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Silence some invalid type params in field errors
Reduce the verbosity of forgetting parentheses in methods with type parameters by keeping that AST information until HIR type-checking.
1 parent 97d47a5 commit ce25b7c

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23 files changed

+57
-43
lines changed

23 files changed

+57
-43
lines changed

‎src/librustc_ast_lowering/expr.rs

+3-1
Original file line numberDiff line numberDiff line change
@@ -129,7 +129,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
129129
self.lower_expr(el),
130130
self.lower_expr(er),
131131
),
132-
ExprKind::Field(ref el, ident) => hir::ExprKind::Field(self.lower_expr(el), ident),
132+
ExprKind::Field(ref el, ident, args) => {
133+
hir::ExprKind::Field(self.lower_expr(el), ident, args)
134+
}
133135
ExprKind::Index(ref el, ref er) => {
134136
hir::ExprKind::Index(self.lower_expr(el), self.lower_expr(er))
135137
}

‎src/librustc_ast_pretty/pprust.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -2025,7 +2025,7 @@ impl<'a> State<'a> {
20252025
self.word_space("=");
20262026
self.print_expr_maybe_paren(rhs, prec);
20272027
}
2028-
ast::ExprKind::Field(ref expr, ident) => {
2028+
ast::ExprKind::Field(ref expr, ident, _) => {
20292029
self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
20302030
self.s.word(".");
20312031
self.print_ident(ident);

‎src/librustc_hir/hir.rs

+3-2
Original file line numberDiff line numberDiff line change
@@ -1396,7 +1396,7 @@ impl Expr<'_> {
13961396

13971397
ExprKind::Unary(UnOp::UnDeref, _) => true,
13981398

1399-
ExprKind::Field(ref base, _) | ExprKind::Index(ref base, _) => {
1399+
ExprKind::Field(ref base, ..) | ExprKind::Index(ref base, _) => {
14001400
allow_projections_from(base) || base.is_place_expr(allow_projections_from)
14011401
}
14021402

@@ -1588,7 +1588,8 @@ pub enum ExprKind<'hir> {
15881588
/// E.g., `a += 1`.
15891589
AssignOp(BinOp, &'hir Expr<'hir>, &'hir Expr<'hir>),
15901590
/// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct or tuple field.
1591-
Field(&'hir Expr<'hir>, Ident),
1591+
/// The optional `Span` points at an *invalid* type parameter in the field expression.
1592+
Field(&'hir Expr<'hir>, Ident, Option<Span>),
15921593
/// An indexing operation (`foo[2]`).
15931594
Index(&'hir Expr<'hir>, &'hir Expr<'hir>),
15941595

‎src/librustc_hir/intravisit.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -1110,7 +1110,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
11101110
visitor.visit_expr(right_expression);
11111111
visitor.visit_expr(left_expression);
11121112
}
1113-
ExprKind::Field(ref subexpression, ident) => {
1113+
ExprKind::Field(ref subexpression, ident, _) => {
11141114
visitor.visit_expr(subexpression);
11151115
visitor.visit_ident(ident);
11161116
}

‎src/librustc_hir/print.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -1344,7 +1344,7 @@ impl<'a> State<'a> {
13441344
self.word_space("=");
13451345
self.print_expr_maybe_paren(&rhs, prec);
13461346
}
1347-
hir::ExprKind::Field(ref expr, ident) => {
1347+
hir::ExprKind::Field(ref expr, ident, _) => {
13481348
self.print_expr_maybe_paren(expr, parser::PREC_POSTFIX);
13491349
self.s.word(".");
13501350
self.print_ident(ident);
@@ -2315,7 +2315,7 @@ fn contains_exterior_struct_lit(value: &hir::Expr<'_>) -> bool {
23152315
hir::ExprKind::Unary(_, ref x)
23162316
| hir::ExprKind::Cast(ref x, _)
23172317
| hir::ExprKind::Type(ref x, _)
2318-
| hir::ExprKind::Field(ref x, _)
2318+
| hir::ExprKind::Field(ref x, ..)
23192319
| hir::ExprKind::Index(ref x, _) => {
23202320
// `&X { y: 1 }, X { y: 1 }.y`
23212321
contains_exterior_struct_lit(&x)

