From 841c2f15e506fe9153ee32dc39eb9a0bdab480d8 Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Sat, 17 Feb 2018 12:55:50 -0800
Subject: [PATCH] Add function to free tree nodes.

---
 CMakeLists.txt |  2 +-
 include/tree.h |  8 ++++++++
 src/tree.c     | 22 ++++++++++++++++++++++
 3 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 src/tree.c

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 03c98d1..d21fff8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ project(libabacus)
 
 add_compile_options(-pedantic -Wall)
 
-add_library(abacus STATIC src/lexer.c src/util.c src/table.c src/parser.c src/libabacus.c)
+add_library(abacus STATIC src/lexer.c src/util.c src/table.c src/parser.c src/libabacus.c src/tree.c)
 add_executable(libabacus src/main.c)
 add_subdirectory(external/liblex)
 
diff --git a/include/tree.h b/include/tree.h
index 0ce7ebb..f9990c2 100644
--- a/include/tree.h
+++ b/include/tree.h
@@ -73,4 +73,12 @@ struct libab_tree_s {
 typedef enum libab_tree_variant_e libab_tree_variant;
 typedef struct libab_tree_s libab_tree;
 
+/**
+ * Frees the given tree, using its
+ * variant as a hint as to what
+ * variables need to be freed.
+ * @param tree the tree to free.
+ */
+void libab_tree_free(libab_tree* tree);
+
 #endif
diff --git a/src/tree.c b/src/tree.c
new file mode 100644
index 0000000..70f10d7
--- /dev/null
+++ b/src/tree.c
@@ -0,0 +1,22 @@
+#include "tree.h"
+#include <stdlib.h>
+
+void libab_tree_free(libab_tree* tree) {
+    int free_string = 0;
+    int free_vector = 0;
+    if(tree->variant == BASE || tree->variant == OP ||
+            tree->variant == UNARY_OP || tree->variant == BLOCK ||
+            tree->variant == FUN || tree->variant == IF ||
+            tree->variant == WHILE || tree->variant == DOWHILE ||
+            tree->variant == FOR || tree->variant == CALL ||
+            tree->variant == RETURN) {
+        free_vector = 1;
+    }
+    if(tree->variant == ID || tree->variant == STR || tree->variant == NUM ||
+            tree->variant == KW || tree->variant == OP || tree->variant == UNARY_OP ||
+            tree->variant == FUN || tree->variant == CALL) {
+        free_string = 1;
+    }
+    if(free_string) free(tree->string_value);
+    if(free_vector) vec_free(&tree->children);
+}