CMake: Don't look for llvm-tblgen when building outside LLVM tree

Previously, the CMake build would look for llvm-tblgen to determine
if a directory is an LLVM build or install directory. Since we don't
want to include llvm-tblgen in the install, look for llvm-config instead,
and use that to find llvm-tblgen.

Differential Revision: http://llvm-reviews.chandlerc.com/D1483

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189127 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/CMakeLists.txt b/CMakeLists.txt
index eb0b0a7737dfd7864541d4670b1b0c6ebd08c3b9..386f3e714250fa40b11b8f178779c642ae8f7fd5 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,12 +19,14 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
     endif()
   endif()
 
-  if( NOT EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/llvm-tblgen${CMAKE_EXECUTABLE_SUFFIX}" )
-    # Looking for bin/Debug/llvm-tblgen is a complete hack. How can we get
+  if (EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/llvm-config${CMAKE_EXECUTABLE_SUFFIX}")
+    set (PATH_TO_LLVM_CONFIG "${CLANG_PATH_TO_LLVM_BUILD}/bin/llvm-config${CMAKE_EXECUTABLE_SUFFIX}")
+  elseif (EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/Debug/llvm-config${CMAKE_EXECUTABLE_SUFFIX}")
+    # Looking for bin/Debug/llvm-config is a complete hack. How can we get
     # around this?
-    if( NOT EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/Debug/llvm-tblgen${CMAKE_EXECUTABLE_SUFFIX}" )
-      message(FATAL_ERROR "Please set CLANG_PATH_TO_LLVM_BUILD to a directory containing a LLVM build.")
-    endif()
+    set (PATH_TO_LLVM_CONFIG "${CLANG_PATH_TO_LLVM_BUILD}/bin/Debug/llvm-config${CMAKE_EXECUTABLE_SUFFIX}")
+  else()
+    message(FATAL_ERROR "Please set CLANG_PATH_TO_LLVM_BUILD to a directory containing a LLVM build.")
   endif()
 
   list(APPEND CMAKE_MODULE_PATH "${CLANG_PATH_TO_LLVM_BUILD}/share/llvm/cmake")
@@ -46,12 +48,8 @@ if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )
   include_directories("${PATH_TO_LLVM_BUILD}/include" "${LLVM_MAIN_INCLUDE_DIR}")
   link_directories("${PATH_TO_LLVM_BUILD}/lib")
 
-  if( EXISTS "${CLANG_PATH_TO_LLVM_BUILD}/bin/llvm-tblgen${CMAKE_EXECUTABLE_SUFFIX}" )
-    set(LLVM_TABLEGEN_EXE "${PATH_TO_LLVM_BUILD}/bin/llvm-tblgen${CMAKE_EXECUTABLE_SUFFIX}")
-  else()
-    # FIXME: This is an utter hack.
-    set(LLVM_TABLEGEN_EXE "${PATH_TO_LLVM_BUILD}/bin/Debug/llvm-tblgen${CMAKE_EXECUTABLE_SUFFIX}")
-  endif()
+  exec_program("${PATH_TO_LLVM_CONFIG} --bindir" OUTPUT_VARIABLE LLVM_TABLEGEN_EXE)
+  set(LLVM_TABLEGEN_EXE "${LLVM_TABLEGEN_EXE}/llvm-tblgen${CMAKE_EXECUTABLE_SUFFIX}")
 
   # Define the default arguments to use with 'lit', and an option for the user
   # to override.