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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. | |
40e94df3 | 3 | Copyright (C) 1995-1998,2000,2001,2002,2003 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). */ | |
40e94df3 UD |
119 | # define weak_extern(symbol) _weak_extern (weak symbol) |
120 | # define _weak_extern(expr) _Pragma (#expr) | |
428383e8 UD |
121 | |
122 | # else | |
123 | ||
124 | # define weak_alias(name, aliasname) strong_alias(name, aliasname) | |
125 | # define weak_extern(symbol) /* Nothing. */ | |
126 | ||
127 | # endif | |
128 | ||
129 | #else /* __ASSEMBLER__ */ | |
130 | ||
131 | # ifdef HAVE_ASM_SET_DIRECTIVE | |
c843e065 RM |
132 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
133 | # define strong_alias(original, alias) \ | |
134 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
135 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
136 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
137 | .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original) | |
138 | # define strong_data_alias(original, alias) \ | |
139 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
28f540f4 | 140 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) |
c843e065 RM |
141 | # else |
142 | # define strong_alias(original, alias) \ | |
143 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
144 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) | |
145 | # define strong_data_alias(original, alias) strong_alias(original, alias) | |
146 | # endif | |
dfd2257a | 147 | # else |
2aa15430 | 148 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 RM |
149 | # define strong_alias(original, alias) \ |
150 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
151 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
152 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
2aa15430 | 153 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) |
c843e065 RM |
154 | # define strong_data_alias(original, alias) \ |
155 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
156 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) | |
2aa15430 | 157 | # else |
c843e065 RM |
158 | # define strong_alias(original, alias) \ |
159 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
335aa320 | 160 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
c843e065 | 161 | # define strong_data_alias(original, alias) strong_alias(original, alias) |
2aa15430 | 162 | # endif |
dfd2257a | 163 | # endif |
d02907df | 164 | |
428383e8 | 165 | # ifdef HAVE_WEAK_SYMBOLS |
dfd2257a | 166 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE |
c843e065 RM |
167 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
168 | # define weak_alias(original, alias) \ | |
169 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
170 | .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) | |
171 | # else | |
172 | # define weak_alias(original, alias) \ | |
c224a18a | 173 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) |
c843e065 RM |
174 | # endif |
175 | # define weak_extern(symbol) \ | |
af5b3bc3 | 176 | .weakext C_SYMBOL_NAME (symbol) |
c224a18a | 177 | |
dfd2257a | 178 | # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ |
c224a18a | 179 | |
2aa15430 | 180 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 RM |
181 | # define weak_alias(original, alias) \ |
182 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
183 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
184 | .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
2aa15430 UD |
185 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) |
186 | # else | |
c843e065 RM |
187 | # define weak_alias(original, alias) \ |
188 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
28f540f4 | 189 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
2aa15430 | 190 | # endif |
e6964dd4 | 191 | |
