ps5: function prologue

ps5/src/generator.c

@@ -120,6 +120,30 @@ static void generate_function(symbol_t* function)
 
   // TODO (Task 3.1): Do the prologue, including call frame building and parameter pushing
   // Tip: use the definitions REGISTER_PARAMS and NUM_REGISTER_PARAMS at the top of this file
+  LABEL(".%s", function->name);
+
+  PUSHQ(RBP);
+  MOVQ(RSP, RBP);
+
+  symbol_table_t *symtable = function->function_symtable;
+  for (int i = 0; i < symtable->n_symbols; i++) {
+    symbol_t *sym = symtable->children[i];
+    switch (sym->type) {
+    case SYMBOL_PARAMETER:
+      if (i < NUM_REGISTER_PARAMS) {
+        PUSHQ(REGISTER_PARAMS[i]);
+      } else {
+        /* these params are already on the stack */;
+      }
+      break;
+    case SYMBOL_LOCAL_VAR:
+      PUSHQ("$0");
+      break;
+    default:
+      fprintf(stderr, "unexpected symbol in symtable");
+      exit(EXIT_FAILURE);
+    }
+  }
 
   // TODO (Task 4): the function body can be sent to generate_statement()