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28f540f4 RM |
1 | /* Support macros for making weak and strong aliases for symbols, |
2 | and for using symbol sets and linker warnings with GNU ld. | |
7969407a | 3 | Copyright (C) 1995-1998,2000,2001,2002 Free Software Foundation, Inc. |
5290baf0 | 4 | This file is part of the GNU C Library. |
28f540f4 | 5 | |
5290baf0 | 6 | The GNU C Library is free software; you can redistribute it and/or |
41bdb6e2 AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
28f540f4 | 10 | |
5290baf0 UD |
11 | The GNU C Library 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 GNU | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
28f540f4 | 15 | |
41bdb6e2 AJ |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, write to the Free | |
18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
19 | 02111-1307 USA. */ | |
28f540f4 RM |
20 | |
21 | #ifndef _LIBC_SYMBOLS_H | |
5290baf0 | 22 | #define _LIBC_SYMBOLS_H 1 |
28f540f4 RM |
23 | |
24 | /* This file's macros are included implicitly in the compilation of every | |
25 | file in the C library by -imacros. | |
26 | ||
27 | We include config.h which is generated by configure. | |
28 | It should define for us the following symbols: | |
29 | ||
c224a18a RM |
30 | * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'. |
31 | * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'. | |
b88ac073 RM |
32 | * ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type, |
33 | or leave it undefined if there is no .type directive. | |
28f540f4 RM |
34 | * HAVE_GNU_LD if using GNU ld, with support for weak symbols in a.out, |
35 | and for symbol set and warning messages extensions in a.out and ELF. | |
c224a18a RM |
36 | * HAVE_ELF if using ELF, which supports weak symbols using `.weak'. |
37 | * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'. | |
38 | * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'. | |
28f540f4 RM |
39 | |
40 | */ | |
28f540f4 | 41 | |
92777700 RM |
42 | /* This is defined for the compilation of all C library code. features.h |
43 | tests this to avoid inclusion of stubs.h while compiling the library, | |
44 | before stubs.h has been generated. Some library code that is shared | |
45 | with other packages also tests this symbol to see if it is being | |
46 | compiled as part of the C library. We must define this before including | |
47 | config.h, because it makes some definitions conditional on whether libc | |
48 | itself is being compiled, or just some generator program. */ | |
c709e372 | 49 | #define _LIBC 1 |
92777700 | 50 | |
d3669add RM |
51 | /* Enable declarations of GNU extensions, since we are compiling them. */ |
52 | #define _GNU_SOURCE 1 | |
ec4b0518 UD |
53 | /* And we also need the data for the reentrant functions. */ |
54 | #define _REENTRANT 1 | |
d3669add | 55 | |
92777700 | 56 | #include <config.h> |
28f540f4 | 57 | |
c224a18a RM |
58 | /* The symbols in all the user (non-_) macros are C symbols. |
59 | HAVE_GNU_LD without HAVE_ELF implies a.out. */ | |
28f540f4 | 60 | |
dfd2257a UD |
61 | #if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE |
62 | # define HAVE_WEAK_SYMBOLS | |
28f540f4 | 63 | #endif |
28f540f4 RM |
64 | |
65 | #ifndef __SYMBOL_PREFIX | |
dfd2257a UD |
66 | # ifdef NO_UNDERSCORES |
67 | # define __SYMBOL_PREFIX | |
68 | # else | |
69 | # define __SYMBOL_PREFIX "_" | |
70 | # endif | |
28f540f4 RM |
71 | #endif |
72 | ||
73 | #ifndef C_SYMBOL_NAME | |
dfd2257a UD |
74 | # ifdef NO_UNDERSCORES |
75 | # define C_SYMBOL_NAME(name) name | |
76 | # else | |
77 | # define C_SYMBOL_NAME(name) _##name | |
78 | # endif | |
28f540f4 RM |
79 | #endif |
80 | ||
b15cb495 UD |
81 | #ifndef ASM_LINE_SEP |
82 | # define ASM_LINE_SEP ; | |
83 | #endif | |
84 | ||
c843e065 RM |
85 | #ifdef HAVE_ASM_GLOBAL_DOT_NAME |
86 | # ifndef C_SYMBOL_DOT_NAME | |
87 | # if defined __GNUC__ && defined __GNUC_MINOR__ \ | |
88 | && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1 | |
89 | # define C_SYMBOL_DOT_NAME(name) .name | |
90 | # else | |
91 | # define C_SYMBOL_DOT_NAME(name) .##name | |
92 | # endif | |
93 | # endif | |
256ba888 UD |
94 | #endif |
95 | ||
428383e8 UD |
96 | #ifndef __ASSEMBLER__ |
97 | /* GCC understands weak symbols and aliases; use its interface where | |
98 | possible, instead of embedded assembly language. */ | |
d02907df | 99 | |
