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- /* baked.c - Ever burned a cake?
- *
- * Copyright 2023 Emil Williams
- *
- * baked is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 3
- * as published by the Free Software Foundation.
- *
- * You should have received a copy of the GNU General Public License
- * version 3 along with this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.en.html>.
- *
- * This program is independent of language, it simply expects the notation as listed below,
- *
- * EXEC:cc baked.c -o baked -std=gnu99 -O2 -Wall -Wextra -Wpedantic -pipe $CFLAGS:STOP
- *
- * Which will run, and in this case, result in this program compiling itself.
- *
- * Another (functional) example:
- EXEC:
- CFLAGS='-std=gnu99 -O2 -Wall -Wextra -Wpedantic -pipe'
- cc baked.c -o baked $CFLAGS # baked
- :STOP
- *
- * See install.sh for another example coded into a different language.
- * It is possible to override environmental variables, as in install.sh,
- * you can then have some dynamism.
- *
- * Realistically, any traditional shell script could be composed in this
- * fashion, and be embedded in any file. However, some programming languages
- * may not have multiline comments, so you may be restricted to a single line.
- *
- * with the flag CFLAGS='-DSHAKE_COMPAT' Shake compatibility will be enabled,
- * @COMPILECMD cc baked.c -o baked -std=gnu99 -O2 -Wall -Wextra -Wpedantic -pipe $CFLAGS # SHAKE_COMPAT enabled
- *
- * TODO
- *
- * 1. replace asserts with proper checks (maybe longjmp, however
- * this might be costly, and might not satify -fanalyzer)
- * 2. somehow convince the compiler to do NULL checks before g_...
- * so that allocs can be minimized even further (maybe volatile)
- */
-
- #include <assert.h>
- #include <errno.h>
- #include <stdarg.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <unistd.h>
- #include <sys/stat.h>
-
- #ifndef SHAKE_COMPAT
- # define HELP \
- "target-file\n" \
- "Use the format `EXEC:command ...:STOP' within the target-file\n"
- # define START "EXEC:"
- # define STOP ":STOP"
- #else
- # define HELP \
- "target-file\n" \
- "Use the format `@COMPILECMD command ...\n' within the target-file\n"
- # define START "@COMPILECMD"
- # define STOP "\n"
- #endif
-
- #define DESC \
- "\t$@ returns target-file value\n" \
- "\t$* returns target-file without extension\n" \
- "\t$+ returns arguments\n"
-
- #define die(fmt, ...) do { _die(fmt, ##__VA_ARGS__); goto stop; } while (0)
-
- static const char * argv0;
- static char * g_filename = NULL, * g_sh = NULL, * g_all = NULL;
-
- static void
- _die(const char * fmt,
- ...)
- {
- va_list ap;
- assert(fmt);
- fprintf(stderr, "%s: ", argv0);
- va_start(ap, fmt);
- vfprintf(stderr, fmt, ap);
- va_end(ap);
- if (fmt[0] &&
- fmt[strlen(fmt)-1] == ':')
- {
- fputc(' ', stderr);
- perror(NULL);
- }
- else
- { fputc('\n', stderr); }
- }
-
- static int
- exists(const char * fn)
- {
- struct stat buf;
- if (!stat(fn,&buf) &&
- buf.st_mode & S_IFREG)
- { return 1; }
- return 0;
- }
-
- static char *
- load(const char * fn)
- {
- size_t len;
- char * buf;
- FILE * fp = fopen(fn, "rb");
- if (fp)
- {
- fseek(fp, 0, SEEK_END);
- len = ftell(fp);
- rewind(fp);
- buf = malloc(len + 1);
- if (fread(buf, 1, len, fp) > strlen(STOP) + strlen(START))
- {
- buf[len] = '\0';
