Fix `-Z instrument-coverage` on MSVC by richkadel · Pull Request #76002 · rust-lang/rust

richkadel · 2020-08-27T20:05:47Z

Found that -C link-dead-code (which was enabled automatically
under -Z instrument-coverage) was causing the linking error that
resulted in segmentation faults in coverage instrumented binaries. Link
dead code is now disabled under MSVC, allowing -Z instrument-coverage
to be enabled under MSVC for the first time.

More details are included in Issue #76038 .

Note this PR makes it possible to support Z instrument-coverage but
does not enable instrument coverage for MSVC in existing tests. It will be
enabled in another PR to follow this one (both PRs coming from original
PR #75828).

r? @tmandry
FYI: @wesleywiser

richkadel · 2020-08-28T19:21:20Z

@tmandry @wesleywiser - I've addressed all of Tyler's review comments here, and (as part of that) I created a new, more targeted issue #76038

Thanks!

tmandry · 2020-08-28T20:50:25Z

@richkadel and I discussed enabling the tests for MSVC. It requires some test refactoring that's already done in a follow-up change, so we'll do it in that change.

@bors r+ rollup

bors · 2020-08-28T20:50:26Z

📌 Commit b1c31c353c361290cb99a8c848d3956ca8417424 has been approved by tmandry

bors · 2020-08-30T18:05:32Z

☔ The latest upstream changes (presumably #74862) made this pull request unmergeable. Please resolve the merge conflicts.

tmandry · 2020-08-31T19:01:34Z

@bors r+

bors · 2020-08-31T19:01:35Z

📌 Commit ec9744d7be3c3f025686253b3757781be557f603 has been approved by tmandry

Found that -C link-dead-code (which was enabled automatically under -Z instrument-coverage) was causing the linking error that resulted in segmentation faults in coverage instrumented binaries. Link dead code is now disabled under MSVC, allowing `-Z instrument-coverage` to be enabled under MSVC for the first time. More details are included in Issue rust-lang#76038. (This PR was broken out from PR rust-lang#75828)

tmandry · 2020-09-01T01:52:42Z

@bors r+

bors · 2020-09-01T01:52:43Z

📌 Commit ddb054a has been approved by tmandry

@ghost

Rollup of 12 pull requests Successful merges: - rust-lang#75945 (Use `env::func()`, not 'the function env::func' in docs for std::env) - rust-lang#76002 (Fix `-Z instrument-coverage` on MSVC) - rust-lang#76003 (Adds two source span utility functions used in source-based coverage) - rust-lang#76059 (Clean up E0764) - rust-lang#76103 (Clean up E0769) - rust-lang#76139 (Make `cow_is_borrowed` methods const) - rust-lang#76154 (Fix rustdoc strings indentation) - rust-lang#76161 (Remove notrust in rustc_middle) - rust-lang#76163 (README: Adjust Linux and macOS support platform and architecture) - rust-lang#76166 (Make `StringReader` private) - rust-lang#76172 (Revert rust-lang#75463) - rust-lang#76178 (Update expect-test to 1.0) Failed merges: r? @ghost

Adds a new mir_dump output file in HTML/CSS to visualize code regions and the MIR features that they came from (including overlapping spans). See example below: Includes a basic, MIR-block-based implementation of coverage injection, available via `-Zexperimental-coverage`. This implementation has known flaws and omissions, but is simple enough to validate the new tools and tests. The existing `-Zinstrument-coverage` option currently enables function-level coverage only, which at least appears to generate accurate coverage reports at that level. Experimental coverage is not accurate at this time. When branch coverage works as intended, the `-Zexperimental-coverage` option should be removed. This PR replaces the bulk of PR rust-lang#75828, with the remaining parts of that PR distributed among other separate and indentpent PRs. This PR depends on three of those other PRs: rust-lang#76000, rust-lang#76002, and Rust compiler MCP rust-lang/compiler-team#278 Relevant issue: rust-lang#34701 - Implement support for LLVMs code coverage instrumentation ![Screen-Recording-2020-08-21-at-2](https://user-images.githubusercontent.com/3827298/90972923-ff417880-e4d1-11ea-92bb-8713c6198f6d.gif)

