[compiler-rt] CompilerRT: Normalize COMPILER_RT_DEFAULT_TARGET_TRIPLE (PR #88407)

[YunQiang Su via llvm-commits]

https://github.com/wzssyqa created https://github.com/llvm/llvm-project/pull/88407

If LLVM is configured with -DLLVM_DEFAULT_TARGET_TRIPLE, and the argument is not normalized, such as Debian-style vendor-less triple, clang will try to find libclang_rt in lib/<normalized_triple>, while libclang_rt is placed into lib/<triple_arg>.

Let's also place libclang_rt into lib/<normalized_triple>.

>From a1b4b8a5544422e075f218038761dbb5bc49af45 Mon Sep 17 00:00:00 2001
From: YunQiang Su <syq at gcc.gnu.org>
Date: Fri, 12 Apr 2024 00:08:26 +0800
Subject: [PATCH] CompilerRT: Normalize COMPILER_RT_DEFAULT_TARGET_TRIPLE

If LLVM is configured with -DLLVM_DEFAULT_TARGET_TRIPLE, and the
argument is not normalized, such as Debian-style vendor-less triple,
clang will try to find libclang_rt in lib/<normalized_triple>,
while libclang_rt is placed into lib/<triple_arg>.

Let's also place libclang_rt into lib/<normalized_triple>.
---
 .../cmake/Modules/CompilerRTUtils.cmake        | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index e8e5f612d5b03c..e1d25dac9c24b7 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -362,10 +362,22 @@ macro(construct_compiler_rt_default_triple)
       message(FATAL_ERROR "CMAKE_C_COMPILER_TARGET must also be set when COMPILER_RT_DEFAULT_TARGET_ONLY is ON")
     endif()
     message(STATUS "cmake c compiler target: ${CMAKE_C_COMPILER_TARGET}")
-    set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${CMAKE_C_COMPILER_TARGET})
+    if ("${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
+      execute_process(COMMAND ${CMAKE_C_COMPILER} -target ${CMAKE_C_COMPILER_TARGET} -print-effective-triple
+                      OUTPUT_VARIABLE COMPILER_RT_DEFAULT_TARGET_TRIPLE
+                      OUTPUT_STRIP_TRAILING_WHITESPACE)
+    else()
+      set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${CMAKE_C_COMPILER_TARGET})
+    endif()
   else()
-    set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${LLVM_TARGET_TRIPLE} CACHE STRING
-          "Default triple for which compiler-rt runtimes will be built.")
+    if ("${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
+      execute_process(COMMAND ${CMAKE_C_COMPILER} -target ${LLVM_TARGET_TRIPLE} -print-effective-triple
+                      OUTPUT_VARIABLE COMPILER_RT_DEFAULT_TARGET_TRIPLE
+                      OUTPUT_STRIP_TRAILING_WHITESPACE)
+    else()
+      set(COMPILER_RT_DEFAULT_TARGET_TRIPLE ${LLVM_TARGET_TRIPLE} CACHE STRING
+            "Default triple for which compiler-rt runtimes will be built.")
+    endif()
   endif()
 
   string(REPLACE "-" ";" LLVM_TARGET_TRIPLE_LIST ${COMPILER_RT_DEFAULT_TARGET_TRIPLE})