CMake 3.16 and below allow multiple `export()` calls with the same output
file even without using `APPEND`. The implementation worked by accident
by leaking memory. Refactoring in commit 5444a8095d (cmGlobalGenerator:
modernize memrory managemenbt, 2019-12-29, v3.17.0-rc1~239^2) cleaned up
that memory leak and converted it to a use-after-free instead.
The problem is caused by using the `cmGlobalGenerator::BuildExportSets`
map to own `cmExportBuildFileGenerator` instances. It can own only
one instance per output FILE name at a time, so repeating use of the
same file now frees the old `cmExportBuildFileGenerator` instance
and leaves the pointer in the `cmMakefile::ExportBuildFileGenerators`
vector dangling. Move ownership of the instances into `cmMakefile`'s
vector since its entries are not replaced on a repeat output FILE.
In future work we should introduce a policy to error out on this case.
For now simply fix the use-after-free to restore CMake <= 3.16 behavior.
Fixes: #20469
The library search paths added by commit 2746c61e6d (Swift: Add library
search paths for dependencies, 2019-06-09, v3.16.0-rc1~561^2) need to be
quoted properly on command lines to handle spaces and such. This was
already done by `cmLinkLineComputer::ComputeLinkPath` for
non-Swift-specific link directories.
The properties added by commit 4a62e3d97c (macOS: Add
OSX_COMPATIBILITY_VERSION and OSX_CURRENT_VERSION properties,
2020-01-24, v3.17.0-rc1~80^2~1) are general-purpose for all platforms
using Mach-O formats and not just on OS X. Rename them accordingly.
The properties are new to the CMake 3.17 release so we can rename
them without compatibility concerns.
Fixes: #20442
The configuration previously handled Linux properly but did not function
on macOS as `ld64` does not support `:` delimited paths. Account for
that by setting it to the empty string which will use multiple
invocations of the `-Xlinker -rpath -Xlinker ...` pattern to compute the
correct RPATH.
In commit 730a53ef1d (Help: Organize and revise 3.17 release notes,
2020-02-04, v3.17.0-rc1~21^2) we accidentally combined the release notes
for `CMAKE_XCODE_SCHEME_ENVIRONMENT` and `XCODE_SCHEME_WORKING_DIRECTORY`.
Split them up again. Also mention `CMAKE_XCODE_SCHEME_WORKING_DIRECTORY`.
Fixes: #20439
In commit 92c4c852db (Xcode: Add custom working directory property,
2019-11-18, v3.17.0-rc1~400^2) the toctree links to the new properties
were not added in sorted order. Move them.
Issue: #20439
In commit bf1e73305a (cmAlgorithms: Refactor cmRemoveDuplicates,
2019-03-03, v3.15.0-rc1~414^2) we added `union X = struct {}`.
C++ had a rule change whereby only C-compatible unnamed typedefs are
allowed. Clang 11 warns about this by default. See
https://reviews.llvm.org/D74103. The aliases don't seem to be
necessary, so simply define as structs.
In commit f5126badd8 (add_custom_command: convert DEPENDS path arguments
to absolute paths, 2019-12-18, v3.17.0-rc1~263^2) we updated the
documentation to describe the behavior introduced by that commit.
However, the behavior was removed again by commit fd0ba705ce
(add_custom_command: check if a relative path should be an in-source
path, 2020-01-09, v3.17.0-rc1~141^2~4) without updating the
documentation.
Update the documentation again to describe the behavior as of the latter
commit. Spell out the steps that `cmLocalGenerator::GetRealDependency`
and `cmTargetTraceDependencies::IsUtility` use to add file-level and
target-level dependencies.
Much like AIX, IBM i (OS identifier "OS400") implicitly adds `extern
"C"` around system header files included with the `-isystem` option.
Update the condition added by commit c688b401d3 (cmstd: Modernize CMake
system headers, 2019-08-04, v3.16.0-rc1~81^2~1) to treat `IBM i` as we
do AIX.
If cross-config mode is used, and a target depends on another target
as well as a custom command, we don't want the custom command to also
depend on the depended target, as that would build targets unnecessarily.
Fix this behavior.
Since commit 1c2d031cbd (Add -E cmake_llvm_rc to preprocess files for
llvm-rc, 2020-01-14, v3.17.0-rc1~24^2) we pass the full target `<FLAGS>`
to the llvm-rc resource compiler, but we should pass only `<DEFINES>`.
Fixes: #20414
Brad King