c843e065 | 192 | # define weak_extern(symbol) \ |
af5b3bc3 | 193 | .weak C_SYMBOL_NAME (symbol) |
d02907df | 194 | |
dfd2257a | 195 | # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ |
c224a18a | 196 | |
428383e8 | 197 | # else /* ! HAVE_WEAK_SYMBOLS */ |
af5b3bc3 | 198 | |
428383e8 UD |
199 | # define weak_alias(original, alias) strong_alias(original, alias) |
200 | # define weak_extern(symbol) /* Nothing */ | |
201 | # endif /* ! HAVE_WEAK_SYMBOLS */ | |
af5b3bc3 | 202 | |
428383e8 | 203 | #endif /* __ASSEMBLER__ */ |
958f803f | 204 | |
dfd2257a UD |
205 | /* On some platforms we can make internal function calls (i.e., calls of |
206 | functions not exported) a bit faster by using a different calling | |
207 | convention. */ | |
208 | #ifndef internal_function | |
209 | # define internal_function /* empty */ | |
210 | #endif | |
28f540f4 | 211 | |
a8eab8b1 UD |
212 | /* Prepare for the case that `__builtin_expect' is not available. */ |
213 | #ifndef HAVE_BUILTIN_EXPECT | |
214 | # define __builtin_expect(expr, val) (expr) | |
215 | #endif | |
216 | ||
e862aada UD |
217 | /* Determine the return address. */ |
218 | #define RETURN_ADDRESS(nr) \ | |
219 | __builtin_extract_return_addr (__builtin_return_address (nr)) | |
220 | ||
44c8d1a2 RM |
221 | /* When a reference to SYMBOL is encountered, the linker will emit a |
222 | warning message MSG. */ | |
28f540f4 | 223 | #ifdef HAVE_GNU_LD |
dfd2257a | 224 | # ifdef HAVE_ELF |
fd26970f UD |
225 | |
226 | /* We want the .gnu.warning.SYMBOL section to be unallocated. */ | |
dfd2257a UD |
227 | # ifdef HAVE_ASM_PREVIOUS_DIRECTIVE |
228 | # define __make_section_unallocated(section_string) \ | |
b15cb495 | 229 | asm (".section " section_string "\n\t.previous"); |
e26dd47f | 230 | # elif defined HAVE_ASM_POPSECTION_DIRECTIVE |
dfd2257a | 231 | # define __make_section_unallocated(section_string) \ |
b15cb495 | 232 | asm (".pushsection " section_string "\n\t.popsection"); |
dfd2257a UD |
233 | # else |
234 | # define __make_section_unallocated(section_string) | |
235 | # endif | |
fd26970f | 236 | |
b15cb495 UD |
237 | /* Tacking on "\n\t#" to the section name makes gcc put it's bogus |
238 | section attributes on what looks like a comment to the assembler. */ | |
e26dd47f | 239 | # ifdef HAVE_SECTION_QUOTES |
c877418f | 240 | # define __sec_comment "\"\n\t#\"" |
e26dd47f | 241 | # else |
c877418f RM |
242 | # define __sec_comment "\n\t#" |
243 | # endif | |
244 | # define link_warning(symbol, msg) \ | |
e26dd47f | 245 | __make_section_unallocated (".gnu.warning." #symbol) \ |
44c8d1a2 | 246 | static const char __evoke_link_warning_##symbol[] \ |
c877418f RM |
247 | __attribute__ ((unused, section (".gnu.warning." #symbol __sec_comment))) \ |
248 | = msg; | |
249 | # define libc_freeres_ptr(decl) \ | |
362f5ae2 | 250 | __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \ |
c877418f RM |
251 | decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment))) |
252 | # define __libc_freeres_fn_section \ | |
253 | __attribute__ ((section ("__libc_freeres_fn"))) | |
5af3245a UD |
254 | # else /* Not ELF: a.out */ |
255 | # ifdef HAVE_XCOFF | |
256 | /* XCOFF does not support .stabs. | |
257 | The native aix linker will remove the .stab and .stabstr sections | |
258 | The gnu linker will have a fatal error if there is a relocation for | |
259 | symbol in the .stab section. Silently disable this macro. */ | |
7969407a | 260 | # define link_warning(symbol, msg) |
5af3245a UD |
261 | # else |
262 | # define link_warning(symbol, msg) \ | |
263 | asm (".stabs \"" msg "\",30,0,0,0\n\t" \ | |
264 | ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n"); | |
265 | # endif /* XCOFF */ | |
c877418f RM |
266 | # define libc_freeres_ptr(decl) decl |
267 | # define __libc_freeres_fn_section | |
dfd2257a | 268 | # endif |
28f540f4 RM |
269 | #else |
