needless_borrow: print the type in the lint message

changelog: needless_borrow: print type in lint message
rust-lang · Dec 13, 2020 · 144ee13 · 144ee13
1 parent b7db5bf
commit 144ee13
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Showing 5 changed files with 34 additions and 6 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -27,6 +27,12 @@ path = "src/main.rs"
 name = "clippy-driver"
 path = "src/driver.rs"
 
+[target.'cfg(NOT_A_PLATFORM)'.dependencies]
+rustc_driver = { path = "/home/matthias/vcs/github/rust/compiler/rustc_driver" }
+rustc_errors = { path = "/home/matthias/vcs/github/rust/compiler/rustc_errors" }
+rustc_interface = { path = "/home/matthias/vcs/github/rust/compiler/rustc_interface" }
+rustc_middle = { path = "/home/matthias/vcs/github/rust/compiler/rustc_middle" }
+
 [dependencies]
 # begin automatic update
 clippy_lints = { version = "0.0.212", path = "clippy_lints" }

diff --git a/clippy_lints/Cargo.toml b/clippy_lints/Cargo.toml
@@ -16,6 +16,28 @@ license = "MIT OR Apache-2.0"
 keywords = ["clippy", "lint", "plugin"]
 edition = "2018"
 
+[target.'cfg(NOT_A_PLATFORM)'.dependencies]
+rustc_ast = { path = "/home/matthias/vcs/github/rust/compiler/rustc_ast" }
+rustc_ast_pretty = { path = "/home/matthias/vcs/github/rust/compiler/rustc_ast_pretty" }
+rustc_attr = { path = "/home/matthias/vcs/github/rust/compiler/rustc_attr" }
+rustc_data_structures = { path = "/home/matthias/vcs/github/rust/compiler/rustc_data_structures" }
+rustc_errors = { path = "/home/matthias/vcs/github/rust/compiler/rustc_errors" }
+rustc_hir = { path = "/home/matthias/vcs/github/rust/compiler/rustc_hir" }
+rustc_hir_pretty = { path = "/home/matthias/vcs/github/rust/compiler/rustc_hir_pretty" }
+rustc_index = { path = "/home/matthias/vcs/github/rust/compiler/rustc_index" }
+rustc_infer = { path = "/home/matthias/vcs/github/rust/compiler/rustc_infer" }
+rustc_lexer = { path = "/home/matthias/vcs/github/rust/compiler/rustc_lexer" }
+rustc_lint = { path = "/home/matthias/vcs/github/rust/compiler/rustc_lint" }
+rustc_middle = { path = "/home/matthias/vcs/github/rust/compiler/rustc_middle" }
+rustc_mir = { path = "/home/matthias/vcs/github/rust/compiler/rustc_mir" }
+rustc_parse = { path = "/home/matthias/vcs/github/rust/compiler/rustc_parse" }
+rustc_parse_format = { path = "/home/matthias/vcs/github/rust/compiler/rustc_parse_format" }
+rustc_session = { path = "/home/matthias/vcs/github/rust/compiler/rustc_session" }
+rustc_span = { path = "/home/matthias/vcs/github/rust/compiler/rustc_span" }
+rustc_target = { path = "/home/matthias/vcs/github/rust/compiler/rustc_target" }
+rustc_trait_selection = { path = "/home/matthias/vcs/github/rust/compiler/rustc_trait_selection" }
+rustc_typeck = { path = "/home/matthias/vcs/github/rust/compiler/rustc_typeck" }
+
 [dependencies]
 cargo_metadata = "0.12"
 if_chain = "1.0.0"

diff --git a/clippy_lints/src/needless_borrow.rs b/clippy_lints/src/needless_borrow.rs
@@ -47,7 +47,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrow {
             return;
         }
         if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, ref inner) = e.kind {
-            if let ty::Ref(..) = cx.typeck_results().expr_ty(inner).kind() {
+            if let ty::Ref(_,ty,_) = cx.typeck_results().expr_ty(inner).kind() {
                 for adj3 in cx.typeck_results().expr_adjustments(e).windows(3) {
                     if let [Adjustment {
                         kind: Adjust::Deref(_), ..
@@ -62,8 +62,8 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrow {
                             cx,
                             NEEDLESS_BORROW,
                             e.span,
-                            "this expression borrows a reference that is immediately dereferenced \
-                             by the compiler",
+                            &format!("this expression borrows a reference (`&{}`) that is immediately dereferenced \
+                             by the compiler", ty),
                             |diag| {
                                 if let Some(snippet) = snippet_opt(cx, inner.span) {
                                     diag.span_suggestion(

diff --git a/tests/ui/eta.stderr b/tests/ui/eta.stderr
@@ -12,7 +12,7 @@ error: redundant closure found
 LL |     meta(|a| foo(a));
    |          ^^^^^^^^^^ help: remove closure as shown: `foo`
 
-error: this expression borrows a reference that is immediately dereferenced by the compiler
+error: this expression borrows a reference (`&u8`) that is immediately dereferenced by the compiler
   --> $DIR/eta.rs:24:21
    |
 LL |     all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted

diff --git a/tests/ui/needless_borrow.stderr b/tests/ui/needless_borrow.stderr
@@ -1,4 +1,4 @@
-error: this expression borrows a reference that is immediately dereferenced by the compiler
+error: this expression borrows a reference (`&i32`) that is immediately dereferenced by the compiler
   --> $DIR/needless_borrow.rs:14:15
    |
 LL |     let c = x(&&a);
@@ -12,7 +12,7 @@ error: this pattern creates a reference to a reference
 LL |     if let Some(ref cake) = Some(&5) {}
    |                 ^^^^^^^^ help: change this to: `cake`
 
-error: this expression borrows a reference that is immediately dereferenced by the compiler
+error: this expression borrows a reference (`&i32`) that is immediately dereferenced by the compiler
   --> $DIR/needless_borrow.rs:28:15
    |
 LL |         46 => &&a,