From 9abd63dd3aea53008d1d01dc361a1a486215520c Mon Sep 17 00:00:00 2001 From: Arcturus Arcturus Date: Fri, 29 Oct 2021 23:02:34 +0100 Subject: Help: Explain how target SOURCES are interpreted Co-Authored-By: Craig Scott --- Help/prop_tgt/SOURCES.rst | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/Help/prop_tgt/SOURCES.rst b/Help/prop_tgt/SOURCES.rst index 493643e..1ebfa14 100644 --- a/Help/prop_tgt/SOURCES.rst +++ b/Help/prop_tgt/SOURCES.rst @@ -1,6 +1,38 @@ SOURCES ------- -Source names specified for a target. +This specifies the list of paths to source files for the target. +The following commands all set or add to the ``SOURCES`` target property +and are the usual way to manipulate it: -List of sources specified for a target. +* :command:`add_executable` +* :command:`add_library` +* :command:`add_custom_target` +* :command:`target_sources` + +Contents of ``SOURCES`` may use +:manual:`generator expressions `. +If a path starts with a generator expression, it is expected to +evaluate to an absolute path. Not doing so is considered undefined behavior. + +Paths that are for files generated by the build will be treated +as relative to the build directory of the target, if the path is not +already specified as an absolute path. Note that whether a file is seen as +generated may be affected by policy :policy:`CMP0118`. + +If a path does not start with a generator expression, is not an +absolute path and is not a generated file, it will be treated as relative to +the location selected by the first of the following that matches: + +* If a file by the specified path exists relative to the target's source + directory, use that file. +* If policy :policy:`CMP0115` is not set to ``NEW``, try appending each + known source file extension to the path and check if that exists + relative to the target's source directory. +* Repeat the above two steps, this time relative to the target's binary + directory instead. + +Note that the above decisions are made at generation time, not build time. + +See the :manual:`cmake-buildsystem(7)` manual for more on defining +buildsystem properties. -- cgit v0.12 From 9fac18a4a666b0c6b6b66a05ac2aa0c515a4681a Mon Sep 17 00:00:00 2001 From: Arcturus Arcturus Date: Thu, 28 Oct 2021 22:05:26 +1100 Subject: Help: Clarify target_sources path conversion w.r.t generator expressions With some of the content expanded, reorder a few paragraphs and tweak some of the wording to improve the flow. Co-Authored-By: Craig Scott --- Help/command/target_sources.rst | 49 ++++++++++++++++++++++++++--------------- 1 file changed, 31 insertions(+), 18 deletions(-) diff --git a/Help/command/target_sources.rst b/Help/command/target_sources.rst index 2fded5e..2039da5 100644 --- a/Help/command/target_sources.rst +++ b/Help/command/target_sources.rst @@ -15,37 +15,50 @@ Specifies sources to use when building a target and/or its dependents. The named ```` must have been created by a command such as :command:`add_executable` or :command:`add_library` or :command:`add_custom_target` and must not be an -:ref:`ALIAS target `. - -.. versionchanged:: 3.13 - Relative source file paths are interpreted as being relative to the current - source directory (i.e. :variable:`CMAKE_CURRENT_SOURCE_DIR`). - See policy :policy:`CMP0076`. +:ref:`ALIAS target `. The ```` may use +:manual:`generator expressions `. .. versionadded:: 3.20 ```` can be a custom target. The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to -specify the scope of the items following them. ``PRIVATE`` and ``PUBLIC`` -items will populate the :prop_tgt:`SOURCES` property of -````, which are used when building the target itself. +specify the scope of the source file paths (````) that follow +them. ``PRIVATE`` and ``PUBLIC`` items will populate the :prop_tgt:`SOURCES` +property of ````, which are used when building the target itself. ``PUBLIC`` and ``INTERFACE`` items will populate the :prop_tgt:`INTERFACE_SOURCES` property of ````, which are used -when building dependents. -The following arguments specify sources. Repeated calls for the same -```` append items in the order called. The targets created by -:command:`add_custom_target` can only have ``PRIVATE`` scope. +when building dependents. A target created by :command:`add_custom_target` +can only have ``PRIVATE`` scope. + +Repeated calls for the same ```` append items in the order called. .. versionadded:: 3.3 Allow exporting targets with :prop_tgt:`INTERFACE_SOURCES`. .. versionadded:: 3.11 - Allow setting ``INTERFACE`` items on :ref:`IMPORTED targets `. + Allow setting ``INTERFACE`` items on + :ref:`IMPORTED targets `. + +.. versionchanged:: 3.13 + Relative source file paths are interpreted as being relative to the current + source directory (i.e. :variable:`CMAKE_CURRENT_SOURCE_DIR`). + See policy :policy:`CMP0076`. + +A path that begins with a generator expression is left unmodified. +When a target's :prop_tgt:`SOURCE_DIR` property differs from +:variable:`CMAKE_CURRENT_SOURCE_DIR`, use absolute paths in generator +expressions to ensure the sources are correctly assigned to the target. + +.. code-block:: cmake + + # WRONG: starts with generator expression, but relative path used + target_sources(MyTarget "$<$:dbgsrc.cpp>") + + # CORRECT: absolute path used inside the generator expression + target_sources(MyTarget "$<$:${CMAKE_CURRENT_SOURCE_DIR}/dbgsrc.cpp>") -Arguments to ``target_sources`` may use "generator expressions" -with the syntax ``$<...>``. 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. .. code-block:: cmake -- cgit v0.12