ref: ecd2eb2447bf4dee4ec3be35f881c7e7102adb1b
dir: /tools/make_patch.c/
#define PROGRAM_NAME "make_patch"
#define USAGE_OPTS "labels.sym constants.sym patched.gbc original.gbc vc.patch.template vc.patch"
#include "common.h"
#include <ctype.h>
struct Buffer {
size_t item_size;
size_t size;
size_t capacity;
void *data;
};
struct Symbol {
struct Symbol *next;
unsigned int address;
unsigned int offset;
char name[]; // C99 FAM
};
struct Patch {
unsigned int offset;
unsigned int size;
};
struct Buffer *buffer_create(size_t item_size) {
struct Buffer *buffer = xmalloc(sizeof(*buffer));
buffer->item_size = item_size;
buffer->size = 0;
buffer->capacity = 0x10;
buffer->data = xmalloc(buffer->capacity * item_size);
return buffer;
}
void buffer_append(struct Buffer *buffer, const void *item) {
if (buffer->size >= buffer->capacity) {
buffer->capacity = (buffer->capacity + 1) * 2;
buffer->data = xrealloc(buffer->data, buffer->capacity * buffer->item_size);
}
memcpy((char *)buffer->data + (buffer->size++ * buffer->item_size), item, buffer->item_size);
}
void buffer_free(struct Buffer *buffer) {
free(buffer->data);
free(buffer);
}
void symbol_append(struct Symbol **symbols, const char *name, int bank, int address) {
size_t name_len = strlen(name) + 1;
struct Symbol *symbol = xmalloc(sizeof(*symbol) + name_len);
symbol->address = address;
symbol->offset = address < 0x8000
? (bank > 0 ? address + (bank - 1) * 0x4000 : address) // ROM addresses are relative to their bank
: address - 0x8000; // RAM addresses are relative to the start of all RAM
memcpy(symbol->name, name, name_len);
symbol->next = *symbols;
*symbols = symbol;
}
void symbol_free(struct Symbol *symbols) {
for (struct Symbol *next; symbols; symbols = next) {
next = symbols->next;
free(symbols);
}
}
const struct Symbol *symbol_find(const struct Symbol *symbols, const char *name) {
size_t name_len = strlen(name);
for (const struct Symbol *symbol = symbols; symbol; symbol = symbol->next) {
size_t sym_name_len = strlen(symbol->name);
if (name_len > sym_name_len) {
continue;
}
const char *sym_name = symbol->name;
if (name[0] == '.') {
// If `name` is a local label, compare it to the local part of `symbol->name`
sym_name += sym_name_len - name_len;
}
if (!strcmp(sym_name, name)) {
return symbol;
}
}
error_exit("Error: Unknown symbol: \"%s\"\n", name);
}
const struct Symbol *symbol_find_cat(const struct Symbol *symbols, const char *prefix, const char *suffix) {
char *sym_name = xmalloc(strlen(prefix) + strlen(suffix) + 1);
sprintf(sym_name, "%s%s", prefix, suffix);
const struct Symbol *symbol = symbol_find(symbols, sym_name);
free(sym_name);
return symbol;
}
int parse_number(const char *input, int base) {
char *endptr;
int n = (int)strtol(input, &endptr, base);
if (endptr == input || *endptr || n < 0) {
error_exit("Error: Cannot parse number: \"%s\"\n", input);
}
return n;
}
void parse_symbol_value(char *input, int *restrict bank, int *restrict address) {
char *colon = strchr(input, ':');
if (!colon) {
error_exit("Error: Cannot parse bank+address: \"%s\"\n", input);
}
*colon++ = '\0';
*bank = parse_number(input, 16);
*address = parse_number(colon, 16);
}
void parse_symbols(const char *filename, struct Symbol **symbols) {
FILE *file = xfopen(filename, 'r');
struct Buffer *buffer = buffer_create(1);
enum { SYM_PRE, SYM_VALUE, SYM_SPACE, SYM_NAME } state = SYM_PRE;
int bank = 0;
int address = 0;
for (;;) {
int c = getc(file);
if (c == EOF || c == '\n' || c == '\r' || c == ';' || (state == SYM_NAME && (c == ' ' || c == '\t'))) {
