gcc/plugin.cc

   1 /* Support for GCC plugin mechanism.
   2    Copyright (C) 2009-2023 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC 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, or (at your option)
   9 any later version.
  10
  11 GCC 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 GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* This file contains the support for GCC plugin mechanism based on the
  21    APIs described in doc/plugin.texi.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "options.h"
  27 #include "tree-pass.h"
  28 #include "diagnostic-core.h"
  29 #include "flags.h"
  30 #include "intl.h"
  31 #include "plugin.h"
  32
  33 #ifdef ENABLE_PLUGIN
  34 #include "plugin-version.h"
  35 #endif
  36
  37 #ifdef __MINGW32__
  38 #ifndef WIN32_LEAN_AND_MEAN
  39 #define WIN32_LEAN_AND_MEAN
  40 #endif
  41 #ifndef NOMINMAX
  42 #define NOMINMAX
  43 #endif
  44 #define WIN32_LEAN_AND_MEAN
  45 #include <windows.h>
  46 #endif
  47
  48 #define GCC_PLUGIN_STRINGIFY0(X) #X
  49 #define GCC_PLUGIN_STRINGIFY1(X) GCC_PLUGIN_STRINGIFY0 (X)
  50
  51 /* Event names as strings.  Keep in sync with enum plugin_event.  */
  52 static const char *plugin_event_name_init[] =
  53 {
  54 # define DEFEVENT(NAME) GCC_PLUGIN_STRINGIFY1 (NAME),
  55 # include "plugin.def"
  56 # undef DEFEVENT
  57 };
  58
  59 /* A printf format large enough for the largest event above.  */
  60 #define FMT_FOR_PLUGIN_EVENT "%-32s"
  61
  62 const char **plugin_event_name = plugin_event_name_init;
  63
  64 /* Event hashtable helpers.  */
  65
  66 struct event_hasher : nofree_ptr_hash <const char *>
  67 {
  68   static inline hashval_t hash (const char **);
  69   static inline bool equal (const char **, const char **);
  70 };
  71
  72 /* Helper function for the event hash table that hashes the entry V.  */
  73
  74 inline hashval_t
  75 event_hasher::hash (const char **v)
  76 {
  77   return htab_hash_string (*v);
  78 }
  79
  80 /* Helper function for the event hash table that compares the name of an
  81    existing entry (S1) with the given string (S2).  */
  82
  83 inline bool
  84 event_hasher::equal (const char **s1, const char **s2)
  85 {
  86   return !strcmp (*s1, *s2);
  87 }
  88
  89 /* A hash table to map event names to the position of the names in the
  90    plugin_event_name table.  */
  91 static hash_table<event_hasher> *event_tab;
  92
  93 /* Keep track of the limit of allocated events and space ready for
  94    allocating events.  */
  95 static int event_last = PLUGIN_EVENT_FIRST_DYNAMIC;
  96 static int event_horizon = PLUGIN_EVENT_FIRST_DYNAMIC;
  97
  98 /* Hash table for the plugin_name_args objects created during command-line
  99    parsing.  */
 100 static htab_t plugin_name_args_tab = NULL;
 101
 102 /* List node for keeping track of plugin-registered callback.  */
 103 struct callback_info
 104 {
 105   const char *plugin_name;   /* Name of plugin that registers the callback.  */
 106   plugin_callback_func func; /* Callback to be called.  */
 107   void *user_data;           /* plugin-specified data.  */
 108   struct callback_info *next;
 109 };
 110
 111 /* An array of lists of 'callback_info' objects indexed by the event id.  */
 112 static struct callback_info *plugin_callbacks_init[PLUGIN_EVENT_FIRST_DYNAMIC];
 113 static struct callback_info **plugin_callbacks = plugin_callbacks_init;
 114
 115 /* For invoke_plugin_callbacks(), see plugin.h.  */
 116 bool flag_plugin_added = false;
 117
 118 #ifdef ENABLE_PLUGIN
 119 /* Each plugin should define an initialization function with exactly
 120    this name.  */
 121 static const char *str_plugin_init_func_name = "plugin_init";
 122
 123 /* Each plugin should define this symbol to assert that it is
 124    distributed under a GPL-compatible license.  */
 125 static const char *str_license = "plugin_is_GPL_compatible";
 126 #endif
 127
 128 /* Helper function for hashing the base_name of the plugin_name_args
 129    structure to be inserted into the hash table.  */
 130
 131 static hashval_t
 132 htab_hash_plugin (const void *p)
 133 {
 134   const struct plugin_name_args *plugin = (const struct plugin_name_args *) p;
 135   return htab_hash_string (plugin->base_name);
 136  }
 137
 138 /* Helper function for the hash table that compares the base_name of the
 139    existing entry (S1) with the given string (S2).  */
 140
 141 static int
 142 htab_str_eq (const void *s1, const void *s2)
 143 {
 144   const struct plugin_name_args *plugin = (const struct plugin_name_args *) s1;
 145   return !strcmp (plugin->base_name, (const char *) s2);
 146 }
 147
 148
 149 /* Given a plugin's full-path name FULL_NAME, e.g. /pass/to/NAME.so,
 150    return NAME.  */
 151
 152 static char *
 153 get_plugin_base_name (const char *full_name)
 154 {
 155   /* First get the base name part of the full-path name, i.e. NAME.so.  */
 156   char *base_name = xstrdup (lbasename (full_name));
 157
 158   /* Then get rid of the extension in the name, e.g., .so.  */
 159   strip_off_ending (base_name, strlen (base_name));
 160
 161   return base_name;
 162 }
 163
 164
 165 /* Create a plugin_name_args object for the given plugin and insert it