428383e8 | 100 | /* Define ALIASNAME as a strong alias for NAME. */ |
c62f5cab GM |
101 | # define strong_alias(name, aliasname) _strong_alias(name, aliasname) |
102 | # define _strong_alias(name, aliasname) \ | |
428383e8 UD |
103 | extern __typeof (name) aliasname __attribute__ ((alias (#name))); |
104 | ||
105 | /* This comes between the return type and function name in | |
106 | a function definition to make that definition weak. */ | |
107 | # define weak_function __attribute__ ((weak)) | |
108 | # define weak_const_function __attribute__ ((weak, __const__)) | |
109 | ||
110 | # ifdef HAVE_WEAK_SYMBOLS | |
111 | ||
112 | /* Define ALIASNAME as a weak alias for NAME. | |
113 | If weak aliases are not available, this defines a strong alias. */ | |
c62f5cab GM |
114 | # define weak_alias(name, aliasname) _weak_alias (name, aliasname) |
115 | # define _weak_alias(name, aliasname) \ | |
428383e8 UD |
116 | extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))); |
117 | ||
118 | /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ | |
ebdf53a7 | 119 | # define weak_extern(symbol) _weak_extern (symbol) |
428383e8 | 120 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE |
c843e065 RM |
121 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
122 | # define _weak_extern(symbol) \ | |
123 | asm (".weakext " __SYMBOL_PREFIX #symbol "\n\t" \ | |
124 | ".weakext ." __SYMBOL_PREFIX #symbol); | |
125 | # else | |
126 | # define _weak_extern(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol); | |
127 | # endif | |
428383e8 | 128 | # else |
c843e065 RM |
129 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
130 | # define _weak_extern(symbol) \ | |
131 | asm (".weak " __SYMBOL_PREFIX #symbol "\n\t" \ | |
132 | ".weak ." __SYMBOL_PREFIX #symbol); | |
133 | # else | |
134 | # define _weak_extern(symbol) asm (".weak " __SYMBOL_PREFIX #symbol); | |
135 | # endif | |
428383e8 UD |
136 | # endif |
137 | ||
138 | # else | |
139 | ||
140 | # define weak_alias(name, aliasname) strong_alias(name, aliasname) | |
141 | # define weak_extern(symbol) /* Nothing. */ | |
142 | ||
143 | # endif | |
144 | ||
145 | #else /* __ASSEMBLER__ */ | |
146 | ||
147 | # ifdef HAVE_ASM_SET_DIRECTIVE | |
c843e065 RM |
148 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
149 | # define strong_alias(original, alias) \ | |
150 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
151 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
152 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
153 | .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original) | |
154 | # define strong_data_alias(original, alias) \ | |
155 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
28f540f4 | 156 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) |
c843e065 RM |
157 | # else |
158 | # define strong_alias(original, alias) \ | |
159 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
160 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) | |
161 | # define strong_data_alias(original, alias) strong_alias(original, alias) | |
162 | # endif | |
dfd2257a | 163 | # else |
2aa15430 | 164 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 RM |
165 | # define strong_alias(original, alias) \ |
166 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
167 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
168 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
2aa15430 | 169 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) |
c843e065 RM |
170 | # define strong_data_alias(original, alias) \ |
171 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
172 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) | |
2aa15430 | 173 | # else |
c843e065 RM |
174 | # define strong_alias(original, alias) \ |
175 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
335aa320 | 176 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
c843e065 | 177 | # define strong_data_alias(original, alias) strong_alias(original, alias) |
2aa15430 | 178 | # endif |
dfd2257a | 179 | # endif |
d02907df | 180 | |
428383e8 | 181 | # ifdef HAVE_WEAK_SYMBOLS |
dfd2257a | 182 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE |
c843e065 RM |
183 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
184 | # define weak_alias(original, alias) \ | |
185 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
186 | .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) | |
