[cmake] Support moving debuginfo-tests to llvm/projects

[hintonda]

Summary

Support moving debuginfo-tests to llvm/projects

---

(see D40971)
This is one of two independent patches designed to support moving the
debuginfo-test repo from clang/test to llvm/projects. While each
patch is completely independent and can be applied seperately, both
are required to actually move the repo.

Due to the independent nature of these patches, debuginfo-test can
coexist in both clang/test and llvm/projects, so testers can add
debuginfo-test to llvm/projects without the need to immediately remove
it from clang/test.

Once both patches land and all buildbots have moved debuginfo-test to
llvm/projects, llvm/utils/test-debuginfo.pl can be removed as well the
tools reference to it in clang/test/lit.cfg.py. At which point, only
llvm/projects will be supported.

[hintonda]

• Simply diff.

CMakeLists.txt

if(DYLD_LIBRARY_PATH)
     endforeach()
   endif()
 endif()
 
 # Side-by-side subprojects layout: automatically set the
 # LLVM_EXTERNAL_${project}_SOURCE_DIR using LLVM_ALL_PROJECTS
 # This allows an easy way of setting up a build directory for llvm and another
 # one for llvm+clang+... using the same sources.
-set(LLVM_ALL_PROJECTS "clang;libcxx;libcxxabi;lldb;compiler-rt;lld;polly")
+set(LLVM_ALL_PROJECTS "clang;libcxx;libcxxabi;lldb;compiler-rt;lld;polly,debuginfo-tests")
 set(LLVM_ENABLE_PROJECTS "" CACHE STRING
   "Semicolon-separated list of projects to build (${LLVM_ALL_PROJECTS}), or \"all\".")
 if( LLVM_ENABLE_PROJECTS STREQUAL "all" )
   set( LLVM_ENABLE_PROJECTS ${LLVM_ALL_PROJECTS})
 endif()
 foreach(proj ${LLVM_ENABLE_PROJECTS})
   set(PROJ_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../${proj}")
   if(NOT EXISTS "${PROJ_DIR}" OR NOT IS_DIRECTORY "${PROJ_DIR}")
if( LLVM_INCLUDE_RUNTIMES )
   add_subdirectory(runtimes)
 endif()
 
 if( LLVM_INCLUDE_EXAMPLES )
   add_subdirectory(examples)
 endif()
 
 if( LLVM_INCLUDE_TESTS )
-  if(EXISTS ${LLVM_MAIN_SRC_DIR}/projects/test-suite AND TARGET clang)
+  if(TARGET clang)
+    if(EXISTS ${LLVM_MAIN_SRC_DIR}/projects/test-suite)
       include(LLVMExternalProjectUtils)
       llvm_ExternalProject_Add(test-suite ${LLVM_MAIN_SRC_DIR}/projects/test-suite
         USE_TOOLCHAIN
         EXCLUDE_FROM_ALL
         NO_INSTALL
         ALWAYS_CLEAN)
     endif()
+    add_llvm_external_project(debuginfo-tests projects/debuginfo-tests)
+  endif()
   add_subdirectory(utils/lit)
   add_subdirectory(test)
   add_subdirectory(unittests)
   if( LLVM_INCLUDE_UTILS )
     add_subdirectory(utils/unittest)
   endif()
 
   if (WIN32)

projects/CMakeLists.txt

 # Discover the projects that use CMake in the subdirectories.
 # Note that explicit cmake invocation is required every time a new project is
 # added or removed.
 file(GLOB entries *)
 foreach(entry ${entries})
   if(IS_DIRECTORY ${entry} AND EXISTS ${entry}/CMakeLists.txt)
     if((NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/dragonegg) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/libcxx) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/libcxxabi) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/libunwind) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/test-suite) AND
+       (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/debuginfo-tests) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/parallel-libs) AND
        (NOT ${entry} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR}/openmp))
       add_subdirectory(${entry})
     endif()
   endif()
 endforeach(entry)
 
 # Also add in libc++ and compiler-rt trees if present (and we have

utils/lit/lit/llvm/config.py

def use_clang(self, required=True):
         # an already installed llvm.
         if self.config.host_triple and self.config.host_triple != '@LLVM_HOST_TRIPLE@':
             self.config.substitutions.append(('%target_itanium_abi_host_triple',
                                               '--target=%s' % self.make_itanium_abi_triple(self.config.host_triple)))
         else:
             self.config.substitutions.append(
                 ('%target_itanium_abi_host_triple', ''))
 
+        clang_src_dir = getattr(self.config, 'clang_src_dir', None)
+        if clang_src_dir:
             self.config.substitutions.append(
-            ('%src_include_dir', self.config.clang_src_dir + '/include'))
+                ('%src_include_dir', os.path.join(clang_src_dir, 'include')))
 
         # FIXME: Find nicer way to prohibit this.
         self.config.substitutions.append(
             (' clang ', """*** Do not use 'clang' in tests, use '%clang'. ***"""))
         self.config.substitutions.append(
             (' clang\+\+ ', """*** Do not use 'clang++' in tests, use '%clangxx'. ***"""))
         self.config.substitutions.append(
             (' clang-cc ',