \section1 Replace Functions

    qmake provides a selection of built-in
    functions to allow the contents of variables to be processed. These
    functions process the arguments supplied to them and return a value, or
    list of values, as a result. To assign a result to a variable, use the \c $$
    operator with this type of function as you would to assign contents of one
    variable to another:

    \snippet qmake/functions.pro 1

    This type of function should be used on the right-hand side of
    assignments (that is, as an operand).

    You can define your own functions for processing the contents of variables
    as follows:

    \snippet code/doc_src_qmake-manual.pro 102

    The following example function takes a variable name as its only
    argument, extracts a list of values from the variable with the
    \l{eval(string)}{eval()} built-in function, and compiles a list of files:

    \snippet qmake/replacefunction.pro 0

    \target UsingTestFunctions
    \section1 Test Functions

    qmake provides built-in functions that can be
    used as conditions when writing scopes. These functions do not return a
    value, but instead indicate \e success or \e failure:

    \snippet qmake/functions.pro 3

    This type of function should be used in conditional expressions
    only.

    It is possible to define your own functions to provide conditions
    for scopes. The following example tests whether each file in a list
    exists and returns true if they all exist, or false if not:

    \snippet qmake/testfunction.pro 0
*/

/*!
    \page qmake-advanced-usage.html
    \title Advanced Usage
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Language
    \nextpage Using Precompiled Headers

    \section1 Adding New Configuration Features

    qmake lets you create your own \c features that
    can be included in project files by adding their names to the list of
    values specified by the \l{CONFIG} variable. Features are collections of
    custom functions and definitions in \c{.prf} files that can reside in one
    of many standard directories. The locations of these directories are
    defined in a number of places, and qmake checks
    each of them in the following order when it looks for \c{.prf} files:

    \omit
        TODO: Fix the list, as it is incomplete and partly incorrect.
    \endomit

    \list 1
    \li In a directory listed in the \c QMAKEFEATURES environment variable that
        contains a colon-separated list of directories.
    \li In a directory listed in the \c QMAKEFEATURES property variable that
       contains a colon-spearated list of directories.
    \omit
    \li In a features directory beneath the project's root directory (where
       the \c{.qmake.cache} file is generated).
    \endomit
    \li In a features directory residing within a \c mkspecs directory.
       \c mkspecs directories can be located beneath any of the directories
       listed in the \c QMAKEPATH environment variable that contains a
        colon-separated list of directories. For example:
        \c{$QMAKEPATH/mkspecs/<features>}.
    \li In a features directory residing beneath the directory provided by the
       \l{QMAKESPEC} environment variable. For example: \c{$QMAKESPEC/<features>}.
    \li In a features directory residing in the \c data_install/mkspecs directory.
       For example: \c{data_install/mkspecs/<features>}.
    \li In a features directory that exists as a sibling of the directory
       specified by the \c QMAKESPEC environment variable.
       For example: \c{$QMAKESPEC/../<features>}.
    \endlist

    The following features directories are searched for features files:

    \list 1
    \li \c{features/unix}, \c{features/win32}, or \c{features/macx}, depending on
       the platform in use
    \li \c features/
    \endlist

    For example, consider the following assignment in a project file:

    \snippet code/doc_src_qmake-manual.pro 103

    With this addition to the \c CONFIG variable,
    qmake will search the locations listed above for
    the \c myfeatures.prf file after it has finished parsing your project file.
    On Unix systems, it will look for the following file:

    \list 1
    \li \c $QMAKEFEATURES/myfeatures.prf (for each directory listed in the
       \c QMAKEFEATURES environment variable)
    \li \c $$QMAKEFEATURES/myfeatures.prf (for each directory listed in the
       \c QMAKEFEATURES property variable)
    \li \c myfeatures.prf (in the project's root directory)
    \li \c $QMAKEPATH/mkspecs/features/unix/myfeatures.prf and
       \c $QMAKEPATH/mkspecs/features/myfeatures.prf (for each directory
       listed in the \c QMAKEPATH environment variable)
    \li \c $QMAKESPEC/features/unix/myfeatures.prf and
       \c $QMAKESPEC/features/myfeatures.prf
    \li \c data_install/mkspecs/features/unix/myfeatures.prf and
       \c data_install/mkspecs/features/myfeatures.prf
    \li \c $QMAKESPEC/../features/unix/myfeatures.prf and
       \c $QMAKESPEC/../features/myfeatures.prf
    \endlist

    \note The \c{.prf} files must have names in lower case.

