This tracking was added during the development of commit 042ecf04
(Add API to calculate link-interface-dependent bool properties
or error., 2013-01-06), but was never used.
It was not necessary to use the content because what is really
useful in that logic is to determine if a property has been implied
to be null by appearing in a LINK_LIBRARIES genex.
I think the motivating usecase for developing the feature of
keeping track of the targets relevant to a property was that I
thought it would make it possible to allow requiring granular
compatibility of interface properties only for targets which
depended on the interface property. Eg:
add_library(foo ...)
add_library(bar ...)
add_executable(user ...)
# Read the INTERFACE_POSITION_INDEPENDENT_CODE from bar, but not
# from foo:
target_link_libraries(user foo $<$<TARGET_PROPERTY:POSTITION_INDEPENDENT_CODE>:bar>)
This obviously doesn't make sense. We require that INTERFACE
properties are consistent across all linked targets instead.
We need to make sure expressions which evaluate TARGET_PROPERTY:TYPE
multiple times for example get the correct result each time, and
not an empty string instead.
As INTERFACE_COMPILE_DEFINITIONS are now possible, we can have
situations like this:
add_library(foo ...)
add_library(bar ...)
target_link_libraries(foo bar)
target_compile_definitions(bar INTERFACE SOME_DEF)
The INTERFACE_COMPILE_DEFINITIONS of bar determine how foo should be
compiled, and if they change, foo should be rebuilt.
Additionally, as of commit d1446ca7 (Append the COMPILE_DEFINITIONS
from the Makefile to all targets., 2012-09-17), we don't need to
read definitions from the makefile if we read them from the target,
so also de-duplicate the cached info.
The DependInfo for INTERFACE_INCLUDE_DIRECTORIES is already handled
correctly.
Since commit 08cb4fa4 (Process generator expressions in the
INCLUDE_DIRECTORIES property., 2012-09-18), it is possible to use
generator expressions with the include_directories command.
As that command can also have a SYSTEM argument, ensure that the
result of using that argument with generator expressions gives a
sane result.
e48d842 Cache context-independent includes on evaluation.
089fe1c Optimize genex evaluation for includes and defines.
179f495 find_package: Reword <package>_NO_INTERFACES documentation
e7b579b Test workaround of bad interface include directories from depends.
77cecb7 Add includes and compile definitions with target_link_libraries.
0b92602 Add the $<LINKED:...> generator expression.
0fa7f69 Add API to check if we're reading a includes or defines property.
2c3654c Add a way to exclude INTERFACE properties from exported targets.
d4297d5 Export targets to a targets file, not a Config file.
df4d2b2 Make it an error for INSTALL_PREFIX to be evaluated.
7ceeba9 Advance more when preprocessing exported strings.
30268b4 Handle reading empty properties defined by the link interface.
5484c60 Merge branch 'vs6-rule-files' into add-ExternalData-module
1fd8d01 ExternalData: Attach download rules to content links in IDEs
a6d3ffc Fix Module.ExternalData test on VS 6
aed590a Fix Module.ExternalData test on Cygwin
06e8ded Merge branch 'fix-atomic-rename-on-Windows' into add-ExternalData-module
e2e0d2e ExternalData: Collapse ../ components in DATA{} paths
ee2abfd ExternalData: Add support for SHA 1 and 2 hash algorithms
aa8b228 ExternalData: Generalize hash algo/ext handling
9e518a8 ExternalData: Allow DATA{} syntax to reference directories
175ed02 ExternalData: Allow ()-groups in series match regex
4befecc ExternalData: Add tests covering interfaces and errors
bcd2580 ExternalData: Improve series matching using an explicit syntax
c0cebcb ExternalData: Remove unused private interface
5275993 ExternalData: Cleanup stray TODO and typo in comments
7bb8344 ExternalData: Do not match directory names when resolving DATA{}
00d801f ExternalData: Remove compatibility with CMake < 2.8.5
...
The commit 18a3195a ('Keep track of INCLUDE_DIRECTORIES as a vector
of structs.', 2012-11-19) moved the handling of includes from
cmGeneratorTarget to cmTarget, but in the process introduced this
bug.
link.exe has problems with very very long lines in rsp files too.
Use $in_newline instead of $in variable for rspcontent which
separates the arguments with a newline instead of a simple space
and was specially made for this purpose.
Each data file to be created in the build tree corresponds one-to-one with
a raw file or content link in the source tree. Use the MAIN_DEPENDENCY of
add_custom_command to attach the build rule to the source tree file. This
looks much nicer in the IDE project file browser and avoids ".rule" files.
Run the test with the ctest --build-noclean option. The test
CMakeLists.txt file already uses file(REMOVE_RECURSE) to clean out
downloaded data anyway. Some file removed by "msdev ... /clean" causes
CMake to re-run in the middle of the build step and file(REMOVE_RECURSE)
wipes out already-generated files.
Since commit d46d8df0 (Re-implemented cmGeneratedFileStream to look like a
real stream and replace the destination file atomically, 2004-11-03) our
RenameFile implementation tries to deal with MoveFile not replacing
read-only files. In order to avoid the Get/SetFileAttributes pair we used
stat to test for existence of the destination file. This has a race in
which the destination could be created between the test for existence and
the MoveFile call.
Remove the stat call and use GetFileAttributes to detect whether the file
exists. This shortens the race but does not eliminate it. Use a loop to
try multiple times in case we lose the race. While at it, drop Win9x
support and always use MoveFileEx.
Generator expressions whose output depends on the configuration
now record that fact. The GetIncludeDirectories method can use
that result to cache the include directories for later calls.
GetIncludeDirectories is called multiple times for a target
for each configuration, so this should restore performance for
multi-config generators.
While porting boost to use these features, the generation step took
too long (several minutes before I stopped it). The reason was that
the boost libraries form a large interdependent mesh. The libraries
list their dependencies in their INTERFACE such as:
$<LINKED:boost::core>;$<LINKED:boost::config>;$<LINKED:boost::mpl>
As boost::core already depends on the boost::config libraries, that
expression has no impact on the end-content, as it is removed after
the generation step. There is no DAG issue though, so the generator
expression evaluation would fully evaluate them. In the case of the
config library, it also depends on the core library, so all depends
are followed through that again, despite the fact that they've just
been evaluated. After this patch, the evaluation skips libraries if
they have already been seen via depends or directly in the content.
This patch keeps track of targets whose INTERFACE has been consumed
already. The INCLUDE_DIRECTORIES and COMPILE_DEFINITIONS properties
are whitelisted because repeated content will be stripped out later
during generation. For other properties now and in the future, that
may not be the case.
This establishes that linking is used to propagate usage-requirements
between targets in CMake code. The use of the target_link_libraries
command as the API for this is chosen because introducing a new command
would introduce confusion due to multiple commands which differ only in
a subtle way.
This is both a short form of using a TARGET_DEFINED expression
together with a TARGET_PROPERTY definition, and a way to strip
non-target content from interface properties when exporting.
Projects set interface requirements upstream, and existing
downstreams use of target_link_libraries will consume those interfaces.
This can create a backward compatibility concern as the result may
be changing the order of include directories of downstreams, or another
side-effect of using the INTERFACE properties.
Provide a way for them to emulate the behavior of a version-based
policy in the config file.
Stephen Kelly
Kitware Robot
Brad King
Patrick Gansterer