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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 | ||
256ba888 UD |
85 | #ifndef C_SYMBOL_DOT_NAME |
86 | # define C_SYMBOL_DOT_NAME(name) .##name | |
87 | #endif | |
88 | ||
428383e8 UD |
89 | #ifndef __ASSEMBLER__ |
90 | /* GCC understands weak symbols and aliases; use its interface where | |
91 | possible, instead of embedded assembly language. */ | |
d02907df | 92 | |
428383e8 | 93 | /* Define ALIASNAME as a strong alias for NAME. */ |
c62f5cab GM |
94 | # define strong_alias(name, aliasname) _strong_alias(name, aliasname) |
95 | # define _strong_alias(name, aliasname) \ | |
428383e8 UD |
96 | extern __typeof (name) aliasname __attribute__ ((alias (#name))); |
97 | ||
98 | /* This comes between the return type and function name in | |
99 | a function definition to make that definition weak. */ | |
100 | # define weak_function __attribute__ ((weak)) | |
101 | # define weak_const_function __attribute__ ((weak, __const__)) | |
102 | ||
103 | # ifdef HAVE_WEAK_SYMBOLS | |
104 | ||
105 | /* Define ALIASNAME as a weak alias for NAME. | |
106 | If weak aliases are not available, this defines a strong alias. */ | |
c62f5cab GM |
107 | # define weak_alias(name, aliasname) _weak_alias (name, aliasname) |
108 | # define _weak_alias(name, aliasname) \ | |
428383e8 UD |
109 | extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))); |
110 | ||
111 | /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ | |
ebdf53a7 | 112 | # define weak_extern(symbol) _weak_extern (symbol) |
428383e8 | 113 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE |
ebdf53a7 | 114 | # define _weak_extern(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol); |
428383e8 | 115 | # else |
ebdf53a7 | 116 | # define _weak_extern(symbol) asm (".weak " __SYMBOL_PREFIX #symbol); |
428383e8 UD |
117 | # endif |
118 | ||
119 | # else | |
120 | ||
121 | # define weak_alias(name, aliasname) strong_alias(name, aliasname) | |
122 | # define weak_extern(symbol) /* Nothing. */ | |
123 | ||
124 | # endif | |
125 | ||
126 | #else /* __ASSEMBLER__ */ | |
127 | ||
128 | # ifdef HAVE_ASM_SET_DIRECTIVE | |
129 | # define strong_alias(original, alias) \ | |
b15cb495 | 130 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
28f540f4 | 131 | .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) |
dfd2257a | 132 | # else |
2aa15430 UD |
133 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
134 | # define strong_alias(original, alias) \ | |
135 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
136 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
137 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
138 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) | |
139 | # else | |
140 | # define strong_alias(original, alias) \ | |
b15cb495 | 141 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
335aa320 | 142 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
2aa15430 | 143 | # endif |
dfd2257a | 144 | # endif |
d02907df | 145 | |
428383e8 | 146 | # ifdef HAVE_WEAK_SYMBOLS |
dfd2257a | 147 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE |
dfd2257a | 148 | # define weak_alias(original, alias) \ |
c224a18a | 149 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) |
dfd2257a | 150 | # define weak_extern(symbol) \ |
af5b3bc3 | 151 | .weakext C_SYMBOL_NAME (symbol) |
c224a18a | 152 | |
dfd2257a | 153 | # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ |
c224a18a | 154 | |
2aa15430 UD |