    \section1 Installing Files

    It is common on Unix to also use the build tool to install applications
    and libraries; for example, by invoking \c{make install}. For this reason,
    qmake has the concept of an \c {install set}, an
    object which contains instructions about the way a part of a project is to
    be installed. For example, a collection of documentation files can be
    described in the following way:

    \snippet code/doc_src_qmake-manual.pro 79

    The \c path member informs qmake that the files
    should be installed in \c /usr/local/program/doc (the path member), and the
    \c files member specifies the files that should be copied to the
    installation directory. In this case, everything in the \c docs directory
    will be copied to \c /usr/local/program/doc.

    Once an install set has been fully described, you can append it to the
    install list with a line like this:

    \snippet code/doc_src_qmake-manual.pro 80

    qmake will ensure that the specified files are
    copied to the installation directory. If you require more control over
    this process, you can also provide a definition for the \c extra member of
    the object. For example, the following line tells
    qmake to execute a series of commands for this
    install set:

    \snippet code/doc_src_qmake-manual.pro 81

    The \c unix \l{Scopes and Conditions}{scope}
    ensures that these particular commands are only executed on Unix platforms.
    Appropriate commands for other platforms can be defined using other scope
    rules.

    Commands specified in the \c extra member are executed before the instructions
    in the other members of the object are performed.

    If you append a built-in install set to the \c INSTALLS variable and do
    not specify \c files or \c extra members, qmake
    will decide what needs to be copied for you. Currently, the \c target and \c dlltarget
    install sets are supported. For example:

    \snippet code/doc_src_qmake-manual.pro 82

    In the above lines, qmake knows what needs to
    be copied, and will handle the installation process automatically.

    \section1 Adding Custom Targets

    qmake tries to do everything expected of a
    cross-platform build tool. This is often less than ideal when you really
    need to run special platform-dependent commands. This can be achieved with
    specific instructions to the different qmake backends.

    Customization of the Makefile output is performed through an object-style
    API as found in other places in qmake. Objects are defined automatically by
    specifying their \e members. For example:

    \snippet code/doc_src_qmake-manual.pro 86

    The definitions above define a qmake target called \c mytarget, containing a
    Makefile target called \c{.buildfile} which in turn is generated with the
    \l{touchfunction}{touch()} function. Finally, the
    \c{.depends} member specifies that \c mytarget depends on \c mytarget2,
    another target that is defined afterwards. \c mytarget2 is a dummy target.
    It is only defined to echo some text to the console.

    The final step is to use the \c QMAKE_EXTRA_TARGETS variable to instruct
    qmake that this object is a target to be built:

    \snippet code/doc_src_qmake-manual.pro 87

    This is all you need to do to actually build custom targets. Of course,
    you may want to tie one of these targets to the
    \l{TARGET}{qmake build target}. To do this, you
    simply need to include your Makefile target in the list of
    \l{PRE_TARGETDEPS}.

