Running qmake

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.

Command Syntax

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

 qmake [mode] [options] files

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 mode can be either of the following two values:

  • -makefile
    qmake output will be a Makefile.
  • -project
    qmake output will be a project file.

    Note: It is likely that the created file will need to be edited. For example, adding the QT variable to suit what modules are required for the project.

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

Files

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

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:

  • -help
    qmake will go over these features and give some useful help.
  • -o file
    qmake output will be directed to 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.
    If '-' is specified, output is directed to stdout.
  • -d
    qmake will output debugging information. Adding -d more than once increases verbosity.

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

  • -t tmpl
    qmake will override any set TEMPLATE variables with tmpl, but only after the .pro file has been processed.
  • -tp prefix
    qmake will add prefix to the TEMPLATE variable.

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

  • -Wall
    qmake will report all known warnings.
  • -Wnone
    No warning information will be generated by qmake.
  • -Wparser
    qmake will only generate parser warnings. This will alert you to common pitfalls and potential problems in the parsing of your project files.
  • -Wlogic
    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.

Makefile Mode Options

 qmake -makefile [options] files

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:

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

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:

 qmake -makefile -o Makefile "CONFIG+=test" test.pro

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

 qmake "CONFIG+=test" test.pro

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

Project Mode Options

 qmake -project [options] files

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

  • -r
    qmake will look through supplied directories recursively.
  • -nopwd
    qmake will not look in your current working directory for source code. It will only use the specified files.

In this mode, the files argument can be a list of files or directories. If a directory is specified, it will be included in the 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 FORMS, and C++ files are added to 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.