 166    to the hash table. This function is called when
 167    -fplugin=/path/to/NAME.so or -fplugin=NAME option is processed.  */
 168
 169 void
 170 add_new_plugin (const char* plugin_name)
 171 {
 172   struct plugin_name_args *plugin;
 173   void **slot;
 174   char *base_name;
 175   bool name_is_short;
 176   const char *pc;
 177
 178   flag_plugin_added = true;
 179
 180   /* Replace short names by their full path when relevant.  */
 181   name_is_short  = !IS_ABSOLUTE_PATH (plugin_name);
 182   for (pc = plugin_name; name_is_short && *pc; pc++)
 183     if (*pc == '.' || IS_DIR_SEPARATOR (*pc))
 184       name_is_short = false;
 185
 186   if (name_is_short)
 187     {
 188       base_name = CONST_CAST (char*, plugin_name);
 189
 190 #if defined(__MINGW32__)
 191       static const char plugin_ext[] = ".dll";
 192 #elif defined(__APPLE__)
 193       /* macOS has two types of libraries: dynamic libraries (.dylib) and
 194          plugins (.bundle). Both can be used with dlopen()/dlsym() but the
 195          former cannot be linked at build time (i.e., with the -lfoo linker
 196          option). A GCC plugin is therefore probably a macOS plugin but their
 197          use seems to be quite rare and the .bundle extension is more of a
 198          recommendation rather than the rule. This raises the questions of how
 199          well they are supported by tools (e.g., libtool). So to avoid
 200          complications let's use the .dylib extension for now. In the future,
 201          if this proves to be an issue, we can always check for both
 202          extensions.  */
 203       static const char plugin_ext[] = ".dylib";
 204 #else
 205       static const char plugin_ext[] = ".so";
 206 #endif
 207
 208       plugin_name = concat (default_plugin_dir_name (), "/",
 209                             plugin_name, plugin_ext, NULL);
 210       if (access (plugin_name, R_OK))
 211         fatal_error
 212           (input_location,
 213            "inaccessible plugin file %s expanded from short plugin name %s: %m",
 214            plugin_name, base_name);
 215     }
 216   else
 217     base_name = get_plugin_base_name (plugin_name);
 218
 219   /* If this is the first -fplugin= option we encounter, create
 220      'plugin_name_args_tab' hash table.  */
 221   if (!plugin_name_args_tab)
 222     plugin_name_args_tab = htab_create (10, htab_hash_plugin, htab_str_eq,
 223                                         NULL);
 224
 225   slot = htab_find_slot_with_hash (plugin_name_args_tab, base_name,
 226                                    htab_hash_string (base_name), INSERT);
 227
 228   /* If the same plugin (name) has been specified earlier, either emit an
 229      error or a warning message depending on if they have identical full
 230      (path) names.  */
 231   if (*slot)
 232     {
 233       plugin = (struct plugin_name_args *) *slot;
 234       if (strcmp (plugin->full_name, plugin_name))
 235         error ("plugin %qs was specified with different paths: %qs and %qs",
 236                plugin->base_name, plugin->full_name, plugin_name);
 237       return;
 238     }
 239
 240   plugin = XCNEW (struct plugin_name_args);
 241   plugin->base_name = base_name;
 242   plugin->full_name = plugin_name;
 243
 244   *slot = plugin;
 245 }
 246
 247
 248 /* Parse the -fplugin-arg-<name>-<key>[=<value>] option and create a
 249    'plugin_argument' object for the parsed key-value pair. ARG is
 250    the <name>-<key>[=<value>] part of the option.  */
 251
 252 void
 253 parse_plugin_arg_opt (const char *arg)
 254 {
 255   size_t len = 0, name_len = 0, key_len = 0, value_len = 0;
 256   const char *ptr, *name_start = arg, *key_start = NULL, *value_start = NULL;
 257   char *name, *key, *value;
 258   void **slot;
 259   bool name_parsed = false, key_parsed = false;
 260
 261   /* Iterate over the ARG string and identify the starting character position
 262      of 'name', 'key', and 'value' and their lengths.  */
 263   for (ptr = arg; *ptr; ++ptr)
 264     {
 265       /* Only the first '-' encountered is considered a separator between
 266          'name' and 'key'. All the subsequent '-'s are considered part of
 267          'key'. For example, given -fplugin-arg-foo-bar-primary-key=value,
 268          the plugin name is 'foo' and the key is 'bar-primary-key'.  */
 269       if (*ptr == '-' && !name_parsed)
 270         {
 271           name_len = len;
 272           len = 0;
 273           key_start = ptr + 1;
 274           name_parsed = true;
 275           continue;
 276         }
 277       else if (*ptr == '=')
 278         {
 279           if (!key_parsed)
 280             {
 281               key_len = len;
 282               len = 0;
 283               value_start = ptr + 1;
 284               key_parsed = true;
 285             }
 286           continue;
 287         }
 288       else
 289         ++len;
 290     }
 291
 292   if (!key_start)
 293     {
 294       error ("malformed option %<-fplugin-arg-%s%>: "
 295              "missing %<-<key>[=<value>]%>",
 296              arg);
 297       return;
 298     }
 299
 300   /* If the option doesn't contain the 'value' part, LEN is the KEY_LEN.
 301      Otherwise, it is the VALUE_LEN.  */
 302   if (!value_start)
 303     key_len = len;
 304   else
 305     value_len = len;
 306
 307   name = XNEWVEC (char, name_len + 1);
 308   strncpy (name, name_start, name_len);
 309   name[name_len] = '\0';
 310
 311   /* Check if the named plugin has already been specified earlier in the
 312      command-line.  */
 313   if (plugin_name_args_tab
 314       && ((slot = htab_find_slot_with_hash (plugin_name_args_tab, name,
 315                                             htab_hash_string (name), NO_INSERT))
 316           != NULL))
 317     {
 318       struct plugin_name_args *plugin = (struct plugin_name_args *) *slot;
 319
 320       key = XNEWVEC (char, key_len + 1);
 321       strncpy (key, key_start, key_len);
 322       key[key_len] = '\0';
 323       if (value_start)
 324         {
 325           value = XNEWVEC (char, value_len + 1);
 326           strncpy (value, value_start, value_len);
 327           value[value_len] = '\0';
 328         }
 329       else
 330         value = NULL;
 331
 332       /* Create a plugin_argument object for the parsed key-value pair.
 333          If there are already arguments for this plugin, we will need to
 334          adjust the argument array size by creating a new array and deleting
 335          the old one. If the performance ever becomes an issue, we can
 336          change the code by pre-allocating a larger array first.  */
 337       if (plugin->argc > 0)
 338         {
 339           struct plugin_argument *args = XNEWVEC (struct plugin_argument,
 340                                                   plugin->argc + 1);
 341           memcpy (args, plugin->argv,
 342                   sizeof (struct plugin_argument) * plugin->argc);
 343           XDELETEVEC (plugin->argv);
 344           plugin->argv = args;
 345           ++plugin->argc;
 346         }
 347       else
 348         {
 349           gcc_assert (plugin->argv == NULL);
 350           plugin->argv = XNEWVEC (struct plugin_argument, 1);
 351           plugin->argc = 1;
 352         }
 353
 354       plugin->argv[plugin->argc - 1].key = key;
 355       plugin->argv[plugin->argc - 1].value = value;
 356     }
 357   else
 358     error ("plugin %s should be specified before %<-fplugin-arg-%s%> "
 359            "in the command line", name, arg);
 360
 361   /* We don't need the plugin's name anymore. Just release it.  */
 362   XDELETEVEC (name);
 363 }
 364
 365 /* Register additional plugin information. NAME is the name passed to
 366    plugin_init. INFO is the information that should be registered. */
 367
 368 static void
 369 register_plugin_info (const char* name, struct plugin_info *info)
 370 {
 371   void **slot = htab_find_slot_with_hash (plugin_name_args_tab, name,
 372                                           htab_hash_string (name), NO_INSERT);
 373   struct plugin_name_args *plugin;
 374
 375   if (slot == NULL)
 376     {
 377       error ("unable to register info for plugin %qs - plugin name not found",
 378              name);
 379       return;
 380     }
 381   plugin = (struct plugin_name_args *) *slot;
 382   plugin->version = info->version;
 383   plugin->help = info->help;
 384 }
 385
 386 /* Look up the event id for NAME.  If the name is not found, return -1
 387    if INSERT is NO_INSERT.  */
 388
 389 int
 390 get_named_event_id (const char *name, enum insert_option insert)
 391 {
 392   const char ***slot;
 393
 394   if (!event_tab)
 395     {
 396       int i;
 397
 398       event_tab = new hash_table<event_hasher> (150);
 399       for (i = 0; i < event_last; i++)
 400         {
 401           slot = event_tab->find_slot (&plugin_event_name[i], INSERT);
 402           gcc_assert (*slot == HTAB_EMPTY_ENTRY);
 403           *slot = &plugin_event_name[i];
