Tweak the CMake build so that building a project just containing Clang
(and linking to an already-build LLVM) works with Xcode. The resulting
Xcode project for Clang is quite a bit smaller and builds/loads faster.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135216 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index aa89823..3ad60ea 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,7 +20,11 @@
   endif()
 
   if( NOT EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/tblgen${CMAKE_EXECUTABLE_SUFFIX}" )
-    message(FATAL_ERROR "Please set CLANG_PATH_TO_LLVM_BUILD to a directory containing a LLVM build.")
+    # Looking for bin/Debug/tblgen is a complete hack. How can we get
+    # around this?
+    if( NOT EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/Debug/tblgen${CMAKE_EXECUTABLE_SUFFIX}" )
+      message(FATAL_ERROR "Please set CLANG_PATH_TO_LLVM_BUILD to a directory containing a LLVM build.")
+    endif()
   endif()
 
   list(APPEND CMAKE_MODULE_PATH "${CLANG_PATH_TO_LLVM_BUILD}/share/llvm/cmake")
@@ -42,7 +46,12 @@
   include_directories("${PATH_TO_LLVM_BUILD}/include" "${LLVM_MAIN_INCLUDE_DIR}")
   link_directories("${PATH_TO_LLVM_BUILD}/lib")
 
-  set(LLVM_TABLEGEN_EXE "${PATH_TO_LLVM_BUILD}/bin/tblgen")
+  if( EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/tblgen${CMAKE_EXECUTABLE_SUFFIX}" )
+    set(LLVM_TABLEGEN_EXE "${PATH_TO_LLVM_BUILD}/bin/tblgen")
+  else()
+    # FIXME: This is an utter hack.
+    set(LLVM_TABLEGEN_EXE "${PATH_TO_LLVM_BUILD}/bin/Debug/tblgen")
+  endif()
 
   set( CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin )
   set( CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib )