From ebcf4c44a9b1937a2236a41fab5e7a0974285288 Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Thu, 7 Nov 2024 16:46:17 +0100
Subject: [PATCH] [cmake,gcc,clang] use -fmacro-prefix-map and
 -ffile-prefix-map

Instead of some bash path substitution only working with Makefiles use
the compiler options to map source and build directories to some
defaults
---
 CMakeLists.txt               | 12 ------------
 cmake/CXXCompilerFlags.cmake |  5 +++++
 cmake/CompilerFlags.cmake    |  6 +++++-
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ea5a2513d..faaeef6db 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -239,18 +239,6 @@ if(CMAKE_COMPILER_IS_GNUCC)
 	endif()
 endif()
 
-# When building with Unix Makefiles and doing any release builds
-# try to set __FILE__ to relative paths via a make specific macro
-if (CMAKE_GENERATOR MATCHES "Unix Makefile*")
-	if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
-		string(TOUPPER ${CMAKE_BUILD_TYPE} UPPER_BUILD_TYPE)
-		CHECK_C_COMPILER_FLAG (-Wno-builtin-macro-redefined Wno-builtin-macro-redefined)
-		if(Wno-builtin-macro-redefined)
-			set(CMAKE_C_FLAGS_${UPPER_BUILD_TYPE} "${CMAKE_C_FLAGS_${UPPER_BUILD_TYPE}} -Wno-builtin-macro-redefined -D__FILE__='\"$(subst ${PROJECT_BINARY_DIR}/,,$(subst ${PROJECT_SOURCE_DIR}/,,$(abspath $<)))\"'")
-		endif()
-	endif()
-endif()
-
 if(CMAKE_COMPILER_IS_CLANG)
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-c11-extensions -Wno-gnu")
 endif()
diff --git a/cmake/CXXCompilerFlags.cmake b/cmake/CXXCompilerFlags.cmake
index 95bc64cdc..39755a244 100644
--- a/cmake/CXXCompilerFlags.cmake
+++ b/cmake/CXXCompilerFlags.cmake
@@ -61,6 +61,11 @@ if (ENABLE_WARNING_ERROR)
 	CheckCXXFlag(-Werror)
 endif()
 
+CheckCXXFlag(-fmacro-prefix-map="${CMAKE_SOURCE_DIR}"="./")
+CheckCXXFlag(-fmacro-prefix-map="${CMAKE_BINARY_DIR}"="./build/")
+CheckCXXFlag(-ffile-prefix-map="${CMAKE_SOURCE_DIR}"="./")
+CheckCXXFlag(-ffile-prefix-map="${CMAKE_BINARY_DIR}"="./build")
+
 # https://stackoverflow.com/questions/4913922/possible-problems-with-nominmax-on-visual-c
 if (WIN32)
     add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-DNOMINMAX>)
diff --git a/cmake/CompilerFlags.cmake b/cmake/CompilerFlags.cmake
index 682aa7dd3..ed553c4b6 100644
--- a/cmake/CompilerFlags.cmake
+++ b/cmake/CompilerFlags.cmake
@@ -52,10 +52,14 @@ if (ENABLE_WARNING_VERBOSE)
 	endforeach()
 endif()
 
-
 if (ENABLE_WARNING_ERROR)
 	CheckCFlag(-Werror)
 endif()
 
+CheckCFlag(-fmacro-prefix-map="${CMAKE_SOURCE_DIR}"="./")
+CheckCFlag(-fmacro-prefix-map="${CMAKE_BINARY_DIR}"="./build/")
+CheckCFlag(-ffile-prefix-map="${CMAKE_SOURCE_DIR}"="./")
+CheckCFlag(-ffile-prefix-map="${CMAKE_BINARY_DIR}"="./build")
+
 set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} CACHE STRING "default CFLAGS")
 message("Using CFLAGS ${CMAKE_C_FLAGS}")