Append an executable suffix to the toolchain tool paths on Windows platform.

[vvereschaka]

Summary

Append a default CMake suffix (CMAKE_EXECUTABLE_SUFFIX) for the build host to the toolchain tool path when adding a LLVM external project. The tool binary files should contain .exe suffix to run them properly on Windows platform when building the projects.

[phosek]

LGTM

llvm/trunk/cmake/modules/LLVMExternalProjectUtils.cmake

foreach(arg ${ARG_CMAKE_ARGS})
     if(arg MATCHES "^-DCMAKE_SYSTEM_NAME=")
       string(REGEX REPLACE "^-DCMAKE_SYSTEM_NAME=(.*)$" "\\1" _cmake_system_name "${arg}")
     endif()
   endforeach()
 
   if(ARG_USE_TOOLCHAIN AND NOT CMAKE_CROSSCOMPILING)
     if(CLANG_IN_TOOLCHAIN)
       if(_cmake_system_name STREQUAL Windows)
-        set(compiler_args -DCMAKE_C_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang-cl
-                          -DCMAKE_CXX_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang-cl)
+        set(compiler_args -DCMAKE_C_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang-cl${CMAKE_EXECUTABLE_SUFFIX}
+                          -DCMAKE_CXX_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang-cl${CMAKE_EXECUTABLE_SUFFIX})
       else()
-        set(compiler_args -DCMAKE_C_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang
-                          -DCMAKE_CXX_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang++)
+        set(compiler_args -DCMAKE_C_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang${CMAKE_EXECUTABLE_SUFFIX}
+                          -DCMAKE_CXX_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang++${CMAKE_EXECUTABLE_SUFFIX})
       endif()
     endif()
     if(lld IN_LIST TOOLCHAIN_TOOLS)
       if(_cmake_system_name STREQUAL Windows)
-        list(APPEND compiler_args -DCMAKE_LINKER=${LLVM_RUNTIME_OUTPUT_INTDIR}/lld-link)
+        list(APPEND compiler_args -DCMAKE_LINKER=${LLVM_RUNTIME_OUTPUT_INTDIR}/lld-link${CMAKE_EXECUTABLE_SUFFIX})
       else()
-        list(APPEND compiler_args -DCMAKE_LINKER=${LLVM_RUNTIME_OUTPUT_INTDIR}/ld.lld)
+        list(APPEND compiler_args -DCMAKE_LINKER=${LLVM_RUNTIME_OUTPUT_INTDIR}/ld.lld${CMAKE_EXECUTABLE_SUFFIX})
       endif()
     endif()
     if(llvm-ar IN_LIST TOOLCHAIN_TOOLS)
-      list(APPEND compiler_args -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar)
+      list(APPEND compiler_args -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar${CMAKE_EXECUTABLE_SUFFIX})
     endif()
     if(llvm-ranlib IN_LIST TOOLCHAIN_TOOLS)
-      list(APPEND compiler_args -DCMAKE_RANLIB=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ranlib)
+      list(APPEND compiler_args -DCMAKE_RANLIB=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ranlib${CMAKE_EXECUTABLE_SUFFIX})
     endif()
     if(llvm-nm IN_LIST TOOLCHAIN_TOOLS)
-      list(APPEND compiler_args -DCMAKE_NM=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-nm)
+      list(APPEND compiler_args -DCMAKE_NM=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-nm${CMAKE_EXECUTABLE_SUFFIX})
     endif()
     if(llvm-objdump IN_LIST TOOLCHAIN_TOOLS)
-      list(APPEND compiler_args -DCMAKE_OBJDUMP=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-objdump)
+      list(APPEND compiler_args -DCMAKE_OBJDUMP=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-objdump${CMAKE_EXECUTABLE_SUFFIX})
     endif()
     if(llvm-objcopy IN_LIST TOOLCHAIN_TOOLS)
-      list(APPEND compiler_args -DCMAKE_OBJCOPY=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-objcopy)
+      list(APPEND compiler_args -DCMAKE_OBJCOPY=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-objcopy${CMAKE_EXECUTABLE_SUFFIX})
     endif()
     if(llvm-strip IN_LIST TOOLCHAIN_TOOLS AND NOT ARG_STRIP_TOOL)
-      list(APPEND compiler_args -DCMAKE_STRIP=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-strip)
+      list(APPEND compiler_args -DCMAKE_STRIP=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-strip${CMAKE_EXECUTABLE_SUFFIX})
     endif()
     list(APPEND ARG_DEPENDS ${TOOLCHAIN_TOOLS})
   endif()
 
   if(ARG_STRIP_TOOL)
     list(APPEND compiler_args -DCMAKE_STRIP=${ARG_STRIP_TOOL})
   endif()