Add desugaring mark to while loop

camsteffen · camsteffen · commit 67ea84d97a49 · 2021-10-02T17:41:14.000-05:00
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
@@ -100,10 +100,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 ExprKind::If(ref cond, ref then, ref else_opt) => {
                     self.lower_expr_if(cond, then, else_opt.as_deref())
                 }
-                ExprKind::While(ref cond, ref body, opt_label) => self
-                    .with_loop_scope(e.id, |this| {
-                        this.lower_expr_while_in_loop_scope(e.span, cond, body, opt_label)
-                    }),
+                ExprKind::While(ref cond, ref body, opt_label) => {
+                    self.with_loop_scope(e.id, |this| {
+                        let span =
+                            this.mark_span_with_reason(DesugaringKind::WhileLoop, e.span, None);
+                        this.lower_expr_while_in_loop_scope(span, cond, body, opt_label)
+                    })
+                }
                 ExprKind::Loop(ref body, opt_label) => self.with_loop_scope(e.id, |this| {
                     hir::ExprKind::Loop(
                         this.lower_block(body, false),
diff --git a/compiler/rustc_middle/src/lint.rs b/compiler/rustc_middle/src/lint.rs
@@ -389,9 +389,9 @@ pub fn struct_lint_level<'s, 'd>(
 pub fn in_external_macro(sess: &Session, span: Span) -> bool {
     let expn_data = span.ctxt().outer_expn_data();
     match expn_data.kind {
-        ExpnKind::Inlined | ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop(_)) => {
-            false
-        }
+        ExpnKind::Inlined
+        | ExpnKind::Root
+        | ExpnKind::Desugaring(DesugaringKind::ForLoop(_) | DesugaringKind::WhileLoop) => false,
         ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => true, // well, it's "external"
         ExpnKind::Macro(MacroKind::Bang, _) => {
             // Dummy span for the `def_site` means it's an external macro.
diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs
@@ -1101,6 +1101,7 @@ pub enum DesugaringKind {
     Await,
     ForLoop(ForLoopLoc),
     LetElse,
+    WhileLoop,
 }
 
 /// A location in the desugaring of a `for` loop
@@ -1122,6 +1123,7 @@ impl DesugaringKind {
             DesugaringKind::OpaqueTy => "`impl Trait`",
             DesugaringKind::ForLoop(_) => "`for` loop",
             DesugaringKind::LetElse => "`let...else`",
+            DesugaringKind::WhileLoop => "`while` loop",
         }
     }
 }
diff --git a/compiler/rustc_typeck/src/check/coercion.rs b/compiler/rustc_typeck/src/check/coercion.rs
@@ -54,7 +54,7 @@ use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, ToPredicate, Ty, TypeAndMut};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
-use rustc_span::{self, BytePos, Span};
+use rustc_span::{self, BytePos, DesugaringKind, Span};
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt;
 use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode};
@@ -1536,8 +1536,10 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 // If the block is from an external macro or try (`?`) desugaring, then
                 // do not suggest adding a semicolon, because there's nowhere to put it.
                 // See issues #81943 and #87051.
-                if cond_expr.span.desugaring_kind().is_none()
-                    && !in_external_macro(fcx.tcx.sess, cond_expr.span)
+                if matches!(
+                    cond_expr.span.desugaring_kind(),
+                    None | Some(DesugaringKind::WhileLoop)
+                ) && !in_external_macro(fcx.tcx.sess, cond_expr.span)
                     && !matches!(
                         cond_expr.kind,
                         hir::ExprKind::Match(.., hir::MatchSource::TryDesugar)
diff --git a/src/tools/clippy/tests/ui/crashes/issues_loop_mut_cond.rs b/src/tools/clippy/tests/ui/crashes/issues_loop_mut_cond.rs
@@ -1,4 +1,3 @@
-#![allow(clippy::blocks_in_if_conditions)]
 #![allow(dead_code)]
 