if (state == SYM_NAME) {
// The symbol name has ended; append the buffered symbol
buffer_append(buffer, &(char []){'\0'});
symbol_append(symbols, buffer->data, bank, address);
}
// Skip to the next line, ignoring anything after the symbol value and name
state = SYM_PRE;
while (c != EOF && c != '\n' && c != '\r') {
c = getc(file);
}
if (c == EOF) {
break;
}
} else if (c != ' ' && c != '\t') {
if (state == SYM_PRE || state == SYM_SPACE) {
// The symbol value or name has started; buffer its contents
if (++state == SYM_NAME) {
// The symbol name has started; parse the buffered value
buffer_append(buffer, &(char []){'\0'});
parse_symbol_value(buffer->data, &bank, &address);
}
buffer->size = 0;
}
buffer_append(buffer, &c);
} else if (state == SYM_VALUE) {
// The symbol value has ended; wait to see if a name comes after it
state = SYM_SPACE;
}
}
fclose(file);
buffer_free(buffer);
}
int strfind(const char *s, const char *list[], int count) {
for (int i = 0; i < count; i++) {
if (!strcmp(s, list[i])) {
return i;
}
}
return -1;
}
#define vstrfind(s, ...) strfind(s, (const char *[]){__VA_ARGS__}, COUNTOF((const char *[]){__VA_ARGS__}))
int parse_arg_value(const char *arg, bool absolute, const struct Symbol *symbols, const char *patch_name) {
// Comparison operators for "ConditionValueB" evaluate to their particular values
int op = vstrfind(arg, "==", ">", "<", ">=", "<=", "!=", "||");
if (op >= 0) {
return op == 6 ? 0x11 : op; // "||" is 0x11
}
// Literal numbers evaluate to themselves
if (isdigit((unsigned)arg[0]) || arg[0] == '+') {
return parse_number(arg, 0);
}
// Symbols evaluate to their offset or address, plus an optional offset mod
int offset_mod = 0;
char *plus = strchr(arg, '+');
if (plus) {
offset_mod = parse_number(plus, 0);
*plus = '\0';
}
const char *sym_name = !strcmp(arg, "@") ? patch_name : arg; // "@" is the current patch label
const struct Symbol *symbol = symbol_find(symbols, sym_name);
return (absolute ? symbol->offset : symbol->address) + offset_mod;
}
void interpret_command(char *command, const struct Symbol *current_hook, const struct Symbol *symbols, struct Buffer *patches, FILE *restrict new_rom, FILE *restrict orig_rom, FILE *restrict output) {
// Strip all leading spaces and all but one trailing space
int x = 0;
for (int i = 0; command[i]; i++) {
if (!isspace((unsigned)command[i]) || (i > 0 && !isspace((unsigned)command[i - 1]))) {
command[x++] = command[i];
}
}
command[x - (x > 0 && isspace((unsigned)command[x - 1]))] = '\0';
// Count the arguments
int argc = 0;
for (const char *c = command; *c; c++) {
if (isspace((unsigned)*c)) {
argc++;
}
}
// Get the arguments
char *argv[argc]; // VLA
char *arg = command;
for (int i = 0; i < argc; i++) {
while (*arg && !isspace((unsigned)*arg)) {
arg++;
}
if (!*arg) {
break;
}
*arg++ = '\0';
argv[i] = arg;
}
// Use the arguments
if (vstrfind(command, "patch", "PATCH", "patch_", "PATCH_", "patch/", "PATCH/") >= 0) {
if (argc > 2) {
error_exit("Error: Invalid arguments for command: \"%s\"\n", command);
}
if (!current_hook) {
error_exit("Error: No current patch for command: \"%s\"\n", command);
}
int current_offset = current_hook->offset + (argc > 0 ? parse_number(argv[0], 0) : 0);
if (fseek(orig_rom, current_offset, SEEK_SET)) {
error_exit("Error: Cannot seek to \"vc_patch %s\" in the original ROM\n", current_hook->name);
}
if (fseek(new_rom, current_offset, SEEK_SET)) {
error_exit("Error: Cannot seek to \"vc_patch %s\" in the new ROM\n", current_hook->name);
}
int length;