270 | /* We will never be heard; they will all die horribly. */ | |
dfd2257a | 271 | # define link_warning(symbol, msg) |
c877418f RM |
272 | # define libc_freeres_ptr(decl) decl |
273 | # define __libc_freeres_fn_section | |
28f540f4 | 274 | #endif |
c877418f RM |
275 | #define libc_freeres_fn(name) \ |
276 | static void name (void) __attribute_used__ __libc_freeres_fn_section; \ | |
277 | text_set_element (__libc_subfreeres, name); \ | |
278 | static void name (void) | |
28f540f4 RM |
279 | |
280 | /* A canned warning for sysdeps/stub functions. */ | |
281 | #define stub_warning(name) \ | |
44c8d1a2 RM |
282 | link_warning (name, \ |
283 | "warning: " #name " is not implemented and will always fail") | |
5f9e57ba | 284 | |
b88ac073 RM |
285 | |
286 | /* Declare SYMBOL to be TYPE (`function' or `object') and of SIZE bytes, | |
287 | when the assembler supports such declarations (such as in ELF). | |
288 | This is only necessary when defining something in assembly, or playing | |
289 | funny alias games where the size should be other than what the compiler | |
290 | thinks it is. */ | |
291 | #define declare_symbol(symbol, type, size) \ | |
292 | declare_symbol_1 (symbol, type, size) | |
293 | #ifdef ASM_TYPE_DIRECTIVE_PREFIX | |
294 | # ifdef __ASSEMBLER__ | |
295 | # define declare_symbol_1(symbol, type, size) \ | |
296 | .type C_SYMBOL_NAME (symbol), \ | |
297 | declare_symbol_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type), size | |
298 | # define declare_symbol_1_paste(a, b) declare_symbol_1_paste_1 (a,b) | |
299 | # define declare_symbol_1_paste_1(a,b) a##b | |
300 | # else /* Not __ASSEMBLER__. */ | |
301 | # define declare_symbol_1(symbol, type, size) \ | |
9e7f59b4 | 302 | asm (".type " __SYMBOL_PREFIX #symbol ", " \ |
b88ac073 RM |
303 | declare_symbol_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \ |
304 | "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size); | |
305 | # define declare_symbol_1_stringify(x) declare_symbol_1_stringify_1 (x) | |
306 | # define declare_symbol_1_stringify_1(x) #x | |
307 | # endif /* __ASSEMBLER__ */ | |
308 | #else | |
309 | # define declare_symbol_1(symbol, type, size) /* Nothing. */ | |
310 | #endif | |
311 | ||
312 | ||
5f9e57ba | 313 | /* |
28f540f4 | 314 | \f |
5f9e57ba RM |
315 | */ |
316 | ||
28f540f4 RM |
317 | #ifdef HAVE_GNU_LD |
318 | ||
319 | /* Symbol set support macros. */ | |
320 | ||
dfd2257a | 321 | # ifdef HAVE_ELF |
28f540f4 RM |
322 | |
323 | /* Make SYMBOL, which is in the text segment, an element of SET. */ | |
dfd2257a | 324 | # define text_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 | 325 | /* Make SYMBOL, which is in the data segment, an element of SET. */ |
dfd2257a | 326 | # define data_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 | 327 | /* Make SYMBOL, which is in the bss segment, an element of SET. */ |
dfd2257a | 328 | # define bss_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 RM |
329 | |
330 | /* These are all done the same way in ELF. | |
331 | There is a new section created for each set. */ | |
b5567b2a | 332 | # ifdef SHARED |
53afa8d9 RM |
333 | /* When building a shared library, make the set section writable, |
334 | because it will need to be relocated at run time anyway. */ | |
dfd2257a | 335 | # define _elf_set_element(set, symbol) \ |
53afa8d9 | 336 | static const void *__elf_set_##set##_element_##symbol##__ \ |
d6e2f671 | 337 | __attribute__ ((unused, section (#set))) = &(symbol) |
dfd2257a UD |
338 | # else |
339 | # define _elf_set_element(set, symbol) \ | |
28f540f4 | 340 | static const void *const __elf_set_##set##_element_##symbol##__ \ |
d6e2f671 | 341 | __attribute__ ((unused, section (#set))) = &(symbol) |
dfd2257a | 342 | # endif |
28f540f4 RM |
343 | |
344 | /* Define SET as a symbol set. This may be required (it is in a.out) to | |
345 | be able to use the set's contents. */ | |
