When generating the `IMPORTED_CXX_MODULES_[CONFIG]` target property,
there was a missing path separator after a non-empty relative directory
part of the path to a module source file.
Co-authored-by: Brad King <brad.king@kitware.com>
Calling `install(EXPORT)` with the `CXX_MODULES_DIRECTORY` parameter
leads to installation rules being generated which `include()` CMake
scripts that set the `IMPORTED_CXX_MODULES_[CONFIG]` target property for
relevant targets. However, these scripts don't get generated for
targets in an export set which don't have any C++20 modules. When the
installation rules attempt to `include()` the missing scripts, the
install fails.
Co-authored-by: Brad King <brad.king@kitware.com>
The existing `export-interfaces-{build,install}` tests were actually
doing this, but make those test exporting the interfaces and copy the
existing tests to tests which explicitly test the "no properties"
condition.
These patches now support the `-MF` output, so remove the `none` support
added just for the old patchset which did not use it.
Also update the flag name to `-fmodule-output=`.
Due to the new Clang module mapper flag, use a new experimental support
UUID as well.
Ben Boeckel
TylerandBrad King