eddy_em

Хоть true inline — и хорошо, но больно уж неудобно пользоваться и есть шанс, что сгенерировав код, затрешь свои изменения. Поэтому я решил функции делать "слабыми синонимами": __attribute__ ((weak, alias ("__f1"))) на функцию __f1, которая просто возвращает 1. Функцию parsecmd упростил (теперь она не выкидывает пробелы, чтобы разработчик мог сложные команды типа "set ip" или "set param" отправить, вычленять команду из строки ввода — задача разработчика).
Заодно добавил проверку на совпадение имен функций для разных команд (скажем, "sim-key", "sim_key", "sim key" и "sim'key" дадут одну и ту же функцию fn_sim_key). В таком случае утилита выдаст матюк:

Have two similar function names for 'sim key' and 'sim-key': 'fn_sim_key'
Have two similar function names for 'sim-key' and 'sim'key': 'fn_sim_key'
Have two similar function names for 'sim'key' and 'sim_key': 'fn_sim_key'
Can't generate code when names of some functions matches

И благополучно отвалится.

Код на гитхабе. Исходник хешегенератора:

/*
 * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <string.h>
#include <usefull_macros.h>
#include <ctype.h>

#define ALLOCSZ     (5000)

typedef struct{
    char *dict;
    char *headerfile;
    char *sourcefile;
    int genfunc;
} glob_pars;

static glob_pars G = {.headerfile = "hash.h", .sourcefile = "hash.c"};
static int help = 0;
static myoption cmdlnopts[] = {
    {"help",    NO_ARGS,    NULL,   'h',    arg_int,    APTR(&help),        "show this help"},
    {"dict",    NEED_ARG,   NULL,   'd',    arg_string, APTR(&G.dict),      "dictionary file"},
    {"header",  NEED_ARG,   NULL,   'H',    arg_string, APTR(&G.headerfile),"output header filename"},
    {"source",  NEED_ARG,   NULL,   'S',    arg_string, APTR(&G.sourcefile),"output source filename"},
    {"genfunc", NO_ARGS,    NULL,   'F',    arg_int,    APTR(&G.genfunc),   "generate function bodys"},
    end_option
};
static void parse_args(int argc, char **argv){
    parseargs(&argc, &argv, cmdlnopts);
    if(help) showhelp(-1, cmdlnopts);
    if(argc > 0){
        red("Unused arguments:\n");
        for(int i = 0; i < argc; ++i)
            printf("%s ", argv[i]);
        printf("\n");
        showhelp(-1, cmdlnopts);
    }
}

#define HASHFNO (3)
// djb2 & sdbm: http://www.cse.yorku.ca/~oz/hash.html
static uint32_t djb2(const char *str){
    uint32_t hash = 5381;
    uint32_t c;
    while((c = (uint32_t)*str++))
        hash = ((hash << 7) + hash) + c;
        //hash = hash * 31 + c;
        //hash = hash * 33 + c;
    return hash;
}
static uint32_t sdbm(const char *str){
    uint32_t hash = 5381;
    uint32_t c;
    while((c = (uint32_t)*str++))
        hash = c + (hash << 6) + (hash << 16) - hash;
    return hash;
}
// jenkins: https://en.wikipedia.org/wiki/Jenkins_hash_function
static uint32_t jenkins(const char *str){
    uint32_t hash = 0, c;
    while((c = (uint32_t)*str++)){
        hash += c;
        hash += (hash << 10);
        hash ^= (hash >> 6);
    }
    hash += (hash << 3);
    hash ^= (hash >> 11);
    hash += (hash << 15);
    return hash;
}

