From: Zhi Heng <yapzhhg@gmail.com>
Date: Sat, 28 Jun 2025 12:59:54 +0000 (+0800)
Subject: gccrs: Fix type checking logic for TuplePattern
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=0803c00cdddb88bf9cfca5ad1958105d66cf04c7;p=thirdparty%2Fgcc.git

gccrs: Fix type checking logic for TuplePattern

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-pattern.cc (visit(TuplePattern)): Fix
		incorrect logic for field size checking.

gcc/testsuite/ChangeLog:

	* rust/compile/tuple_mismatch.rs: Include RestPattern in test.

Signed-off-by: Yap Zhi Heng <yapzhhg@gmail.com>
---

diff --git a/gcc/rust/typecheck/rust-hir-type-check-pattern.cc b/gcc/rust/typecheck/rust-hir-type-check-pattern.cc
index d87916ec798..537c3491265 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-pattern.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-pattern.cc
@@ -511,12 +511,12 @@ TypeCheckPattern::visit (HIR::TuplePattern &pattern)
 	HIR::TuplePatternItemsRanged &ref
 	  = static_cast<HIR::TuplePatternItemsRanged &> (pattern.get_items ());
 
-	// Check whether size of lower and upper patterns <= parent size
 	const auto &lower = ref.get_lower_patterns ();
 	const auto &upper = ref.get_upper_patterns ();
 	size_t min_size_required = lower.size () + upper.size ();
 
-	if (par.get_fields ().size () > min_size_required)
+	// Ensure that size of lower and upper patterns <= parent size
+	if (min_size_required > par.get_fields ().size ())
 	  {
 	    emit_pattern_size_error (pattern, par.get_fields ().size (),
 				     min_size_required);
diff --git a/gcc/testsuite/rust/compile/tuple_mismatch.rs b/gcc/testsuite/rust/compile/tuple_mismatch.rs
index 828586b0f09..1ff358be60a 100644
--- a/gcc/testsuite/rust/compile/tuple_mismatch.rs
+++ b/gcc/testsuite/rust/compile/tuple_mismatch.rs
@@ -3,6 +3,7 @@ fn main() {
     let (_,) = (1, 2); // { dg-error "expected a tuple with 2 elements, found one with 1 element" }
     let (_, _) = (1, 2, 3); // { dg-error "expected a tuple with 3 elements, found one with 2 elements" }
     let (_, _) = (1,); // { dg-error "expected a tuple with 1 element, found one with 2 elements" }
+    let (_, .., _) = (1,); // { dg-error "expected a tuple with 1 element, found one with 2 elements" }
 }
 
 // The lhs and rhs sizes don't match, but we still resolve 'a' to be bool, we don't