From cd8c79e1633f091fca890df534d98e5eeb63b747 Mon Sep 17 00:00:00 2001 From: Brad King Date: Fri, 5 Oct 2018 09:54:29 -0400 Subject: Help: Clarify target_link_libraries keywords and generator expressions The `optimized` and `debug` keyword items are meaningful only to the `target_link_libraries` command and have no meaning when produced by a generator expression. State this explicitly. Also recommend use of a quoted argument when the genex itself may contain a semicolon. Fixes: #18424 --- Help/command/target_link_libraries.rst | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/Help/command/target_link_libraries.rst b/Help/command/target_link_libraries.rst index e1c374e..229d10c 100644 --- a/Help/command/target_link_libraries.rst +++ b/Help/command/target_link_libraries.rst @@ -78,6 +78,20 @@ Each ```` may be: flags explicitly. The flags will then be placed at the toolchain-defined flag position in the link command. +* **A generator expression**: A ``$<...>`` :manual:`generator expression + ` may evaluate to any of the above + items or to a :ref:`;-list ` of them. + If the ``...`` contains any ``;`` characters, e.g. after evaluation + of a ``${list}`` variable, be sure to use an explicitly quoted + argument ``"$<...>"`` so that this command receives it as a + single ````. + + Additionally, a generator expression may be used as a fragment of + any of the above items, e.g. ``foo$<1:_d>``. + + Note that generator expressions will not be used in OLD handling of + policy :policy:`CMP0003` or policy :policy:`CMP0004`. + * A ``debug``, ``optimized``, or ``general`` keyword immediately followed by another ````. The item following such a keyword will be used only for the corresponding build configuration. The ``debug`` keyword @@ -88,18 +102,16 @@ Each ```` may be: optional. Higher granularity may be achieved for per-configuration rules by creating and linking to :ref:`IMPORTED library targets `. + These keywords are interpreted immediately by this command and therefore + have no special meaning when produced by a generator expression. Items containing ``::``, such as ``Foo::Bar``, are assumed to be :ref:`IMPORTED ` or :ref:`ALIAS ` library target names and will cause an error if no such target exists. See policy :policy:`CMP0028`. -Arguments to ``target_link_libraries`` may use "generator expressions" -with the syntax ``$<...>``. Note however, that generator expressions -will not be used in OLD handling of :policy:`CMP0003` or :policy:`CMP0004`. -See the :manual:`cmake-generator-expressions(7)` manual for available -expressions. See the :manual:`cmake-buildsystem(7)` manual for more on -defining buildsystem properties. +See the :manual:`cmake-buildsystem(7)` manual for more on defining +buildsystem properties. Libraries for a Target and/or its Dependents ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -- cgit v0.12