Nuke USB_DO_ATTACH and remove device_t dv, since it is no longer needed.
[dragonfly.git] / contrib / gcc-3.4 / gcc / crtstuff.c
blob580ee3c9c92e4dcd9ce1729a5e83266f40a8520b
1 /* Specialized bits of code needed to support construction and
2 destruction of file-scope objects in C++ code.
3 Copyright (C) 1991, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 Contributed by Ron Guilmette (rfg@monkeys.com).
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
12 version.
14 In addition to the permissions in the GNU General Public License, the
15 Free Software Foundation gives you unlimited permission to link the
16 compiled version of this file into combinations with other programs,
17 and to distribute those combinations without any restriction coming
18 from the use of this file. (The General Public License restrictions
19 do apply in other respects; for example, they cover modification of
20 the file, and distribution when not linked into a combine
21 executable.)
23 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
24 WARRANTY; without even the implied warranty of MERCHANTABILITY or
25 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
26 for more details.
28 You should have received a copy of the GNU General Public License
29 along with GCC; see the file COPYING. If not, write to the Free
30 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
31 02111-1307, USA. */
33 /* This file is a bit like libgcc2.c in that it is compiled
34 multiple times and yields multiple .o files.
36 This file is useful on target machines where the object file format
37 supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE). On
38 such systems, this file allows us to avoid running collect (or any
39 other such slow and painful kludge). Additionally, if the target
40 system supports a .init section, this file allows us to support the
41 linking of C++ code with a non-C++ main program.
43 Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then
44 this file *will* make use of the .init section. If that symbol is
45 not defined however, then the .init section will not be used.
47 Currently, only ELF and COFF are supported. It is likely however that
48 ROSE could also be supported, if someone was willing to do the work to
49 make whatever (small?) adaptations are needed. (Some work may be
50 needed on the ROSE assembler and linker also.)
52 This file must be compiled with gcc. */
54 /* It is incorrect to include config.h here, because this file is being
55 compiled for the target, and hence definitions concerning only the host
56 do not apply. */
58 /* We include auto-host.h here to get HAVE_GAS_HIDDEN. This is
59 supposedly valid even though this is a "target" file. */
60 #include "auto-host.h"
61 #include "tconfig.h"
62 #include "tsystem.h"
63 #include "coretypes.h"
64 #include "tm.h"
65 #include "unwind-dw2-fde.h"
67 #ifndef FORCE_CODE_SECTION_ALIGN
68 # define FORCE_CODE_SECTION_ALIGN
69 #endif
71 #ifndef CRT_CALL_STATIC_FUNCTION
72 # define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \
73 static void __attribute__((__used__)) \
74 call_ ## FUNC (void) \
75 { \
76 asm (SECTION_OP); \
77 FUNC (); \
78 FORCE_CODE_SECTION_ALIGN \
79 asm (TEXT_SECTION_ASM_OP); \
81 #endif
83 #if defined(OBJECT_FORMAT_ELF) && defined(HAVE_LD_EH_FRAME_HDR) \
84 && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
85 && defined(__GLIBC__) && __GLIBC__ >= 2
86 #include <link.h>
87 # if (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
88 || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
89 # define USE_PT_GNU_EH_FRAME
90 # endif
91 #endif
92 #if defined(EH_FRAME_SECTION_NAME) && !defined(USE_PT_GNU_EH_FRAME)
93 # define USE_EH_FRAME_REGISTRY
94 #endif
95 #if defined(EH_FRAME_SECTION_NAME) && defined(HAVE_LD_RO_RW_SECTION_MIXING)
96 # define EH_FRAME_SECTION_CONST const
97 #else
98 # define EH_FRAME_SECTION_CONST
99 #endif
101 /* We do not want to add the weak attribute to the declarations of these
102 routines in unwind-dw2-fde.h because that will cause the definition of
103 these symbols to be weak as well.
105 This exposes a core issue, how to handle creating weak references vs
106 how to create weak definitions. Either we have to have the definition
107 of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
108 have a second declaration if we want a function's references to be weak,
109 but not its definition.