 404         }
 405     }
 406   slot = event_tab->find_slot (&name, insert);
 407   if (slot == NULL)
 408     return -1;
 409   if (*slot != HTAB_EMPTY_ENTRY)
 410     return *slot - &plugin_event_name[0];
 411
 412   if (event_last >= event_horizon)
 413     {
 414       event_horizon = event_last * 2;
 415       if (plugin_event_name == plugin_event_name_init)
 416         {
 417           plugin_event_name = XNEWVEC (const char *, event_horizon);
 418           memcpy (plugin_event_name, plugin_event_name_init,
 419                   sizeof plugin_event_name_init);
 420           plugin_callbacks = XNEWVEC (struct callback_info *, event_horizon);
 421           memcpy (plugin_callbacks, plugin_callbacks_init,
 422                   sizeof plugin_callbacks_init);
 423         }
 424       else
 425         {
 426           plugin_event_name
 427             = XRESIZEVEC (const char *, plugin_event_name, event_horizon);
 428           plugin_callbacks = XRESIZEVEC (struct callback_info *,
 429                                          plugin_callbacks, event_horizon);
 430         }
 431       /* All the pointers in the hash table will need to be updated.  */
 432       delete event_tab;
 433       event_tab = NULL;
 434     }
 435   else
 436     *slot = &plugin_event_name[event_last];
 437   plugin_event_name[event_last] = name;
 438   return event_last++;
 439 }
 440
 441 /* Called from the plugin's initialization code. Register a single callback.
 442    This function can be called multiple times.
 443
 444    PLUGIN_NAME - display name for this plugin
 445    EVENT       - which event the callback is for
 446    CALLBACK    - the callback to be called at the event
 447    USER_DATA   - plugin-provided data   */
 448
 449 void
 450 register_callback (const char *plugin_name,
 451                    int event,
 452                    plugin_callback_func callback,
 453                    void *user_data)
 454 {
 455   switch (event)
 456     {
 457       case PLUGIN_PASS_MANAGER_SETUP:
 458         gcc_assert (!callback);
 459         register_pass ((struct register_pass_info *) user_data);
 460         break;
 461       case PLUGIN_INFO:
 462         gcc_assert (!callback);
 463         register_plugin_info (plugin_name, (struct plugin_info *) user_data);
 464         break;
 465       case PLUGIN_REGISTER_GGC_ROOTS:
 466         gcc_assert (!callback);
 467         ggc_register_root_tab ((const struct ggc_root_tab*) user_data);
 468         break;
 469       case PLUGIN_EVENT_FIRST_DYNAMIC:
 470       default:
 471         if (event < PLUGIN_EVENT_FIRST_DYNAMIC || event >= event_last)
 472           {
 473             error ("unknown callback event registered by plugin %s",
 474                    plugin_name);
 475             return;
 476           }
 477       /* Fall through.  */
 478       case PLUGIN_START_PARSE_FUNCTION:
 479       case PLUGIN_FINISH_PARSE_FUNCTION:
 480       case PLUGIN_FINISH_TYPE:
 481       case PLUGIN_FINISH_DECL:
 482       case PLUGIN_START_UNIT:
 483       case PLUGIN_FINISH_UNIT:
 484       case PLUGIN_PRE_GENERICIZE:
 485       case PLUGIN_GGC_START:
 486       case PLUGIN_GGC_MARKING:
 487       case PLUGIN_GGC_END:
 488       case PLUGIN_ATTRIBUTES:
 489       case PLUGIN_PRAGMAS:
 490       case PLUGIN_FINISH:
 491       case PLUGIN_ALL_PASSES_START:
 492       case PLUGIN_ALL_PASSES_END:
 493       case PLUGIN_ALL_IPA_PASSES_START:
 494       case PLUGIN_ALL_IPA_PASSES_END:
 495       case PLUGIN_OVERRIDE_GATE:
 496       case PLUGIN_PASS_EXECUTION:
 497       case PLUGIN_EARLY_GIMPLE_PASSES_START:
 498       case PLUGIN_EARLY_GIMPLE_PASSES_END:
 499       case PLUGIN_NEW_PASS:
 500       case PLUGIN_INCLUDE_FILE:
 501       case PLUGIN_ANALYZER_INIT:
 502         {
