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- /* bake.c - Ever burned a cake?
- * Copyright 2023 Emil Williams
- *
- * Licensed under the GNU Public License version 3 only, see LICENSE.
- *
- * @BAKE cc -std=c89 -O2 -I. $@ -o $* $+ # @STOP
- */
-
- #define _POSIX_C_SOURCE 200809L
-
- #include <assert.h>
- #include <ctype.h>
- #include <errno.h>
- #include <fcntl.h>
- #include <locale.h>
- #include <stdarg.h>
- #include <stddef.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/mman.h>
- #include <sys/stat.h>
- #include <unistd.h>
-
- #include "config.h"
-
- #define HELP \
- BOLD "[option] target-file" RESET " [" GREEN "arguments" RESET " ...]\n" \
- "Use the format `" BOLD "@BAKE" RESET " cmd ...' within the target-file, this will execute the\n" \
- "rest of line, or if found within the file, until the " BOLD "@STOP" RESET " marker.\n" \
-
- #define DESC \
- "Options [Must always be first]\n" \
- "\t" DIM "-h --help" RESET", " BOLD "-n --dry-run\n" RESET \
- "Expansions\n" \
- "\t" YELLOW "$@" RESET " returns target-file (abc.x.txt)\n" \
- "\t" YELLOW "$*" RESET " returns target-file without suffix (^-> abc.x)\n" \
- "\t" YELLOW "$+" RESET " returns " GREEN "arguments" RESET "\n"
-
- typedef struct {
- size_t len;
- char * buf;
- } string_t;
-
- const static string_t START = { 5, "@BAKE" };
- const static string_t STOP = { 5, "@STOP" };
-
- /*** Utility functions ***/
-
- static void
- swap(char * a, char * b) {
- *a ^= *b;
- *b ^= *a;
- *a ^= *b;
- }
-
- static char *
- find(string_t x, char * buf, char * end) {
- for (; (buf < end) && x.len < (size_t)(end - buf); ++buf) {
- if (!strncmp(buf, x.buf, x.len))
- { return buf; }
- }
- return NULL;
- }
-
- static char *
- insert(char * new, size_t len, char * str, size_t slen, size_t offset, size_t shift) {
- size_t max;
- max = (slen + 1 - offset - shift);
- memmove(str + offset + len, str + offset + shift, max);
- memcpy(str + offset, new, len);
- return str;
- }
-
- /*** g_short, g_all Functions ***/
-
- #define GLOBALS_COUNT 3
-
- static char * globals[GLOBALS_COUNT];
-
- #define g_filename globals[0]
- #define g_short globals[1]
- #define g_all globals[2]
-
- /* doing a ? strlen(a) : "" really bothered me and this could be optimized out */
- static size_t *
- get_globals_length(void) {
- static size_t len[GLOBALS_COUNT];
- size_t i;
- for (i = 0; i < GLOBALS_COUNT; ++i) {
- len[i] = strlen(globals[i]);
- }
- return len;
- }
-
- static char *
- shorten(char * fn) {
- size_t i, last = 0, len;
- char * sh;
- len = strlen(fn);
- sh = malloc(len + 1);
- if (!sh) { return NULL; }
- for (i = 0; i < len; ++i) {
- if (fn[i] == '.') { last = i; }
- }
- last = last ? last : i;
- strncpy(sh, fn, last);
- sh[last] = '\0';
- return sh ? sh : calloc(1,1);
- }
-
- static char *
- all_args(size_t argc, char ** argv) {
- char * all = NULL;
- if (argc > 2) {
- size_t i, len = argc;
-
- for (i = 2; i < argc; ++i)
- { len += strlen(argv[i]); }
-
- all = malloc(len + 1);
- if (!all) { return NULL; }
-
- all[len] = '\0';
- for (len = 0, i = 2; i < argc; ++i) {
- strcpy(all + len, argv[i]);
- len += strlen(argv[i]) + 1;
- if (i + 1 < argc) { all[len - 1] = ' '; }
- }
- }
- return all ? all : calloc(1,1);
- }
-
- /*** Map ***/
-
- typedef struct {
- char * str;
- size_t len;
- } map_t;
-
- static map_t
- map(char * fn) {
- struct stat s;
- int fd;
- map_t m = (map_t) {0};
- fd = open(fn, O_RDONLY);
- if (fd != -1) {
- if (!fstat(fd,&s)
- && s.st_mode & S_IFREG
- && s.st_size) {
- m.len = (size_t) s.st_size;
- m.str = (char *) mmap(NULL, m.len, PROT_READ, MAP_SHARED, fd, 0);
- }
- close(fd);
- }
- return m;
- }
-
- /*** Important Functions ***/
-
- static char *
