[clang] 9175dd9 - [CMake] Detect properly new linker introduced in Xcode 15 (#77806)

[via cfe-commits]

Author: Eric Miotto
Date: 2024-01-19T16:32:32-05:00
New Revision: 9175dd9cbcad01a47acea9f1b99a0c96bf1a9a29

URL: https://github.com/llvm/llvm-project/commit/9175dd9cbcad01a47acea9f1b99a0c96bf1a9a29
DIFF: https://github.com/llvm/llvm-project/commit/9175dd9cbcad01a47acea9f1b99a0c96bf1a9a29.diff

LOG: [CMake] Detect properly new linker introduced in Xcode 15 (#77806)

As explained in [1], this linker is functionally equivalent to the
classic one (`ld64`) for build system purposes -- in particular to 
enable the use of order files to link `clang`. For this reason, in 
addition to fixing the detection rename `LLVM_LINKER_IS_LD64` to 
`LLVM_LINKER_IS_APPLE` to make the result of such detection more 
clear -- this should not cause any issue to downstream users, from 
a quick search in SourceGraph [2], only Swift uses the value of
this variable (which I will take care of updating in due time).

[1]: https://developer.apple.com/documentation/xcode-release-notes/xcode-15-release-notes#Linking
[2]: https://sourcegraph.com/search?q=context:global+LLVM_LINKER_IS_LD64+lang:cmake+fork:no+-file:AddLLVM.cmake+-file:clang/tools/driver/CMakeLists.txt&patternType=standard&sm=1&groupBy=repo
rdar://120740222

Added: 
    

Modified: 
    clang/tools/driver/CMakeLists.txt
    llvm/cmake/modules/AddLLVM.cmake

Removed: 
    


################################################################################
diff  --git a/clang/tools/driver/CMakeLists.txt b/clang/tools/driver/CMakeLists.txt
index 2182486f93a555..d70b92b0984e52 100644
--- a/clang/tools/driver/CMakeLists.txt
+++ b/clang/tools/driver/CMakeLists.txt
@@ -103,10 +103,10 @@ if (APPLE)
 endif()
 
 if(CLANG_ORDER_FILE AND
-    (LLVM_LINKER_IS_LD64 OR LLVM_LINKER_IS_GOLD OR LLVM_LINKER_IS_LLD))
+    (LLVM_LINKER_IS_APPLE OR LLVM_LINKER_IS_GOLD OR LLVM_LINKER_IS_LLD))
   include(LLVMCheckLinkerFlag)
 
-  if (LLVM_LINKER_IS_LD64 OR (LLVM_LINKER_IS_LLD AND APPLE))
+  if (LLVM_LINKER_IS_APPLE OR (LLVM_LINKER_IS_LLD AND APPLE))
     set(LINKER_ORDER_FILE_OPTION "-Wl,-order_file,${CLANG_ORDER_FILE}")
   elseif (LLVM_LINKER_IS_GOLD)
     set(LINKER_ORDER_FILE_OPTION "-Wl,--section-ordering-file,${CLANG_ORDER_FILE}")

diff  --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
index 14c0837c35964d..5e989618552824 100644
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -211,10 +211,10 @@ if (NOT DEFINED LLVM_LINKER_DETECTED AND NOT WIN32)
     )
 
   if(APPLE)
-    if("${stderr}" MATCHES "PROJECT:ld64")
+    if("${stderr}" MATCHES "PROGRAM:ld")
       set(LLVM_LINKER_DETECTED YES CACHE INTERNAL "")
-      set(LLVM_LINKER_IS_LD64 YES CACHE INTERNAL "")
-      message(STATUS "Linker detection: ld64")
+      set(LLVM_LINKER_IS_APPLE YES CACHE INTERNAL "")
+      message(STATUS "Linker detection: Apple")
     elseif("${stderr}" MATCHES "^LLD" OR
            "${stdout}" MATCHES "^LLD")
       set(LLVM_LINKER_DETECTED YES CACHE INTERNAL "")