[Clang] Add llvm-mt and llvm-rc to Clang bootstrap dependency

[haowei]

Summary

This patch adds llvm-mt and llvm-rc to the Clang bootstrap dependency when building the Clang under Windows so they can be used to build the Windows builtins and runtimes for the multi stage builds.

[phosek]

clang/cmake/caches/Fuchsia.cmake

42–52 ↗

(On Diff #493755)

You should be able to use the following to avoid having to separate the variables by type:

foreach(variable ${PASSTHROUGH_VARIABLES})
  get_property(is_value_set CACHE ${variable} PROPERTY VALUE SET)
  if(${is_value_set})
    get_property(value CACHE ${variable} PROPERTY VALUE)
    get_property(type CACHE ${variable} PROPERTY TYPE)
    set(BOOTSTRAP_${variable} "${value}" CACHE ${type} "")
  endif()
endforeach()

[phosek]

clang/cmake/caches/Fuchsia.cmake

20–46 ↗

(On Diff #494364)

Could we move this to a separate change since it's unrelated to the llvm-rc and llvm-mt change?

170–171 ↗

(On Diff #494364)

Could we do this in https://github.com/llvm/llvm-project/blob/98f0e4f611b40c902cb0df3ef080ae2c00e862d4/clang/CMakeLists.txt#L619? That would be more consistent with other tools such as llvm-ar.

[haowei]

clang/cmake/caches/Fuchsia.cmake

170–171 ↗

(On Diff #494364)

I add it into clang/CMakeList.txt file.
the llvm-rc and llvm-mt will only be added to bootstrap tool list on Windows. As they will be required to build Windows runtime for the bootstrap toolchain. On Linux, the runtime for the bootstrap toolchain is Linux only so they are not required.

[phosek]

LGTM but can you update the change title and description since the original one no longer matches the content of the patch.

clang/CMakeLists.txt

599–600

Nit: spelling suggestion.

603–604

Nit: I'd omit this since it doesn't provide any additional information.

clang/CMakeLists.txt

if(BOOTSTRAP_LLVM_ENABLE_LLD)
     # adding lld to clang-bootstrap-deps without having it enabled in
     # LLVM_ENABLE_PROJECTS just generates a cryptic error message.
     if (NOT "lld" IN_LIST LLVM_ENABLE_PROJECTS)
       message(FATAL_ERROR "LLD is enabled in the bootstrap build, but lld is not in LLVM_ENABLE_PROJECTS")
     endif()
     add_dependencies(clang-bootstrap-deps lld)
   endif()
 
+  if (WIN32)
+    # Build llvm-rc and llvm-mt which are needed by the Windows build.
+    add_dependencies(clang-bootstrap-deps llvm-rc)
+    if(LLVM_ENABLE_LIBXML2)
+      add_dependencies(clang-bootstrap-deps llvm-mt)
+    endif()
+  endif()
+
   # If the next stage is LTO we need to depend on LTO and possibly lld or LLVMgold
   if(BOOTSTRAP_LLVM_ENABLE_LTO OR LLVM_ENABLE_LTO AND NOT LLVM_BUILD_INSTRUMENTED)
     if(APPLE)
       add_dependencies(clang-bootstrap-deps LTO)
       # on Darwin we need to set DARWIN_LTO_LIBRARY so that -flto will work
       # using the just-built compiler, and we need to override DYLD_LIBRARY_PATH
       # so that the host object file tools will use the just-built libLTO.
       # However if System Integrity Protection is enabled the DYLD variables