From bb6c6817808a9e2423f80caa42055d96c8b8e7b6 Mon Sep 17 00:00:00 2001
From: Dominic Grimm <dominic@dergrimm.net>
Date: Sat, 5 Aug 2023 12:52:28 +0200
Subject: [PATCH] Fix memory leak by adding "owner" concept of node

---
 include/hydroforth/parser.h  |  1 +
 src/hydroforth/interpreter.c | 18 +++++++++---------
 src/hydroforth/parser.c      |  7 +++++++
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/include/hydroforth/parser.h b/include/hydroforth/parser.h
index 4325b54..0dc93dd 100644
--- a/include/hydroforth/parser.h
+++ b/include/hydroforth/parser.h
@@ -60,6 +60,7 @@ union hf__node_value {
 struct hf__node {
   enum hf__node_type type;
   union hf__node_value value;
+  bool is_owner;
 };
 
 struct hf__parser {
diff --git a/src/hydroforth/interpreter.c b/src/hydroforth/interpreter.c
index ed83dec..2941a8d 100644
--- a/src/hydroforth/interpreter.c
+++ b/src/hydroforth/interpreter.c
@@ -7,6 +7,11 @@
 
 void free_word_def_value(void *x) {
   struct hf__interpreter__word *word = x;
+
+  for (size_t i = 0; i < word->body_len; i++) {
+    // TODO: free nodes
+  }
+
   free(word->body);
   free(word);
 }
@@ -54,17 +59,12 @@ struct hf__result words__word(struct hf__interpreter *const interpreter,
     hf__parser__node_array_push(
         &interpreter->call_stack, &interpreter->call_stack_len,
         &interpreter->call_stack_size, (*word)->body[i]);
+    interpreter->call_stack[interpreter->call_stack_len - 1].is_owner = false;
   }
 
-  /* FIXME: Word name points to copy of pointer of original name,
-    when cleared here all other references loose access to the pointer's value
-    => SIGSEV!
-
-    For now I am going to ignore the memory leak.
-    Copying the word name may be a better option but is pretty memory
-    inefficient.
-  */
-  // free(node->value.word.value);
+  if (node->is_owner) {
+    free(node->value.word.value);
+  }
 
   return HF__OK;
 }
diff --git a/src/hydroforth/parser.c b/src/hydroforth/parser.c
index 53acf2d..ba4df45 100644
--- a/src/hydroforth/parser.c
+++ b/src/hydroforth/parser.c
@@ -145,6 +145,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
           (struct hf__node){
               .type = HF__NODE_TYPE__NUMBER,
               .value = {.number = negative ? -number : number},
+              .is_owner = true,
           });
       break;
     }
@@ -194,6 +195,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
                                   (struct hf__node){
                                       .type = HF__NODE_TYPE__CHAR,
                                       .value = {.ch = ch},
+                                      .is_owner = true,
                                   });
       break;
     }
@@ -218,6 +220,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
         node = (struct hf__node){
             .type = HF__NODE_TYPE__WORD,
             .value = {.word = {.hash = hash, .value = lower_s}},
+            .is_owner = true,
         };
       } else {
         node.type = **type_ptr;
@@ -302,6 +305,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
                                   (struct hf__node){
                                       .type = HF__NODE_TYPE__WORD_DEF,
                                       .value = {.word_def = word_def},
+                                      .is_owner = true,
                                   });
 
       break;
@@ -323,6 +327,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
                                                   src, tokens[i].location.start,
                                                   tokens[i].location.end),
                                           },
+                                      .is_owner = true,
                                   });
       break;
 
@@ -336,6 +341,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
                                                   src, tokens[i].location.start,
                                                   tokens[i].location.end),
                                           },
+                                      .is_owner = true,
                                   });
       break;
 
@@ -349,6 +355,7 @@ struct hf__result hf__parse(struct hf__parser *const parser,
                                                   src, tokens[i].location.start,
                                                   tokens[i].location.end),
                                           },
+                                      .is_owner = true,
                                   });
       break;