mirror of
https://github.com/rust-lang/rust.git
synced 2025-11-01 13:34:38 +00:00
1692ebd5b5
coverage: Avoid splitting spans during span extraction/refinement This PR removes or simplifies some of the steps involved in extracting coverage-relevant spans from MIR, and preparing them for use in coverage instrumentation metadata. A common theme is that we now try harder to avoid modifying or combining spans in non-trivial ways, because those modifications present the most risk for weird behaviour or ICEs. The main changes are: - When extracting spans from MIR call terminators, try to restrict them to just the function name. - Instead of splitting spans around “holes”, just discard any span that overlaps with a hole. - Instead of splitting macro-invocation spans into two parts, truncate them to just the macro name and subsequent `!`. --- This results in a lot of tiny changes to the spans that end up in coverage metadata, and a few changes to coverage reports. Judging by test snapshots, these changes appear to be quite minor in practice.