[clang] [compiler-rt] [llvm] [CMake] Use Clang to infer the target triple (PR #89425)

[YunQiang Su via llvm-commits]

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@@ -181,6 +181,20 @@ message(STATUS "LLVM default target triple: ${LLVM_DEFAULT_TARGET_TRIPLE}")
 
 set(LLVM_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}")
 
+if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
+  set(print_target_triple ${CMAKE_CXX_COMPILER} --target=${LLVM_RUNTIME_TRIPLE} -print-target-triple)
+  execute_process(COMMAND ${print_target_triple}
+    RESULT_VARIABLE result
+    OUTPUT_VARIABLE output
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  if(result EQUAL 0)
+    set(LLVM_RUNTIME_TRIPLE ${output})
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wzssyqa wrote:

`LLVM_RUNTIME_TRIPLE` seem to be not used? I cannot find this symbol by `grep`.

https://github.com/llvm/llvm-project/pull/89425