fix var args having wrong index when runtime param before it

closes #312

1 files changed, 5 insertions, 1 deletions

diff --git a/src/ir.cpp b/src/ir.cpp
index 79f4a27914..c7c9c6490c 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -8346,7 +8346,7 @@ static TypeTableEntry *ir_analyze_fn_call(IrAnalyze *ira, IrInstructionCall *cal
         }
 
         bool found_first_var_arg = false;
-        size_t first_var_arg = inst_fn_type_id.param_count;
+        size_t first_var_arg;
 
         FnTableEntry *parent_fn_entry = exec_fn_entry(ira->new_irb.exec);
         assert(parent_fn_entry);
@@ -8394,6 +8394,10 @@ static TypeTableEntry *ir_analyze_fn_call(IrAnalyze *ira, IrInstructionCall *cal
             AstNode *param_decl_node = fn_proto_node->data.fn_proto.params.at(next_proto_i);
             Buf *param_name = param_decl_node->data.param_decl.name;
 
+            if (!found_first_var_arg) {
+                first_var_arg = inst_fn_type_id.param_count;
+            }
+
             ConstExprValue *var_args_val = create_const_arg_tuple(ira->codegen,
                     first_var_arg, inst_fn_type_id.param_count);
             VariableTableEntry *var = add_variable(ira->codegen, param_decl_node,