- Member access on a struct returned by the assignment expression, cause crash #2947

releasenotes.md

@@ -46,6 +46,7 @@
 - `--safe=no` disabled compile-time errors on compile-time known runtime @require checks #2936
 - On assert known false, the message was not show for no-args.
 - Adding the incorrect sized vector to a pointer vector would cause a crash.
+- Member access on a struct returned by the assignment expression, cause crash #2947
 
 ## 0.7.9 Change list
 

src/compiler/llvm_codegen_expr.c

@@ -216,7 +216,14 @@ BEValue llvm_emit_assign_expr(GenContext *c, BEValue *ref, Expr *ref_expr, Expr
 			if (ref_expr && c->current_block) llvm_emit_expr(c, ref, ref_expr);
 		}
 		if (!c->current_block) goto AFTER_STORE;
-		if (value.type != type_void) llvm_store(c, ref, &value);
+		if (value.type == type_void)
+		{
+			value = *ref;
+		}
+		else
+		{
+			llvm_store(c, ref, &value);
+		}
 	}
 
 	if (optional)

test/test_suite/expressions/assign_from_call_to_struct.c3t

@@ -0,0 +1,28 @@
+// #target: macos-x64
+module test;
+struct Test
+{
+	long a;
+	long b;
+	char c;
+}
+
+fn Test f() => {};
+
+fn int main()
+{
+	Test t;
+	(t = f()).b;
+	return 0;
+}
+
+/* #expect: test.ll
+
+define i32 @main() #0 {
+entry:
+  %t = alloca %Test, align 8
+  call void @llvm.memset.p0.i64(ptr align 8 %t, i8 0, i64 24, i1 false)
+  call void @test.f(ptr sret(%Test) align 8 %t)
+  %ptradd = getelementptr inbounds i8, ptr %t, i64 8
+  ret i32 0
+}