Add new `-Z dump-mir-spanview` option #76074

richkadel · 2020-08-29T18:18:30Z

Similar to -Z dump-mir-graphviz, this adds the option to write
HTML+CSS files that allow users to analyze the spans associated with MIR
elements (by individual statement, just terminator, or overall basic
block).

This PR was split out from PR #76004, and exposes an API for spanview
HTML+CSS files that is also used to analyze code regions chosen for
coverage instrumentation (in a follow-on PR).

Rust compiler MCP rust-lang/compiler-team#278

Relevant issue: #34701 - Implement support for LLVMs code coverage
instrumentation

r? @tmandry
FYI @wesleywiser

bors · 2020-08-30T18:07:58Z

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

tmandry

Mind leaving a note about this flag on this page of the rustc dev guide? (sources here)

I also liked the gif you made on #76004, is that still what this looks like?

compiler/rustc_mir/src/util/spanview.rs

compiler/rustc_session/src/config.rs

compiler/rustc_session/src/options.rs

tmandry · 2020-09-01T01:14:17Z

I checked this out and ran it locally. Some observations:

It's really useful to view alongside the MIR to see how each basic block maps back to the source!
I can't see the tooltip I saw in your screen capture, did you take that out?
Toggling between the expanded and unexpanded view on mouseover is a bit annoying since you might want to leave it expanded while scrolling the source. A click toggle might be nicer.
Some of the lines can get quite long when expanded and go off the edge; it might be nice to have an option that wraps lines, if it's easy to do. (I was viewing it in an HTML preview in vscode, so only had the width I'd have in a normal text editor.)

It might also be useful to have the "reverse" view one day (see the MIR with the original source in a tooltip). Of course, this view makes perfect sense for source code coverage.

tmandry · 2020-09-01T01:17:09Z

Also, can you rebase and remove the merge commits? We try to keep merge commits out of PRs generally.

richkadel · 2020-09-01T01:30:28Z

I can't see the tooltip I saw in your screen capture, did you take that out?

No, I definitely included the tooltip. It shows up for me. I don't think I have any special extension for viewing the HTML preview. One way I bring it up from the HTML file is I right-click it's tab in VSCode, and click the first menu option, "Open Preview".

The tooltip just works.

You can also try opening the file inside your Chrome browser.

As for the other comments, those are all good suggestions, but I tried things like this and they either involved adding more complexity that seemed unnecessary (for a first release), or required JavaScript (which I'm not against, but it adds more compatibility risk).

There are other things I'd like to improve as well, but none of them are show stoppers IMO.

Can you log these as a feature request?

richkadel · 2020-09-01T01:32:05Z

Also, can you rebase and remove the merge commits? We try to keep merge commits out of PRs generally.

Ugh, yeah. I didn't noticed those leaked in when I had to rebase yesterday morning. Will fix.

richkadel · 2020-09-01T01:47:49Z

Also, can you rebase and remove the merge commits? We try to keep merge commits out of PRs generally.

Ugh, yeah. I didn't noticed those leaked in when I had to rebase yesterday morning. Will fix.

done

tmandry · 2020-09-01T02:01:05Z

@bors r+

bors · 2020-09-01T02:01:06Z

📌 Commit 5acd7eb25cda0efef746b7ca4a3a9f0b99a3c490 has been approved by tmandry

Similar to `-Z dump-mir-graphviz`, this adds the option to write HTML+CSS files that allow users to analyze the spans associated with MIR elements (by individual statement, just terminator, or overall basic block). This PR was split out from PR rust-lang#76004, and exposes an API for spanview HTML+CSS files that is also used to analyze code regions chosen for coverage instrumentation (in a follow-on PR). Rust compiler MCP rust-lang/compiler-team#278 Relevant issue: rust-lang#34701 - Implement support for LLVMs code coverage instrumentation

richkadel · 2020-09-01T06:09:16Z

@tmandry @wesleywiser - I had to rebase after the dependency landed.