    Custom target specifications support the following members:

    \table
    \header
        \li Member
        \li Description
    \row
        \li commands
        \li The commands for generating the custom build target.
    \row
        \li CONFIG
        \li Specific configuration options for the custom build target. Can be
            set to \c recursive to indicate that rules should be created in the
            Makefile to call the relevant target inside the sub-target specific
            Makefile. This member defaults to creating an entry for each of the
            sub-targets.
    \row
        \li depends
        \li The existing build targets that the custom build target depends on.
    \row
        \li recurse
        \li Specifies which sub-targets should be used when creating the rules
            in the Makefile to call in the sub-target specific Makefile. This
            member is used only when \c recursive is set in \c CONFIG. Typical
            values are "Debug" and "Release".
    \row
        \li recurse_target
        \li Specifies the target that should be built via the sub-target
            Makefile for the rule in the Makefile. This member adds something
            like \c {$(MAKE) -f Makefile.[subtarget] [recurse_target]}. This
            member is used only when \c recursive is set in \c CONFIG.
    \row
        \li target
        \li The name of the custom build target.
    \endtable

    \section1 Adding Compilers

    It is possible to customize qmake to support new compilers and
    preprocessors:

    \snippet code/doc_src_qmake-manual.pro 88

    With the above definitions, you can use a drop-in replacement for moc if one
    is available. The command is executed on all arguments given to the
    \c NEW_HEADERS variable (from the \c input member), and the result is written
    to the file defined by the \c output member. This file is added to the
    other source files in the project. Additionally, qmake will execute
    \c depend_command to generate dependency information, and place this
    information in the project as well.

    Custom compiler specifications support the following members:

    \table
    \header
        \li Member
        \li Description
    \row
        \li commands
        \li The commands used for for generating the output from the input.
    \row
        \li CONFIG
        \li Specific configuration options for the custom compiler. See the
            CONFIG table for details.
    \row
        \li depend_command
        \li Specifies a command used to generate the list of dependencies for
            the output.
    \row
        \li dependency_type
        \li Specifies the type of file the output is. If it is a known type
            (such as TYPE_C, TYPE_UI, TYPE_QRC), it is handled as one of those
            type of files.
    \row
        \li depends
        \li Specifies the dependencies of the output file.
    \row
        \li input
        \li The variable that specifies the files that should be processed with
            the custom compiler.
    \row
        \li name
        \li A description of what the custom compiler is doing.  This is only
            used in some backends.
    \row
        \li output
        \li The filename that is created from the custom compiler.
    \row
        \li output_function
        \li Specifies a custom qmake function that is used to specify the
            filename to be created.
    \row
        \li variables
        \li Indicates that the variables specified here are replaced with
            $(QMAKE_COMP_VARNAME) when referred to in the pro file as
            $(VARNAME).
    \row
        \li variable_out
        \li The variable that the files created from the output should be added
            to.
    \endtable

    The CONFIG member supports the following options:

    \table
    \header
        \li Option
        \li Description
    \row
        \li combine
        \li Indicates that all of the input files are combined into a single
            output file.
    \row
        \li target_predeps
        \li Indicates that the output should be added to the list of
            \l{PRE_TARGETDEPS}.
    \row
        \li explicit_dependencies
        \li The dependencies for the output only get generated from the depends
            member and from nowhere else.
    \row
        \li no_link
        \li Indicates that the output should not be added to the list of objects
            to be linked in.
    \endtable

    \target LibDepend
    \section1 Library Dependencies

    Often when linking against a library, qmake
    relies on the underlying platform to know what other libraries this
    library links against, and lets the platform pull them in. In many cases,
    however, this is not sufficient. For example, when statically linking a
    library, no other libraries are linked to, and therefore no dependencies
    to those libraries are created. However, an application that later links
    against this library will need to know where to find the symbols that
    the static library will require. qmake attempts to keep track of the
    dependencies of a library, where appropriate, if you explicitly enable
    tracking.

    The first step is to enable dependency tracking in the library itself.
    To do this you must tell qmake to save information about the library:

    \snippet code/doc_src_qmake-manual.pro 83

    This is only relevant to the \c lib template, and will be ignored for all
    others. When this option is enabled, qmake will create a file ending in .prl
    which will save some meta-information about the library. This metafile is
    just like an ordinary project file, but only contains internal variable
    declarations. When installing this library, by specifying it as a target in
    an \l{INSTALLS} declaration, qmake will automatically copy the .prl file to
    the installation path.

