Merge pull request swiftlang#832 from al45tair/eng/PR-130582819

[Linux] Enable build IDs.

Author: al45tair

CMakeLists.txt

@@ -122,6 +122,7 @@ include(CheckCSourceCompiles)
 include(CheckFunctionExists)
 include(CheckIncludeFiles)
 include(CheckLibraryExists)
+include(CheckLinkerFlag)
 include(CheckSymbolExists)
 include(GNUInstallDirs)
 include(CTest)
@@ -175,6 +176,8 @@ option(ENABLE_THREAD_LOCAL_STORAGE "enable usage of thread local storage via _Th
 set(DISPATCH_USE_THREAD_LOCAL_STORAGE ${ENABLE_THREAD_LOCAL_STORAGE})
 
 
+check_linker_flag(C "LINKER:--build-id=sha1" LINKER_SUPPORTS_BUILD_ID)
+
 check_symbol_exists(__GNU_LIBRARY__ "features.h" _GNU_SOURCE)
 if(_GNU_SOURCE)
   set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} -D_GNU_SOURCE)

src/BlocksRuntime/CMakeLists.txt

@@ -22,6 +22,10 @@ endif()
 set_target_properties(BlocksRuntime PROPERTIES
   POSITION_INDEPENDENT_CODE TRUE)
 
+if(LINKER_SUPPORTS_BUILD_ID)
+  target_link_options(BlocksRuntime PRIVATE "LINKER:--build-id=sha1")
+endif()
+
 add_library(BlocksRuntime::BlocksRuntime ALIAS BlocksRuntime)
 
 install(FILES Block.h

src/CMakeLists.txt

@@ -178,6 +178,10 @@ if(NOT CMAKE_SYSTEM_NAME MATCHES "Darwin|Windows")
   set_target_properties(dispatch PROPERTIES INSTALL_RPATH "$ORIGIN")
 endif()
 
+if(LINKER_SUPPORTS_BUILD_ID)
+  target_link_options(dispatch PRIVATE "LINKER:--build-id=sha1")
+endif()
+
 if(ENABLE_SWIFT)
   add_subdirectory(swift)
 endif()