It might require re-submitting to bors.

wesleywiser · 2020-09-01T13:13:14Z

@bors r+ rollup

bors · 2020-09-01T13:13:15Z

📌 Commit 6b5869a has been approved by wesleywiser

@ghost

Rollup of 14 pull requests Successful merges: - rust-lang#74880 (Add trailing comma support to matches macro) - rust-lang#76074 (Add new `-Z dump-mir-spanview` option) - rust-lang#76088 (Add more examples to lexicographic cmp on Iterators.) - rust-lang#76099 (Add info about `!` and `impl Trait`) - rust-lang#76126 (Use "Fira Sans" for crate list font) - rust-lang#76132 (Factor out StmtKind::MacCall fields into `MacCallStmt` struct) - rust-lang#76143 (Give a better error message for duplicate built-in macros) - rust-lang#76158 (Stabilise link-self-contained option) - rust-lang#76201 (Move to intra-doc links for library/core/src/panic.rs) - rust-lang#76206 (Make all methods of `std::net::Ipv6Addr` const) - rust-lang#76207 (# Move to intra-doc links for library/core/src/clone.rs) - rust-lang#76212 (Document lint missing_doc_code_examples is nightly-only) - rust-lang#76218 (lexer: Tiny improvement to shebang detection) - rust-lang#76221 (Clean up header in `iter` docs for `for` loops) Failed merges: r? @ghost

@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

…em,Nilstrieb Remove `-Zdump-mir-spanview` The `-Zdump-mir-spanview` flag was added back in rust-lang#76074, as a development/debugging aid for the initial work on what would eventually become `-Cinstrument-coverage`. It causes the compiler to emit an HTML file containing a function's source code, with various spans highlighted based on the contents of MIR. When the suggestion was made to [triage and remove unnecessary `-Z` flags (Zulip)](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.60-Z.60.20option.20triage), I noted that this flag could potentially be worth removing, but I wanted to keep it around to see whether I found it useful for my own coverage work. But when I actually tried to use it, I ran into various issues (e.g. it crashes on `tests/coverage/closure.rs`). If I can't trust it to work properly without a full overhaul, then instead of diving down a rabbit hole of trying to fix arcane span-handling bugs, it seems better to just remove this obscure old code entirely. --- `@rustbot` label +A-code-coverage

…em,Nilstrieb Remove `-Zdump-mir-spanview` The `-Zdump-mir-spanview` flag was added back in rust-lang#76074, as a development/debugging aid for the initial work on what would eventually become `-Cinstrument-coverage`. It causes the compiler to emit an HTML file containing a function's source code, with various spans highlighted based on the contents of MIR. When the suggestion was made to [triage and remove unnecessary `-Z` flags (Zulip)](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.60-Z.60.20option.20triage), I noted that this flag could potentially be worth removing, but I wanted to keep it around to see whether I found it useful for my own coverage work. But when I actually tried to use it, I ran into various issues (e.g. it crashes on `tests/coverage/closure.rs`). If I can't trust it to work properly without a full overhaul, then instead of diving down a rabbit hole of trying to fix arcane span-handling bugs, it seems better to just remove this obscure old code entirely. --- ``@rustbot`` label +A-code-coverage

…em,Nilstrieb Remove `-Zdump-mir-spanview` The `-Zdump-mir-spanview` flag was added back in rust-lang#76074, as a development/debugging aid for the initial work on what would eventually become `-Cinstrument-coverage`. It causes the compiler to emit an HTML file containing a function's source code, with various spans highlighted based on the contents of MIR. When the suggestion was made to [triage and remove unnecessary `-Z` flags (Zulip)](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.60-Z.60.20option.20triage), I noted that this flag could potentially be worth removing, but I wanted to keep it around to see whether I found it useful for my own coverage work. But when I actually tried to use it, I ran into various issues (e.g. it crashes on `tests/coverage/closure.rs`). If I can't trust it to work properly without a full overhaul, then instead of diving down a rabbit hole of trying to fix arcane span-handling bugs, it seems better to just remove this obscure old code entirely. --- ```@rustbot``` label +A-code-coverage