 503           struct callback_info *new_callback;
 504           if (!callback)
 505             {
 506               error ("plugin %s registered a null callback function "
 507                      "for event %s", plugin_name, plugin_event_name[event]);
 508               return;
 509             }
 510           new_callback = XNEW (struct callback_info);
 511           new_callback->plugin_name = plugin_name;
 512           new_callback->func = callback;
 513           new_callback->user_data = user_data;
 514           new_callback->next = plugin_callbacks[event];
 515           plugin_callbacks[event] = new_callback;
 516         }
 517         break;
 518     }
 519 }
 520
 521 /* Remove a callback for EVENT which has been registered with for a plugin
 522    PLUGIN_NAME.  Return PLUGEVT_SUCCESS if a matching callback was
 523    found & removed, PLUGEVT_NO_CALLBACK if the event does not have a matching
 524    callback, and PLUGEVT_NO_SUCH_EVENT if EVENT is invalid.  */
 525 int
 526 unregister_callback (const char *plugin_name, int event)
 527 {
 528   struct callback_info *callback, **cbp;
 529
 530   if (event >= event_last)
 531     return PLUGEVT_NO_SUCH_EVENT;
 532
 533   for (cbp = &plugin_callbacks[event]; (callback = *cbp); cbp = &callback->next)
 534     if (strcmp (callback->plugin_name, plugin_name) == 0)
 535       {
 536         *cbp = callback->next;
 537         return PLUGEVT_SUCCESS;
 538       }
 539   return PLUGEVT_NO_CALLBACK;
 540 }
 541
 542 /* Invoke all plugin callbacks registered with the specified event,
 543    called from invoke_plugin_callbacks().  */
 544
 545 int
 546 invoke_plugin_callbacks_full (int event, void *gcc_data)
 547 {
 548   int retval = PLUGEVT_SUCCESS;
 549
 550   timevar_push (TV_PLUGIN_RUN);
 551
 552   switch (event)
 553     {
 554       case PLUGIN_EVENT_FIRST_DYNAMIC:
 555       default:
 556         gcc_assert (event >= PLUGIN_EVENT_FIRST_DYNAMIC);
 557         gcc_assert (event < event_last);
 558       /* Fall through.  */
 559       case PLUGIN_START_PARSE_FUNCTION:
 560       case PLUGIN_FINISH_PARSE_FUNCTION:
 561       case PLUGIN_FINISH_TYPE:
 562       case PLUGIN_FINISH_DECL:
 563       case PLUGIN_START_UNIT:
 564       case PLUGIN_FINISH_UNIT:
 565       case PLUGIN_PRE_GENERICIZE:
 566       case PLUGIN_ATTRIBUTES:
 567       case PLUGIN_PRAGMAS:
 568       case PLUGIN_FINISH:
 569       case PLUGIN_GGC_START:
 570       case PLUGIN_GGC_MARKING:
 571       case PLUGIN_GGC_END:
 572       case PLUGIN_ALL_PASSES_START:
 573       case PLUGIN_ALL_PASSES_END:
 574       case PLUGIN_ALL_IPA_PASSES_START:
 575       case PLUGIN_ALL_IPA_PASSES_END:
 576       case PLUGIN_OVERRIDE_GATE:
 577       case PLUGIN_PASS_EXECUTION:
 578       case PLUGIN_EARLY_GIMPLE_PASSES_START:
 579       case PLUGIN_EARLY_GIMPLE_PASSES_END:
 580       case PLUGIN_NEW_PASS:
 581       case PLUGIN_INCLUDE_FILE:
 582       case PLUGIN_ANALYZER_INIT:
 583         {
 584           /* Iterate over every callback registered with this event and
 585              call it.  */
 586           struct callback_info *callback = plugin_callbacks[event];
 587
 588           if (!callback)
 589             retval = PLUGEVT_NO_CALLBACK;
 590           for ( ; callback; callback = callback->next)
 591             (*callback->func) (gcc_data, callback->user_data);
 592         }
 593         break;
 594
 595       case PLUGIN_PASS_MANAGER_SETUP:
 596       case PLUGIN_REGISTER_GGC_ROOTS:
 597         gcc_assert (false);
 598     }
 599
 600   timevar_pop (TV_PLUGIN_RUN);
 601   return retval;
 602 }
 603
 604 #ifdef ENABLE_PLUGIN
 605
 606 /* Try to initialize PLUGIN. Return true if successful. */
 607
 608 #ifdef __MINGW32__
 609
 610 // Return a message string for last error or NULL if unknown. Must be freed
 611 // with LocalFree().
