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Remove our custom hashmap

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This commit is contained in:
Rangi42
2024-02-20 21:30:29 -05:00
committed by Sylvie
parent 95e7dac9a6
commit d53bba97e8
7 changed files with 5 additions and 204 deletions
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2
Makefile
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@@ -69,7 +69,6 @@ rgbasm_obj := \
src/extern/getopt.o \
src/extern/utf8decoder.o \
src/error.o \
src/hashmap.o \
src/linkdefs.o \
src/opmath.o \
src/util.o
@@ -89,7 +88,6 @@ rgblink_obj := \
src/extern/getopt.o \
src/extern/utf8decoder.o \
src/error.o \
src/hashmap.o \
src/linkdefs.o \
src/opmath.o \
src/util.o

70
include/hashmap.hpp
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@@ -1,70 +0,0 @@
/* SPDX-License-Identifier: MIT */
// Generic hashmap implementation (C++ templates are calling...)
#ifndef RGBDS_LINK_HASHMAP_H
#define RGBDS_LINK_HASHMAP_H
#include <assert.h>
#define HASH_NB_BITS 32
#define HALF_HASH_NB_BITS 16
static_assert(HALF_HASH_NB_BITS * 2 == HASH_NB_BITS, "");
#define HASHMAP_NB_BUCKETS (1 << HALF_HASH_NB_BITS)
// HashMapEntry is internal, please do not attempt to use it
typedef struct HashMapEntry *HashMap[HASHMAP_NB_BUCKETS];
/*
* Adds an element to a hashmap.
* @warning Adding a new element with an already-present key will not cause an
* error, this must be handled externally.
* @warning Inserting a NULL will make `hash_GetElement`'s return ambiguous!
* @param map The HashMap to add the element to
* @param key The key with which the element will be stored and retrieved
* @param element The element to add
* @return A pointer to the pointer to the element.
*/
void **hash_AddElement(HashMap map, char const *key, void *element);
/*
* Removes an element from a hashmap.
* @param map The HashMap to remove the element from
* @param key The key to search the element with
* @return True if the element was found and removed
*/
bool hash_RemoveElement(HashMap map, char const *key);
/*
* Finds an element in a hashmap, and returns a pointer to its value field.
* @param map The map to consider the elements of
* @param key The key to search an element for
* @return A pointer to the pointer to the element, or NULL if not found.
*/
void **hash_GetNode(HashMap const map, char const *key);
/*
* Finds an element in a hashmap.
* @param map The map to consider the elements of
* @param key The key to search an element for
* @return A pointer to the element, or NULL if not found. (NULL can be returned
* if such an element was added, but that sounds pretty silly.)
*/
void *hash_GetElement(HashMap const map, char const *key);
/*
* Executes a function on each element in a hashmap.
* @param map The map to consider the elements of
* @param func The function to run. The first argument will be the element,
* the second will be `arg`.
* @param arg An argument to be passed to all function calls
*/
void hash_ForEach(HashMap const map, void (*func)(void *, void *), void *arg);
/*
* Cleanly empties a hashmap from its contents.
* This does not `free` the data structure itself!
* @param map The map to empty
*/
void hash_EmptyMap(HashMap map);
#endif // RGBDS_LINK_HASHMAP_H

2
src/CMakeLists.txt
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@@ -50,7 +50,6 @@ set(rgbasm_src
"asm/symbol.cpp"
"asm/warning.cpp"
"extern/utf8decoder.cpp"
"hashmap.cpp"
"linkdefs.cpp"
"opmath.cpp"
"util.cpp"
@@ -84,7 +83,6 @@ set(rgblink_src
"link/section.cpp"
"link/symbol.cpp"
"extern/utf8decoder.cpp"
"hashmap.cpp"
"linkdefs.cpp"
"opmath.cpp"
"util.cpp"

