gold/gold.h

   1 // gold.h -- general definitions for gold   -*- C++ -*-
   2
   3 // Copyright (C) 2006-2020 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #ifndef GOLD_GOLD_H
  24 #define GOLD_GOLD_H
  25
  26 #include "config.h"
  27 #include "ansidecl.h"
  28
  29 #include <cstddef>
  30 #include <cstdlib>
  31 #include <cstring>
  32 #include <stdint.h>
  33 #include <sys/types.h>
  34
  35 #include "system.h"
  36
  37 namespace gold
  38 {
  39
  40 // General declarations.
  41
  42 class General_options;
  43 class Command_line;
  44 class Dirsearch;
  45 class Input_objects;
  46 class Mapfile;
  47 class Symbol;
  48 class Symbol_table;
  49 class Layout;
  50 class Task;
  51 class Workqueue;
  52 class Output_file;
  53 template<int size, bool big_endian>
  54 struct Relocate_info;
  55
  56 // Exit status codes.
  57
  58 enum Exit_status
  59 {
  60   GOLD_OK = EXIT_SUCCESS,
  61   GOLD_ERR = EXIT_FAILURE,
  62   GOLD_FALLBACK = EXIT_FAILURE + 1
  63 };
  64
  65 // Some basic types.  For these we use lower case initial letters.
  66
  67 // For an offset in an input or output file, use off_t.  Note that
  68 // this will often be a 64-bit type even for a 32-bit build.
  69
  70 // The size of a section if we are going to look at the contents.
  71 typedef size_t section_size_type;
  72
  73 // An offset within a section when we are looking at the contents.
  74 typedef ptrdiff_t section_offset_type;
  75
  76 // The name of the program as used in error messages.
  77 extern const char* program_name;
  78
  79 // This function is called to exit the program.  Status is true to
  80 // exit success (0) and false to exit failure (1).
  81 extern void
  82 gold_exit(Exit_status status) ATTRIBUTE_NORETURN;
  83
  84 // This function is called to emit an error message and then
  85 // immediately exit with failure.
  86 extern void
  87 gold_fatal(const char* format, ...) ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_1;
  88
  89 // This function is called to issue an error.  This will cause gold to
  90 // eventually exit with failure.
  91 extern void
  92 gold_error(const char* msg, ...) ATTRIBUTE_PRINTF_1;
  93
  94 // This function is called to issue a warning.
  95 extern void
  96 gold_warning(const char* msg, ...) ATTRIBUTE_PRINTF_1;
  97
  98 // This function is called to print an informational message.
  99 extern void
 100 gold_info(const char* msg, ...) ATTRIBUTE_PRINTF_1;
 101
 102 // This function is called to emit an error message and then
 103 // immediately exit with fallback status (e.g., when
 104 // --incremental-update fails and the link needs to be restarted
 105 // with --incremental-full).
 106 extern void
 107 gold_fallback(const char* format, ...) ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_1;
 108
 109 // Work around a bug in gcc 4.3.0.  http://gcc.gnu.org/PR35546 .  This
 110 // can probably be removed after the bug has been fixed for a while.
 111 #ifdef HAVE_TEMPLATE_ATTRIBUTES
 112 #define TEMPLATE_ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF_4
 113 #else
 114 #define TEMPLATE_ATTRIBUTE_PRINTF_4
 115 #endif
 116
 117 // This function is called to issue an error at the location of a
 118 // reloc.
 119 template<int size, bool big_endian>
 120 extern void
 121 gold_error_at_location(const Relocate_info<size, big_endian>*,
 122                        size_t, off_t, const char* format, ...)
 123   TEMPLATE_ATTRIBUTE_PRINTF_4;
 124
 125 // This function is called to issue a warning at the location of a
 126 // reloc.
 127 template<int size, bool big_endian>
 128 extern void
 129 gold_warning_at_location(const Relocate_info<size, big_endian>*,
 130                          size_t, off_t, const char* format, ...)
 131   TEMPLATE_ATTRIBUTE_PRINTF_4;
 132
 133 // This function is called to report an undefined symbol without
 134 // a relocation (e.g., referenced by a dynamic object).  SYM is
 135 // the undefined symbol.  The file name associated with the SYM
 136 // is used to print a location for the undefined symbol.
 137 extern void
 138 gold_undefined_symbol(const Symbol*);
 139
 140 // This function is called to report an undefined symbol resulting
 141 // from a relocation.  SYM is the undefined symbol.  RELINFO is the
 142 // general relocation info.  RELNUM is the number of the reloc,
 143 // and RELOFFSET is the reloc's offset.
 144 template<int size, bool big_endian>
 145 extern void
 146 gold_undefined_symbol_at_location(const Symbol*,
 147                                   const Relocate_info<size, big_endian>*,
 148                                   size_t, off_t);
 149
 150 // This is function is called in some cases if we run out of memory.
 151 extern void
 152 gold_nomem() ATTRIBUTE_NORETURN;
 153
 154 // In versions of gcc before 4.3, using __FUNCTION__ in a template
 155 // function can cause gcc to get confused about whether or not the
 156 // function can return.  See http://gcc.gnu.org/PR30988.  Use a macro
 157 // to avoid the problem.  This can be removed when we no longer need
 158 // to care about gcc versions before 4.3.
