1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/kernelhwsrv/kernel/eka/compsupp/aehabi/cppsemantics.cpp Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,1311 @@
1.4 +/* The C++ exceptions runtime support
1.5 + *
1.6 + * Copyright 2002-2003 ARM Limited.
1.7 + */
1.8 +/*
1.9 + Licence
1.10 +
1.11 + 1. Subject to the provisions of clause 2, ARM hereby grants to LICENSEE a
1.12 + perpetual, non-exclusive, nontransferable, royalty free, worldwide licence
1.13 + to use this Example Implementation of Exception Handling solely for the
1.14 + purpose of developing, having developed, manufacturing, having
1.15 + manufactured, offering to sell, selling, supplying or otherwise
1.16 + distributing products which comply with the Exception Handling ABI for the
1.17 + ARM Architecture specification. All other rights are reserved to ARM or its
1.18 + licensors.
1.19 +
1.20 + 2. THIS EXAMPLE IMPLEMENTATION OF EXCEPTION HANDLING IS PROVIDED "AS IS"
1.21 + WITH NO WARRANTIES EXPRESS, IMPLIED OR STATUTORY, INCLUDING BUT NOT LIMITED
1.22 + TO ANY WARRANTY OF SATISFACTORY QUALITY, MERCHANTABILITY, NONINFRINGEMENT
1.23 + OR FITNESS FOR A PARTICULAR PURPOSE.
1.24 +*/
1.25 +/*
1.26 + * RCS $Revision: 1.29.2.1 $
1.27 + * Checkin $Date: 2004/01/20 15:11:16 $
1.28 + * Revising $Author: achapman $
1.29 + */
1.30 +
1.31 +/* This source file is compiled automatically by ARM's make system into
1.32 + * multiple object files. The source regions constituting object file
1.33 + * xxx.o are delimited by ifdef xxx_c / endif directives.
1.34 + *
1.35 + * The source regions currently marked are:
1.36 + * arm_exceptions_globs_c
1.37 + * arm_exceptions_mem_c
1.38 + * arm_exceptions_uncaught_c
1.39 + * arm_exceptions_terminate_c
1.40 + * arm_exceptions_setterminate_c
1.41 + * arm_exceptions_unexpected_c
1.42 + * arm_exceptions_setunexpected_c
1.43 + * arm_exceptions_support_c
1.44 + * arm_exceptions_callterm_c
1.45 + * arm_exceptions_callunex_c
1.46 + * arm_exceptions_currenttype_c
1.47 + * arm_exceptions_alloc_c
1.48 + * arm_exceptions_free_c
1.49 + * arm_exceptions_throw_c
1.50 + * arm_exceptions_rethrow_c
1.51 + * arm_exceptions_foreign_c
1.52 + * arm_exceptions_cleanup_c
1.53 + * arm_exceptions_begincatch_c
1.54 + * arm_exceptions_endcatch_c
1.55 + * arm_exceptions_bad_typeid_c
1.56 + * arm_exceptions_bad_cast_c
1.57 + */
1.58 +
1.59 +#include <string.h>
1.60 +#include <typeinfo>
1.61 +#include <exception>
1.62 +#include <new>
1.63 +// Environment:
1.64 +#include "unwind_env.h"
1.65 +// Language-independent unwinder declarations:
1.66 +#include "unwinder.h"
1.67 +
1.68 +/* By default, none of these routines are unwindable: */
1.69 +#pragma noexceptions_unwind
1.70 +
1.71 +/* For brevity: */
1.72 +
1.73 +typedef _Unwind_Control_Block UCB;
1.74 +
1.75 +using std::terminate_handler;
1.76 +using std::unexpected_handler;
1.77 +using std::terminate;
1.78 +using std::unexpected;
1.79 +using std::type_info;
1.80 +
1.81 +/* Redeclare these interface routines as weak, so using them does not
1.82 + * pull in the unwind library. We only want the unwind library if
1.83 + * someone throws (or raises an exception from some other language).
1.84 + */
1.85 +WEAKDECL NORETURNDECL void _Unwind_Resume(UCB *);
1.86 +WEAKDECL void _Unwind_Complete(UCB *);
1.87 +
1.88 +/* Diagnostics:
1.89 + * Define DEBUG to get extra interfaces which assist debugging this functionality.
1.90 + * Define PRINTED_DIAGNOSTICS for printed diagnostics.
1.91 + */
1.92 +#ifdef DEBUG
1.93 +#define PRINTED_DIAGNOSTICS
1.94 +#endif
1.95 +
1.96 +#ifdef PRINTED_DIAGNOSTICS
1.97 +extern "C" int printf(const char *, ...);
1.98 +#endif
1.99 +
1.100 +/* --------- "Exceptions_class" string for our implementation: --------- */
1.101 +
1.102 +#define EXCEPTIONS_CLASS_SIZE 8
1.103 +#define ARMCPP_EXCEPTIONS_CLASS "ARM\0C++\0"
1.104 +
1.105 +
1.106 +/* --------- Exception control object: --------- */
1.107 +
1.108 +// Type __cxa_exception is the combined C++ housekeeping (LEO) and UCB.
1.109 +// It will be followed by the user exception object, hence must ensure
1.110 +// the latter is aligned on an 8 byte boundary.
1.111 +
1.112 +struct __cxa_exception {
1.113 + const type_info *exceptionType; // RTTI object describing the type of the exception
1.114 + void *(*exceptionDestructor)(void *); // Destructor for the exception object (may be NULL)
1.115 + unexpected_handler unexpectedHandler; // Handler in force after evaluating throw expr
1.116 + terminate_handler terminateHandler; // Handler in force after evaluating throw expr
1.117 + __cxa_exception *nextCaughtException; // Chain of "currently caught" c++ exception objects
1.118 + uint32_t handlerCount; // Count of how many handlers this EO is "caught" in
1.119 + __cxa_exception *nextPropagatingException; // Chain of objects saved over cleanup
1.120 + uint32_t propagationCount; // Count of live propagations (throws) of this EO
1.121 + UCB ucb; // Forces alignment of next item to 8-byte boundary
1.122 +};
1.123 +
1.124 +
1.125 +/* --------- Control "globals": --------- */
1.126 +
1.127 +// We do this by putting all the thread-specific "globals" into a single
1.128 +// area of store, which we allocate space for dynamically.
1.129 +// We don't define a constructor for this; see comments with __cxa_get_globals.
1.130 +
1.131 +typedef void (*handler)(void);
1.132 +
1.133 +struct __cxa_eh_globals {
1.134 + uint32_t uncaughtExceptions; // counter
1.135 + unexpected_handler unexpectedHandler; // per-thread handler
1.136 + terminate_handler terminateHandler; // per-thread handler
1.137 + bool implementation_ever_called_terminate; // true if it ever did
1.138 + handler call_hook; // transient field to tell terminate/unexpected which hook to call
1.139 + __cxa_exception *caughtExceptions; // chain of "caught" exceptions
1.140 + __cxa_exception *propagatingExceptions; // chain of "propagating" (in cleanup) exceptions
1.141 + void *emergency_buffer; // emergency buffer for when rest of heap full
1.142 +};
1.143 +
1.144 +
1.145 +/* ---------- Entry points: ---------- */
1.146 +
1.147 +/* There is a little type-delicacy required here as __cxa_throw takes a
1.148 + * function pointer. Setting aside the problem of not being able to form
1.149 + * a pointer to a destructor in C++, if we simply say extern "C" here
1.150 + * then the function pointer will also have C linkage and will be a
1.151 + * pointer to a C function. This causes problems when __cxa_throw is
1.152 + * defined (unless we repeat the extern "C" at the definition site) because
1.153 + * the fnptr in the definition gets C++ linkage, hence that __cxa_throw has
1.154 + * a different signature to the declared one, and so the function we wanted
1.155 + * doesn't get defined at all.
