1/* Read, sort and compare two directories. Used for GNU DIFF. 2 3 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1998, 2001, 2002 4 Free Software Foundation, Inc. 5 6 This file is part of GNU DIFF. 7 8 GNU DIFF 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 2, or (at your option) 11 any later version. 12 13 GNU DIFF 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; see the file COPYING. 20 If not, write to the Free Software Foundation, 21 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 22 23#include "diff.h" 24#include <error.h> 25#include <exclude.h> 26#include <setjmp.h> 27#include <xalloc.h> 28 29/* Read the directory named by DIR and store into DIRDATA a sorted vector 30 of filenames for its contents. DIR->desc == -1 means this directory is 31 known to be nonexistent, so set DIRDATA to an empty vector. 32 Return -1 (setting errno) if error, 0 otherwise. */ 33 34struct dirdata 35{ 36 size_t nnames; /* Number of names. */ 37 char const **names; /* Sorted names of files in dir, followed by 0. */ 38 char *data; /* Allocated storage for file names. */ 39}; 40 41/* Whether file names in directories should be compared with strcoll. */ 42static bool locale_specific_sorting; 43 44/* Where to go if strcoll fails. */ 45static jmp_buf failed_strcoll; 46 47static bool dir_loop (struct comparison const *, int); 48static int compare_names_for_qsort (void const *, void const *); 49 50 51/* Read a directory and get its vector of names. */ 52 53static bool 54dir_read (struct file_data const *dir, struct dirdata *dirdata) 55{ 56 register struct dirent *next; 57 register size_t i; 58 59 /* Address of block containing the files that are described. */ 60 char const **names; 61 62 /* Number of files in directory. */ 63 size_t nnames; 64 65 /* Allocated and used storage for file name data. */ 66 char *data; 67 size_t data_alloc, data_used; 68 69 dirdata->names = 0; 70 dirdata->data = 0; 71 nnames = 0; 72 data = 0; 73 74 if (dir->desc != -1) 75 { 76 /* Open the directory and check for errors. */ 77 register DIR *reading = opendir (dir->name); 78 if (!reading) 79 return 0; 80 81 /* Initialize the table of filenames. */ 82 83 data_alloc = 512; 84 data_used = 0; 85 dirdata->data = data = xmalloc (data_alloc); 86 87 /* Read the directory entries, and insert the subfiles 88 into the `data' table. */ 89 90 while ((errno = 0, (next = readdir (reading)) != 0)) 91 { 92 char *d_name = next->d_name; 93 size_t d_size = NAMLEN (next) + 1; 94 95 /* Ignore "." and "..". */ 96 if (d_name[0] == '.' 97 && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0))) 98 continue; 99 100 if (excluded_filename (excluded, d_name)) 101 continue; 102 103 while (data_alloc < data_used + d_size) 104 { 105 if (PTRDIFF_MAX / 2 <= data_alloc) 106 xalloc_die (); 107 dirdata->data = data = xrealloc (data, data_alloc *= 2); 108 } 109 110 memcpy (data + data_used, d_name, d_size); 111 data_used += d_size; 112 nnames++; 113 } 114 if (errno) 115 { 116 int e = errno; 117 closedir (reading); 118 errno = e; 119 return 0; 120 } 121#if CLOSEDIR_VOID 122 closedir (reading); 123#else 124 if (closedir (reading) != 0) 125 return 0; 126#endif 127 } 128 129 /* Create the `names' table from the `data' table. */ 130 if (PTRDIFF_MAX / sizeof *names - 1 <= nnames) 131 xalloc_die (); 132 dirdata->names = names = xmalloc ((nnames + 1) * sizeof *names); 133 dirdata->nnames = nnames; 134 for (i = 0; i < nnames; i++) 135 { 136 names[i] = data; 137 data += strlen (data) + 1; 138 } 139 names[nnames] = 0; 140 return 1; 141} 142 143/* Compare file names, returning a value compatible with strcmp. */ 144 145static int 146compare_names (char const *name1, char const *name2) 147{ 148 if (ignore_file_name_case) 149 { 150 int r = strcasecmp (name1, name2); 151 if (r) 152 return r; 153 } 154 155 if (locale_specific_sorting) 