1/* Path manipulation routines for GDB and gdbserver. 2 3 Copyright (C) 1986-2020 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20#include "common-defs.h" 21#include "pathstuff.h" 22#include "host-defs.h" 23#include "filenames.h" 24#include "gdb_tilde_expand.h" 25 26#ifdef USE_WIN32API 27#include <windows.h> 28#endif 29 30/* See gdbsupport/pathstuff.h. */ 31 32gdb::unique_xmalloc_ptr<char> 33gdb_realpath (const char *filename) 34{ 35/* On most hosts, we rely on canonicalize_file_name to compute 36 the FILENAME's realpath. 37 38 But the situation is slightly more complex on Windows, due to some 39 versions of GCC which were reported to generate paths where 40 backlashes (the directory separator) were doubled. For instance: 41 c:\\some\\double\\slashes\\dir 42 ... instead of ... 43 c:\some\double\slashes\dir 44 Those double-slashes were getting in the way when comparing paths, 45 for instance when trying to insert a breakpoint as follow: 46 (gdb) b c:/some/double/slashes/dir/foo.c:4 47 No source file named c:/some/double/slashes/dir/foo.c:4. 48 (gdb) b c:\some\double\slashes\dir\foo.c:4 49 No source file named c:\some\double\slashes\dir\foo.c:4. 50 To prevent this from happening, we need this function to always 51 strip those extra backslashes. While canonicalize_file_name does 52 perform this simplification, it only works when the path is valid. 53 Since the simplification would be useful even if the path is not 54 valid (one can always set a breakpoint on a file, even if the file 55 does not exist locally), we rely instead on GetFullPathName to 56 perform the canonicalization. */ 57 58#if defined (_WIN32) 59 { 60 char buf[MAX_PATH]; 61 DWORD len = GetFullPathName (filename, MAX_PATH, buf, NULL); 62 63 /* The file system is case-insensitive but case-preserving. 64 So it is important we do not lowercase the path. Otherwise, 65 we might not be able to display the original casing in a given 66 path. */ 67 if (len > 0 && len < MAX_PATH) 68 return make_unique_xstrdup (buf); 69 } 70#else 71 { 72 char *rp = canonicalize_file_name (filename); 73 74 if (rp != NULL) 75 return gdb::unique_xmalloc_ptr<char> (rp); 76 } 77#endif 78 79 /* This system is a lost cause, just dup the buffer. */ 80 return make_unique_xstrdup (filename); 81} 82 83/* See gdbsupport/pathstuff.h. */ 84 85gdb::unique_xmalloc_ptr<char> 86gdb_realpath_keepfile (const char *filename) 87{ 88 const char *base_name = lbasename (filename); 89 char *dir_name; 90 char *result; 91 92 /* Extract the basename of filename, and return immediately 93 a copy of filename if it does not contain any directory prefix. */ 94 if (base_name == filename) 95 return make_unique_xstrdup (filename); 96 97 dir_name = (char *) alloca ((size_t) (base_name - filename + 2)); 98 /* Allocate enough space to store the dir_name + plus one extra 99 character sometimes needed under Windows (see below), and 100 then the closing \000 character. */ 101 strncpy (dir_name, filename, base_name - filename); 102 dir_name[base_name - filename] = '\000'; 103 104#ifdef HAVE_DOS_BASED_FILE_SYSTEM 105 /* We need to be careful when filename is of the form 'd:foo', which 106 is equivalent of d:./foo, which is totally different from d:/foo. */ 107 if (strlen (dir_name) == 2 && isalpha (dir_name[0]) && dir_name[1] == ':') 108 { 109 dir_name[2] = '.'; 110 dir_name[3] = '\000'; 111 } 112#endif 113 114 /* Canonicalize the directory prefix, and build the resulting 115 filename. If the dirname realpath already contains an ending 116 directory separator, avoid doubling it. */ 117 gdb::unique_xmalloc_ptr<char> path_storage = gdb_realpath (dir_name); 118 const char *real_path = path_storage.get (); 119 if (IS_DIR_SEPARATOR (real_path[strlen (real_path) - 1])) 120 result = concat (real_path, base_name, (char *) NULL); 121 else 122 result = concat (real_path, SLASH_STRING, base_name, (char *) NULL); 123 124 return gdb::unique_xmalloc_ptr<char> (result); 125} 126 127/* See gdbsupport/pathstuff.h. */ 128 129gdb::unique_xmalloc_ptr<char> 130gdb_abspath (const char *path) 131{ 132 gdb_assert (path != NULL && path[0] != '\0'); 