Rollup merge of #101357 - compiler-errors:variant-sugg-tweak, r=oli-obk

Include enum path in variant suggestion

(except for `Result` and `Option`, which we should have via the prelude)

Fixes #101356

Author: GuillaumeGomez

compiler/rustc_middle/src/thir.rs

@@ -23,7 +23,7 @@ use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, AdtDef, Ty, UpvarSubsts};
 use rustc_middle::ty::{CanonicalUserType, CanonicalUserTypeAnnotation};
 use rustc_span::def_id::LocalDefId;
-use rustc_span::{Span, Symbol, DUMMY_SP};
+use rustc_span::{sym, Span, Symbol, DUMMY_SP};
 use rustc_target::abi::VariantIdx;
 use rustc_target::asm::InlineAsmRegOrRegClass;
 use std::fmt;
@@ -695,17 +695,32 @@ impl<'tcx> fmt::Display for Pat<'tcx> {
                 Ok(())
             }
             PatKind::Variant { ref subpatterns, .. } | PatKind::Leaf { ref subpatterns } => {
-                let variant = match self.kind {
-                    PatKind::Variant { adt_def, variant_index, .. } => {
-                        Some(adt_def.variant(variant_index))
-                    }
-                    _ => self.ty.ty_adt_def().and_then(|adt| {
-                        if !adt.is_enum() { Some(adt.non_enum_variant()) } else { None }
+                let variant_and_name = match self.kind {
+                    PatKind::Variant { adt_def, variant_index, .. } => ty::tls::with(|tcx| {
+                        let variant = adt_def.variant(variant_index);
+                        let adt_did = adt_def.did();
+                        let name = if tcx.get_diagnostic_item(sym::Option) == Some(adt_did)
+                            || tcx.get_diagnostic_item(sym::Result) == Some(adt_did)
+                        {
+                            variant.name.to_string()
+                        } else {
+                            format!("{}::{}", tcx.def_path_str(adt_def.did()), variant.name)
+                        };
+                        Some((variant, name))
+                    }),
+                    _ => self.ty.ty_adt_def().and_then(|adt_def| {
+                        if !adt_def.is_enum() {
+                            ty::tls::with(|tcx| {
+                                Some((adt_def.non_enum_variant(), tcx.def_path_str(adt_def.did())))
+                            })
+                        } else {
+                            None
+                        }
                     }),
                 };
 
-                if let Some(variant) = variant {
-                    write!(f, "{}", variant.name)?;
+                if let Some((variant, name)) = &variant_and_name {
+                    write!(f, "{}", name)?;
 
                     // Only for Adt we can have `S {...}`,
                     // which we handle separately here.
@@ -730,8 +745,9 @@ impl<'tcx> fmt::Display for Pat<'tcx> {
                     }
                 }
 
-                let num_fields = variant.map_or(subpatterns.len(), |v| v.fields.len());
-                if num_fields != 0 || variant.is_none() {
+                let num_fields =
+                    variant_and_name.as_ref().map_or(subpatterns.len(), |(v, _)| v.fields.len());
+                if num_fields != 0 || variant_and_name.is_none() {
                     write!(f, "(")?;
                     for i in 0..num_fields {
                         write!(f, "{}", start_or_comma())?;

compiler/rustc_mir_build/src/thir/pattern/usefulness.rs

@@ -754,8 +754,8 @@ fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>(
     hir_id: HirId,
     witnesses: Vec<DeconstructedPat<'p, 'tcx>>,
 ) {
-    let joined_patterns = joined_uncovered_patterns(cx, &witnesses);
     cx.tcx.struct_span_lint_hir(NON_EXHAUSTIVE_OMITTED_PATTERNS, hir_id, sp, |build| {
+        let joined_patterns = joined_uncovered_patterns(cx, &witnesses);
         let mut lint = build.build("some variants are not matched explicitly");
         lint.span_label(sp, pattern_not_covered_label(&witnesses, &joined_patterns));
         lint.help(

src/test/ui/closures/2229_closure_analysis/match/non-exhaustive-match.rs

@@ -24,7 +24,7 @@ fn main() {
     let _a = || { match l1 { L1::A => (), L1::B => () } };
     // (except if the match is already non-exhaustive)
     let _b = || { match l1 { L1::A => () } };
-    //~^ ERROR: non-exhaustive patterns: `B` not covered [E0004]
+    //~^ ERROR: non-exhaustive patterns: `L1::B` not covered [E0004]
 