static const char *hashsources[HASHFNO] = {
"static uint32_t hashf(const char *str){\n\
    uint32_t hash = 5381;\n\
    uint32_t c;\n\
    while((c = (uint32_t)*str++))\n\
        hash = ((hash << 7) + hash) + c;\n\
    return hash;\n\
}\n",
"static uint32_t hashf(const char *str){\n\
    uint32_t hash = 5381;\n\
    uint32_t c;\n\
    while((c = (uint32_t)*str++))\n\
        hash = c + (hash << 6) + (hash << 16) - hash;\n\
    return hash;\n\
}\n",
"static uint32_t hashf(const char *str){\n\
    uint32_t hash = 0, c;\n\
    while((c = (uint32_t)*str++)){\n\
        hash += c;\n\
        hash += (hash << 10);\n\
        hash ^= (hash >> 6);\n\
    }\n\
    hash += (hash << 3);\n\
    hash ^= (hash >> 11);\n\
    hash += (hash << 15);\n\
    return hash;\n\
}\n"
};

static uint32_t (*hash[HASHFNO])(const char *str) = {djb2, sdbm, jenkins};
static const char *hashnames[HASHFNO] = {"DJB2", "SDBM", "Jenkins"};

typedef struct{
    char str[32];       // string command
    char fname[32];     // function namee
    uint32_t hash;      // command hash
} strhash;

static int sorthashesH(const void *a, const void *b){ // sort by hash
    register uint32_t h1 = ((strhash*)a)->hash, h2 = ((strhash*)b)->hash;
    if(h1 > h2) return 1;
    else if(h1 < h2) return -1;
    return 0;
}
static int sorthashesS(const void *a, const void *b){ // sort by string
    char *s1 = ((strhash*)a)->str, *s2 = ((strhash*)b)->str;
    return strcmp(s1, s2);
}
static int sorthashesF(const void *a, const void *b){ // sort by fname
    char *s1 = ((strhash*)a)->fname, *s2 = ((strhash*)b)->fname;
    return strcmp(s1, s2);
}

static FILE *openoutp(const char *name){
    FILE *f = fopen(name, "w");
    if(!f) ERR("Can't open file %s", name);
    return f;
}

static char *macroname(const char *cmd){
    static char macro[32];
    int i = 0;
    while(i < 31 && *cmd){
        char c = *cmd++;
        if(!isalnum(c)) c = '_';
        if(islower(c)) c = toupper(c);
        macro[i++] = c;
    }
    macro[i] = 0;
    return macro;
}

static char *fnname(const char *cmd){
    static char fn[32];
    int i = 0;
    while(i < 31 && *cmd){
        char c = *cmd++;
        if(!isalpha(c)) c = '_';
        if(isupper(c)) c = tolower(c);
        fn[i++] = c;
    }
    fn[i] = 0;
    return fn;
}

static const char *fhdr =
"int parsecmd(char *cmd, char *args){\n\
    if(!cmd || !args) return 0;\n\
    uint32_t h = hashf(cmd);\n\
    switch(h){\n"
;
static const char *ffooter =
"        default: return 0;\n\
    }\n\
    return 0;\n\
}\n\n"
;
static const char *fns =
"int fn_%s(_U_ uint32_t hash,  _U_ char *args) WAL; // \"%s\" (%u)\n\n"
;
static const char *fproto = "int parsecmd(char *cmdwargs, char *args);\n\n";
static const char *sw =
"        case CMD_%s:\n\
            return fn_%s(h, args);\n\
        break;\n";
static const char *srchdr =
"#include <stdint.h>\n\
#include <stddef.h>\n\
#include \"%s\"\n\n\
#ifndef _U_\n\
#define _U_ __attribute__((__unused__))\n\
#endif\n\n\
#ifndef WAL\n\
#define WAL __attribute__ ((weak, alias (\"__f1\")))\n\
#endif\n\nint __f1(_U_ uint32_t h, _U_ char *a){return 1;}\n\n"
;