dfd2257a | 346 | # define symbol_set_define(set) symbol_set_declare(set) |
28f540f4 | 347 | |
20792f99 RM |
348 | /* Declare SET for use in this module, if defined in another module. |
349 | In a shared library, this is always local to that shared object. | |
350 | For static linking, the set might be wholly absent and so we use | |
351 | weak references. */ | |
dfd2257a | 352 | # define symbol_set_declare(set) \ |
20792f99 RM |
353 | extern void *const __start_##set __symbol_set_attribute; \ |
354 | extern void *const __stop_##set __symbol_set_attribute; | |
355 | # ifdef SHARED | |
356 | # define __symbol_set_attribute attribute_hidden | |
357 | # else | |
358 | # define __symbol_set_attribute __attribute__ ((weak)) | |
359 | # endif | |
28f540f4 RM |
360 | |
361 | /* Return a pointer (void *const *) to the first element of SET. */ | |
dfd2257a | 362 | # define symbol_set_first_element(set) (&__start_##set) |
28f540f4 RM |
363 | |
364 | /* Return true iff PTR (a void *const *) has been incremented | |
365 | past the last element in SET. */ | |
dfd2257a | 366 | # define symbol_set_end_p(set, ptr) ((ptr) >= &__stop_##set) |
28f540f4 | 367 | |
dfd2257a | 368 | # else /* Not ELF: a.out. */ |
28f540f4 | 369 | |
5af3245a UD |
370 | # ifdef HAVE_XCOFF |
371 | /* XCOFF does not support .stabs. | |
372 | The native aix linker will remove the .stab and .stabstr sections | |
373 | The gnu linker will have a fatal error if there is a relocation for | |
374 | symbol in the .stab section. Silently disable these macros. */ | |
7969407a UD |
375 | # define text_set_element(set, symbol) |
376 | # define data_set_element(set, symbol) | |
377 | # define bss_set_element(set, symbol) | |
5af3245a UD |
378 | # else |
379 | # define text_set_element(set, symbol) \ | |
380 | asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol) | |
381 | # define data_set_element(set, symbol) \ | |
382 | asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol) | |
383 | # define bss_set_element(set, symbol) ?error Must use initialized data. | |
384 | # endif /* XCOFF */ | |
dfd2257a | 385 | # define symbol_set_define(set) void *const (set)[1]; |
03df72bf | 386 | # define symbol_set_declare(set) extern void *const (set)[1]; |
28f540f4 | 387 | |
dfd2257a UD |
388 | # define symbol_set_first_element(set) &(set)[1] |
389 | # define symbol_set_end_p(set, ptr) (*(ptr) == 0) | |
28f540f4 | 390 | |
dfd2257a | 391 | # endif /* ELF. */ |
a2a89dd6 UD |
392 | #else |
393 | /* We cannot do anything in generial. */ | |
394 | # define text_set_element(set, symbol) asm ("") | |
395 | # define data_set_element(set, symbol) asm ("") | |
396 | # define bss_set_element(set, symbol) asm ("") | |
397 | # define symbol_set_define(set) void *const (set)[1]; | |
398 | # define symbol_set_declare(set) extern void *const (set)[1]; | |
399 | ||
400 | # define symbol_set_first_element(set) &(set)[1] | |
401 | # define symbol_set_end_p(set, ptr) (*(ptr) == 0) | |
28f540f4 RM |
402 | #endif /* Have GNU ld. */ |
403 | ||
1ea89a40 | 404 | #if DO_VERSIONING |
ebdf53a7 | 405 | # define symbol_version(real, name, version) \ |
8b943b4a | 406 | _symbol_version(real, name, version) |
ebdf53a7 GM |
407 | # define default_symbol_version(real, name, version) \ |
408 | _default_symbol_version(real, name, version) | |
409 | # ifdef __ASSEMBLER__ | |
c843e065 RM |
410 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
411 | # define _symbol_version(real, name, version) \ | |
412 | .symver real, name##@##version ASM_LINE_SEP \ | |
413 | .symver .##real, .##name##@##version | |
414 | # define _default_symbol_version(real, name, version) \ | |
415 | .symver real, name##@##@##version ASM_LINE_SEP \ | |
416 | .symver .##real, .##name##@##@##version | |
417 | # else | |
418 | # define _symbol_version(real, name, version) \ | |
da2d1bc5 | 419 | .symver real, name##@##version |