155 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME |
156 | # define weak_alias(original, alias) \ | |
157 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
158 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
d436a9f7 | 159 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ |
2aa15430 UD |
160 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) |
161 | # else | |
162 | # define weak_alias(original, alias) \ | |
b15cb495 | 163 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ |
28f540f4 | 164 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) |
2aa15430 | 165 | # endif |
e6964dd4 | 166 | |
dfd2257a | 167 | # define weak_extern(symbol) \ |
af5b3bc3 | 168 | .weak C_SYMBOL_NAME (symbol) |
d02907df | 169 | |
dfd2257a | 170 | # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ |
c224a18a | 171 | |
428383e8 | 172 | # else /* ! HAVE_WEAK_SYMBOLS */ |
af5b3bc3 | 173 | |
428383e8 UD |
174 | # define weak_alias(original, alias) strong_alias(original, alias) |
175 | # define weak_extern(symbol) /* Nothing */ | |
176 | # endif /* ! HAVE_WEAK_SYMBOLS */ | |
af5b3bc3 | 177 | |
428383e8 | 178 | #endif /* __ASSEMBLER__ */ |
958f803f | 179 | |
dfd2257a UD |
180 | /* On some platforms we can make internal function calls (i.e., calls of |
181 | functions not exported) a bit faster by using a different calling | |
182 | convention. */ | |
183 | #ifndef internal_function | |
184 | # define internal_function /* empty */ | |
185 | #endif | |
28f540f4 | 186 | |
a8eab8b1 UD |
187 | /* Prepare for the case that `__builtin_expect' is not available. */ |
188 | #ifndef HAVE_BUILTIN_EXPECT | |
189 | # define __builtin_expect(expr, val) (expr) | |
190 | #endif | |
191 | ||
e862aada UD |
192 | /* Determine the return address. */ |
193 | #define RETURN_ADDRESS(nr) \ | |
194 | __builtin_extract_return_addr (__builtin_return_address (nr)) | |
195 | ||
44c8d1a2 RM |
196 | /* When a reference to SYMBOL is encountered, the linker will emit a |
197 | warning message MSG. */ | |
28f540f4 | 198 | #ifdef HAVE_GNU_LD |
dfd2257a | 199 | # ifdef HAVE_ELF |
fd26970f UD |
200 | |
201 | /* We want the .gnu.warning.SYMBOL section to be unallocated. */ | |
dfd2257a UD |
202 | # ifdef HAVE_ASM_PREVIOUS_DIRECTIVE |
203 | # define __make_section_unallocated(section_string) \ | |
b15cb495 | 204 | asm (".section " section_string "\n\t.previous"); |
e26dd47f | 205 | # elif defined HAVE_ASM_POPSECTION_DIRECTIVE |
dfd2257a | 206 | # define __make_section_unallocated(section_string) \ |
b15cb495 | 207 | asm (".pushsection " section_string "\n\t.popsection"); |
dfd2257a UD |
208 | # else |
209 | # define __make_section_unallocated(section_string) | |
210 | # endif | |
fd26970f | 211 | |
b15cb495 UD |
212 | /* Tacking on "\n\t#" to the section name makes gcc put it's bogus |
213 | section attributes on what looks like a comment to the assembler. */ | |
e26dd47f UD |
214 | # ifdef HAVE_SECTION_QUOTES |
215 | # define link_warning(symbol, msg) \ | |
216 | __make_section_unallocated (".gnu.warning." #symbol) \ | |
217 | static const char __evoke_link_warning_##symbol[] \ | |
13176c60 RM |
218 | __attribute__ ((unused, section (".gnu.warning." #symbol "\"\n\t#\""))) \ |
219 | = msg; | |
e26dd47f UD |
220 | # else |
221 | # define link_warning(symbol, msg) \ | |
222 | __make_section_unallocated (".gnu.warning." #symbol) \ | |
44c8d1a2 | 223 | static const char __evoke_link_warning_##symbol[] \ |
13176c60 | 224 | __attribute__ ((unused, section (".gnu.warning." #symbol "\n\t#"))) = msg; |
e26dd47f | 225 | # endif |