static void build(strhash *H, int hno, int hlen){
    green("Generate files for hash function '%s'\n", hashnames[hno]);
    int lmax = 1;
    for(int i = 0; i < hlen; ++i){
        int l = strlen(H[i].str);
        if(l > lmax){
            lmax = l;
        }
    }
    lmax = (lmax + 3)/4;
    lmax *= 4;
    // resort H by strings
    qsort(H, hlen, sizeof(strhash), sorthashesS);
    FILE *source = openoutp(G.sourcefile), *header = openoutp(G.headerfile);
    fprintf(source, srchdr, G.headerfile);
    if(G.genfunc){
        for(int i = 0; i < hlen; ++i){
            fprintf(source, fns, H[i].fname, H[i].str, H[i].hash);
        }
    }
    fprintf(header, "%s", fproto);
    fprintf(source, "%s\n", hashsources[hno]);
    fprintf(source, "%s", fhdr);
    for(int i = 0; i < hlen; ++i){
        char *m = macroname(H[i].str);
        fprintf(source, sw, m, H[i].fname);
        fprintf(header, "#define CMD_%-*s    (%u)\n", lmax, m, H[i].hash);
    }
    fprintf(source, "%s", ffooter);
    fclose(source);
    fclose(header);
}

int main(int argc, char **argv){
    initial_setup();
    parse_args(argc, argv);
    if(!G.dict) ERRX("point dictionary file");
    if(!G.headerfile) ERRX("point header source file");
    if(!G.sourcefile) ERRX("point c source file");
    mmapbuf *b = My_mmap(G.dict);
    if(!b) ERRX("Can't open %s", G.dict);
    char *word = b->data;
    strhash *H = MALLOC(strhash, ALLOCSZ);
    int l = ALLOCSZ, idx = 0;
    while(*word){
        if(idx >= l){
            l += ALLOCSZ;
            H = realloc(H, sizeof(strhash) * l);
            if(!H) ERR("realloc()");
        }
        while(*word && *word < 33) ++word;
        if(!*word) break;
        char *nxt = strchr(word, '\n');
        if(nxt){
            int len = nxt - word;
            if(len > 31) len = 31;
            strncpy(H[idx].str, word, len);
            H[idx].str[len] = 0;
        }else{
            snprintf(H[idx].str, 31, "%s", word);
        }
        snprintf(H[idx].fname, 31, "%s", fnname(H[idx].str));
        ++idx;
        if(!nxt) break;
        word = nxt + 1;
    }
    // test fname matches
    qsort(H, idx, sizeof(strhash), sorthashesF);
    int mflag = 0;
    int imax1 = idx - 1, hno = 0;
    for(int i = 0; i < imax1; ++i){ // test hash matches
        if(0 == strcmp(H[i].fname, H[i+1].fname)){
            mflag = 1;
            WARNX("Have two similar function names for '%s' and '%s': 'fn_%s'",
                  H[i].str, H[i+1].str, H[i].fname);
        }
    }
    if(mflag) ERRX("Can't generate code when names of some functions matches");
    for(; hno < HASHFNO; ++hno){
        for(int i = 0; i < idx; ++i)
            H[i].hash = hash[hno](H[i].str);
        qsort(H, idx, sizeof(strhash), sorthashesH);
        strhash *p = H;
        int nmatches = 0;
        for(int i = 0; i < imax1; ++i, ++p){ // test hash matches
            if(p->hash == p[1].hash) ++nmatches;
        }
        if(nmatches == 0){
            build(H, hno, idx);
            break;
        }
        WARNX("Function '%s' have %d matches", hashnames[hno], nmatches);
    }
    if(hno == HASHFNO) WARNX("Can't find proper hash function");
    FREE(H);
    My_munmap(b);
    return 0;
}

Собираем и запускаем с тестовым "словарем":

hello
world
what
put
sim key
change ip
change param
set
         clear
reset
  get
out
in

Теперь допускаются команды из нескольких слов. Если же первыми символами в строке являются недопустимые, они опускаются.
Получаем заголовочный файл:

int parsecmd(char *cmdwargs, char *args);

#define CMD_CHANGE_IP       (1920374500)
#define CMD_CHANGE_PARAM    (1673545756)
#define CMD_CLEAR           (2063720716)
#define CMD_GET             (2963126085)
#define CMD_HELLO           (3433426201)
#define CMD_IN              (89558876)
#define CMD_OUT             (2963261277)
#define CMD_PUT             (2963277918)
#define CMD_RESET           (1907803304)
#define CMD_SET             (2963325777)
#define CMD_SIM_KEY         (2773741623)
#define CMD_WHAT            (25570233)
#define CMD_WORLD           (3313868845)

и исходник:

#include <stdint.h>
#include <stddef.h>
#include "hash.h"

#ifndef _U_
#define _U_ __attribute__((__unused__))
#endif

#ifndef WAL
#define WAL __attribute__ ((weak, alias ("__f1")))
#endif

static int __f1(_U_ uint32_t h, _U_ char *a){return 1;}

int fn_change_ip(_U_ uint32_t hash,  _U_ char *args) WAL; // "change ip" (1920374500)

int fn_change_param(_U_ uint32_t hash,  _U_ char *args) WAL; // "change param" (1673545756)

int fn_clear(_U_ uint32_t hash,  _U_ char *args) WAL; // "clear" (2063720716)

int fn_get(_U_ uint32_t hash,  _U_ char *args) WAL; // "get" (2963126085)

int fn_hello(_U_ uint32_t hash,  _U_ char *args) WAL; // "hello" (3433426201)

int fn_in(_U_ uint32_t hash,  _U_ char *args) WAL; // "in" (89558876)

int fn_out(_U_ uint32_t hash,  _U_ char *args) WAL; // "out" (2963261277)

int fn_put(_U_ uint32_t hash,  _U_ char *args) WAL; // "put" (2963277918)

int fn_reset(_U_ uint32_t hash,  _U_ char *args) WAL; // "reset" (1907803304)

int fn_set(_U_ uint32_t hash,  _U_ char *args) WAL; // "set" (2963325777)

int fn_sim_key(_U_ uint32_t hash,  _U_ char *args) WAL; // "sim key" (2773741623)

int fn_what(_U_ uint32_t hash,  _U_ char *args) WAL; // "what" (25570233)

int fn_world(_U_ uint32_t hash,  _U_ char *args) WAL; // "world" (3313868845)

static uint32_t hashf(const char *str){
    uint32_t hash = 5381;
    uint32_t c;
    while((c = (uint32_t)*str++))
        hash = ((hash << 7) + hash) + c;
    return hash;
}

int parsecmd(char *cmd, char *args){
    if(!cmd || !args) return 0;
    uint32_t h = hashf(cmd);
    switch(h){
        case CMD_CHANGE_IP:
            return fn_change_ip(h, args);
        break;
        case CMD_CHANGE_PARAM:
            return fn_change_param(h, args);
        break;
        case CMD_CLEAR:
            return fn_clear(h, args);
        break;
        case CMD_GET:
            return fn_get(h, args);
        break;
        case CMD_HELLO:
            return fn_hello(h, args);
        break;
        case CMD_IN:
            return fn_in(h, args);
        break;
        case CMD_OUT:
            return fn_out(h, args);
        break;
        case CMD_PUT:
            return fn_put(h, args);
        break;
        case CMD_RESET:
            return fn_reset(h, args);
        break;
        case CMD_SET:
            return fn_set(h, args);
        break;
        case CMD_SIM_KEY:
            return fn_sim_key(h, args);
        break;
        case CMD_WHAT:
            return fn_what(h, args);
        break;
        case CMD_WORLD:
            return fn_world(h, args);
        break;
        default: return 0;
    }
    return 0;
}

Теперь уже где-то в другом месте все эти функции мы можем спокойно переопределить, скажем, так:

#include <stdio.h>
#include <string.h>
#include <stdint.h>

#include "hash.h"

int fn_hello(uint32_t hash,  char *args){
    printf("HELLO! Hash=%u, param=%s\n", hash, args);
    return 1;
}
int fn_world(uint32_t hash,  char *args){
    printf("WORLD: %u - %s\n", hash, args);
    return 1;
}

int main(int argc, char **argv){
    if(argc < 2) return 1;
    char *args = "";
    if(argc > 2) args = argv[2];
    if(!parsecmd(argv[1], args)) printf("%s not found\n", argv[1]);
    else printf("All OK\n");
    return 0;
}

И проверить:

./test hello param1
HELLO! Hash=3433426201, param=param1
All OK

./test world 
WORLD: 3313868845 - 
All OK

./test "change ip"
All OK

./test change ip
change not found

Обновление "хешегенератора"

Обновление "хешегенератора"

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