Build llvm, without arm

[hughperkins]

No description provided.

[johnnynunez]

@hughperkins close this

[hughperkins]

I need it to build 17.

One option I was thinking is to parametrize the main build, to be able to choose to not build arm.

But until I do that, I need this particular builder.

[johnnynunez]

I need it to build 17.

One option I was thinking is to parametrize the main build, to be able to choose to not build arm.

But until I do that, I need this particular builder.

you can add the things that we fixed, maybe now builds for arm

[hughperkins]

There's a build of 17.0.6 here: https://github.com/Genesis-Embodied-AI/gstaichi-sdk-builds/actions/runs/18036925400 It is failing for ARM.

[johnnynunez]

There's a build of 17.0.6 here: https://github.com/Genesis-Embodied-AI/gstaichi-sdk-builds/actions/runs/18036925400 It is failing for ARM.

it is ok! Not change the script. It is a bug: llvm/llvm-project#78691

Why the build fails

GCC 14 on ARM introduces new predefined macros for SME/ACLE attributes, such as __arm_streaming, which expand into C++11 attributes like [[arm::streaming]].

LLVM 17’s Clang headers generate keyword tokens using macros like kw_##X.

When X is a macro (e.g. _arm_streaming) that expands into [[...]], the preprocessor tries to paste kw with [. That produces an invalid token and triggers errors like:

error: pasting "kw_" and "[" does not give a valid preprocessing token

Why only LLVM 17 is affected

LLVM 15/16: too old to run into these new GCC 14 ARM attributes.

LLVM 18 and newer: already include the upstream fix that prevents premature macro expansion (they use the EMPTY ## X trick).

LLVM 17.x: the fix was never backported, so builds break specifically there with GCC 14 on ARM.