 612 static inline char *
 613 win32_error_msg ()
 614 {
 615   char *msg;
 616   return FormatMessageA (FORMAT_MESSAGE_ALLOCATE_BUFFER |
 617                          FORMAT_MESSAGE_FROM_SYSTEM |
 618                          FORMAT_MESSAGE_IGNORE_INSERTS |
 619                          FORMAT_MESSAGE_MAX_WIDTH_MASK,
 620                          0,
 621                          GetLastError (),
 622                          MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
 623                          (char*)&msg,
 624                          0,
 625                          0)
 626     ? msg
 627     : NULL;
 628 }
 629
 630 static bool
 631 try_init_one_plugin (struct plugin_name_args *plugin)
 632 {
 633   HMODULE dl_handle;
 634   plugin_init_func plugin_init;
 635
 636   dl_handle = LoadLibrary (plugin->full_name);
 637   if (!dl_handle)
 638     {
 639       char *err = win32_error_msg ();
 640       error ("cannot load plugin %s\n%s", plugin->full_name, err);
 641       LocalFree (err);
 642       return false;
 643     }
 644
 645   /* Check the plugin license. Unlike the name suggests, GetProcAddress()
 646      can be used for both functions and variables.  */
 647   if (GetProcAddress (dl_handle, str_license) == NULL)
 648     {
 649       char *err = win32_error_msg ();
 650       fatal_error (input_location,
 651                    "plugin %s is not licensed under a GPL-compatible license\n"
 652                    "%s", plugin->full_name, err);
 653     }
 654
 655   /* Unlike dlsym(), GetProcAddress() returns a pointer to a function so we
 656      can cast directly without union tricks.  */
 657   plugin_init = (plugin_init_func)
 658     GetProcAddress (dl_handle, str_plugin_init_func_name);
 659
 660   if (plugin_init == NULL)
 661     {
 662       char *err = win32_error_msg ();
 663       FreeLibrary (dl_handle);
 664       error ("cannot find %s in plugin %s\n%s", str_plugin_init_func_name,
 665              plugin->full_name, err);
 666       LocalFree (err);
 667       return false;
 668     }
 669
 670   /* Call the plugin-provided initialization routine with the arguments.  */
 671   if ((*plugin_init) (plugin, &gcc_version))
 672     {
 673       FreeLibrary (dl_handle);
 674       error ("fail to initialize plugin %s", plugin->full_name);
 675       return false;
 676     }
 677   /* Leak dl_handle on purpose to ensure the plugin is loaded for the
 678      entire run of the compiler. */
 679   return true;
 680 }
 681
 682 #else // POSIX-like with dlopen()/dlsym().
 683
 684 /* We need a union to cast dlsym return value to a function pointer
 685    as ISO C forbids assignment between function pointer and 'void *'.
 686    Use explicit union instead of __extension__(<union_cast>) for
 687    portability.  */
 688 #define PTR_UNION_TYPE(TOTYPE) union { void *_q; TOTYPE _nq; }
 689 #define PTR_UNION_AS_VOID_PTR(NAME) (NAME._q)
 690 #define PTR_UNION_AS_CAST_PTR(NAME) (NAME._nq)
 691
 692 static bool
 693 try_init_one_plugin (struct plugin_name_args *plugin)
 694 {
 695   void *dl_handle;
 696   plugin_init_func plugin_init;
 697   const char *err;
 698   PTR_UNION_TYPE (plugin_init_func) plugin_init_union;
 699
 700   /* We use RTLD_NOW to accelerate binding and detect any mismatch
 701      between the API expected by the plugin and the GCC API; we use
 702      RTLD_GLOBAL which is useful to plugins which themselves call
 703      dlopen.  */
 704   dl_handle = dlopen (plugin->full_name, RTLD_NOW | RTLD_GLOBAL);
 705   if (!dl_handle)
 706     {
 707       error ("cannot load plugin %s: %s", plugin->full_name, dlerror ());
 708       return false;
 709     }
 710
 711   /* Clear any existing error.  */
 712   dlerror ();
 713
 714   /* Check the plugin license.  */
 715   if (dlsym (dl_handle, str_license) == NULL)
 716     fatal_error (input_location,
 717                  "plugin %s is not licensed under a GPL-compatible license"
 718                  " %s", plugin->full_name, dlerror ());
 719
 720   PTR_UNION_AS_VOID_PTR (plugin_init_union)
 721     = dlsym (dl_handle, str_plugin_init_func_name);
 722   plugin_init = PTR_UNION_AS_CAST_PTR (plugin_init_union);
 723
 724   if ((err = dlerror ()) != NULL)
 725     {
 726       dlclose(dl_handle);
 727       error ("cannot find %s in plugin %s: %s", str_plugin_init_func_name,
 728              plugin->full_name, err);
 729       return false;
 730     }
 731
 732   /* Call the plugin-provided initialization routine with the arguments.  */
 733   if ((*plugin_init) (plugin, &gcc_version))
 734     {
 735       dlclose(dl_handle);
 736       error ("failed to initialize plugin %s", plugin->full_name);
 737       return false;
 738     }
 739   /* leak dl_handle on purpose to ensure the plugin is loaded for the
 740      entire run of the compiler. */
 741   return true;
 742 }
 743 #endif
 744
 745 /* Routine to dlopen and initialize one plugin. This function is passed to
 746    (and called by) the hash table traverse routine. Return 1 for the
 747    htab_traverse to continue scan, 0 to stop.