…em,Nilstrieb Remove `-Zdump-mir-spanview` The `-Zdump-mir-spanview` flag was added back in rust-lang#76074, as a development/debugging aid for the initial work on what would eventually become `-Cinstrument-coverage`. It causes the compiler to emit an HTML file containing a function's source code, with various spans highlighted based on the contents of MIR. When the suggestion was made to [triage and remove unnecessary `-Z` flags (Zulip)](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.60-Z.60.20option.20triage), I noted that this flag could potentially be worth removing, but I wanted to keep it around to see whether I found it useful for my own coverage work. But when I actually tried to use it, I ran into various issues (e.g. it crashes on `tests/coverage/closure.rs`). If I can't trust it to work properly without a full overhaul, then instead of diving down a rabbit hole of trying to fix arcane span-handling bugs, it seems better to just remove this obscure old code entirely. --- ````@rustbot```` label +A-code-coverage

Rollup merge of rust-lang#119566 - Zalathar:remove-spanview, r=Swatinem,Nilstrieb Remove `-Zdump-mir-spanview` The `-Zdump-mir-spanview` flag was added back in rust-lang#76074, as a development/debugging aid for the initial work on what would eventually become `-Cinstrument-coverage`. It causes the compiler to emit an HTML file containing a function's source code, with various spans highlighted based on the contents of MIR. When the suggestion was made to [triage and remove unnecessary `-Z` flags (Zulip)](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.60-Z.60.20option.20triage), I noted that this flag could potentially be worth removing, but I wanted to keep it around to see whether I found it useful for my own coverage work. But when I actually tried to use it, I ran into various issues (e.g. it crashes on `tests/coverage/closure.rs`). If I can't trust it to work properly without a full overhaul, then instead of diving down a rabbit hole of trying to fix arcane span-handling bugs, it seems better to just remove this obscure old code entirely. --- ````@rustbot```` label +A-code-coverage

rust-highfive assigned tmandry Aug 29, 2020

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 29, 2020

richkadel mentioned this pull request Aug 29, 2020

Tools, tests, and experimenting with MIR-derived coverage counters #76004

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richkadel force-pushed the llvm-coverage-map-gen-6b.5.1 branch from 55f7ece to b993ccf Compare August 30, 2020 21:51

richkadel mentioned this pull request Aug 30, 2020

Adds two source span utility functions used in source-based coverage #76003

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tmandry approved these changes Sep 1, 2020

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richkadel force-pushed the llvm-coverage-map-gen-6b.5.1 branch from b993ccf to 5acd7eb Compare September 1, 2020 01:43

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 Sep 1, 2020

richkadel force-pushed the llvm-coverage-map-gen-6b.5.1 branch from 2b0c469 to 6b5869a Compare September 1, 2020 06:06

richkadel mentioned this pull request Sep 1, 2020

Adds documentation to cover spanview output rust-lang/rustc-dev-guide#844

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tmandry mentioned this pull request Sep 2, 2020

Rollup of 14 pull requests #76231

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bors merged commit 5f28831 into rust-lang:master Sep 2, 2020

cuviper added this to the 1.48.0 milestone Nov 17, 2023

Zalathar mentioned this pull request Jan 4, 2024

Remove -Zdump-mir-spanview #119566

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Add new `-Z dump-mir-spanview` option #76074

Add new `-Z dump-mir-spanview` option #76074

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Add new -Z dump-mir-spanview option #76074

Add new -Z dump-mir-spanview option #76074

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Add new `-Z dump-mir-spanview` option #76074

Add new `-Z dump-mir-spanview` option #76074