if (argc == 2) {
length = parse_number(argv[1], 0);
} else {
const struct Symbol *current_hook_end = symbol_find_cat(symbols, current_hook->name, "_End");
length = current_hook_end->offset - current_offset;
}
buffer_append(patches, &(struct Patch){current_offset, length});
bool modified = false;
if (length == 1) {
int c = getc(new_rom);
modified = c != getc(orig_rom);
fprintf(output, isupper((unsigned)command[0]) ? "0x%02X" : "0x%02x", c);
} else {
if (command[strlen(command) - 1] != '/') {
fprintf(output, command[strlen(command) - 1] == '_' ? "a%d: " : "a%d:", length);
}
for (int i = 0; i < length; i++) {
if (i) {
putc(' ', output);
}
int c = getc(new_rom);
modified |= c != getc(orig_rom);
fprintf(output, isupper((unsigned)command[0]) ? "%02X" : "%02x", c);
}
}
if (!modified) {
fprintf(stderr, PROGRAM_NAME ": Warning: \"vc_patch %s\" doesn't alter the ROM\n", current_hook->name);
}
} else if (vstrfind(command, "dws", "DWS", "dws_", "DWS_", "dws/", "DWS/") >= 0) {
if (argc < 1) {
error_exit("Error: Invalid arguments for command: \"%s\"\n", command);
}
if (command[strlen(command) - 1] != '/') {
fprintf(output, command[strlen(command) - 1] == '_' ? "a%d: " : "a%d:", argc * 2);
}
for (int i = 0; i < argc; i++) {
int value = parse_arg_value(argv[i], false, symbols, current_hook->name);
if (value > 0xffff) {
error_exit("Error: Invalid value for \"%s\" argument: 0x%x\n", command, value);
}
if (i) {
putc(' ', output);
}
fprintf(output, isupper((unsigned)command[0]) ? "%02X %02X": "%02x %02x", value & 0xff, value >> 8);
}
} else if (vstrfind(command, "db", "DB", "db_", "DB_", "db/", "DB/") >= 0) {
if (argc != 1) {
error_exit("Error: Invalid arguments for command: \"%s\"\n", command);
}
int value = parse_arg_value(argv[0], false, symbols, current_hook->name);
if (value > 0xff) {
error_exit("Error: Invalid value for \"%s\" argument: 0x%x\n", command, value);
}
if (command[strlen(command) - 1] != '/') {
fputs(command[strlen(command) - 1] == '_' ? "a1: " : "a1:", output);
}
fprintf(output, isupper((unsigned)command[0]) ? "%02X" : "%02x", value);
} else if (vstrfind(command, "hex", "HEX", "HEx", "Hex", "heX", "hEX", "hex~", "HEX~", "HEx~", "Hex~", "heX~", "hEX~") >= 0) {
if (argc != 1 && argc != 2) {
error_exit("Error: Invalid arguments for command: \"%s\"\n", command);
}
int value = parse_arg_value(argv[0], command[strlen(command) - 1] != '~', symbols, current_hook->name);
int padding = argc > 1 ? parse_number(argv[1], 0) : 2;
if (vstrfind(command, "HEx", "HEx~") >= 0) {
fprintf(output, "0x%0*X%02x", padding - 2, value >> 8, value & 0xff);
} else if (vstrfind(command, "Hex", "Hex~") >= 0) {
fprintf(output, "0x%0*X%03x", padding - 3, value >> 12, value & 0xfff);
} else if (vstrfind(command, "heX", "heX~") >= 0) {
fprintf(output, "0x%0*x%02X", padding - 2, value >> 8, value & 0xff);
} else if (vstrfind(command, "hEX", "hEX~") >= 0) {
fprintf(output, "0x%0*x%03X", padding - 3, value >> 12, value & 0xfff);
} else {
fprintf(output, isupper((unsigned)command[0]) ? "0x%0*X" : "0x%0*x", padding, value);
}
} else {
error_exit("Error: Unknown command: \"%s\"\n", command);
}
}
void skip_to_next_line(FILE *restrict input, FILE *restrict output) {
for (int c = getc(input); c != EOF; c = getc(input)) {
putc(c, output);
if (c == '\n' || c == '\r') {
break;
}
}
}
struct Buffer *process_template(const char *template_filename, const char *patch_filename, FILE *restrict new_rom, FILE *restrict orig_rom, const struct Symbol *symbols) {
FILE *input = xfopen(template_filename, 'r');
