Handle changing of LLVM_ENABLE_FFI.

If someone first configure build with LLVM_ENABLE_FFI=1 and then turn it
off, the build will fail in lib/ExecutionEngine/Interpreter because
Interpreter will try still to #include <ffi/ffi.h>, but there are no
include_directories(${FFI_INCLUDE_DIR}) now.

This patch unset()'s HAVE_FFI_H and HAVE_FFI_FFI_H from cache file if
LLVM_ENABLE_FFI=0. This forces CMake to update config.h.

Patch by arrowdodger!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128769 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index c5ec54eb0c6e3e724a4db181b02f2e39205dd83f..e446853ef75a8650307fe8470f3200a5791d5910 100755 (executable)
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -271,6 +271,10 @@ if( LLVM_ENABLE_FFI )
   check_symbol_exists(ffi_call ${FFI_HEADER} HAVE_FFI_CALL)
   list(REMOVE_ITEM CMAKE_REQUIRED_INCLUDES ${FFI_INCLUDE_PATH})
   list(REMOVE_ITEM CMAKE_REQUIRED_LIBRARIES ${FFI_LIBRARY_PATH})
+else()
+  unset(HAVE_FFI_FFI_H CACHE)
+  unset(HAVE_FFI_H CACHE)
+  unset(HAVE_FFI_CALL CACHE)
 endif( LLVM_ENABLE_FFI )
 
 # Define LLVM_MULTITHREADED if gcc atomic builtins exists.