ld/libdep_plugin.c

   1 /* libdeps plugin for the GNU linker.
   2    Copyright (C) 2020-2021 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   linerec *lr;
 103   enum ld_plugin_status rc = LDPS_NO_SYMS;
 104
 105   lseek (fd, ARMAGSIZE, SEEK_SET);
 106   for (;;)
 107     {
 108       len = read (fd, (void *) &ah, sizeof (ah));
 109       if (len != sizeof (ah))
 110         break;
 111       mlen = strtoul (ah.ar_size, NULL, 10);
 112       if (!mlen || strncmp (ah.ar_name, LIBDEPS, sizeof (LIBDEPS)-1))
 113         {
 114           lseek (fd, mlen, SEEK_CUR);
 115           continue;
 116         }
 117       lr = malloc (sizeof (linerec) + mlen);
 118       if (!lr)
 119         return LDPS_ERR;
 120       lr->next = NULL;
 121       len = read (fd, lr->line, mlen);
 122       lr->line[mlen-1] = '\0';
 123       *line_tail = lr;
 124       line_tail = &lr->next;
 125       rc = LDPS_OK;
 126       break;
 127     }
 128   return rc;
 129 }
 130
 131 /* Turn a string into an argvec.  */
 132 static char **
 133 str2vec (char *in)
 134 {
 135   char **res;
 136   char *s, *first, *end;
 137   char *sq, *dq;
 138   int i;
 139
 140   end = in + strlen (in);
 141   s = in;
 142   while (isspace (*s)) s++;
 143   first = s;
 144
 145   i = 1;
 146   while ((s = strchr (s, ' ')))
 147     {
 148       s++;
 149       i++;
 150     }
 151   res = (char **)malloc ((i+1) * sizeof (char *));
 152   if (!res)
 153     return res;
 154
 155   i = 0;
 156   sq = NULL;
 157   dq = NULL;
 158   res[0] = first;
 159   for (s = first; *s; s++)
 160     {
 161       if (*s == '\\')
 162         {
 163           memmove (s, s+1, end-s-1);
 164           end--;
 165         }
 166       if (isspace (*s))
 167         {
 168           if (sq || dq)
 169             continue;
 170           *s++ = '\0';
 171           while (isspace (*s)) s++;
 172           if (*s)
 173             res[++i] = s;
 174         }
 175       if (*s == '\'' && !dq)
 176         {
 177           if (sq)
 178             {
 179               memmove (sq, sq+1, s-sq-1);
 180               memmove (s-2, s+1, end-s-1);
 181               end -= 2;
 182               s--;
 183               sq = NULL;
 184             }
 185           else
 186             {
 187               sq = s;
 188             }
 189         }
 190       if (*s == '"' && !sq)
 191         {
 192           if (dq)
 193             {
 194               memmove (dq, dq+1, s-dq-1);
 195               memmove (s-2, s+1, end-s-1);
 196               end -= 2;
 197               s--;
 198               dq = NULL;
 199             }
 200           else
 201             {
 202               dq = s;
 203             }
 204         }
 205     }
 206   res[++i] = NULL;
 207   return res;
 208 }
 209
 210 static char *prevfile;
 211
 212 /* Standard plugin API registerable hook.  */
 213 static enum ld_plugin_status
 214 onclaim_file (const struct ld_plugin_input_file *file, int *claimed)
 215 {
 216   enum ld_plugin_status rv;
 217
 218   *claimed = 0;
 219
 220   /* If we've already seen this file, ignore it.  */
 221   if (prevfile && !strcmp (file->name, prevfile))
 222     return LDPS_OK;
 223
 224   /* If it's not an archive member, ignore it.  */
 225   if (!file->offset)
 226     return LDPS_OK;
 227
 228   if (prevfile)
 229     free (prevfile);
 230
 231   prevfile = strdup (file->name);
 232   if (!prevfile)
 233     return LDPS_ERR;
 234
 235   /* This hook only gets called on actual object files.
