c6bd873403
With the new behaviour, the /MD or similar options aren't added to e.g. CMAKE_CXX_FLAGS_RELEASE, but are added separately by CMake. They can be changed by the cmake variable CMAKE_MSVC_RUNTIME_LIBRARY or with the target property MSVC_RUNTIME_LIBRARY. LLVM has had its own custom CMake flags, e.g. LLVM_USE_CRT_RELEASE, which affects which CRT is used for release mode builds. Deprecate these and direct users to use CMAKE_MSVC_RUNTIME_LIBRARY directly instead (and do a best effort attempt at setting CMAKE_MSVC_RUNTIME_LIBRARY based on the existing LLVM_USE_CRT_ flags). This only handles the simple cases, it doesn't handle multi-config generators with different LLVM_USE_CRT_* variables for different configs though, but that's probably fine - we should move over to the new upstream CMake mechanism anyway, and push users towards that. Change code in compiler-rt, that previously tried to override the CRT choice to /MT, to set CMAKE_MSVC_RUNTIME_LIBRARY instead of meddling in the old variables. This resolves the policy issue in https://github.com/llvm/llvm-project/issues/63286, and should handle the issues that were observed originally when the minimum CMake version was bumped, in https://github.com/llvm/llvm-project/issues/62719 and https://github.com/llvm/llvm-project/issues/62739. Differential Revision: https://reviews.llvm.org/D155233
The LLVM Compiler Infrastructure
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called "LLVM". This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Getting the Source Code and Building LLVM
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Getting in touch
Join the LLVM Discourse forums, Discord chat, or #llvm IRC channel on OFTC.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.