c843e065 | 420 | # define _default_symbol_version(real, name, version) \ |
da2d1bc5 | 421 | .symver real, name##@##@##version |
c843e065 | 422 | # endif |
da2d1bc5 | 423 | # else |
c843e065 RM |
424 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
425 | # define _symbol_version(real, name, version) \ | |
426 | __asm__ (".symver " #real "," #name "@" #version "\n\t" \ | |
427 | ".symver ." #real ",." #name "@" #version) | |
428 | # define _default_symbol_version(real, name, version) \ | |
429 | __asm__ (".symver " #real "," #name "@@" #version "\n\t" \ | |
430 | ".symver ." #real ",." #name "@@" #version) | |
431 | # else | |
432 | # define _symbol_version(real, name, version) \ | |
1ea89a40 | 433 | __asm__ (".symver " #real "," #name "@" #version) |
c843e065 | 434 | # define _default_symbol_version(real, name, version) \ |
f2ea0f5b | 435 | __asm__ (".symver " #real "," #name "@@" #version) |
c843e065 | 436 | # endif |
da2d1bc5 | 437 | # endif |
1ea89a40 UD |
438 | #else |
439 | # define symbol_version(real, name, version) | |
da2d1bc5 UD |
440 | # define default_symbol_version(real, name, version) \ |
441 | strong_alias(real, name) | |
1ea89a40 UD |
442 | #endif |
443 | ||
e6caf4e1 UD |
444 | #if defined HAVE_VISIBILITY_ATTRIBUTE && defined SHARED |
445 | # define attribute_hidden __attribute__ ((visibility ("hidden"))) | |
446 | #else | |
447 | # define attribute_hidden | |
448 | #endif | |
449 | ||
9b21e6bc RM |
450 | #if defined HAVE_TLS_MODEL_ATTRIBUTE |
451 | # define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec"))) | |
452 | #else | |
453 | # define attribute_tls_model_ie | |
454 | #endif | |
455 | ||
7969407a UD |
456 | /* Handling on non-exported internal names. We have to do this only |
457 | for shared code. */ | |
458 | #ifdef SHARED | |
cff26a3e | 459 | # define INTUSE(name) name##_internal |
e6caf4e1 UD |
460 | # define INTDEF(name) strong_alias (name, name##_internal) |
461 | # define INTVARDEF(name) \ | |
1897bc3f | 462 | _INTVARDEF (name, name##_internal) |
7f0244de AJ |
463 | # if defined HAVE_VISIBILITY_ATTRIBUTE |
464 | # define _INTVARDEF(name, aliasname) \ | |
100351c3 UD |
465 | extern __typeof (name) aliasname __attribute__ ((alias (#name), \ |
466 | visibility ("hidden"))); | |
7f0244de AJ |
467 | # else |
468 | # define _INTVARDEF(name, aliasname) \ | |
469 | extern __typeof (name) aliasname __attribute__ ((alias (#name))); | |
470 | # endif | |
e6caf4e1 | 471 | # define INTDEF2(name, newname) strong_alias (name, newname##_internal) |
1897bc3f | 472 | # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal) |
7969407a | 473 | #else |
cff26a3e | 474 | # define INTUSE(name) name |
7969407a | 475 | # define INTDEF(name) |
e6caf4e1 | 476 | # define INTVARDEF(name) |
77fe0b9c | 477 | # define INTDEF2(name, newname) |
1897bc3f | 478 | # define INTVARDEF2(name, newname) |
7969407a UD |
479 | #endif |
480 | ||
37ba7d66 UD |
481 | /* The following macros are used for PLT bypassing within libc.so |
482 | (and if needed other libraries similarly). | |
483 | First of all, you need to have the function prototyped somewhere, | |
484 | say in foo/foo.h: | |
485 | ||
486 | int foo (int __bar); | |
487 | ||
488 | If calls to foo within libc.so should always go to foo defined in libc.so, | |
489 | then in include/foo.h you add: | |
490 | ||
491 | libc_hidden_proto (foo) | |
492 | ||
493 | line and after the foo function definition: | |
494 | ||
495 | int foo (int __bar) | |
496 | { | |
497 | return __bar; | |
498 | } | |
499 | libc_hidden_def (foo) | |
500 | ||
501 | or | |
502 | ||
503 | int foo (int __bar) | |
504 | { | |
505 | return __bar; | |
506 | } | |
507 | libc_hidden_weak (foo) | |
508 | ||
c843e065 RM |
509 | Simularly for global data. If references to foo within libc.so should |
510 | always go to foo defined in libc.so, then in include/foo.h you add: | |
511 | ||
