[llvm] [LLVM][CMake] Set LANG to "C" before linker detection. (PR #95913)

[Carlo Bramini via llvm-commits]

https://github.com/carlo-bramini updated https://github.com/llvm/llvm-project/pull/95913

>From 3fc65c5f17a64369127106db9a88709b0cd13916 Mon Sep 17 00:00:00 2001
From: Carlo Bramini <carlo_bramini at users.sourceforge.net>
Date: Tue, 18 Jun 2024 14:46:37 +0200
Subject: [PATCH] [LLVM][CMake] Set LANG to "C" before linker detection.

This PR fixes issue  #62634
---
 llvm/cmake/modules/AddLLVM.cmake | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
index 03f4e1f190fd9..53da043a61c1d 100644
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -220,8 +220,14 @@ if (NOT DEFINED LLVM_LINKER_DETECTED AND NOT WIN32)
     separate_arguments(flags UNIX_COMMAND "${CMAKE_EXE_LINKER_FLAGS}")
     set(command ${CMAKE_C_COMPILER} ${flags} ${version_flag} -o ${DEVNULL})
   endif()
+
+  # The LANG environment variable controls the way that tools use
+  # localization information, which allows to work with different
+  # national conventions.
+  # For this reason, it must be forced to a known value, otherwise
+  # the linker may reply with something different than expected.
   execute_process(
-    COMMAND ${command}
+    COMMAND ${CMAKE_COMMAND} -E env LANG=C ${command}
     OUTPUT_VARIABLE stdout
     ERROR_VARIABLE stderr
     )