CMake: Fix stand-alone clang builds since r353268

[tstellar]

Summary

Handle the case where LLVM_MAIN_SRC_DIR is not set and also use
LLVM_CMAKE_DIR for locating installed cmake files rather than
LLVM_CMAKE_PATH.

[phosek]

LGTM

[smeenai]

clang/lib/Basic/CMakeLists.txt

13 ↗

(On Diff #186726)

Will this work when using llvm-config instead of LLVM's CMake package?

[andrewrk]

I confirm this solves the issue.

llvm/cmake/modules/AddLLVM.cmake

1739 ↗

(On Diff #186726)

I think ${path} should still be quoted here for best practice, as well as ${GIT_EXECUTABLE} above.

1745 ↗

(On Diff #186726)

these variables should be quoted too

[tstellar]

clang/lib/Basic/CMakeLists.txt

13 ↗

(On Diff #186726)

I will test this and a few other configurations to make sure.

[smeenai]

This could also be improved by teaching clang to use LLVM_BUILD_MAIN_SRC_DIR when that's available.

[tstellar]

Updated patch to fix non-standalone builds. There is more refactoring
that could be done, but this at least restores functionality to before
r353268.

I have tested non-standalone builds and standalone builds with and
without llvm-config.

[smeenai]

LGTM. There's more clean up that could be done here, but this addresses the immediate issue. Thanks!

cfe/trunk/CMakeLists.txt

if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
   # LLVM_CONFIG.
   if (NOT LLVM_CONFIG_FOUND)
     # Pull values from LLVMConfig.cmake.  We can drop this once the llvm-config
     # path is removed.
     set(TOOLS_BINARY_DIR ${LLVM_TOOLS_BINARY_DIR})
     set(LIBRARY_DIR ${LLVM_LIBRARY_DIR})
     set(INCLUDE_DIR ${LLVM_INCLUDE_DIR})
     set(LLVM_OBJ_DIR ${LLVM_BINARY_DIR})
+    # The LLVM_CMAKE_PATH variable is set when doing non-standalone builds and
+    # used in this project, so we need to make sure we set this value.
+    # FIXME: LLVM_CMAKE_DIR comes from LLVMConfig.cmake.  We should rename
+    # LLVM_CMAKE_PATH to LLVM_CMAKE_DIR throughout the project.
+    set(LLVM_CMAKE_PATH ${LLVM_CMAKE_DIR})
   endif()
 
   set(LLVM_TOOLS_BINARY_DIR ${TOOLS_BINARY_DIR} CACHE PATH "Path to llvm/bin")
   set(LLVM_LIBRARY_DIR ${LIBRARY_DIR} CACHE PATH "Path to llvm/lib")
   set(LLVM_MAIN_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
   set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
   set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
 

llvm/trunk/cmake/modules/AddLLVM.cmake

function(setup_dependency_debugging name)
   set(deny_attributes_inc "(deny file* (literal \"${LLVM_BINARY_DIR}/include/llvm/IR/Attributes.inc\"))")
   set(deny_intrinsics_inc "(deny file* (literal \"${LLVM_BINARY_DIR}/include/llvm/IR/Intrinsics.inc\"))")
 
   set(sandbox_command "sandbox-exec -p '(version 1) (allow default) ${deny_attributes_inc} ${deny_intrinsics_inc}'")
   set_target_properties(${name} PROPERTIES RULE_LAUNCH_COMPILE ${sandbox_command})
 endfunction()
 
 function(find_first_existing_vc_file path out_var)
+  if(NOT EXISTS "${path}")
+    return()
+  endif()
   if(EXISTS "${path}/.svn")
     set(svn_files
       "${path}/.svn/wc.db"   # SVN 1.7
       "${path}/.svn/entries" # SVN 1.6
     )
     foreach(file IN LISTS svn_files)
       if(EXISTS "${file}")
         set(${out_var} "${file}" PARENT_SCOPE)