{"id":2223277,"url":"http://patchwork.ozlabs.org/api/1.2/patches/2223277/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/20260414231905.191063-8-arthur.cohen@embecosm.com/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/1.2/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260414231905.191063-8-arthur.cohen@embecosm.com>","list_archive_url":null,"date":"2026-04-14T23:18:29","name":"[COMMITTED,08/43] gccrs: Improve unit struct matching","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"8517d3ef9042739731a26dfff1e8224b39cc4a54","submitter":{"id":83476,"url":"http://patchwork.ozlabs.org/api/1.2/people/83476/?format=json","name":"Arthur Cohen","email":"arthur.cohen@embecosm.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/20260414231905.191063-8-arthur.cohen@embecosm.com/mbox/","series":[{"id":499900,"url":"http://patchwork.ozlabs.org/api/1.2/series/499900/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=499900","date":"2026-04-14T23:18:24","name":"[COMMITTED,01/43] gccrs: testsuite:Add a testcase for setup_associated_types","version":1,"mbox":"http://patchwork.ozlabs.org/series/499900/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2223277/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2223277/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=embecosm.com 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","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"},"content":"From: Owen Avery \n\nUnit structs weren't *actually* working in match statements -- we don't\ncurrently handle identifier pattern vs path pattern disambiguation.\n\ngcc/rust/ChangeLog:\n\n\t* checks/errors/rust-hir-pattern-analysis.cc\n\t(PlaceInfo::specialize): Handle VariantType::UNIT.\n\t(WitnessPat::to_string): Likewise.\n\t(WitnessMatrix::apply_constructor): Likewise.\n\t* typecheck/rust-hir-type-check-item.cc (TypeCheckItem::visit):\n\tConditionally create VariantType::UNIT variants.\n\t* typecheck/rust-hir-type-check-pattern.cc\n\t(TypeCheckPattern::visit): Fix typo, handle VariantType::UNIT.\n\t* typecheck/rust-tyty-variance-analysis.cc\n\t(GenericTyVisitorCtx::process_type): Handle VariantType::UNIT.\n\t* typecheck/rust-tyty.cc (BaseType::contains_infer): Likewise.\n\t(BaseType::is_concrete): Likewise.\n\t(VariantDef::variant_type_string): Likewise.\n\t(VariantDef::VariantDef): Likewise.\n\t* typecheck/rust-tyty.h (VariantDef::VariantType::UNIT): New\n\tenumerator.\n\ngcc/testsuite/ChangeLog:\n\n\t* rust/compile/match-struct-path.rs: Increase test coverage.\n\nSigned-off-by: Owen Avery \n---\n gcc/rust/checks/errors/rust-hir-pattern-analysis.cc | 8 ++++++--\n gcc/rust/typecheck/rust-hir-type-check-item.cc | 6 ++++--\n gcc/rust/typecheck/rust-hir-type-check-pattern.cc | 6 ++++--\n gcc/rust/typecheck/rust-tyty-variance-analysis.cc | 3 ++-\n gcc/rust/typecheck/rust-tyty.cc | 13 ++++++++++---\n gcc/rust/typecheck/rust-tyty.h | 3 ++-\n gcc/testsuite/rust/compile/match-struct-path.rs | 6 ++++++\n 7 files changed, 34 insertions(+), 11 deletions(-)","diff":"diff --git a/gcc/rust/checks/errors/rust-hir-pattern-analysis.cc b/gcc/rust/checks/errors/rust-hir-pattern-analysis.cc\nindex 431cd9bb891..b2a3e5e9774 