111 Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
112 one thinks about scaling to larger problems -- ie, the condition under
113 which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
114 complicated.
116 So, we take an approach similar to #pragma weak -- we have a second
117 declaration for functions that we want to have weak references.
119 Neither way is particularly good. */
121 /* References to __register_frame_info and __deregister_frame_info should
122 be weak in this file if at all possible. */
123 extern void __register_frame_info (const void *, struct object *)
124 TARGET_ATTRIBUTE_WEAK;
125 extern void __register_frame_info_bases (const void *, struct object *,
126 void *, void *)
127 TARGET_ATTRIBUTE_WEAK;
128 extern void *__deregister_frame_info (const void *)
129 TARGET_ATTRIBUTE_WEAK;
130 extern void *__deregister_frame_info_bases (const void *)
131 TARGET_ATTRIBUTE_WEAK;
132 extern void __do_global_ctors_1 (void);
134 /* Likewise for _Jv_RegisterClasses. */
135 extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
137 #ifdef OBJECT_FORMAT_ELF
139 /* Declare a pointer to void function type. */
140 typedef void (*func_ptr) (void);
141 #define STATIC static
143 #else /* OBJECT_FORMAT_ELF */
145 #include "gbl-ctors.h"
147 #define STATIC
149 #endif /* OBJECT_FORMAT_ELF */
151 #ifdef CRT_BEGIN
153 /* NOTE: In order to be able to support SVR4 shared libraries, we arrange
154 to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
155 __DTOR_END__ } per root executable and also one set of these symbols
156 per shared library. So in any given whole process image, we may have
157 multiple definitions of each of these symbols. In order to prevent
158 these definitions from conflicting with one another, and in order to
159 ensure that the proper lists are used for the initialization/finalization
160 of each individual shared library (respectively), we give these symbols
161 only internal (i.e. `static') linkage, and we also make it a point to
162 refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
163 symbol in crtbegin.o, where they are defined. */
165 /* The -1 is a flag to __do_global_[cd]tors indicating that this table
166 does not start with a count of elements. */
167 #ifdef CTOR_LIST_BEGIN
168 CTOR_LIST_BEGIN;
169 #elif defined(CTORS_SECTION_ASM_OP)
170 /* Hack: force cc1 to switch to .data section early, so that assembling
171 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */
172 static func_ptr force_to_data[1] __attribute__ ((__unused__)) = { };
173 asm (CTORS_SECTION_ASM_OP);
174 STATIC func_ptr __CTOR_LIST__[1]
175 __attribute__ ((__unused__, aligned(sizeof(func_ptr))))
176 = { (func_ptr) (-1) };
177 #else
178 STATIC func_ptr __CTOR_LIST__[1]
179 __attribute__ ((__unused__, section(".ctors"), aligned(sizeof(func_ptr))))
180 = { (func_ptr) (-1) };
181 #endif /* __CTOR_LIST__ alternatives */
183 #ifdef DTOR_LIST_BEGIN
184 DTOR_LIST_BEGIN;
185 #elif defined(DTORS_SECTION_ASM_OP)
186 asm (DTORS_SECTION_ASM_OP);
187 STATIC func_ptr __DTOR_LIST__[1]
188 __attribute__ ((aligned(sizeof(func_ptr))))
189 = { (func_ptr) (-1) };
190 #else
191 STATIC func_ptr __DTOR_LIST__[1]
192 __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
193 = { (func_ptr) (-1) };
194 #endif /* __DTOR_LIST__ alternatives */
196 #ifdef USE_EH_FRAME_REGISTRY
197 /* Stick a label at the beginning of the frame unwind info so we can register
198 and deregister it with the exception handling library code. */
199 STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
200 __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
201 = { };
202 #endif /* USE_EH_FRAME_REGISTRY */
204 #ifdef JCR_SECTION_NAME
205 /* Stick a label at the beginning of the java class registration info
206 so we can register them properly. */
207 STATIC void *__JCR_LIST__[]
208 __attribute__ ((unused, section(JCR_SECTION_NAME), aligned(sizeof(void*))))
209 = { };
210 #endif /* JCR_SECTION_NAME */
212 #ifdef INIT_SECTION_ASM_OP
214 #ifdef OBJECT_FORMAT_ELF
216 /* Declare the __dso_handle variable. It should have a unique value
217 in every shared-object; in a main program its value is zero. The
218 object should in any case be protected. This means the instance
219 in one DSO or the main program is not used in another object. The
220 dynamic linker takes care of this. */
222 #ifdef HAVE_GAS_HIDDEN
223 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
224 #endif
225 #ifdef CRTSTUFFS_O
226 void *__dso_handle = &__dso_handle;
227 #else
228 void *__dso_handle = 0;
229 #endif
231 /* The __cxa_finalize function may not be available so we use only a
232 weak declaration. */
233 extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
235 /* Run all the global destructors on exit from the program. */
237 /* Some systems place the number of pointers in the first word of the
238 table. On SVR4 however, that word is -1. In all cases, the table is
239 null-terminated. On SVR4, we start from the beginning of the list and
240 invoke each per-compilation-unit destructor routine in order
241 until we find that null.
