From 8f705e2425ff459566cd1da0f2c79060fdad9091 Mon Sep 17 00:00:00 2001 From: Sarthak Singh Date: Wed, 9 Nov 2022 20:39:28 +0530 Subject: [PATCH] Keep track of the start of the argument block of a closure --- compiler/rustc_ast/src/ast.rs | 4 ++- compiler/rustc_ast/src/mut_visit.rs | 1 + compiler/rustc_ast/src/visit.rs | 1 + compiler/rustc_ast_lowering/src/expr.rs | 8 +++++ .../rustc_ast_pretty/src/pprust/state/expr.rs | 1 + compiler/rustc_expand/src/build.rs | 3 ++ compiler/rustc_hir/src/hir.rs | 3 ++ compiler/rustc_hir/src/intravisit.rs | 1 + compiler/rustc_hir_pretty/src/lib.rs | 1 + compiler/rustc_hir_typeck/src/closure.rs | 10 +++--- compiler/rustc_middle/src/hir/map/mod.rs | 2 +- compiler/rustc_parse/src/parser/expr.rs | 10 ++++-- .../src/traits/error_reporting/mod.rs | 35 ++++++++----------- src/test/ui-fulldeps/pprust-expr-roundtrip.rs | 1 + src/tools/rustfmt/src/closures.rs | 1 + 15 files changed, 53 insertions(+), 29 deletions(-) diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs index 54bd25d647130..d30cbdca29db3 100644 --- a/compiler/rustc_ast/src/ast.rs +++ b/compiler/rustc_ast/src/ast.rs @@ -1280,8 +1280,10 @@ pub struct Closure { pub movability: Movability, pub fn_decl: P, pub body: P, - /// The span of the argument block `|...|`. + /// The span of the declaration block: 'move |...| -> ...' pub fn_decl_span: Span, + /// The span of the argument block `|...|` + pub fn_arg_span: Span, } /// Limit types of a range (inclusive or exclusive) diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs index 4e1dcb2842f67..7e1aebe1920c9 100644 --- a/compiler/rustc_ast/src/mut_visit.rs +++ b/compiler/rustc_ast/src/mut_visit.rs @@ -1371,6 +1371,7 @@ pub fn noop_visit_expr( fn_decl, body, fn_decl_span, + fn_arg_span: _, }) => { vis.visit_closure_binder(binder); vis.visit_asyncness(asyncness); diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs index 5c69e53521275..08166c7327f37 100644 --- a/compiler/rustc_ast/src/visit.rs +++ b/compiler/rustc_ast/src/visit.rs @@ -840,6 +840,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) { fn_decl, body, fn_decl_span: _, + fn_arg_span: _, }) => { visitor.visit_fn(FnKind::Closure(binder, fn_decl, body), expression.span, expression.id) } diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs index a00100ee0a845..4385552f2cc2e 100644 --- a/compiler/rustc_ast_lowering/src/expr.rs +++ b/compiler/rustc_ast_lowering/src/expr.rs @@ -176,6 +176,7 @@ impl<'hir> LoweringContext<'_, 'hir> { fn_decl, body, fn_decl_span, + fn_arg_span, }) => { if let Async::Yes { closure_id, .. } = asyncness { self.lower_expr_async_closure( @@ -186,6 +187,7 @@ impl<'hir> LoweringContext<'_, 'hir> { fn_decl, body, *fn_decl_span, + *fn_arg_span, ) } else { self.lower_expr_closure( @@ -196,6 +198,7 @@ impl<'hir> LoweringContext<'_, 'hir> { fn_decl, body, *fn_decl_span, + *fn_arg_span, ) } } @@ -639,6 +642,7 @@ impl<'hir> LoweringContext<'_, 'hir> { fn_decl, body, fn_decl_span: self.lower_span(span), + fn_arg_span: None, movability: Some(hir::Movability::Static), }); @@ -887,6 +891,7 @@ impl<'hir> LoweringContext<'_, 'hir> { decl: &FnDecl, body: &Expr, fn_decl_span: Span, + fn_arg_span: Span, ) -> hir::ExprKind<'hir> { let (binder_clause, generic_params) = self.lower_closure_binder(binder); @@ -917,6 +922,7 @@ impl<'hir> LoweringContext<'_, 'hir> { fn_decl, body: body_id, fn_decl_span: self.lower_span(fn_decl_span), + fn_arg_span: Some(self.lower_span(fn_arg_span)), movability: generator_option, }); @@ -973,6 +979,7 @@ impl<'hir> LoweringContext<'_, 'hir> { decl: &FnDecl, body: &Expr, fn_decl_span: Span, + fn_arg_span: Span, ) -> hir::ExprKind<'hir> { if let &ClosureBinder::For { span, .. } = binder { self.tcx.sess.emit_err(NotSupportedForLifetimeBinderAsyncClosure { span }); @@ -1027,6 +1034,7 @@ impl<'hir> LoweringContext<'_, 'hir> { fn_decl, body, fn_decl_span: self.lower_span(fn_decl_span), + fn_arg_span: Some(self.lower_span(fn_arg_span)), movability: None, }); hir::ExprKind::Closure(c) diff --git a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs index 1da40d2302e12..8d905322e1dfb 100644 --- a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs +++ b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs @@ -409,6 +409,7 @@ impl<'a> State<'a> { ref fn_decl, ref body, fn_decl_span: _, + fn_arg_span: _, }) => { self.print_closure_binder(binder); self.print_movability(movability); diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs index e17cba1478ab6..40f5d739f674f 100644 --- a/compiler/rustc_expand/src/build.rs +++ b/compiler/rustc_expand/src/build.rs @@ -539,6 +539,9 @@ impl<'a> ExtCtxt<'a> { fn_decl, body, fn_decl_span: span, + // FIXME(SarthakSingh31): This points to the start of the declaration block and + // not the span of the argument block. + fn_arg_span: span, })), ) } diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs index 473a04f33a9ad..34836ab73302c 100644 --- a/compiler/rustc_hir/src/hir.rs +++ b/compiler/rustc_hir/src/hir.rs @@ -928,7 +928,10 @@ pub struct Closure<'hir> { pub bound_generic_params: &'hir [GenericParam<'hir>], pub fn_decl: &'hir FnDecl<'hir>, pub body: BodyId, + /// The span of the declaration block: 'move |...