From 409c14197372495b26fa8ee9f4b812492a7fb75a Mon Sep 17 00:00:00 2001 From: David Wood Date: Thu, 10 Sep 2020 12:32:45 +0100 Subject: [PATCH] typeck/pat: inaccessible private fields This commit adjusts the missing field diagnostic logic for struct patterns in typeck to improve the diagnostic when the missing fields are inaccessible. Signed-off-by: David Wood --- compiler/rustc_typeck/src/check/pat.rs | 90 ++++++++++++++++++++++--- src/test/ui/issues/issue-76077-1.fixed | 18 +++++ src/test/ui/issues/issue-76077-1.rs | 18 +++++ src/test/ui/issues/issue-76077-1.stderr | 24 +++++++ 4 files changed, 141 insertions(+), 9 deletions(-) create mode 100644 src/test/ui/issues/issue-76077-1.fixed create mode 100644 src/test/ui/issues/issue-76077-1.rs create mode 100644 src/test/ui/issues/issue-76077-1.stderr diff --git a/compiler/rustc_typeck/src/check/pat.rs b/compiler/rustc_typeck/src/check/pat.rs index f06929aa98f..1896155e327 100644 --- a/compiler/rustc_typeck/src/check/pat.rs +++ b/compiler/rustc_typeck/src/check/pat.rs @@ -1078,8 +1078,8 @@ fn check_struct_pat_fields( let mut unmentioned_fields = variant .fields .iter() - .map(|field| field.ident.normalize_to_macros_2_0()) - .filter(|ident| !used_fields.contains_key(&ident)) + .map(|field| (field, field.ident.normalize_to_macros_2_0())) + .filter(|(_, ident)| !used_fields.contains_key(&ident)) .collect::>(); let inexistent_fields_err = if !(inexistent_fields.is_empty() || variant.is_recovered()) { @@ -1110,7 +1110,19 @@ fn check_struct_pat_fields( tcx.sess.struct_span_err(pat.span, "`..` cannot be used in union patterns").emit(); } } else if !etc && !unmentioned_fields.is_empty() { - unmentioned_err = Some(self.error_unmentioned_fields(pat, &unmentioned_fields)); + let no_accessible_unmentioned_fields = unmentioned_fields + .iter() + .filter(|(field, _)| { + field.vis.is_accessible_from(tcx.parent_module(pat.hir_id).to_def_id(), tcx) + }) + .next() + .is_none(); + + if no_accessible_unmentioned_fields { + unmentioned_err = Some(self.error_no_accessible_fields(pat, &fields)); + } else { + unmentioned_err = Some(self.error_unmentioned_fields(pat, &unmentioned_fields)); + } } match (inexistent_fields_err, unmentioned_err) { (Some(mut i), Some(mut u)) => { @@ -1173,7 +1185,7 @@ fn error_inexistent_fields( &self, kind_name: &str, inexistent_fields: &[Ident], - unmentioned_fields: &mut Vec, + unmentioned_fields: &mut Vec<(&ty::FieldDef, Ident)>, variant: &ty::VariantDef, ) -> DiagnosticBuilder<'tcx> { let tcx = self.tcx; @@ -1215,7 +1227,7 @@ fn error_inexistent_fields( ), ); if plural == "" { - let input = unmentioned_fields.iter().map(|field| &field.name); + let input = unmentioned_fields.iter().map(|(_, field)| &field.name); let suggested_name = find_best_match_for_name(input, ident.name, None); if let Some(suggested_name) = suggested_name { err.span_suggestion( @@ -1232,7 +1244,7 @@ fn error_inexistent_fields( // `smart_resolve_context_dependent_help`. if suggested_name.to_ident_string().parse::().is_err() { // We don't want to throw `E0027` in case we have thrown `E0026` for them. - unmentioned_fields.retain(|&x| x.name != suggested_name); + unmentioned_fields.retain(|&(_, x)| x.name != suggested_name); } } } @@ -1300,17 +1312,77 @@ fn error_tuple_variant_as_struct_pat( None } + /// Returns a diagnostic reporting a struct pattern which is missing an `..` due to + /// inaccessible fields. + /// + /// ```ignore (diagnostic) + /// error: pattern requires `..` due to inaccessible fields + /// --> src/main.rs:10:9 + /// | + /// LL | let foo::Foo {} = foo::Foo::default(); + /// | ^^^^^^^^^^^ + /// | + /// help: add a `..` + /// | + /// LL | let foo::Foo { .. } = foo::Foo::default(); + /// | ^^^^^^ + /// ``` + fn error_no_accessible_fields( + &self, + pat: &Pat<'_>, + fields: &'tcx [hir::FieldPat<'tcx>], + ) -> DiagnosticBuilder<'tcx> { + let mut err = self + .tcx + .sess + .struct_span_err(pat.span, "pattern requires `..