bors[bot] dbb1c1b4b1 Merge #11184 ... 11184: Correctly pass through mutable parameter references when extracting a function r=Veykril a=Vannevelj Fixes https://github.com/rust-analyzer/rust-analyzer/issues/10277 I have based this investigation based on my understanding of [the Borrowing chapter](https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html) but I wasn't able to debug the test runs or see it in action in an IDE. I'll try to figure out how to do that for future PRs but for now, the tests seem to confirm my understanding. I'll lay out my hypothesis below. Here we define the parameters for the to-be-generated function: 7409880a07/crates/ide_assists/src/handlers/extract_function.rs (L882) Three values in particular are important here: `requires_mut`, `is_copy` and `move_local`. These will in turn be used here to determine the kind of parameter: 7409880a07/crates/ide_assists/src/handlers/extract_function.rs (L374-L381) and then here to determine what transformation is needed for the calling argument: 7409880a07/crates/ide_assists/src/handlers/extract_function.rs (L383-L390) which then gets transformed here: 7409880a07/crates/syntax/src/ast/make.rs (L381-L383) What I believe is happening is that * `requires_mut` is `false` (it already is marked as mutable), * `is_copy` is `false` (`Foo` does not implement `Copy`), and * `move_local` is `false` (it has further usages) According to the pattern matching in `fn kind()`, that would lead to `ParamKind::SharedRef` which in turn applies a transformation that prepends `&`. However if I look at the chapter on borrowing then we only need to mark an argument as a reference if we actually own it. In this case the value is passed through as a reference parameter into the current function which means we never had ownership in the first place. By including the additional check for a reference parameter, `move_local` now becomes `true` and the resulting parameter is now `ParamKind::Value` which will avoid applying any transformations. This was further obscured by the fact that you need further usages of the variable or `move_local` would be considered `true` after all. I didn't follow it in depth but it appears this idea applies for both the generated argument and the generated parameter. There are existing tests that account for `&mut` values but they refer to local variables for which we do have ownership and as such they didn't expose this issue. Co-authored-by: Jeroen Vannevel <jer_vannevel@outlook.com>		2022-01-04 10:19:37 +00:00
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base_db	Merge #11069	2021-12-20 16:50:35 +00:00
cfg	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
flycheck	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
hir	Fix tool module classification not working correctly	2022-01-02 23:14:18 +01:00
hir_def	minor: add missing test	2022-01-03 17:21:43 +03:00
hir_expand	minor: drop dead code	2022-01-02 19:03:38 +03:00
hir_ty	Merge #11115	2022-01-03 16:00:05 +00:00
ide	Merge #11177	2022-01-03 02:03:03 +00:00
ide_assists	reduced the tests to their bare essence	2022-01-04 10:11:04 +00:00
ide_completion	minor: Simplify	2022-01-04 10:56:28 +01:00
ide_db	minor: Cleanup syntax highlighting	2022-01-02 22:23:05 +01:00
ide_diagnostics	Merge #11028	2021-12-20 13:45:35 +00:00
ide_ssr	compress	2021-12-28 19:17:34 +03:00
limit	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
mbe	simplify	2022-01-03 16:27:16 +03:00
parser	add empty input tests	2022-01-02 18:50:32 +03:00
paths	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
proc_macro_api	Merge #11028	2021-12-20 13:45:35 +00:00
proc_macro_srv	Merge #11028	2021-12-20 13:45:35 +00:00
proc_macro_test	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
profile	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
project_model	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
rust-analyzer	internal: Handle macro calls better in highlighting	2022-01-02 19:10:10 +01:00
sourcegen	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
stdx	minor: replace panics with types	2022-01-02 19:05:37 +03:00
syntax	Migrate to SyntaxNodePtr in new rowan	2021-12-29 23:48:53 -08:00
test_utils	fix: Do not complete Drop::drop, complete std::mem::drop instead	2021-12-22 02:25:38 +01:00
text_edit	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
toolchain	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
tt	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
vfs	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00
vfs-notify	Bump MSRV (1.57)	2021-12-16 01:56:12 +05:00