1.156 + * Maybe it should just take a void * but this seems more honest.
1.157 + */
1.158 +
1.159 +typedef void *(*cppdtorptr)(void *);
1.160 +
1.161 +extern "C" {
1.162 +
1.163 + // Protocol routines called directly from application code
1.164 +
1.165 + void *__cxa_allocate_exception(size_t size);
1.166 + void __cxa_free_exception(void *);
1.167 + WEAKDECL void __cxa_throw(void *, const type_info *, cppdtorptr);
1.168 + void __cxa_rethrow(void);
1.169 + void *__cxa_begin_catch(UCB *);
1.170 + void __cxa_end_catch(void);
1.171 + void __cxa_end_cleanup(void);
1.172 + const type_info *__cxa_current_exception_type(void);
1.173 +
1.174 + // Protocol routines usually called only by the personality routine(s).
1.175 +
1.176 + void __cxa_call_terminate(UCB *);
1.177 + void __cxa_call_unexpected(UCB *);
1.178 + bool __cxa_begin_cleanup(UCB *);
1.179 + bool __cxa_type_match(UCB *, const std::type_info *, void **);
1.180 +
1.181 + // Auxilliary routines
1.182 +
1.183 + __cxa_eh_globals *__cxa_get_globals(void);
1.184 + void __cxa_bad_typeid(void);
1.185 + void __cxa_bad_cast(void);
1.186 +
1.187 + // Emergency memory buffer management routines
1.188 +
1.189 + void *__ARM_exceptions_buffer_init(void);
1.190 + void *__ARM_exceptions_buffer_allocate(void *, size_t);
1.191 + void *__ARM_exceptions_buffer_free(void *, void *);
1.192 +}
1.193 +
1.194 +
1.195 +// Support routines
1.196 +
1.197 +#define NAMES __ARM
1.198 +namespace NAMES {
1.199 + void default_unexpected_handler(void);
1.200 + void call_terminate_handler(UCB *);
1.201 + void eh_catch_semantics(UCB *);
1.202 + bool is_foreign_exception(UCB *);
1.203 + bool same_exceptions_class(const void *, const void *);
1.204 + __cxa_exception *get_foreign_intermediary(__cxa_exception *, UCB *);
1.205 +}
1.206 +
1.207 +// Macro: convert ucb pointer to __cxa_exception pointer
1.208 +
1.209 +#define ucbp_to_ep(UCB_P) ((__cxa_exception *)((char *)(UCB_P) - offsetof(__cxa_exception, ucb)))
1.210 +
1.211 +
1.212 +#ifdef arm_exceptions_globs_c
1.213 +
1.214 +/* --------- Allocating and retrieving "globals": --------- */
1.215 +
1.216 +// The exception-handling globals should be allocated per-thread.
1.217 +// This is done here assuming the existance of a zero-initialised void*
1.218 +// pointer location obtainable by the macro EH_GLOBALS.
1.219 +
1.220 +// Default terminate handler:
1.221 +
1.222 +static void __default_terminate_handler(void) {
1.223 + abort();
1.224 +}
1.225 +
1.226 +// If std::unexpected() is in the image, include a default handler for it:
1.227 +namespace NAMES { WEAKDECL void default_unexpected_handler(void); }
1.228 +
1.229 +// If this symbol is present, allocate an emergency buffer.
1.230 +// As we aren't allowed static data, make it a function
1.231 +extern "C" WEAKDECL void __ARM_exceptions_buffer_required(void);
1.232 +
1.233 +
1.234 +// __cxa_eh_globals returns the per-thread memory. There are several complications,
1.235 +// all of which relate to not touching the exceptions system while trying to
1.236 +// initialise it:
1.237 +// 1) We can't obtain memory by calling new or nothrow new as both of these use
1.238 +// exceptions internally, so we must use malloc
1.239 +// 2) We choose not to initialise the memory via placement new and a constructor,
1.240 +// since placement new is declared with an empty function exception specification,
1.241 +// which causes more of the exceptions system to always be pulled in.
1.242 +// 3) We can't call terminate, as terminate looks in the memory we are trying to
1.243 +// allocate.
1.244 +
1.245 +__cxa_eh_globals *__cxa_get_globals(void)
1.246 +{
1.247 + __cxa_eh_globals *this_thread_globals = (__cxa_eh_globals *)(EH_GLOBALS);
1.248 + if (this_thread_globals == NULL) {
1.249 +
1.250 + // First call
1.251 + // Obtain some memory: this is thread-safe provided malloc is.
1.252 + this_thread_globals = (__cxa_eh_globals *)malloc(sizeof(__cxa_eh_globals));
1.253 + if (this_thread_globals == NULL) abort(); // NOT terminate(), which calls this fn
1.254 +
1.255 + // Save the pointer in the specially-provided location
1.256 + EH_GLOBALS = this_thread_globals;
1.257 +
1.258 + // Finally initialise the memory by hand
1.259 + this_thread_globals->uncaughtExceptions = 0;
1.260 + this_thread_globals->unexpectedHandler = NAMES::default_unexpected_handler;
1.261 + this_thread_globals->terminateHandler = __default_terminate_handler;
1.262 + this_thread_globals->implementation_ever_called_terminate = false;
1.263 + this_thread_globals->call_hook = NULL;
1.264 + this_thread_globals->caughtExceptions = NULL;
1.265 + this_thread_globals->propagatingExceptions = NULL;
1.266 + if (&__ARM_exceptions_buffer_required == NULL)
1.267 + this_thread_globals->emergency_buffer = NULL;
1.268 + else
1.269 + this_thread_globals->emergency_buffer = __ARM_exceptions_buffer_init();
1.270 + }
1.271 +
1.272 + return this_thread_globals;
1.273 +}
1.274 +
1.275 +
1.276 +#endif /* arm_exceptions_globs_c */
1.277 +#ifdef arm_exceptions_mem_c
1.278 +
1.279 +/* --------- Emergency memory: --------- */
1.280 +
1.281 +// It is possible to reserve memory for throwing bad_alloc when the heap
1.282 +// is otherwise full. The ARM implementation provides hooks to do this.
1.283 +// The default implementation reserves just enough space for a bad_alloc
1.284 +// object, so if memory is later exhausted bad_alloc can still be thrown.
1.285 +// Note there is no guarantee or requirement that the exception being
1.286 +// thrown is actually bad_alloc.
