1 /* Read, sort and compare two directories. Used for GNU DIFF. 2 3 Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006-2007, 4 2009-2010 Free Software Foundation, Inc. 5 6 This file is part of GNU DIFF. 7 8 This program is free software: you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation, either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 20 21 #include "diff.h" 22 #include <error.h> 23 #include <exclude.h> 24 #include <setjmp.h> 25 #include <xalloc.h> 26 27 /* Read the directory named by DIR and store into DIRDATA a sorted vector 28 of filenames for its contents. DIR->desc == -1 means this directory is 29 known to be nonexistent, so set DIRDATA to an empty vector. 30 Return -1 (setting errno) if error, 0 otherwise. */ 31 32 struct dirdata 33 { 34 size_t nnames; /* Number of names. */ 35 char const **names; /* Sorted names of files in dir, followed by 0. */ 36 char *data; /* Allocated storage for file names. */ 37 }; 38 39 /* Whether file names in directories should be compared with 40 locale-specific sorting. */ 41 static bool locale_specific_sorting; 42 43 /* Where to go if locale-specific sorting fails. */ 44 static jmp_buf failed_locale_specific_sorting; 45 46 static bool dir_loop (struct comparison const *, int); 47 static int compare_names_for_qsort (void const *, void const *); 48 49 50 /* Read a directory and get its vector of names. */ 51 52 static bool 53 dir_read (struct file_data const *dir, struct dirdata *dirdata) 54 { 55 register struct dirent *next; 56 register size_t i; 57 58 /* Address of block containing the files that are described. */ 59 char const **names; 60 61 /* Number of files in directory. */ 62 size_t nnames; 63 64 /* Allocated and used storage for file name data. */ 65 char *data; 66 size_t data_alloc, data_used; 67 68 dirdata->names = 0; 69 dirdata->data = 0; 70 nnames = 0; 71 data = 0; 72 73 if (dir->desc != -1) 74 { 75 /* Open the directory and check for errors. */ 76 register DIR *reading = opendir (dir->name); 77 if (!reading) 78 return false; 79 80 /* Initialize the table of filenames. */ 81 82 data_alloc = 512; 83 data_used = 0; 84 dirdata->data = data = xmalloc (data_alloc); 85 86 /* Read the directory entries, and insert the subfiles 87 into the `data' table. */ 88 89 while ((errno = 0, (next = readdir (reading)) != 0)) 90 { 91 char *d_name = next->d_name; 92 size_t d_size = _D_EXACT_NAMLEN (next) + 1; 93 94 /* Ignore "." and "..". */ 95 if (d_name[0] == '.' 96 && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0))) 97 continue; 98 99 if (excluded_file_name (excluded, d_name)) 100 continue; 101 102 while (data_alloc < data_used + d_size) 103 { 104 if (PTRDIFF_MAX / 2 <= data_alloc) 105 xalloc_die (); 106 dirdata->data = data = xrealloc (data, data_alloc *= 2); 107 } 108 109 memcpy (data + data_used, d_name, d_size); 110 data_used += d_size; 111 nnames++; 112 } 113 if (errno) 114 { 115 int e = errno; 116 closedir (reading); 117 errno = e; 118 return false; 119 } 120 #if CLOSEDIR_VOID 121 closedir (reading); 122 #else 123 if (closedir (reading) != 0) 124 return false; 125 #endif 126 } 127 128 /* Create the `names' table from the `data' table. */ 129 if (PTRDIFF_MAX / sizeof *names - 1 <= nnames) 130 xalloc_die (); 131 dirdata->names = names = xmalloc ((nnames + 1) * sizeof *names); 132 dirdata->nnames = nnames; 133 for (i = 0; i < nnames; i++) 134 { 135 names[i] = data; 136 data += strlen (data) + 1; 137 } 138 names[nnames] = 0; 139 return true; 140 } 141 142 /* Compare file names, returning a value compatible with strcmp. */ 143 144 static int 145 compare_names (char const *name1, char const *name2) 146 { 147 if (locale_specific_sorting) 148 { 149 int r; 150 errno = 0; 151 if (ignore_file_name_case) 152 r = strcasecoll (name1, name2); 153 else 154 r = strcoll (name1, name2); 155 if (errno) 156 { 157 error (0, errno, _("cannot compare file names `%s' and `%s'"), 158 name1, name2); 159 longjmp (failed_locale_specific_sorting, 1); 160 } 161 return r; 162 } 163 164 return (ignore_file_name_case 165 ? strcasecmp (name1, name2) 166 : file_name_cmp (name1, name2)); 167 } 168 169 /* A wrapper for compare_names suitable as an argument for qsort. */ 170 171 static int 172 compare_names_for_qsort (void const *file1, void const *file2) 173 { 174 char const *const *f1 = file1; 175 char const *const *f2 = file2; 176 return compare_names (*f1, *f2); 177 } 178 179 /* Compare the contents of two directories named in CMP. 180 This is a top-level routine; it does everything necessary for diff 181 on two directories. 182 183 CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist, 184 but pretend it is empty. Likewise for CMP->file[1]. 185 186 HANDLE_FILE is a caller-provided subroutine called to handle each file. 187 It gets three operands: CMP, name of file in dir 0, name of file in dir 1. 188 These names are relative to the original working directory. 189 190 For a file that appears in only one of the dirs, one of the name-args 191 to HANDLE_FILE is zero. 192 193 Returns the maximum of all the values returned by HANDLE_FILE, 194 or EXIT_TROUBLE if trouble is encountered in opening files. */ 195 196 int 197 diff_dirs (struct comparison const *cmp, 198 int (*handle_file) (struct comparison const *, 199 char const *, char const *)) 200 { 201 struct dirdata dirdata[2]; 202 int volatile val = EXIT_SUCCESS; 203 int i; 204 205 if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0)) 206 && (cmp->file[1].desc == -1 || dir_loop (cmp, 1))) 207 { 208 error (0, 0, _("%s: recursive directory loop"), 209 cmp->file[cmp->file[0].desc == -1].name); 210 return EXIT_TROUBLE; 211 } 212 213 /* Get contents of both dirs. */ 214 for (i = 0; i < 2; i++) 215 if (! dir_read (&cmp->file[i], &dirdata[i])) 216 { 217 perror_with_name (cmp->file[i].name); 218 val = EXIT_TROUBLE; 219 } 220 221 if (val == EXIT_SUCCESS) 222 { 223 char const **volatile names[2]; 224 names[0] = dirdata[0].names; 225 names[1] = dirdata[1].names; 226 227 /* Use locale-specific sorting if possible, else native byte order. */ 228 locale_specific_sorting = true; 229 if (setjmp (failed_locale_specific_sorting)) 230 locale_specific_sorting = false; 231 232 /* Sort the directories. */ 233 for (i = 0; i < 2; i++) 234 qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names, 235 compare_names_for_qsort); 236 237 /* If `-S name' was given, and this is the topmost level of comparison, 238 ignore all file names less than the specified starting name. */ 239 240 if (starting_file && ! cmp->parent) 241 { 242 while (*names[0] && compare_names (*names[0], starting_file) < 0) 243 names[0]++; 244 while (*names[1] && compare_names (*names[1], starting_file) < 0) 245 names[1]++; 246 } 247 248 /* Loop while files remain in one or both dirs. */ 249 while (*names[0] || *names[1]) 250 { 251 /* Compare next name in dir 0 with next name in dir 1. 252 At the end of a dir, 253 pretend the "next name" in that dir is very large. */ 254 int nameorder = (!*names[0] ? 1 : !*names[1] ? -1 255 : compare_names (*names[0], *names[1])); 256 int v1 = (*handle_file) (cmp, 257 0 < nameorder ? 0 : *names[0]++, 258 nameorder < 0 ? 0 : *names[1]++); 259 if (val < v1) 260 val = v1; 261 } 262 } 263 264 for (i = 0; i < 2; i++) 265 { 266 free (dirdata[i].names); 267 free (dirdata[i].data); 268 } 269 270 return val; 271 } 272 273 /* Return nonzero if CMP is looping recursively in argument I. */ 274 275 static bool 276 dir_loop (struct comparison const *cmp, int i) 277 { 278 struct comparison const *p = cmp; 279 while ((p = p->parent)) 280 if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat)) 281 return true; 282 return false; 283 } 284