make precompiled header compilation depend on the actual compiler executable

CMake/cotire.cmake

@@ -2206,14 +2206,18 @@ function (cotire_setup_pch_file_compilation _language _target _targetScript _pre
 			else()
 				file (RELATIVE_PATH _pchFileLogPath "${CMAKE_BINARY_DIR}" "${_pchFile}")
 			endif()
+			# make precompiled header compilation depend on the actual compiler executable to force
+			# re-compilation when the compiler executable is updated. This prevents "created by a different GCC executable"
+			# warnings when the precompiled header is included.
+			get_filename_component(_realCompilerExe "${CMAKE_${_language}_COMPILER}" ABSOLUTE)
 			if (COTIRE_DEBUG)
-				message (STATUS "add_custom_command: OUTPUT ${_pchFile} ${_cmds} DEPENDS ${_prefixFile} IMPLICIT_DEPENDS ${_language} ${_prefixFile}")
+				message (STATUS "add_custom_command: OUTPUT ${_pchFile} ${_cmds} DEPENDS ${_prefixFile} ${_realCompilerExe} IMPLICIT_DEPENDS ${_language} ${_prefixFile}")
 			endif()
 			set_property (SOURCE "${_pchFile}" PROPERTY GENERATED TRUE)
 			add_custom_command(
 				OUTPUT "${_pchFile}"
 				COMMAND ${_cmds}
-				DEPENDS "${_prefixFile}"
+				DEPENDS "${_prefixFile}" "${_realCompilerExe}"
 				IMPLICIT_DEPENDS ${_language} "${_prefixFile}"
 				WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
 				COMMENT "Building ${_language} precompiled header ${_pchFileLogPath}"