512 | libc_hidden_proto (foo) | |
513 | ||
514 | line and after foo's definition: | |
515 | ||
516 | int foo = INITIAL_FOO_VALUE; | |
517 | libc_hidden_data_def (foo) | |
518 | ||
519 | or | |
520 | ||
521 | int foo = INITIAL_FOO_VALUE; | |
522 | libc_hidden_data_weak (foo) | |
523 | ||
37ba7d66 UD |
524 | If foo is normally just an alias (strong or weak) of some other function, |
525 | you should use the normal strong_alias first, then add libc_hidden_def | |
526 | or libc_hidden_weak: | |
527 | ||
528 | int baz (int __bar) | |
529 | { | |
530 | return __bar; | |
531 | } | |
532 | strong_alias (baz, foo) | |
533 | libc_hidden_weak (foo) | |
534 | ||
535 | If the function should be internal to multiple objects, say ld.so and | |
536 | libc.so, the best way is to use: | |
537 | ||
538 | #if !defined NOT_IN_libc || defined IS_IN_rtld | |
539 | hidden_proto (foo) | |
540 | #endif | |
541 | ||
542 | in include/foo.h and the normal macros at all function definitions | |
543 | depending on what DSO they belong to. | |
544 | ||
545 | If versioned_symbol macro is used to define foo, | |
546 | libc_hidden_ver macro should be used, as in: | |
547 | ||
548 | int __real_foo (int __bar) | |
549 | { | |
550 | return __bar; | |
551 | } | |
552 | versioned_symbol (libc, __real_foo, foo, GLIBC_2_1); | |
553 | libc_hidden_ver (__real_foo, foo) */ | |
554 | ||
2b29b5ac | 555 | #if defined SHARED && defined DO_VERSIONING \ |
749a9a4f | 556 | && !defined HAVE_BROKEN_ALIAS_ATTRIBUTE && !defined NO_HIDDEN |
37ba7d66 | 557 | # ifndef __ASSEMBLER__ |
81cb0d82 UD |
558 | # if !defined HAVE_VISIBILITY_ATTRIBUTE \ |
559 | || defined HAVE_BROKEN_VISIBILITY_ATTRIBUTE | |
560 | # define __hidden_proto_hiddenattr(attrs...) | |
37ba7d66 | 561 | # else |
81cb0d82 UD |
562 | # define __hidden_proto_hiddenattr(attrs...) \ |
563 | __attribute__ ((visibility ("hidden"), ##attrs)) | |
37ba7d66 | 564 | # endif |
81cb0d82 UD |
565 | # define hidden_proto(name, attrs...) \ |
566 | __hidden_proto (name, __GI_##name, ##attrs) | |
567 | # define __hidden_proto(name, internal, attrs...) \ | |
a585ba22 RM |
568 | extern __typeof (name) internal; \ |
569 | extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \ | |
81cb0d82 | 570 | __hidden_proto_hiddenattr (attrs); |
37ba7d66 UD |
571 | # define __hidden_asmname(name) \ |
572 | __hidden_asmname1 (__USER_LABEL_PREFIX__, name) | |
573 | # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name) | |
574 | # define __hidden_asmname2(prefix, name) #prefix name | |
575 | # ifdef HAVE_ASM_SET_DIRECTIVE | |
576 | # define __hidden_def1(original, alias) \ | |
577 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
578 | .set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) | |
37ba7d66 | 579 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 | 580 | # define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ |
37ba7d66 | 581 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ |
c843e065 | 582 | .set C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) |
37ba7d66 | 583 | # else |
c843e065 RM |
584 | # define __hidden_dot_def1(original, alias) |
585 | # endif | |
586 | # else | |
587 | # define __hidden_def1(original, alias) \ | |
37ba7d66 UD |
588 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
589 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) | |
c843e065 RM |
590 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
591 | # define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ | |
592 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
593 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) | |
594 | # else | |
d7abce98 | 595 | # define __hidden_dot_def1(original, alias) |
37ba7d66 UD |
596 | # endif |
597 | # endif | |
598 | # define __hidden_def2(...) #__VA_ARGS__ | |
599 | # define __hidden_def3(...) __hidden_def2 (__VA_ARGS__) | |
600 | # define hidden_def(name) \ | |
