Auto merge of #73756 - Manishearth:rollup-aehswb2, r=Manishearth

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

diff --git a/clippy_lints/src/format.rs b/clippy_lints/src/format.rs
index 052684818fc15a8e53e5a3985f707666e0748f27..58cf0027ea4d4183f9c4468f3ac0de3a425e0638 100644 (file)
--- a/clippy_lints/src/format.rs
+++ b/clippy_lints/src/format.rs
@@ -1,16 +1,15 @@
 use crate::utils::paths;
 use crate::utils::{
-    is_expn_of, last_path_segment, match_def_path, match_function_call, match_type, snippet, span_lint_and_then,
-    walk_ptrs_ty,
+    is_expn_of, is_type_diagnostic_item, last_path_segment, match_def_path, match_function_call, snippet,
+    span_lint_and_then, walk_ptrs_ty,
 };
 use if_chain::if_chain;
-use rustc::declare_lint_pass;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintContext, LintPass};
+use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
-use rustc_session::declare_tool_lint;
-use syntax::ast::LitKind;
-use syntax::source_map::Span;
+use rustc_hir::{Arm, BorrowKind, Expr, ExprKind, MatchSource, PatKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for the use of `format!("string literal with no
@@ -26,9 +25,13 @@
     ///
     /// **Examples:**
     /// ```rust
+    ///
+    /// // Bad
     /// # let foo = "foo";
-    /// format!("foo");
     /// format!("{}", foo);
+    ///
+    /// // Good
+    /// format!("foo");
     /// ```
     pub USELESS_FORMAT,
     complexity,
@@ -38,7 +41,7 @@
 declare_lint_pass!(UselessFormat => [USELESS_FORMAT]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessFormat {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
         let span = match is_expn_of(expr.span, "format") {
             Some(s) if !s.from_expansion() => s,
             _ => return,
@@ -46,9 +49,9 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
 
         // Operate on the only argument of `alloc::fmt::format`.
         if let Some(sugg) = on_new_v1(cx, expr) {
-            span_useless_format(cx, span, "consider using .to_string()", sugg);
+            span_useless_format(cx, span, "consider using `.to_string()`", sugg);
         } else if let Some(sugg) = on_new_v1_fmt(cx, expr) {
-            span_useless_format(cx, span, "consider using .to_string()", sugg);
+            span_useless_format(cx, span, "consider using `.to_string()`", sugg);
         }
     }
 }
@@ -62,8 +65,8 @@ fn span_useless_format<T: LintContext>(cx: &T, span: Span, help: &str, mut sugg:
         sugg.push(';');
     }
 
-    span_lint_and_then(cx, USELESS_FORMAT, span, "useless use of `format!`", |db| {
-        db.span_suggestion(
+    span_lint_and_then(cx, USELESS_FORMAT, span, "useless use of `format!`", |diag| {
+        diag.span_suggestion(
             to_replace,
             help,
             sugg,
@@ -72,7 +75,11 @@ fn span_useless_format<T: LintContext>(cx: &T, span: Span, help: &str, mut sugg:
     });
 }
 
-fn on_argumentv1_new<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr, arms: &'tcx [Arm]) -> Option<String> {
+fn on_argumentv1_new<'a, 'tcx>(
+    cx: &LateContext<'a, 'tcx>,
+    expr: &'tcx Expr<'_>,
+    arms: &'tcx [Arm<'_>],
+) -> Option<String> {
     if_chain! {
         if let ExprKind::AddrOf(BorrowKind::Ref, _, ref format_args) = expr.kind;
         if let ExprKind::Array(ref elems) = arms[0].body.kind;
@@ -81,14 +88,14 @@ fn on_argumentv1_new<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr, arm
         // matches `core::fmt::Display::fmt`
         if args.len() == 2;
         if let ExprKind::Path(ref qpath) = args[1].kind;
-        if let Some(did) = cx.tables.qpath_res(qpath, args[1].hir_id).opt_def_id();
+        if let Some(did) = cx.tables().qpath_res(qpath, args[1].hir_id).opt_def_id();
         if match_def_path(cx, did, &paths::DISPLAY_FMT_METHOD);
         // check `(arg0,)` in match block
         if let PatKind::Tuple(ref pats, None) = arms[0].pat.kind;
         if pats.len() == 1;
         then {
-            let ty = walk_ptrs_ty(cx.tables.pat_ty(&pats[0]));
-            if ty.kind != rustc::ty::Str && !match_type(cx, ty, &paths::STRING) {
+            let ty = walk_ptrs_ty(cx.tables().pat_ty(&pats[0]));
+            if ty.kind != rustc_middle::ty::Str && !is_type_diagnostic_item(cx, ty, sym!(string_type)) {
                 return None;
             }
             if let ExprKind::Lit(ref lit) = format_args.kind {
@@ -97,7 +104,7 @@ fn on_argumentv1_new<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr, arm
                 }
             } else {
                 let snip = snippet(cx, format_args.span, "<arg>");
-                if let ExprKind::MethodCall(ref path, _, _) = format_args.kind {
+                if let ExprKind::MethodCall(ref path, _, _, _) = format_args.kind {
                     if path.ident.name == sym!(to_string) {
                         return Some(format!("{}", snip));
                     }
@@ -111,7 +118,7 @@ fn on_argumentv1_new<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr, arm
     None
 }
 
-fn on_new_v1<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) -> Option<String> {
+fn on_new_v1<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> Option<String> {
     if_chain! {
         if let Some(args) = match_function_call(cx, expr, &paths::FMT_ARGUMENTS_NEW_V1);
         if args.len() == 2;
@@ -138,7 +145,7 @@ fn on_new_v1<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) -> Option<S
     None
 }
 
-fn on_new_v1_fmt<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) -> Option<String> {
+fn on_new_v1_fmt<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> Option<String> {
     if_chain! {
         if let Some(args) = match_function_call(cx, expr, &paths::FMT_ARGUMENTS_NEW_V1_FORMATTED);
         if args.len() == 3;
@@ -172,7 +179,7 @@ fn on_new_v1_fmt<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) -> Opti
 ///    ...,
 /// }]
 /// ```
-fn check_unformatted(expr: &Expr) -> bool {
+fn check_unformatted(expr: &Expr<'_>) -> bool {
     if_chain! {
         if let ExprKind::AddrOf(BorrowKind::Ref, _, ref expr) = expr.kind;
         if let ExprKind::Array(ref exprs) = expr.kind;