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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/config/darwin-crt3.c | |
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Diffstat (limited to 'gcc/config/darwin-crt3.c')
-rw-r--r-- | gcc/config/darwin-crt3.c | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/gcc/config/darwin-crt3.c b/gcc/config/darwin-crt3.c new file mode 100644 index 000000000..9b64f2aa8 --- /dev/null +++ b/gcc/config/darwin-crt3.c @@ -0,0 +1,532 @@ +/* __cxa_atexit backwards-compatibility support for Darwin. + Copyright (C) 2006, 2009 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +/* Don't do anything if we are compiling for a kext multilib. */ +#ifdef __PIC__ + +/* It is incorrect to include config.h here, because this file is being + compiled for the target, and hence definitions concerning only the host + do not apply. */ + +#include "tconfig.h" +#include "tsystem.h" + +#include <dlfcn.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> + +/* This file works around two different problems. + + The first problem is that there is no __cxa_atexit on Mac OS versions + before 10.4. It fixes this by providing a complete atexit and + __cxa_atexit emulation called from the regular atexit. + + The second problem is that on all shipping versions of Mac OS, + __cxa_finalize and exit() don't work right: they don't run routines + that were registered while other atexit routines are running. This + is worked around by wrapping each atexit/__cxa_atexit routine with + our own routine which ensures that any __cxa_atexit calls while it + is running are honoured. + + There are still problems which this does not solve. Before 10.4, + shared objects linked with previous compilers won't have their + atexit calls properly interleaved with code compiled with newer + compilers. Also, atexit routines registered from shared objects + linked with previous compilers won't get the bug fix. */ + +typedef int (*cxa_atexit_p)(void (*func) (void*), void* arg, const void* dso); +typedef void (*cxa_finalize_p)(const void *dso); +typedef int (*atexit_p)(void (*func)(void)); + +/* These are from "keymgr.h". */ +extern void *_keymgr_get_and_lock_processwide_ptr (unsigned key); +extern int _keymgr_get_and_lock_processwide_ptr_2 (unsigned, void **); +extern int _keymgr_set_and_unlock_processwide_ptr (unsigned key, void *ptr); + +extern void *__keymgr_global[]; +typedef struct _Sinfo_Node { + unsigned int size ; /*size of this node*/ + unsigned short major_version ; /*API major version.*/ + unsigned short minor_version ; /*API minor version.*/ + } _Tinfo_Node ; + +#ifdef __ppc__ +#define CHECK_KEYMGR_ERROR(e) \ + (((_Tinfo_Node *)__keymgr_global[2])->major_version >= 4 ? (e) : 0) +#else +#define CHECK_KEYMGR_ERROR(e) (e) +#endif + +/* Our globals are stored under this keymgr index. */ +#define KEYMGR_ATEXIT_LIST 14 + +/* The different kinds of callback routines. */ +typedef void (*atexit_callback)(void); +typedef void (*cxa_atexit_callback)(void *); + +/* This structure holds a routine to call. There may be extra fields + at the end of the structure that this code doesn't know about. */ +struct one_atexit_routine +{ + union { + atexit_callback ac; + cxa_atexit_callback cac; + } callback; + /* has_arg is 0/2/4 if 'ac' is live, 1/3/5 if 'cac' is live. + Higher numbers indicate a later version of the structure that this + code doesn't understand and will ignore. */ + int has_arg; + void * arg; +}; + +struct atexit_routine_list +{ + struct atexit_routine_list * next; + struct one_atexit_routine r; +}; + +/* The various possibilities for status of atexit(). */ +enum atexit_status { + atexit_status_unknown = 0, + atexit_status_missing = 1, + atexit_status_broken = 2, + atexit_status_working = 16 +}; + +struct keymgr_atexit_list +{ + /* Version of this list. This code knows only about version 0. + If the version is higher than 0, this code may add new atexit routines + but should not attempt to run the list. */ + short version; + /* 1 if an atexit routine is currently being run by this code, 0 + otherwise. */ + char running_routines; + /* Holds a value from 'enum atexit_status'. */ + unsigned char atexit_status; + /* The list of atexit and cxa_atexit routines registered. If + atexit_status_missing it contains all routines registered while + linked with this code. If atexit_status_broken it contains all + routines registered during cxa_finalize while linked with this + code. */ + struct atexit_routine_list *l; + /* &__cxa_atexit; set if atexit_status >= atexit_status_broken. */ + cxa_atexit_p cxa_atexit_f; + /* &__cxa_finalize; set if atexit_status >= atexit_status_broken. */ + cxa_finalize_p cxa_finalize_f; + /* &atexit; set if atexit_status >= atexit_status_working + or atexit_status == atexit_status_missing. */ + atexit_p atexit_f; +}; + +/* Return 0 if __cxa_atexit has the bug it has in Mac OS 10.4: it + fails to call routines registered while an atexit routine is + running. Return 1 if it works properly, and -1 if an error occurred. */ + +struct atexit_data +{ + int result; + cxa_atexit_p cxa_atexit; +}; + +static void cxa_atexit_check_2 (void *arg) +{ + ((struct atexit_data *)arg)->result = 1; +} + +static void cxa_atexit_check_1 (void *arg) +{ + struct atexit_data * aed = arg; + if (aed->cxa_atexit (cxa_atexit_check_2, arg, arg) != 0) + aed->result = -1; +} + +static int +check_cxa_atexit (cxa_atexit_p cxa_atexit, cxa_finalize_p cxa_finalize) +{ + struct atexit_data aed = { 0, cxa_atexit }; + + /* We re-use &aed as the 'dso' parameter, since it's a unique address. */ + if (cxa_atexit (cxa_atexit_check_1, &aed, &aed) != 0) + return -1; + cxa_finalize (&aed); + if (aed.result == 0) + { + /* Call __cxa_finalize again to make sure that cxa_atexit_check_2 + is removed from the list before AED goes out of scope. */ + cxa_finalize (&aed); + aed.result = 0; + } + return aed.result; +} + +#ifdef __ppc__ +/* This comes from Csu. It works only before 10.4. The prototype has + been altered a bit to avoid casting. */ +extern int _dyld_func_lookup(const char *dyld_func_name, + void *address) __attribute__((visibility("hidden"))); + +static void our_atexit (void); + +/* We're running on 10.3.9. Find the address of the system atexit() + function. So easy to say, so hard to do. */ +static atexit_p +find_atexit_10_3 (void) +{ + unsigned int (*dyld_image_count_fn)(void); + const char *(*dyld_get_image_name_fn)(unsigned int image_index); + const void *(*dyld_get_image_header_fn)(unsigned int image_index); + const void *(*NSLookupSymbolInImage_fn)(const void *image, + const char *symbolName, + unsigned int options); + void *(*NSAddressOfSymbol_fn)(const void *symbol); + unsigned i, count; + + /* Find some dyld functions. */ + _dyld_func_lookup("__dyld_image_count", &dyld_image_count_fn); + _dyld_func_lookup("__dyld_get_image_name", &dyld_get_image_name_fn); + _dyld_func_lookup("__dyld_get_image_header", &dyld_get_image_header_fn); + _dyld_func_lookup("__dyld_NSLookupSymbolInImage", &NSLookupSymbolInImage_fn); + _dyld_func_lookup("__dyld_NSAddressOfSymbol", &NSAddressOfSymbol_fn); + + /* If any of these don't exist, that's an error. */ + if (! dyld_image_count_fn || ! dyld_get_image_name_fn + || ! dyld_get_image_header_fn || ! NSLookupSymbolInImage_fn + || ! NSAddressOfSymbol_fn) + return NULL; + + count = dyld_image_count_fn (); + for (i = 0; i < count; i++) + { + const char * path = dyld_get_image_name_fn (i); + const void * image; + const void * symbol; + + if (strcmp (path, "/usr/lib/libSystem.B.dylib") != 0) + continue; + image = dyld_get_image_header_fn (i); + if (! image) + return NULL; + /* '4' is NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR. */ + symbol = NSLookupSymbolInImage_fn (image, "_atexit", 4); + if (! symbol) + return NULL; + return NSAddressOfSymbol_fn (symbol); + } + return NULL; +} +#endif + +/* Create (if necessary), find, lock, fill in, and return our globals. + Return NULL on error, in which case the globals will not be locked. + The caller should call keymgr_set_and_unlock. */ +static struct keymgr_atexit_list * +get_globals (void) +{ + struct keymgr_atexit_list * r; + +#ifdef __ppc__ + /* 10.3.9 doesn't have _keymgr_get_and_lock_processwide_ptr_2 so the + PPC side can't use it. On 10.4 this just means the error gets + reported a little later when + _keymgr_set_and_unlock_processwide_ptr finds that the key was + never locked. */ + r = _keymgr_get_and_lock_processwide_ptr (KEYMGR_ATEXIT_LIST); +#else + void * rr; + if (_keymgr_get_and_lock_processwide_ptr_2 (KEYMGR_ATEXIT_LIST, &rr)) + return NULL; + r = rr; +#endif + + if (r == NULL) + { + r = calloc (sizeof (struct keymgr_atexit_list), 1); + if (! r) + return NULL; + } + + if (r->atexit_status == atexit_status_unknown) + { + void *handle; + + handle = dlopen ("/usr/lib/libSystem.B.dylib", RTLD_NOLOAD); + if (!handle) + { +#ifdef __ppc__ + r->atexit_status = atexit_status_missing; + r->atexit_f = find_atexit_10_3 (); + if (! r->atexit_f) + goto error; + if (r->atexit_f (our_atexit)) + goto error; +#else + goto error; +#endif + } + else + { + int chk_result; + + r->cxa_atexit_f = (cxa_atexit_p)dlsym (handle, "__cxa_atexit"); + r->cxa_finalize_f = (cxa_finalize_p)dlsym (handle, "__cxa_finalize"); + if (! r->cxa_atexit_f || ! r->cxa_finalize_f) + goto error; + + chk_result = check_cxa_atexit (r->cxa_atexit_f, r->cxa_finalize_f); + if (chk_result == -1) + goto error; + else if (chk_result == 0) + r->atexit_status = atexit_status_broken; + else + { + r->atexit_f = (atexit_p)dlsym (handle, "atexit"); + if (! r->atexit_f) + goto error; + r->atexit_status = atexit_status_working; + } + } + } + + return r; + + error: + _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, r); + return NULL; +} + +/* Add TO_ADD to ATEXIT_LIST. ATEXIT_LIST may be NULL but is + always the result of calling _keymgr_get_and_lock_processwide_ptr and + so KEYMGR_ATEXIT_LIST is known to be locked; this routine is responsible + for unlocking it. */ + +static int +add_routine (struct keymgr_atexit_list * g, + const struct one_atexit_routine * to_add) +{ + struct atexit_routine_list * s + = malloc (sizeof (struct atexit_routine_list)); + int result; + + if (!s) + { + _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); + return -1; + } + s->r = *to_add; + s->next = g->l; + g->l = s; + result = _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); + return CHECK_KEYMGR_ERROR (result) == 0 ? 0 : -1; +} + +/* This runs the routines in G->L up to STOP. */ +static struct keymgr_atexit_list * +run_routines (struct keymgr_atexit_list *g, + struct atexit_routine_list *stop) +{ + for (;;) + { + struct atexit_routine_list * cur = g->l; + if (! cur || cur == stop) + break; + g->l = cur->next; + _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); + + switch (cur->r.has_arg) { + case 0: case 2: case 4: + cur->r.callback.ac (); + break; + case 1: case 3: case 5: + cur->r.callback.cac (cur->r.arg); + break; + default: + /* Don't understand, so don't call it. */ + break; + } + free (cur); + + g = _keymgr_get_and_lock_processwide_ptr (KEYMGR_ATEXIT_LIST); + if (! g) + break; + } + return g; +} + +/* Call the routine described by ROUTINE_PARAM and then call any + routines added to KEYMGR_ATEXIT_LIST while that routine was + running, all with in_cxa_finalize set. */ + +static void +cxa_atexit_wrapper (void* routine_param) +{ + struct one_atexit_routine * routine = routine_param; + struct keymgr_atexit_list *g; + struct atexit_routine_list * base = NULL; + char prev_running = 0; + + g = _keymgr_get_and_lock_processwide_ptr (KEYMGR_ATEXIT_LIST); + if (g) + { + prev_running = g->running_routines; + g->running_routines = 1; + base = g->l; + _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); + } + + if (routine->has_arg) + routine->callback.cac (routine->arg); + else + routine->callback.ac (); + + if (g) + g = _keymgr_get_and_lock_processwide_ptr (KEYMGR_ATEXIT_LIST); + if (g) + g = run_routines (g, base); + if (g) + { + g->running_routines = prev_running; + _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); + } +} + +#ifdef __ppc__ +/* This code is used while running on 10.3.9, when __cxa_atexit doesn't + exist in the system library. 10.3.9 only supported regular PowerPC, + so this code isn't necessary on x86 or ppc64. */ + +/* This routine is called from the system atexit(); it runs everything + registered on the KEYMGR_ATEXIT_LIST. */ + +static void +our_atexit (void) +{ + struct keymgr_atexit_list *g; + char prev_running; + + g = _keymgr_get_and_lock_processwide_ptr (KEYMGR_ATEXIT_LIST); + if (! g || g->version != 0 || g->atexit_status != atexit_status_missing) + return; + + prev_running = g->running_routines; + g->running_routines = 1; + g = run_routines (g, NULL); + if (! g) + return; + g->running_routines = prev_running; + _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); +} +#endif + +/* This is our wrapper around atexit and __cxa_atexit. It will return + nonzero if an error occurs, and otherwise: + - if in_cxa_finalize is set, or running on 10.3.9, add R to + KEYMGR_ATEXIT_LIST; or + - call the system __cxa_atexit to add cxa_atexit_wrapper with an argument + that indicates how cxa_atexit_wrapper should call R. */ + +static int +atexit_common (const struct one_atexit_routine *r, const void *dso) +{ + struct keymgr_atexit_list *g = get_globals (); + + if (! g) + return -1; + + if (g->running_routines || g->atexit_status == atexit_status_missing) + return add_routine (g, r); + + if (g->atexit_status >= atexit_status_working) + { + int result; + if (r->has_arg) + { + cxa_atexit_p cxa_atexit = g->cxa_atexit_f; + result = _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, + g); + if (CHECK_KEYMGR_ERROR (result)) + return -1; + return cxa_atexit (r->callback.cac, r->arg, dso); + } + else + { + atexit_p atexit_f = g->atexit_f; + result = _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, + g); + if (CHECK_KEYMGR_ERROR (result)) + return -1; + return atexit_f (r->callback.ac); + } + } + else + { + cxa_atexit_p cxa_atexit = g->cxa_atexit_f; + struct one_atexit_routine *alloced; + int result; + + result = _keymgr_set_and_unlock_processwide_ptr (KEYMGR_ATEXIT_LIST, g); + if (CHECK_KEYMGR_ERROR (result)) + return -1; + + alloced = malloc (sizeof (struct one_atexit_routine)); + if (! alloced) + return -1; + *alloced = *r; + return cxa_atexit (cxa_atexit_wrapper, alloced, dso); + } +} + +/* These are the actual replacement routines; they just funnel into + atexit_common. */ + +int __cxa_atexit (cxa_atexit_callback func, void* arg, + const void* dso) __attribute__((visibility("hidden"))); + +int +__cxa_atexit (cxa_atexit_callback func, void* arg, const void* dso) +{ + struct one_atexit_routine r; + r.callback.cac = func; + r.has_arg = 1; + r.arg = arg; + return atexit_common (&r, dso); +} + +int atexit (atexit_callback func) __attribute__((visibility("hidden"))); + +/* Use __dso_handle to allow even bundles that call atexit() to be unloaded + on 10.4. */ +extern void __dso_handle; + +int +atexit (atexit_callback func) +{ + struct one_atexit_routine r; + r.callback.ac = func; + r.has_arg = 0; + return atexit_common (&r, &__dso_handle); +} + +#endif /* __PIC__ */ |