rustc_pass_by_value: handle inferred generic types (with _)

matthiaskrgr · Jan 11, 2022 · 2728af7 · 2728af7
1 parent 959bf2b
commit 2728af7
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Showing 3 changed files with 25 additions and 15 deletions.
diff --git a/compiler/rustc_lint/src/pass_by_value.rs b/compiler/rustc_lint/src/pass_by_value.rs
@@ -73,19 +73,15 @@ fn gen_args(cx: &LateContext<'_>, segment: &PathSegment<'_>) -> String {
  let params = args
  .args
  .iter()
- .filter_map(|arg| match arg {
- GenericArg::Lifetime(lt) => Some(lt.name.ident().to_string()),
+ .map(|arg| match arg {
+ GenericArg::Lifetime(lt) => lt.name.ident().to_string(),
  GenericArg::Type(ty) => {
- let snippet =
- cx.tcx.sess.source_map().span_to_snippet(ty.span).unwrap_or_default();
- Some(snippet)
+ cx.tcx.sess.source_map().span_to_snippet(ty.span).unwrap_or_default()
  }
  GenericArg::Const(c) => {
- let snippet =
- cx.tcx.sess.source_map().span_to_snippet(c.span).unwrap_or_default();
- Some(snippet)
+ cx.tcx.sess.source_map().span_to_snippet(c.span).unwrap_or_default()
  }
- _ => None,
+ GenericArg::Infer(_) => String::from("_"),
  })
  .collect::<Vec<_>>();
 

diff --git a/src/test/ui-fulldeps/internal-lints/rustc_pass_by_value.rs b/src/test/ui-fulldeps/internal-lints/rustc_pass_by_value.rs
@@ -105,11 +105,13 @@ struct WithParameters<T, const N: usize, M = u32> {
 }
 
 impl<T> WithParameters<T, 1> {
- fn test(
+ fn test<'a>(
  value: WithParameters<T, 1>,
- reference: &WithParameters<T, 1>, //~ ERROR passing `WithParameters<T, 1>` by reference
+ reference: &'a WithParameters<T, 1>, //~ ERROR passing `WithParameters<T, 1>` by reference
  reference_with_m: &WithParameters<T, 1, u32>, //~ ERROR passing `WithParameters<T, 1, u32>` by reference
- ) {
+ ) -> &'a WithParameters<T, 1> {
+ //~^ ERROR passing `WithParameters<T, 1>` by reference
+ reference as &WithParameters<_, 1> //~ ERROR passing `WithParameters<_, 1>` by reference
  }
 }
 

diff --git a/src/test/ui-fulldeps/internal-lints/rustc_pass_by_value.stderr b/src/test/ui-fulldeps/internal-lints/rustc_pass_by_value.stderr
@@ -103,14 +103,26 @@ LL | reference: &CustomAlias,
 error: passing `WithParameters<T, 1>` by reference
  --> $DIR/rustc_pass_by_value.rs:110:20
  |
-LL | reference: &WithParameters<T, 1>,
- | ^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1>`
+LL | reference: &'a WithParameters<T, 1>,
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1>`
 
 error: passing `WithParameters<T, 1, u32>` by reference
  --> $DIR/rustc_pass_by_value.rs:111:27
  |
 LL | reference_with_m: &WithParameters<T, 1, u32>,
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1, u32>`
 
-error: aborting due to 18 previous errors
+error: passing `WithParameters<T, 1>` by reference
+ --> $DIR/rustc_pass_by_value.rs:112:10
+ |
+LL | ) -> &'a WithParameters<T, 1> {
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1>`
+
+error: passing `WithParameters<_, 1>` by reference
+ --> $DIR/rustc_pass_by_value.rs:114:22
+ |
+LL | reference as &WithParameters<_, 1>
+ | ^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<_, 1>`
+
+error: aborting due to 20 previous errors