 236    * We have to examine the archive ourselves, to find
 237    * our LIBDEPS member.  */
 238   rv = get_libdeps (file->fd);
 239   if (rv == LDPS_ERR)
 240     return rv;
 241
 242   if (rv == LDPS_OK)
 243     {
 244       linerec *lr = (linerec *)line_tail;
 245       /* Inform the user/testsuite.  */
 246       TV_MESSAGE (LDPL_INFO, "got deps for library %s: %s",
 247                   file->name, lr->line);
 248       fflush (NULL);
 249     }
 250
 251   return LDPS_OK;
 252 }
 253
 254 /* Standard plugin API registerable hook.  */
 255 static enum ld_plugin_status
 256 onall_symbols_read (void)
 257 {
 258   linerec *lr;
 259   char **vec;
 260   enum ld_plugin_status rv = LDPS_OK;
 261
 262   while ((lr = line_head))
 263     {
 264       line_head = lr->next;
 265       vec = str2vec (lr->line);
 266       if (vec)
 267         {
 268           int i;
 269           for (i = 0; vec[i]; i++)
 270             {
 271               if (vec[i][0] != '-')
 272                 {
 273                   TV_MESSAGE (LDPL_WARNING, "ignoring libdep argument %s",
 274                               vec[i]);
 275                   fflush (NULL);
 276                   continue;
 277                 }
 278               if (vec[i][1] == 'l')
 279                 rv = tv_add_input_library (vec[i]+2);
 280               else if (vec[i][1] == 'L')
 281                 rv = tv_set_extra_library_path (vec[i]+2);
 282               else
 283                 {
 284                   TV_MESSAGE (LDPL_WARNING, "ignoring libdep argument %s",
 285                               vec[i]);
 286                   fflush (NULL);
 287                 }
 288               if (rv != LDPS_OK)
 289                 break;
 290             }
 291           free (vec);
 292         }
 293       free (lr);
 294     }
 295   line_tail = NULL;
 296   return rv;
 297 }
 298
 299 /* Standard plugin API registerable hook.  */
 300 static enum ld_plugin_status
 301 oncleanup (void)
 302 {
 303   if (prevfile)
 304     {
 305       free (prevfile);
 306       prevfile = NULL;
 307     }
 308   if (line_head)
 309     {
 310       linerec *lr;
 311       while ((lr = line_head))
 312         {
 313           line_head = lr->next;
 314           free (lr);
 315         }
 316       line_tail = NULL;
 317     }
 318   return LDPS_OK;
 319 }
 320
 321 /* Standard plugin API entry point.  */
 322 enum ld_plugin_status
 323 onload (struct ld_plugin_tv *tv)
 324 {
 325   enum ld_plugin_status rv;
 326
 327   /* This plugin requires a valid tv array.  */
 328   if (!tv)
 329     return LDPS_ERR;
 330
 331   /* First entry should always be LDPT_MESSAGE, letting us get
 332      hold of it easily so we can send output straight away.  */
 333   if (tv[0].tv_tag == LDPT_MESSAGE)
 334     tv_message = tv[0].tv_u.tv_message;
 335
 336   do
 337     if ((rv = parse_tv_tag (tv)) != LDPS_OK)
 338       return rv;
 339   while ((tv++)->tv_tag != LDPT_NULL);
 340
 341   /* Register hooks.  */
 342   if (tv_register_claim_file
 343       && tv_register_all_symbols_read
 344       && tv_register_cleanup)
 345     {
 346       (*tv_register_claim_file) (onclaim_file);
 347       (*tv_register_all_symbols_read) (onall_symbols_read);
 348       (*tv_register_cleanup) (oncleanup);
 349     }
 350   fflush (NULL);
 351   return LDPS_OK;
 352 }
 353 #endif /* BFD_SUPPORTS_PLUGINS */