Auto merge of #4551 - mikerite:fix-ice-reporting, r=llogiq

[rust.git] / clippy_lints / src / mut_mut.rs

diff --git a/clippy_lints/src/mut_mut.rs b/clippy_lints/src/mut_mut.rs
index fc3107c3068d8cee621786a4be06734591e428e2..decc684b66778bc5b1e022f1f2efc89fb5073afa 100644 (file)
--- a/clippy_lints/src/mut_mut.rs
+++ b/clippy_lints/src/mut_mut.rs
@@ -1,55 +1,50 @@
+use crate::utils::{higher, span_lint};
 use rustc::hir;
 use rustc::hir::intravisit;
-use rustc::lint::*;
+use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
 use rustc::ty;
-use utils::{higher, in_external_macro, span_lint};
+use rustc::{declare_lint_pass, declare_tool_lint};
 
-/// **What it does:** Checks for instances of `mut mut` references.
-///
-/// **Why is this bad?** Multiple `mut`s don't add anything meaningful to the
-/// source. This is either a copy'n'paste error, or it shows a fundamental
-/// misunderstanding of references.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// let x = &mut &mut y;
-/// ```
-declare_lint! {
+declare_clippy_lint! {
+    /// **What it does:** Checks for instances of `mut mut` references.
+    ///
+    /// **Why is this bad?** Multiple `mut`s don't add anything meaningful to the
+    /// source. This is either a copy'n'paste error, or it shows a fundamental
+    /// misunderstanding of references.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// ```rust
+    /// # let mut y = 1;
+    /// let x = &mut &mut y;
+    /// ```
     pub MUT_MUT,
-    Allow,
-    "usage of double-mut refs, e.g. `&mut &mut ...`"
+    pedantic,
+    "usage of double-mut refs, e.g., `&mut &mut ...`"
 }
 
-#[derive(Copy,Clone)]
-pub struct MutMut;
-
-impl LintPass for MutMut {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(MUT_MUT)
-    }
-}
+declare_lint_pass!(MutMut => [MUT_MUT]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MutMut {
     fn check_block(&mut self, cx: &LateContext<'a, 'tcx>, block: &'tcx hir::Block) {
-        intravisit::walk_block(&mut MutVisitor { cx: cx }, block);
+        intravisit::walk_block(&mut MutVisitor { cx }, block);
     }
 
     fn check_ty(&mut self, cx: &LateContext<'a, 'tcx>, ty: &'tcx hir::Ty) {
         use rustc::hir::intravisit::Visitor;
 
-        MutVisitor { cx: cx }.visit_ty(ty);
+        MutVisitor { cx }.visit_ty(ty);
     }
 }
 
-pub struct MutVisitor<'a, 'tcx: 'a> {
+pub struct MutVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
 }
 
 impl<'a, 'tcx> intravisit::Visitor<'tcx> for MutVisitor<'a, 'tcx> {
     fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
-        if in_external_macro(self.cx, expr.span) {
+        if in_external_macro(self.cx.sess(), expr.span) {
             return;
         }
 
@@ -62,30 +57,48 @@ fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
             // Let's ignore the generated code.
             intravisit::walk_expr(self, arg);
             intravisit::walk_expr(self, body);
-        } else if let hir::ExprAddrOf(hir::MutMutable, ref e) = expr.node {
-            if let hir::ExprAddrOf(hir::MutMutable, _) = e.node {
-                span_lint(self.cx,
-                          MUT_MUT,
-                          expr.span,
-                          "generally you want to avoid `&mut &mut _` if possible");
-            } else if let ty::TyRef(_, ty::TypeAndMut { mutbl: hir::MutMutable, .. }) = self.cx.tables.expr_ty(e).sty {
-                span_lint(self.cx,
-                          MUT_MUT,
-                          expr.span,
-                          "this expression mutably borrows a mutable reference. Consider reborrowing");
+        } else if let hir::ExprKind::AddrOf(hir::MutMutable, ref e) = expr.node {
+            if let hir::ExprKind::AddrOf(hir::MutMutable, _) = e.node {
+                span_lint(
+                    self.cx,
+                    MUT_MUT,
+                    expr.span,
+                    "generally you want to avoid `&mut &mut _` if possible",
+                );
+            } else if let ty::Ref(_, _, hir::MutMutable) = self.cx.tables.expr_ty(e).sty {
+                span_lint(
+                    self.cx,
+                    MUT_MUT,
+                    expr.span,
+                    "this expression mutably borrows a mutable reference. Consider reborrowing",
+                );
             }
         }
     }
 
     fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
-        if let hir::TyRptr(_, hir::MutTy { ty: ref pty, mutbl: hir::MutMutable }) = ty.node {
-            if let hir::TyRptr(_, hir::MutTy { mutbl: hir::MutMutable, .. }) = pty.node {
-                span_lint(self.cx,
-                          MUT_MUT,
-                          ty.span,
-                          "generally you want to avoid `&mut &mut _` if possible");
+        if let hir::TyKind::Rptr(
+            _,
+            hir::MutTy {
+                ty: ref pty,
+                mutbl: hir::MutMutable,
+            },
+        ) = ty.node
+        {
+            if let hir::TyKind::Rptr(
+                _,
+                hir::MutTy {
+                    mutbl: hir::MutMutable, ..
+                },
+            ) = pty.node
+            {
+                span_lint(
+                    self.cx,
+                    MUT_MUT,
+                    ty.span,
+                    "generally you want to avoid `&mut &mut _` if possible",
+                );
             }
-
         }
 
         intravisit::walk_ty(self, ty);