Suggest appropriate syntax on missing lifetime specifier in return type #55173

estebank · 2018-10-18T04:08:42Z

Suggest using 'static when a lifetime is missing in the return type
with a structured suggestion instead of a note.

rust-highfive · 2018-10-18T04:08:52Z

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

oli-obk · 2018-10-18T07:33:28Z

src/librustc/middle/resolve_lifetime.rs

-            help!(db, "consider giving it a 'static lifetime");
+            let msg = "consider giving it a 'static lifetime";
+            match self.tcx.sess.source_map().span_to_snippet(span) {
+                Ok(ref snippet) if snippet == "&" => db.span_suggestion_with_applicability(


This match has some formattings that threw me off. I think it would be easier on the eyes to have something along the lines of

Ok(ref snippet) => { let (sugg, app) = match &snippet[..] { "&" => ("&'static ".to_owned(), Applicability::MachineApplicable), "'_" => ("'static ".to_owned(), Applicability::MachineApplicable), snippet => (format!("{} + 'static", snippet), Applicability::MaybeIncorrect), }; db.span_suggestion_with_applicability(span, msg, sugg, app); }

oli-obk · 2018-10-18T07:34:13Z

src/librustc/middle/resolve_lifetime.rs

-                 lifetime"
-            );
+            let msg = "consider giving it an explicit bounded or 'static lifetime";
+            match self.tcx.sess.source_map().span_to_snippet(span) {


same here, in fact, this could probably be unified into a function

oli-obk · 2018-10-18T07:35:02Z

src/test/ui/associated-types/bound-lifetime-in-binding-only.elision.stderr

-   |                       ^ expected lifetime parameter
+   |                       ^
+   |                       |
+   |                       expected lifetime parameter


maybe remove the "expected lifetime parameter" message completely? It already says "missing lifetime specifier" in the error message

estebank · 2018-10-18T22:18:48Z

@oli-obk addressed review comments

oli-obk · 2018-10-19T06:31:50Z

src/librustc/middle/resolve_lifetime.rs

+    fn suggest_lifetime(&self, db: &mut DiagnosticBuilder<'_>, span: Span, msg: &str) -> bool {
+        match self.tcx.sess.source_map().span_to_snippet(span) {
+            Ok(ref snippet) => {
+                let (sugg, applicability) = if &snippet[..] == "&" {


Suggested change

let (sugg, applicability) = if &snippet[..] == "&" {

let (sugg, applicability) = if snippet == "&" {

src/test/ui/lifetimes/lifetime-elision-return-type-trait.rs

oli-obk · 2018-10-19T06:34:43Z

r=me with nits applied

estebank · 2018-10-19T18:16:59Z

@bors r=oli-obk

bors · 2018-10-19T18:17:01Z

📌 Commit 3c096ec2f46542adf968139ce8709c8e690b6b1b has been approved by oli-obk

Suggest using `'static` when a lifetime is missing in the return type with a structured suggestion instead of a note.

Co-Authored-By: estebank <[email protected]>

estebank · 2018-10-22T23:54:26Z

@bors r=oli-obk rollup

bors · 2018-10-22T23:54:26Z

📌 Commit dd91c8f has been approved by oli-obk

Suggest appropriate syntax on missing lifetime specifier in return type Suggest using `'static` when a lifetime is missing in the return type with a structured suggestion instead of a note. Fix rust-lang#55170.

@ghost

Rollup of 22 pull requests Successful merges: - #53507 (Add doc for impl From for Waker) - #53931 (Gradually expanding libstd's keyword documentation) - #54965 (update tcp stream documentation) - #54977 (Accept `Option<Box<$t:ty>>` in macro argument) - #55138 (in which unused-parens suggestions heed what the user actually wrote) - #55173 (Suggest appropriate syntax on missing lifetime specifier in return type) - #55200 (Documents `From` implementations for `Stdio`) - #55245 (submodules: update clippy from 5afdf8b to b1d0343) - #55247 (Clarified code example in char primitive doc) - #55251 (Fix a typo in the documentation of RangeInclusive) - #55253 (only issue "variant of the expected type" suggestion for enums) - #55254 (Correct trailing ellipsis in name_from_pat) - #55269 (fix typos in various places) - #55282 (Remove redundant clone) - #55285 (Do some copy editing on the release notes) - #55291 (Update stdsimd submodule) - #55296 (Set RUST_BACKTRACE=0 for rustdoc-ui/failed-doctest-output.rs) - #55306 (Regression test for #54478.) - #55328 (Fix doc for new copysign functions) - #55340 (Operands no longer appear in places) - #55345 (Remove is_null) - #55348 (Update RELEASES.md after destabilization of non_modrs_mods) Failed merges: r? @ghost

rust-highfive assigned oli-obk Oct 18, 2018

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Oct 18, 2018

estebank force-pushed the suggest-static branch from 7f7ca81 to e2a83e4 Compare October 18, 2018 05:33

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estebank force-pushed the suggest-static branch from 8cd303b to abd3856 Compare October 18, 2018 20:27

oli-obk reviewed Oct 19, 2018

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src/test/ui/lifetimes/lifetime-elision-return-type-trait.rs Show resolved Hide resolved

estebank force-pushed the suggest-static branch from cb07fa1 to 3c096ec Compare October 19, 2018 18:16

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 Oct 19, 2018

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estebank and others added 3 commits October 22, 2018 14:54

Suggest appropriate syntax on missing lifetime specifier in return type

e1e52eb

Suggest using `'static` when a lifetime is missing in the return type with a structured suggestion instead of a note.

review comments

d0bd69a

[review comments] modify test and clean up code

dd91c8f

Co-Authored-By: estebank <[email protected]>

estebank force-pushed the suggest-static branch from 3c096ec to dd91c8f Compare October 22, 2018 21:56

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 Oct 22, 2018

pietroalbini mentioned this pull request Oct 23, 2018

Rollup of 19 pull requests #55295

Closed

kennytm mentioned this pull request Oct 24, 2018

Rollup of 28 pull requests #55320

Closed

pietroalbini mentioned this pull request Oct 25, 2018

Rollup of 22 pull requests #55347

Merged

bors merged commit dd91c8f into rust-lang:master Oct 25, 2018

estebank mentioned this pull request Nov 7, 2018

Bad diagnostic for bad lifetime syntax #36179

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estebank deleted the suggest-static branch November 9, 2023 05:22

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Suggest appropriate syntax on missing lifetime specifier in return type #55173

Suggest appropriate syntax on missing lifetime specifier in return type #55173

estebank commented Oct 18, 2018

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bors commented Oct 22, 2018

	let (sugg, applicability) = if &snippet[..] == "&" {
	let (sugg, applicability) = if snippet == "&" {

Suggest appropriate syntax on missing lifetime specifier in return type #55173

Suggest appropriate syntax on missing lifetime specifier in return type #55173

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