[CMake] Adjust the variables set by LLVMConfig.cmake

[john.brawn]

Summary

When using LLVMConfig.cmake from an installed toolchain in order to build a loadable pass using add_llvm_loadable_module LLVM_ENABLE_PLUGINS and LLVM_PLUGIN_EXT must be set. Also make LLVM_DEFINITIONS be set to what it actually is.

[chapuni]

It'd be good if we were going toward that our scripts would work without LLVMHandleOptions.cmake.

Are there any discussions about it?

[john.brawn]

In D13214#255239, @chapuni wrote:

It'd be good if we were going toward that our scripts would work without LLVMHandleOptions.cmake.

Are there any discussions about it?

I'm not sure what you mean by this? Building a loadable pass already doesn't require using HandleLLVMOptions.cmake. The only partial dependency there is that HandleLLVMOptions.cmake sets -std=c++11 in the CXXFLAGS and if you don't use HandleLLVMOptions.cmake then you have to do that manually, but that's it as far as I can tell.

[chapuni]

Okay, it'd be good direction.

llvm/trunk/cmake/modules/LLVMConfig.cmake.in

 set(LLVM_ENABLE_THREADS @LLVM_ENABLE_THREADS@)
 
 set(LLVM_ENABLE_ZLIB @LLVM_ENABLE_ZLIB@)
 
 set(LLVM_NATIVE_ARCH @LLVM_NATIVE_ARCH@)
 
 set(LLVM_ENABLE_PIC @LLVM_ENABLE_PIC@)
 
+set(LLVM_ENABLE_PLUGINS @LLVM_ENABLE_PLUGINS@)
+set(LLVM_PLUGIN_EXT @LLVM_PLUGIN_EXT@)
+
 set(LLVM_ON_UNIX @LLVM_ON_UNIX@)
 set(LLVM_ON_WIN32 @LLVM_ON_WIN32@)
 
 set(LLVM_LIBDIR_SUFFIX @LLVM_LIBDIR_SUFFIX@)
 
 set(LLVM_INCLUDE_DIRS "@LLVM_CONFIG_INCLUDE_DIRS@")
 set(LLVM_LIBRARY_DIRS "@LLVM_CONFIG_LIBRARY_DIRS@")
-set(LLVM_DEFINITIONS "-D__STDC_LIMIT_MACROS" "-D__STDC_CONSTANT_MACROS")
+set(LLVM_DEFINITIONS "@LLVM_DEFINITIONS@")
 set(LLVM_CMAKE_DIR "@LLVM_CONFIG_CMAKE_DIR@")
 set(LLVM_TOOLS_BINARY_DIR "@LLVM_CONFIG_TOOLS_BINARY_DIR@")
 
 if(NOT TARGET LLVMSupport)
   include("@LLVM_CONFIG_EXPORTS_FILE@")
 endif()
 
 include(${LLVM_CMAKE_DIR}/LLVM-Config.cmake)