- fclose(fp);
- return buf;
- }
- fclose(fp);
- free(buf);
- }
- return NULL;
- }
-
- static void
- swap(char * a, char * b)
- {
- *a ^= *b;
- *b ^= *a;
- *a ^= *b;
- }
-
- static int
- root(char * root)
- {
- char x[1] = "\0";
- int ret;
- size_t len = strlen(root);
- while (len && root[len] != '/')
- { --len; }
- if (!len)
- { return 0; }
- swap(root + len, x);
- ret = chdir(root);
- swap(root + len, x);
- return ret;
- }
-
- static char *
- insert(const char * new, char * str, size_t offset, size_t shift)
- {
- size_t len = strlen(new);
- size_t max = strlen(str) + 1;
- /* fprintf(stderr, "params '%s' '%s' %ld %ld\n", new, str, offset, shift); */
- str = realloc(str, max + len);
- assert(str);
- memmove(str + offset + len, str + offset + shift, max - offset - shift);
- memcpy(str + offset, new, len);
- return str;
- }
-
- static char *
- find(char * buf, const char * token)
- {
- size_t len = strlen(token);
- const char * stop = buf + strlen(buf);
- do if (!strncmp(buf,token,len))
- { return buf + len; }
- while (buf < stop && ++buf);
- return NULL;
- }
-
- static char *
- expand(char * buf, size_t len)
- {
- size_t i = 0;
- char * str = "";
- ++len;
- assert(buf);
- for (i = 0; i < len; ++i)
- {
- if (buf[i] == '\\')
- { i+=2; continue; }
- if (buf[i] == '$')
- {
- switch (buf[++i])
- {
- case '@': /* replace $@ with g_filename */
- str = g_filename;
- break;
- case '*': /* replace $* with short nm */
- str = g_sh;
- break;
- case '+': /* replace $+ with all args */
- str = g_all;
- break;
- default: continue;
- }
- buf = insert(str, buf, i - 1, 2);
- len = strlen(buf);
- }
- }
- return buf;
- }
-
- static void
- init(char ** argv, int argc)
- {
- size_t i, len;
-
- /* g_filename */
- g_filename = malloc(strlen(argv[1]) + 1);
- strcpy(g_filename, argv[1]);
-
- /* sh */
- { size_t last = 0;
- len = strlen(argv[1]); /* co-opting len */
- g_sh = malloc(len + 1);
- for (i = 0; i < len; ++i)
- {
- if (argv[1][i] == '.')
- { last = i; }
- }
- last = last ? last : i;
- strncpy(g_sh, argv[1], last);
- g_sh[last] = '\0';
- } /* EOL last */
- /* all */
- if (argc > 2)
- {
- len = 0;
- i = 2;
- while (i < (size_t) argc)
- {
- len += strlen(argv[i]);
- ++i;
- }
- g_all = malloc(len + 1);
- g_all[len] = '\0';
- len = 0;
- i = 2;
- while (i < (size_t) argc)
- {
- strcpy(g_all + len, argv[i]);
- len += strlen(argv[i]);
- ++i;
- }
- }
- }
-
- int
- main(int argc, char ** argv)
- {
- int ret = 0;
- char * buf = NULL;
- { size_t len;
- { char * start, * stop;
-
- argv0 = argv[0];
-
- if (argc < 2)
- { die(HELP); }
-
- if (!exists(argv[1]))
- { die("cannot access '%s':", argv[1]); }
-
- if (!(buf = load(argv[1]))
- || root(argv[1]))
- { die(errno ? NULL : "File too short"); }
-
- if (!(start = find(buf, START))
- || !(stop = find(start, STOP)))
- { die("No usable format located in '%s'", argv[1]); }
- init(argv, argc);
- len = stop - start - strlen(STOP);
- memmove(buf, start, len);
- } /* EOL start stop*/
- buf = realloc(buf, len + 1);
- buf[len] = '\0';
- fprintf(stderr, "Exec: %s\nOutput:\n", buf);
- buf = expand(buf, len);
- } /* EOL len */
- fprintf(stderr, "Result: %d\n", (ret = system(buf)));
-
- stop:
- free(g_filename);
- free(g_sh);
- free(g_all);
- free(buf);
- return ret;
- }
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