    The second step in this process is to enable reading of this meta
    information in the applications that use the static library:

    \snippet code/doc_src_qmake-manual.pro 84

    When this is enabled, qmake will process all
    libraries linked to by the application and find their meta-information.
    qmake will use this to determine the relevant
    linking information, specifically adding values to the application project
    file's list of \l{DEFINES} as well as \l{LIBS}. Once
    qmake has processed this file, it will then
    look through the newly introduced libraries in the \c LIBS variable, and
    find their dependent .prl files, continuing until all libraries have been
    resolved. At this point, the Makefile is created as usual, and the
    libraries are linked explicitly against the application.

    The .prl files should be created by qmake only, and should not be
    transferred between operating systems, as they may contain
    platform-dependent information.
*/

/*!
    \page qmake-precompiledheaders.html
    \title Using Precompiled Headers
    \contentspage {qmake Manual}{Contents}
    \previouspage Advanced Usage
    \nextpage Configuring qmake

    \target Introduction

    Precompiled headers (PCH) are a performance feature supported by some
    compilers to compile a stable body of code, and store the compiled
    state of the code in a binary file. During subsequent compilations,
    the compiler will load the stored state, and continue compiling the
    specified file. Each subsequent compilation is faster because the
    stable code does not need to be recompiled.

    qmake supports the use of precompiled headers
    on some platforms and build environments, including:
    \list
    \li Windows
        \list
        \li nmake
        \li Visual Studio projects (VS 2008 and later)
        \endlist
    \li Mac OS X
        \list
        \li Makefile
        \li Xcode
        \endlist
    \li Unix
        \list
        \li GCC 3.4 and above
        \endlist
    \endlist

    \target ADD_PCH
    \section1 Adding Precompiled Headers to Your Project

    The precompiled header must contain code which is \e stable
    and \e static throughout your project. A typical precompiled header might
    look like this:

    \snippet code/doc_src_qmake-manual.cpp 104

    \note A precompiled header file needs to separate C includes from
    C++ includes, since the precompiled header file for C files may not
    contain C++ code.

    \target PROJECT_OPTIONS
    \section2 Project Options

    To make your project use precompiled headers, you only need to define the
    \l{PRECOMPILED_HEADER} variable in your project file:

    \snippet code/doc_src_qmake-manual.pro 105

    qmake will handle the rest, to ensure the
    creation and use of the precompiled header file. You do not need to
    include the precompiled header file in \c HEADERS, as
    qmake will do this if the configuration supports precompiled headers.

    The MSVC and g++ specs targeting Windows (and Windows CE) enable
    \c precompile_header by default.

    Using this option, you may trigger
    conditional blocks in your project file to add settings when using
    precompiled headers.
    For example:

    \snippet code/doc_src_qmake-manual.pro 106

    \section1 Notes on Possible Issues

    On some platforms, the file name suffix for precompiled header files is
    the same as that for other object files. For example, the following
    declarations may cause two different object files with the same name to
    be generated:

    \snippet code/doc_src_qmake-manual.pro 107

    To avoid potential conflicts like these, give distinctive names to header
    files that will be precompiled.

    \target EXAMPLE_PROJECT
    \section1 Example Project

    You can find the following source code in the
    \c{examples/qmake/precompile} directory in the Qt distribution:

    \section2 \c mydialog.ui

    The following image displays the mydialog.ui file in Qt Creator Design mode.
    You can view the code in the Edit mode.

    \image qmake-precompile-ui.png

    \section2 \c stable.h

    \snippet qmake/precompile-stable.h 0

    \omit
    ##Keeping the snippet in qtdoc is a workaround, because it contains code
    that would tell qdoc to start a new page. Remove it and put the
    following snippet back after modularizing the docs.
    \snippet examples/qmake/precompile/stable.h 0
    \endomit

    \section2 \c myobject.h

    \code
    #include <QObject>

    class MyObject : public QObject
    {
    public:
        MyObject();
        ~MyObject();
    };
    \endcode

    \omit
    ##Remove the code and put the snippets back after modularizing the docs.
    \snippet examples/qmake/precompile/myobject.h 0
    \endomit