1.287 +
1.288 +// A usage flag and enough space for a bad_alloc exception control object
1.289 +
1.290 +struct emergency_eco {
1.291 + __cxa_exception ep;
1.292 + std::bad_alloc b;
1.293 +};
1.294 +
1.295 +struct emergency_buffer {
1.296 + bool inuse;
1.297 + struct emergency_eco eco;
1.298 +};
1.299 +
1.300 +// Initialiser
1.301 +void* __ARM_exceptions_buffer_init(void)
1.302 +{
1.303 + emergency_buffer *buffer = (emergency_buffer *)malloc(sizeof(emergency_buffer));
1.304 + if (buffer == NULL) return NULL;
1.305 + buffer->inuse = false;
1.306 + return buffer;
1.307 +}
1.308 +
1.309 +// Allocator
1.310 +void *__ARM_exceptions_buffer_allocate(void *buffer, size_t size)
1.311 +{
1.312 + emergency_buffer *b = (emergency_buffer *)buffer;
1.313 + if (size > sizeof(emergency_eco) || b == NULL || b->inuse) return NULL;
1.314 + b->inuse = true;
1.315 + return &b->eco;
1.316 +}
1.317 +
1.318 +// Deallocator: Must return non-NULL if and only if it recognises
1.319 +// and releases the supplied object
1.320 +void *__ARM_exceptions_buffer_free(void *buffer, void *addr)
1.321 +{
1.322 + emergency_buffer *b = (emergency_buffer *)buffer;
1.323 + if (b == NULL || addr != &b->eco) return NULL;
1.324 + b->inuse = false;
1.325 + return b;
1.326 +}
1.327 +
1.328 +
1.329 +#endif /* arm_exceptions_mem_c */
1.330 +#ifdef arm_exceptions_uncaught_c
1.331 +
1.332 +/* ---- uncaught_exception() ---- */
1.333 +
1.334 +/* The EDG (and I think our) interpretation is that if the implementation
1.335 + * ever called terminate(), uncaught_exception() should return true.
1.336 + */
1.337 +
1.338 +bool std::uncaught_exception(void)
1.339 +{
1.340 + __cxa_eh_globals *g = __cxa_get_globals();
1.341 + return g->implementation_ever_called_terminate || g->uncaughtExceptions;
1.342 +}
1.343 +
1.344 +
1.345 +#endif /* arm_exceptions_uncaught_c */
1.346 +#ifdef arm_exceptions_terminate_c
1.347 +
1.348 +/* ---- terminate() etc ---- */
1.349 +
1.350 +/* The behaviour of terminate() must differ between calls by the
1.351 + * implementation and calls by the application. This is achieved by having the
1.352 + * implementation set call_hook immediately before the call to terminate().
1.353 + * The hook called by terminate() should terminate the program without
1.354 + * returning to the caller. There is no requirement for terminate() itself to
1.355 + * intercept throws.
1.356 + */
1.357 +
1.358 +void std::terminate(void)
1.359 +{
1.360 + __cxa_eh_globals *g = __cxa_get_globals();
1.361 +
1.362 + if (g->call_hook != NULL) {
1.363 + // Clear then call hook fn we were passed
1.364 + handler call_hook = g->call_hook;
1.365 + g->call_hook = NULL;
1.366 + call_hook();
1.367 + } else {
1.368 + // Call global hook fn
1.369 + g->terminateHandler();
1.370 + }
1.371 + // If hook fn returns:
1.372 + abort();
1.373 +}
1.374 +
1.375 +
1.376 +#endif /* arm_exceptions_terminate_c */
1.377 +#ifdef arm_exceptions_setterminate_c
1.378 +
1.379 +terminate_handler std::set_terminate(terminate_handler h) throw()
1.380 +{
1.381 + __cxa_eh_globals *g = __cxa_get_globals();
1.382 + terminate_handler old = g->terminateHandler;
1.383 + g->terminateHandler = h;
1.384 + return old;
1.385 +}
1.386 +
1.387 +
1.388 +#endif /* arm_exceptions_setterminate_c */
1.389 +#ifdef arm_exceptions_unexpected_c
1.390 +
1.391 +/* ---- unexpected() etc ---- */
1.392 +/* Comments as per terminate() */
1.393 +
1.394 +void NAMES::default_unexpected_handler(void) {
1.395 + terminate();
1.396 +}
1.397 +
1.398 +#pragma exceptions_unwind
1.399 +
1.400 +void std::unexpected(void)
1.401 +{
1.402 + __cxa_eh_globals *g = __cxa_get_globals();
1.403 +
1.404 + if (g->call_hook != NULL) {
1.405 + // Clear then call hook fn we were passed
1.406 + handler call_hook = g->call_hook;
1.407 + g->call_hook = NULL;
1.408 + call_hook();
1.409 + } else {
1.410 + // Call global hook fn
1.411 + g->unexpectedHandler();
1.412 + }
1.413 +
1.414 + // If hook fn returns:
1.415 + abort();
1.416 +}
1.417 +
1.418 +
1.419 +#endif /* arm_exceptions_unexpected_c */
1.420 +#ifdef arm_exceptions_setunexpected_c
1.421 +
1.422 +unexpected_handler std::set_unexpected(unexpected_handler h) throw()
1.423 +{
1.424 + __cxa_eh_globals *g = __cxa_get_globals();
1.425 + unexpected_handler old = g->unexpectedHandler;
1.426 + g->unexpectedHandler = h;
1.427 + return old;
1.428 +}
1.429 +
1.430 +
1.431 +#endif /* arm_exceptions_setunexpected_c */
1.432 +#ifdef arm_exceptions_support_c
1.433 +
1.434 +/* ---------- Helper functions: ---------- */
1.435 +
1.436 +/* Two routines to determine whether two exceptions objects share a layout.
1.437 + * This is determined by checking whether the UCB exception_class members
1.438 + * are identical.
1.439 + * In principle we could use memcmp to perform this check (the code is
1.440 + * given below) but the check is quite frequent and so that is costly.
1.441 + * Therefore for efficiency we make use of the fact that the UCB is
1.442 + * word aligned, that the exception_class member is consequently
1.443 + * word aligned within it, and that we know the size of the member.
1.444 + * We take care elsewhere to only ever call the routines with pointers
1.445 + * to word-aligned addresses.
1.446 + */
1.447 +
1.448 +#if 0
1.449 +
1.450 +// Straightforward versions
1.451 +
1.452 +bool NAMES::same_exceptions_class(const void *ec1, const void *ec2)
1.453 +{
1.454 + return memcmp(ec1, ec2, EXCEPTIONS_CLASS_SIZE) == 0; // identical
1.455 +}
1.456 +
1.457 +// One of our exception objects, or not?
1.458 +
1.459 +bool NAMES::is_foreign_exception(UCB *ucbp)
1.460 +{
1.461 + return !NAMES::same_exceptions_class(&ucbp->exception_class, ARMCPP_EXCEPTIONS_CLASS);
1.462 +}
1.463 +
1.464 +#else
1.465 +
1.466 +// Faster versions
1.467 +
1.468 +bool NAMES::same_exceptions_class(const void *ec1, const void *ec2)
1.469 +{
1.470 + uint32_t *ip1 = (uint32_t *)ec1;
1.471 + uint32_t *ip2 = (uint32_t *)ec2;
1.472 + return ip1[0] == ip2[0] && ip1[1] == ip2[1];
1.473 +}
1.474 +
1.475 +// One of our exception objects, or not?
1.476 +
1.477 +bool NAMES::is_foreign_exception(UCB *ucbp)
1.478 +{
1.479 + // Need a word-aligned copy of the string
1.480 + static const union {
1.481 + const char s[EXCEPTIONS_CLASS_SIZE+1]; int dummy;
1.482 + } is_foreign_exception_static = {ARMCPP_EXCEPTIONS_CLASS};
1.483 + return !NAMES::same_exceptions_class(&ucbp->exception_class, &is_foreign_exception_static.s);
1.484 +}
1.485 +
1.486 +#endif
1.487 +
1.488 +
1.489 +#endif /* arm_exceptions_support_c */
1.490 +#ifdef arm_exceptions_callterm_c
1.491 +
1.492 +/* When the implementation wants to call terminate(), do the following:
1.493 + * Mark the object as "caught" so it can be rethrown.
