| 1 | /* |
| 2 | * (C) Copyright 2014, Stephen M. Cameron. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 16 | * |
| 17 | */ |
| 18 | |
| 19 | #include <stdio.h> |
| 20 | #include <stdlib.h> |
| 21 | #include <unistd.h> |
| 22 | #include <sys/types.h> |
| 23 | #include <sys/stat.h> |
| 24 | #include <fcntl.h> |
| 25 | #include <string.h> |
| 26 | #include <errno.h> |
| 27 | |
| 28 | static char *programname; |
| 29 | |
| 30 | static char *slurp_file(char *f, off_t *textsize) |
| 31 | { |
| 32 | int fd; |
| 33 | struct stat statbuf; |
| 34 | off_t bytesleft, bytesread; |
| 35 | char *fileptr = NULL; |
| 36 | char *slurped_file = NULL; |
| 37 | |
| 38 | fd = open(f, O_RDONLY); |
| 39 | if (fd < 0) { |
| 40 | fprintf(stderr, "%s: Cannot open '%s': %s\n", |
| 41 | programname, f, strerror(errno)); |
| 42 | return NULL; |
| 43 | } |
| 44 | if (fstat(fd, &statbuf) != 0) { |
| 45 | fprintf(stderr, "%s: Cannot stat '%s': %s\n", |
| 46 | programname, f, strerror(errno)); |
| 47 | close(fd); |
| 48 | return NULL; |
| 49 | } |
| 50 | bytesleft = statbuf.st_size; |
| 51 | slurped_file = malloc(bytesleft + 1); |
| 52 | fileptr = slurped_file; |
| 53 | if (!slurped_file) { |
| 54 | fprintf(stderr, "%s: malloc returned NULL, out of memory\n", |
| 55 | programname); |
| 56 | goto bail_out; |
| 57 | } |
| 58 | memset(slurped_file, 0, bytesleft + 1); |
| 59 | do { |
| 60 | bytesread = read(fd, fileptr, bytesleft); |
| 61 | if (bytesread < 0 && errno == EAGAIN) |
| 62 | continue; |
| 63 | if (bytesread < 0) { |
| 64 | fprintf(stderr, "%s: error reading '%s: %s'\n", |
| 65 | programname, f, strerror(errno)); |
| 66 | goto bail_out; |
| 67 | } |
| 68 | if (bytesread == 0) { |
| 69 | fprintf(stderr, "%s: unexpected EOF in %s\n", |
| 70 | programname, f); |
| 71 | goto bail_out; |
| 72 | } |
| 73 | fileptr += bytesread; |
| 74 | bytesleft -= bytesread; |
| 75 | } while (bytesleft > 0); |
| 76 | |
| 77 | *textsize = statbuf.st_size; |
| 78 | |
| 79 | close(fd); |
| 80 | return slurped_file; |
| 81 | |
| 82 | bail_out: |
| 83 | if (slurped_file) |
| 84 | free(slurped_file); |
| 85 | close(fd); |
| 86 | return NULL; |
| 87 | } |
| 88 | |
| 89 | static int detect_buggy_yacc(char *text) |
| 90 | { |
| 91 | char *x; |
| 92 | |
| 93 | x = strstr(text, " #line "); |
| 94 | if (!x) |
| 95 | return 0; |
| 96 | return 1; |
| 97 | } |
| 98 | |
| 99 | static void fixup_buggy_yacc_file(char *f) |
| 100 | { |
| 101 | char *slurped_file, *x; |
| 102 | off_t textsize; |
| 103 | char *newname; |
| 104 | int fd; |
| 105 | off_t bytesleft, byteswritten; |
| 106 | |
| 107 | newname = alloca(strlen(f) + 10); |
| 108 | strcpy(newname, "broken-"); |
| 109 | strcat(newname, f); |
| 110 | |
| 111 | slurped_file = slurp_file(f, &textsize); |
| 112 | if (!slurped_file) |
| 113 | return; |
| 114 | if (!detect_buggy_yacc(slurped_file)) |
| 115 | return; |
| 116 | |
| 117 | x = slurped_file; |
| 118 | |
| 119 | |
| 120 | /* |
| 121 | * Fixup the '#line' directives which yacc botched. |
| 122 | * Note: this is vulnerable to false positives, but |
| 123 | * since this program is just a hack to make this particular |
| 124 | * program work, it is sufficient for our purposes. |
| 125 | * regexp could make this better, but the real fix needs |
| 126 | * to be made in yacc/bison. |
| 127 | */ |
| 128 | while ((x = strstr(x, " #line ")) != NULL) { |
| 129 | *x = '\n'; |
| 130 | } |
| 131 | |
| 132 | if (rename(f, newname) != 0) { |
| 133 | fprintf(stderr, "%s: Failed to rename '%s' to '%s': %s\n", |
| 134 | programname, f, newname, strerror(errno)); |
| 135 | return; |
| 136 | } |
| 137 | fd = open(f, O_CREAT | O_TRUNC | O_RDWR, 0644); |
| 138 | if (fd < 0) { |
| 139 | fprintf(stderr, "%s: failed to create '%s': %s\n", |
| 140 | programname, f, strerror(errno)); |
| 141 | return; |
| 142 | } |
| 143 | |
| 144 | bytesleft = textsize; |
| 145 | x = slurped_file; |
| 146 | do { |
| 147 | byteswritten = write(fd, x, bytesleft); |
| 148 | if (byteswritten < 0) { |
| 149 | fprintf(stderr, "%s: Error writing '%s': %s\n", |
| 150 | programname, f, strerror(errno)); |
| 151 | return; |
| 152 | } |
| 153 | if (byteswritten == 0 && errno == EINTR) |
| 154 | continue; |
| 155 | x += byteswritten; |
| 156 | bytesleft -= byteswritten; |
| 157 | } while (bytesleft > 0); |
| 158 | close(fd); |
| 159 | } |
| 160 | |
| 161 | int main(int argc, char *argv[]) |
| 162 | { |
| 163 | int i; |
| 164 | |
| 165 | programname = argv[0]; |
| 166 | |
| 167 | for (i = 1; i < argc; i++) |
| 168 | fixup_buggy_yacc_file(argv[i]); |
| 169 | return 0; |
| 170 | } |