    \section2 \c myobject.cpp

    \code
    #include <iostream>
    #include <QDebug>
    #include <QObject>
    #include "myobject.h"

    MyObject::MyObject()
        : QObject()
    {
        std::cout << "MyObject::MyObject()\n";
    }
    \endcode

    \omit
    \snippet examples/qmake/precompile/myobject.cpp 0
    \endomit

    \section2 \c util.cpp

    \code
    void util_function_does_nothing()
    {
        // Nothing here...
        int x = 0;
        ++x;
    }
    \endcode

    \omit
    \snippet examples/qmake/precompile/util.cpp 0
    \endomit

    \section2 \c main.cpp

    \code
    #include <QApplication>
    #include <QPushButton>
    #include <QLabel>
    #include "myobject.h"
    #include "mydialog.h"

    int main(int argc, char **argv)
    {
        QApplication app(argc, argv);

        MyObject obj;
        MyDialog dialog;

        dialog.connect(dialog.aButton, SIGNAL(clicked()), SLOT(close()));
        dialog.show();

        return app.exec();
    }
    \endcode

    \omit
    \snippet examples/qmake/precompile/main.cpp 0
    \endomit

    \section2 \c precompile.pro

    \code
    TEMPLATE  = app
    LANGUAGE  = C++
    CONFIG   += console precompile_header
    CONFIG   -= app_bundle

    # Use Precompiled headers (PCH)
    PRECOMPILED_HEADER  = stable.h

    HEADERS   = stable.h \
                mydialog.h \
                myobject.h
    SOURCES   = main.cpp \
                mydialog.cpp \
                myobject.cpp \
                util.cpp
    FORMS     = mydialog.ui
    \endcode

    \omit
    \snippet examples/qmake/precompile/precompile.pro 0
    \endomit
*/

/*!
    \target qmake-getting-started
    \page qmake-tutorial.html
    \title Getting Started
    \contentspage {qmake Manual}{Contents}
    \previouspage Overview
    \nextpage Creating Project Files

    This tutorial teaches you the basics of qmake. The other topics in this
    manual contain more detailed information about using qmake.

    \section1 Starting off Simple

    Let's assume that you have just finished a basic implementation of
    your application, and you have created the following files:

    \list
    \li hello.cpp
    \li hello.h
    \li main.cpp
    \endlist

    You will find these files in the \c{examples/qmake/tutorial} directory
    of the Qt distribution. The only other thing you know about the setup of
    the application is that it's written in Qt.  First, using your favorite
    plain text editor, create a file called \c hello.pro in
    \c{examples/qmake/tutorial}. The first thing you need to do is add the
    lines that tell qmake about the source and
    header files that are part of your development project.

    We'll add the source files to the project file first.  To do this you
    need to use the \l{SOURCES} variable.
    Just start a new line with \c {SOURCES +=} and put hello.cpp after it.
    You should have something like this:

    \snippet code/doc_src_qmake-manual.pro 108

    We repeat this for each source file in the project, until we end up
    with the following:

    \snippet code/doc_src_qmake-manual.pro 109

    If you prefer to use a Make-like syntax, with all the files listed in
    one go you can use the newline escaping like this:

    \snippet code/doc_src_qmake-manual.pro 110

    Now that the source files are listed in the project file, the header
    files must be added. These are added in exactly the same way as source
    files, except that the variable name we use is \l{HEADERS}.

    Once you have done this, your project file should look something like
    this:

    \snippet code/doc_src_qmake-manual.pro 111

    The target name is set automatically. It is the same as the project
    filename, but with the suffix appropriate for the platform. For example, if
    the project file is called \c hello.pro, the target will be \c hello.exe
    on Windows and \c hello on Unix. If you want to use a different name
    you can set it in the project file:

    \snippet code/doc_src_qmake-manual.pro 112

    The finished project file should look like this:

    \snippet code/doc_src_qmake-manual.pro 113

    You can now use qmake to generate a Makefile
    for your application. On the command line, in your project directory,
    type the following:

    \snippet code/doc_src_qmake-manual.pro 114

    Then type \c make or \c nmake depending on the compiler you use.