156 { 157 int r; 158 errno = 0; 159 r = strcoll (name1, name2); 160 if (errno) 161 { 162 error (0, errno, _("cannot compare file names `%s' and `%s'"), 163 name1, name2); 164 longjmp (failed_strcoll, 1); 165 } 166 if (r) 167 return r; 168 } 169 170 return file_name_cmp (name1, name2); 171} 172 173/* A wrapper for compare_names suitable as an argument for qsort. */ 174 175static int 176compare_names_for_qsort (void const *file1, void const *file2) 177{ 178 char const *const *f1 = file1; 179 char const *const *f2 = file2; 180 return compare_names (*f1, *f2); 181} 182 183/* Compare the contents of two directories named in CMP. 184 This is a top-level routine; it does everything necessary for diff 185 on two directories. 186 187 CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist, 188 but pretend it is empty. Likewise for CMP->file[1]. 189 190 HANDLE_FILE is a caller-provided subroutine called to handle each file. 191 It gets three operands: CMP, name of file in dir 0, name of file in dir 1. 192 These names are relative to the original working directory. 193 194 For a file that appears in only one of the dirs, one of the name-args 195 to HANDLE_FILE is zero. 196 197 Returns the maximum of all the values returned by HANDLE_FILE, 198 or EXIT_TROUBLE if trouble is encountered in opening files. */ 199 200int 201diff_dirs (struct comparison const *cmp, 202 int (*handle_file) (struct comparison const *, 203 char const *, char const *)) 204{ 205 struct dirdata dirdata[2]; 206 int volatile val = EXIT_SUCCESS; 207 int i; 208 209 if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0)) 210 && (cmp->file[1].desc == -1 || dir_loop (cmp, 1))) 211 { 212 error (0, 0, "%s: recursive directory loop", 213 cmp->file[cmp->file[0].desc == -1].name); 214 return EXIT_TROUBLE; 215 } 216 217 /* Get contents of both dirs. */ 218 for (i = 0; i < 2; i++) 219 if (! dir_read (&cmp->file[i], &dirdata[i])) 220 { 221 perror_with_name (cmp->file[i].name); 222 val = EXIT_TROUBLE; 223 } 224 225 if (val == EXIT_SUCCESS) 226 { 227 char const **volatile names[2]; 228 names[0] = dirdata[0].names; 229 names[1] = dirdata[1].names; 230 231 /* Use locale-specific sorting if possible, else native byte order. */ 232 locale_specific_sorting = 1; 233 if (setjmp (failed_strcoll)) 234 locale_specific_sorting = 0; 235 236 /* Sort the directories. */ 237 for (i = 0; i < 2; i++) 238 qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names, 239 compare_names_for_qsort); 240 241 /* If `-S name' was given, and this is the topmost level of comparison, 242 ignore all file names less than the specified starting name. */ 243 244 if (starting_file && ! cmp->parent) 245 { 246 while (*names[0] && compare_names (*names[0], starting_file) < 0) 247 names[0]++; 248 while (*names[1] && compare_names (*names[1], starting_file) < 0) 249 names[1]++; 250 } 251 252 /* Loop while files remain in one or both dirs. */ 253 while (*names[0] || *names[1]) 254 { 255 /* Compare next name in dir 0 with next name in dir 1. 256 At the end of a dir, 257 pretend the "next name" in that dir is very large. */ 258 int nameorder = (!*names[0] ? 1 : !*names[1] ? -1 259 : compare_names (*names[0], *names[1])); 260 int v1 = (*handle_file) (cmp, 261 0 < nameorder ? 0 : *names[0]++, 262 nameorder < 0 ? 0 : *names[1]++); 263 if (val < v1) 264 val = v1; 265 } 266 } 267 268 for (i = 0; i < 2; i++) 269 { 270 if (dirdata[i].names) 271 free (dirdata[i].names); 272 if (dirdata[i].data) 273 free (dirdata[i].data); 274 } 275 276 return val; 277} 278 279/* Return nonzero if CMP is looping recursively in argument I. */ 280 281static bool 282dir_loop (struct comparison const *cmp, int i) 283{ 284 struct comparison const *p = cmp; 285 while ((p = p->parent)) 286 if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat)) 287 return 1; 288 return 0; 289} 290