Fix implicit include directory extraction for adaptive relative paths

In some cases GCC reports *relative* implicit include directories.  They
are computed adaptively with respect to the current working directory
such that the effective implicit include directory is an unchanging
absolute path.  Teach our implicit include directory extraction to
recognize such paths and normalize them.

Fixes: #19133

1 files changed, 8 insertions, 0 deletions

diff --git a/Modules/CMakeParseImplicitIncludeInfo.cmake b/Modules/CMakeParseImplicitIncludeInfo.cmake
index c8d4c5a..c42474b 100644
--- a/Modules/CMakeParseImplicitIncludeInfo.cmake
+++ b/Modules/CMakeParseImplicitIncludeInfo.cmake
@@ -216,6 +216,14 @@ function(cmake_parse_implicit_include_info text lang dir_var log_var state_var)
       get_filename_component(dir "${d}" ABSOLUTE)
       list(APPEND implicit_dirs "${dir}")
       string(APPEND log "  collapse include dir [${d}] ==> [${dir}]\n")
+    elseif("${d}" MATCHES [[^\.\.[\/]\.\.[\/](.*)$]])
+      # This relative path is deep enough to get out of the CMakeFiles/CMakeTmp
+      # directory where the ABI check is done.  Assume that the compiler has
+      # computed this path adaptively based on the current working directory
+      # such that the effective result is absolute.
+      get_filename_component(dir "${CMAKE_BINARY_DIR}/${CMAKE_MATCH_1}" ABSOLUTE)
+      list(APPEND implicit_dirs "${dir}")
+      string(APPEND log "  collapse relative include dir [${d}] ==> [${dir}]\n")
     else()
       string(APPEND log "  skipping relative include dir [${d}]\n")
     endif()