187 | # else | |
188 | # define weak_alias(original, alias) \ | |
c224a18a | 189 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) |
c843e065 RM |
190 | # endif |
191 | # define weak_extern(symbol) \ | |
af5b3bc3 | 192 | .weakext C_SYMBOL_NAME (symbol) |
c224a18a | 193 | |
dfd2257a | 194 | # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ |
c224a18a | 195 | |
2aa15430 | 196 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 RM |
197 | # define weak_alias(original, alias) \ |
198 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
199 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
200 | .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
2aa15430 UD |
201 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) |
202 | # else | |
c843e065 RM |
203 | # define weak_alias(original, alias) \ |
204 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
28f540f4 | 205 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
2aa15430 | 206 | # endif |
e6964dd4 | 207 | |
c843e065 | 208 | # define weak_extern(symbol) \ |
af5b3bc3 | 209 | .weak C_SYMBOL_NAME (symbol) |
d02907df | 210 | |
dfd2257a | 211 | # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ |
c224a18a | 212 | |
428383e8 | 213 | # else /* ! HAVE_WEAK_SYMBOLS */ |
af5b3bc3 | 214 | |
428383e8 UD |
215 | # define weak_alias(original, alias) strong_alias(original, alias) |
216 | # define weak_extern(symbol) /* Nothing */ | |
217 | # endif /* ! HAVE_WEAK_SYMBOLS */ | |
af5b3bc3 | 218 | |
428383e8 | 219 | #endif /* __ASSEMBLER__ */ |
958f803f | 220 | |
dfd2257a UD |
221 | /* On some platforms we can make internal function calls (i.e., calls of |
222 | functions not exported) a bit faster by using a different calling | |
223 | convention. */ | |
224 | #ifndef internal_function | |
225 | # define internal_function /* empty */ | |
226 | #endif | |
28f540f4 | 227 | |
a8eab8b1 UD |
228 | /* Prepare for the case that `__builtin_expect' is not available. */ |
229 | #ifndef HAVE_BUILTIN_EXPECT | |
230 | # define __builtin_expect(expr, val) (expr) | |
231 | #endif | |
232 | ||
e862aada UD |
233 | /* Determine the return address. */ |
234 | #define RETURN_ADDRESS(nr) \ | |
235 | __builtin_extract_return_addr (__builtin_return_address (nr)) | |
236 | ||
44c8d1a2 RM |
237 | /* When a reference to SYMBOL is encountered, the linker will emit a |
238 | warning message MSG. */ | |
28f540f4 | 239 | #ifdef HAVE_GNU_LD |
dfd2257a | 240 | # ifdef HAVE_ELF |
fd26970f UD |
241 | |
242 | /* We want the .gnu.warning.SYMBOL section to be unallocated. */ | |
dfd2257a UD |
243 | # ifdef HAVE_ASM_PREVIOUS_DIRECTIVE |
244 | # define __make_section_unallocated(section_string) \ | |
b15cb495 | 245 | asm (".section " section_string "\n\t.previous"); |
e26dd47f | 246 | # elif defined HAVE_ASM_POPSECTION_DIRECTIVE |
dfd2257a | 247 | # define __make_section_unallocated(section_string) \ |
b15cb495 | 248 | asm (".pushsection " section_string "\n\t.popsection"); |
dfd2257a UD |
249 | # else |
250 | # define __make_section_unallocated(section_string) | |
251 | # endif | |
fd26970f | 252 | |
b15cb495 UD |
253 | /* Tacking on "\n\t#" to the section name makes gcc put it's bogus |
254 | section attributes on what looks like a comment to the assembler. */ | |
e26dd47f UD |
255 | # ifdef HAVE_SECTION_QUOTES |
256 | # define link_warning(symbol, msg) \ | |
257 | __make_section_unallocated (".gnu.warning." #symbol) \ | |
258 | static const char __evoke_link_warning_##symbol[] \ | |
13176c60 RM |
259 | __attribute__ ((unused, section (".gnu.warning." #symbol "\"\n\t#\""))) \ |
260 | = msg; | |
e26dd47f UD |
261 | # else |
262 | # define link_warning(symbol, msg) \ | |
263 | __make_section_unallocated (".gnu.warning." #symbol) \ | |
44c8d1a2 | 264 | static const char __evoke_link_warning_##symbol[] \ |
13176c60 | 265 | __attribute__ ((unused, section (".gnu.warning." #symbol "\n\t#"))) = msg; |
e26dd47f | 266 | # endif |
5af3245a UD |
267 | # else /* Not ELF: a.out */ |
268 | # ifdef HAVE_XCOFF | |
269 | /* XCOFF does not support .stabs. | |
270 | The native aix linker will remove the .stab and .stabstr sections | |
271 | The gnu linker will have a fatal error if there is a relocation for | |
272 | symbol in the .stab section. Silently disable this macro. */ | |
7969407a | 273 | # define link_warning(symbol, msg) |
5af3245a UD |
274 | # else |
275 | # define link_warning(symbol, msg) \ | |
