[DO NOT MERGE] Consistent handling of semicolons in macro expansions by Aaron1011 · Pull Request #78685 · rust-lang/rust

Aaron1011 · 2020-11-02T21:34:52Z

Implements 'Proposal 2' from #61733 (comment)

This PR treats semicolon-less macro invocations like statements. This allows the following code to compile:

fnmain(){macro_rules! a {($e:expr) => { $e;}}a!(true)}

To avoid making macro behavior more inconsistent, macros expanded in expression position no longer ignore trailing semicolons in the expansion. This broke several things in the standard library - in fact, we can't even get rustfmt to pass until rust-lang/rustfmt#4507 is merged

Given all of the issues this has expoesd with the standard library (and many test cases), I expect this to cause a significant amount of ecosystem breakage. I'm opening this for a Crater run - we'll almost certainly need to do a gradual rollout if this is accepted. Fortunately, it's easy to convert the macro_rules! error into a warning.

rust-highfive · 2020-11-02T21:34:56Z

r? @varkor

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

rust-highfive · 2020-11-02T21:34:57Z

⚠️Warning⚠️

These commits modify submodules.

Aaron1011 · 2020-11-02T21:35:01Z

@bors try

Aaron1011 · 2020-11-02T21:35:08Z

r? @ghost

bors · 2020-11-02T21:35:14Z

⌛ Trying commit 6522b7a82e35fe64fa731578724e8e861c5dbd84 with merge 1a1b32118e83a86f430f0c6665d870751ca08118...

Aaron1011 · 2020-11-02T22:11:49Z

@bors try

bors · 2020-11-02T22:11:59Z

⌛ Trying commit 2f6d12cf5b3469a4b1cd57098ae1366f3fe47f16 with merge ea2a67936e3f9b71d6067d67723b66bac8d387b4...

Aaron1011 · 2020-11-02T22:45:01Z

@bors try

bors · 2020-11-02T22:45:11Z

⌛ Trying commit 003157547b12ef2b81db5aaa223070614b3a4327 with merge bc19ff65d7d862e3bca14037b3c0cb818328cfcc...

ghost · 2020-11-02T22:57:35Z

Suggested change
returnErr(Utf8Error{valid_up_to: old_offset,error_len: $error_len })
Err(Utf8Error{valid_up_to: old_offset,error_len: $error_len })
Is return required here?

Yes - for example, https://github.com/Aaron1011/rust/blob/003157547b12ef2b81db5aaa223070614b3a4327/library/core/src/str/validations.rs#L136-L138 uses this to bail out early.

Aaron1011 · 2020-11-02T23:38:19Z

The build doesn't even complete because of anyhow:

https://github.com/dtolnay/anyhow/blob/c25be95f1a24f7497d2b4530ffcb4f90d3871975/src/macros.rs#L54-L64

Opened dtolnay/anyhow#120. The fact that three different crates (libstd, stdarch, and anyhow) have all been broken by this change doesn't seem to bode well for the Crater results.

cc rust-lang#33953 Currently, the following code produces an error ```rust fn main() { macro_rules! a { ($e:expr) => { $e; } } a!(true) } ```

Aaron1011 · 2020-11-10T23:03:08Z

@bors try

bors · 2020-11-10T23:03:20Z

⌛ Trying commit 677d6cb with merge 1cd838451943835da5228ec71c7bae5b8268efdd...

rust-log-analyzer · 2020-11-10T23:35:43Z

The job dist-x86_64-linux of your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

