Fix #4445

1 files changed, 26 insertions, 19 deletions

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index fcdabedde..71079b4a1 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -5884,12 +5884,12 @@ typedef u32 UnpackFlags;
 enum UnpackFlag : u32 {
 	UnpackFlag_None       = 0,
 	UnpackFlag_AllowOk    = 1<<0,
-	UnpackFlag_IsVariadic = 1<<1,
-	UnpackFlag_AllowUndef = 1<<2,
+	UnpackFlag_AllowUndef = 1<<1,
 };
 
 
-gb_internal bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize lhs_count, Array<Operand> *operands, Slice<Ast *> const &rhs_arguments, UnpackFlags flags) {
+gb_internal bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize lhs_count, Array<Operand> *operands, Slice<Ast *> const &rhs_arguments, UnpackFlags flags,
+	isize variadic_index = -1) {
 	auto const &add_dependencies_from_unpacking = [](CheckerContext *c, Entity **lhs, isize lhs_count, isize tuple_index, isize tuple_count) -> isize {
 		if (lhs == nullptr || c->decl == nullptr) {
 			return tuple_count;
@@ -5914,10 +5914,12 @@ gb_internal bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize
 		return tuple_count;
 	};
 
-
 	bool allow_ok    = (flags & UnpackFlag_AllowOk) != 0;
-	bool is_variadic = (flags & UnpackFlag_IsVariadic) != 0;
 	bool allow_undef = (flags & UnpackFlag_AllowUndef) != 0;
+	
+	if (variadic_index < 0) {
+		variadic_index = lhs_count;
+	}
 
 	bool optional_ok = false;
 	isize tuple_index = 0;
@@ -5934,8 +5936,7 @@ gb_internal bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize
 
 		Type *type_hint = nullptr;
 
-
-		if (lhs != nullptr && tuple_index < lhs_count) {
+		if (lhs != nullptr && tuple_index < variadic_index) {
 			// NOTE(bill): override DeclInfo for dependency
 			Entity *e = lhs[tuple_index];
 			if (e != nullptr) {
@@ -5946,9 +5947,9 @@ gb_internal bool check_unpack_arguments(CheckerContext *ctx, Entity **lhs, isize
 					type_hint = e->type->Slice.elem;
 				}
 			}
-		} else if (lhs != nullptr && tuple_index >= lhs_count && is_variadic) {
+		} else if (lhs != nullptr && tuple_index >= variadic_index) {
 			// NOTE(bill): override DeclInfo for dependency
-			Entity *e = lhs[lhs_count-1];
+			Entity *e = lhs[variadic_index];
 			if (e != nullptr) {
 				type_hint = e->type;
 				if (e->flags & EntityFlag_Ellipsis) {
@@ -6493,7 +6494,7 @@ gb_internal bool is_call_expr_field_value(AstCallExpr *ce) {
 	return ce->args[0]->kind == Ast_FieldValue;
 }
 
-gb_internal Entity **populate_proc_parameter_list(CheckerContext *c, Type *proc_type, isize *lhs_count_, bool *is_variadic) {
+gb_internal Entity **populate_proc_parameter_list(CheckerContext *c, Type *proc_type, isize *lhs_count_) {
 	Entity **lhs = nullptr;
 	isize lhs_count = -1;
 
@@ -6503,7 +6504,6 @@ gb_internal Entity **populate_proc_parameter_list(CheckerContext *c, Type *proc_
 
 	GB_ASSERT(is_type_proc(proc_type));
 	TypeProc *pt = &base_type(proc_type)->Proc;
-	*is_variadic = pt->variadic;
 
 	if (!pt->is_polymorphic || pt->is_poly_specialized) {
 		if (pt->params != nullptr) {
@@ -6833,7 +6833,7 @@ gb_internal CallArgumentData check_call_arguments_proc_group(CheckerContext *c,
 
 	Entity **lhs = nullptr;
 	isize lhs_count = -1;
-	bool is_variadic = false;
+	i32 variadic_index = -1;
 
 	auto positional_operands = array_make<Operand>(heap_allocator(), 0, 0);
 	auto named_operands = array_make<Operand>(heap_allocator(), 0, 0);
@@ -6842,9 +6842,13 @@ gb_internal CallArgumentData check_call_arguments_proc_group(CheckerContext *c,
 
 	if (procs.count == 1) {
 		Entity *e = procs[0];
-
-		lhs = populate_proc_parameter_list(c, e->type, &lhs_count, &is_variadic);
-		check_unpack_arguments(c, lhs, lhs_count, &positional_operands, positional_args, is_variadic ? UnpackFlag_IsVariadic : UnpackFlag_None);
+		TypeProc *pt = &base_type(e->type)->Proc;
+		
+		lhs = populate_proc_parameter_list(c, e->type, &lhs_count);
+		if (pt->variadic) {
+			variadic_index = pt->variadic_index;
+		}
+		check_unpack_arguments(c, lhs, lhs_count, &positional_operands, positional_args, UnpackFlag_None, variadic_index);
 
 		if (check_named_arguments(c, e->type, named_args, &named_operands, true)) {
 			check_call_arguments_single(c, call, operand,
@@ -6908,7 +6912,7 @@ gb_internal CallArgumentData check_call_arguments_proc_group(CheckerContext *c,
 		}
 	}
 
-	check_unpack_arguments(c, lhs, lhs_count, &positional_operands, positional_args, is_variadic ? UnpackFlag_IsVariadic : UnpackFlag_None);
+	check_unpack_arguments(c, lhs, lhs_count, &positional_operands, positional_args, UnpackFlag_None, variadic_index);
 
 	for_array(i, named_args) {
 		Ast *arg = named_args[i];
@@ -7347,12 +7351,15 @@ gb_internal CallArgumentData check_call_arguments(CheckerContext *c, Operand *op
 
 	if (positional_args.count > 0) {
 		isize lhs_count = -1;
-		bool is_variadic = false;
 		Entity **lhs =  nullptr;
+		i32 variadic_index = -1;
 		if (pt != nullptr)  {
-			lhs = populate_proc_parameter_list(c, proc_type, &lhs_count, &is_variadic);
+			lhs = populate_proc_parameter_list(c, proc_type, &lhs_count);
+			if (pt->variadic) {
+				variadic_index = pt->variadic_index;
+			}
 		}
-		check_unpack_arguments(c, lhs, lhs_count, &positional_operands, positional_args, is_variadic ? UnpackFlag_IsVariadic : UnpackFlag_None);
+		check_unpack_arguments(c, lhs, lhs_count, &positional_operands, positional_args, UnpackFlag_None, variadic_index);
 	}
 
 	if (named_args.count > 0) {