Rollup merge of rust-lang#93595 - compiler-errors:ice-on-lifetime-arg, r=jackh726

fix ICE when parsing lifetime as function argument

I don't really like this, but we basically need to emit an error instead of just delaying an bug, because there are too many places in the AST that aren't covered by my previous PRs...

cc: rust-lang#93282 (comment)

Author: matthiaskrgr

compiler/rustc_parse/src/parser/expr.rs

@@ -1457,9 +1457,9 @@ impl<'a> Parser<'a> {
         } else if self.check(&token::OpenDelim(token::Brace)) || self.token.is_whole_block() {
             self.parse_block_expr(label, lo, BlockCheckMode::Default, attrs)
         } else if !ate_colon && (self.check(&TokenKind::Comma) || self.check(&TokenKind::Gt)) {
-            // We're probably inside of a `Path<'a>` that needs a turbofish, so suppress the
-            // "must be followed by a colon" error, and the "expected one of" error.
-            self.diagnostic().delay_span_bug(lo, "this label wasn't parsed correctly");
+            // We're probably inside of a `Path<'a>` that needs a turbofish
+            let msg = "expected `while`, `for`, `loop` or `{` after a label";
+            self.struct_span_err(self.token.span, msg).span_label(self.token.span, msg).emit();
             consume_colon = false;
             Ok(self.mk_expr_err(lo))
         } else {

src/test/ui/parser/issues/issue-93282.rs

@@ -1,4 +1,15 @@
 fn main() {
     f<'a,>
     //~^ ERROR expected
+    //~| ERROR expected
+}
+
+fn bar(a: usize, b: usize) -> usize {
+    a + b
+}
+
+fn foo() {
+    let x = 1;
+    bar('y, x);
+    //~^ ERROR expected
 }

src/test/ui/parser/issues/issue-93282.stderr

@@ -1,3 +1,9 @@
+error: expected `while`, `for`, `loop` or `{` after a label
+  --> $DIR/issue-93282.rs:2:9
+   |
+LL |     f<'a,>
+   |         ^ expected `while`, `for`, `loop` or `{` after a label
+
 error: expected one of `.`, `:`, `;`, `?`, `for`, `loop`, `while`, `{`, `}`, or an operator, found `,`
   --> $DIR/issue-93282.rs:2:9
    |
@@ -9,5 +15,11 @@ help: use `::<...>` instead of `<...>` to specify lifetime, type, or const argum
 LL |     f::<'a,>
    |      ++
 
-error: aborting due to previous error
+error: expected `while`, `for`, `loop` or `{` after a label
+  --> $DIR/issue-93282.rs:13:11
+   |
+LL |     bar('y, x);
+   |           ^ expected `while`, `for`, `loop` or `{` after a label
+
+error: aborting due to 3 previous errors
 

src/test/ui/parser/require-parens-for-chained-comparison.rs

@@ -22,10 +22,12 @@ fn main() {
     let _ = f<'_, i8>();
     //~^ ERROR expected one of
     //~| HELP use `::<...>` instead of `<...>` to specify lifetime, type, or const arguments
+    //~| ERROR expected
 
     f<'_>();
     //~^ comparison operators cannot be chained
     //~| HELP use `::<...>` instead of `<...>` to specify lifetime, type, or const arguments
+    //~| ERROR expected
 
     let _ = f<u8>;
     //~^ ERROR comparison operators cannot be chained

src/test/ui/parser/require-parens-for-chained-comparison.stderr

@@ -53,6 +53,12 @@ help: use `::<...>` instead of `<...>` to specify lifetime, type, or const argum
 LL |     let _ = f::<u8, i8>();
    |              ++
 
+error: expected `while`, `for`, `loop` or `{` after a label
+  --> $DIR/require-parens-for-chained-comparison.rs:22:17
+   |
+LL |     let _ = f<'_, i8>();
+   |                 ^ expected `while`, `for`, `loop` or `{` after a label
+
 error: expected one of `.`, `:`, `;`, `?`, `else`, `for`, `loop`, `while`, `{`, or an operator, found `,`
   --> $DIR/require-parens-for-chained-comparison.rs:22:17
    |
@@ -64,8 +70,14 @@ help: use `::<...>` instead of `<...>` to specify lifetime, type, or const argum
 LL |     let _ = f::<'_, i8>();
    |              ++
 
+error: expected `while`, `for`, `loop` or `{` after a label
+  --> $DIR/require-parens-for-chained-comparison.rs:27:9
+   |
+LL |     f<'_>();
+   |         ^ expected `while`, `for`, `loop` or `{` after a label
+
 error: comparison operators cannot be chained
-  --> $DIR/require-parens-for-chained-comparison.rs:26:6
+  --> $DIR/require-parens-for-chained-comparison.rs:27:6
    |
 LL |     f<'_>();
    |      ^  ^
@@ -76,13 +88,13 @@ LL |     f::<'_>();
    |      ++
 
 error: comparison operators cannot be chained
-  --> $DIR/require-parens-for-chained-comparison.rs:30:14
+  --> $DIR/require-parens-for-chained-comparison.rs:32:14
    |
 LL |     let _ = f<u8>;
    |              ^  ^
    |
    = help: use `::<...>` instead of `<...>` to specify lifetime, type, or const arguments
    = help: or use `(...)` if you meant to specify fn arguments
 
-error: aborting due to 8 previous errors
+error: aborting due to 10 previous errors