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      1 // gold.h -- general definitions for gold   -*- C++ -*-
      2 
      3 // Copyright (C) 2006-2014 Free Software Foundation, Inc.
      4 // Written by Ian Lance Taylor <iant (at) 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 		       "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
    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)
    314