From 901145b59f14b26b01b51cb38bf96b63ad9d1ff1 Mon Sep 17 00:00:00 2001
From: Test_User <hax@andrewyu.org>
Date: Thu, 5 Sep 2024 01:55:15 -0400
Subject: Remove UB around function/non-function pointer casting (by stuff
 using this)

---
 hax_table.c | 40 ++++++++++++++++++++++++----------------
 hax_table.h | 17 ++++++++++++-----
 2 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/hax_table.c b/hax_table.c
index 0b89a35..c2c82a3 100644
--- a/hax_table.c
+++ b/hax_table.c
@@ -102,7 +102,7 @@ static inline size_t search(struct table tbl, struct string name, char *exists)
 	}
 }
 
-int set_table_index(struct table *tbl, struct string name, void *ptr) {
+int set_table_index(struct table *tbl, struct string name, union table_ptr ptr) {
 	char exists;
 	size_t index = search(*tbl, name, &exists);
 
@@ -132,11 +132,10 @@ int set_table_index(struct table *tbl, struct string name, void *ptr) {
 	return 0;
 }
 
-void * get_table_index(struct table tbl, struct string name) {
-	char exists;
-	size_t index = search(tbl, name, &exists);
-	if (!exists)
-		return 0;
+union table_ptr get_table_index(struct table tbl, struct string name, char *exists) {
+	size_t index = search(tbl, name, exists);
+	if (!*exists)
+		return (union table_ptr){0};
 
 	return tbl.array[index].ptr;
 }
@@ -147,14 +146,13 @@ char has_table_index(struct table tbl, struct string name) {
 	return exists;
 }
 
-void * remove_table_index(struct table *tbl, struct string name) {
-	char exists;
-	size_t index = search(*tbl, name, &exists);
+union table_ptr get_and_remove_table_index(struct table *tbl, struct string name, char *exists) {
+	size_t index = search(*tbl, name, exists);
 
-	if (!exists)
-		return 0;
+	if (!*exists)
+		return (union table_ptr){0};
 
-	void *ptr = tbl->array[index].ptr;
+	union table_ptr ptr = tbl->array[index].ptr;
 	free(tbl->array[index].name.data);
 
 	memmove(&(tbl->array[index]), &(tbl->array[index+1]), (tbl->len - index - 1) * sizeof(*(tbl->array)));
@@ -168,6 +166,12 @@ void * remove_table_index(struct table *tbl, struct string name) {
 	return ptr;
 }
 
+void remove_table_index(struct table *tbl, struct string name) {
+	char exists;
+	get_and_remove_table_index(tbl, name, &exists);
+	return;
+}
+
 void clear_table(struct table *tbl) {
 	for (size_t i = 0; i < tbl->len; i++)
 		free(tbl->array[i].name.data);
@@ -181,10 +185,14 @@ size_t get_table_offset(struct table tbl, struct string name, char *exists) {
 }
 
 // TODO: Proper lookup
-void * get_table_prefix(struct table tbl, struct string name) {
-	for (size_t i = 0; i < tbl.len; i++)
-		if (tbl.array[i].name.len <= name.len && memcmp(tbl.array[i].name.data, name.data, tbl.array[i].name.len) == 0)
+union table_ptr get_table_prefix(struct table tbl, struct string name, char *exists) {
+	for (size_t i = 0; i < tbl.len; i++) {
+		if (tbl.array[i].name.len <= name.len && memcmp(tbl.array[i].name.data, name.data, tbl.array[i].name.len) == 0) {
+			*exists = 1;
 			return tbl.array[i].ptr;
+		}
+	}
 
-	return 0;
+	*exists = 0;
+	return (union table_ptr){0};
 }
diff --git a/hax_table.h b/hax_table.h
index 90cbbdb..5db58ee 100644
--- a/hax_table.h
+++ b/hax_table.h
@@ -30,9 +30,15 @@
 
 #include "hax_string.h"
 
+// because C and function pointers vs non-function pointers
+union table_ptr {
+	void *data;
+	void (*function)(void);
+};
+
 struct table_index {
 	struct string name;
-	void *ptr;
+	union table_ptr ptr;
 };
 
 struct table {
@@ -40,12 +46,13 @@ struct table {
 	size_t len;
 };
 
-extern int set_table_index(struct table *tbl, struct string name, void *ptr);
-extern void * get_table_index(struct table tbl, struct string name);
+extern int set_table_index(struct table *tbl, struct string name, union table_ptr ptr);
+extern union table_ptr get_table_index(struct table tbl, struct string name, char *exists);
 extern char has_table_index(struct table tbl, struct string name);
-extern void * remove_table_index(struct table *tbl, struct string name); // returns same as get_table_index
+extern void remove_table_index(struct table *tbl, struct string name);
+extern union table_ptr get_and_remove_table_index(struct table *tbl, struct string name, char *exists); // returns same as get_table_index
 extern void clear_table(struct table *tbl);
 extern size_t get_table_offset(struct table tbl, struct string name, char *exists);
 
 // Longest index that <name> starts with
-extern void * get_table_prefix(struct table tbl, struct string name);
+extern union table_ptr get_table_prefix(struct table tbl, struct string name, char *exists);
-- 
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