 /// Issue: https://github.com/rust-lang/rust-clippy/issues/2596
diff --git a/src/tools/clippy/tests/ui/infinite_loop.rs b/src/tools/clippy/tests/ui/infinite_loop.rs
@@ -1,5 +1,3 @@
-#![allow(clippy::blocks_in_if_conditions)]
-
 fn fn_val(i: i32) -> i32 {
     unimplemented!()
 }
diff --git a/src/tools/clippy/tests/ui/infinite_loop.stderr b/src/tools/clippy/tests/ui/infinite_loop.stderr
@@ -1,5 +1,5 @@
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:22:11
+  --> $DIR/infinite_loop.rs:20:11
    |
 LL |     while y < 10 {
    |           ^^^^^^
@@ -8,71 +8,71 @@ LL |     while y < 10 {
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:27:11
+  --> $DIR/infinite_loop.rs:25:11
    |
 LL |     while y < 10 && x < 3 {
    |           ^^^^^^^^^^^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:34:11
+  --> $DIR/infinite_loop.rs:32:11
    |
 LL |     while !cond {
    |           ^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:78:11
+  --> $DIR/infinite_loop.rs:76:11
    |
 LL |     while i < 3 {
    |           ^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:83:11
+  --> $DIR/infinite_loop.rs:81:11
    |
 LL |     while i < 3 && j > 0 {
    |           ^^^^^^^^^^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:87:11
+  --> $DIR/infinite_loop.rs:85:11
    |
 LL |     while i < 3 {
    |           ^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:102:11
+  --> $DIR/infinite_loop.rs:100:11
    |
 LL |     while i < 3 {
    |           ^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:107:11
+  --> $DIR/infinite_loop.rs:105:11
    |
 LL |     while i < 3 {
    |           ^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:173:15
+  --> $DIR/infinite_loop.rs:171:15
    |
 LL |         while self.count < n {
    |               ^^^^^^^^^^^^^^
    |
    = note: this may lead to an infinite or to a never running loop
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:181:11
+  --> $DIR/infinite_loop.rs:179:11
    |
 LL |     while y < 10 {
    |           ^^^^^^
@@ -82,7 +82,7 @@ LL |     while y < 10 {
    = help: rewrite it as `if cond { loop { } }`
 
 error: variables in the condition are not mutated in the loop body
-  --> $DIR/infinite_loop.rs:188:11
+  --> $DIR/infinite_loop.rs:186:11
    |
 LL |     while y < 10 {
    |           ^^^^^^