5af3245a UD |
226 | # else /* Not ELF: a.out */ |
227 | # ifdef HAVE_XCOFF | |
228 | /* XCOFF does not support .stabs. | |
229 | The native aix linker will remove the .stab and .stabstr sections | |
230 | The gnu linker will have a fatal error if there is a relocation for | |
231 | symbol in the .stab section. Silently disable this macro. */ | |
7969407a | 232 | # define link_warning(symbol, msg) |
5af3245a UD |
233 | # else |
234 | # define link_warning(symbol, msg) \ | |
235 | asm (".stabs \"" msg "\",30,0,0,0\n\t" \ | |
236 | ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n"); | |
237 | # endif /* XCOFF */ | |
dfd2257a | 238 | # endif |
28f540f4 RM |
239 | #else |
240 | /* We will never be heard; they will all die horribly. */ | |
dfd2257a | 241 | # define link_warning(symbol, msg) |
28f540f4 RM |
242 | #endif |
243 | ||
244 | /* A canned warning for sysdeps/stub functions. */ | |
245 | #define stub_warning(name) \ | |
44c8d1a2 RM |
246 | link_warning (name, \ |
247 | "warning: " #name " is not implemented and will always fail") | |
5f9e57ba | 248 | |
b88ac073 RM |
249 | |
250 | /* Declare SYMBOL to be TYPE (`function' or `object') and of SIZE bytes, | |
251 | when the assembler supports such declarations (such as in ELF). | |
252 | This is only necessary when defining something in assembly, or playing | |
253 | funny alias games where the size should be other than what the compiler | |
254 | thinks it is. */ | |
255 | #define declare_symbol(symbol, type, size) \ | |
256 | declare_symbol_1 (symbol, type, size) | |
257 | #ifdef ASM_TYPE_DIRECTIVE_PREFIX | |
258 | # ifdef __ASSEMBLER__ | |
259 | # define declare_symbol_1(symbol, type, size) \ | |
260 | .type C_SYMBOL_NAME (symbol), \ | |
261 | declare_symbol_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type), size | |
262 | # define declare_symbol_1_paste(a, b) declare_symbol_1_paste_1 (a,b) | |
263 | # define declare_symbol_1_paste_1(a,b) a##b | |
264 | # else /* Not __ASSEMBLER__. */ | |
265 | # define declare_symbol_1(symbol, type, size) \ | |
266 | asm (".type " __SYMBOL_PREFIX #symbol \ | |
267 | declare_symbol_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \ | |
268 | "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size); | |
269 | # define declare_symbol_1_stringify(x) declare_symbol_1_stringify_1 (x) | |
270 | # define declare_symbol_1_stringify_1(x) #x | |
271 | # endif /* __ASSEMBLER__ */ | |
272 | #else | |
273 | # define declare_symbol_1(symbol, type, size) /* Nothing. */ | |
274 | #endif | |
275 | ||
276 | ||
5f9e57ba | 277 | /* |
28f540f4 | 278 | \f |
5f9e57ba RM |
279 | */ |
280 | ||
28f540f4 RM |
281 | #ifdef HAVE_GNU_LD |
282 | ||
283 | /* Symbol set support macros. */ | |
284 | ||
dfd2257a | 285 | # ifdef HAVE_ELF |
28f540f4 RM |
286 | |
287 | /* Make SYMBOL, which is in the text segment, an element of SET. */ | |
dfd2257a | 288 | # define text_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 | 289 | /* Make SYMBOL, which is in the data segment, an element of SET. */ |
dfd2257a | 290 | # define data_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 | 291 | /* Make SYMBOL, which is in the bss segment, an element of SET. */ |
dfd2257a | 292 | # define bss_set_element(set, symbol) _elf_set_element(set, symbol) |
28f540f4 RM |
293 | |
294 | /* These are all done the same way in ELF. | |
295 | There is a new section created for each set. */ | |
b5567b2a | 296 | # ifdef SHARED |
53afa8d9 RM |
297 | /* When building a shared library, make the set section writable, |