100644\n--- a/gcc/rust/checks/errors/rust-hir-pattern-analysis.cc\n+++ b/gcc/rust/checks/errors/rust-hir-pattern-analysis.cc\n@@ -936,7 +936,9 @@ PlaceInfo::specialize (const Constructor &c) const\n \t TyTy::VariantDef *variant\n \t\t= adt->get_variants ().at (c.get_variant_index ());\n \t if (variant->get_variant_type ()\n-\t\t == TyTy::VariantDef::VariantType::NUM)\n+\t\t == TyTy::VariantDef::VariantType::NUM\n+\t\t || variant->get_variant_type ()\n+\t\t == TyTy::VariantDef::VariantType::UNIT)\n \t\treturn {};\n \n \t std::vector new_place_infos;\n@@ -1050,6 +1052,7 @@ WitnessPat::to_string () const\n \n \tswitch (variant->get_variant_type ())\n \t {\n+\t case TyTy::VariantDef::VariantType::UNIT:\n \t case TyTy::VariantDef::VariantType::NUM:\n \t {\n \t return buf;\n@@ -1145,7 +1148,8 @@ WitnessMatrix::apply_constructor (const Constructor &ctor,\n \t TyTy::ADTType *adt = static_cast (ty);\n \t TyTy::VariantDef *variant\n \t = adt->get_variants ().at (ctor.get_variant_index ());\n-\t if (variant->get_variant_type () == TyTy::VariantDef::NUM)\n+\t if (variant->get_variant_type () == TyTy::VariantDef::NUM\n+\t\t|| variant->get_variant_type () == TyTy::VariantDef::UNIT)\n \t arity = 0;\n \t else\n \t arity = variant->get_fields ().size ();\ndiff --git a/gcc/rust/typecheck/rust-hir-type-check-item.cc b/gcc/rust/typecheck/rust-hir-type-check-item.cc\nindex 12ac3986567..f2a40c6c7df 100644\n--- a/gcc/rust/typecheck/rust-hir-type-check-item.cc\n+++ b/gcc/rust/typecheck/rust-hir-type-check-item.cc\n@@ -283,13 +283,15 @@ TypeCheckItem::visit (HIR::StructStruct &struct_decl)\n RustIdent ident{path, struct_decl.get_locus ()};\n \n // its a single variant ADT\n+ auto variant_type = struct_decl.is_unit_struct ()\n+\t\t\t? TyTy::VariantDef::VariantType::UNIT\n+\t\t\t: TyTy::VariantDef::VariantType::STRUCT;\n std::vector variants;\n variants.push_back (\n new TyTy::VariantDef (struct_decl.get_mappings ().get_hirid (),\n \t\t\t struct_decl.get_mappings ().get_defid (),\n \t\t\t struct_decl.get_identifier ().as_string (), ident,\n-\t\t\t TyTy::VariantDef::VariantType::STRUCT, tl::nullopt,\n-\t\t\t std::move (fields)));\n+\t\t\t variant_type, tl::nullopt, std::move (fields)));\n \n // Process #[repr(X)] attribute, if any\n const AST::AttrVec &attrs = struct_decl.get_outer_attrs ();\ndiff --git a/gcc/rust/typecheck/rust-hir-type-check-pattern.cc b/gcc/rust/typecheck/rust-hir-type-check-pattern.cc\nindex 32b13714154..d6117c38f78 100644\n--- a/gcc/rust/typecheck/rust-hir-type-check-pattern.cc\n+++ b/gcc/rust/typecheck/rust-hir-type-check-pattern.cc\n@@ -73,7 +73,7 @@ TypeCheckPattern::visit (HIR::PathInExpression &pattern)\n HirId def_id = definition_id.value ();\n \n tl::optional hir_item = mappings.lookup_hir_item (def_id);\n- // If the path refrerences an item, it must be constants or structs.\n+ // If the path references an item, it must be constants or structs.