‎src/librustc_parse/parser/expr.rs

+6-10
Original file line numberDiff line numberDiff line change
@@ -786,7 +786,7 @@ impl<'a> Parser<'a> {
786786
) -> P<Expr> {
787787
let span = self.token.span;
788788
self.bump();
789-
let field = ExprKind::Field(base, Ident::new(field, span));
789+
let field = ExprKind::Field(base, Ident::new(field, span), None);
790790
self.expect_no_suffix(span, "a tuple index", suffix);
791791
self.mk_expr(lo.to(span), field, AttrVec::new())
792792
}
@@ -825,16 +825,12 @@ impl<'a> Parser<'a> {
825825
Ok(self.mk_expr(span, ExprKind::MethodCall(segment, args), AttrVec::new()))
826826
} else {
827827
// Field access `expr.f`
828-
if let Some(args) = segment.args {
829-
self.struct_span_err(
830-
args.span(),
831-
"field expressions may not have generic arguments",
832-
)
833-
.emit();
834-
}
835-
836828
let span = lo.to(self.prev_span);
837-
Ok(self.mk_expr(span, ExprKind::Field(self_arg, segment.ident), AttrVec::new()))
829+
Ok(self.mk_expr(
830+
span,
831+
ExprKind::Field(self_arg, segment.ident, segment.args.map(|args| args.span())),
832+
AttrVec::new(),
833+
))
838834
}
839835
}
840836

‎src/librustc_passes/liveness.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -984,7 +984,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
984984
self.access_path(expr.hir_id, path, succ, ACC_READ | ACC_USE)
985985
}
986986

987-
hir::ExprKind::Field(ref e, _) => self.propagate_through_expr(&e, succ),
987+
hir::ExprKind::Field(ref e, ..) => self.propagate_through_expr(&e, succ),
988988

989989
hir::ExprKind::Closure(..) => {
990990
debug!(
@@ -1254,7 +1254,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
12541254

12551255
match expr.kind {
12561256
hir::ExprKind::Path(_) => succ,
1257-
hir::ExprKind::Field(ref e, _) => self.propagate_through_expr(&e, succ),
1257+
hir::ExprKind::Field(ref e, ..) => self.propagate_through_expr(&e, succ),
12581258
_ => self.propagate_through_expr(expr, succ),
12591259
}
12601260
}

‎src/librustc_passes/region.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -653,7 +653,7 @@ fn resolve_local<'tcx>(
653653
match expr.kind {
654654
hir::ExprKind::AddrOf(_, _, ref subexpr)
655655
| hir::ExprKind::Unary(hir::UnOp::UnDeref, ref subexpr)
656-
| hir::ExprKind::Field(ref subexpr, _)
656+
| hir::ExprKind::Field(ref subexpr, ..)
657657
| hir::ExprKind::Index(ref subexpr, _) => {
658658
expr = &subexpr;
659659
}

‎src/librustc_resolve/late.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -2004,7 +2004,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
20042004
ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
20052005

20062006
// Equivalent to `visit::walk_expr` + passing some context to children.
2007-
ExprKind::Field(ref subexpression, _) => {
2007+
ExprKind::Field(ref subexpression, ..) => {
20082008
self.resolve_expr(subexpression, Some(expr));
20092009
}
20102010
ExprKind::MethodCall(ref segment, ref arguments) => {
@@ -2055,7 +2055,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
20552055

20562056
fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &'ast Expr) {
20572057
match expr.kind {
2058-
ExprKind::Field(_, ident) => {
2058+
ExprKind::Field(_, ident, _) => {
20592059
// FIXME(#6890): Even though you can't treat a method like a
20602060
// field, we need to add any trait methods we find that match
20612061
// the field name so that we can do some nice error reporting

‎src/librustc_resolve/late/diagnostics.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -415,7 +415,7 @@ impl<'a> LateResolutionVisitor<'a, '_, '_> {
415415
let is_expected = &|res| source.is_expected(res);
416416

417417
let path_sep = |err: &mut DiagnosticBuilder<'_>, expr: &Expr| match expr.kind {
418-
ExprKind::Field(_, ident) => {
418+
ExprKind::Field(_, ident, _) => {
419419
err.span_suggestion(
420420
expr.span,
421421
"use the path separator to refer to an item",

‎src/librustc_save_analysis/dump_visitor.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -1431,7 +1431,7 @@ impl<'l, 'tcx> Visitor<'l> for DumpVisitor<'l, 'tcx> {
14311431
self.process_struct_lit(ex, path, fields, adt.variant_of_res(res), base)
14321432
}
14331433
ast::ExprKind::MethodCall(ref seg, ref args) => self.process_method_call(ex, seg, args),
1434-
ast::ExprKind::Field(ref sub_ex, _) => {
1434+
ast::ExprKind::Field(ref sub_ex, ..) => {
14351435
self.visit_expr(&sub_ex);
14361436

