Make `SourceMap` available for early debug-printing of `Span`s #72618

Aaron1011 · 2020-05-26T17:27:23Z

Normally, we debug-print Spans using the SourceMap retrieved from
the global TyCtxt. However, we fall back to printing out the Span's
raw fields (instead of a file and line number) when we try to print a
Span before a TyCtxt is available. This makes debugging early phases
of the compile, such as parsing, much more difficult.

This commit stores a SourceMap in rustc_span::GlOBALS as a fallback.
When a TyCtxt is not available, we try to retrieve one from GLOBALS

only if this is not available do we fall back to the raw field output.

I'm not sure how to write a test for this - however, this can be
verified locally by setting RUSTC_LOG="rustc_parse=debug", and
verifying that the output contains filenames and line numbers.

rust-highfive · 2020-05-26T17:27:27Z

r? @ecstatic-morse

(rust_highfive has picked a reviewer for you, use r? to override)

petrochenkov · 2020-05-27T19:34:24Z

cc #72669

…crum rustc_session: Cleanup session creation Noticed while reviewing rust-lang#72618.

petrochenkov · 2020-05-30T18:32:09Z

This is a bit hacky, but we don't have much choice here, I guess.
I'll approve this once #72669 lands.

…crum rustc_session: Cleanup session creation Noticed while reviewing rust-lang#72618.

bors · 2020-05-31T01:22:21Z

☔ The latest upstream changes (presumably #72794) made this pull request unmergeable. Please resolve the merge conflicts.

Aaron1011 · 2020-05-31T04:25:57Z

@petrochenkov: Rebased

src/librustc_interface/interface.rs

petrochenkov · 2020-05-31T09:33:47Z

r=me after the cleanup (#72618 (comment)) and squashing commits.

petrochenkov · 2020-05-31T10:27:17Z

Actually I need to look at #72799 first.
UPD: Done.

Aaron1011 · 2020-05-31T19:59:32Z

@bors r=petrochenkov

bors · 2020-05-31T19:59:33Z

📌 Commit 5909611eb1e9c1ac0207ec631dee8f51217fe1d8 has been approved by petrochenkov

Normally, we debug-print `Spans` using the `SourceMap` retrieved from the global `TyCtxt`. However, we fall back to printing out the `Span`'s raw fields (instead of a file and line number) when we try to print a `Span` before a `TyCtxt` is available. This makes debugging early phases of the compile, such as parsing, much more difficult. This commit stores a `SourceMap` in `rustc_span::GlOBALS` as a fallback. When a `TyCtxt` is not available, we try to retrieve one from `GLOBALS` - only if this is not available do we fall back to the raw field output. I'm not sure how to write a test for this - however, this can be verified locally by setting `RUSTC_LOG="rustc_parse=debug"`, and verifying that the output contains filenames and line numbers.

Aaron1011 · 2020-05-31T21:31:25Z

Forgot to run tidy

@bors r- r=petrochenkov

bors · 2020-05-31T21:31:27Z

📌 Commit 717fd66 has been approved by petrochenkov

…r=petrochenkov Make `SourceMap` available for early debug-printing of `Span`s Normally, we debug-print `Spans` using the `SourceMap` retrieved from the global `TyCtxt`. However, we fall back to printing out the `Span`'s raw fields (instead of a file and line number) when we try to print a `Span` before a `TyCtxt` is available. This makes debugging early phases of the compile, such as parsing, much more difficult. This commit stores a `SourceMap` in `rustc_span::GlOBALS` as a fallback. When a `TyCtxt` is not available, we try to retrieve one from `GLOBALS` - only if this is not available do we fall back to the raw field output. I'm not sure how to write a test for this - however, this can be verified locally by setting `RUSTC_LOG="rustc_parse=debug"`, and verifying that the output contains filenames and line numbers.

bors · 2020-06-02T14:47:19Z

⌛ Testing commit 717fd66 with merge b6d3f6ea8c95f4d6d9d16f428c79df5e0342db1a...

Dylan-DPC-zz · 2020-06-02T16:30:39Z

@bors retry yield

bors · 2020-06-03T00:10:55Z

⌛ Testing commit 717fd66 with merge c0c40d8ccada6a3ecbbbd09e4e88b7082588dbb8...

Dylan-DPC-zz · 2020-06-03T01:00:31Z

@bors retry

bors · 2020-06-04T04:38:57Z

⌛ Testing commit 717fd66 with merge 6279571...

bors · 2020-06-04T08:32:28Z

☀️ Test successful - checks-azure
Approved by: petrochenkov
Pushing 6279571 to master...

Currently, the `Debug` impl for `proc_macro::Span` just prints out the byte range. This can make debugging proc macros (either as a crate author or as a compiler developer) very frustrating, since neither the actual filename nor the `SyntaxContext` is displayed. This commit adds a perma-unstable flag `-Z span-debug`. When enabled, the `Debug` impl for `proc_macro::Span` simply forwards directly to `rustc_span::Span`. Once rust-lang#72618 is merged, this will start displaying actual line numbers. While `Debug` impls are not subject to Rust's normal stability guarnatees, we probably shouldn't expose any additional information on stable until `#![feature(proc_macro_span)]` is stabilized. Otherwise, we would be providing a 'backdoor' way to access information that's supposed be behind unstable APIs.

