Compute implicit include directories from compiler output

 - CMakeParseImplicitIncludeInfo.cmake: new parser that extracts the
   compiler's include path from verbose output.  If the parser cannot
   parse the output, we fall back to the old behavior.  On osx we skip
   over framework directories (handled elsewhere).

 - CMakeDetermineCompilerABI.cmake:
     - use verbose flag in try_compile for ${src}
     - use new cmake_parse_implicit_include_info() to attempt extract
       implicit include directory path and if successful set
        CMAKE_${LANG}_IMPLICIT_INCLUDE_DIRECTORIES

 - CMakeCCompiler.cmake.in and CMakeCXXCompiler.cmake.in - preserve
   CMAKE_${LANG}_IMPLICIT_INCLUDE_DIRECTORIES value between runs in
   the same way CMAKE_${LANG}_IMPLICIT_LINK_DIRECTORIES is preserved

 - Tests/RunCMake/ParseImplicitIncludeInfo: tests for parse
   based on the older Tests/CMakeTests/ImplicitLinkInfoTest.cmake.in.
   The test runs a set of verbose compiler outputs collected from
   various machines through the parser and checks the results.  New
   compiler files can be added by dropping input/output files in the
   ParseImplicitIncludeInfo/data subdirectory and then adding the new set
   of files to the ${targets} list in ParseImplicitIncludeInfo.cmake.
   There is a helper CMakeLists.txt in ParseImplicitIncludeInfo/data
   that can help with the generation of test input files.
   NOTE: the standard cmake pre-commit hook rejects verbose compiler
   output with trailing spaces... you have to manually edit them out.
   This shouldn't impact the test.

Note that both the parser and the test code can use CMAKE_${LANG}_COMPILER_*
variables such as ${CMAKE_CXX_COMPILER_ID} to decide how to parse
verbose compiler output.  For the test code, this requires us to
save the variables values in the test input files.

Fixes: #16291

1 files changed, 1 insertions, 0 deletions

diff --git a/Modules/CMakeCXXCompiler.cmake.in b/Modules/CMakeCXXCompiler.cmake.in
index 5f52fd8..a1be02b 100644
--- a/Modules/CMakeCXXCompiler.cmake.in
+++ b/Modules/CMakeCXXCompiler.cmake.in
@@ -72,6 +72,7 @@ endif()
 @CMAKE_CXX_SYSROOT_FLAG_CODE@
 @CMAKE_CXX_OSX_DEPLOYMENT_TARGET_FLAG_CODE@
 
+set(CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES "@CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES@")
 set(CMAKE_CXX_IMPLICIT_LINK_LIBRARIES "@CMAKE_CXX_IMPLICIT_LINK_LIBRARIES@")
 set(CMAKE_CXX_IMPLICIT_LINK_DIRECTORIES "@CMAKE_CXX_IMPLICIT_LINK_DIRECTORIES@")
 set(CMAKE_CXX_IMPLICIT_LINK_FRAMEWORK_DIRECTORIES "@CMAKE_CXX_IMPLICIT_LINK_FRAMEWORK_DIRECTORIES@")