ld/libdep_plugin.c

   1 /* libdeps plugin for the GNU linker.
   2    Copyright (C) 2020-2025 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #include "sysdep.h"
  22 #include "bfd.h"
  23 #if BFD_SUPPORTS_PLUGINS
  24 #include "plugin-api.h"
  25
  26 #include <ctype.h> /* For isspace.  */
  27
  28 extern enum ld_plugin_status onload (struct ld_plugin_tv *tv);
  29
  30 /* Helper for calling plugin api message function.  */
  31 #define TV_MESSAGE if (tv_message) (*tv_message)
  32
  33 /* Function pointers to cache hooks passed at onload time.  */
  34 static ld_plugin_register_claim_file tv_register_claim_file = 0;
  35 static ld_plugin_register_all_symbols_read tv_register_all_symbols_read = 0;
  36 static ld_plugin_register_cleanup tv_register_cleanup = 0;
  37 static ld_plugin_message tv_message = 0;
  38 static ld_plugin_add_input_library tv_add_input_library = 0;
  39 static ld_plugin_set_extra_library_path tv_set_extra_library_path = 0;
  40
  41 /* Handle/record information received in a transfer vector entry.  */
  42 static enum ld_plugin_status
  43 parse_tv_tag (struct ld_plugin_tv *tv)
  44 {
  45 #define SETVAR(x) x = tv->tv_u.x
  46   switch (tv->tv_tag)
  47     {
  48       case LDPT_REGISTER_CLAIM_FILE_HOOK:
  49         SETVAR(tv_register_claim_file);
  50         break;
  51       case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
  52         SETVAR(tv_register_all_symbols_read);
  53         break;
  54       case LDPT_REGISTER_CLEANUP_HOOK:
  55         SETVAR(tv_register_cleanup);
  56         break;
  57       case LDPT_MESSAGE:
  58         SETVAR(tv_message);
  59         break;
  60       case LDPT_ADD_INPUT_LIBRARY:
  61         SETVAR(tv_add_input_library);
  62         break;
  63       case LDPT_SET_EXTRA_LIBRARY_PATH:
  64         SETVAR(tv_set_extra_library_path);
  65         break;
  66       default:
  67         break;
  68     }
  69 #undef SETVAR
  70   return LDPS_OK;
  71 }
  72
  73 /* Defs for archive parsing.  */
  74 #define ARMAGSIZE       8
  75 typedef struct arhdr
  76 {
  77   char ar_name[16];
  78   char ar_date[12];
  79   char ar_uid[6];
  80   char ar_gid[6];
  81   char ar_mode[8];
  82   char ar_size[10];
  83   char ar_fmag[2];
  84 } arhdr;
  85
  86 typedef struct linerec
  87 {
  88   struct linerec *next;
  89   char line[];
  90 } linerec;
  91
  92 #define LIBDEPS "__.LIBDEP/ "
  93
  94 static linerec *line_head, **line_tail = &line_head;
  95
  96 static enum ld_plugin_status
  97 get_libdeps (int fd)
  98 {
  99   arhdr ah;
 100   int len;
 101   unsigned long mlen;
 102   size_t amt;
 103   linerec *lr;
 104   enum ld_plugin_status rc = LDPS_NO_SYMS;
 105
 106   lseek (fd, ARMAGSIZE, SEEK_SET);
 107   for (;;)
 108     {
 109       len = read (fd, (void *) &ah, sizeof (ah));
 110       if (len != sizeof (ah))
 111         break;
 112       mlen = strtoul (ah.ar_size, NULL, 10);
 113       if (!mlen || strncmp (ah.ar_name, LIBDEPS, sizeof (LIBDEPS)-1))
 114         {
 115           lseek (fd, mlen, SEEK_CUR);
 116           continue;
 117         }
 118       amt = mlen + sizeof (linerec);
 119       if (amt <= mlen)
 120         return LDPS_ERR;
 121       lr = malloc (amt);
 122       if (!lr)
 123         return LDPS_ERR;
 124       lr->next = NULL;
 125       len = read (fd, lr->line, mlen);
 126       lr->line[mlen-1] = '\0';
 127       *line_tail = lr;
 128       line_tail = &lr->next;
 129       rc = LDPS_OK;
 130       break;
 131     }
 132   return rc;
 133 }
 134
 135 /* Parse arguments in-place as contiguous C-strings
 136    and return the number of arguments.  */
 137
 138 static int
 139 parse_libdep (char *str)
 140 {
 141   char *src, *dst;
 142   char quote;
 143   int narg;
 144
 145   src = dst = str;
 146
 147   for (; isspace ((unsigned char) *src); ++src)
 148     ;
 149
 150   if (*src == '\0')
 151     return 0;
 152
 153   narg = 1;
 154   quote = 0;
 155
 156   while (*src)
 157     {
 158       if (*src == '\'' || *src == '\"')
 159         {
 160           if (!quote)
 161             quote = *src++;
 162           else if (*src == quote)
 163             {
 164               ++src;
 165               quote = 0;
 166             }
 167           else
 168             *dst++ = *src++;
 169         }
 170       else if (!quote && isspace ((unsigned char) *src))
 171         {
 172           ++narg;
 173           ++src;
 174           *dst++ = '\0';
 175           for (; isspace ((unsigned char) *src); ++src);
 176         }
 177       else
 178         *dst++ = *src++;
 179     }
 180
 181   *dst = '\0';
 182
 183   if (quote)
 184     {
 185       TV_MESSAGE (LDPL_WARNING,
 186                   "libdep syntax error: unterminated quoted string");
 187       return 0;
 188     }
 189
 190   return narg;
 191 }
 192
 193 static char *prevfile;
 194
 195 /* Standard plugin API registerable hook.  */
 196
 197 static enum ld_plugin_status
 198 onclaim_file (const struct ld_plugin_input_file *file, int *claimed)
 199 {
 200   enum ld_plugin_status rv;
 201
 202   *claimed = 0;
 203
 204   /* If we've already seen this file, ignore it.  */
 205   if (prevfile && !strcmp (file->name, prevfile))
 206     return LDPS_OK;
 207
 208   /* If it's not an archive member, ignore it.  */
 209   if (!file->offset)
 210     return LDPS_OK;
 211
 212   if (prevfile)
 213     free (prevfile);
 214
 215   prevfile = strdup (file->name);
 216   if (!prevfile)
 217     return LDPS_ERR;
 218
 219   /* This hook only gets called on actual object files.
