Can't figure out how to get CMake to pull in the correct headers for a custom clang driver

Question

CMake is giving me a real hard time, here. I checked out llvm, clang, and extras, and I created a custom driver folder, added it to the llvm\tools\clang\tools\extra\CMakeLists.txt and created my own CMakeLists.txt:

cmake_minimum_required(VERSION 3.8)
set(LLVM_LINK_COMPONENTS
  Support
  )

set(CMAKE_CXX_FLAGS ${LLVM_CONFIG})
set(CMAKE_CXX_COMPILER "clang++")  

add_clang_executable(mydriver
  main.cpp
  )

set(CLANG_LIBS clangFrontend clangDriver clangSerialization clangParse
    clangCodeGen  clangSema clangAnalysis clangEdit clangAST clangLex
    clangBasic )

target_link_libraries(mydriver ${CLANG_LIBS})
target_link_libraries(mydriver ${LLVM_LIBS})

CMake works fine. I target VS2017 and build the mydriver project with msbuild

λ msbuild tools\clang\tools\extra\mydriver\mydriver.vcxproj

This results in the following error:

"C:\dev\llvm-build\tools\clang\tools\extra\mydriver\mydriver.vcxproj" (default target) (1) ->
(ClCompile target) ->
  C:\dev\llvm\tools\clang\tools\extra\mydriver\main.cpp(45): error C2027: use of undefined type 'clang::Preprocessor Options' [C:\dev\llvm-build\tools\clang\tools\extra\mydriver\mydriver.vcxproj]
  C:\dev\llvm\tools\clang\tools\extra\mydriver\main.cpp(45): error C2228: left of '.addRemappedFile' must have class /struct/union [C:\dev\llvm-build\tools\clang\tools\extra\mydriver\mydriver.vcxproj]
  C:\dev\llvm\tools\clang\tools\extra\mydriver\main.cpp(50): error C2664: 'void clang::CompilerInstance::setInvocati on(std::shared_ptr<clang::CompilerInvocation>)': cannot convert argument 1 from 'clang::CompilerInvocation *' to 'st d::shared_ptr<clang::CompilerInvocation>' [C:\dev\llvm-build\tools\clang\tools\extra\mydriver\mydriver.vcxproj]

However, clangLex is clearly included in the CLANG_LIBS variable in my CMakeLists.txt. The documentation of the clang::PreprocessorOptions class seems to indicate that I have the right libs included.

Any ideas?

Please note that this question is closely related to this one: Generate assembly from C code in memory using libclang

score 1 · Answer 1 · answered May 12 '17 at 00:15

In classic SO fashion, the problem was that the include file had migrated since the example was posted. The clang documentation requires a new header file, that is, in fact, in the include path. All I needed was:

#include <clang/Lex/PreprocessorOptions.h>

Sorry folks, nothing to see here.

Can't figure out how to get CMake to pull in the correct headers for a custom clang driver

1 Answers1