    For Visual Studio users, qmake can also generate Visual Studio project
    files. For example:

    \snippet code/doc_src_qmake-manual.pro 115

    \section1 Making an Application Debuggable

    The release version of an application does not contain any debugging
    symbols or other debugging information. During development, it is useful
    to produce a debugging version of the application that has the
    relevant information. This is easily achieved by adding \c debug to the
    \l{CONFIG} variable in the project file.

    For example:

    \snippet code/doc_src_qmake-manual.pro 116

    Use qmake as before to generate a Makefile. You will now obtain useful
    information about your application when running it in a debugging
    environment.

    \section1 Adding Platform-Specific Source Files

    After a few hours of coding, you might have made a start on the
    platform-specific part of your application, and decided to keep the
    platform-dependent code separate.  So you now have two new files to
    include into your project file: \c hellowin.cpp and \c
    hellounix.cpp.  We cannot just add these to the \c SOURCES
    variable since that would place both files in the Makefile. So, what we
    need to do here is to use a scope which will be processed depending on
    which platform we are building for.

    A simple scope that adds the platform-dependent file for
    Windows looks like this:

    \snippet code/doc_src_qmake-manual.pro 117

    When building for Windows, qmake adds \c hellowin.cpp to the list of source
    files. When building for any other platform, qmake simply ignores it. Now
    all that is left to be done is to create a scope for the Unix-specific file.

    When you have done that, your project file should look
    something like this:

    \snippet code/doc_src_qmake-manual.pro 118

    Use qmake as before to generate a Makefile.

    \section1 Stopping qmake If a File Does Not Exist

    You may not want to create a Makefile if a certain file does not exist.
    We can check if a file exists by using the \l{exists(filename)}{exists()}
    function. We can stop qmake from processing by using the \l{error(string)}
    {error()} function. This works in the same way as scopes do. Simply replace
    the scope condition with the function. A check for a file called main.cpp looks
    like this:

    \snippet code/doc_src_qmake-manual.pro 119

    The \c{!} symbol is used to negate the test. That is, \c{exists( main.cpp )}
    is true if the file exists, and \c{!exists( main.cpp )} is true if the
    file does not exist.

    \snippet code/doc_src_qmake-manual.pro 120

    Use qmake as before to generate a makefile.
    If you rename \c main.cpp temporarily, you will see the message and
    qmake will stop processing.

    \section1 Checking for More than One Condition

    Suppose you use Windows and you want to be able to see statement
    output with \c {qDebug()} when you run your application on the command line.
    To see the output, you must build your application with the appropriate
    console setting. We can easily put \c console on the \c CONFIG
    line to include this setting in the Makefile on Windows. However,
    let's say that we only want to add the \c CONFIG line when we are running
    on Windows \e and when \c debug is already on the \c CONFIG line.
    This requires using two nested scopes. First create one scope, then create
    the other inside it. Put the settings to be processed inside the second
    scope, like this:

    \snippet code/doc_src_qmake-manual.pro 121

    Nested scopes can be joined together using colons, so the final
    project file looks like this:

    \snippet code/doc_src_qmake-manual.pro 122

    That's it! You have now completed the tutorial for
    qmake, and are ready to write project files for
    your development projects.
*/

/*!
    \page qmake-common-projects.html
    \title Building Common Project Types
    \contentspage {qmake Manual}{Contents}
    \previouspage Creating Project Files
    \nextpage Running qmake

    This chapter describes how to set up qmake project files for three common
    project types that are based on Qt: application, library, and plugin.
    Although all project types use many of the same variables, each of
    them uses project-specific variables to customize output files.

    Platform-specific variables are not described here. For more information,
    see  \l{Deploying an Application on Windows} and
    \l{Developing Qt Applications for Mac OS X}.

