X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;ds=sidebyside;f=src%2Ftools%2Fclippy%2Fclippy_lints%2Fsrc%2Fcopies.rs;h=8b79f1600aeb0ab7542ea6d3286b68d8d1159f45;hb=9246e8867cf6f6af0791a611afecec4687c0b038;hp=73ce656ad151437d490bf435e525c9d8c1797258;hpb=a34c0797528172ede89480e3033f7a5e71ea4735;p=rust.git

diff --git a/src/tools/clippy/clippy_lints/src/copies.rs b/src/tools/clippy/clippy_lints/src/copies.rs
index 73ce656ad15..8b79f1600ae 100644
--- a/src/tools/clippy/clippy_lints/src/copies.rs
+++ b/src/tools/clippy/clippy_lints/src/copies.rs
@@ -7,10 +7,10 @@
 use if_chain::if_chain;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, DiagnosticBuilder};
-use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
+use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Block, Expr, ExprKind, HirId};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::hir::map::Map;
+use rustc_middle::hir::nested_filter;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{source_map::Span, symbol::Symbol, BytePos};
 use std::borrow::Cow;
@@ -183,7 +183,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
                 lint_same_cond(cx, &conds);
                 lint_same_fns_in_if_cond(cx, &conds);
                 // Block duplication
-                lint_same_then_else(cx, &blocks, conds.len() == blocks.len(), expr);
+                lint_same_then_else(cx, &conds, &blocks, conds.len() == blocks.len(), expr);
             }
         }
     }
@@ -192,6 +192,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
 /// Implementation of `BRANCHES_SHARING_CODE` and `IF_SAME_THEN_ELSE` if the blocks are equal.
 fn lint_same_then_else<'tcx>(
     cx: &LateContext<'tcx>,
+    conds: &[&'tcx Expr<'_>],
     blocks: &[&Block<'tcx>],
     has_conditional_else: bool,
     expr: &'tcx Expr<'_>,
@@ -204,7 +205,7 @@ fn lint_same_then_else<'tcx>(
     // Check if each block has shared code
     let has_expr = blocks[0].expr.is_some();
 
-    let (start_eq, mut end_eq, expr_eq) = if let Some(block_eq) = scan_block_for_eq(cx, blocks) {
+    let (start_eq, mut end_eq, expr_eq) = if let Some(block_eq) = scan_block_for_eq(cx, conds, blocks) {
         (block_eq.start_eq, block_eq.end_eq, block_eq.expr_eq)
     } else {
         return;
@@ -316,14 +317,14 @@ struct BlockEqual {
 
 /// This function can also trigger the `IF_SAME_THEN_ELSE` in which case it'll return `None` to
 /// abort any further processing and avoid duplicate lint triggers.
-fn scan_block_for_eq(cx: &LateContext<'_>, blocks: &[&Block<'_>]) -> Option<BlockEqual> {
+fn scan_block_for_eq(cx: &LateContext<'_>, conds: &[&Expr<'_>], blocks: &[&Block<'_>]) -> Option<BlockEqual> {
     let mut start_eq = usize::MAX;
     let mut end_eq = usize::MAX;
     let mut expr_eq = true;
-    let mut iter = blocks.windows(2);
-    while let Some(&[win0, win1]) = iter.next() {
-        let l_stmts = win0.stmts;
-        let r_stmts = win1.stmts;
+    let mut iter = blocks.windows(2).enumerate();
+    while let Some((i, &[block0, block1])) = iter.next() {
+        let l_stmts = block0.stmts;
+        let r_stmts = block1.stmts;
 
         // `SpanlessEq` now keeps track of the locals and is therefore context sensitive clippy#6752.
         // The comparison therefore needs to be done in a way that builds the correct context.
@@ -340,22 +341,26 @@ fn scan_block_for_eq(cx: &LateContext<'_>, blocks: &[&Block<'_>]) -> Option<Bloc
             it1.zip(it2)
                 .fold(0, |acc, (l, r)| if evaluator.eq_stmt(l, r) { acc + 1 } else { 0 })
         };
-        let block_expr_eq = both(&win0.expr, &win1.expr, |l, r| evaluator.eq_expr(l, r));
+        let block_expr_eq = both(&block0.expr, &block1.expr, |l, r| evaluator.eq_expr(l, r));
 
         // IF_SAME_THEN_ELSE
         if_chain! {
             if block_expr_eq;
             if l_stmts.len() == r_stmts.len();
             if l_stmts.len() == current_start_eq;
-            if !is_lint_allowed(cx, IF_SAME_THEN_ELSE, win0.hir_id);
-            if !is_lint_allowed(cx, IF_SAME_THEN_ELSE, win1.hir_id);
+            // `conds` may have one last item than `blocks`.
+            // Any `i` from `blocks.windows(2)` will exist in `conds`, but `i+1` may not exist on the last iteration.
+            if !matches!(conds[i].kind, ExprKind::Let(..));
+            if !matches!(conds.get(i + 1).map(|e| &e.kind), Some(ExprKind::Let(..)));
+            if !is_lint_allowed(cx, IF_SAME_THEN_ELSE, block0.hir_id);
+            if !is_lint_allowed(cx, IF_SAME_THEN_ELSE, block1.hir_id);
             then {
                 span_lint_and_note(
                     cx,
                     IF_SAME_THEN_ELSE,
-                    win0.span,
+                    block0.span,
                     "this `if` has identical blocks",
-                    Some(win1.span),
+                    Some(block1.span),
                     "same as this",
                 );
 
@@ -561,10 +566,10 @@ fn new(cx: &'a LateContext<'tcx>) -> Self {
 }
 
 impl<'a, 'tcx> Visitor<'tcx> for UsedValueFinderVisitor<'a, 'tcx> {
-    type Map = Map<'tcx>;
+    type NestedFilter = nested_filter::All;
 
-    fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
-        NestedVisitorMap::All(self.cx.tcx.hir())
+    fn nested_visit_map(&mut self) -> Self::Map {
+        self.cx.tcx.hir()
     }
 
     fn visit_local(&mut self, l: &'tcx rustc_hir::Local<'tcx>) {