##[debug]Evaluating job defaults
Prepare all required actions
Getting action download info
Download action repository 'actions/checkout@v2'
##[debug]Download 'https://api.github.com/repos/actions/checkout/tarball/5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f' to '/home/runner/work/_actions/_temp_f1546009-49e5-4d74-88f0-3707a744473a/a70b31de-6dfe-49c9-897c-8e9f09119fac.tar.gz'
##[debug]Unwrap 'actions-checkout-5a4ac90' to '/home/runner/work/_actions/actions/checkout/v2'
##[debug]Archive '/home/runner/work/_actions/_temp_f1546009-49e5-4d74-88f0-3707a744473a/a70b31de-6dfe-49c9-897c-8e9f09119fac.tar.gz' has been unzipped into '/home/runner/work/_actions/actions/checkout/v2'.
Download action repository 'rust-lang/simpleinfra@master'
##[debug]Download 'https://api.github.com/repos/rust-lang/simpleinfra/tarball/caeabfd7dcd0342420d12a285e4a50b0a3ae2cc8' to '/home/runner/work/_actions/_temp_b2a0a2fb-e406-4c30-b766-9e7f68e73516/e702b4f1-4660-49cf-be72-20c2a78e698c.tar.gz'
##[debug]Unwrap 'rust-lang-simpleinfra-caeabfd' to '/home/runner/work/_actions/rust-lang/simpleinfra/master'
##[debug]Archive '/home/runner/work/_actions/_temp_b2a0a2fb-e406-4c30-b766-9e7f68e73516/e702b4f1-4660-49cf-be72-20c2a78e698c.tar.gz' has been unzipped into '/home/runner/work/_actions/rust-lang/simpleinfra/master'.
##[debug]action.yml for action: '/home/runner/work/_actions/rust-lang/simpleinfra/master/github-actions/cancel-outdated-builds/action.yml'.
##[debug]Set step 'run1' display name to: 'disable git crlf conversion'
##[debug]Set step 'actionscheckout' display name to: 'checkout the source code'
##[debug]Set step 'run2' display name to: 'configure the PR in which the error message will be posted'
---
::endgroup::
##[endgroup]
::group::Fetching the repository
##[group]Fetching the repository
[command]/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=2 origin +1cd838451943835da5228ec71c7bae5b8268efdd:refs/remotes/origin/try
---
Compiling memchr v2.3.3
Compiling lazy_static v1.4.0
Compiling libc v0.2.79
Compiling serde_derive v1.0.115
Compiling log v0.4.11 (https://github.com/Aaron1011/log?branch=fix/semi#ed7a622a)
Compiling ryu v1.0.5
Compiling regex-syntax v0.6.18
Compiling cfg-if v0.1.10
Compiling cfg-if v1.0.0
---
Compiling serde v1.0.115
Compiling cfg-if v0.1.10
Compiling ppv-lite86 v0.2.8
Compiling siphasher v0.3.3
Compiling log v0.4.11 (https://github.com/Aaron1011/log?branch=fix/semi#ed7a622a)
Compiling cfg-if v1.0.0
Compiling itoa v0.4.6
Compiling mac v0.1.1
Compiling precomputed-hash v0.1.1
---
Compiling syn v1.0.38
Compiling cc v1.0.60
Compiling scopeguard v1.1.0
Compiling smallvec v1.4.2
Compiling log v0.4.11 (https://github.com/Aaron1011/log?branch=fix/semi#ed7a622a)
Compiling instant v0.1.6
Compiling typenum v1.12.0
Compiling version_check v0.9.1
Compiling hashbrown v0.9.0
---
Compiling syn v1.0.38
Compiling cc v1.0.60
Compiling scopeguard v1.1.0
Compiling smallvec v1.4.2
Compiling log v0.4.11 (https://github.com/Aaron1011/log?branch=fix/semi#ed7a622a)
Compiling instant v0.1.6
Compiling typenum v1.12.0
Compiling version_check v0.9.1
Compiling getrandom v0.1.14
---
Documenting stage2 std (x86_64-unknown-linux-gnu)
Uplifting stage1 std (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
Copying stage2 std from stage1 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu)
Documenting core v0.0.0 (/checkout/library/core)
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2065:44
|
2065 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= note: `#[warn(broken_intra_doc_links)]` on by default
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2094:44
|
2094 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2123:44
|
2123 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2152:44
|
2152 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2181:44
|
2181 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2215:44
|
2215 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:5512:44
|
5512 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:5542:44
|
5542 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:5572:44
|
5572 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:5607:44
|
5607 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:5637:44
|
5637 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:5667:44
|
5667 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:19448:44
|
19448 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:19478:44
|
19478 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:19514:44
|
19514 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:19544:44
|
19544 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:19574:44
|
19574 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:19610:44
|
19610 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:21403:44
|
21403 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:21434:44
|
21434 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:21465:44
|
21465 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:21502:44
|
21502 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:21533:44
|
21533 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:21564:44
|
21564 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: unresolved link to `2:0`
warning: unresolved link to `2:0`
--> library/core/src/../../stdarch/crates/core_arch/src/x86/avx512f.rs:2065:44
|
2065 | /// Rounding is done according to the imm8[2:0] parameter, which can be one of:
| ^^^ no item named `2:0` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
warning: 25 warnings emitted
Finished release [optimized + debuginfo] target(s) in 13.26s
Compiling cc v1.0.60
---
Checking smallvec v1.4.2
Compiling unicode-xid v0.2.1
Checking scopeguard v1.1.0
Compiling cc v1.0.60
Compiling log v0.4.11 (https://github.com/Aaron1011/log?branch=fix/semi#ed7a622a)
Checking hashbrown v0.9.0
Checking instant v0.1.6
Compiling typenum v1.12.0
Compiling getrandom v0.1.14

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @rust-lang/infra. (Feature Requests)

bors · 2020-11-10T23:35:53Z

💔 Test failed - checks-actions

petrochenkov · 2020-11-17T18:10:08Z

r? @petrochenkov

bors · 2020-11-18T20:59:08Z

☔ The latest upstream changes (presumably #79167) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

petrochenkov · 2021-02-23T10:20:48Z

Closing due to inactivity.

rust-highfive assigned varkor Nov 2, 2020

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Aaron1011 added 3 commits November 9, 2020 15:13

Parse bang macro as a statement when used in trailing expr position
f650153
cc rust-lang#33953 Currently, the following code produces an error ```rust fn main() { macro_rules! a { ($e:expr) => { $e; } } a!(true) } ```

Work on macro_rules
bb426ba

Fix stdarch
38b670e

Aaron1011 added 4 commits November 9, 2020 15:14

Remove trailing semicolon on a bunch of macros
d1de799

Temporarily allow rustdoc warnings for a try build
b50d1c7

Disable more -Dwarnings
2cdc3a4

Use patched dependencies
677d6cb

Aaron1011 force-pushed the feature/stmt-bang-macro branch from 0031575 to 677d6cbCompare November 10, 2020 23:02

rust-highfive assigned petrochenkov and unassigned varkor Nov 17, 2020

This was referenced Nov 17, 2020
Parse bang macro as a statement when used in trailing expr position #78991
Closed
Properly handle attributes on statements #78296
Merged

Aaron1011 mentioned this pull request Nov 19, 2020
Stop ignoring trailing semicolons in a macro body when a macro is invoked in expression position rust-lang/lang-team#70
Closed

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crlf0710 removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Jan 29, 2021

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petrochenkov closed this Feb 23, 2021

	returnErr(Utf8Error{valid_up_to: old_offset,error_len: $error_len })
	Err(Utf8Error{valid_up_to: old_offset,error_len: $error_len })

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