[CMake] Provide an option to use relative paths in debug info

CMake always uses absolute file paths in the generated compiler
invocation which results in absolute file paths being embedded in debug
info. This is undesirable when building a toolchain e.g. on bots as the
debug info may embed the bot source checkout path which is meaningless
anywhere else.

This change introduces the LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO which uses
-fdebug-prefix-map (where supported) options to rewrite paths embedded
into debug info with relative ones. Additionally, LLVM_SOURCE_PREFIX can
be used to override the path to source directory with a different one.

Differential Revision: https://reviews.llvm.org/D62622

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@362185 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/cmake/caches/Fuchsia-stage2.cmake b/cmake/caches/Fuchsia-stage2.cmake
index cedc69fa6f6e195a44bb32adaaef7f4da0936162..100a9b164e5eac6329f435567978ed63fea0f92e 100644 (file)
--- a/cmake/caches/Fuchsia-stage2.cmake
+++ b/cmake/caches/Fuchsia-stage2.cmake
@@ -15,6 +15,7 @@ set(LLVM_ENABLE_ZLIB ON CACHE BOOL "")
 set(LLVM_EXTERNALIZE_DEBUGINFO ON CACHE BOOL "")
 set(LLVM_INCLUDE_EXAMPLES OFF CACHE BOOL "")
 set(LLVM_INCLUDE_DOCS OFF CACHE BOOL "")
+set(LLVM_USE_RELATIVE_PATHS_IN_DEBUG_INFO ON CACHE BOOL "")
 
 set(CLANG_DEFAULT_CXX_STDLIB libc++ CACHE STRING "")
 if(NOT APPLE)