243 Note that this function MUST be static. There will be one of these
244 functions in each root executable and one in each shared library, but
245 although they all have the same code, each one is unique in that it
246 refers to one particular associated `__DTOR_LIST__' which belongs to the
247 same particular root executable or shared library file.
249 On some systems, this routine is run more than once from the .fini,
250 when exit is called recursively, so we arrange to remember where in
251 the list we left off processing, and we resume at that point,
252 should we be re-invoked. */
254 static void __attribute__((used))
255 __do_global_dtors_aux (void)
257 static func_ptr *p = __DTOR_LIST__ + 1;
258 static _Bool completed;
259 func_ptr f;
261 if (__builtin_expect (completed, 0))
262 return;
264 #ifdef CRTSTUFFS_O
265 if (__cxa_finalize)
266 __cxa_finalize (__dso_handle);
267 #endif
269 while ((f = *p))
271 p++;
272 f ();
275 #ifdef USE_EH_FRAME_REGISTRY
276 #ifdef CRT_GET_RFIB_DATA
277 /* If we used the new __register_frame_info_bases interface,
278 make sure that we deregister from the same place. */
279 if (__deregister_frame_info_bases)
280 __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
281 #else
282 if (__deregister_frame_info)
283 __deregister_frame_info (__EH_FRAME_BEGIN__);
284 #endif
285 #endif
287 completed = 1;
290 /* Stick a call to __do_global_dtors_aux into the .fini section. */
291 CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
293 #if defined(USE_EH_FRAME_REGISTRY) || defined(JCR_SECTION_NAME)
294 /* Stick a call to __register_frame_info into the .init section. For some
295 reason calls with no arguments work more reliably in .init, so stick the
296 call in another function. */
298 static void __attribute__((used))
299 frame_dummy (void)
301 #ifdef USE_EH_FRAME_REGISTRY
302 static struct object object;
303 #ifdef CRT_GET_RFIB_DATA
304 void *tbase, *dbase;
305 tbase = 0;
306 CRT_GET_RFIB_DATA (dbase);
307 if (__register_frame_info_bases)
308 __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
309 #else
310 if (__register_frame_info)
311 __register_frame_info (__EH_FRAME_BEGIN__, &object);
312 #endif /* CRT_GET_RFIB_DATA */
313 #endif /* USE_EH_FRAME_REGISTRY */
314 #ifdef JCR_SECTION_NAME
315 if (__JCR_LIST__[0] && _Jv_RegisterClasses)
316 _Jv_RegisterClasses (__JCR_LIST__);
317 #endif /* JCR_SECTION_NAME */
320 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, frame_dummy)
321 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME */
323 #else /* OBJECT_FORMAT_ELF */
325 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
326 and once in crtend.o). It must be declared static to avoid a link
327 error. Here, we define __do_global_ctors as an externally callable
328 function. It is externally callable so that __main can invoke it when
329 INVOKE__main is defined. This has the additional effect of forcing cc1
330 to switch to the .text section. */
332 static void __do_global_ctors_aux (void);
333 void
334 __do_global_ctors (void)
336 #ifdef INVOKE__main
337 /* If __main won't actually call __do_global_ctors then it doesn't matter
338 what's inside the function. The inside of __do_global_ctors_aux is
339 called automatically in that case. And the Alliant fx2800 linker
340 crashes on this reference. So prevent the crash. */
341 __do_global_ctors_aux ();
342 #endif
345 asm (INIT_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */
347 /* A routine to invoke all of the global constructors upon entry to the
348 program. We put this into the .init section (for systems that have
349 such a thing) so that we can properly perform the construction of
350 file-scope static-storage C++ objects within shared libraries. */
352 static void __attribute__((used))
353 __do_global_ctors_aux (void) /* prologue goes in .init section */
355 FORCE_CODE_SECTION_ALIGN /* explicit align before switch to .text */
356 asm (TEXT_SECTION_ASM_OP); /* don't put epilogue and body in .init */
357 DO_GLOBAL_CTORS_BODY;
358 atexit (__do_global_dtors);
361 #endif /* OBJECT_FORMAT_ELF */
363 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
365 extern void __do_global_dtors (void);
367 /* This case is used by the Irix 6 port, which supports named sections but
368 not an SVR4-style .fini section. __do_global_dtors can be non-static
369 in this case because we protect it with -hidden_symbol. */
371 void
372 __do_global_dtors (void)
374 func_ptr *p, f;
375 for (p = __DTOR_LIST__ + 1; (f = *p); p++)
376 f ();
378 #ifdef USE_EH_FRAME_REGISTRY
379 if (__deregister_frame_info)
380 __deregister_frame_info (__EH_FRAME_BEGIN__);
381 #endif
384 #if defined(USE_EH_FRAME_REGISTRY) || defined(JCR_SECTION_NAME)
385 /* A helper function for __do_global_ctors, which is in crtend.o. Here
386 in crtbegin.o, we can reference a couple of symbols not visible there.
387 Plus, since we're before libgcc.a, we have no problems referencing
388 functions from there. */
389 void
390 __do_global_ctors_1(void)
392 #ifdef USE_EH_FRAME_REGISTRY
393 static struct object object;
394 if (__register_frame_info)
395 __register_frame_info (__EH_FRAME_BEGIN__, &object);
396 #endif
397 #ifdef JCR_SECTION_NAME
398 if (__JCR_LIST__[0] && _Jv_RegisterClasses)
399 _Jv_RegisterClasses (__JCR_LIST__);
400 #endif
402 #endif /* USE_EH_FRAME_REGISTRY || JCR_SECTION_NAME */
404 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
405 #error "What are you doing with crtstuff.c, then?"
406 #endif
408 #elif defined(CRT_END) /* ! CRT_BEGIN */
410 /* Put a word containing zero at the end of each of our two lists of function
411 addresses. Note that the words defined here go into the .ctors and .dtors
412 sections of the crtend.o file, and since that file is always linked in
413 last, these words naturally end up at the very ends of the two lists
414 contained in these two sections. */
416 #ifdef CTOR_LIST_END
417 CTOR_LIST_END;
418 #elif defined(CTORS_SECTION_ASM_OP)
419 /* Hack: force cc1 to switch to .data section early, so that assembling
420 __CTOR_LIST__ does not undo our behind-the-back change to .ctors. */
421 static func_ptr force_to_data[1] __attribute__ ((__unused__)) = { };
422 asm (CTORS_SECTION_ASM_OP);
423 STATIC func_ptr __CTOR_END__[1]
424 __attribute__((aligned(sizeof(func_ptr))))
425 = { (func_ptr) 0 };
426 #else
427 STATIC func_ptr __CTOR_END__[1]
428 __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
429 = { (func_ptr) 0 };
430 #endif
432 #ifdef DTOR_LIST_END
433 DTOR_LIST_END;
434 #elif defined(DTORS_SECTION_ASM_OP)
435 asm (DTORS_SECTION_ASM_OP);
436 STATIC func_ptr __DTOR_END__[1]
437 __attribute__ ((unused, aligned(sizeof(func_ptr))))
438 = { (func_ptr) 0 };
439 #else
440 STATIC func_ptr __DTOR_END__[1]
441 __attribute__((unused, section(".dtors"), aligned(sizeof(func_ptr))))
442 = { (func_ptr) 0 };
443 #endif
445 #ifdef EH_FRAME_SECTION_NAME
446 /* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