14371437
if let Some(field_data) = self.save_ctxt.get_expr_data(ex) {

‎src/librustc_save_analysis/lib.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -514,7 +514,7 @@ impl<'l, 'tcx> SaveContext<'l, 'tcx> {
514514
return None;
515515
}
516516
match expr.kind {
517-
ast::ExprKind::Field(ref sub_ex, ident) => {
517+
ast::ExprKind::Field(ref sub_ex, ident, _) => {
518518
let sub_ex_hir_id = self.tcx.hir().node_to_hir_id(sub_ex.id);
519519
let hir_node = match self.tcx.hir().find(sub_ex_hir_id) {
520520
Some(Node::Expr(expr)) => expr,

‎src/librustc_typeck/check/expr.rs

+23-2
Original file line numberDiff line numberDiff line change
@@ -277,7 +277,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
277277
ExprKind::Struct(ref qpath, fields, ref base_expr) => {
278278
self.check_expr_struct(expr, expected, qpath, fields, base_expr)
279279
}
280-
ExprKind::Field(ref base, field) => self.check_field(expr, needs, &base, field),
280+
ExprKind::Field(ref base, field, _) => self.check_field(expr, needs, &base, field),
281281
ExprKind::Index(ref base, ref idx) => self.check_expr_index(base, idx, needs, expr),
282282
ExprKind::Yield(ref value, ref src) => self.check_expr_yield(value, expr, src),
283283
hir::ExprKind::Err => tcx.types.err,
@@ -1440,6 +1440,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
14401440
display
14411441
}
14421442

1443+
fn complain_about_invalid_type_params(&self, args: Option<Span>) {
1444+
if let Some(args) = args {
1445+
self.tcx
1446+
.sess
1447+
.struct_span_err(args, "field expressions may not have generic arguments")
1448+
.emit();
1449+
}
1450+
}
1451+
14431452
// Check field access expressions
14441453
fn check_field(
14451454
&self,
@@ -1452,6 +1461,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
14521461
let expr_t = self.structurally_resolved_type(base.span, expr_t);
14531462
let mut private_candidate = None;
14541463
let mut autoderef = self.autoderef(expr.span, expr_t);
1464+
let invalid_args = match &expr.kind {
1465+
ExprKind::Field(_, _, Some(args)) => Some(*args),
1466+
_ => None,
1467+
};
14551468
while let Some((base_t, _)) = autoderef.next() {
14561469
match base_t.kind {
14571470
ty::Adt(base_def, substs) if !base_def.is_enum() => {
@@ -1471,6 +1484,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
14711484
autoderef.finalize(self);
14721485

14731486
self.tcx.check_stability(field.did, Some(expr.hir_id), expr.span);
1487+
self.complain_about_invalid_type_params(invalid_args);
14741488
return field_ty;
14751489
}
14761490
private_candidate = Some((base_def.did, field_ty));
@@ -1486,6 +1500,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
14861500
autoderef.finalize(self);
14871501

14881502
self.write_field_index(expr.hir_id, index);
1503+
self.complain_about_invalid_type_params(invalid_args);
14891504
return field_ty.expect_ty();
14901505
}
14911506
}
@@ -1501,8 +1516,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
15011516
return field_ty;
15021517
}
15031518

1519+
let method_exists = self.method_exists(field, expr_t, expr.hir_id, true);
1520+
if let (false, ExprKind::Field(_, _, Some(_))) = (method_exists, &expr.kind) {
1521+
// Only complain about incorrect field expressions with type parameters like
1522+
// `foo.bar::<baz>` when `bar` isn't a valid method.
1523+
self.complain_about_invalid_type_params(invalid_args);
1524+
}
15041525
if field.name == kw::Invalid {
1505-
} else if self.method_exists(field, expr_t, expr.hir_id, true) {
1526+
} else if method_exists {
15061527
self.ban_take_value_of_method(expr, expr_t, field);
15071528
} else if !expr_t.is_primitive_ty() {
15081529
self.ban_nonexisting_field(field, base, expr, expr_t);

‎src/librustc_typeck/check/method/confirm.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -423,7 +423,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
423423

424424
loop {
425425
match exprs.last().unwrap().kind {
426-
hir::ExprKind::Field(ref expr, _)
426+
hir::ExprKind::Field(ref expr, ..)
427427
| hir::ExprKind::Index(ref expr, _)
428428
| hir::ExprKind::Unary(hir::UnOp::UnDeref, ref expr) => exprs.push(&expr),
429429
_ => break,

‎src/librustc_typeck/expr_use_visitor.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -168,7 +168,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
168168
self.select_from_expr(base);
169169
}
170170

171-
hir::ExprKind::Field(ref base, _) => {
171+
hir::ExprKind::Field(ref base, ..) => {
172172
// base.f
173173
self.select_from_expr(base);
174174
}

