]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/ptr.rs
BinOpKind
[rust.git] / clippy_lints / src / ptr.rs
index 8f42750e19b12935b8e50467f84a3b3eecb27417..2ecdf983e6bdafd76ad6f91d7a4bdd1bc9d00e69 100644 (file)
@@ -3,14 +3,14 @@
 use std::borrow::Cow;
 use rustc::hir::*;
 use rustc::hir::map::NodeItem;
+use rustc::hir::QPath;
 use rustc::lint::*;
 use rustc::ty;
 use syntax::ast::NodeId;
 use syntax::codemap::Span;
 use syntax_pos::MultiSpan;
-use utils::{match_qpath, match_type, paths, snippet_opt, span_lint, span_lint_and_then,
-            walk_ptrs_hir_ty};
-use utils::ptr::get_spans;
+use crate::utils::{match_qpath, match_type, paths, snippet_opt, span_lint, span_lint_and_then, walk_ptrs_hir_ty};
+use crate::utils::ptr::get_spans;
 
 /// **What it does:** This lint checks for function arguments of type `&String`
 /// or `&Vec` unless the references are mutable. It will also suggest you
@@ -42,9 +42,9 @@
 /// ```rust
 /// fn foo(&Vec<u32>) { .. }
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub PTR_ARG,
-    Warn,
+    style,
     "fn arguments of the type `&Vec<...>` or `&String`, suggesting to use `&[...]` or `&str` \
      instead, respectively"
 }
@@ -61,9 +61,9 @@
 /// ```rust
 /// if x == ptr::null { .. }
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub CMP_NULL,
-    Warn,
+    style,
     "comparing a pointer to a null pointer, suggesting to use `.is_null()` instead."
 }
 
@@ -86,9 +86,9 @@
 /// ```rust
 /// fn foo(&Foo) -> &mut Bar { .. }
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub MUT_FROM_REF,
-    Warn,
+    correctness,
     "fns that create mutable refs from immutable ref args"
 }
 
@@ -103,7 +103,7 @@ fn get_lints(&self) -> LintArray {
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for PointerPass {
     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
-        if let ItemFn(ref decl, _, _, _, _, body_id) = item.node {
+        if let ItemFn(ref decl, _, _, body_id) = item.node {
             check_fn(cx, decl, item.id, Some(body_id));
         }
     }
@@ -121,14 +121,18 @@ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx ImplItem)
 
     fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem) {
         if let TraitItemKind::Method(ref sig, ref trait_method) = item.node {
-            let body_id = if let TraitMethod::Provided(b) = *trait_method { Some(b) } else { None };
+            let body_id = if let TraitMethod::Provided(b) = *trait_method {
+                Some(b)
+            } else {
+                None
+            };
             check_fn(cx, &sig.decl, item.id, body_id);
         }
     }
 