1.494 + * Set the hook function for terminate() to call;
1.495 + * Mark the fact that terminate() has been called by the implementation;
1.496 + * We have to be careful - the implementation might encounter an error while
1.497 + * unwinding a foreign exception, and also it is possible this might be
1.498 + * called after failing to obtain a ucb.
1.499 + */
1.500 +
1.501 +void NAMES::call_terminate_handler(UCB *ucbp)
1.502 +{
1.503 + __cxa_eh_globals *g = __cxa_get_globals();
1.504 +
1.505 + if (ucbp == NULL) {
1.506 + // Call global hook
1.507 + g->call_hook = g->terminateHandler;
1.508 + } else {
1.509 + // Extract the hook to call
1.510 + if (NAMES::is_foreign_exception(ucbp)) {
1.511 + // Someone else's
1.512 + g->call_hook = g->terminateHandler; // best we can do under the circumstances
1.513 + } else {
1.514 + // One of ours
1.515 + __cxa_exception *ep = ucbp_to_ep(ucbp);
1.516 + g->call_hook = ep->terminateHandler; // the one in force at the point of throw
1.517 + }
1.518 + }
1.519 +
1.520 + g->implementation_ever_called_terminate = true;
1.521 + terminate();
1.522 + // never returns
1.523 +}
1.524 +
1.525 +
1.526 +void __cxa_call_terminate(UCB *ucbp)
1.527 +{
1.528 + if (ucbp != NULL) // Record entry to (implicit) handler
1.529 + __cxa_begin_catch(ucbp);
1.530 +
1.531 + NAMES::call_terminate_handler(ucbp);
1.532 + // never returns
1.533 +}
1.534 +
1.535 +
1.536 +#endif /* arm_exceptions_callterm_c */
1.537 +#ifdef arm_exceptions_callunex_c
1.538 +
1.539 +/* When the implementation wants to call unexpected(), do the following:
1.540 + * Mark the object as "caught" so it can be rethrown.
1.541 + * Set the hook function for unexpected() to call;
1.542 + * Call unexpected and trap any throw to make sure it is acceptable.
1.543 + * We have to be careful - the implementation might encounter an error while
1.544 + * unwinding a foreign exception.
1.545 + */
1.546 +
1.547 +#pragma exceptions_unwind
1.548 +
1.549 +void __cxa_call_unexpected(UCB *ucbp)
1.550 +{
1.551 +
1.552 + // Extract data we will need from the barrier cache before
1.553 + // anyone has a chance to overwrite it
1.554 +
1.555 + uint32_t rtti_count = ucbp->barrier_cache.bitpattern[1];
1.556 + uint32_t base = ucbp->barrier_cache.bitpattern[2];
1.557 + uint32_t stride = ucbp->barrier_cache.bitpattern[3];
1.558 + uint32_t rtti_offset_array_addr = ucbp->barrier_cache.bitpattern[4];
1.559 +
1.560 + // Also get the globals here and the eop
1.561 +
1.562 + __cxa_eh_globals *g = __cxa_get_globals();
1.563 + __cxa_exception *ep = ucbp_to_ep(ucbp);
1.564 +
1.565 +#ifdef ARM_EXCEPTIONS_ENABLED
1.566 + try {
1.567 +#endif
1.568 +
1.569 + // Record entry to (implicit) handler
1.570 +
1.571 + __cxa_begin_catch(ucbp);
1.572 +
1.573 + // Now extract the hook to call
1.574 +
1.575 + if (NAMES::is_foreign_exception(ucbp)) {
1.576 + // Someone else's
1.577 + g->call_hook = g->unexpectedHandler; // best we can do under the circumstances
1.578 + } else {
1.579 + // One of ours
1.580 + g->call_hook = ep->unexpectedHandler; // the one in force at the point of throw
1.581 + }
1.582 + unexpected(); // never returns normally, but might throw something
1.583 +
1.584 +#ifdef ARM_EXCEPTIONS_ENABLED
1.585 + } catch (...) {
1.586 +
1.587 + // Unexpected() threw. This requires some delicacy.
1.588 + // There are 2 possibilities:
1.589 + // i) rethrow of the same object
1.590 + // ii) throw of a new object
1.591 + // Unexpected() is an implicit handler, and we manually called
1.592 + // __cxa_begin_catch on the ingoing object. We need to call
1.593 + // __cxa_end_catch on that object and, if the object is no longer
1.594 + // being handled (possible in case ii), this will cause its destruction.
1.595 + // The wrinkle is that in case ii the object is not on top of the catch
1.596 + // stack because we just caught something else.
1.597 +
1.598 + // Get hold of what was thrown (which we just caught).
1.599 +
1.600 + __cxa_exception *epnew = g->caughtExceptions;
1.601 +
1.602 + // Call __cxa_end_catch on the original object, taking care with the catch chain
1.603 +
1.604 + if (epnew == ep) {
1.605 + // rethrow - easy & safe - object is at top of chain and handlercount > 1
1.606 + __cxa_end_catch();
1.607 + } else {
1.608 + // not rethrow - unchain the top (new) object, clean up the next one,
1.609 + // and put the top object back
1.610 +
1.611 + // unchain
1.612 + g->caughtExceptions = epnew->nextCaughtException;
1.613 + // assert g->caughtExceptions == ep now
1.614 + // Decrement its handlercount (this might call a dtor if the count goes to 0,
1.615 + // and the dtor might throw - if it does, just give up)
1.616 + try {
1.617 + __cxa_end_catch();
1.618 + } catch(...) {
1.619 + terminate();
1.620 + }
1.621 + // Chain back in
1.622 + epnew->nextCaughtException = g->caughtExceptions;
1.623 + g->caughtExceptions = epnew;
1.624 + }
1.625 +
1.626 + // See whether what was thrown is permitted, and in passing
1.627 + // see if std::bad_exception is permitted
1.628 +
1.629 + bool bad_exception_permitted = false;
1.630 + uint32_t i;
1.631 + for (i = 0; i < rtti_count; i++) {
1.632 + void *matched_object;
1.633 + const type_info *fnspec = (const type_info *)(*(uint32_t *)rtti_offset_array_addr + base);
1.634 + if (__cxa_type_match(&(epnew->ucb), fnspec, &matched_object)) {
1.635 +#ifdef PRINTED_DIAGNOSTICS
1.636 + printf("__cxa_call_unexpected: fnspec matched\n");
1.637 +#endif
1.638 + throw; // got a match - propagate it
1.639 + }
1.640 + if (&typeid(std::bad_exception) == fnspec)
1.641 + bad_exception_permitted = true;
1.642 + rtti_offset_array_addr += stride;
1.643 + }
1.644 +
1.645 + // There was no match...
1.646 + if (bad_exception_permitted) throw std::bad_exception(); // transmute
1.647 +
1.648 + // Otherwise call epnew's terminate handler
1.649 + NAMES::call_terminate_handler(&epnew->ucb);
1.650 + }
1.651 +#endif
1.652 +}
1.653 +
1.654 +
1.655 +#endif /* arm_exceptions_callunex_c */
1.656 +#ifdef arm_exceptions_currenttype_c
1.657 +
1.658 +/* Yield the type of the currently handled exception, or null if none or the
1.659 + * object is foreign.