276 | asm (".stabs \"" msg "\",30,0,0,0\n\t" \ | |
277 | ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n"); | |
278 | # endif /* XCOFF */ | |
dfd2257a | 279 | # endif |
28f540f4 RM |
280 | #else |
281 | /* We will never be heard; they will all die horribly. */ | |
dfd2257a | 282 | # define link_warning(symbol, msg) |
28f540f4 RM |
283 | #endif |
284 | ||
285 | /* A canned warning for sysdeps/stub functions. */ | |
286 | #define stub_warning(name) \ | |
44c8d1a2 RM |
287 | link_warning (name, \ |
288 | "warning: " #name " is not implemented and will always fail") | |
5f9e57ba | 289 | |
b88ac073 RM |
290 | |
291 | /* Declare SYMBOL to be TYPE (`function' or `object') and of SIZE bytes, | |
292 | when the assembler supports such declarations (such as in ELF). | |
293 | This is only necessary when defining something in assembly, or playing | |
294 | funny alias games where the size should be other than what the compiler | |
295 | thinks it is. */ | |
296 | #define declare_symbol(symbol, type, size) \ | |
297 | declare_symbol_1 (symbol, type, size) | |
298 | #ifdef ASM_TYPE_DIRECTIVE_PREFIX | |
299 | # ifdef __ASSEMBLER__ | |
300 | # define declare_symbol_1(symbol, type, size) \ | |
301 | .type C_SYMBOL_NAME (symbol), \ | |
302 | declare_symbol_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type), size | |
303 | # define declare_symbol_1_paste(a, b) declare_symbol_1_paste_1 (a,b) | |
304 | # define declare_symbol_1_paste_1(a,b) a##b | |
305 | # else /* Not __ASSEMBLER__. */ | |
306 | # define declare_symbol_1(symbol, type, size) \ | |
9e7f59b4 | 307 | asm (".type " __SYMBOL_PREFIX #symbol ", " \ |
b88ac073 RM |
308 | declare_symbol_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \ |
309 | "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size); | |
310 | # define declare_symbol_1_stringify(x) declare_symbol_1_stringify_1 (x) | |
311 | # define declare_symbol_1_stringify_1(x) #x | |
312 | # endif /* __ASSEMBLER__ */ | |
313 | #else | |
314 | # define declare_symbol_1(symbol, type, size) /* Nothing. */ | |
315 | #endif | |
316 | ||
317 | ||
5f9e57ba | 318 | /* |
28f540f4 | 319 | \f |
5f9e57ba RM |
320 | */ |
321 | ||
28f540f4 RM |
322 | #ifdef HAVE_GNU_LD |
323 | ||
324 | /* Symbol set support macros. */ | |
325 | ||
dfd2257a | 326 | # ifdef HAVE_ELF |
28f540f4 RM |
327 | |
328 | /* Make SYMBOL, which is in the text segment, an element of SET. */ | |
dfd2257a | 329 | # define text_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 | 330 | /* Make SYMBOL, which is in the data segment, an element of SET. */ |
dfd2257a | 331 | # define data_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 | 332 | /* Make SYMBOL, which is in the bss segment, an element of SET. */ |
dfd2257a | 333 | # define bss_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 RM |
334 | |
335 | /* These are all done the same way in ELF. | |
336 | There is a new section created for each set. */ | |
b5567b2a | 337 | # ifdef SHARED |
53afa8d9 RM |
338 | /* When building a shared library, make the set section writable, |
339 | because it will need to be relocated at run time anyway. */ | |
dfd2257a | 340 | # define _elf_set_element(set, symbol) \ |
53afa8d9 | 341 | static const void *__elf_set_##set##_element_##symbol##__ \ |
d6e2f671 | 342 | __attribute__ ((unused, section (#set))) = &(symbol) |
dfd2257a UD |
343 | # else |
344 | # define _elf_set_element(set, symbol) \ | |
28f540f4 | 345 | static const void *const __elf_set_##set##_element_##symbol##__ \ |
d6e2f671 | 346 | __attribute__ ((unused, section (#set))) = &(symbol) |
dfd2257a | 347 | # endif |
28f540f4 RM |
348 | |
349 | /* Define SET as a symbol set. This may be required (it is in a.out) to | |
350 | be able to use the set's contents. */ | |
dfd2257a | 351 | # define symbol_set_define(set) symbol_set_declare(set) |
28f540f4 RM |
352 | |
353 | /* Declare SET for use in this module, if defined in another module. */ | |
dfd2257a | 354 | # define symbol_set_declare(set) \ |
03df72bf GM |
355 | extern void *const __start_##set __attribute__ ((__weak__)); \ |
356 | extern void *const __stop_##set __attribute__ ((__weak__)); \ | |
af5b3bc3 | 357 | weak_extern (__start_##set) weak_extern (__stop_##set) |
28f540f4 RM |
358 | |
359 | /* Return a pointer (void *const *) to the first element of SET. */ | |
dfd2257a | 360 | # define symbol_set_first_element(set) (&__start_##set) |