` due to inaccessible fields"); + + if let Some(field) = fields.last() { + err.span_suggestion_verbose( + field.span.shrink_to_hi(), + "ignore the inaccessible and unused fields", + ", ..".to_string(), + Applicability::MachineApplicable, + ); + } else { + let qpath_span = if let PatKind::Struct(qpath, ..) = &pat.kind { + qpath.span() + } else { + bug!("`error_no_accessible_fields` called on non-struct pattern"); + }; + + // Shrink the span to exclude the `foo:Foo` in `foo::Foo { }`. + let span = pat.span.with_lo(qpath_span.shrink_to_hi().hi()); + err.span_suggestion_verbose( + span, + "ignore the inaccessible and unused fields", + " { .. }".to_string(), + Applicability::MachineApplicable, + ); + } + err + } + + /// Returns a diagnostic reporting a struct pattern which does not mention some fields. + /// + /// ```ignore (diagnostic) + /// error[E0027]: pattern does not mention field `you_cant_use_this_field` + /// --> src/main.rs:15:9 + /// | + /// LL | let foo::Foo {} = foo::Foo::new(); + /// | ^^^^^^^^^^^ missing field `you_cant_use_this_field` + /// ``` fn error_unmentioned_fields( &self, pat: &Pat<'_>, - unmentioned_fields: &[Ident], + unmentioned_fields: &[(&ty::FieldDef, Ident)], ) -> DiagnosticBuilder<'tcx> { let field_names = if unmentioned_fields.len() == 1 { - format!("field `{}`", unmentioned_fields[0]) + format!("field `{}`", unmentioned_fields[0].1) } else { let fields = unmentioned_fields .iter() - .map(|name| format!("`{}`", name)) + .map(|(_, name)| format!("`{}`", name)) .collect::>() .join(", "); format!("fields {}", fields) diff --git a/src/test/ui/issues/issue-76077-1.fixed b/src/test/ui/issues/issue-76077-1.fixed new file mode 100644 index 00000000000..8103a7ca47d --- /dev/null +++ b/src/test/ui/issues/issue-76077-1.fixed @@ -0,0 +1,18 @@ +// run-rustfix +#![allow(dead_code, unused_variables)] + +pub mod foo { + #[derive(Default)] + pub struct Foo { invisible: bool, } + + #[derive(Default)] + pub struct Bar { pub visible: bool, invisible: bool, } +} + +fn main() { + let foo::Foo { .. } = foo::Foo::default(); + //~^ ERROR pattern requires `..` due to inaccessible fields + + let foo::Bar { visible, .. } = foo::Bar::default(); + //~^ ERROR pattern requires `..` due to inaccessible fields +} diff --git a/src/test/ui/issues/issue-76077-1.rs b/src/test/ui/issues/issue-76077-1.rs new file mode 100644 index 00000000000..730332853c1 --- /dev/null +++ b/src/test/ui/issues/issue-76077-1.rs @@ -0,0 +1,18 @@ +// run-rustfix +#![allow(dead_code, unused_variables)] + +pub mod foo { + #[derive(Default)] + pub struct Foo { invisible: bool, } + + #[derive(Default)] + pub struct Bar { pub visible: bool, invisible: bool, } +} + +fn main() { + let foo::Foo {} = foo::Foo::default(); + //~^ ERROR pattern requires `..` due to inaccessible fields + + let foo::Bar { visible } = foo::Bar::default(); + //~^ ERROR pattern requires `..` due to inaccessible fields +} diff --git a/src/test/ui/issues/issue-76077-1.stderr b/src/test/ui/issues/issue-76077-1.stderr new file mode 100644 index 00000000000..4557595529f --- /dev/null +++ b/src/test/ui/issues/issue-76077-1.stderr @@ -0,0 +1,24 @@ +error: pattern requires `..` due to inaccessible fields + --> $DIR/issue-76077-1.rs:13:9 + | +LL | let foo::Foo {} = foo::Foo::default(); + | ^^^^^^^^^^^ + | +help: ignore the inaccessible and unused fields + | +LL | let foo::Foo { .. } = foo::Foo::default(); + | ^^^^^^ + +error: pattern requires `..` due to inaccessible fields + --> $DIR/issue-76077-1.rs:16:9 + | +LL | let foo::Bar { visible } = foo::Bar::default(); + | ^^^^^^^^^^^^^^^^^^^^ + | +help: ignore the inaccessible and unused fields + | +LL | let foo::Bar { visible, .. } = foo::Bar::default(); + | ^^^^ + +error: aborting due to 2 previous errors + -- 2.44.0