[CMake] Remove SetTargetTriple (#66464)

This module is only used in two places and its logic can be inlined and
simplified.

Author: petrhosek

llvm/CMakeLists.txt

@@ -875,16 +875,19 @@ include(config-ix)
 # invocation time. Except on 64-bit AIX, where the system toolchain
 # expect 32-bit objects by default.
 if("${LLVM_HOST_TRIPLE}" MATCHES "^powerpc64-ibm-aix")
-  string(REGEX REPLACE "^powerpc64" "powerpc" LLVM_DEFAULT_TARGET_TRIPLE_default "${LLVM_HOST_TRIPLE}")
+  string(REGEX REPLACE "^powerpc64" "powerpc" LLVM_DEFAULT_TARGET_TRIPLE_DEFAULT "${LLVM_HOST_TRIPLE}")
 else()
   # Only set default triple when native target is enabled.
   if (LLVM_NATIVE_TARGET)
-    set(LLVM_DEFAULT_TARGET_TRIPLE_default "${LLVM_HOST_TRIPLE}")
+    set(LLVM_DEFAULT_TARGET_TRIPLE_DEFAULT "${LLVM_HOST_TRIPLE}")
   endif()
 endif()
 
-include(SetTargetTriple)
-set_llvm_target_triple()
+set(LLVM_DEFAULT_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE_DEFAULT}" CACHE STRING
+    "Default target for which LLVM will generate code." )
+message(STATUS "LLVM default target triple: ${LLVM_DEFAULT_TARGET_TRIPLE}")
+
+set(LLVM_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}")
 
 if(WIN32 OR CYGWIN)
   if(BUILD_SHARED_LIBS OR LLVM_BUILD_LLVM_DYLIB)

llvm/cmake/config-ix.cmake

@@ -461,6 +461,7 @@ get_host_triple(LLVM_INFERRED_HOST_TRIPLE)
 
 set(LLVM_HOST_TRIPLE "${LLVM_INFERRED_HOST_TRIPLE}" CACHE STRING
     "Host on which LLVM binaries will run")
+message(STATUS "LLVM host triple: ${LLVM_HOST_TRIPLE}")
 
 # Determine the native architecture.
 string(TOLOWER "${LLVM_TARGET_ARCH}" LLVM_NATIVE_ARCH)

llvm/cmake/modules/SetTargetTriple.cmake

@@ -160,8 +160,15 @@ find_package(Python3 REQUIRED COMPONENTS Interpreter)
 # Host triple is used by tests to check if they are running natively.
 include(GetHostTriple)
 get_host_triple(LLVM_HOST_TRIPLE)
+message(STATUS "LLVM host triple: ${LLVM_HOST_TRIPLE}")
+
+# TODO: We shouldn't be using LLVM_DEFAULT_TARGET_TRIPLE for runtimes since we
+# aren't generating code, LLVM_TARGET_TRIPLE is a better fit.
 set(LLVM_DEFAULT_TARGET_TRIPLE "${LLVM_HOST_TRIPLE}" CACHE STRING
-  "Default target for which the runtimes will be built.")
+    "Default target for which the runtimes will be built.")
+message(STATUS "LLVM default target triple: ${LLVM_DEFAULT_TARGET_TRIPLE}")
+
+set(LLVM_TARGET_TRIPLE "${LLVM_DEFAULT_TARGET_TRIPLE}")
 
 option(LLVM_INCLUDE_TESTS "Generate build targets for the runtimes unit tests." ON)
 option(LLVM_INCLUDE_DOCS "Generate build targets for the runtimes documentation." ON)
@@ -175,9 +182,6 @@ endif()
 # This can be used to detect whether we're in the runtimes build.
 set(LLVM_RUNTIMES_BUILD ON)
 
-include(SetTargetTriple)
-set_llvm_target_triple()
-
 foreach(entry ${runtimes})
   get_filename_component(projName ${entry} NAME)