1.660 + */
1.661 +
1.662 +const type_info *__cxa_current_exception_type(void)
1.663 +{
1.664 + __cxa_eh_globals *g = __cxa_get_globals();
1.665 + __cxa_exception *ep = g->caughtExceptions;
1.666 + if (ep == NULL || NAMES::is_foreign_exception(&ep->ucb)) return NULL;
1.667 + return ep->exceptionType;
1.668 +}
1.669 +
1.670 +
1.671 +#endif /* arm_exceptions_currenttype_c */
1.672 +#ifdef arm_exceptions_alloc_c
1.673 +
1.674 +/* Allocate store for controlling an exception propagation */
1.675 +
1.676 +void *__cxa_allocate_exception(size_t size)
1.677 +{
1.678 + __cxa_eh_globals *g = __cxa_get_globals();
1.679 +
1.680 + // Allocate store for a __cxa_exception header and the EO.
1.681 + // Allocated store should be thread-safe and persistent, and must do
1.682 + // something sensible if the allocation fails
1.683 +
1.684 + size_t total_size = size + sizeof(__cxa_exception);
1.685 + __cxa_exception *ep = (__cxa_exception *)malloc(total_size);
1.686 + if (ep == NULL) {
1.687 + // Try the emergency memory pool
1.688 + ep = (__cxa_exception *)__ARM_exceptions_buffer_allocate(g->emergency_buffer, total_size);
1.689 + if (ep == NULL) NAMES::call_terminate_handler(NULL);
1.690 + }
1.691 +
1.692 + UCB *ucbp = &ep->ucb;
1.693 +
1.694 + // Initialise the UCB
1.695 +
1.696 + memcpy(ucbp->exception_class, ARMCPP_EXCEPTIONS_CLASS, EXCEPTIONS_CLASS_SIZE);
1.697 + ucbp->exception_cleanup = NULL; /* initialise properly before throwing */
1.698 + ucbp->unwinder_cache.reserved1 = 0; /* required to do this */
1.699 +
1.700 + // Initialise parts of the LEO, in case copy-construction of the EO results
1.701 + // in a need to call terminate (via __cxa_call_terminate)
1.702 +
1.703 + ep->handlerCount = 0; // Not in any handlers
1.704 + ep->nextCaughtException = NULL; // Not in any handlers
1.705 + ep->nextPropagatingException = NULL; // Not saved over cleanup
1.706 + ep->propagationCount = 0; // Not propagating
1.707 + ep->terminateHandler = g->terminateHandler; // Cache current terminate handler
1.708 + ep->unexpectedHandler = g->unexpectedHandler; // Cache current unexpected handler
1.709 +
1.710 + // Return pointer to the EO
1.711 +
1.712 + return ep + 1;
1.713 +}
1.714 +
1.715 +
1.716 +#endif /* arm_exceptions_alloc_c */
1.717 +#ifdef arm_exceptions_free_c
1.718 +
1.719 +/* Free store allocated by __cxa_allocate_exception */
1.720 +
1.721 +void __cxa_free_exception(void *eop)
1.722 +{
1.723 + __cxa_eh_globals *g = __cxa_get_globals();
1.724 + char *ep = (char *)eop - sizeof(__cxa_exception);
1.725 + if (__ARM_exceptions_buffer_free(g->emergency_buffer, ep)) return;
1.726 + free(ep);
1.727 +}
1.728 +
1.729 +
1.730 +#endif /* arm_exceptions_free_c */
1.731 +#ifdef arm_exceptions_throw_c
1.732 +
1.733 +/* This routine is called when a foreign runtime catches one of our exception
1.734 + * objects and then exits its catch by a means other than rethrow.
1.735 + * We should clean it up as if we had caught it ourselves.
1.736 + */
1.737 +
1.738 +static void external_exception_termination(_Unwind_Reason_Code c, UCB *ucbp)
1.739 +{
1.740 + NAMES::eh_catch_semantics(ucbp);
1.741 + __cxa_end_catch();
1.742 +}
1.743 +
1.744 +
1.745 +/* Initiate a throw */
1.746 +
1.747 +#pragma push
1.748 +#pragma exceptions_unwind
1.749 +
1.750 +void __cxa_throw(void *eop, const type_info *t, cppdtorptr d)
1.751 +{
1.752 + __cxa_exception *ep = (__cxa_exception *)((char *)eop - sizeof(__cxa_exception));
1.753 + UCB *ucbp = &ep->ucb;
1.754 +
1.755 + // Initialise the remaining LEO and UCB fields not done by __cxa_allocate_exception
1.756 +
1.757 + ucbp->exception_cleanup = external_exception_termination;
1.758 + ep->exceptionType = t;
1.759 + ep->exceptionDestructor = d;
1.760 + ep->propagationCount = 1; // Propagating by 1 throw
1.761 +
1.762 + // Increment the uncaught C++ exceptions count
1.763 +
1.764 + __cxa_eh_globals *g = __cxa_get_globals();
1.765 + g->uncaughtExceptions++;
1.766 +
1.767 + // Tell debugger what's happening
1.768 +
1.769 + DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_STARTING, t);
1.770 +
1.771 + // Initiate unwinding - if we get control back, call C++ routine terminate()
1.772 +
1.773 + _Unwind_RaiseException(ucbp);
1.774 +
1.775 +#ifdef PRINTED_DIAGNOSTICS
1.776 + printf("__cxa_throw: throw failed\n");
1.777 +#endif
1.778 +
1.779 + __cxa_call_terminate(ucbp);
1.780 +}
1.781 +
1.782 +#pragma pop
1.783 +
1.784 +/* ----- Type matching: ----- */
1.785 +
1.786 +/* This is located here so that (in ARM's implementation) it is only retained in
1.787 + * an image if the application itself throws.
1.788 + */
1.789 +
1.790 +/* Type matching functions.
1.791 + * C++ DR126 says the matching rules for fnspecs are intended to be the same as
1.792 + * those for catch:
1.793 + * "A function is said to allow an exception of type E if its exception-specification
1.794 + * contains a type T for which a handler of type T would be a match (15.3 except.handle)
1.795 + * for an exception of type E."
1.796 + * Thus we have a single type matching rule.
1.797 + */
1.798 +
1.799 +/* Helper macros: */
1.800 +
1.801 +#define CV_quals_of_pointee(P) (((const abi::__pbase_type_info *)(P))->__flags & \
1.802 + (abi::__pbase_type_info::__const_mask | \
1.803 + abi::__pbase_type_info::__volatile_mask))
1.804 +
1.805 +#define is_const(QUALS) (((QUALS) & abi::__pbase_type_info::__const_mask) != 0)
1.806 +
1.807 +#define any_qualifier_missing(TEST_QUALS, REF_QUALS) ((~(TEST_QUALS) & (REF_QUALS)) != 0)
1.808 +
1.809 +/* A routine is required for derived class to base class conversion.
1.810 + * This is obtained via a macro definition DERIVED_TO_BASE_CONVERSION
1.811 + * in unwind_env.h.
