let's go we can parse return zero most useful program ever

1 files changed, 90 insertions, 0 deletions

diff --git a/ast.c b/ast.c
new file mode 100644
index 0000000..3bcc637
--- /dev/null
+++ b/ast.c
@@ -0,0 +1,90 @@
+#include "ast.h"
+#include <stdlib.h>
+
+static void expr_destroy(struct expr_node* node);
+static void stmt_destroy(struct stmt_node* node);
+
+static void type_destroy(struct type_node* node) {
+    free(node->type);
+}
+
+static void var_decl_destroy(struct var_decl_node* node) {
+    type_destroy(&node->type);
+
+    free(node->ident);
+}
+
+static void group_destroy(struct group_node* node) {
+    struct stmt_node* body_node = node->body_head;
+    while (body_node != NULL) {
+        struct stmt_node* next = body_node->next;
+        stmt_destroy(body_node);
+        free(body_node);
+        body_node = next;
+    }
+}
+
+static void fn_decl_destroy(struct fn_decl_node* node) {
+    type_destroy(&node->return_type);
+
+    free(node->name);
+
+    struct var_decl_node* args_node = node->args_head;
+    while (args_node != NULL) {
+        struct var_decl_node* next = args_node->next;
+        var_decl_destroy(args_node);
+        free(args_node);
+        args_node = next;
+    }
+
+    group_destroy(&node->body);
+}
+
+static void return_destroy(struct return_node* node) {
+    if (node->ret_val != NULL) {
+        expr_destroy(node->ret_val);
+        free(node->ret_val);
+    }
+}
+
+static void expr_destroy(struct expr_node* node) {
+    switch (node->type) {
+        case EXPR_EMPTY:
+        case EXPR_INT_LIT:
+            break;
+        case EXPR_VAR_DECL:
+            var_decl_destroy(&node->as._var_decl);
+            break;
+        case EXPR_RETURN:
+            return_destroy(&node->as._return);
+            break;
+    }
+}
+
+static void stmt_destroy(struct stmt_node* node) {
+    switch (node->type) {
+        case STMT_EXPR:
+            expr_destroy(&node->as._expr);
+            break;
+        case STMT_GROUP:
+            group_destroy(&node->as._group);
+    }
+}
+
+static void root_node_destroy(struct root_node* node) {
+    switch (node->type) {
+        case ROOT_FN_DECL:
+            fn_decl_destroy(&node->as._fn_decl);
+            break;
+    }
+}
+
+void ast_destroy(struct root_node* head) {
+    struct root_node* node = head;
+    while (node != NULL) {
+        struct root_node* next = node->next;
+        root_node_destroy(node);
+        free(node);
+        node = next;
+    }
+}