FILE *output = xfopen(patch_filename, 'w');
struct Buffer *patches = buffer_create(sizeof(struct Patch));
struct Buffer *buffer = buffer_create(1);
// The ROM checksum will always differ
buffer_append(patches, &(struct Patch){0x14e, 2});
// Fill in the template
const struct Symbol *current_hook = NULL;
for (int c = getc(input); c != EOF; c = getc(input)) {
switch (c) {
case ';':
// ";" comments until the end of the line
putc(c, output);
skip_to_next_line(input, output);
break;
case '{':
// "{...}" is a template command; buffer its contents
buffer->size = 0;
for (c = getc(input); c != EOF && c != '}'; c = getc(input)) {
buffer_append(buffer, &c);
}
buffer_append(buffer, &(char []){'\0'});
// Interpret the command in the context of the current patch
interpret_command(buffer->data, current_hook, symbols, patches, new_rom, orig_rom, output);
break;
case '[':
// "[...]" is a patch label; buffer its contents
putc(c, output);
bool alternate = false;
buffer->size = 0;
for (c = getc(input); c != EOF; c = getc(input)) {
if (!alternate && c == '@') {
// "@" designates an alternate name for the ".VC_" label
alternate = true;
buffer->size = 0;
} else if (c == ']') {
putc(c, output);
break;
} else {
if (!alternate) {
putc(c, output);
if (!isalnum(c) && c != '_') {
// Convert non-identifier characters to underscores
c = '_';
}
}
buffer_append(buffer, &c);
}
}
buffer_append(buffer, &(char []){'\0'});
// The current patch should have a corresponding ".VC_" label
current_hook = symbol_find_cat(symbols, ".VC_", buffer->data);
skip_to_next_line(input, output);
break;
default:
putc(c, output);
}
}
rewind(orig_rom);
rewind(new_rom);
fclose(input);
fclose(output);
buffer_free(buffer);
return patches;
}
int compare_patch(const void *patch1, const void *patch2) {
unsigned int offset1 = ((const struct Patch *)patch1)->offset;
unsigned int offset2 = ((const struct Patch *)patch2)->offset;
return offset1 > offset2 ? 1 : offset1 < offset2 ? -1 : 0;
}
bool verify_completeness(FILE *restrict orig_rom, FILE *restrict new_rom, struct Buffer *patches) {
qsort(patches->data, patches->size, patches->item_size, compare_patch);
for (unsigned int offset = 0, index = 0; ; offset++) {
int orig_byte = getc(orig_rom);
int new_byte = getc(new_rom);
if (orig_byte == EOF || new_byte == EOF) {
return orig_byte == new_byte;
}
struct Patch *patch = &((struct Patch *)patches->data)[index];
if (index < patches->size && patch->offset == offset) {
if (fseek(orig_rom, patch->size, SEEK_CUR)) {
return false;
}
if (fseek(new_rom, patch->size, SEEK_CUR)) {
return false;
}
offset += patch->size;
index++;
} else if (orig_byte != new_byte) {
fprintf(stderr, PROGRAM_NAME ": Warning: Unpatched difference at offset: 0x%x\n", offset);
fprintf(stderr, " Original ROM value: 0x%02x\n", orig_byte);
fprintf(stderr, " Patched ROM value: 0x%02x\n", new_byte);
fprintf(stderr, " Current patch offset: 0x%06x\n", patch->offset);
return false;
}
}
}
int main(int argc, char *argv[]) {
if (argc != 7) {
usage_exit(1);
}
struct Symbol *symbols = NULL;
parse_symbols(argv[1], &symbols);
parse_symbols(argv[2], &symbols);
FILE *new_rom = xfopen(argv[3], 'r');
FILE *orig_rom = xfopen(argv[4], 'r');
struct Buffer *patches = process_template(argv[5], argv[6], new_rom, orig_rom, symbols);
if (!verify_completeness(orig_rom, new_rom, patches)) {
fprintf(stderr, PROGRAM_NAME ": Warning: Not all ROM differences are defined by \"%s\"\n", argv[6]);
}
symbol_free(symbols);
fclose(new_rom);
fclose(orig_rom);
buffer_free(patches);
return 0;
}