From: Owen Avery <powerboat9.gamer@gmail.com>
Date: Fri, 3 May 2024 00:58:49 +0000 (-0400)
Subject: gccrs: Improve matching on non-enum ADTs
X-Git-Tag: basepoints/gcc-16~1448
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7b9e2b5d8b901e90b43d15acc62f02efa3c866bd;p=thirdparty%2Fgcc.git

gccrs: Improve matching on non-enum ADTs

gcc/rust/ChangeLog:

	* backend/rust-compile-expr.cc
	(check_match_scrutinee): Add assertion.
	* backend/rust-compile-pattern.cc
	(CompilePatternCheckExpr::visit):
	Handle HIR::PathInExpression matching a non-enum.

gcc/testsuite/ChangeLog:

	* rust/compile/match-struct-path.rs: New test.

Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>
---

diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc
index ac85628d03c..52318a973aa 100644
--- a/gcc/rust/backend/rust-compile-expr.cc
+++ b/gcc/rust/backend/rust-compile-expr.cc
@@ -956,6 +956,8 @@ check_match_scrutinee (HIR::MatchExpr &expr, Context *ctx)
       TyTy::ADTType *adt = static_cast<TyTy::ADTType *> (scrutinee_expr_tyty);
       if (adt->is_enum ())
 	rust_assert (adt->number_of_variants () > 0);
+      else
+	rust_assert (adt->number_of_variants () == 1);
     }
   else if (scrutinee_kind == TyTy::TypeKind::FLOAT)
     {
diff --git a/gcc/rust/backend/rust-compile-pattern.cc b/gcc/rust/backend/rust-compile-pattern.cc
index 86063202bf8..ffa1fa7f5dc 100644
--- a/gcc/rust/backend/rust-compile-pattern.cc
+++ b/gcc/rust/backend/rust-compile-pattern.cc
@@ -35,11 +35,16 @@ CompilePatternCheckExpr::visit (HIR::PathInExpression &pattern)
 				      &lookup);
   rust_assert (ok);
 
-  // this must be an enum
-  // TODO: might not be
+  // must be an ADT (?)
   rust_assert (lookup->get_kind () == TyTy::TypeKind::ADT);
   TyTy::ADTType *adt = static_cast<TyTy::ADTType *> (lookup);
-  rust_assert (adt->is_enum ());
+
+  // if this isn't an enum, always succeed
+  if (!adt->is_enum ())
+    {
+      check_expr = boolean_true_node;
+      return;
+    }
 
   // lookup the variant
   HirId variant_id;
diff --git a/gcc/testsuite/rust/compile/match-struct-path.rs b/gcc/testsuite/rust/compile/match-struct-path.rs
new file mode 100644
index 00000000000..acadcdb87ad
--- /dev/null
+++ b/gcc/testsuite/rust/compile/match-struct-path.rs
@@ -0,0 +1,7 @@
+pub struct S;
+
+pub fn foo(v: S) {
+    match v {
+        S => ()
+    }
+}