 220      We have to examine the archive ourselves, to find
 221      our LIBDEPS member.  */
 222   rv = get_libdeps (file->fd);
 223   if (rv == LDPS_ERR)
 224     return rv;
 225
 226   if (rv == LDPS_OK)
 227     {
 228       linerec *lr = (linerec *)line_tail;
 229       /* Inform the user/testsuite.  */
 230       TV_MESSAGE (LDPL_INFO, "got deps for library %s: %s",
 231                   file->name, lr->line);
 232       fflush (NULL);
 233     }
 234
 235   return LDPS_OK;
 236 }
 237
 238 /* Standard plugin API registerable hook.  */
 239
 240 static enum ld_plugin_status
 241 onall_symbols_read (void)
 242 {
 243   linerec *lr;
 244   int nargs;
 245   char const *arg;
 246   enum ld_plugin_status rv = LDPS_OK;
 247
 248   while ((lr = line_head))
 249     {
 250       line_head = lr->next;
 251       nargs = parse_libdep (lr->line);
 252       arg = lr->line;
 253
 254       int i;
 255       for (i = 0; i < nargs; i++, arg = strchr (arg, '\0') + 1)
 256         {
 257           if (arg[0] != '-')
 258             {
 259               TV_MESSAGE (LDPL_WARNING, "ignoring libdep argument %s", arg);
 260               fflush (NULL);
 261               continue;
 262             }
 263           if (arg[1] == 'l')
 264             rv = tv_add_input_library (arg + 2);
 265           else if (arg[1] == 'L')
 266             rv = tv_set_extra_library_path (arg + 2);
 267           else
 268             {
 269               TV_MESSAGE (LDPL_WARNING, "ignoring libdep argument %s", arg);
 270               fflush (NULL);
 271             }
 272           if (rv != LDPS_OK)
 273             break;
 274         }
 275       free (lr);
 276     }
 277
 278   line_tail = NULL;
 279   return rv;
 280 }
 281
 282 /* Standard plugin API registerable hook.  */
 283
 284 static enum ld_plugin_status
 285 oncleanup (void)
 286 {
 287   if (prevfile)
 288     {
 289       free (prevfile);
 290       prevfile = NULL;
 291     }
 292
 293   if (line_head)
 294     {
 295       linerec *lr;
 296
 297       while ((lr = line_head))
 298         {
 299           line_head = lr->next;
 300           free (lr);
 301         }
 302
 303       line_tail = NULL;
 304     }
 305
 306   return LDPS_OK;
 307 }
 308
 309 /* Standard plugin API entry point.  */
 310
 311 enum ld_plugin_status
 312 onload (struct ld_plugin_tv *tv)
 313 {
 314   enum ld_plugin_status rv;
 315
 316   /* This plugin requires a valid tv array.  */
 317   if (!tv)
 318     return LDPS_ERR;
 319
 320   /* First entry should always be LDPT_MESSAGE, letting us get
 321      hold of it easily so we can send output straight away.  */
 322   if (tv[0].tv_tag == LDPT_MESSAGE)
 323     tv_message = tv[0].tv_u.tv_message;
 324
 325   do
 326     if ((rv = parse_tv_tag (tv)) != LDPS_OK)
 327       return rv;
 328   while ((tv++)->tv_tag != LDPT_NULL);
 329
 330   /* Register hooks.  */
 331   if (tv_register_claim_file
 332       && tv_register_all_symbols_read
 333       && tv_register_cleanup)
 334     {
 335       (*tv_register_claim_file) (onclaim_file);
 336       (*tv_register_all_symbols_read) (onall_symbols_read);
 337       (*tv_register_cleanup) (oncleanup);
 338     }
 339
 340   fflush (NULL);
 341   return LDPS_OK;
 342 }
 343 #endif /* BFD_SUPPORTS_PLUGINS */