    \target Application
    \section1 Building an Application

    The \c app template tells qmake to generate a
    Makefile that will build an application. With this template, the type of
    application can be specified by adding one of the following options to the
    \l{CONFIG} variable definition:

    \table
    \header \li Option  \li Description
    \row    \li windows \li The application is a Windows GUI application.
    \row    \li console \li \c app template only: the application is a Windows console
                       application.
    \row    \li testcase \li The application is \l{Building a Testcase}{an automated test}.
    \endtable

    When using this template, the following qmake
    system variables are recognized. You should use these in your .pro file to
    specify information about your application.

    \list
    \li \l{HEADERS} - A list of header files for the application.
    \li \l{SOURCES} - A list of C++ source files for the application.
    \li \l{FORMS} - A list of UI files for the application (created using
        Qt Designer).
    \li \l{LEXSOURCES} - A list of Lex source files for the application.
    \li \l{YACCSOURCES} - A list of Yacc source files for the
        application.
    \li \l{TARGET} - Name of the executable for the application. This defaults
    to the name of the project file. (The extension, if any, is added
    automatically).
    \li \l{DESTDIR} - The directory in which the target executable is placed.
    \li \l{DEFINES} - A list of any additional pre-processor defines needed for
        the application.
    \li \l{INCLUDEPATH} - A list of any additional include paths needed for the
        application.
    \li \l{DEPENDPATH} - The dependency search path for the application.
    \li \l{VPATH} - The search path to find supplied files.
    \li \l{DEF_FILE} - Windows only: A .def file to be linked against for the
        application.
    \li \l{RC_FILE} - Windows only: A resource file for the application.
    \li \l{RES_FILE} - Windows only: A resource file to be linked against for
        the application.
    \endlist

    You only need to use the system variables that you have values for. For
    example, if you do not have any extra INCLUDEPATHs then you do not need
    to specify any. qmake will add the necessary default values.
    An example project file might look like this:

    \snippet code/doc_src_qmake-manual.pro 123

    For items that are single valued, such as the template or the destination
    directory, we use "="; but for multi-valued items we use "+=" to \e
    add to the existing items of that type. Using "=" replaces the variable
    value with the new value. For example, if we write \c{DEFINES=USE_MY_STUFF},
    all other definitions are deleted.

    \section1 Building a Testcase

    A testcase project is an \c app project intended to be run as an automated
    test. Any \c app may be marked as a testcase by adding the value \c testcase
    to the \c CONFIG variable.

    For testcase projects, qmake will insert a \c check
    target into the generated Makefile. This target will run the application.
    The test is considered to pass if it terminates with an exit code equal to zero.

    The \c check target automatically recurses through
    \l{SUBDIRS} projects. This means it is
    possible to issue a \c{make check} command from within a SUBDIRS project
    to run an entire test suite.

    The execution of the \c check target may be customized by certain Makefile
    variables. These variables are:

    \table
    \header
        \li Variable
        \li Description
    \row
        \li TESTRUNNER
        \li A command or shell fragment prepended to each test command. An example
            use-case is a "timeout" script which will terminate a test if it does not
            complete within a specified time.
    \row
        \li TESTARGS
        \li Additional arguments appended to each test command. For example, it may
            be useful to pass additional arguments to set the output file and format
            from the test (such as the \c{-o filename,format} option supported by
            \l{QTestLib}).
    \endtable

    \note The variables must be set while invoking the \c make tool, not in the
    .pro file. Most \c make tools support the setting of Makefile variables directly
    on the command-line:

    \code
        # Run tests through test-wrapper and use xunitxml output format.
        # In this example, test-wrapper is a fictional wrapper script which terminates
        # a test if it does not complete within the amount of seconds set by "--timeout".
        # The "-o result.xml,xunitxml" options are interpreted by QTestLib.
        make check TESTRUNNER="test-wrapper --timeout 120" TESTARGS="-o result.xml,xunitxml"
    \endcode

    Testcase projects may be further customized with the following \c CONFIG options:

    \table
    \header
        \li Option
        \li Description
    \row
        \li insignificant_test
        \li The exit code of the test will be ignored during \c{make check}.
    \endtable

    Testcases will often be written with \l{QTest} or \l{TestCase}, but
    that is not a requirement to make use of \c{CONFIG+=testcase} and \c{make check}.
    The only primary requirement is that the test program exit with a zero exit code
    on success, and a non-zero exit code on failure.

