LLVM_TARGETS_TO_BUILD incomplete documentation (missing "host", "Native")

[PerMildner]

llvm-project/llvm/docs/CMake.rst

Line 832 in a1c0ba1

**LLVM_TARGETS_TO_BUILD**:STRING

1. The "full list" of LLVM_TARGETS_TO_BUILD values is not complete and is missing the useful and commonly used values host and Native.
2. The host and Native values for LLVM_TARGETS_TO_BUILD do not seem to be documented anywhere.

CMake.rst currently says:

LLVM_TARGETS_TO_BUILD:STRING
Semicolon-separated list of targets to build, or all for building all targets. Case-sensitive. Defaults to all. Example: -DLLVM_TARGETS_TO_BUILD="X86;PowerPC". The full list, as of March 2023, is: AArch64;AMDGPU;ARM;AVR;BPF;Hexagon;Lanai;LoongArch;Mips;MSP430;NVPTX;PowerPC;RISCV;Sparc;SystemZ;VE;WebAssembly;X86;XCore

However, many places, both in llvm-project and outside, seem to use the values host and Native, which sounds like useful options. Unfortunately both are undocumented (and it is unclear whether they mean the same thing and why sometimes host is used and sometimes Native).

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor has already been assigned to this issue. If you believe that no one is actually working on it despite an assignment, ping the person. After one week without a response, the assignee may be changed.
2. In the comments of this issue, request for it to be assigned to you, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
6. Run git clang-format HEAD~1 to format your changes.
7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: None (PerMildner)

https://github.com/llvm/llvm-project/blob/a1c0ba1646f5a80dadd34f55e4a36d5409c2675a/llvm/docs/CMake.rst?plain=1#L832

1. The "full list" of LLVM_TARGETS_TO_BUILD values is not complete and is missing the useful and commonly used values host and Native.
2. The host and Native values for LLVM_TARGETS_TO_BUILD do not seem to be documented anywhere.

CMake.rst currently says:

> LLVM_TARGETS_TO_BUILD:STRING
> Semicolon-separated list of targets to build, or all for building all targets. Case-sensitive. Defaults to all. Example: -DLLVM_TARGETS_TO_BUILD="X86;PowerPC". The full list, as of March 2023, is: AArch64;AMDGPU;ARM;AVR;BPF;Hexagon;Lanai;LoongArch;Mips;MSP430;NVPTX;PowerPC;RISCV;Sparc;SystemZ;VE;WebAssembly;X86;XCore

However, many places, both in llvm-project and outside, seem to use the values host and Native, which sounds like useful options. Unfortunately both are undocumented (and it is unclear whether they mean the same thing and why sometimes host is used and sometimes Native).

[harrisonGPU]

@dtcxzyw , Hello, what do you think about this PR:#111382