[libcxxabi] r291506 - [cmake] Obtain LLVM_CMAKE_PATH from llvm-config if available

[Michal Gorny via cfe-commits]

Author: mgorny
Date: Mon Jan  9 17:31:05 2017
New Revision: 291506

URL: http://llvm.org/viewvc/llvm-project?rev=291506&view=rev
Log:
[cmake] Obtain LLVM_CMAKE_PATH from llvm-config if available

Use the new --cmakedir option to obtain LLVM_CMAKE_PATH straight from
llvm-config. Fallback to local reconstruction if llvm-config does not
support this option.

Modified:
    libcxxabi/trunk/CMakeLists.txt

Modified: libcxxabi/trunk/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/CMakeLists.txt?rev=291506&r1=291505&r2=291506&view=diff
==============================================================================
--- libcxxabi/trunk/CMakeLists.txt (original)
+++ libcxxabi/trunk/CMakeLists.txt Mon Jan  9 17:31:05 2017
@@ -49,8 +49,19 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURR
     set(LLVM_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 ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
-    set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm")
     set(LLVM_LIT_PATH "${LLVM_PATH}/utils/lit/lit.py")
+
+    # --cmakedir is supported since llvm r291218 (4.0 release)
+    execute_process(
+      COMMAND ${LLVM_CONFIG_PATH} --cmakedir
+      RESULT_VARIABLE HAD_ERROR
+      OUTPUT_VARIABLE CONFIG_OUTPUT)
+    if(NOT HAD_ERROR)
+      string(STRIP "${CONFIG_OUTPUT}" LLVM_CMAKE_PATH)
+    else()
+      set(LLVM_CMAKE_PATH
+          "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/cmake/llvm")
+    endif()
   else()
     message(FATAL_ERROR "llvm-config not found and LLVM_MAIN_SRC_DIR not defined. "
                         "Reconfigure with -DLLVM_CONFIG_PATH=path/to/llvm-config "