[compiler-rt] ba4537b - [compiler-rt] Don't explictly ad-hoc sign dylibs on APPLE if ld is new enough

[Nico Weber via llvm-commits]

Author: Nico Weber
Date: 2022-04-13T08:35:51-04:00
New Revision: ba4537b22796a561dbcd7cd4e666bb5039510b21

URL: https://github.com/llvm/llvm-project/commit/ba4537b22796a561dbcd7cd4e666bb5039510b21
DIFF: https://github.com/llvm/llvm-project/commit/ba4537b22796a561dbcd7cd4e666bb5039510b21.diff

LOG: [compiler-rt] Don't explictly ad-hoc sign dylibs on APPLE if ld is new enough

ld64 implicitly ad-hoc code-signs as of Xcode 12, and `strip` and friends know
how keep this special ad-hoc signature valid.

So this should have no effective behavior change, except that you can now strip
libclang_rt.asan_osx_dynamic.dylib and it'll still have a valid ad-hoc
signature, instead of strip printing "warning: changes being made to the file
will invalidate the code signature in:" and making the ad-hoc code signature
invalid.

Differential Revision: https://reviews.llvm.org/D123475

Added: 
    

Modified: 
    compiler-rt/cmake/Modules/AddCompilerRT.cmake

Removed: 
    


################################################################################
diff  --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
index 062955c705332..ae6d1eaf6bb82 100644
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -372,13 +372,33 @@ function(add_compiler_rt_runtime name type)
         set_target_properties(${libname} PROPERTIES IMPORT_PREFIX "")
         set_target_properties(${libname} PROPERTIES IMPORT_SUFFIX ".lib")
       endif()
-      if(APPLE)
-        # Ad-hoc sign the dylibs
-        add_custom_command(TARGET ${libname}
-          POST_BUILD
-          COMMAND codesign --sign - $<TARGET_FILE:${libname}>
-          WORKING_DIRECTORY ${COMPILER_RT_OUTPUT_LIBRARY_DIR}
+      if (APPLE AND NOT CMAKE_LINKER MATCHES ".*lld.*")
+        # Ad-hoc sign the dylibs when using Xcode versions older than 12.
+        # Xcode 12 shipped with ld64-609.
+        # FIXME: Remove whole conditional block once everything uses Xcode 12+.
+        set(LD_V_OUTPUT)
+        execute_process(
+          COMMAND sh -c "${CMAKE_LINKER} -v 2>&1 | head -1"
+          RESULT_VARIABLE HAD_ERROR
+          OUTPUT_VARIABLE LD_V_OUTPUT
         )
+        if (HAD_ERROR)
+          message(FATAL_ERROR "${CMAKE_LINKER} failed with status ${HAD_ERROR}")
+        endif()
+        set(NEED_EXPLICIT_ADHOC_CODESIGN 1)
+        if ("${LD_V_OUTPUT}" MATCHES ".*ld64-([0-9.]+).*")
+          string(REGEX REPLACE ".*ld64-([0-9.]+).*" "\\1" HOST_LINK_VERSION ${LD_V_OUTPUT})
+          if (HOST_LINK_VERSION VERSION_GREATER_EQUAL 609)
+            set(NEED_EXPLICIT_ADHOC_CODESIGN 0)
+          endif()
+        endif()
+        if (NEED_EXPLICIT_ADHOC_CODESIGN)
+          add_custom_command(TARGET ${libname}
+            POST_BUILD
+            COMMAND codesign --sign - $<TARGET_FILE:${libname}>
+            WORKING_DIRECTORY ${COMPILER_RT_OUTPUT_LIBRARY_DIR}
+          )
+        endif()
       endif()
     endif()