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# qmake Platform Notes

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

- Mac OS X

- Source and Binary Packages
- Using Frameworks
- Creating Library Bundles
- Creating Frameworks
- Creating Universal Binaries
- Creating and Moving Xcode Projects

- Windows

- Creating Visual Studio Project Files
- Visual Studio 2005 Manifest Files

## Mac OS X

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

### 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 `macx-g++` specification, the binary package is typically configured to use the `macx-xcode` specification.

Users of each package can override this configuration by invoking `qmake` with the `-spec` option (see Running qmake for more information). This makes it possible, for example, to use `qmake` from a binary package to create a Makefile in a project directory with the following command line invocation:

        qmake -spec macx-g++

### 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 `/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 QMAKE_LFLAGS variable, as shown in the following example:

        QMAKE_LFLAGS += -L/path/to/framework/directory/

The framework itself is linked in by appending the `-framework` options and the name of the framework to the LIBS variable:

        LIBS += -framework TheFramework

### Creating Library Bundles

Any given library project can be configured so that the resulting library file is placed in a library bundle, ready for deployment. To do this, set up the project to use the `lib` template and add the `lib_bundle` option to the CONFIG variable:

        TEMPLATE = lib
        CONFIG += lib_bundle

The data associated with the library is specified using the 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:

        FRAMEWORK_HEADERS.version = Versions
        FRAMEWORK_HEADERS.files = path/to/header_one.h path/to/header_two.h
        FRAMEWORK_HEADERS.path = Headers
        QMAKE_BUNDLE_DATA += FRAMEWORK_HEADERS

Here, the `FRAMEWORK_HEADERS` variable is a user-defined variable that is used to define the headers required to use a particular framework. Appending it to the `QMAKE_BUNDLE_DATA` variable ensures that the information about these headers are added to the collection of resources that will be installed with the library bundle.

See Deploying an Application on Qt/Mac for more information about deploying applications and libraries.

### Creating Frameworks

In addition to libraries and library bundles, `qmake` can generate rules to build frameworks.

To enable this, you need to configure the project to generate a library bundle as described in the previous section:

            TEMPLATE = lib
            CONFIG += lib_bundle

The end product of the build process is a framework whose name and version are specified by the QMAKE_FRAMEWORK_BUNDLE_NAME and QMAKE_FRAMEWORK_VERSION variables. By default, the values used for these are obtained from the TARGET and VERSION variables.

See Deploying an Application on Qt/Mac for more information about building and deploying frameworks.

### Creating Universal Binaries

To create a universal binary for your application, you need to be using a version of Qt that has been configured with the `-universal` option.

The architectures to be supported in the binary are specified with the CONFIG variable. For example, the following assignment causes `qmake` to generate build rules to create a universal binary for both PowerPC and x86 architectures:

            CONFIG += x86 ppc

Additionally, developers using a PowerPC-based platform need to set the QMAKE_MAC_SDK variable. This process is discussed in more detail in the deployment guide for Mac OS X.

### Creating and Moving Xcode Projects

Developers on Mac OS X can take advantage of `qmake`'s support for Xcode project files, as described in Qt/Mac is Mac OS X Native, by running `qmake` to generate an Xcode project from an existing `qmake` project files. For example:

        qmake -spec macx-xcode project.pro

Note that, 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.

## 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.

### Creating Visual Studio Project Files

Developers using Visual Studio to write Qt applications can use the Visual Studio integration facilities provided with the Qt Commercial Editions 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 their development environment. This is achieved by setting the `qmake` project template to either `vcapp` (for application projects) or `vclib` (for library projects).

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

        qmake -t vcapp

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

### Visual Studio 2005 Manifest Files

When deploying Qt applications built using Visual Studio 2005, it is necessary to ensure that the manifest file, created when the application was linked, is handled correctly. This is handled automatically for projects that generate DLLs, but it is necessary to explicitly enable manifest embedding for application executables with the following assignment to the CONFIG variable:

            CONFIG += embed_manifest_exe

This is discussed in more detail in the deployment guide for Windows.