1 // gold.h -- general definitions for gold   -*- C++ -*-
2 
3 // Copyright (C) 2006-2016 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 // __STDC_FORMAT_MACROS is needed to turn on macros in <inttypes.h>.
36 #define __STDC_FORMAT_MACROS
37 #include <inttypes.h>
38 
39 #include "system.h"
40 
41 namespace gold
42 {
43 
44 // General declarations.
45 
46 class General_options;
47 class Command_line;
48 class Dirsearch;
49 class Input_objects;
50 class Mapfile;
51 class Symbol;
52 class Symbol_table;
53 class Layout;
54 class Task;
55 class Workqueue;
56 class Output_file;
57 template<int size, bool big_endian>
58 struct Relocate_info;
59 
60 // Exit status codes.
61 
62 enum Exit_status
63 {
64   GOLD_OK = EXIT_SUCCESS,
65   GOLD_ERR = EXIT_FAILURE,
66   GOLD_FALLBACK = EXIT_FAILURE + 1
67 };
68 
69 // Some basic types.  For these we use lower case initial letters.
70 
71 // For an offset in an input or output file, use off_t.  Note that
72 // this will often be a 64-bit type even for a 32-bit build.
73 
74 // The size of a section if we are going to look at the contents.
75 typedef size_t section_size_type;
76 
77 // An offset within a section when we are looking at the contents.
78 typedef ptrdiff_t section_offset_type;
79 
80 // The name of the program as used in error messages.
81 extern const char* program_name;
82 
83 // This function is called to exit the program.  Status is true to
84 // exit success (0) and false to exit failure (1).
85 extern void
86 gold_exit(Exit_status status) ATTRIBUTE_NORETURN;
87 
88 // This function is called to emit an error message and then
89 // immediately exit with failure.
90 extern void
91 gold_fatal(const char* format, ...) ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_1;
92 
93 // This function is called to issue an error.  This will cause gold to
94 // eventually exit with failure.
95 extern void
96 gold_error(const char* msg, ...) ATTRIBUTE_PRINTF_1;
97 
98 // This function is called to issue a warning.
99 extern void
100 gold_warning(const char* msg, ...) ATTRIBUTE_PRINTF_1;
101 
102 // This function is called to print an informational message.
103 extern void
104 gold_info(const char* msg, ...) ATTRIBUTE_PRINTF_1;
105 
106 // This function is called to emit an error message and then
107 // immediately exit with fallback status (e.g., when
108 // --incremental-update fails and the link needs to be restarted
109 // with --incremental-full).
110 extern void
111 gold_fallback(const char* format, ...) ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_1;
112 
113 // Work around a bug in gcc 4.3.0.  http://gcc.gnu.org/PR35546 .  This
114 // can probably be removed after the bug has been fixed for a while.
115 #ifdef HAVE_TEMPLATE_ATTRIBUTES
116 #define TEMPLATE_ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF_4
117 #else
118 #define TEMPLATE_ATTRIBUTE_PRINTF_4
119 #endif
120 
121 // This function is called to issue an error at the location of a
122 // reloc.
123 template<int size, bool big_endian>
124 extern void
125 gold_error_at_location(const Relocate_info<size, big_endian>*,
126 		       size_t, off_t, const char* format, ...)
127   TEMPLATE_ATTRIBUTE_PRINTF_4;
128 
129 // This function is called to issue a warning at the location of a
130 // reloc.
131 template<int size, bool big_endian>
132 extern void
133 gold_warning_at_location(const Relocate_info<size, big_endian>*,
134 			 size_t, off_t, const char* format, ...)
135   TEMPLATE_ATTRIBUTE_PRINTF_4;
136 
137 // This function is called to report an undefined symbol without
138 // a relocation (e.g., referenced by a dynamic object).  SYM is
139 // the undefined symbol.  The file name associated with the SYM
140 // is used to print a location for the undefined symbol.
141 extern void
142 gold_undefined_symbol(const Symbol*);
143 
144 // This function is called to report an undefined symbol resulting
145 // from a relocation.  SYM is the undefined symbol.  RELINFO is the
146 // general relocation info.  RELNUM is the number of the reloc,
147 // and RELOFFSET is the reloc's offset.
148 template<int size, bool big_endian>
149 extern void
150 gold_undefined_symbol_at_location(const Symbol*,
151 		                  const Relocate_info<size, big_endian>*,
152 		                  size_t, off_t);
153 
154 // This is function is called in some cases if we run out of memory.
155 extern void
156 gold_nomem() ATTRIBUTE_NORETURN;
157 
158 // In versions of gcc before 4.3, using __FUNCTION__ in a template
159 // function can cause gcc to get confused about whether or not the
160 // function can return.  See http://gcc.gnu.org/PR30988.  Use a macro
161 // to avoid the problem.  This can be removed when we no longer need
162 // to care about gcc versions before 4.3.
163 #if defined(__GNUC__) && GCC_VERSION < 4003
164 #define FUNCTION_NAME static_cast<const char*>(__FUNCTION__)
165 #else
166 #define FUNCTION_NAME __FUNCTION__
167 #endif
168 
169 // This macro and function are used in cases which can not arise if
170 // the code is written correctly.
