[Bf-blender-cvs] [1daa3c3f0a1] master: Clang/GCC: use relative path in __FILE__ macro

[Ankit Meel]

Commit: 1daa3c3f0a1cfd74bef527e0207f38154e591d46
Author: Ankit Meel
Date:   Mon Nov 2 15:10:10 2020 +0530
Branches: master
https://developer.blender.org/rB1daa3c3f0a1cfd74bef527e0207f38154e591d46

Clang/GCC: use relative path in __FILE__ macro

This change removes the user-specific information from
macros like `__FILE__` and keeps it relative to top level
source or build (for generated files) directory.
It makes traces concise.

Added option `WITH_COMPILER_SHORT_FILE_MACRO` enabled by default.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D9386

===================================================================

M	CMakeLists.txt

===================================================================

diff --git a/CMakeLists.txt b/CMakeLists.txt
index eb04da749ab..9c5ab607bf6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -570,6 +570,11 @@ if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
   endif()
 endif()
 
+if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+  option(WITH_COMPILER_SHORT_FILE_MACRO "Make paths in macros like __FILE__ relative to top level source and build directories." ON)
+  mark_as_advanced(WITH_COMPILER_SHORT_FILE_MACRO)
+endif()
+
 if(WIN32)
   # Use hardcoded paths or find_package to find externals
   option(WITH_WINDOWS_FIND_MODULES "Use find_package to locate libraries" OFF)
@@ -1655,6 +1660,38 @@ if(UNIX AND NOT APPLE)
   endif()
 endif()
 
+if(WITH_COMPILER_SHORT_FILE_MACRO)
+  # Use '-fmacro-prefix-map' for Clang and GCC (MSVC doesn't support this).
+  if((CMAKE_COMPILER_IS_GNUCC AND CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 8.4) OR
+     (CMAKE_C_COMPILER_ID STREQUAL "Clang" AND CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10.0) OR
+     (CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0)
+  )
+
+    if(APPLE)
+      if(XCODE AND ${XCODE_VERSION} VERSION_LESS 12.0)
+      # Developers may have say LLVM Clang-10.0.1 toolchain with Xcode-11.
+        message_first_run(WARNING
+          "-fmacro-prefix-map flag is NOT supported by Clang shipped with Xcode-${XCODE_VERSION}."
+          " Some Xcode functionality in Product menu may not work. Disabling WITH_COMPILER_SHORT_FILE_MACRO."
+        )
+        set(WITH_COMPILER_SHORT_FILE_MACRO OFF)
+      endif()
+    endif()
+    if(WITH_COMPILER_SHORT_FILE_MACRO)
+      set(PLATFORM_CFLAGS "${PLATFORM_CFLAGS} \
+-fmacro-prefix-map=\"${CMAKE_SOURCE_DIR}/\"=\"\" \
+-fmacro-prefix-map=\"${CMAKE_BINARY_DIR}/\"=\"\""
+      )
+    endif()
+  else()
+    message_first_run(WARNING
+      "-fmacro-prefix-map flag is NOT supported by ${CMAKE_C_COMPILER_ID} version-${CMAKE_C_COMPILER_VERSION}."
+      " Disabling WITH_COMPILER_SHORT_FILE_MACRO."
+    )
+    set(WITH_COMPILER_SHORT_FILE_MACRO OFF)
+  endif()
+endif()
+
 # Include warnings first, so its possible to disable them with user defined flags
 # eg: -Wno-uninitialized
 set(CMAKE_C_FLAGS "${C_WARNINGS} ${CMAKE_C_FLAGS} ${PLATFORM_CFLAGS}")