298 | because it will need to be relocated at run time anyway. */ | |
dfd2257a | 299 | # define _elf_set_element(set, symbol) \ |
53afa8d9 | 300 | static const void *__elf_set_##set##_element_##symbol##__ \ |
d6e2f671 | 301 | __attribute__ ((unused, section (#set))) = &(symbol) |
dfd2257a UD |
302 | # else |
303 | # define _elf_set_element(set, symbol) \ | |
28f540f4 | 304 | static const void *const __elf_set_##set##_element_##symbol##__ \ |
d6e2f671 | 305 | __attribute__ ((unused, section (#set))) = &(symbol) |
dfd2257a | 306 | # endif |
28f540f4 RM |
307 | |
308 | /* Define SET as a symbol set. This may be required (it is in a.out) to | |
309 | be able to use the set's contents. */ | |
dfd2257a | 310 | # define symbol_set_define(set) symbol_set_declare(set) |
28f540f4 RM |
311 | |
312 | /* Declare SET for use in this module, if defined in another module. */ | |
dfd2257a | 313 | # define symbol_set_declare(set) \ |
03df72bf GM |
314 | extern void *const __start_##set __attribute__ ((__weak__)); \ |
315 | extern void *const __stop_##set __attribute__ ((__weak__)); \ | |
af5b3bc3 | 316 | weak_extern (__start_##set) weak_extern (__stop_##set) |
28f540f4 RM |
317 | |
318 | /* Return a pointer (void *const *) to the first element of SET. */ | |
dfd2257a | 319 | # define symbol_set_first_element(set) (&__start_##set) |
28f540f4 RM |
320 | |
321 | /* Return true iff PTR (a void *const *) has been incremented | |
322 | past the last element in SET. */ | |
dfd2257a | 323 | # define symbol_set_end_p(set, ptr) ((ptr) >= &__stop_##set) |
28f540f4 | 324 | |
dfd2257a | 325 | # else /* Not ELF: a.out. */ |
28f540f4 | 326 | |
5af3245a UD |
327 | # ifdef HAVE_XCOFF |
328 | /* XCOFF does not support .stabs. | |
329 | The native aix linker will remove the .stab and .stabstr sections | |
330 | The gnu linker will have a fatal error if there is a relocation for | |
331 | symbol in the .stab section. Silently disable these macros. */ | |
7969407a UD |
332 | # define text_set_element(set, symbol) |
333 | # define data_set_element(set, symbol) | |
334 | # define bss_set_element(set, symbol) | |
5af3245a UD |
335 | # else |
336 | # define text_set_element(set, symbol) \ | |
337 | asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol) | |
338 | # define data_set_element(set, symbol) \ | |
339 | asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol) | |
340 | # define bss_set_element(set, symbol) ?error Must use initialized data. | |
341 | # endif /* XCOFF */ | |
dfd2257a | 342 | # define symbol_set_define(set) void *const (set)[1]; |
03df72bf | 343 | # define symbol_set_declare(set) extern void *const (set)[1]; |
28f540f4 | 344 | |
dfd2257a UD |
345 | # define symbol_set_first_element(set) &(set)[1] |
346 | # define symbol_set_end_p(set, ptr) (*(ptr) == 0) | |
28f540f4 | 347 | |
dfd2257a | 348 | # endif /* ELF. */ |
a2a89dd6 UD |
349 | #else |
350 | /* We cannot do anything in generial. */ | |
351 | # define text_set_element(set, symbol) asm ("") | |
352 | # define data_set_element(set, symbol) asm ("") | |
353 | # define bss_set_element(set, symbol) asm ("") | |
354 | # define symbol_set_define(set) void *const (set)[1]; | |
355 | # define symbol_set_declare(set) extern void *const (set)[1]; | |
356 | ||
357 | # define symbol_set_first_element(set) &(set)[1] | |
358 | # define symbol_set_end_p(set, ptr) (*(ptr) == 0) | |
28f540f4 RM |
359 | #endif /* Have GNU ld. */ |
360 | ||
1ea89a40 | 361 | #if DO_VERSIONING |
ebdf53a7 | 362 | # define symbol_version(real, name, version) \ |