| -> ...' pub fn_decl_span: Span, + /// The span of the argument block `|...|` + pub fn_arg_span: Option, pub movability: Option, } diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs index 48db93fde9d4c..8ced4aa23c066 100644 --- a/compiler/rustc_hir/src/intravisit.rs +++ b/compiler/rustc_hir/src/intravisit.rs @@ -740,6 +740,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) body, capture_clause: _, fn_decl_span: _, + fn_arg_span: _, movability: _, }) => { walk_list!(visitor, visit_generic_param, bound_generic_params); diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs index d70ec94f5b61f..72f3569fc23d5 100644 --- a/compiler/rustc_hir_pretty/src/lib.rs +++ b/compiler/rustc_hir_pretty/src/lib.rs @@ -1480,6 +1480,7 @@ impl<'a> State<'a> { fn_decl, body, fn_decl_span: _, + fn_arg_span: _, movability: _, def_id: _, }) => { diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs index 6cf9e23b40b0e..e75b96da97a9f 100644 --- a/compiler/rustc_hir_typeck/src/closure.rs +++ b/compiler/rustc_hir_typeck/src/closure.rs @@ -457,10 +457,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { .iter() .map(|ty| ArgKind::from_expected_ty(*ty, None)) .collect(); - let (closure_span, found_args) = match self.get_fn_like_arguments(expr_map_node) { - Some((sp, args)) => (Some(sp), args), - None => (None, Vec::new()), - }; + let (closure_span, closure_arg_span, found_args) = + match self.get_fn_like_arguments(expr_map_node) { + Some((sp, arg_sp, args)) => (Some(sp), arg_sp, args), + None => (None, None, Vec::new()), + }; let expected_span = expected_sig.cause_span.unwrap_or_else(|| self.tcx.def_span(expr_def_id)); self.report_arg_count_mismatch( @@ -469,6 +470,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { expected_args, found_args, true, + closure_arg_span, ) .emit(); diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs index d4456adf201a6..68be92ad39836 100644 --- a/compiler/rustc_middle/src/hir/map/mod.rs +++ b/compiler/rustc_middle/src/hir/map/mod.rs @@ -1022,7 +1022,7 @@ impl<'hir> Map<'hir> { .. }) => { // Ensure that the returned span has the item's SyntaxContext. - fn_decl_span.find_ancestor_in_same_ctxt(*span).unwrap_or(*span) + fn_decl_span.find_ancestor_inside(*span).unwrap_or(*span) } _ => self.span_with_body(hir_id), }; diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index dc914f5ea6454..a76f0f46716f7 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -2057,7 +2057,7 @@ impl<'a> Parser<'a> { }; let capture_clause = self.parse_capture_clause()?; - let fn_decl = self.parse_fn_block_decl()?; + let (fn_decl, fn_arg_span) = self.parse_fn_block_decl()?; let decl_hi = self.prev_token.span; let mut body = match fn_decl.output { FnRetTy::Default(_) => { @@ -2098,6 +2098,7 @@ impl<'a> Parser<'a> { fn_decl, body, fn_decl_span: lo.to(decl_hi), + fn_arg_span, })), ); @@ -2126,7 +2127,9 @@ impl<'a> Parser<'a> { } /// Parses the `|arg, arg|` header of a closure. - fn parse_fn_block_decl(&mut self) -> PResult<'a, P> { + fn parse_fn_block_decl(&mut self) -> PResult<'a, (P, Span)> { + let arg_start = self.token.span.lo(); + let inputs = if self.eat(&token::OrOr) { Vec::new() } else { @@ -2142,10 +2145,11 @@ impl<'a> Parser<'a> { self.expect_or()?; args }; + let arg_span = self.prev_token.span.with_lo(arg_start); let output = self.parse_ret_ty(AllowPlus::Yes, RecoverQPath::Yes, RecoverReturnSign::Yes)?; - Ok(P(FnDecl { inputs, output })) + Ok((P(FnDecl { inputs, output }), arg_span)) } /// Parses a parameter in a closure header (e.g., `|arg, arg|`). diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index 59d017545c032..53ce8f368e257 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -70,7 +70,7 @@ pub trait InferCtxtExt<'tcx> { /// returns a span and `ArgKind` information that describes the /// arguments it expects. This can be supplied to /// `report_arg_count_mismatch`. - fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span, Vec)>; + fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span, Option, Vec)>; /// Reports