[lld] Convert LLVM_CMAKE_PATH to a CMake path

[isuruf]

Summary

Otherwise I get the following error on windows.

CMake Error at D:/bld/lld_1569206597988/work/build/CMakeFiles/CMakeTmp/CMakeLists.txt:2 (set):
  Syntax error in cmake code at

    D:/bld/lld_1569206597988/work/build/CMakeFiles/CMakeTmp/CMakeLists.txt:2

  when parsing string

    D:\bld\lld_1569206597988\_h_env\Library\lib\cmake\llvm

  Invalid character escape '\b'.


CMake Error at D:/bld/lld_1569206597988/_build_env/Library/share/cmake-3.15/Modules/CheckSymbolExists.cmake:100 (try_compile):
  Failed to configure test project build system.
Call Stack (most recent call first):
  D:/bld/lld_1569206597988/_build_env/Library/share/cmake-3.15/Modules/CheckSymbolExists.cmake:57 (__CHECK_SYMBOL_EXISTS_IMPL)
  D:/bld/lld_1569206597988/_h_env/Library/lib/cmake/llvm/HandleLLVMOptions.cmake:943 (check_symbol_exists)
  CMakeLists.txt:56 (include)

[ori_sky]

I've stumbled upon this same issue while attempting to build lld version 12.0.0 via CMake on Windows. After applying the diff locally, I can confirm that it resolves the CMake error. This revision was submitted over a year ago so I figured I'd ping and see if it can be reviewed and merged upstream.

[ori_sky]

Pinging this as it’s been a week, and also adding some reviewers based on CODE_OWNERS.txt as I noticed the initial revision has no reviewers assigned to it.

[sbc100]

I'm not too familiar with the standalone build.. or with this cmake stuff. Would a similar patch also be needed for clang?

[isuruf]

It's already done for clang at https://github.com/llvm/llvm-project/blob/d480f968ad8b56d3ee4a6b6df5532d485b0ad01e/clang/CMakeLists.txt#L55

[isuruf]

Update patch for monorepo

[isuruf]

Is there a way to re-run the unit tests that are failing. I don't think they are related.

[ori_sky]

I can confirm the failures are unrelated -- the failing test in question appears to have been resolved in https://reviews.llvm.org/rG8a4ee3b39c149d6cf344f0804a572d5ff120bdff.

lld/CMakeLists.txt

if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   list(GET LLVM_CONFIG_OUTPUT 2 LLVM_CMAKE_PATH)
   list(GET LLVM_CONFIG_OUTPUT 3 MAIN_SRC_DIR)
 
   set(LLVM_OBJ_ROOT ${OBJ_ROOT} CACHE PATH "path to LLVM build tree")
   set(LLVM_MAIN_INCLUDE_DIR ${MAIN_INCLUDE_DIR} CACHE PATH "path to llvm/include")
   set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
 
   file(TO_CMAKE_PATH ${LLVM_OBJ_ROOT} LLVM_BINARY_DIR)
+  file(TO_CMAKE_PATH ${LLVM_CMAKE_PATH} LLVM_CMAKE_PATH)
 
   if(NOT EXISTS "${LLVM_CMAKE_PATH}/LLVMConfig.cmake")
     message(FATAL_ERROR "LLVMConfig.cmake not found")
   endif()
   include("${LLVM_CMAKE_PATH}/LLVMConfig.cmake")
 
   list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_PATH}")