[llvm] c4628f0 - [CMake] Disable linker version scripts for Emscripten (#221647)

[via llvm-commits]

Author: Anutosh Bhat
Date: 2026-09-13T14:03:24+05:30
New Revision: c4628f0385efd0d0d3c9d9ee0b88f89fdd4bd1f3

URL: https://github.com/llvm/llvm-project/commit/c4628f0385efd0d0d3c9d9ee0b88f89fdd4bd1f3
DIFF: https://github.com/llvm/llvm-project/commit/c4628f0385efd0d0d3c9d9ee0b88f89fdd4bd1f3.diff

LOG: [CMake] Disable linker version scripts for Emscripten (#221647)

Emscripten reports itself as a Unix-like CMake platform, causing LLVM to
set `LLVM_HAVE_LINK_VERSION_SCRIPT` and pass GNU/ELF `--version-script`
options when linking shared libraries.

Emscripten uses `wasm-ld`, which does not support GNU version scripts
and currently reports:
```
    em++: warning: ignoring unsupported linker flag: `--version-script`
```
Treat Emscripten like the other platforms without version-script
support. This prevents LLVM and Clang shared-library targets from
passing an unsupported linker option.

This was encountered while building LLVM 23.1.0 for both wasm32 and
wasm64 with Emscripten 6.x in emscripten-forge.
```
[ 45%] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExceptionSpec.cpp.o
em++: warning: ignoring unsupported linker flag: `--version-script` [-Wlinkflags]
.....
[100%] Linking CXX shared library ../../lib/libLTO.so
em++: warning: ignoring unsupported linker flag: `--version-script` [-Wlinkflags]
.....
[100%] Linking CXX shared library ../../../../lib/libclang.so
em++: warning: ignoring unsupported linker flag: `--version-script` [-Wlinkflags]
```

Added: 
    

Modified: 
    llvm/cmake/modules/HandleLLVMOptions.cmake

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index f7a0c784d997f..4ff38fbb4c09c 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -247,7 +247,7 @@ if(WIN32)
   set(LLVM_ON_UNIX 0)
 elseif(FUCHSIA OR UNIX OR CYGWIN)
   set(LLVM_ON_UNIX 1)
-  if(APPLE OR CYGWIN OR "${CMAKE_SYSTEM_NAME}" MATCHES "AIX")
+  if(APPLE OR CYGWIN OR "${CMAKE_SYSTEM_NAME}" MATCHES "AIX|Emscripten")
     set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
   else()
     set(LLVM_HAVE_LINK_VERSION_SCRIPT 1)