Original file line number	Diff line number	Diff line change
`@@ -1101,6 +1101,7 @@ pub enum DesugaringKind {`
`1101`	`1101`	`Await,`
`1102`	`1102`	`ForLoop(ForLoopLoc),`
`1103`	`1103`	`LetElse,`
	`1104`	`+ WhileLoop,`
`1104`	`1105`	`}`
`1105`	`1106`
`1106`	`1107`	/// A location in the desugaring of a `for` loop
`@@ -1122,6 +1123,7 @@ impl DesugaringKind {`
`1122`	`1123`	DesugaringKind::OpaqueTy => "`impl Trait`",
`1123`	`1124`	DesugaringKind::ForLoop(_) => "`for` loop",
`1124`	`1125`	DesugaringKind::LetElse => "`let...else`",
	`1126`	+ DesugaringKind::WhileLoop => "`while` loop",
`1125`	`1127`	`}`
`1126`	`1128`	`}`
`1127`	`1129`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,3 @@`
`1`		`-#![allow(clippy::blocks_in_if_conditions)]`
`2`	`1`	`#![allow(dead_code)]`
`3`	`2`
`4`	`3`	`/// Issue: https://github.com/rust-lang/rust-clippy/issues/2596`
Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,3 @@`
`1`		`-#![allow(clippy::blocks_in_if_conditions)]`
`2`		`-`
`3`	`1`	`fn fn_val(i: i32) -> i32 {`
`4`	`2`	`unimplemented!()`
`5`	`3`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`error: variables in the condition are not mutated in the loop body`
`2`		`- --> $DIR/infinite_loop.rs:22:11`
	`2`	`+ --> $DIR/infinite_loop.rs:20:11`
`3`	`3`	`\|`
`4`	`4`	`LL \| while y < 10 {`
`5`	`5`	`\| ^^^^^^`
`@@ -8,71 +8,71 @@ LL \| while y < 10 {`
`8`	`8`	`= note: this may lead to an infinite or to a never running loop`
`9`	`9`
`10`	`10`	`error: variables in the condition are not mutated in the loop body`
`11`		`- --> $DIR/infinite_loop.rs:27:11`
	`11`	`+ --> $DIR/infinite_loop.rs:25:11`
`12`	`12`	`\|`
`13`	`13`	`LL \| while y < 10 && x < 3 {`
`14`	`14`	`\| ^^^^^^^^^^^^^^^`
`15`	`15`	`\|`
`16`	`16`	`= note: this may lead to an infinite or to a never running loop`
`17`	`17`
`18`	`18`	`error: variables in the condition are not mutated in the loop body`
`19`		`- --> $DIR/infinite_loop.rs:34:11`
	`19`	`+ --> $DIR/infinite_loop.rs:32:11`
`20`	`20`	`\|`
`21`	`21`	`LL \| while !cond {`
`22`	`22`	`\| ^^^^^`
`23`	`23`	`\|`
`24`	`24`	`= note: this may lead to an infinite or to a never running loop`
`25`	`25`
`26`	`26`	`error: variables in the condition are not mutated in the loop body`
`27`		`- --> $DIR/infinite_loop.rs:78:11`
	`27`	`+ --> $DIR/infinite_loop.rs:76:11`
`28`	`28`	`\|`
`29`	`29`	`LL \| while i < 3 {`
`30`	`30`	`\| ^^^^^`
`31`	`31`	`\|`
`32`	`32`	`= note: this may lead to an infinite or to a never running loop`
`33`	`33`
`34`	`34`	`error: variables in the condition are not mutated in the loop body`
`35`		`- --> $DIR/infinite_loop.rs:83:11`
	`35`	`+ --> $DIR/infinite_loop.rs:81:11`
`36`	`36`	`\|`
`37`	`37`	`LL \| while i < 3 && j > 0 {`
`38`	`38`	`\| ^^^^^^^^^^^^^^`
`39`	`39`	`\|`
`40`	`40`	`= note: this may lead to an infinite or to a never running loop`
`41`	`41`
`42`	`42`	`error: variables in the condition are not mutated in the loop body`
`43`		`- --> $DIR/infinite_loop.rs:87:11`
	`43`	`+ --> $DIR/infinite_loop.rs:85:11`
`44`	`44`	`\|`
`45`	`45`	`LL \| while i < 3 {`
`46`	`46`	`\| ^^^^^`
`47`	`47`	`\|`
`48`	`48`	`= note: this may lead to an infinite or to a never running loop`
`49`	`49`
`50`	`50`	`error: variables in the condition are not mutated in the loop body`
`51`		`- --> $DIR/infinite_loop.rs:102:11`
	`51`	`+ --> $DIR/infinite_loop.rs:100:11`
`52`	`52`	`\|`
`53`	`53`	`LL \| while i < 3 {`
`54`	`54`	`\| ^^^^^`
`55`	`55`	`\|`
`56`	`56`	`= note: this may lead to an infinite or to a never running loop`
`57`	`57`
`58`	`58`	`error: variables in the condition are not mutated in the loop body`
`59`		`- --> $DIR/infinite_loop.rs:107:11`
	`59`	`+ --> $DIR/infinite_loop.rs:105:11`
`60`	`60`	`\|`
`61`	`61`	`LL \| while i < 3 {`
`62`	`62`	`\| ^^^^^`
`63`	`63`	`\|`
`64`	`64`	`= note: this may lead to an infinite or to a never running loop`
`65`	`65`
`66`	`66`	`error: variables in the condition are not mutated in the loop body`
`67`		`- --> $DIR/infinite_loop.rs:173:15`
	`67`	`+ --> $DIR/infinite_loop.rs:171:15`
`68`	`68`	`\|`
`69`	`69`	`LL \| while self.count < n {`
`70`	`70`	`\| ^^^^^^^^^^^^^^`
`71`	`71`	`\|`
`72`	`72`	`= note: this may lead to an infinite or to a never running loop`
`73`	`73`
`74`	`74`	`error: variables in the condition are not mutated in the loop body`
`75`		`- --> $DIR/infinite_loop.rs:181:11`
	`75`	`+ --> $DIR/infinite_loop.rs:179:11`
`76`	`76`	`\|`
`77`	`77`	`LL \| while y < 10 {`
`78`	`78`	`\| ^^^^^^`
`@@ -82,7 +82,7 @@ LL \| while y < 10 {`
`82`	`82`	= help: rewrite it as `if cond { loop { } }`
`83`	`83`
`84`	`84`	`error: variables in the condition are not mutated in the loop body`
`85`		`- --> $DIR/infinite_loop.rs:188:11`
	`85`	`+ --> $DIR/infinite_loop.rs:186:11`
`86`	`86`	`\|`
`87`	`87`	`LL \| while y < 10 {`
`88`	`88`	`\| ^^^^^^`