28f540f4 RM |
361 | |
362 | /* Return true iff PTR (a void *const *) has been incremented | |
363 | past the last element in SET. */ | |
dfd2257a | 364 | # define symbol_set_end_p(set, ptr) ((ptr) >= &__stop_##set) |
28f540f4 | 365 | |
dfd2257a | 366 | # else /* Not ELF: a.out. */ |
28f540f4 | 367 | |
5af3245a UD |
368 | # ifdef HAVE_XCOFF |
369 | /* XCOFF does not support .stabs. | |
370 | The native aix linker will remove the .stab and .stabstr sections | |
371 | The gnu linker will have a fatal error if there is a relocation for | |
372 | symbol in the .stab section. Silently disable these macros. */ | |
7969407a UD |
373 | # define text_set_element(set, symbol) |
374 | # define data_set_element(set, symbol) | |
375 | # define bss_set_element(set, symbol) | |
5af3245a UD |
376 | # else |
377 | # define text_set_element(set, symbol) \ | |
378 | asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol) | |
379 | # define data_set_element(set, symbol) \ | |
380 | asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol) | |
381 | # define bss_set_element(set, symbol) ?error Must use initialized data. | |
382 | # endif /* XCOFF */ | |
dfd2257a | 383 | # define symbol_set_define(set) void *const (set)[1]; |
03df72bf | 384 | # define symbol_set_declare(set) extern void *const (set)[1]; |
28f540f4 | 385 | |
dfd2257a UD |
386 | # define symbol_set_first_element(set) &(set)[1] |
387 | # define symbol_set_end_p(set, ptr) (*(ptr) == 0) | |
28f540f4 | 388 | |
dfd2257a | 389 | # endif /* ELF. */ |
a2a89dd6 UD |
390 | #else |
391 | /* We cannot do anything in generial. */ | |
392 | # define text_set_element(set, symbol) asm ("") | |
393 | # define data_set_element(set, symbol) asm ("") | |
394 | # define bss_set_element(set, symbol) asm ("") | |
395 | # define symbol_set_define(set) void *const (set)[1]; | |
396 | # define symbol_set_declare(set) extern void *const (set)[1]; | |
397 | ||
398 | # define symbol_set_first_element(set) &(set)[1] | |
399 | # define symbol_set_end_p(set, ptr) (*(ptr) == 0) | |
28f540f4 RM |
400 | #endif /* Have GNU ld. */ |
401 | ||
1ea89a40 | 402 | #if DO_VERSIONING |
ebdf53a7 | 403 | # define symbol_version(real, name, version) \ |
8b943b4a | 404 | _symbol_version(real, name, version) |
ebdf53a7 GM |
405 | # define default_symbol_version(real, name, version) \ |
406 | _default_symbol_version(real, name, version) | |
407 | # ifdef __ASSEMBLER__ | |
c843e065 RM |
408 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
409 | # define _symbol_version(real, name, version) \ | |
410 | .symver real, name##@##version ASM_LINE_SEP \ | |
411 | .symver .##real, .##name##@##version | |
412 | # define _default_symbol_version(real, name, version) \ | |
413 | .symver real, name##@##@##version ASM_LINE_SEP \ | |
414 | .symver .##real, .##name##@##@##version | |
415 | # else | |
416 | # define _symbol_version(real, name, version) \ | |
da2d1bc5 | 417 | .symver real, name##@##version |
c843e065 | 418 | # define _default_symbol_version(real, name, version) \ |
da2d1bc5 | 419 | .symver real, name##@##@##version |
c843e065 | 420 | # endif |
da2d1bc5 | 421 | # else |
c843e065 RM |
422 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
423 | # define _symbol_version(real, name, version) \ | |
424 | __asm__ (".symver " #real "," #name "@" #version "\n\t" \ | |
425 | ".symver ." #real ",." #name "@" #version) | |
426 | # define _default_symbol_version(real, name, version) \ | |
427 | __asm__ (".symver " #real "," #name "@@" #version "\n\t" \ | |
428 | ".symver ." #real ",." #name "@@" #version) | |
429 | # else | |
430 | # define _symbol_version(real, name, version) \ | |
1ea89a40 | 431 | __asm__ (".symver " #real "," #name "@" #version) |
c843e065 | 432 | # define _default_symbol_version(real, name, version) \ |
f2ea0f5b | 433 | __asm__ (".symver " #real "," #name "@@" #version) |
c843e065 | 434 | # endif |
da2d1bc5 | 435 | # endif |
1ea89a40 UD |
436 | #else |
437 | # define symbol_version(real, name, version) | |
da2d1bc5 UD |
438 | # define default_symbol_version(real, name, version) \ |
439 | strong_alias(real, name) | |
1ea89a40 UD |
440 | #endif |
441 | ||
e6caf4e1 UD |
442 | #if defined HAVE_VISIBILITY_ATTRIBUTE && defined SHARED |
443 | # define attribute_hidden __attribute__ ((visibility ("hidden"))) | |
444 | #else | |
445 | # define attribute_hidden | |
446 | #endif | |