- find_region(map_t m, size_t * retlen) {
- extern char * strndup(const char * s, size_t n); /* for splint */
- char * buf = NULL, * start, * stop;
-
- start = find(START, m.str, m.str + m.len);
-
- if (start) {
- start += START.len;
-
- #ifdef REQUIRE_SPACE
- if (!isspace(*start)) {
- fprintf(stderr, RED "%s" RESET ": Found start without suffix spacing.\n", g_filename);
- return buf;
- }
- #endif /* REQUIRE_SPACE */
-
- stop = find(STOP, start, start + m.len - (start - m.str));
-
- if (!stop) {
- stop = start;
- while (*stop && *stop != '\n') {
- if (stop[0] == '\\'
- && stop[1] == '\n') { stop += 2; }
- ++stop;
- }
- }
-
- if (stop)
- {
- *retlen = (size_t) (stop - m.str) - (start - m.str);
- buf = strndup(start, *retlen);
- }
- }
- return buf;
- }
-
- static int
- root(char ** rootp) {
- char x[1] = {'\0'};
- char * root = *rootp;
- size_t len = strlen(root);
- int ret;
-
- while (len && root[len] != '/')
- { --len; }
-
- if (!len) { return 0; }
-
- swap(root + len, x);
- ret = chdir(root);
- swap(root + len, x);
-
- *rootp += len + 1;
- return ret;
- }
-
- #define ARRLEN(x) (sizeof(x) / sizeof(x[0]))
-
- static char *
- expand(char * buf, size_t len) {
- enum {
- MACRO_FILENAME = 0,
- MACRO_SHORT = 1,
- MACRO_ARGS = 2,
- };
-
- char *macro[] = {
- [MACRO_FILENAME] = "$@",
- [MACRO_SHORT ] = "$*",
- [MACRO_ARGS ] = "$+",
- };
-
- size_t macro_length[] = {
- [MACRO_FILENAME] = 2,
- [MACRO_SHORT ] = 2,
- [MACRO_ARGS ] = 2,
- };
-
- size_t * globals_length = get_globals_length();
-
- char * ptr;
- size_t i, f;
-
- {
- size_t max = len + 1;
- for (i = 0; i < len; ++i) {
- for (f = 0; f < ARRLEN(macro); ++f) {
- if (!strncmp(buf + i, macro[f], macro_length[f])) {
- max += globals_length[f];
- }
- }
- }
- buf = realloc(buf, max + 10);
- len = max - 1;
- }
- for (i = 0; i < len; ++i) {
- for (f = 0; f < ARRLEN(macro); ++f) {
- if (!strncmp(buf + i, macro[f], macro_length[f])) {
- buf = insert(globals[f], globals_length[f], buf, len, i, 2);
- }
- }
- }
- return buf;
- }
-
- /* Strips all prefixing and leading whitespace.
- * Except if the last character beforehand is a newline. */
- static size_t
- strip(char * buf) {
- size_t i = strlen(buf);
-
- if (!i)
- { return 0; }
-
- while (isspace(buf[i - 1]))
- { --i; }
-
- buf[i] = '\0';
- for (i = 0; isspace(buf[i]); ++i);
-
- return i - (buf[i - 1] == '\n');
- }
-
- static int
- run(char * buf) {
- fputs(GREEN "output" RESET ":\n", stderr);
- return system(buf);
- }
-
- int
- main(int argc, char ** argv) {
- int ret = 0;
- char * buf = NULL;
- size_t len;
-
- if (argc < 2
- || !strcmp(argv[1], "-h")
- || !strcmp(argv[1], "--help"))
- { goto help; }
-
- g_filename = argv[1];
-
- if (!strcmp(argv[1], "-n")
- || !strcmp(argv[1], "--dry-run")) {
- if (argc > 2) { ret = 1; g_filename = argv[2]; }
- else { goto help; }
- }
-
- { map_t m = map(g_filename);
- if (m.str) {
- buf = find_region(m, &len);
- munmap(m.str, m.len);
- }
- }
-
- if (!buf) {
- if (errno)
- { fprintf(stderr, BOLD RED "%s" RESET ": %s\n", g_filename, strerror(errno)); }
- else
- { fprintf(stderr, BOLD RED "%s" RESET ": File unrecognized.\n", g_filename); }
- return 1;
- }
-
- g_all = all_args((size_t) argc, argv);
- g_short = shorten(g_filename);
- root(&g_filename);
- buf = expand(buf, len);
- free(g_short); free(g_all);
- if (!buf) { return 1; }
-
- fprintf(stderr, GREEN "%s" RESET ": %s\n", argv[0], buf + strip(buf));
- ret = ret ? 0 : run(buf);
- if (ret)
- { fprintf(stderr, RED "result" RESET ": " BOLD "%d\n" RESET, ret); }
-
- free(buf);
- return ret;
- help:
- fprintf(stderr, YELLOW "%s" RESET ": %s", argv[0], HELP DESC);
- return 1;
- }
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