‎src/librustc_typeck/mem_categorization.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -354,7 +354,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
354354
}
355355
}
356356

357-
hir::ExprKind::Field(ref base, _) => {
357+
hir::ExprKind::Field(ref base, ..) => {
358358
let base = self.cat_expr(&base)?;
359359
debug!("cat_expr(cat_field): id={} expr={:?} base={:?}", expr.hir_id, expr, base);
360360
Ok(self.cat_projection(expr, base, expr_ty))

‎src/libsyntax/ast.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -1224,7 +1224,8 @@ pub enum ExprKind {
12241224
/// E.g., `a += 1`.
12251225
AssignOp(BinOp, P<Expr>, P<Expr>),
12261226
/// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct field.
1227-
Field(P<Expr>, Ident),
1227+
/// The optional `Span` points at an *invalid* type parameter in the field expression.
1228+
Field(P<Expr>, Ident, Option<Span>),
12281229
/// An indexing operation (e.g., `foo[2]`).
12291230
Index(P<Expr>, P<Expr>),
12301231
/// A range (e.g., `1..2`, `1..`, `..2`, `1..=2`, `..=2`).

‎src/libsyntax/mut_visit.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -1187,7 +1187,7 @@ pub fn noop_visit_expr<T: MutVisitor>(Expr { kind, id, span, attrs }: &mut Expr,
11871187
vis.visit_expr(el);
11881188
vis.visit_expr(er);
11891189
}
1190-
ExprKind::Field(el, ident) => {
1190+
ExprKind::Field(el, ident, _) => {
11911191
vis.visit_expr(el);
11921192
vis.visit_ident(ident);
11931193
}

‎src/libsyntax/util/parser.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -388,7 +388,7 @@ pub fn contains_exterior_struct_lit(value: &ast::Expr) -> bool {
388388
| ast::ExprKind::Unary(_, ref x)
389389
| ast::ExprKind::Cast(ref x, _)
390390
| ast::ExprKind::Type(ref x, _)
391-
| ast::ExprKind::Field(ref x, _)
391+
| ast::ExprKind::Field(ref x, ..)
392392
| ast::ExprKind::Index(ref x, _) => {
393393
// &X { y: 1 }, X { y: 1 }.y
394394
contains_exterior_struct_lit(&x)

‎src/libsyntax/visit.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -773,7 +773,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
773773
visitor.visit_expr(left_expression);
774774
visitor.visit_expr(right_expression);
775775
}
776-
ExprKind::Field(ref subexpression, ident) => {
776+
ExprKind::Field(ref subexpression, ident, _) => {
777777
visitor.visit_expr(subexpression);
778778
visitor.visit_ident(ident);
779779
}

‎src/test/ui-fulldeps/pprust-expr-roundtrip.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -132,7 +132,7 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
132132
iter_exprs(depth - 1, &mut |e| g(ExprKind::Assign(make_x(), e, DUMMY_SP)));
133133
},
134134
13 => {
135-
iter_exprs(depth - 1, &mut |e| g(ExprKind::Field(e, Ident::from_str("f"))));
135+
iter_exprs(depth - 1, &mut |e| g(ExprKind::Field(e, Ident::from_str("f"), None)));
136136
},
137137
14 => {
138138
iter_exprs(depth - 1, &mut |e| g(ExprKind::Range(

‎src/test/ui/suggestions/method-missing-parentheses.rs

-1
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,4 @@
11
fn main() {
22
let _ = vec![].into_iter().collect::<usize>;
33
//~^ ERROR attempted to take value of method `collect` on type `std::vec::IntoIter<_>`
4-
//~| ERROR field expressions may not have generic arguments
54
}

‎src/test/ui/suggestions/method-missing-parentheses.stderr

+1-7
Original file line numberDiff line numberDiff line change
@@ -1,9 +1,3 @@
1-
error: field expressions may not have generic arguments
2-
--> $DIR/method-missing-parentheses.rs:2:41
3-
|
4-
LL | let _ = vec![].into_iter().collect::<usize>;
5-
| ^^^^^^^
6-
71
error[E0615]: attempted to take value of method `collect` on type `std::vec::IntoIter<_>`
82
--> $DIR/method-missing-parentheses.rs:2:32
93
|
@@ -12,6 +6,6 @@ LL | let _ = vec![].into_iter().collect::<usize>;
126
| |
137
| help: use parentheses to call the method: `collect::<usize>()`
148

15-
error: aborting due to 2 previous errors
9+
error: aborting due to previous error
1610

1711
For more information about this error, try `rustc --explain E0615`.

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