1.812 + */
1.813 +
1.814 +/* External entry point:
1.815 + * Type check the c++ rtti object for compatibility against the type of
1.816 + * the object containing the ucb. Return a pointer to the matched object
1.817 + * (possibly a non-leftmost baseclass of the exception object)
1.818 + */
1.819 +bool __cxa_type_match(UCB *ucbp, const type_info *match_type, void **matched_objectpp)
1.820 +{
1.821 + if (NAMES::is_foreign_exception(ucbp))
1.822 + return false;
1.823 +
1.824 + __cxa_exception *ep = ucbp_to_ep(ucbp);
1.825 + const type_info *throw_type = ep->exceptionType;
1.826 + bool previous_qualifiers_include_const = true; // for pointer qualification conversion
1.827 + unsigned int pointer_depth = 0;
1.828 + void *original_objectp = ep + 1;
1.829 + void *current_objectp = original_objectp;
1.830 +
1.831 + for (;;) {
1.832 +
1.833 + // Match if identical
1.834 +
1.835 + if (throw_type == match_type) {
1.836 + *matched_objectpp = original_objectp;
1.837 +#ifdef PRINTED_DIAGNOSTICS
1.838 + printf("__cxa_type_match: success (exact match after any ptrs)\n");
1.839 +#endif
1.840 + return true;
1.841 + }
1.842 +
1.843 + // Fail if one is a pointer and the other isn't
1.844 +
1.845 + const type_info *type_throw_type = &typeid(*throw_type);
1.846 + const type_info *type_match_type = &typeid(*match_type);
1.847 +
1.848 + if ((type_throw_type == &typeid(abi::__pointer_type_info) ||
1.849 + type_match_type == &typeid(abi::__pointer_type_info)) &&
1.850 + type_throw_type != type_match_type) {
1.851 +#ifdef PRINTED_DIAGNOSTICS
1.852 + printf("__cxa_type_match: failed (mixed ptr/non-ptr)\n");
1.853 +#endif
1.854 + return false;
1.855 + }
1.856 +
1.857 + // Both are pointers or neither is
1.858 + if (type_throw_type == &typeid(abi::__pointer_type_info)) {
1.859 + // Both are pointers
1.860 +#ifdef PRINTED_DIAGNOSTICS
1.861 + printf("__cxa_type_match: throwing a ptr\n");
1.862 +#endif
1.863 + pointer_depth++;
1.864 + // Check match_type is at least as CV-qualified as throw_type
1.865 + unsigned int match_quals = CV_quals_of_pointee(match_type);
1.866 + unsigned int throw_quals = CV_quals_of_pointee(throw_type);
1.867 + if (any_qualifier_missing(match_quals, throw_quals)) {
1.868 +#ifdef PRINTED_DIAGNOSTICS
1.869 + printf("__cxa_type_match: failed (missing qualifiers)\n");
1.870 +#endif
1.871 + return false;
1.872 + }
1.873 + // If the match type has additional qualifiers not found in the
1.874 + // throw type, any previous qualifiers must have included const
1.875 + if (any_qualifier_missing(throw_quals, match_quals) &&
1.876 + !previous_qualifiers_include_const) {
1.877 +#ifdef PRINTED_DIAGNOSTICS
1.878 + printf("__cxa_type_match: failed (not all qualifiers have const)\n");
1.879 +#endif
1.880 + return false;
1.881 + }
1.882 + if (!is_const(match_quals))
1.883 + previous_qualifiers_include_const = false;
1.884 + throw_type = ((const abi::__pbase_type_info *)throw_type)->__pointee;
1.885 + match_type = ((const abi::__pbase_type_info *)match_type)->__pointee;
1.886 + if (current_objectp != NULL)
1.887 + current_objectp = *(void **)current_objectp;
1.888 + continue;
1.889 + }
1.890 +
1.891 + // Neither is a pointer now but qualification conversion has been done.
1.892 + // See if pointer conversion on the original was possible.
1.893 + // T* will match void*
1.894 +
1.895 + if (pointer_depth == 1 && match_type == &typeid(void)) {
1.896 + *matched_objectpp = original_objectp;
1.897 +#ifdef PRINTED_DIAGNOSTICS
1.898 + printf("__cxa_type_match: success(conversion to void *)\n");
1.899 +#endif
1.900 + return true;
1.901 + }
1.902 +
1.903 + // Else if we have 2 class types, a derived class is matched by a
1.904 + // non-ambiguous public base class (perhaps not a leftmost one).
1.905 + // __si_class_type_info and __vmi_class_type_info are classes with bases.
1.906 +
1.907 + void *matched_base_p;
1.908 +
1.909 + if (pointer_depth < 2 &&
1.910 + (type_throw_type == &typeid(abi::__si_class_type_info) ||
1.911 + type_throw_type == &typeid(abi::__vmi_class_type_info))) {
1.912 + if (DERIVED_TO_BASE_CONVERSION(current_objectp, &matched_base_p,
1.913 + throw_type, match_type)) {
1.914 +#ifdef PRINTED_DIAGNOSTICS
1.915 + printf("__cxa_type_match: success (matched base 0x%x of 0x%x%s, thrown object 0x%x)\n",
1.916 + matched_base_p, current_objectp,
1.917 + pointer_depth == 0 ? "" : " via ptr",
1.918 + original_objectp);
1.919 +#endif
1.920 + *matched_objectpp = pointer_depth == 0 ? matched_base_p : original_objectp;
1.921 + return true;
1.922 + } else {
1.923 +#ifdef PRINTED_DIAGNOSTICS
1.924 + printf("__cxa_type_match: failed (derived to base failed)\n");
1.925 +#endif
1.926 + return false;
1.927 + }
1.928 + }
1.929 +
1.930 +#ifdef PRINTED_DIAGNOSTICS
1.931 + printf("__cxa_type_match: failed (types simply differ)\n");
1.932 +#endif
1.933 + return false;
1.934 + } /* for */
1.935 +}
1.936 +
1.937 +
1.938 +/* For debugging purposes: */
1.939 +#ifdef DEBUG
1.940 +extern "C" bool debug__cxa_type_match(void *objptr,
1.941 + const type_info *throw_type,
1.942 + const type_info *catch_type,
1.943 + void **matched_objectpp)
1.944 +{
1.945 + /* Create enough of an exception object that the type-matcher can run, then
1.946 + * check the type. Objptr is expected to be the result of a call to
1.947 + * __cxa_allocate_exception, which has then been copy-constructed.
1.948 + */
1.949 + __cxa_exception *e = ((__cxa_exception *)objptr) - 1;
1.950 + e->exceptionType = throw_type;
1.951 + return __cxa_type_match(&e->ucb, catch_type, matched_objectpp);
1.952 +}
1.953 +#endif
1.954 +
1.955 +
1.956 +#endif /* arm_exceptions_throw_c */
1.957 +#ifdef arm_exceptions_rethrow_c
1.958 +
1.959 +/* Redeclare _Unwind_RaiseException as weak (if WEAKDECL is defined
1.960 + * appropriately) so the use from __cxa_rethrow does not on its own
1.961 + * force the unwind library to be loaded.
1.962 + */
1.963 +
1.964 +extern "C" WEAKDECL _Unwind_Reason_Code _Unwind_RaiseException(UCB *ucbp);
1.965 +
1.966 +#pragma exceptions_unwind
1.967 +
1.968 +void __cxa_rethrow(void)
1.969 +{
1.970 + // Recover the exception object - it is the most recent caught exception object
1.971 + __cxa_eh_globals *g = __cxa_get_globals();
1.972 + __cxa_exception *ep = g->caughtExceptions;
1.973 + bool foreign;
1.974 +
1.975 + // Must call terminate here if no such exception
1.976 + if (ep == NULL) NAMES::call_terminate_handler(NULL);
1.977 +
1.978 + UCB *ucbp = &ep->ucb;
1.979 +
1.980 + // Mark the object as being propagated by throw, preventing multiple
1.981 + // propagation and also permitting __cxa_end_catch to do the right
1.982 + // thing when it is called from the handler's cleanup.