8b943b4a | 363 | _symbol_version(real, name, version) |
ebdf53a7 GM |
364 | # define default_symbol_version(real, name, version) \ |
365 | _default_symbol_version(real, name, version) | |
366 | # ifdef __ASSEMBLER__ | |
8b943b4a | 367 | # define _symbol_version(real, name, version) \ |
da2d1bc5 | 368 | .symver real, name##@##version |
8b943b4a | 369 | # define _default_symbol_version(real, name, version) \ |
da2d1bc5 UD |
370 | .symver real, name##@##@##version |
371 | # else | |
8b943b4a | 372 | # define _symbol_version(real, name, version) \ |
1ea89a40 | 373 | __asm__ (".symver " #real "," #name "@" #version) |
8b943b4a | 374 | # define _default_symbol_version(real, name, version) \ |
f2ea0f5b | 375 | __asm__ (".symver " #real "," #name "@@" #version) |
da2d1bc5 | 376 | # endif |
1ea89a40 UD |
377 | #else |
378 | # define symbol_version(real, name, version) | |
da2d1bc5 UD |
379 | # define default_symbol_version(real, name, version) \ |
380 | strong_alias(real, name) | |
1ea89a40 UD |
381 | #endif |
382 | ||
e6caf4e1 UD |
383 | #if defined HAVE_VISIBILITY_ATTRIBUTE && defined SHARED |
384 | # define attribute_hidden __attribute__ ((visibility ("hidden"))) | |
385 | #else | |
386 | # define attribute_hidden | |
387 | #endif | |
388 | ||
7969407a UD |
389 | /* Handling on non-exported internal names. We have to do this only |
390 | for shared code. */ | |
391 | #ifdef SHARED | |
cff26a3e | 392 | # define INTUSE(name) name##_internal |
e6caf4e1 UD |
393 | # define INTDEF(name) strong_alias (name, name##_internal) |
394 | # define INTVARDEF(name) \ | |
1897bc3f | 395 | _INTVARDEF (name, name##_internal) |
7f0244de AJ |
396 | # if defined HAVE_VISIBILITY_ATTRIBUTE |
397 | # define _INTVARDEF(name, aliasname) \ | |
100351c3 UD |
398 | extern __typeof (name) aliasname __attribute__ ((alias (#name), \ |
399 | visibility ("hidden"))); | |
7f0244de AJ |
400 | # else |
401 | # define _INTVARDEF(name, aliasname) \ | |
402 | extern __typeof (name) aliasname __attribute__ ((alias (#name))); | |
403 | # endif | |
e6caf4e1 | 404 | # define INTDEF2(name, newname) strong_alias (name, newname##_internal) |
1897bc3f | 405 | # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal) |
7969407a | 406 | #else |
cff26a3e | 407 | # define INTUSE(name) name |
7969407a | 408 | # define INTDEF(name) |
e6caf4e1 | 409 | # define INTVARDEF(name) |
77fe0b9c | 410 | # define INTDEF2(name, newname) |
1897bc3f | 411 | # define INTVARDEF2(name, newname) |
7969407a UD |
412 | #endif |
413 | ||
37ba7d66 UD |
414 | /* The following macros are used for PLT bypassing within libc.so |
415 | (and if needed other libraries similarly). | |
416 | First of all, you need to have the function prototyped somewhere, | |
417 | say in foo/foo.h: | |
418 | ||
419 | int foo (int __bar); | |
420 | ||
421 | If calls to foo within libc.so should always go to foo defined in libc.so, | |
422 | then in include/foo.h you add: | |
423 | ||
424 | libc_hidden_proto (foo) | |
425 | ||
426 | line and after the foo function definition: | |
427 | ||
428 | int foo (int __bar) | |
429 | { | |
430 | return __bar; | |
431 | } | |
432 | libc_hidden_def (foo) | |
433 | ||
434 | or | |
435 | ||
436 | int foo (int __bar) | |
437 | { | |
438 | return __bar; | |
439 | } | |
440 | libc_hidden_weak (foo) | |
441 | ||
442 | If foo is normally just an alias (strong or weak) of some other function, | |
443 | you should use the normal strong_alias first, then add libc_hidden_def | |
444 | or libc_hidden_weak: | |
445 | ||