171 
172 #define gold_unreachable() \
173   (gold::do_gold_unreachable(__FILE__, __LINE__, FUNCTION_NAME))
174 
175 extern void do_gold_unreachable(const char*, int, const char*)
176   ATTRIBUTE_NORETURN;
177 
178 // Assertion check.
179 
180 #define gold_assert(expr) ((void)(!(expr) ? gold_unreachable(), 0 : 0))
181 
182 // Print version information.
183 extern void
184 print_version(bool print_short);
185 
186 // Get the version string.
187 extern const char*
188 get_version_string();
189 
190 // Convert numeric types without unnoticed loss of precision.
191 template<typename To, typename From>
192 inline To
convert_types(const From from)193 convert_types(const From from)
194 {
195   To to = from;
196   gold_assert(static_cast<From>(to) == from);
197   return to;
198 }
199 
200 // A common case of convert_types<>: convert to section_size_type.
201 template<typename From>
202 inline section_size_type
convert_to_section_size_type(const From from)203 convert_to_section_size_type(const From from)
204 { return convert_types<section_size_type, From>(from); }
205 
206 // Queue up the first set of tasks.
207 extern void
208 queue_initial_tasks(const General_options&,
209 		    Dirsearch&,
210 		    const Command_line&,
211 		    Workqueue*,
212 		    Input_objects*,
213 		    Symbol_table*,
214 		    Layout*,
215 		    Mapfile*);
216 
217 // Queue up the set of tasks to be done before
218 // the middle set of tasks.  Only used when garbage
219 // collection is to be done.
220 extern void
221 queue_middle_gc_tasks(const General_options&,
222                       const Task*,
223                       const Input_objects*,
224                       Symbol_table*,
225                       Layout*,
226                       Workqueue*,
227                       Mapfile*);
228 
229 // Queue up the middle set of tasks.
230 extern void
231 queue_middle_tasks(const General_options&,
232 		   const Task*,
233 		   const Input_objects*,
234 		   Symbol_table*,
235 		   Layout*,
236 		   Workqueue*,
237 		   Mapfile*);
238 
239 // Queue up the final set of tasks.
240 extern void
241 queue_final_tasks(const General_options&,
242 		  const Input_objects*,
243 		  const Symbol_table*,
244 		  Layout*,
245 		  Workqueue*,
246 		  Output_file* of);
247 
248 inline bool
is_prefix_of(const char * prefix,const char * str)249 is_prefix_of(const char* prefix, const char* str)
250 {
251   return strncmp(prefix, str, strlen(prefix)) == 0;
252 }
253 
254 const char* const cident_section_start_prefix = "__start_";
255 const char* const cident_section_stop_prefix = "__stop_";
256 
257 // Returns true if the name is a valid C identifier
258 inline bool
is_cident(const char * name)259 is_cident(const char* name)
260 {
261   return (name[strspn(name,
262 		      ("0123456789"
263 		       "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
264 		       "abcdefghijklmnopqrstuvwxyz"
265 		       "_"))]
266 	  == '\0');
267 }
268 
269 // We sometimes need to hash strings.  Ideally we should use std::tr1::hash or
270 // __gnu_cxx::hash on some systems but there is no guarantee that either
271 // one is available.  For portability, we define simple string hash functions.
272 
273 template<typename Char_type>
274 inline size_t
string_hash(const Char_type * s,size_t length)275 string_hash(const Char_type* s, size_t length)
276 {
277   // This is the hash function used by the dynamic linker for
278   // DT_GNU_HASH entries.  I compared this to a Fowler/Noll/Vo hash
279   // for a C++ program with 385,775 global symbols.  This hash
280   // function was very slightly worse.  However, it is much faster to
281   // compute.  Overall wall clock time was a win.
282   const unsigned char* p = reinterpret_cast<const unsigned char*>(s);
283   size_t h = 5381;
284   for (size_t i = 0; i < length * sizeof(Char_type); ++i)
285     h = h * 33 + *p++;
286   return h;
287 }
288 
289 // Same as above except we expect the string to be zero terminated.
290 
291 template<typename Char_type>
292 inline size_t
string_hash(const Char_type * s)293 string_hash(const Char_type* s)
294 {
295   const unsigned char* p = reinterpret_cast<const unsigned char*>(s);
296   size_t h = 5381;
297   for (size_t i = 0; s[i] != 0; ++i)
298     {
299       for (size_t j = 0; j < sizeof(Char_type); j++)
300 	h = h * 33 + *p++;
301     }
302 
303   return h;
304 }
305 
306 // Return whether STRING contains a wildcard character.  This is used
307 // to speed up matching.
308 
309 inline bool
is_wildcard_string(const char * s)310 is_wildcard_string(const char* s)
311 {
312   return strpbrk(s, "?*[") != NULL;
313 }
314 
315 } // End namespace gold.
316 
317 #endif // !defined(GOLD_GOLD_H)
318