rust-lang / rust-lang/rustc-perf

Add a page to show the diff in symbols

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C-feature-request
Dominant language
Rust
Stars
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Forks
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Avg merge
10h 52m
Merged PRs (30d)
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Description

To track down regressions due to LLVM's optimizations changing due to subtle code changes can be hard. One useful tool in that box is dumping the symbols in librustc_driver.so and comparing them at different commits. I think it could be helpful to add a page that shows this diff for each perf run

My current command for dumping the symbols is

nm build/x86_64-unknown-linux-gnu/stage1/lib/librustc_driver-a150cfa449c4561a.so | grep -oP '^[^ ]* . \K.*$' | c++filt

What do you think about this? Is it out of scope for the perf pages? Should I rather create a small command that downloads these binaries from try builds and compares them locally?

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Research direction

Start with the existing perf pages and the supplied symbol-dumping command using nm and c++filt. Clarify whether the work should compare symbols in binaries from each perf run or become a local download tool; done should be a defined, reproducible symbol diff for the selected runs.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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