Merge pull request #143 from birkenfeld/more_methods

methods: move misc.StrToStringPass to MethodsPass

Author: Manishearth

src/lib.rs

@@ -37,7 +37,6 @@ pub mod returns;
 pub fn plugin_registrar(reg: &mut Registry) {
     reg.register_lint_pass(box types::TypePass as LintPassObject);
     reg.register_lint_pass(box misc::MiscPass as LintPassObject);
-    reg.register_lint_pass(box misc::StrToStringPass as LintPassObject);
     reg.register_lint_pass(box misc::TopLevelRefPass as LintPassObject);
     reg.register_lint_pass(box misc::CmpNan as LintPassObject);
     reg.register_lint_pass(box eq_op::EqOp as LintPassObject);
@@ -61,7 +60,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
     reg.register_lint_pass(box methods::MethodsPass as LintPassObject);
 
     reg.register_lint_group("clippy", vec![types::BOX_VEC, types::LINKEDLIST,
-                                           misc::SINGLE_MATCH, misc::STR_TO_STRING,
+                                           misc::SINGLE_MATCH,
                                            misc::TOPLEVEL_REF_ARG, eq_op::EQ_OP,
                                            bit_mask::BAD_BIT_MASK,
                                            bit_mask::INEFFECTIVE_BIT_MASK,
@@ -83,5 +82,6 @@ pub fn plugin_registrar(reg: &mut Registry) {
                                            misc::MODULO_ONE,
                                            methods::OPTION_UNWRAP_USED,
                                            methods::RESULT_UNWRAP_USED,
+                                           methods::STR_TO_STRING,
                                            ]);
 }

src/methods.rs

@@ -11,16 +11,19 @@ declare_lint!(pub OPTION_UNWRAP_USED, Warn,
               "Warn on using unwrap() on an Option value");
 declare_lint!(pub RESULT_UNWRAP_USED, Allow,
               "Warn on using unwrap() on a Result value");
+declare_lint!(pub STR_TO_STRING, Warn,
+              "Warn when a String could use to_owned() instead of to_string()");
 
 impl LintPass for MethodsPass {
     fn get_lints(&self) -> LintArray {
-        lint_array!(OPTION_UNWRAP_USED, RESULT_UNWRAP_USED)
+        lint_array!(OPTION_UNWRAP_USED, RESULT_UNWRAP_USED, STR_TO_STRING)
     }
 
     fn check_expr(&mut self, cx: &Context, expr: &Expr) {
         if let ExprMethodCall(ref ident, _, ref args) = expr.node {
+            let ref obj_ty = walk_ptrs_ty(cx.tcx.expr_ty(&*args[0])).sty;
             if ident.node.name == "unwrap" {
-                if let ty::TyEnum(did, _) = walk_ptrs_ty(cx.tcx.expr_ty(&*args[0])).sty {
+                if let ty::TyEnum(did, _) = *obj_ty {
                     if match_def_path(cx, did.did, &["core", "option", "Option"]) {
                         span_lint(cx, OPTION_UNWRAP_USED, expr.span,
                                   "used unwrap() on an Option value. If you don't want \
@@ -34,6 +37,11 @@ impl LintPass for MethodsPass {
                     }
                 }
             }
+            else if ident.node.name == "to_string" {
+                if let ty::TyStr = *obj_ty {
+                    span_lint(cx, STR_TO_STRING, expr.span, "`str.to_owned()` is faster");
+                }
+            }
         }
     }
 }

src/misc.rs

@@ -59,36 +59,6 @@ impl LintPass for MiscPass {
 }
 
 
-declare_lint!(pub STR_TO_STRING, Warn, "Warn when a String could use to_owned() instead of to_string()");
-
-#[allow(missing_copy_implementations)]
-pub struct StrToStringPass;
-
-impl LintPass for StrToStringPass {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(STR_TO_STRING)
-    }
-
-    fn check_expr(&mut self, cx: &Context, expr: &ast::Expr) {
-        match expr.node {
-            ast::ExprMethodCall(ref method, _, ref args)
-                if method.node.name == "to_string"
-                && is_str(cx, &*args[0]) => {
-                span_lint(cx, STR_TO_STRING, expr.span, "`str.to_owned()` is faster");
-            },
-            _ => ()
-        }
-
-        fn is_str(cx: &Context, expr: &ast::Expr) -> bool {
-            match walk_ptrs_ty(cx.tcx.expr_ty(expr)).sty {
-                ty::TyStr => true,
-                _ => false
-            }
-        }
-    }
-}
-
-
 declare_lint!(pub TOPLEVEL_REF_ARG, Warn, "Warn about pattern matches with top-level `ref` bindings");
 
 #[allow(missing_copy_implementations)]