    \target Library
    \section1 Building a Library

    The \c lib template tells qmake to generate a Makefile that will build a
    library.  When using this template, the \l{VERSION} variable is supported,
    in addition to the system variables that the \c app template supports. Use
    the variables in your .pro file to specify information about the library.

    When using the \c lib template, the following options can be added to the
    \l{CONFIG} variable to determine the type of library that is built:

    \table
    \header \li Option    \li Description
    \row    \li dll       \li The library is a shared library (dll).
    \row    \li staticlib \li The library is a static library.
    \row    \li plugin    \li The library is a plugin.
    \endtable

    The following option can also be defined to provide additional information about
    the library.

    \list
    \li VERSION - The version number of the target library. For example, 2.3.1.
    \endlist

    The target file name for the library is platform-dependent. For example, on
    X11 and Mac OS X, the library name will be prefixed by \c lib. On Windows,
    no prefix is added to the file name.

    \target Plugin
    \section1 Building a Plugin

    Plugins are built using the \c lib template, as described in the previous
    section. This tells qmake to generate a
    Makefile for the project that will build a plugin in a suitable form for
    each platform, usually in the form of a library. As with ordinary
    libraries, the \l{VERSION} variable is used to specify information about the
    plugin.

    \list
    \li VERSION - The version number of the target library. For example, 2.3.1.
    \endlist

    \section2 Building a Qt Designer Plugin

    \QD plugins are built using a specific set of configuration settings that
    depend on the way Qt was configured for your system. For convenience, these
    settings can be enabled by adding \c designer to the \l{Variables#QT}{QT}
    variable. For example:

    \code
    QT          += widgets designer
    \endcode

    See the \l{Qt Designer Examples} for more examples of plugin-based projects.

    \section1 Building and Installing in Debug and Release Modes

    Sometimes, it is necessary to build a project in both debug and release
    modes. Although the \l{CONFIG} variable can hold both \c debug and \c release
    options, the \c debug option overrides the \c release option.

    \section2 Building in Both Modes

    To enable a project to be built in both modes, you must add the
    \c debug_and_release option to the \c CONFIG variable:

    \snippet qmake/debug_and_release.pro 0
    \snippet qmake/debug_and_release.pro 1

    The scope in the above snippet modifies the build target in each mode to
    ensure that the resulting targets have different names. Providing different
    names for targets ensures that one will not overwrite the other.

    When qmake processes the project file, it will
    generate a Makefile rule to allow the project to be built in both modes.
    This can be invoked in the following way:

    \snippet code/doc_src_qmake-manual.pro 124

    The \c build_all option can be added to the \c CONFIG variable in the
    project file to ensure that the project is built in both modes by default:

    \snippet qmake/debug_and_release.pro 2

    This allows the Makefile to be processed using the default rule:

    \snippet code/doc_src_qmake-manual.pro 125

    \section2 Installing in Both Modes

    The \c build_all option also ensures that both versions of the target
    will be installed when the installation rule is invoked:

    \snippet code/doc_src_qmake-manual.pro 126

    It is possible to customize the names of the build targets depending on
    the target platform. For example, a library or plugin may be named using a
    different convention on Windows from the one used on Unix platforms:

    \omit
    Note: This was originally used in the customwidgetplugin.pro file, but is
    no longer needed there.
    \endomit
    \snippet code/doc_src_qmake-manual.pro 127

    The default behavior in the above snippet is to modify the name used for
    the build target when building in debug mode. An \c else clause could be
    added to the scope to do the same for release mode. Left as it is, the
    target name remains unmodified.
*/