133 134 if (path[0] == '~') 135 return gdb_tilde_expand_up (path); 136 137 if (IS_ABSOLUTE_PATH (path) || current_directory == NULL) 138 return make_unique_xstrdup (path); 139 140 /* Beware the // my son, the Emacs barfs, the botch that catch... */ 141 return gdb::unique_xmalloc_ptr<char> 142 (concat (current_directory, 143 IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1]) 144 ? "" : SLASH_STRING, 145 path, (char *) NULL)); 146} 147 148/* See gdbsupport/pathstuff.h. */ 149 150const char * 151child_path (const char *parent, const char *child) 152{ 153 /* The child path must start with the parent path. */ 154 size_t parent_len = strlen (parent); 155 if (filename_ncmp (parent, child, parent_len) != 0) 156 return NULL; 157 158 /* The parent path must be a directory and the child must contain at 159 least one component underneath the parent. */ 160 const char *child_component; 161 if (parent_len > 0 && IS_DIR_SEPARATOR (parent[parent_len - 1])) 162 { 163 /* The parent path ends in a directory separator, so it is a 164 directory. The first child component starts after the common 165 prefix. */ 166 child_component = child + parent_len; 167 } 168 else 169 { 170 /* The parent path does not end in a directory separator. The 171 first character in the child after the common prefix must be 172 a directory separator. 173 174 Note that CHILD must hold at least parent_len characters for 175 filename_ncmp to return zero. If the character at parent_len 176 is nul due to CHILD containing the same path as PARENT, the 177 IS_DIR_SEPARATOR check will fail here. */ 178 if (!IS_DIR_SEPARATOR (child[parent_len])) 179 return NULL; 180 181 /* The first child component starts after the separator after the 182 common prefix. */ 183 child_component = child + parent_len + 1; 184 } 185 186 /* The child must contain at least one non-separator character after 187 the parent. */ 188 while (*child_component != '\0') 189 { 190 if (!IS_DIR_SEPARATOR (*child_component)) 191 return child_component; 192 193 child_component++; 194 } 195 return NULL; 196} 197 198/* See gdbsupport/pathstuff.h. */ 199 200bool 201contains_dir_separator (const char *path) 202{ 203 for (; *path != '\0'; path++) 204 { 205 if (IS_DIR_SEPARATOR (*path)) 206 return true; 207 } 208 209 return false; 210} 211 212/* See gdbsupport/pathstuff.h. */ 213 214std::string 215get_standard_cache_dir () 216{ 217#ifdef __APPLE__ 218#define HOME_CACHE_DIR "Library/Caches" 219#else 220#define HOME_CACHE_DIR ".cache" 221#endif 222 223#ifndef __APPLE__ 224 const char *xdg_cache_home = getenv ("XDG_CACHE_HOME"); 225 if (xdg_cache_home != NULL) 226 { 227 /* Make sure the path is absolute and tilde-expanded. */ 228 gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (xdg_cache_home)); 229 return string_printf ("%s/gdb", abs.get ()); 230 } 231#endif 232 233 const char *home = getenv ("HOME"); 234 if (home != NULL) 235 { 236 /* Make sure the path is absolute and tilde-expanded. */ 237 gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (home)); 238 return string_printf ("%s/" HOME_CACHE_DIR "/gdb", abs.get ()); 239 } 240 241 return {}; 242} 243 244/* See gdbsupport/pathstuff.h. */ 245 246std::string 247get_standard_temp_dir () 248{ 249#ifdef WIN32 250 const char *tmp = getenv ("TMP"); 251 if (tmp != nullptr) 252 return tmp; 253 254 tmp = getenv ("TEMP"); 255 if (tmp != nullptr) 256 return tmp; 257 258 error (_("Couldn't find temp dir path, both TMP and TEMP are unset.")); 259 260#else 261 const char *tmp = getenv ("TMPDIR"); 262 if (tmp != nullptr) 263 return tmp; 264 265 return "/tmp"; 266#endif 267} 268 269/* See gdbsupport/pathstuff.h. */ 270 271const char * 272get_shell () 273{ 274 const char *ret = getenv ("SHELL"); 275 if (ret == NULL) 276 ret = "/bin/sh"; 277 278 return ret; 279} 280 281/* See gdbsupport/pathstuff.h. */ 282 283gdb::char_vector 284make_temp_filename (const std::string &f) 285{ 286 gdb::char_vector filename_temp (f.length () + 8); 287 strcpy (filename_temp.data (), f.c_str ()); 288 strcat (filename_temp.data () + f.size (), "-XXXXXX"); 289 return filename_temp; 290} 291