c843e065 RM |
601 | __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name) \ |
602 | __hidden_dot_def1 (__GI_##name, name))); | |
603 | # define hidden_data_def(name) \ | |
37ba7d66 UD |
604 | __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name))); |
605 | # define hidden_ver(local, name) \ | |
c843e065 RM |
606 | __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name) \ |
607 | __hidden_dot_def1 (local, __GI_##name))); | |
608 | # define hidden_data_ver(local, name) \ | |
37ba7d66 UD |
609 | __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name))); |
610 | # ifdef HAVE_WEAK_SYMBOLS | |
611 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE | |
612 | # define __hidden_weak1(original, alias) \ | |
613 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) | |
37ba7d66 | 614 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
c843e065 RM |
615 | # define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ |
616 | .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) | |
617 | # else | |
618 | # define __hidden_dot_weak1(original, alias) | |
619 | # endif | |
620 | # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ | |
621 | # define __hidden_weak1(original, alias) \ | |
37ba7d66 | 622 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
c843e065 RM |
623 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
624 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME | |
625 | # define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ | |
c7f09319 | 626 | .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ |
37ba7d66 UD |
627 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) |
628 | # else | |
c843e065 | 629 | # define __hidden_dot_weak1(original, alias) |
37ba7d66 UD |
630 | # endif |
631 | # endif | |
632 | # define hidden_weak(name) \ | |
c843e065 RM |
633 | __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name) \ |
634 | __hidden_dot_weak1 (__GI_##name, name))); | |
635 | # define hidden_data_weak(name) \ | |
37ba7d66 UD |
636 | __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name))); |
637 | # else | |
638 | # define hidden_weak(name) hidden_def (name) | |
639 | # endif | |
640 | # else | |
641 | /* For assembly, we need to do the opposite of what we do in C: | |
642 | in assembly gcc __REDIRECT stuff is not in place, so functions | |
643 | are defined by its normal name and we need to create the | |
644 | __GI_* alias to it, in C __REDIRECT causes the function definition | |
645 | to use __GI_* name and we need to add alias to the real name. | |
4547dee3 RM |
646 | There is no reason to use hidden_weak over hidden_def in assembly, |
647 | but we provide it for consistency with the C usage. | |
648 | hidden_proto doesn't make sense for assembly but the equivalent | |
dce8f2b6 | 649 | is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET. */ |
4547dee3 RM |
650 | # define hidden_def(name) strong_alias (name, __GI_##name) |
651 | # define hidden_weak(name) hidden_def (name) | |
37ba7d66 | 652 | # define hidden_ver(local, name) strong_alias (local, __GI_##name) |
c843e065 RM |
653 | # define hidden_data_def(name) strong_data_alias (name, __GI_##name) |
654 | # define hidden_data_weak(name) hidden_data_def (name) | |
655 | # define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name) | |
656 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME | |
657 | # define HIDDEN_JUMPTARGET(name) .__GI_##name | |
658 | # else | |
659 | # define HIDDEN_JUMPTARGET(name) __GI_##name | |
660 | # endif | |
37ba7d66 UD |
661 | # endif |
662 | #else | |
4547dee3 | 663 | # ifndef __ASSEMBLER__ |
81cb0d82 | 664 | # define hidden_proto(name, attrs...) |
4547dee3 RM |
665 | # else |
666 | # define HIDDEN_JUMPTARGET(name) JUMPTARGET(name) | |
667 | # endif /* Not __ASSEMBLER__ */ | |
668 | # define hidden_weak(name) | |
37ba7d66 UD |