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
-        if let ExprBinary(ref op, ref l, ref r) = expr.node {
-            if (op.node == BiEq || op.node == BiNe) && (is_null_path(l) || is_null_path(r)) {
+        if let ExprKind::Binary(ref op, ref l, ref r) = expr.node {
+            if (op.node == BinOpKind::Eq || op.node == BinOpKind::Ne) && (is_null_path(l) || is_null_path(r)) {
                 span_lint(
                     cx,
                     CMP_NULL,
@@ -148,21 +152,25 @@ fn check_fn(cx: &LateContext, decl: &FnDecl, fn_id: NodeId, opt_body_id: Option<
     for (idx, (arg, ty)) in decl.inputs.iter().zip(fn_ty.inputs()).enumerate() {
         if let ty::TyRef(
             _,
-            ty::TypeAndMut {
-                ty,
-                mutbl: MutImmutable,
-            },
+            ty,
+            MutImmutable
         ) = ty.sty
         {
             if match_type(cx, ty, &paths::VEC) {
                 let mut ty_snippet = None;
-                if_let_chain!([
-                    let TyPath(QPath::Resolved(_, ref path)) = walk_ptrs_hir_ty(arg).node,
-                    let Some(&PathSegment{parameters: Some(ref parameters), ..}) = path.segments.last(),
-                    parameters.types.len() == 1,
-                ], {
-                    ty_snippet = snippet_opt(cx, parameters.types[0].span);
-                });
+                if_chain! {
+                    if let TyPath(QPath::Resolved(_, ref path)) = walk_ptrs_hir_ty(arg).node;
+                    if let Some(&PathSegment{args: Some(ref parameters), ..}) = path.segments.last();
+                    then {
+                        let types: Vec<_> = parameters.args.iter().filter_map(|arg| match arg {
+                            GenericArg::Type(ty) => Some(ty),
+                            _ => None,
+                        }).collect();
+                        if types.len() == 1 {
+                            ty_snippet = snippet_opt(cx, types[0].span);
+                        }
+                    }
+                };
                 if let Some(spans) = get_spans(cx, opt_body_id, idx, &[("clone", ".to_owned()")]) {
                     span_lint_and_then(
                         cx,
@@ -172,17 +180,19 @@ fn check_fn(cx: &LateContext, decl: &FnDecl, fn_id: NodeId, opt_body_id: Option<
                          with non-Vec-based slices.",
                         |db| {
                             if let Some(ref snippet) = ty_snippet {
-                                db.span_suggestion(arg.span,
-                                                   "change this to",
-                                                   format!("&[{}]", snippet));
+                                db.span_suggestion(arg.span, "change this to", format!("&[{}]", snippet));
                             }
                             for (clonespan, suggestion) in spans {
-                                db.span_suggestion(clonespan,
-                                                   &snippet_opt(cx, clonespan).map_or("change the call to".into(),
-                                                        |x| Cow::Owned(format!("change `{}` to", x))),
-                                                   suggestion.into());
+                                db.span_suggestion(
+                                    clonespan,
+                                    &snippet_opt(cx, clonespan).map_or(
+                                        "change the call to".into(),
+                                        |x| Cow::Owned(format!("change `{}` to", x)),
+                                    ),
+                                    suggestion.into(),
+                                );
                             }
-                        }
+                        },
                     );
                 }
             } else if match_type(cx, ty, &paths::STRING) {
@@ -193,18 +203,47 @@ fn check_fn(cx: &LateContext, decl: &FnDecl, fn_id: NodeId, opt_body_id: Option<
                         arg.span,
                         "writing `&String` instead of `&str` involves a new object where a slice will do.",
                         |db| {
-                            db.span_suggestion(arg.span,
-                                               "change this to",
-                                               "&str".into());
+                            db.span_suggestion(arg.span, "change this to", "&str".into());
                             for (clonespan, suggestion) in spans {
-                                db.span_suggestion_short(clonespan,
-                                                   &snippet_opt(cx, clonespan).map_or("change the call to".into(),
-                                                        |x| Cow::Owned(format!("change `{}` to", x))),
-                                                   suggestion.into());
+                                db.span_suggestion_short(
+                                    clonespan,
+                                    &snippet_opt(cx, clonespan).map_or(
+                                        "change the call to".into(),
+                                        |x| Cow::Owned(format!("change `{}` to", x)),
+                                    ),
+                                    suggestion.into(),
+                                );
                             }
-                        }
+                        },
                     );
                 }
+            } else if match_type(cx, ty, &paths::COW) {
+                if_chain! {
+                    if let TyRptr(_, MutTy { ref ty, ..} ) = arg.node;
+                    if let TyPath(ref path) = ty.node;
+                    if let QPath::Resolved(None, ref pp) = *path;
+                    if let [ref bx] = *pp.segments;
+                    if let Some(ref params) = bx.args;
+                    if !params.parenthesized;
+                    if let Some(inner) = params.args.iter().find_map(|arg| match arg {
+                        GenericArg::Type(ty) => Some(ty),
+                        GenericArg::Lifetime(_) => None,
+                    });
+                    then {
+                        let replacement = snippet_opt(cx, inner.span);
+                        if let Some(r) = replacement {
+                            span_lint_and_then(
+                                cx,
+                                PTR_ARG,
+                                arg.span,
+                                "using a reference to `Cow` is not recommended.",
+                                |db| {
+                                    db.span_suggestion(arg.span, "change this to", "&".to_owned() + &r);
+                                },
+                            );
+                        }
+                    }
+                }
             }
         }
     }
@@ -242,9 +281,9 @@ fn get_rptr_lm(ty: &Ty) -> Option<(&Lifetime, Mutability, Span)> {
 }
 
 fn is_null_path(expr: &Expr) -> bool {
-    if let ExprCall(ref pathexp, ref args) = expr.node {
+    if let ExprKind::Call(ref pathexp, ref args) = expr.node {
         if args.is_empty() {
-            if let ExprPath(ref path) = pathexp.node {
+            if let ExprKind::Path(ref path) = pathexp.node {
                 return match_qpath(path, &paths::PTR_NULL) || match_qpath(path, &paths::PTR_NULL_MUT);
             }
         }