 748
 749    SLOT - slot of the hash table element
 750    INFO - auxiliary pointer handed to hash table traverse routine
 751           (unused in this function)  */
 752
 753 static int
 754 init_one_plugin (void **slot, void * ARG_UNUSED (info))
 755 {
 756   struct plugin_name_args *plugin = (struct plugin_name_args *) *slot;
 757   bool ok = try_init_one_plugin (plugin);
 758   if (!ok)
 759     {
 760       htab_remove_elt_with_hash (plugin_name_args_tab, plugin->base_name,
 761                                  htab_hash_string (plugin->base_name));
 762       XDELETE (plugin);
 763     }
 764   return 1;
 765 }
 766
 767 #endif  /* ENABLE_PLUGIN  */
 768
 769 /* Main plugin initialization function.  Called from compile_file() in
 770    toplev.cc.  */
 771
 772 void
 773 initialize_plugins (void)
 774 {
 775   /* If no plugin was specified in the command-line, simply return.  */
 776   if (!plugin_name_args_tab)
 777     return;
 778
 779   timevar_push (TV_PLUGIN_INIT);
 780
 781 #ifdef ENABLE_PLUGIN
 782   /* Traverse and initialize each plugin specified in the command-line.  */
 783   htab_traverse_noresize (plugin_name_args_tab, init_one_plugin, NULL);
 784 #endif
 785
 786   timevar_pop (TV_PLUGIN_INIT);
 787 }
 788
 789 /* Release memory used by one plugin. */
 790
 791 static int
 792 finalize_one_plugin (void **slot, void * ARG_UNUSED (info))
 793 {
 794   struct plugin_name_args *plugin = (struct plugin_name_args *) *slot;
 795   XDELETE (plugin);
 796   return 1;
 797 }
 798
 799 /* Free memory allocated by the plugin system. */
 800
 801 void
 802 finalize_plugins (void)
 803 {
 804   if (!plugin_name_args_tab)
 805     return;
 806
 807   /* We can now delete the plugin_name_args object as it will no longer
 808      be used. Note that base_name and argv fields (both of which were also
 809      dynamically allocated) are not freed as they could still be used by
 810      the plugin code.  */
 811
 812   htab_traverse_noresize (plugin_name_args_tab, finalize_one_plugin, NULL);
 813
 814   /* PLUGIN_NAME_ARGS_TAB is no longer needed, just delete it.  */
 815   htab_delete (plugin_name_args_tab);
 816   plugin_name_args_tab = NULL;
 817 }
 818
 819 /* Implementation detail of for_each_plugin.  */
 820
 821 struct for_each_plugin_closure
 822 {
 823   void (*cb) (const plugin_name_args *,
 824               void *user_data);
 825   void *user_data;
 826 };
 827
 828 /* Implementation detail of for_each_plugin: callback for htab_traverse_noresize
 829    that calls the user-provided callback.  */
 830
 831 static int
 832 for_each_plugin_cb (void **slot, void *info)
 833 {
 834   struct plugin_name_args *plugin = (struct plugin_name_args *) *slot;
 835   for_each_plugin_closure *c = (for_each_plugin_closure *)info;
 836   c->cb (plugin, c->user_data);
 837   return 1;
 838 }
 839
 840 /* Call CB with USER_DATA on each plugin.  */
 841
 842 void
 843 for_each_plugin (void (*cb) (const plugin_name_args *,
 844                              void *user_data),
 845                  void *user_data)
 846 {
 847   if (!plugin_name_args_tab)
 848     return;
 849
 850   for_each_plugin_closure c;
 851   c.cb = cb;
 852   c.user_data = user_data;
 853
 854   htab_traverse_noresize (plugin_name_args_tab, for_each_plugin_cb, &c);
 855 }
 856
 857 /* Used to pass options to htab_traverse callbacks. */
 858
 859 struct print_options
 860 {
 861   FILE *file;
 862   const char *indent;
 863 };
 864
 865 /* Print the version of one plugin. */
 866
 867 static int
 868 print_version_one_plugin (void **slot, void *data)
 869 {
 870   struct print_options *opt = (struct print_options *) data;
 871   struct plugin_name_args *plugin = (struct plugin_name_args *) *slot;
 872   const char *version = plugin->version ? plugin->version : "Unknown version.";
 873
 874   fprintf (opt->file, " %s%s: %s\n", opt->indent, plugin->base_name, version);
 875   return 1;
 876 }
 877
 878 /* Print the version of each plugin. */
 879
 880 void
 881 print_plugins_versions (FILE *file, const char *indent)
 882 {
 883   struct print_options opt;
 884   opt.file = file;
 885   opt.indent = indent;
 886   if (!plugin_name_args_tab || htab_elements (plugin_name_args_tab) == 0)
 887     return;
 888
 889   fprintf (file, "%sVersions of loaded plugins:\n", indent);
 890   htab_traverse_noresize (plugin_name_args_tab, print_version_one_plugin, &opt);
 891 }
 892
 893 /* Print help for one plugin. SLOT is the hash table slot. DATA is the
 894    argument to htab_traverse_noresize. */
 895
 896 static int
 897 print_help_one_plugin (void **slot, void *data)