669 | # define hidden_def(name) |
670 | # define hidden_ver(local, name) | |
c843e065 RM |
671 | # define hidden_data_weak(name) |
672 | # define hidden_data_def(name) | |
673 | # define hidden_data_ver(local, name) | |
37ba7d66 UD |
674 | #endif |
675 | ||
c5598d47 | 676 | #if !defined NOT_IN_libc |
81cb0d82 | 677 | # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) |
37ba7d66 UD |
678 | # define libc_hidden_def(name) hidden_def (name) |
679 | # define libc_hidden_weak(name) hidden_weak (name) | |
680 | # define libc_hidden_ver(local, name) hidden_ver (local, name) | |
c843e065 RM |
681 | # define libc_hidden_data_def(name) hidden_data_def (name) |
682 | # define libc_hidden_data_weak(name) hidden_data_weak (name) | |
683 | # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name) | |
37ba7d66 | 684 | #else |
81cb0d82 | 685 | # define libc_hidden_proto(name, attrs...) |
37ba7d66 UD |
686 | # define libc_hidden_def(name) |
687 | # define libc_hidden_weak(name) | |
688 | # define libc_hidden_ver(local, name) | |
c843e065 RM |
689 | # define libc_hidden_data_def(name) |
690 | # define libc_hidden_data_weak(name) | |
691 | # define libc_hidden_data_ver(local, name) | |
37ba7d66 UD |
692 | #endif |
693 | ||
c5598d47 | 694 | #if defined NOT_IN_libc && defined IS_IN_rtld |
81cb0d82 | 695 | # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) |
37ba7d66 UD |
696 | # define rtld_hidden_def(name) hidden_def (name) |
697 | # define rtld_hidden_weak(name) hidden_weak (name) | |
698 | # define rtld_hidden_ver(local, name) hidden_ver (local, name) | |
c843e065 RM |
699 | # define rtld_hidden_data_def(name) hidden_data_def (name) |
700 | # define rtld_hidden_data_weak(name) hidden_data_weak (name) | |
701 | # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name) | |
37ba7d66 | 702 | #else |
81cb0d82 | 703 | # define rtld_hidden_proto(name, attrs...) |
37ba7d66 UD |
704 | # define rtld_hidden_def(name) |
705 | # define rtld_hidden_weak(name) | |
706 | # define rtld_hidden_ver(local, name) | |
c843e065 RM |
707 | # define rtld_hidden_data_def(name) |
708 | # define rtld_hidden_data_weak(name) | |
709 | # define rtld_hidden_data_ver(local, name) | |
37ba7d66 UD |
710 | #endif |
711 | ||
c5598d47 | 712 | #if defined NOT_IN_libc && defined IS_IN_libm |
81cb0d82 | 713 | # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) |
37ba7d66 UD |
714 | # define libm_hidden_def(name) hidden_def (name) |
715 | # define libm_hidden_weak(name) hidden_weak (name) | |
716 | # define libm_hidden_ver(local, name) hidden_ver (local, name) | |
c843e065 RM |
717 | # define libm_hidden_data_def(name) hidden_data_def (name) |
718 | # define libm_hidden_data_weak(name) hidden_data_weak (name) | |
719 | # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name) | |
37ba7d66 | 720 | #else |
81cb0d82 | 721 | # define libm_hidden_proto(name, attrs...) |
37ba7d66 UD |
722 | # define libm_hidden_def(name) |
723 | # define libm_hidden_weak(name) | |
724 | # define libm_hidden_ver(local, name) | |
c843e065 RM |
725 | # define libm_hidden_data_def(name) |
726 | # define libm_hidden_data_weak(name) | |
727 | # define libm_hidden_data_ver(local, name) | |
37ba7d66 UD |
728 | #endif |
729 | ||
85dd1003 UD |
730 | #ifdef HAVE_BUILTIN_REDIRECTION |
731 | # define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs) | |
732 | # define libc_hidden_builtin_def(name) libc_hidden_def (name) | |
733 | # define libc_hidden_builtin_weak(name) libc_hidden_weak (name) | |
734 | # define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name) | |
735 | #else | |
736 | # define libc_hidden_builtin_proto(name, attrs...) | |
737 | # define libc_hidden_builtin_def(name) | |
738 | # define libc_hidden_builtin_weak(name) | |
739 | # define libc_hidden_builtin_ver(local, name) | |
740 | #endif | |
741 | ||
28f540f4 | 742 | #endif /* libc-symbols.h */ |