 159 #if defined(__GNUC__) && GCC_VERSION < 4003
 160 #define FUNCTION_NAME static_cast<const char*>(__FUNCTION__)
 161 #else
 162 #define FUNCTION_NAME __FUNCTION__
 163 #endif
 164
 165 // This macro and function are used in cases which can not arise if
 166 // the code is written correctly.
 167
 168 #define gold_unreachable() \
 169   (gold::do_gold_unreachable(__FILE__, __LINE__, FUNCTION_NAME))
 170
 171 extern void do_gold_unreachable(const char*, int, const char*)
 172   ATTRIBUTE_NORETURN;
 173
 174 // Assertion check.
 175
 176 #define gold_assert(expr) ((void)(!(expr) ? gold_unreachable(), 0 : 0))
 177
 178 // Print version information.
 179 extern void
 180 print_version(bool print_short);
 181
 182 // Get the version string.
 183 extern const char*
 184 get_version_string();
 185
 186 // Convert numeric types without unnoticed loss of precision.
 187 template<typename To, typename From>
 188 inline To
 189 convert_types(const From from)
 190 {
 191   To to = from;
 192   gold_assert(static_cast<From>(to) == from);
 193   return to;
 194 }
 195
 196 // A common case of convert_types<>: convert to section_size_type.
 197 template<typename From>
 198 inline section_size_type
 199 convert_to_section_size_type(const From from)
 200 { return convert_types<section_size_type, From>(from); }
 201
 202 // Queue up the first set of tasks.
 203 extern void
 204 queue_initial_tasks(const General_options&,
 205                     Dirsearch&,
 206                     const Command_line&,
 207                     Workqueue*,
 208                     Input_objects*,
 209                     Symbol_table*,
 210                     Layout*,
 211                     Mapfile*);
 212
 213 // Queue up the set of tasks to be done before
 214 // the middle set of tasks.  Only used when garbage
 215 // collection is to be done.
 216 extern void
 217 queue_middle_gc_tasks(const General_options&,
 218                       const Task*,
 219                       const Input_objects*,
 220                       Symbol_table*,
 221                       Layout*,
 222                       Workqueue*,
 223                       Mapfile*);
 224
 225 // Queue up the middle set of tasks.
 226 extern void
 227 queue_middle_tasks(const General_options&,
 228                    const Task*,
 229                    const Input_objects*,
 230                    Symbol_table*,
 231                    Layout*,
 232                    Workqueue*,
 233                    Mapfile*);
 234
 235 // Queue up the final set of tasks.
 236 extern void
 237 queue_final_tasks(const General_options&,
 238                   const Input_objects*,
 239                   const Symbol_table*,
 240                   Layout*,
 241                   Workqueue*,
 242                   Output_file* of);
 243
 244 inline bool
 245 is_prefix_of(const char* prefix, const char* str)
 246 {
 247   return strncmp(prefix, str, strlen(prefix)) == 0;
 248 }
 249
 250 const char* const cident_section_start_prefix = "__start_";
 251 const char* const cident_section_stop_prefix = "__stop_";
 252
 253 // Returns true if the name is a valid C identifier
 254 inline bool
 255 is_cident(const char* name)
 256 {
 257   return (name[strspn(name,
 258                       ("0123456789"
 259                        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 260                        "abcdefghijklmnopqrstuvwxyz"
 261                        "_"))]
 262           == '\0');
 263 }
 264
 265 // We sometimes need to hash strings.  Ideally we should use std::tr1::hash or
 266 // __gnu_cxx::hash on some systems but there is no guarantee that either
 267 // one is available.  For portability, we define simple string hash functions.
 268
 269 template<typename Char_type>
 270 inline size_t
 271 string_hash(const Char_type* s, size_t length)
 272 {
 273   // This is the hash function used by the dynamic linker for
 274   // DT_GNU_HASH entries.  I compared this to a Fowler/Noll/Vo hash
 275   // for a C++ program with 385,775 global symbols.  This hash
 276   // function was very slightly worse.  However, it is much faster to
 277   // compute.  Overall wall clock time was a win.
 278   const unsigned char* p = reinterpret_cast<const unsigned char*>(s);
 279   size_t h = 5381;
 280   for (size_t i = 0; i < length * sizeof(Char_type); ++i)
 281     h = h * 33 + *p++;
 282   return h;
 283 }
 284
 285 // Same as above except we expect the string to be zero terminated.
 286
 287 template<typename Char_type>
 288 inline size_t
 289 string_hash(const Char_type* s)
 290 {
 291   const unsigned char* p = reinterpret_cast<const unsigned char*>(s);
 292   size_t h = 5381;
 293   for (size_t i = 0; s[i] != 0; ++i)
 294     {
 295       for (size_t j = 0; j < sizeof(Char_type); j++)
 296         h = h * 33 + *p++;
 297     }
 298
 299   return h;
 300 }
 301
 302 // Return whether STRING contains a wildcard character.  This is used
 303 // to speed up matching.
 304
 305 inline bool
 306 is_wildcard_string(const char* s)
 307 {
 308   return strpbrk(s, "?*[") != NULL;
 309 }
 310
 311 } // End namespace gold.
 312
 313 #endif // !defined(GOLD_GOLD_H)