frontend: update codegen usage to only use pre-order ast traversal

frontend/cmd/compile.c

@@ -16,6 +16,7 @@ enum {
 	ARG_SOURCE_FILE = 200,
 	OPT_SHOW_LEX_TOKENS,
 	OPT_SHOW_AST_NODES,
+	OPT_SHOW_AST_NODES_POST,
 	OPT_SHOW_IR,
 };
 
@@ -23,8 +24,14 @@ static enum ivy_status node_codegen(
 	struct ivy_ast_node *node, enum ivy_ast_iteration_type iteration_type,
 	struct ivy_ast_node_iterator *it, void *arg)
 {
+	if (iteration_type != IVY_AST_ITERATION_PRE) {
+		return IVY_OK;
+	}
+
 	struct ivy_codegen *gen = arg;
-	return ivy_codegen_push_node(gen, node, iteration_type);
+	struct print_ast_node_args print_args = {.postorder = true};
+	print_ast_node(node, iteration_type, it, &print_args);
+	return ivy_codegen_push_node(gen, node, node->n_it.it_depth);
 }
 
 static int compile_file(const char *path, const b_arglist *args)
@@ -35,6 +42,10 @@ static int compile_file(const char *path, const b_arglist *args)
 	bool show_ast = b_arglist_get_count(
 				args, OPT_SHOW_AST_NODES, B_COMMAND_INVALID_ID)
 	              > 0;
+	bool show_ast_post
+		= b_arglist_get_count(
+			  args, OPT_SHOW_AST_NODES_POST, B_COMMAND_INVALID_ID)
+	        > 0;
 	bool show_ir
 		= b_arglist_get_count(args, OPT_SHOW_IR, B_COMMAND_INVALID_ID) > 0;
 
@@ -108,14 +119,31 @@ static int compile_file(const char *path, const b_arglist *args)
 
 	int r = (status == IVY_OK || status == IVY_ERR_EOF) ? 0 : -1;
 	ivy_file_close(src);
+	ivy_lexer_destroy(lex);
 
-	if (r == 0 && show_ast) {
+	if (r != 0) {
+		return r;
+	}
+
+	if (show_ast) {
 		struct ivy_ast_node *root = ivy_parser_root_node(parser);
 		struct ivy_ast_node_iterator it = {0};
 		ivy_ast_node_iterate(root, &it, print_ast_node, NULL);
 	}
 
-	ivy_lexer_destroy(lex);
+	if (show_ast && show_ast_post) {
+		printf("------\n");
+	}
+
+	if (show_ast_post) {
+		struct ivy_ast_node *root = ivy_parser_root_node(parser);
+		struct ivy_ast_node_iterator it = {};
+		struct print_ast_node_args args = {
+			.indent = true,
+			.postorder = true,
+		};
+		ivy_ast_node_iterate(root, &it, print_ast_node, &args);
+	}
 
 	if (r != 0) {
 		ivy_parser_destroy(parser);
@@ -129,13 +157,15 @@ static int compile_file(const char *path, const b_arglist *args)
 
 	ivy_codegen_start_module(codegen);
 
-	struct ivy_ast_node *node = NULL;
-	while ((node = ivy_parser_dequeue_node(parser))) {
-		struct ivy_ast_node_iterator it = {0};
-		ivy_ast_node_iterate(node, &it, node_codegen, codegen);
-		ivy_ast_node_destroy(node);
+	struct ivy_ast_node *node = ivy_parser_root_node(parser);
+	struct ivy_ast_node_iterator it = {0};
+	status = ivy_ast_node_iterate(node, &it, node_codegen, codegen);
+	if (status != IVY_OK) {
+		printf("codegen failed: error %s\n", ivy_status_to_string(status));
 	}
 
+	ivy_codegen_push_eof(codegen);
+
 	struct mie_module *mod = NULL;
 	ivy_codegen_end_module(codegen, &mod);
 
@@ -200,6 +230,15 @@ B_COMMAND(CMD_COMPILE, CMD_ROOT)
 			"input files.");
 	}
 
+	B_COMMAND_OPTION(OPT_SHOW_AST_NODES_POST)
+	{
+		B_OPTION_LONG_NAME("show-ast-post");
+		B_OPTION_SHORT_NAME('A');
+		B_OPTION_DESC(
+			"print the abstract syntax tree generated from the "
+			"input files in post-order.");
+	}
+
 	B_COMMAND_OPTION(OPT_SHOW_IR)
 	{
 		B_OPTION_LONG_NAME("show-ir");