bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #77765 - amshafer:master, r=petrochenkov

Browse source 
Add LLVM flags to limit DWARF version to 2 on BSD

This has been a thorn in my side for a while, I can finally generate flamegraphs of rust programs on bsd again. This fixes dtrace profiling on freebsd, I think it might help with lldb as well but I can't test that because my current rust-lldb setup is messed up.

I'm limiting the dwarf version to 2 on all bsd's (netbsd/openbsd/freebsd) since it looks like this applies to all of them, but I have only tested on freebsd.

Let me know if there's anything I can improve!

---
Currently on FreeBSD dtrace profiling does not work and shows jumbled/incorrect
symbols in the backtraces. FreeBSD does not support the latest versions of DWARF
in dtrace (and lldb?) yet, and needs to be limited to DWARF2 in the same way as macos.

This adds an is_like_bsd flag since it was missing. NetBSD/OpenBSD/FreeBSD all
match this.

This effectively copies #11864 but targets FreeBSD instead of macos.
This commit is contained in:
Dylan DPC 2020-10-14 02:30:34 +02:00 • committed by GitHub
commit 596235281c
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
8 changed files with 23 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

6
compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
View file

@ -120,10 +120,8 @@ pub fn finalize(cx: &CodegenCx<'_, '_>) {
// for macOS to understand. For more info see #11352
// This can be overridden using --llvm-opts -dwarf-version,N.
// Android has the same issue (#22398)
if cx.sess().target.target.options.is_like_osx
|| cx.sess().target.target.options.is_like_android
{
llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), 2)
if let Some(version) = cx.sess().target.target.options.dwarf_version {
llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), version)
}
// Indicate that we want CodeView debug information on MSVC