446 | int baz (int __bar) | |
447 | { | |
448 | return __bar; | |
449 | } | |
450 | strong_alias (baz, foo) | |
451 | libc_hidden_weak (foo) | |
452 | ||
453 | If the function should be internal to multiple objects, say ld.so and | |
454 | libc.so, the best way is to use: | |
455 | ||
456 | #if !defined NOT_IN_libc || defined IS_IN_rtld | |
457 | hidden_proto (foo) | |
458 | #endif | |
459 | ||
460 | in include/foo.h and the normal macros at all function definitions | |
461 | depending on what DSO they belong to. | |
462 | ||
463 | If versioned_symbol macro is used to define foo, | |
464 | libc_hidden_ver macro should be used, as in: | |
465 | ||
466 | int __real_foo (int __bar) | |
467 | { | |
468 | return __bar; | |
469 | } | |
470 | versioned_symbol (libc, __real_foo, foo, GLIBC_2_1); | |
471 | libc_hidden_ver (__real_foo, foo) */ | |
472 | ||
2b29b5ac UD |
473 | #if defined SHARED && defined DO_VERSIONING \ |
474 | && !defined HAVE_BROKEN_ALIAS_ATTRIBUTE | |
37ba7d66 UD |
475 | # ifndef __ASSEMBLER__ |
476 | # ifdef HAVE_BROKEN_VISIBILITY_ATTRIBUTE | |
477 | # define __hidden_proto_hiddenattr | |
478 | # else | |
479 | # define __hidden_proto_hiddenattr attribute_hidden | |
480 | # endif | |
2b29b5ac | 481 | # define hidden_proto(name) __hidden_proto (name, __GI_##name) |
37ba7d66 | 482 | # define __hidden_proto(name, internal) \ |
a585ba22 RM |
483 | extern __typeof (name) internal; \ |
484 | extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \ | |
37ba7d66 UD |
485 | __hidden_proto_hiddenattr; |
486 | # define __hidden_asmname(name) \ | |
487 | __hidden_asmname1 (__USER_LABEL_PREFIX__, name) | |
488 | # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name) | |
489 | # define __hidden_asmname2(prefix, name) #prefix name | |
490 | # ifdef HAVE_ASM_SET_DIRECTIVE | |
491 | # define __hidden_def1(original, alias) \ | |
492 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
493 | .set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) | |
494 | # else | |
495 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME | |
496 | # define __hidden_def1(original, alias) \ | |
497 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
498 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
499 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
500 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) | |
501 | # else | |
502 | # define __hidden_def1(original, alias) \ | |
503 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
504 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) | |
505 | # endif | |
506 | # endif | |
507 | # define __hidden_def2(...) #__VA_ARGS__ | |
508 | # define __hidden_def3(...) __hidden_def2 (__VA_ARGS__) | |
509 | # define hidden_def(name) \ | |
510 | __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name))); | |
511 | # define hidden_ver(local, name) \ | |
512 | __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name))); | |
513 | # ifdef HAVE_WEAK_SYMBOLS | |
514 | # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE | |
515 | # define __hidden_weak1(original, alias) \ | |
516 | .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) | |
517 | # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ | |
518 | # ifdef HAVE_ASM_GLOBAL_DOT_NAME | |
519 | # define __hidden_weak1(original, alias) \ | |
520 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
521 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ | |
522 | ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ | |
523 | C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) | |