124
src/hashmap.cpp
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@@ -1,124 +0,0 @@
/* SPDX-License-Identifier: MIT */
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "error.hpp"
#include "hashmap.hpp"
// The lower half of the hash is used to index the "master" table,
// the upper half is used to help resolve collisions more quickly
#define UINT_BITS_(NB_BITS) uint##NB_BITS##_t
#define UINT_BITS(NB_BITS) UINT_BITS_(NB_BITS)
typedef UINT_BITS(HASH_NB_BITS) HashType;
typedef UINT_BITS(HALF_HASH_NB_BITS) HalfHashType;
struct HashMapEntry {
HalfHashType hash;
char const *key;
void *content;
struct HashMapEntry *next;
};
#define FNV_OFFSET_BASIS 0x811C9DC5
#define FNV_PRIME 16777619
// FNV-1a hash
static HashType hash(char const *str)
{
HashType hash = FNV_OFFSET_BASIS;
while (*str) {
hash ^= (uint8_t)*str++;
hash *= FNV_PRIME;
}
return hash;
}
void **hash_AddElement(HashMap map, char const *key, void *element)
{
HashType hashedKey = hash(key);
HalfHashType index = hashedKey;
struct HashMapEntry *newEntry = (struct HashMapEntry *)malloc(sizeof(*newEntry));
if (!newEntry)
err("%s: Failed to allocate new entry", __func__);
newEntry->hash = hashedKey >> HALF_HASH_NB_BITS;
newEntry->key = key;
newEntry->content = element;
newEntry->next = map[index];
map[index] = newEntry;
return &newEntry->content;
}
bool hash_RemoveElement(HashMap map, char const *key)
{
HashType hashedKey = hash(key);
struct HashMapEntry **ptr = &map[(HalfHashType)hashedKey];
while (*ptr) {
if (hashedKey >> HALF_HASH_NB_BITS == (*ptr)->hash
&& !strcmp((*ptr)->key, key)) {
struct HashMapEntry *next = (*ptr)->next;
free(*ptr);
*ptr = next;
return true;
}
ptr = &(*ptr)->next;
}
return false;
}
void **hash_GetNode(HashMap const map, char const *key)
{
HashType hashedKey = hash(key);
struct HashMapEntry *ptr = map[(HalfHashType)hashedKey];
while (ptr) {
if (hashedKey >> HALF_HASH_NB_BITS == ptr->hash
&& !strcmp(ptr->key, key)) {
return &ptr->content;
}
ptr = ptr->next;
}
return NULL;
}
void *hash_GetElement(HashMap const map, char const *key)
{
void **node = hash_GetNode(map, key);
return node ? *node : NULL;
}
void hash_ForEach(HashMap const map, void (*func)(void *, void *), void *arg)
{
for (size_t i = 0; i < HASHMAP_NB_BUCKETS; i++) {
struct HashMapEntry *ptr = map[i];
while (ptr) {
func(ptr->content, arg);
ptr = ptr->next;
}
}
}
void hash_EmptyMap(HashMap map)
{
for (size_t i = 0; i < HASHMAP_NB_BUCKETS; i++) {
struct HashMapEntry *ptr = map[i];
while (ptr) {
struct HashMapEntry *next = ptr->next;
free(ptr);
ptr = next;
}
map[i] = NULL;
}
}

2
test/asm/charmap-inheritance.asm
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@@ -13,7 +13,7 @@ SECTION "test", ROM0
charmap "<FAR>", $08
; At this point, enough nodes were allocated for 'foo' to be reallocated.
; Its value in the charmaps' hashmap should have been updated too,
; Its value in the charmaps' std::map should have been updated too,
; so that usages of 'foo' will not segfault.
; This uses 'foo; by switching to it.

7
test/asm/sym-collision.asm
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@@ -1,9 +1,8 @@
; Hashmap collisions are pretty poorly-tested code path...
; At some point, `PURGE` would malfunction with them
SECTION "Collision course", OAM[$FE00]
; All the following symbols collide!
; All the following symbols used to collide with our custom hashmap,
; which at some point caused `PURGE` to malfunction with them.
; We now use C++ `std::map` which reliably handles collisions.
aqfj: ds 1 ; Give them different addresses
cxje: ds 1
dgsd: ds 1

2
test/asm/sym-collision.err
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@@ -1,3 +1,3 @@
error: sym-collision.asm(26):
error: sym-collision.asm(25):
Interpolated symbol "dork" does not exist
error: Assembly aborted (1 error)!