INTERFACE libraries were created with the intention of collecting usage
requirements for use by other targets via `target_link_libraries`.
Therefore they were not allowed to have SOURCES and were not included in
the generated buildsystem. In practice, this has become limiting:
* Header-only libraries do have sources, they just do not compile.
Developers should be able to edit those sources (the header files)
in their IDE.
* Header-only libraries may need to generate some of their header
files via custom commands.
Some projects work around these limitations by pairing each interface
library with an `add_custom_target` that makes the header files and
custom commands appear in the generated buildsystem and in IDEs.
Lift such limitations by allowing INTERFACE libraries to have SOURCES.
For those with sources, add a corresponding build target to the
generated buildsystem.
Fixes: #19145
This was accidentally left out of commit 0467a2f91b (PCH: add
PRECOMPILE_HEADERS to special properties, 2015-03-12). Also add a test
case for `install(EXPORT)` and `export()` propagation of precompiled
headers.
Fixes: #19741
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`. Use `clang-format` version 6.0.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
When writing export files, correctly encode property values that contain
characters special to the CMake language parser. We must ensure that
they parse correctly when loaded on the consuming side.
Reported-by: Dan Liew <dan@su-root.co.uk>
Add properties and variables corresponding to CXX equivalents.
Add features for c_function_prototypes (C90), c_restrict (C99),
c_variadic_macros (C99) and c_static_assert (C11). This feature
set can be extended later.
Add a <PREFIX>_RESTRICT symbol define to WriteCompilerDetectionHeader
to conditionally represent the c_restrict feature.
Teach the export command to handle export sets defined by invocations
of install(TARGETS ... EXPORT foo). This makes maintenance of targets
exported to both the build tree and install tree trivial.
Introduce a policy to control the behavior.
The AliasTargets unit test already tests that using a
double-semicolon in the name is not an error. Change the ExportImport
test to use a namespace with a double-semicolon too.