447 this would be the 'length' field in a real FDE. */
448 # if __INT_MAX__ == 2147483647
449 typedef int int32;
450 # elif __LONG_MAX__ == 2147483647
451 typedef long int32;
452 # elif __SHRT_MAX__ == 2147483647
453 typedef short int32;
454 # else
455 # error "Missing a 4 byte integer"
456 # endif
457 STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
458 __attribute__ ((unused, section(EH_FRAME_SECTION_NAME),
459 aligned(sizeof(int32))))
460 = { 0 };
461 #endif /* EH_FRAME_SECTION_NAME */
463 #ifdef JCR_SECTION_NAME
464 /* Null terminate the .jcr section array. */
465 STATIC void *__JCR_END__[1]
466 __attribute__ ((unused, section(JCR_SECTION_NAME),
467 aligned(sizeof(void *))))
468 = { 0 };
469 #endif /* JCR_SECTION_NAME */
471 #ifdef INIT_SECTION_ASM_OP
473 #ifdef OBJECT_FORMAT_ELF
474 static void __attribute__((used))
475 __do_global_ctors_aux (void)
477 func_ptr *p;
478 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
479 (*p) ();
482 /* Stick a call to __do_global_ctors_aux into the .init section. */
483 CRT_CALL_STATIC_FUNCTION (INIT_SECTION_ASM_OP, __do_global_ctors_aux)
484 #else /* OBJECT_FORMAT_ELF */
486 /* Stick the real initialization code, followed by a normal sort of
487 function epilogue at the very end of the .init section for this
488 entire root executable file or for this entire shared library file.
490 Note that we use some tricks here to get *just* the body and just
491 a function epilogue (but no function prologue) into the .init
492 section of the crtend.o file. Specifically, we switch to the .text
493 section, start to define a function, and then we switch to the .init
494 section just before the body code.
496 Earlier on, we put the corresponding function prologue into the .init
497 section of the crtbegin.o file (which will be linked in first).
499 Note that we want to invoke all constructors for C++ file-scope static-
500 storage objects AFTER any other possible initialization actions which
501 may be performed by the code in the .init section contributions made by
502 other libraries, etc. That's because those other initializations may
503 include setup operations for very primitive things (e.g. initializing
504 the state of the floating-point coprocessor, etc.) which should be done
505 before we start to execute any of the user's code. */
507 static void
508 __do_global_ctors_aux (void) /* prologue goes in .text section */
510 asm (INIT_SECTION_ASM_OP);
511 DO_GLOBAL_CTORS_BODY;
512 atexit (__do_global_dtors);
513 } /* epilogue and body go in .init section */
515 FORCE_CODE_SECTION_ALIGN
516 asm (TEXT_SECTION_ASM_OP);
518 #endif /* OBJECT_FORMAT_ELF */
520 #elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
522 extern void __do_global_ctors (void);
524 /* This case is used by the Irix 6 port, which supports named sections but
525 not an SVR4-style .init section. __do_global_ctors can be non-static
526 in this case because we protect it with -hidden_symbol. */
527 void
528 __do_global_ctors (void)
530 func_ptr *p;
531 #if defined(USE_EH_FRAME_REGISTRY) || defined(JCR_SECTION_NAME)
532 __do_global_ctors_1();
533 #endif
534 for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
535 (*p) ();
538 #else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
539 #error "What are you doing with crtstuff.c, then?"
540 #endif
542 #else /* ! CRT_BEGIN && ! CRT_END */
543 #error "One of CRT_BEGIN or CRT_END must be defined."
544 #endif