1.983 +
1.984 + ep->propagationCount++;
1.985 +
1.986 + // Now reraise, taking care with foreign exceptions
1.987 +
1.988 + foreign = NAMES::is_foreign_exception(ucbp);
1.989 + if (foreign) {
1.990 + // Indirect through the intermediate object to the foreign ucb
1.991 + ucbp = (UCB *)ep->exceptionType;
1.992 + } else {
1.993 + // Increment the uncaught C++ exceptions count
1.994 + g->uncaughtExceptions++;
1.995 + }
1.996 +
1.997 + // Tell debugger what's happening
1.998 +
1.999 + DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_STARTING, foreign ? NULL : ep->exceptionType);
1.1000 +
1.1001 + // Initiate unwinding - if we get control back, call C++ routine terminate()
1.1002 +
1.1003 + _Unwind_RaiseException(ucbp);
1.1004 +
1.1005 +#ifdef PRINTED_DIAGNOSTICS
1.1006 + printf("__cxa_rethrow: throw failed\n");
1.1007 +#endif
1.1008 +
1.1009 + __cxa_call_terminate(ucbp);
1.1010 +}
1.1011 +
1.1012 +#endif /* arm_exceptions_rethrow_c */
1.1013 +#ifdef arm_exceptions_foreign_c
1.1014 +
1.1015 +/* During catch and cleanup, foreign exception objects are dealt with using
1.1016 + * an intermediate __cxa_exception block in the appropriate exceptions
1.1017 + * chain. This block has the same exception_class as the real foreign
1.1018 + * ucb, and points to the real ucb via the intermediate block's exceptionType
1.1019 + * field. This helper function checks whether it has been passed such an
1.1020 + * intermediate block and sets one up if not. Only call it when the UCB
1.1021 + * is known to belong to a foreign exception.
1.1022 + */
1.1023 +
1.1024 +__cxa_exception *NAMES::get_foreign_intermediary(__cxa_exception *head_ep, UCB *ucbp)
1.1025 +{
1.1026 + if (head_ep != NULL) {
1.1027 + UCB *head_ucbp = &head_ep->ucb;
1.1028 + if (NAMES::same_exceptions_class(&head_ucbp->exception_class, &ucbp->exception_class) &&
1.1029 + (UCB *)head_ep->exceptionType == ucbp)
1.1030 + return head_ep;
1.1031 + }
1.1032 +
1.1033 + // Create an intermediate block. Only initialise as much as necessary
1.1034 + __cxa_exception *ep = ((__cxa_exception *)__cxa_allocate_exception(0)) - 1;
1.1035 + UCB *new_ucbp = &ep->ucb;
1.1036 + memcpy(new_ucbp->exception_class, ucbp->exception_class, EXCEPTIONS_CLASS_SIZE);
1.1037 + ep->propagationCount = 0; // Not propagating
1.1038 + ep->handlerCount = 0; // Not handled
1.1039 + ep->nextCaughtException = NULL; // Not in chain
1.1040 + ep->exceptionType = (const type_info *)ucbp; // The foreign UCB
1.1041 + return ep;
1.1042 +}
1.1043 +
1.1044 +
1.1045 +#endif /* arm_exceptions_foreign_c */
1.1046 +#ifdef arm_exceptions_cleanup_c
1.1047 +
1.1048 +bool __cxa_begin_cleanup(UCB *ucbp)
1.1049 +{
1.1050 + // Indicate that a cleanup is about to start.
1.1051 + // Save the exception pointer over the cleanup for recovery later, using a chain.
1.1052 + // If we allowed the exception to be rethrown in a cleanup, then
1.1053 + // the object might appear multiple times at the head of this chain,
1.1054 + // and the propagationCount could be used to track this - at this point,
1.1055 + // the object is logically in the chain propagationCount-1 times, and
1.1056 + // physically 0 or 1 times. Thus if propagationCount == 1 we should insert
1.1057 + // it physically. A similar rule is used for physical removal in
1.1058 + //__cxa_end_cleanup.
1.1059 + // Foreign exceptions are handled via an intermediate __cxa_exception object
1.1060 + // in a similar way as __cxa_begin_catch.
1.1061 +
1.1062 + __cxa_eh_globals *g = __cxa_get_globals();
1.1063 + __cxa_exception *ep;
1.1064 +
1.1065 + if (NAMES::is_foreign_exception(ucbp)) {
1.1066 + ep = NAMES::get_foreign_intermediary(g->propagatingExceptions, ucbp);
1.1067 + ep->propagationCount++; // Indicate one (or one additional) propagation
1.1068 + } else {
1.1069 + ep = ucbp_to_ep(ucbp);
1.1070 + }
1.1071 +
1.1072 + if (ep->propagationCount == 1) {
1.1073 + // Insert into chain
1.1074 + ep->nextPropagatingException = g->propagatingExceptions;
1.1075 + g->propagatingExceptions = ep;
1.1076 + }
1.1077 +
1.1078 + return true;
1.1079 +}
1.1080 +
1.1081 +
1.1082 +// Helper function for __cxa_end_cleanup
1.1083 +
1.1084 +extern "C" UCB * __ARM_cxa_end_cleanup(void)
1.1085 +{
1.1086 + // Recover and return the currently propagating exception (from the
1.1087 + // head of the propagatingExceptions chain).
1.1088 + // propagationCount at this moment is a logical count of how many times the
1.1089 + // item is in the chain so physically unchain it when this count is 1.
1.1090 + // Foreign exceptions use an intermediary.
1.1091 +
1.1092 + __cxa_eh_globals *g = __cxa_get_globals();
1.1093 + __cxa_exception *ep = g->propagatingExceptions;
1.1094 +
1.1095 + if (ep == NULL) terminate();
1.1096 +
1.1097 + UCB *ucbp = &ep->ucb;
1.1098 + if (NAMES::is_foreign_exception(ucbp)) {
1.1099 + // Get the foreign ucb
1.1100 + ucbp = (UCB *)ep->exceptionType;
1.1101 + if (ep->propagationCount == 1) {
1.1102 + // Free the intermediate ucb (see description in __cxa_begin_catch)
1.1103 + void *eop = (void *)(ep + 1);
1.1104 + g->propagatingExceptions = ep->nextPropagatingException;
1.1105 + __cxa_free_exception(eop);
1.1106 + } else {
1.1107 + ep->propagationCount--;
1.1108 + }
1.1109 + } else {
1.1110 + // Not foreign
1.1111 + if (ep->propagationCount == 1) { // logically in chain once - so unchain
1.1112 + g->propagatingExceptions = ep->nextPropagatingException;
1.1113 + }
1.1114 + }
1.1115 + return ucbp;
1.1116 +}
1.1117 +
1.1118 +// __cxa_end_cleanup is called at the end of a cleanup fragment.
1.1119 +// It must do the C++ housekeeping, then call _Unwind_Resume, but it must
1.1120 +// damage no significant registers in the process.
1.1121 +
1.1122 +__asm void __cxa_end_cleanup(void) {
1.1123 + extern __ARM_cxa_end_cleanup;
1.1124 + extern _Unwind_Resume WEAKASMDECL;
1.1125 +
1.1126 +#ifdef __thumb
1.1127 + preserve8; // This is preserve8 (ARM assembler heuristics are inadequate)
1.1128 + push {r1-r7};
1.1129 + mov r2, r8;
1.1130 + mov r3, r9;
1.1131 + mov r4, r10;
1.1132 + mov r5, r11;
1.1133 + push {r1-r5};
1.1134 + bl __ARM_cxa_end_cleanup; // returns UCB address in r0
1.1135 + pop {r1-r5};
1.1136 + mov r8, r2;
1.1137 + mov r9, r3;
1.1138 + mov r10, r4;
1.1139 + mov r11, r5;
1.1140 + pop {r1-r7};
1.1141 + bl _Unwind_Resume; // won't return
1.1142 +#else
1.1143 + stmfd r13!, {r1-r12}
1.1144 + bl __ARM_cxa_end_cleanup; // returns UCB address in r0
1.1145 + ldmia r13!, {r1-r12};
1.1146 + b _Unwind_Resume; // won't return
1.1147 +#endif
1.1148 +}
1.1149 +
1.1150 +
1.1151 +#endif /* arm_exceptions_cleanup_c */
1.1152 +#ifdef arm_exceptions_catchsemantics_c
1.1153 +
1.1154 +/* Update date structures as if catching an object.