447 | ||
7969407a UD |
448 | /* Handling on non-exported internal names. We have to do this only |
449 | for shared code. */ | |
450 | #ifdef SHARED | |
cff26a3e | 451 | # define INTUSE(name) name##_internal |
e6caf4e1 UD |
452 | # define INTDEF(name) strong_alias (name, name##_internal) |
453 | # define INTVARDEF(name) \ | |
1897bc3f | 454 | _INTVARDEF (name, name##_internal) |
7f0244de AJ |
455 | # if defined HAVE_VISIBILITY_ATTRIBUTE |
456 | # define _INTVARDEF(name, aliasname) \ | |
100351c3 UD |
457 | extern __typeof (name) aliasname __attribute__ ((alias (#name), \ |
458 | visibility ("hidden"))); | |
7f0244de AJ |
459 | # else |
460 | # define _INTVARDEF(name, aliasname) \ | |
461 | extern __typeof (name) aliasname __attribute__ ((alias (#name))); | |
462 | # endif | |
e6caf4e1 | 463 | # define INTDEF2(name, newname) strong_alias (name, newname##_internal) |
1897bc3f | 464 | # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal) |
7969407a | 465 | #else |
cff26a3e | 466 | # define INTUSE(name) name |
7969407a | 467 | # define INTDEF(name) |
e6caf4e1 | 468 | # define INTVARDEF(name) |
77fe0b9c | 469 | # define INTDEF2(name, newname) |
1897bc3f | 470 | # define INTVARDEF2(name, newname) |
7969407a UD |
471 | #endif |
472 | ||
37ba7d66 UD |
473 | /* The following macros are used for PLT bypassing within libc.so |
474 | (and if needed other libraries similarly). | |
475 | First of all, you need to have the function prototyped somewhere, | |
476 | say in foo/foo.h: | |
477 | ||
478 | int foo (int __bar); | |
479 | ||
480 | If calls to foo within libc.so should always go to foo defined in libc.so, | |
481 | then in include/foo.h you add: | |
482 | ||
483 | libc_hidden_proto (foo) | |
484 | ||
485 | line and after the foo function definition: | |
486 | ||
487 | int foo (int __bar) | |
488 | { | |
489 | return __bar; | |
490 | } | |
491 | libc_hidden_def (foo) | |
492 | ||
493 | or | |
494 | ||
495 | int foo (int __bar) | |
496 | { | |
497 | return __bar; | |
498 | } | |
499 | libc_hidden_weak (foo) | |
500 | ||
c843e065 RM |
501 | Simularly for global data. If references to foo within libc.so should |
502 | always go to foo defined in libc.so, then in include/foo.h you add: | |
503 | ||
504 | libc_hidden_proto (foo) | |
505 | ||
506 | line and after foo's definition: | |
507 | ||
508 | int foo = INITIAL_FOO_VALUE; | |
509 | libc_hidden_data_def (foo) | |
510 | ||
511 | or | |
512 | ||
513 | int foo = INITIAL_FOO_VALUE; | |
514 | libc_hidden_data_weak (foo) | |
515 | ||
37ba7d66 UD |
516 | If foo is normally just an alias (strong or weak) of some other function, |
517 | you should use the normal strong_alias first, then add libc_hidden_def | |
518 | or libc_hidden_weak: | |
519 | ||
520 | int baz (int __bar) | |
521 | { | |
522 | return __bar; | |
523 | } | |
524 | strong_alias (baz, foo) | |
525 | libc_hidden_weak (foo) | |
526 | ||
527 | If the function should be internal to multiple objects, say ld.so and | |
528 | libc.so, the best way is to use: | |
529 | ||
530 | #if !defined NOT_IN_libc || defined IS_IN_rtld | |
531 | hidden_proto (foo) | |
532 | #endif | |
533 | ||
534 | in include/foo.h and the normal macros at all function definitions | |
535 | depending on what DSO they belong to. | |
536 | ||
537 | If versioned_symbol macro is used to define foo, | |
538 | libc_hidden_ver macro should be used, as in: | |
539 | ||
540 | int __real_foo (int __bar) | |
541 | { | |
542 | return __bar; | |
543 | } | |
544 | versioned_symbol (libc, __real_foo, foo, GLIBC_2_1); | |
545 | libc_hidden_ver (__real_foo, foo) */ | |
546 | ||
2b29b5ac UD |
547 | #if defined SHARED && defined DO_VERSIONING \ |
548 | && !defined HAVE_BROKEN_ALIAS_ATTRIBUTE | |
37ba7d66 | 549 | # ifndef __ASSEMBLER__ |
81cb0d82 UD |
550 | # if !defined HAVE_VISIBILITY_ATTRIBUTE \ |
551 | || defined HAVE_BROKEN_VISIBILITY_ATTRIBUTE | |
552 | # define __hidden_proto_hiddenattr(attrs...) | |
37ba7d66 | 553 | # else |
81cb0d82 UD |
554 | # define __hidden_proto_hiddenattr(attrs...) \ |
555 | __attribute__ ((visibility ("hidden"), ##attrs)) | |
37ba7d66 | 556 | # endif |
81cb0d82 UD |
557 | # define hidden_proto(name, attrs...) \ |
558 | __hidden_proto (name, __GI_##name, ##attrs) | |
559 | # define __hidden_proto(name, internal, attrs...) \ | |
a585ba22 RM |
560 | extern __typeof (name) internal; \ |
561 | extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \ | |
81cb0d82 | 562 | __hidden_proto_hiddenattr (attrs); |
37ba7d66 UD |
563 | # define __hidden_asmname(name) \ |
564 | __hidden_asmname1 (__USER_LABEL_PREFIX__, name) | |
565 | # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name) | |
566 | # define __hidden_asmname2(prefix, name) #prefix name | |
567 | # ifdef HAVE_ASM_SET_DIRECTIVE | |
568 | # define __hidden_def1(original, alias) \ | |
569 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
570 | .set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) | |
37ba7d66 | 571 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 | 572 | # define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ |
37ba7d66 | 573 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ |
c843e065 | 574 | .set C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) |
37ba7d66 | 575 | # else |
c843e065 RM |
576 | # define __hidden_dot_def1(original, alias) |
577 | # endif | |
578 | # else | |
579 | # define __hidden_def1(original, alias) \ | |
37ba7d66 UD |
580 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
581 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) | |
c843e065 RM |
582 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
583 | # define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ | |
584 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
585 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) | |
586 | # else | |
d7abce98 | 587 | # define __hidden_dot_def1(original, alias) |
37ba7d66 UD |
588 | # endif |
589 | # endif | |
590 | # define __hidden_def2(...) #__VA_ARGS__ | |
591 | # define __hidden_def3(...) __hidden_def2 (__VA_ARGS__) | |
592 | # define hidden_def(name) \ | |
c843e065 RM |
593 | __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name) \ |
594 | __hidden_dot_def1 (__GI_##name, name))); | |
595 | # define hidden_data_def(name) \ | |
37ba7d66 UD |
596 | __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name))); |
597 | # define hidden_ver(local, name) \ | |
c843e065 RM |
598 | __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name) \ |
599 | __hidden_dot_def1 (local, __GI_##name))); | |
600 | # define hidden_data_ver(local, name) \ | |
37ba7d66 UD |
601 | __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name))); |
602 | # ifdef HAVE_WEAK_SYMBOLS | |
603 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE | |
604 | # define __hidden_weak1(original, alias) \ | |
605 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) | |
37ba7d66 | 606 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 RM |
607 | # define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ |
608 | .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) | |
609 | # else | |
610 | # define __hidden_dot_weak1(original, alias) | |
611 | # endif | |
612 | # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ | |
613 | # define __hidden_weak1(original, alias) \ | |
37ba7d66 | 614 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
c843e065 RM |
615 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
616 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME | |
617 | # define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ | |
37ba7d66 UD |
618 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ |
619 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) | |
620 | # else | |
c843e065 | 621 | # define __hidden_dot_weak1(original, alias) |
37ba7d66 UD |
622 | # endif |
623 | # endif | |
624 | # define hidden_weak(name) \ | |
c843e065 RM |
625 | __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name) \ |
626 | __hidden_dot_weak1 (__GI_##name, name))); | |
627 | # define hidden_data_weak(name) \ | |
37ba7d66 UD |
628 | __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name))); |
629 | # else | |
630 | # define hidden_weak(name) hidden_def (name) | |
631 | # endif | |
632 | # else | |
633 | /* For assembly, we need to do the opposite of what we do in C: | |
634 | in assembly gcc __REDIRECT stuff is not in place, so functions | |
635 | are defined by its normal name and we need to create the | |
636 | __GI_* alias to it, in C __REDIRECT causes the function definition | |
637 | to use __GI_* name and we need to add alias to the real name. | |
4547dee3 RM |
638 | There is no reason to use hidden_weak over hidden_def in assembly, |
639 | but we provide it for consistency with the C usage. | |