524 | # else | |
525 | # define __hidden_weak1(original, alias) \ | |
526 | .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ | |
527 | C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) | |
528 | # endif | |
529 | # endif | |
530 | # define hidden_weak(name) \ | |
531 | __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name))); | |
532 | # else | |
533 | # define hidden_weak(name) hidden_def (name) | |
534 | # endif | |
535 | # else | |
536 | /* For assembly, we need to do the opposite of what we do in C: | |
537 | in assembly gcc __REDIRECT stuff is not in place, so functions | |
538 | are defined by its normal name and we need to create the | |
539 | __GI_* alias to it, in C __REDIRECT causes the function definition | |
540 | to use __GI_* name and we need to add alias to the real name. | |
4547dee3 RM |
541 | There is no reason to use hidden_weak over hidden_def in assembly, |
542 | but we provide it for consistency with the C usage. | |
543 | hidden_proto doesn't make sense for assembly but the equivalent | |
544 | is to call via the HIDDEN_JUMPTARGET macro einstead of JUMPTARGET. */ | |
545 | # define hidden_def(name) strong_alias (name, __GI_##name) | |
546 | # define hidden_weak(name) hidden_def (name) | |
37ba7d66 | 547 | # define hidden_ver(local, name) strong_alias (local, __GI_##name) |
4547dee3 | 548 | # define HIDDEN_JUMPTARGET(name) __GI_##name |
37ba7d66 UD |
549 | # endif |
550 | #else | |
4547dee3 | 551 | # ifndef __ASSEMBLER__ |
37ba7d66 | 552 | # define hidden_proto(name) |
4547dee3 RM |
553 | # else |
554 | # define HIDDEN_JUMPTARGET(name) JUMPTARGET(name) | |
555 | # endif /* Not __ASSEMBLER__ */ | |
556 | # define hidden_weak(name) | |
37ba7d66 UD |
557 | # define hidden_def(name) |
558 | # define hidden_ver(local, name) | |
559 | #endif | |
560 | ||
c5598d47 | 561 | #if !defined NOT_IN_libc |
37ba7d66 UD |
562 | # define libc_hidden_proto(name) hidden_proto (name) |
563 | # define libc_hidden_def(name) hidden_def (name) | |
564 | # define libc_hidden_weak(name) hidden_weak (name) | |
565 | # define libc_hidden_ver(local, name) hidden_ver (local, name) | |
566 | #else | |
567 | # define libc_hidden_proto(name) | |
568 | # define libc_hidden_def(name) | |
569 | # define libc_hidden_weak(name) | |
570 | # define libc_hidden_ver(local, name) | |
571 | #endif | |
572 | ||
c5598d47 | 573 | #if defined NOT_IN_libc && defined IS_IN_rtld |
37ba7d66 UD |
574 | # define rtld_hidden_proto(name) hidden_proto (name) |
575 | # define rtld_hidden_def(name) hidden_def (name) | |
576 | # define rtld_hidden_weak(name) hidden_weak (name) | |
577 | # define rtld_hidden_ver(local, name) hidden_ver (local, name) | |
578 | #else | |
579 | # define rtld_hidden_proto(name) | |
580 | # define rtld_hidden_def(name) | |
581 | # define rtld_hidden_weak(name) | |
582 | # define rtld_hidden_ver(local, name) | |
583 | #endif | |
584 | ||
c5598d47 | 585 | #if defined NOT_IN_libc && defined IS_IN_libm |
37ba7d66 UD |
586 | # define libm_hidden_proto(name) hidden_proto (name) |
587 | # define libm_hidden_def(name) hidden_def (name) | |
588 | # define libm_hidden_weak(name) hidden_weak (name) | |
589 | # define libm_hidden_ver(local, name) hidden_ver (local, name) | |
590 | #else | |
591 | # define libm_hidden_proto(name) | |
592 | # define libm_hidden_def(name) | |
593 | # define libm_hidden_weak(name) | |
594 | # define libm_hidden_ver(local, name) | |
595 | #endif | |
596 | ||
28f540f4 | 597 | #endif /* libc-symbols.h */ |