[llvm-dev] Building A Project Against LLVM (original) (raw)

Rarrum via llvm-dev llvm-dev at lists.llvm.org
Thu May 14 23:05:37 PDT 2020

I decided to start playing around with building my own programming language recently, and to use LLVM to handle the assembly-level details. I'm on Kubuntu 18.04, and I started out using LLVM 6.0 from Kubuntu's packages. I put together code for dealing with my language, then went over the Kaleidoscope tutorials (which have been extremely helpful btw!). I was able to successfully get my own compiler to generate IR using LLVM, use PassManager to write that to a native .o file, use gcc to link that, and execute a tiny program written in my own language.

I also decided it was a good time to learn CMake, so I set up my project using that. The CMakeLists.txt file I'm using is essentially just taken from: https://llvm.org/docs/CMake.html#embedding-llvm-in-your-project - though originally it would not link. From scouring the internet I made 2 changes to get that working: replaced "support core irreader" with "all", and replaced "${llvm_libs}" with just "LLVM".

However as I was starting to play with setting up JIT, I hit more differences between the version of LLVM in Kubuntu and the version the examples and documentation were written against. So I decided to try to update to a newer version of LLVM.. and this is where I've been stuck for several days now. Here are the steps I've taken:

At this point I'm not sure what to try next. Is there additional documentation somewhere for how to "install" a current release of LLVM correctly?

For reference here's my final CMakeLists.txt file:

cmake_minimum_required(VERSION 3.10)

project(CBreakCompiler)

set(CMAKE_CXX_STANDARD 17) set(CMAKE_CXX_STANDARD_REQUIRED True) add_compile_options(-Wall)

find_package(LLVM 10.0.0 REQUIRED CONFIG)

message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}") message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")

include_directories(${LLVM_INCLUDE_DIRS}) add_definitions(${LLVM_DEFINITIONS})

add_executable(CBreakCompiler src/main.cpp src/Parser.cpp src/SourceTokenizer.cpp src/IRCompiler.cpp src/CompiledOutput.cpp)

llvm_map_components_to_libnames(llvm_libs all) target_link_libraries(CBreakCompiler ${llvm_libs})

And a snippet from the cmake output corresponding to those message lines:

-- Found LLVM 10.0.0 -- Using LLVMConfig.cmake in: /usr/local/lib/cmake/llvm

There are dozens of link errors.. the first few and last few are:

CMakeFiles/CBreakCompiler.dir/src/main.cpp.o:(.data.rel+0x0): undefined reference to llvm::DisableABIBreakingChecks' CMakeFiles/CBreakCompiler.dir/src/main.cpp.o: In function std::default_deletellvm::LLVMContext::operator()(llvm::LLVMContext*) const': main.cpp:(.text.ZNKSt14default_deleteIN4llvm11LLVMContextEEclEPS1[ZNKSt14default_deleteIN4llvm11LLVMContextEEclEPS1]+0x1e): undefined reference to llvm::LLVMContext::~LLVMContext()' ... CMakeFiles/CBreakCompiler.dir/src/CompiledOutput.cpp.o:(.data.rel.ro+0xe0): undefined reference to llvm::raw_ostream::anchor()' CMakeFiles/CBreakCompiler.dir/src/CompiledOutput.cpp.o:(.data.rel.ro+0xf8): undefined reference to typeinfo for llvm::raw_pwrite_stream' CMakeFiles/CBreakCompiler.dir/src/CompiledOutput.cpp.o:(.data.rel.ro+0x110): undefined reference to typeinfo for llvm::raw_ostream' -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200514/c777693f/attachment.html>

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