gcc/ici/plugin-loader.c

   1 /* [Legacy] environment-based interface for loading high-level plugins.
   2    Copyright (C) 2009 Free Software Foundation, Inc.
   3
   4    Contributed by Inria.
   5
   6    Authors: Grigori Fursin <grigori.fursin@inria.fr>, Cupertino Miranda
   7    <cupertinomiranda@gmail.com>, Zbigniew Chamski <zbigniew.chamski@gmail.com>.
   8
   9 This file is part of GCC.
  10
  11 GCC is free software; you can redistribute it and/or modify it under
  12 the terms of the GNU General Public License as published by the Free
  13 Software Foundation; either version 3, or (at your option) any later
  14 version.
  15
  16 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  17 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19 for more details.
  20
  21 You should have received a copy of the GNU General Public License
  22 along with GCC; see the file COPYING3.  If not see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 #include "config.h"
  26 #include "system.h"
  27 #include "coretypes.h"
  28 #include "hashtab.h"
  29 #include "toplev.h"
  30 #include "gcc.h"
  31 #include "options.h"            /* flag_ici */
  32 #include "gcc-plugin.h"
  33
  34 #include "highlev-plugin-internal.h"
  35 #include "feature-internal.h"   /* init_features() */
  36
  37 #include <dlfcn.h>
  38
  39 int ici_loaded = 0;
  40
  41 /* plugin initialization/cleanup function type */
  42 typedef void (*start_stop_func) (void);
  43
  44 typedef union {
  45   void *data_ptr;
  46   start_stop_func function_ptr;
  47   plugin_callback_func callback_ptr;
  48 } dl_symbol_t ;
  49
  50 /* pointers to initialization/cleanup functions */
  51 start_stop_func ici_plugin_start = NULL;
  52
  53 /* report any errors encountered during a dl* operation */
  54 static inline bool check_for_dlerror (void)
  55 {
  56   const char *dlError;
  57   dlError = dlerror ();
  58   if (dlError)
  59   {
  60     fprintf (stderr, "Plugin manager error: DLerror: %s ...\n", dlError);
  61     return true;
  62   }
  63   return false;
  64 }
  65
  66
  67 /* load the ICI plugin shared library file named 'dynlib_file'.
  68    Return 0 if successful, and 1 otherwise. */
  69 static int
  70 load_ici_plugin_file (char *dynlib_file)
  71 {
  72   void  *dlhandle;
  73   bool error = 0;
  74   dl_symbol_t dl_symbol;
  75
  76   if (getenv ("ICI_VERBOSE") != NULL)
  77     fprintf (stderr, "ICI: loading plugin ...\n");
  78
  79   dlhandle = dlopen (dynlib_file, RTLD_LAZY);
  80   error |= check_for_dlerror ();
  81
  82   /* assignment of data pointers to function pointers is forbidden in strict
  83      ANSI mode - use a union to work around this dlsym() issue. */
  84
  85   /* plugin initialization function */
  86   dl_symbol.data_ptr = dlsym (dlhandle, "start");
  87   ici_plugin_start = dl_symbol.function_ptr;
  88   error |= check_for_dlerror ();
  89
  90   /* plugin cleanup function */
  91   dl_symbol.data_ptr = dlsym (dlhandle, "stop");
  92   register_callback (dynlib_file, PLUGIN_FINISH, dl_symbol.callback_ptr, NULL);
  93   error |= check_for_dlerror ();
  94
  95   /* if init and cleanup functions are correctly resolverd, initialize the feature list */
  96   if (!error)
  97     init_features ();
  98
  99   return error;
 100 }
 101
 102
 103 /* load a plugin speficied by envariable ICI_PLUGIN if either -fici was
 104    given on the command line or envariable ICI_USE is set to '1'. */
 105 void load_ici_plugin (void)
 106 {
 107   char *ici_use = getenv ("ICI_USE");
 108
 109   if ((ici_use != NULL) && (ici_use[0] == '1'))
 110     flag_ici = true;
 111
 112   if (flag_ici)
 113     {
 114       char *dynlib_file = getenv ("ICI_PLUGIN");
 115       if (dynlib_file != NULL)
 116         {
 117           if ((load_ici_plugin_file (dynlib_file) == 0) && ici_plugin_start)
 118             {
 119               ici_plugin_start ();
 120               ici_loaded = 1;
 121             }
 122         }
 123       else
 124         {
 125           fprintf (stderr, "ICI error: Environment variable ICI_PLUGIN is not defined ...\n");
 126           exit (-1);
 127         }
 128     }
 129 }