 898 {
 899   struct print_options *opt = (struct print_options *) data;
 900   struct plugin_name_args *plugin = (struct plugin_name_args *) *slot;
 901   const char *help = plugin->help ? plugin->help : "No help available .";
 902
 903   char *dup = xstrdup (help);
 904   char *p, *nl;
 905   fprintf (opt->file, " %s%s:\n", opt->indent, plugin->base_name);
 906
 907   for (p = nl = dup; nl; p = nl)
 908     {
 909       nl = strchr (nl, '\n');
 910       if (nl)
 911         {
 912           *nl = '\0';
 913           nl++;
 914         }
 915       fprintf (opt->file, "   %s %s\n", opt->indent, p);
 916     }
 917
 918   free (dup);
 919   return 1;
 920 }
 921
 922 /* Print help for each plugin. The output goes to FILE and every line starts
 923    with INDENT. */
 924
 925 void
 926 print_plugins_help (FILE *file, const char *indent)
 927 {
 928   struct print_options opt;
 929   opt.file = file;
 930   opt.indent = indent;
 931   if (!plugin_name_args_tab || htab_elements (plugin_name_args_tab) == 0)
 932     return;
 933
 934   fprintf (file, "%sHelp for the loaded plugins:\n", indent);
 935   htab_traverse_noresize (plugin_name_args_tab, print_help_one_plugin, &opt);
 936 }
 937
 938
 939 /* Return true if plugins have been loaded.  */
 940
 941 bool
 942 plugins_active_p (void)
 943 {
 944   int event;
 945
 946   for (event = PLUGIN_PASS_MANAGER_SETUP; event < event_last; event++)
 947     if (plugin_callbacks[event])
 948       return true;
 949
 950   return false;
 951 }
 952
 953
 954 /* Dump to FILE the names and associated events for all the active
 955    plugins.  */
 956
 957 DEBUG_FUNCTION void
 958 dump_active_plugins (FILE *file)
 959 {
 960   int event;
 961
 962   if (!plugins_active_p ())
 963     return;
 964
 965   fprintf (file, FMT_FOR_PLUGIN_EVENT " | %s\n", _("Event"), _("Plugins"));
 966   for (event = PLUGIN_PASS_MANAGER_SETUP; event < event_last; event++)
 967     if (plugin_callbacks[event])
 968       {
 969         struct callback_info *ci;
 970
 971         fprintf (file, FMT_FOR_PLUGIN_EVENT " |", plugin_event_name[event]);
 972
 973         for (ci = plugin_callbacks[event]; ci; ci = ci->next)
 974           fprintf (file, " %s", ci->plugin_name);
 975
 976         putc ('\n', file);
 977       }
 978 }
 979
 980
 981 /* Dump active plugins to stderr.  */
 982
 983 DEBUG_FUNCTION void
 984 debug_active_plugins (void)
 985 {
 986   dump_active_plugins (stderr);
 987 }
 988
 989 /* Give a warning if plugins are present, before an ICE message asking
 990    to submit a bug report.  */
 991
 992 void
 993 warn_if_plugins (void)
 994 {
 995   if (plugins_active_p ())
 996     {
 997       fnotice (stderr, "*** WARNING *** there are active plugins, do not report"
 998                " this as a bug unless you can reproduce it without enabling"
 999                " any plugins.\n");
1000       dump_active_plugins (stderr);
1001     }
1002
1003 }
1004
1005 /* The default version check. Compares every field in VERSION. */
1006
1007 bool
1008 plugin_default_version_check (struct plugin_gcc_version *gcc_version,
1009                               struct plugin_gcc_version *plugin_version)
1010 {
1011   if (!gcc_version || !plugin_version)
1012     return false;
1013
1014   if (strcmp (gcc_version->basever, plugin_version->basever))
1015     return false;
1016   if (strcmp (gcc_version->datestamp, plugin_version->datestamp))
1017     return false;
1018   if (strcmp (gcc_version->devphase, plugin_version->devphase))
1019     return false;
1020   if (strcmp (gcc_version->revision, plugin_version->revision))
1021     return false;
1022   if (strcmp (gcc_version->configuration_arguments,
1023               plugin_version->configuration_arguments))
1024     return false;
1025   return true;
1026 }
1027
1028
1029 /* Return the current value of event_last, so that plugins which provide
1030    additional functionality for events for the benefit of high-level plugins
1031    know how many valid entries plugin_event_name holds.  */
1032
1033 int
1034 get_event_last (void)
1035 {
1036   return event_last;
1037 }
1038
1039
1040 /* Retrieve the default plugin directory.  The gcc driver should have passed
1041    it as -iplugindir <dir> to the cc1 program, and it is queriable through the
1042    -print-file-name=plugin option to gcc.  */
1043 const char*
1044 default_plugin_dir_name (void)
1045 {
1046   if (!plugindir_string)
1047     fatal_error (input_location,
1048                  "%<-iplugindir%> option not passed from the gcc driver");
1049   return plugindir_string;
1050 }