1.1155 + * Call this from __cxa_begin_catch when actually catching an object,
1.1156 + * and from external_exception_termination when called by a foreign runtime
1.1157 + * after one of our objects was caught.
1.1158 + */
1.1159 +
1.1160 +void NAMES::eh_catch_semantics(UCB *ucbp)
1.1161 +{
1.1162 + __cxa_eh_globals *g = __cxa_get_globals();
1.1163 + __cxa_exception *ep;
1.1164 +
1.1165 + if (NAMES::is_foreign_exception(ucbp)) {
1.1166 + // Foreign exception. Get the associated intermediary block or
1.1167 + // make one if there isn't one already.
1.1168 + // In the case of a rethrow, the foreign object may already be on
1.1169 + // the handled exceptions chain (it will be first).
1.1170 + ep = NAMES::get_foreign_intermediary(g->caughtExceptions, ucbp);
1.1171 + } else {
1.1172 + // Not foreign
1.1173 + ep = ucbp_to_ep(ucbp);
1.1174 + // Decrement the propagation count
1.1175 + ep->propagationCount--;
1.1176 + // Decrement the total uncaught C++ exceptions count
1.1177 + g->uncaughtExceptions--;
1.1178 + }
1.1179 +
1.1180 + // Common code for our EO's, and foreign ones where we work on the intermediate EO
1.1181 +
1.1182 + // Increment the handler count for this exception object
1.1183 + ep->handlerCount++;
1.1184 +
1.1185 + // Push the ep onto the "handled exceptions" chain if it is not already there.
1.1186 + // (If catching a rethrow, it may already be there)
1.1187 +
1.1188 + if (ep->nextCaughtException == NULL) {
1.1189 + ep->nextCaughtException = g->caughtExceptions;
1.1190 + g->caughtExceptions = ep;
1.1191 + }
1.1192 +}
1.1193 +
1.1194 +
1.1195 +#endif /* arm_exceptions_catchsemantics_c */
1.1196 +#ifdef arm_exceptions_begincatch_c
1.1197 +
1.1198 +void *__cxa_begin_catch(UCB *ucbp)
1.1199 +{
1.1200 + void *match = (void *)ucbp->barrier_cache.bitpattern[0]; // The matched object, if any
1.1201 +
1.1202 + // Update the data structures
1.1203 +
1.1204 + NAMES::eh_catch_semantics(ucbp);
1.1205 +
1.1206 + // Tell the unwinder the exception propagation has finished,
1.1207 + // and return the object pointer
1.1208 +
1.1209 + _Unwind_Complete(ucbp);
1.1210 + return match;
1.1211 +}
1.1212 +
1.1213 +
1.1214 +#endif /* arm_exceptions_begincatch_c */
1.1215 +#ifdef arm_exceptions_endcatch_c
1.1216 +
1.1217 +#pragma exceptions_unwind
1.1218 +
1.1219 +void __cxa_end_catch(void)
1.1220 +{
1.1221 + // Recover the exception object - it is the most recent caught exception object
1.1222 + __cxa_eh_globals *g = __cxa_get_globals();
1.1223 + __cxa_exception *ep = g->caughtExceptions;
1.1224 +
1.1225 + if (ep == NULL) terminate();
1.1226 +
1.1227 + // Rethrow in progress?
1.1228 +
1.1229 + bool object_being_rethrown = ep->propagationCount != 0;
1.1230 +
1.1231 + // Decrement the handler count for this exception object
1.1232 + ep->handlerCount--;
1.1233 +
1.1234 + // Unstack the object if it is no longer being handled anywhere.
1.1235 + // Destroy and free the object if it is no longer alive -
1.1236 + // it is dead if its handler count becomes 0, unless it is
1.1237 + // about to be rethrown.
1.1238 + // If the dtor throws, allow its exception to propagate.
1.1239 + // Do different things if it is a foreign exception object.
1.1240 +
1.1241 + if (ep->handlerCount == 0) {
1.1242 + void *eop = (void *)(ep + 1);
1.1243 + UCB *ucbp = &ep->ucb;
1.1244 + bool foreign = NAMES::is_foreign_exception(ucbp);
1.1245 +
1.1246 + // Unstack it from the caught exceptions stack - it is guaranteed to be top item.
1.1247 + g->caughtExceptions = ep->nextCaughtException;
1.1248 +
1.1249 + if (foreign) {
1.1250 + // Get the foreign ucb and free the intermediate ucb (see description in __cxa_begin_catch)
1.1251 + ucbp = (UCB *)ep->exceptionType;
1.1252 + __cxa_free_exception(eop);
1.1253 + } else {
1.1254 + ep->nextCaughtException = NULL; // So __cxa_begin_catch knows it isn't in the chain
1.1255 + }
1.1256 +
1.1257 + // Now destroy the exception object if it's no longer needed
1.1258 + if (!object_being_rethrown) {
1.1259 + if (foreign) {
1.1260 +
1.1261 + // Notify the foreign language, if it so requested
1.1262 + if (ucbp->exception_cleanup != NULL)
1.1263 + (ucbp->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT, ucbp);
1.1264 +
1.1265 + } else {
1.1266 +
1.1267 + // One of our objects: do C++-specific semantics
1.1268 +
1.1269 + if (ep->exceptionDestructor != NULL) {
1.1270 + // Run the dtor. If it throws, free the memory anyway and
1.1271 + // propagate the new exception.
1.1272 +#ifdef ARM_EXCEPTIONS_ENABLED
1.1273 + try {
1.1274 + (ep->exceptionDestructor)(eop);
1.1275 + } catch(...) {
1.1276 + // Free the memory and reraise
1.1277 + __cxa_free_exception(eop);
1.1278 + throw;
1.1279 + }
1.1280 +#else
1.1281 + (ep->exceptionDestructor)(eop);
1.1282 +#endif
1.1283 + }
1.1284 + // Dtor (if there was one) didn't throw. Free the memory.
1.1285 + __cxa_free_exception(eop);
1.1286 + } // !foreign
1.1287 + } // !object_being_rethrown
1.1288 + } // ep->handlerCount == 0
1.1289 +}
1.1290 +
1.1291 +
1.1292 +#endif /* arm_exceptions_endcatch_c */
1.1293 +#ifdef arm_exceptions_bad_typeid_c
1.1294 +
1.1295 +#pragma exceptions_unwind
1.1296 +
1.1297 +void __cxa_bad_typeid(void)
1.1298 +{
1.1299 + throw std::bad_typeid();
1.1300 +}
1.1301 +
1.1302 +
1.1303 +#endif /* arm_exceptions_bad_typeid_c */
1.1304 +#ifdef arm_exceptions_bad_cast_c
1.1305 +
1.1306 +#pragma exceptions_unwind
1.1307 +
1.1308 +void __cxa_bad_cast(void)
1.1309 +{
1.1310 + throw std::bad_cast();
1.1311 +}
1.1312 +
1.1313 +
1.1314 +#endif /* arm_exceptions_bad_cast_c */