gccrs: fix bug in pattern check for tuples

We can point to generic parent types which means we need to do the shallow resolve thing that rustc does. We have destructure which is similar to get what the parameter type points to. Fixes #2775 gcc/rust/ChangeLog: * typecheck/rust-hir-type-check-pattern.cc (TypeCheckPattern::visit): use destructure gcc/testsuite/ChangeLog: * rust/compile/issue-2775.rs: New test. Signed-off-by: Philip Herron <[email protected]>
Rust-GCC · Feb 5, 2024 · 38af9fe · 38af9fe
1 parent e2cb2a7
commit 38af9fe
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Showing 2 changed files with 15 additions and 2 deletions.
diff --git a/gcc/rust/typecheck/rust-hir-type-check-pattern.cc b/gcc/rust/typecheck/rust-hir-type-check-pattern.cc
@@ -302,7 +302,8 @@ TypeCheckPattern::visit (HIR::TuplePattern &pattern)
 	  = *static_cast<HIR::TuplePatternItemsMultiple *> (
 	    pattern.get_items ().get ());
 
-	if (parent->get_kind () != TyTy::TUPLE)
+	auto resolved_parent = parent->destructure ();
+	if (resolved_parent->get_kind () != TyTy::TUPLE)
 	  {
 	    rust_error_at (pattern.get_locus (), "expected %s, found tuple",
 			   parent->as_string ().c_str ());
@@ -312,7 +313,8 @@ TypeCheckPattern::visit (HIR::TuplePattern &pattern)
 	const auto &patterns = ref.get_patterns ();
 	size_t nitems_to_resolve = patterns.size ();
 
-	TyTy::TupleType &par = *static_cast<TyTy::TupleType *> (parent);
+	TyTy::TupleType &par
+	  = *static_cast<TyTy::TupleType *> (resolved_parent);
 	if (patterns.size () != par.get_fields ().size ())
 	  {
 	    emit_pattern_size_error (pattern, par.get_fields ().size (),

diff --git a/gcc/testsuite/rust/compile/issue-2775.rs b/gcc/testsuite/rust/compile/issue-2775.rs
@@ -0,0 +1,11 @@
+// { dg-options "-w" }
+#[lang = "sized"]
+pub trait Sized {}
+
+struct Ref<'a, T> {
+    x: &'a T,
+}
+
+pub fn test<'a, 'b, 'c>() {
+    let (_, &&Ref::<(&'_ i32, i32)> { x: &(a, b) }): (i32, &'_ &'b Ref<'b, (&'c i32, i32)>);
+}