…rochenkov Add `-Z span-debug` to allow for easier debugging of proc macros Currently, the `Debug` impl for `proc_macro::Span` just prints out the byte range. This can make debugging proc macros (either as a crate author or as a compiler developer) very frustrating, since neither the actual filename nor the `SyntaxContext` is displayed. This commit adds a perma-unstable flag `-Z span-debug`. When enabled, the `Debug` impl for `proc_macro::Span` simply forwards directly to `rustc_span::Span`. Once rust-lang#72618 is merged, this will start displaying actual line numbers. While `Debug` impls are not subject to Rust's normal stability guarnatees, we probably shouldn't expose any additional information on stable until `#![feature(proc_macro_span)]` is stabilized. Otherwise, we would be providing a 'backdoor' way to access information that's supposed be behind unstable APIs.

rust-highfive assigned ecstatic-morse May 26, 2020

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label May 26, 2020

petrochenkov self-assigned this May 26, 2020

petrochenkov mentioned this pull request May 27, 2020

rustc_session: Cleanup session creation #72669

Merged

Dylan-DPC-zz pushed a commit to Dylan-DPC-zz/rust that referenced this pull request May 28, 2020

Rollup merge of rust-lang#72669 - petrochenkov:smclean, r=Mark-Simula…

dad479b

…crum rustc_session: Cleanup session creation Noticed while reviewing rust-lang#72618.

RalfJung added a commit to RalfJung/rust that referenced this pull request May 30, 2020

Rollup merge of rust-lang#72669 - petrochenkov:smclean, r=Mark-Simula…

29704a0

…crum rustc_session: Cleanup session creation Noticed while reviewing rust-lang#72618.

petrochenkov added S-blocked Status: Blocked on something else such as an RFC or other implementation work. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels May 30, 2020

ecstatic-morse removed their assignment May 30, 2020

RalfJung added a commit to RalfJung/rust that referenced this pull request May 30, 2020

Rollup merge of rust-lang#72669 - petrochenkov:smclean, r=Mark-Simula…

278e26e

…crum rustc_session: Cleanup session creation Noticed while reviewing rust-lang#72618.

Aaron1011 mentioned this pull request May 30, 2020

Add -Z span-debug to allow for easier debugging of proc macros #72799

Merged

Aaron1011 force-pushed the feature/early-sourcemap branch from a1149ff to d13b3f0 Compare May 31, 2020 04:25

Aaron1011 added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-blocked Status: Blocked on something else such as an RFC or other implementation work. labels May 31, 2020

petrochenkov reviewed May 31, 2020

View reviewed changes

src/librustc_interface/interface.rs Outdated Show resolved Hide resolved

petrochenkov 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-review Status: Awaiting review from the assignee but also interested parties. labels May 31, 2020

Aaron1011 force-pushed the feature/early-sourcemap branch 2 times, most recently from f836cf2 to 5909611 Compare May 31, 2020 19:59

bors removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label May 31, 2020

bors added the S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. label May 31, 2020

Aaron1011 force-pushed the feature/early-sourcemap branch from 5909611 to 717fd66 Compare May 31, 2020 21:31

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 May 31, 2020

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 May 31, 2020

RalfJung mentioned this pull request Jun 1, 2020

Rollup of 6 pull requests #72877

Closed

bors added the merged-by-bors This PR was explicitly merged by bors. label Jun 4, 2020

bors merged commit 6279571 into rust-lang:master Jun 4, 2020

jyn514 mentioned this pull request Feb 16, 2021

ICE instead of syntax error while calling super() #82156

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Make `SourceMap` available for early debug-printing of `Span`s #72618

Make `SourceMap` available for early debug-printing of `Span`s #72618

Aaron1011 commented May 26, 2020

rust-highfive commented May 26, 2020

petrochenkov commented May 27, 2020

petrochenkov commented May 30, 2020

bors commented May 31, 2020

Aaron1011 commented May 31, 2020

petrochenkov commented May 31, 2020

petrochenkov commented May 31, 2020 •

edited

Loading

Aaron1011 commented May 31, 2020

bors commented May 31, 2020

Aaron1011 commented May 31, 2020

bors commented May 31, 2020

bors commented Jun 2, 2020

Dylan-DPC-zz commented Jun 2, 2020

bors commented Jun 3, 2020

Dylan-DPC-zz commented Jun 3, 2020

bors commented Jun 4, 2020

bors commented Jun 4, 2020

Make SourceMap available for early debug-printing of Spans #72618

Make SourceMap available for early debug-printing of Spans #72618

Conversation

Aaron1011 commented May 26, 2020

rust-highfive commented May 26, 2020

petrochenkov commented May 27, 2020

petrochenkov commented May 30, 2020

bors commented May 31, 2020

Aaron1011 commented May 31, 2020

petrochenkov commented May 31, 2020

petrochenkov commented May 31, 2020 • edited Loading

Aaron1011 commented May 31, 2020

bors commented May 31, 2020

Aaron1011 commented May 31, 2020

bors commented May 31, 2020

bors commented Jun 2, 2020

Dylan-DPC-zz commented Jun 2, 2020

bors commented Jun 3, 2020

Dylan-DPC-zz commented Jun 3, 2020

bors commented Jun 4, 2020

bors commented Jun 4, 2020

Make `SourceMap` available for early debug-printing of `Span`s #72618

Make `SourceMap` available for early debug-printing of `Span`s #72618

petrochenkov commented May 31, 2020 •

edited

Loading