Auto merge of rust-lang#9469 - Alexendoo:expr-field-visitor, r=giraffate

Fix FormatArgsExpn parsing of FormatSpec positions

Woops, forgot visitors don't walk themselves

Fixes rust-lang#9468

r? `@giraffate`

changelog: none

Author: bors

clippy_utils/src/macros.rs

@@ -7,7 +7,7 @@ use crate::visitors::expr_visitor_no_bodies;
 use arrayvec::ArrayVec;
 use itertools::{izip, Either, Itertools};
 use rustc_ast::ast::LitKind;
-use rustc_hir::intravisit::Visitor;
+use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{self as hir, Expr, ExprField, ExprKind, HirId, Node, QPath};
 use rustc_lexer::unescape::unescape_literal;
 use rustc_lexer::{tokenize, unescape, LiteralKind, TokenKind};
@@ -515,7 +515,7 @@ impl<'tcx> Visitor<'tcx> for ParamPosition {
             sym::width => {
                 self.width = parse_count(field.expr);
             },
-            _ => {},
+            _ => walk_expr(self, field.expr),
         }
     }
 }

tests/ui/explicit_write.fixed

@@ -36,6 +36,8 @@ fn main() {
         eprintln!("with {} {}", 2, value);
         eprintln!("with {value}");
         eprintln!("macro arg {}", one!());
+        let width = 2;
+        eprintln!("{:w$}", value, w = width);
     }
     // these should not warn, different destination
     {

tests/ui/explicit_write.rs

@@ -36,6 +36,8 @@ fn main() {
         writeln!(std::io::stderr(), "with {} {}", 2, value).unwrap();
         writeln!(std::io::stderr(), "with {value}").unwrap();
         writeln!(std::io::stderr(), "macro arg {}", one!()).unwrap();
+        let width = 2;
+        writeln!(std::io::stderr(), "{:w$}", value, w = width).unwrap();
     }
     // these should not warn, different destination
     {

tests/ui/explicit_write.stderr

@@ -72,5 +72,11 @@ error: use of `writeln!(stderr(), ...).unwrap()`
 LL |         writeln!(std::io::stderr(), "macro arg {}", one!()).unwrap();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("macro arg {}", one!())`
 
-error: aborting due to 12 previous errors
+error: use of `writeln!(stderr(), ...).unwrap()`
+  --> $DIR/explicit_write.rs:40:9
+   |
+LL |         writeln!(std::io::stderr(), "{:w$}", value, w = width).unwrap();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `eprintln!("{:w$}", value, w = width)`
+
+error: aborting due to 13 previous errors