@tmandry

… r=tmandry Tools, tests, and experimenting with MIR-derived coverage counters Leverages the new mir_dump output file in HTML+CSS (from rust-lang#76074) to visualize coverage code regions and the MIR features that they came from (including overlapping spans). See example below. The `run-make-fulldeps/instrument-coverage` test has been refactored to maximize test coverage and reduce code duplication. The new tests support testing with and without `-Clink-dead-code`, so Rust coverage can be tested on MSVC (which, currently, only works with `link-dead-code` _disabled_). New tests validate coverage region generation and coverage reports with multiple counters per function. Starting with a simple `if-else` branch tests, coverage tests for each additional syntax type can be added by simply dropping in a new Rust sample program. Includes a basic, MIR-block-based implementation of coverage injection, available via `-Zexperimental-coverage`. This implementation has known flaws and omissions, but is simple enough to validate the new tools and tests. The existing `-Zinstrument-coverage` option currently enables function-level coverage only, which at least appears to generate accurate coverage reports at that level. Experimental coverage is not accurate at this time. When branch coverage works as intended, the `-Zexperimental-coverage` option should be removed. This PR replaces the bulk of PR rust-lang#75828, with the remaining parts of that PR distributed among other separate and indentpent PRs. This PR depends on two of those other PRs: rust-lang#76002, rust-lang#76003 and rust-lang#76074 Rust compiler MCP rust-lang/compiler-team#278 Relevant issue: rust-lang#34701 - Implement support for LLVMs code coverage instrumentation ![Screen-Recording-2020-08-21-at-2](https://user-images.githubusercontent.com/3827298/90972923-ff417880-e4d1-11ea-92bb-8713c6198f6d.gif) r? @tmandry FYI: @wesleywiser

rust-highfive assigned tmandry Aug 27, 2020

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 27, 2020

richkadel mentioned this pull request Aug 27, 2020
Tools, tests, and experimenting with MIR-derived coverage counters #76004
Merged

tmandry reviewed Aug 28, 2020
View reviewed changes

Comment threadsrc/librustc_session/options.rs Outdated
Comment threadsrc/librustc_session/session.rs Outdated
Comment threadsrc/librustc_session/session.rs Outdated

richkadel mentioned this pull request Aug 28, 2020
rustc -Clink-dead-code causes MSVC linker to produce invalid binaries when LLVM InstrProf counters are enabled #76038
Open

richkadel force-pushed the llvm-coverage-map-gen-6b.3 branch 2 times, most recently from d1086ba to c803eb9Compare August 28, 2020 19:19

richkadel force-pushed the llvm-coverage-map-gen-6b.3 branch from c803eb9 to b1c31c3Compare August 28, 2020 20:15

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 28, 2020

bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Aug 30, 2020

richkadel force-pushed the llvm-coverage-map-gen-6b.3 branch from b1c31c3 to ec9744dCompare August 30, 2020 21:31

richkadel mentioned this pull request Aug 30, 2020
Adds two source span utility functions used in source-based coverage #76003
Merged

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Aug 31, 2020

richkadel force-pushed the llvm-coverage-map-gen-6b.3 branch from ec9744d to ddb054aCompare September 1, 2020 01:41

tmandry mentioned this pull request Sep 1, 2020
Rollup of 12 pull requests #76186
Merged

bors merged commit 6d834a4 into rust-lang:masterSep 1, 2020

cuviper added this to the 1.48.0 milestone Nov 17, 2023

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Fix `-Z instrument-coverage` on MSVC - #76002

Fix `-Z instrument-coverage` on MSVC#76002
bors merged 1 commit into
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