640 | hidden_proto doesn't make sense for assembly but the equivalent | |
641 | is to call via the HIDDEN_JUMPTARGET macro einstead of JUMPTARGET. */ | |
642 | # define hidden_def(name) strong_alias (name, __GI_##name) | |
643 | # define hidden_weak(name) hidden_def (name) | |
37ba7d66 | 644 | # define hidden_ver(local, name) strong_alias (local, __GI_##name) |
c843e065 RM |
645 | # define hidden_data_def(name) strong_data_alias (name, __GI_##name) |
646 | # define hidden_data_weak(name) hidden_data_def (name) | |
647 | # define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name) | |
648 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME | |
649 | # define HIDDEN_JUMPTARGET(name) .__GI_##name | |
650 | # else | |
651 | # define HIDDEN_JUMPTARGET(name) __GI_##name | |
652 | # endif | |
37ba7d66 UD |
653 | # endif |
654 | #else | |
4547dee3 | 655 | # ifndef __ASSEMBLER__ |
81cb0d82 | 656 | # define hidden_proto(name, attrs...) |
4547dee3 RM |
657 | # else |
658 | # define HIDDEN_JUMPTARGET(name) JUMPTARGET(name) | |
659 | # endif /* Not __ASSEMBLER__ */ | |
660 | # define hidden_weak(name) | |
37ba7d66 UD |
661 | # define hidden_def(name) |
662 | # define hidden_ver(local, name) | |
c843e065 RM |
663 | # define hidden_data_weak(name) |
664 | # define hidden_data_def(name) | |
665 | # define hidden_data_ver(local, name) | |
37ba7d66 UD |
666 | #endif |
667 | ||
c5598d47 | 668 | #if !defined NOT_IN_libc |
81cb0d82 | 669 | # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) |
37ba7d66 UD |
670 | # define libc_hidden_def(name) hidden_def (name) |
671 | # define libc_hidden_weak(name) hidden_weak (name) | |
672 | # define libc_hidden_ver(local, name) hidden_ver (local, name) | |
c843e065 RM |
673 | # define libc_hidden_data_def(name) hidden_data_def (name) |
674 | # define libc_hidden_data_weak(name) hidden_data_weak (name) | |
675 | # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name) | |
37ba7d66 | 676 | #else |
81cb0d82 | 677 | # define libc_hidden_proto(name, attrs...) |
37ba7d66 UD |
678 | # define libc_hidden_def(name) |
679 | # define libc_hidden_weak(name) | |
680 | # define libc_hidden_ver(local, name) | |
c843e065 RM |
681 | # define libc_hidden_data_def(name) |
682 | # define libc_hidden_data_weak(name) | |
683 | # define libc_hidden_data_ver(local, name) | |
37ba7d66 UD |
684 | #endif |
685 | ||
c5598d47 | 686 | #if defined NOT_IN_libc && defined IS_IN_rtld |
81cb0d82 | 687 | # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) |
37ba7d66 UD |
688 | # define rtld_hidden_def(name) hidden_def (name) |
689 | # define rtld_hidden_weak(name) hidden_weak (name) | |
690 | # define rtld_hidden_ver(local, name) hidden_ver (local, name) | |
c843e065 RM |
691 | # define rtld_hidden_data_def(name) hidden_data_def (name) |
692 | # define rtld_hidden_data_weak(name) hidden_data_weak (name) | |
693 | # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name) | |
37ba7d66 | 694 | #else |
81cb0d82 | 695 | # define rtld_hidden_proto(name, attrs...) |
37ba7d66 UD |
696 | # define rtld_hidden_def(name) |
697 | # define rtld_hidden_weak(name) | |
698 | # define rtld_hidden_ver(local, name) | |
c843e065 RM |
699 | # define rtld_hidden_data_def(name) |
700 | # define rtld_hidden_data_weak(name) | |
701 | # define rtld_hidden_data_ver(local, name) | |
37ba7d66 UD |
702 | #endif |
703 | ||
c5598d47 | 704 | #if defined NOT_IN_libc && defined IS_IN_libm |
81cb0d82 | 705 | # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) |
37ba7d66 UD |
706 | # define libm_hidden_def(name) hidden_def (name) |
707 | # define libm_hidden_weak(name) hidden_weak (name) | |
708 | # define libm_hidden_ver(local, name) hidden_ver (local, name) | |
c843e065 RM |
709 | # define libm_hidden_data_def(name) hidden_data_def (name) |
710 | # define libm_hidden_data_weak(name) hidden_data_weak (name) | |
711 | # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name) | |
37ba7d66 | 712 | #else |
81cb0d82 | 713 | # define libm_hidden_proto(name, attrs...) |
37ba7d66 UD |
714 | # define libm_hidden_def(name) |
715 | # define libm_hidden_weak(name) | |
716 | # define libm_hidden_ver(local, name) | |
c843e065 RM |
717 | # define libm_hidden_data_def(name) |
718 | # define libm_hidden_data_weak(name) | |
719 | # define libm_hidden_data_ver(local, name) | |
37ba7d66 UD |
720 | #endif |
721 | ||
28f540f4 | 722 | #endif /* libc-symbols.h */ |