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Diffstat (limited to 'Help/manual/cmake-generator-expressions.7.rst')
| -rw-r--r-- | Help/manual/cmake-generator-expressions.7.rst | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/Help/manual/cmake-generator-expressions.7.rst b/Help/manual/cmake-generator-expressions.7.rst index 76fd3d9..bddf827 100644 --- a/Help/manual/cmake-generator-expressions.7.rst +++ b/Help/manual/cmake-generator-expressions.7.rst @@ -31,7 +31,9 @@ Logical Expressions Logical expressions are used to create conditional output. The basic expressions are the ``0`` and ``1`` expressions. Because other logical expressions evaluate to either ``0`` or ``1``, they can be composed to -create conditional output:: +create conditional output: + +.. code-block:: cmake $<$<CONFIG:Debug>:DEBUG_MODE> @@ -151,14 +153,18 @@ Informational Expressions ========================= These expressions expand to some information. The information may be used -directly, eg:: +directly, eg: + +.. code-block:: cmake include_directories(/usr/include/$<CXX_COMPILER_ID>/) expands to ``/usr/include/GNU/`` or ``/usr/include/Clang/`` etc, depending on the Id of the compiler. -These expressions may also may be combined with logical expressions:: +These expressions may also may be combined with logical expressions: + +.. code-block:: cmake $<$<VERSION_LESS:$<CXX_COMPILER_VERSION>,4.2.0>:OLD_COMPILER> @@ -232,7 +238,10 @@ Available informational expressions are: expression is evaluated on. ``$<TARGET_PROPERTY:prop>`` Value of the property ``prop`` on the target on which the generator - expression is evaluated. + expression is evaluated. Note that for generator expressions in + :ref:`Target Usage Requirements` this is the value of the property + on the consuming target rather than the target specifying the + requirement. ``$<INSTALL_PREFIX>`` Content of the install prefix when the target is exported via :command:`install(EXPORT)` and empty otherwise. @@ -246,18 +255,24 @@ Output Expressions These expressions generate output, in some cases depending on an input. These expressions may be combined with other expressions for information or logical -comparison:: +comparison: + +.. code-block:: cmake -I$<JOIN:$<TARGET_PROPERTY:INCLUDE_DIRECTORIES>, -I> generates a string of the entries in the :prop_tgt:`INCLUDE_DIRECTORIES` target property with each entry preceded by ``-I``. Note that a more-complete use in this situation would require first checking if the INCLUDE_DIRECTORIES -property is non-empty:: +property is non-empty: + +.. code-block:: cmake $<$<BOOL:${prop}>:-I$<JOIN:${prop}, -I>> -where ``${prop}`` refers to a helper variable:: +where ``${prop}`` refers to a helper variable: + +.. code-block:: cmake set(prop "$<TARGET_PROPERTY:INCLUDE_DIRECTORIES>") |