make_shim.c

#include <stdio.h>
#include <getopt.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

struct Section {
    unsigned short end;
    bool invalid;
    char * name;
    bool banked;
};

typedef struct Section section_t;

size_t strrspn(const char *s1, const char *s2) {
    const char * _s1 = s1;
    const char * _s2;

    while (*_s1++);
    _s1--;
    while (_s1 > s1) {
        for (_s2 = s2; *_s2; _s2++) {
            if (_s1[-1] == *_s2) {
                break;
            }
        }
        if (*_s2 == 0)
            break;
        _s1--;
    }

    return _s1 - s1;
}

size_t strrcspn(const char *s1, const char *s2) {
    const char * _s1 = s1;
    const char * _s2;

    while (*_s1++);
    _s1--;
    while (_s1 > s1) {
        for (_s2 = s2; *_s2; _s2++) {
            if (_s1[-1] == *_s2)
                break;
        }
        if (*_s2)
            break;
        _s1--;
    }

    return _s1 - s1;
}

int main(int argc, char * argv[]) {
    int ch;
    size_t lsize = 0;
    char * line = NULL;

    section_t section_list[] = {
        {0x4000, false, "ROM0", false},
        {0x8000, false, "ROMX", true},
        {0xA000, false, "VRAM", true},
        {0xC000, false, "SRAM", true},
        {0xD000, false, "WRAM0", false},
        {0xE000, false, "WRAMX", true},
        {0xFE00, true, "Echo RAM", false},
        {0xFEA0, false, "OAM", false},
        {0xFF80, true, "FEXX / IO", false},
        {0xFFFF, false, "HRAM", false},
        {}
    };

    while ((ch = getopt(argc, argv, "wdt")) != -1) {
        switch (ch) {
            case 'w':
            case 'd':
                section_list[4].end = 0xE000;
                break;
            case 't':
                section_list[0].end = 0x8000;
                break;
        }
    }

    for (int arg_idx = optind; arg_idx < argc; arg_idx++) {
        FILE * file = fopen(argv[arg_idx], "r");
        if (file == NULL) {
            perror("file io");
            free(line);
            return 1;
        }
        while (getline(&line, &lsize, file) > 0) {
            unsigned short bank = 0;
            unsigned short pointer = 0;
            char * symbol = NULL;
            char * end;
            char * addr_p;

            // line = line.split(";")[0].strip()
            line += strspn(line, " \t\n");
            end = strchr(line, ';');
            if (end) *end = 0;
            line[strrspn(line, " \t\n")] = 0;
            if (!*line)
                continue;

            // Get the bank, address, and symbol
            end = line + strcspn(line, " \t\n");
            symbol = end + strspn(end, " \t\n");
            if (!*symbol) {
                perror("parse");
                free(line);
                fclose(file);
                return 1;
            }
            *end = 0;
            addr_p = strchr(line, ':');
            if (!addr_p) {
                perror("parse");
                free(line);
                fclose(file);
                return 1;
            }
            *addr_p++ = 0;
            pointer = strtoul(addr_p, &end, 16);
            if (pointer == 0 && end == addr_p) {
                perror("parse");
                free(line);
                fclose(file);
                return 1;
            }
            bank = strtoul(line, &end, 16);
            if (bank == 0 && end == line) {
                perror("parse");
                free(line);
                fclose(file);
                return 1;
            }

            // Main loop
            const char * section = NULL;
            section_t * section_type;

            for (section_type = section_list; section_type->end; section_type++) {
                if (pointer < section_type->end) {
                    if (section_type->invalid) {
                        fprintf(stderr, "Warning: cannot shim '%s' in section type '%s'\n", symbol, section_type->name);
                    } else {
                        section = section_type->name;
                        if (!section_type->banked)
                            bank = 0;
                    }
                    break;
                }
            }

            if (section == NULL)
                // Found section, but cannot shim it
                continue;

            printf("SECTION \"Shim for %s\", %s[$%04X]", symbol, section, pointer);
            if (bank)
                printf(", BANK[$%04X]", bank);
            printf("\n%s::\n\n", symbol);
            fflush(stdout);
        }
        fclose(file);
    }
    free(line);
    return 0;
}