What logs are kept when bulding clang?

Beginners
1

I’m trying to build clang to have Asan available for aarch64-linux-gnu cross compile target. I am getting complaints about scudo_standalone dependency not found that I think are red herrings because the preceding configure fails on every feature test it tries.

Are there build logs left behind other than what appears on stdout/stderr of the build? I’m not finding any but thought I’d ask.

Am using llvm-project 16.0.5 from github. Building on Ubuntu 20.04.

2

There should be more detailed CMake logs under CMakeFiles/CMakeOutput.log and CMakeFiles/CMakeError.log. The latter is particularly useful for figuring out why configure tests are failing; you just have to be careful about distinguishing expected configure test failures (e.g. testing for Windows-specific things when you’re targeting Linux) vs. unexpected ones.

If you’re using the runtimes build (LLVM_ENABLE_RUNTIMES), you’ll want to look at the CMakeFiles directory under the runtimes build directory instead of main LLVM build directory. It’s probably easiest to just do find . -name CMakeError.log under your build directory to find the relevant one.

3

This is exactly what I needed. I was able to determine that the runtimes config failed because my cross-compile environment isn’t right. Specifically, ld didn’t recognize the aarch64linux emulation mode.

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