an error when the number of arguments needed by a /// trait match doesn't match the number that the expression @@ -82,6 +82,7 @@ pub trait InferCtxtExt<'tcx> { expected_args: Vec, found_args: Vec, is_closure: bool, + closure_pipe_span: Option, ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed>; /// Checks if the type implements one of `Fn`, `FnMut`, or `FnOnce` @@ -134,15 +135,16 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { /// returns a span and `ArgKind` information that describes the /// arguments it expects. This can be supplied to /// `report_arg_count_mismatch`. - fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span, Vec)> { + fn get_fn_like_arguments(&self, node: Node<'_>) -> Option<(Span, Option, Vec)> { let sm = self.tcx.sess.source_map(); let hir = self.tcx.hir(); Some(match node { Node::Expr(&hir::Expr { - kind: hir::ExprKind::Closure(&hir::Closure { body, fn_decl_span, .. }), + kind: hir::ExprKind::Closure(&hir::Closure { body, fn_decl_span, fn_arg_span, .. }), .. }) => ( fn_decl_span, + fn_arg_span, hir.body(body) .params .iter() @@ -173,6 +175,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { kind: hir::TraitItemKind::Fn(ref sig, _), .. }) => ( sig.span, + None, sig.decl .inputs .iter() @@ -187,7 +190,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { ), Node::Ctor(ref variant_data) => { let span = variant_data.ctor_hir_id().map_or(DUMMY_SP, |id| hir.span(id)); - (span, vec![ArgKind::empty(); variant_data.fields().len()]) + (span, None, vec![ArgKind::empty(); variant_data.fields().len()]) } _ => panic!("non-FnLike node found: {:?}", node), }) @@ -203,6 +206,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { expected_args: Vec, found_args: Vec, is_closure: bool, + closure_arg_span: Option, ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> { let kind = if is_closure { "closure" } else { "function" }; @@ -240,24 +244,13 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { if let Some(found_span) = found_span { err.span_label(found_span, format!("takes {}", found_str)); - // move |_| { ... } - // ^^^^^^^^-- def_span - // - // move |_| { ... } - // ^^^^^-- prefix - let prefix_span = self.tcx.sess.source_map().span_until_non_whitespace(found_span); - // move |_| { ... } - // ^^^-- pipe_span - let pipe_span = - if let Some(span) = found_span.trim_start(prefix_span) { span } else { found_span }; - // Suggest to take and ignore the arguments with expected_args_length `_`s if // found arguments is empty (assume the user just wants to ignore args in this case). // For example, if `expected_args_length` is 2, suggest `|_, _|`. if found_args.is_empty() && is_closure { let underscores = vec!["_"; expected_args.len()].join(", "); err.span_suggestion_verbose( - pipe_span, + closure_arg_span.unwrap_or(found_span), &format!( "consider changing the closure to take and ignore the expected argument{}", pluralize!(expected_args.len()) @@ -1251,13 +1244,14 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { obligation.cause.code(), ) } else { - let (closure_span, found) = found_did + let (closure_span, closure_arg_span, found) = found_did .and_then(|did| { let node = self.tcx.hir().get_if_local(did)?; - let (found_span, found) = self.get_fn_like_arguments(node)?; - Some((Some(found_span), found)) + let (found_span, closure_arg_span, found) = + self.get_fn_like_arguments(node)?; + Some((Some(found_span), closure_arg_span, found)) }) - .unwrap_or((found_span, found)); + .unwrap_or((found_span, None, found)); self.report_arg_count_mismatch( span, @@ -1265,6 +1259,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { expected, found, found_trait_ty.is_closure(), + closure_arg_span, ) } } diff --git a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs index d6dc179da7f98..a93ba87470a9c 100644 --- a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs +++ b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs @@ -126,6 +126,7 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P)) { fn_decl: decl.clone(), body: e, fn_decl_span: DUMMY_SP, + fn_arg_span: DUMMY_SP, }))) }); } diff --git a/src/tools/rustfmt/src/closures.rs b/src/tools/rustfmt/src/closures.rs index 423c3a997f53d..244d4427c5623 100644 --- a/src/tools/rustfmt/src/closures.rs +++ b/src/tools/rustfmt/src/closures.rs @@ -335,6 +335,7 @@ pub(crate) fn rewrite_last_closure( ref fn_decl, ref body, fn_decl_span: _, + fn_arg_span: _, } = **closure; let body = match body.kind { ast::ExprKind::Block(ref block, _)