     // l2 should not be captured as it is a non-exhaustive SingleVariant
     // defined in this crate

src/test/ui/closures/2229_closure_analysis/match/non-exhaustive-match.stderr

@@ -1,8 +1,8 @@
-error[E0004]: non-exhaustive patterns: `B` not covered
+error[E0004]: non-exhaustive patterns: `L1::B` not covered
   --> $DIR/non-exhaustive-match.rs:26:25
    |
 LL |     let _b = || { match l1 { L1::A => () } };
-   |                         ^^ pattern `B` not covered
+   |                         ^^ pattern `L1::B` not covered
    |
 note: `L1` defined here
   --> $DIR/non-exhaustive-match.rs:12:14
@@ -12,8 +12,8 @@ LL | enum L1 { A, B }
    = note: the matched value is of type `L1`
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
    |
-LL |     let _b = || { match l1 { L1::A => (), B => todo!() } };
-   |                                         ++++++++++++++
+LL |     let _b = || { match l1 { L1::A => (), L1::B => todo!() } };
+   |                                         ++++++++++++++++++
 
 error[E0004]: non-exhaustive patterns: type `E1` is non-empty
   --> $DIR/non-exhaustive-match.rs:37:25

src/test/ui/empty/empty-never-array.rs

@@ -8,7 +8,7 @@ enum Helper<T, U> {
 
 fn transmute<T, U>(t: T) -> U {
     let Helper::U(u) = Helper::T(t, []);
-    //~^ ERROR refutable pattern in local binding: `T(_, _)` not covered
+    //~^ ERROR refutable pattern in local binding: `Helper::T(_, _)` not covered
     u
 }
 

src/test/ui/empty/empty-never-array.stderr

@@ -1,8 +1,8 @@
-error[E0005]: refutable pattern in local binding: `T(_, _)` not covered
+error[E0005]: refutable pattern in local binding: `Helper::T(_, _)` not covered
   --> $DIR/empty-never-array.rs:10:9
    |
 LL |     let Helper::U(u) = Helper::T(t, []);
-   |         ^^^^^^^^^^^^ pattern `T(_, _)` not covered
+   |         ^^^^^^^^^^^^ pattern `Helper::T(_, _)` not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html

src/test/ui/error-codes/E0004.stderr

@@ -1,8 +1,8 @@
-error[E0004]: non-exhaustive patterns: `HastaLaVistaBaby` not covered
+error[E0004]: non-exhaustive patterns: `Terminator::HastaLaVistaBaby` not covered
   --> $DIR/E0004.rs:9:11
    |
 LL |     match x {
-   |           ^ pattern `HastaLaVistaBaby` not covered
+   |           ^ pattern `Terminator::HastaLaVistaBaby` not covered
    |
 note: `Terminator` defined here
   --> $DIR/E0004.rs:2:5
@@ -15,7 +15,7 @@ LL |     HastaLaVistaBaby,
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
    |
 LL ~         Terminator::TalkToMyHand => {}
-LL +         HastaLaVistaBaby => todo!()
+LL +         Terminator::HastaLaVistaBaby => todo!()
    |
 
 error: aborting due to previous error

src/test/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs

@@ -21,7 +21,7 @@ fn main() {
         Foo::A => {}
         Foo::B => {}
     }
-    //~^^^^ ERROR non-exhaustive patterns: `C` not covered
+    //~^^^^ ERROR non-exhaustive patterns: `Foo::C` not covered
 
     match Foo::A {
         Foo::A => {}

src/test/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr

@@ -99,11 +99,11 @@ LL |         #[warn(non_exhaustive_omitted_patterns)]
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0004]: non-exhaustive patterns: `C` not covered
+error[E0004]: non-exhaustive patterns: `Foo::C` not covered
   --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:20:11
    |
 LL |     match Foo::A {
-   |           ^^^^^^ pattern `C` not covered
+   |           ^^^^^^ pattern `Foo::C` not covered
    |
 note: `Foo` defined here
   --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:12:15
@@ -116,7 +116,7 @@ LL |         A, B, C,
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
    |
 LL ~         Foo::B => {}
-LL +         C => todo!()
+LL +         Foo::C => todo!()
    |
 
 error: aborting due to previous error; 10 warnings emitted

src/test/ui/issue-94866.stderr

@@ -1,8 +1,8 @@
-error[E0004]: non-exhaustive patterns: `B` not covered
+error[E0004]: non-exhaustive patterns: `Enum::B` not covered
   --> $DIR/issue-94866.rs:10:11
    |
 LL |     match Enum::A {
-   |           ^^^^^^^ pattern `B` not covered
+   |           ^^^^^^^ pattern `Enum::B` not covered
    |
 note: `Enum` defined here
   --> $DIR/issue-94866.rs:7:16
@@ -13,7 +13,7 @@ LL | enum Enum { A, B }
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
    |
 LL ~     Enum::A => m!(),
-LL +     B => todo!()
+LL +     Enum::B => todo!()
    |
 
 error: aborting due to previous error