\n if (hir_item.has_value ())\n \t{\n \t HIR::Item *item = hir_item.value ();\n@@ -127,7 +127,9 @@ TypeCheckPattern::visit (HIR::PathInExpression &pattern)\n \t rust_assert (ok);\n \t}\n \n- if (variant->get_variant_type () != TyTy::VariantDef::VariantType::NUM)\n+ if (variant->get_variant_type () != TyTy::VariantDef::VariantType::NUM\n+\t && variant->get_variant_type ()\n+\t != TyTy::VariantDef::VariantType::UNIT)\n \t{\n \t std::string variant_type = TyTy::VariantDef::variant_type_string (\n \t variant->get_variant_type ());\ndiff --git a/gcc/rust/typecheck/rust-tyty-variance-analysis.cc b/gcc/rust/typecheck/rust-tyty-variance-analysis.cc\nindex d640d55d8c0..ca8e9f6b1a8 100644\n--- a/gcc/rust/typecheck/rust-tyty-variance-analysis.cc\n+++ b/gcc/rust/typecheck/rust-tyty-variance-analysis.cc\n@@ -241,7 +241,8 @@ GenericTyVisitorCtx::process_type (ADTType &ty)\n \n for (const auto &variant : ty.get_variants ())\n {\n- if (variant->get_variant_type () != VariantDef::NUM)\n+ if (variant->get_variant_type () != VariantDef::NUM\n+\t && variant->get_variant_type () != VariantDef::UNIT)\n \t{\n \t for (const auto &field : variant->get_fields ())\n \t add_constraints_from_ty (field->get_field_type (),\ndiff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc\nindex e27577e311d..69ee43c2750 100644\n--- a/gcc/rust/typecheck/rust-tyty.cc\n+++ b/gcc/rust/typecheck/rust-tyty.cc\n@@ -726,7 +726,9 @@ BaseType::contains_infer () const\n \t{\n \t bool is_num_variant\n \t = variant->get_variant_type () == VariantDef::VariantType::NUM;\n-\t if (is_num_variant)\n+\t bool is_unit_variant\n+\t = variant->get_variant_type () == VariantDef::VariantType::UNIT;\n+\t if (is_num_variant || is_unit_variant)\n \t continue;\n \n \t for (auto &field : variant->get_fields ())\n@@ -831,7 +833,9 @@ BaseType::is_concrete () const\n \t{\n \t bool is_num_variant\n \t = variant->get_variant_type () == VariantDef::VariantType::NUM;\n-\t if (is_num_variant)\n+\t bool is_unit_variant\n+\t = variant->get_variant_type () == VariantDef::VariantType::UNIT;\n+\t if (is_num_variant || is_unit_variant)\n \t continue;\n \n \t for (auto &field : variant->get_fields ())\n@@ -1508,6 +1512,8 @@ VariantDef::variant_type_string (VariantType type)\n return \"tuple\";\n case STRUCT:\n return \"struct\";\n+ case UNIT:\n+ return \"unit struct\";\n }\n rust_unreachable ();\n return \"\";\n@@ -1532,7 +1538,8 @@ VariantDef::VariantDef (HirId id, DefId defid, std::string identifier,\n discriminant (std::move (discriminant)), fields (fields)\n {\n rust_assert ((type == VariantType::NUM && fields.empty ())\n-\t || (type == VariantType::TUPLE || type == VariantType::STRUCT));\n+\t || (type == VariantType::UNIT && fields.empty ())\n+\t || type == VariantType::TUPLE || type == VariantType::STRUCT);\n }\n \n VariantDef &\ndiff --git a/gcc/rust/typecheck/rust-tyty.h b/gcc/rust/typecheck/rust-tyty.h\nindex 4072b2f0bcd..516f460e625 100644\n--- a/gcc/rust/typecheck/rust-tyty.h\n+++ b/gcc/rust/typecheck/rust-tyty.h\n@@ -828,7 +828,8 @@ public:\n {\n NUM,\n TUPLE,\n- STRUCT\n+ STRUCT,\n+ UNIT\n };\n \n static std::string variant_type_string (VariantType type);\ndiff --git a/gcc/testsuite/rust/compile/match-struct-path.rs b/gcc/testsuite/rust/compile/match-struct-path.rs\nindex 5664c21b421..bc2dd43a65d 100644\n--- a/gcc/testsuite/rust/compile/match-struct-path.rs\n+++ b/gcc/testsuite/rust/compile/match-struct-path.rs\n@@ -8,3 +8,9 @@ pub fn foo(v: S) {\n S => ()\n }\n }\n+\n+pub fn bar(v: S) {\n+ match v {\n+ crate::S => ()\n+ }\n+}\n","prefixes":["COMMITTED","08/43"]}