source: libcfa/src/exception.c@ 6c58850

Last change on this file since 6c58850 was 30548de, checked in by Peter A. Buhr <pabuhr@…>, 5 months ago

change manipulator name quoted to quote
  • Property mode set to 100644
File size: 21.9 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// exception.c --
8//
9// Author : Andrew Beach
10// Created On : Mon Jun 26 15:13:00 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Wed Sep 25 17:23:49 2024
13// Update Count : 74
14//
15
16// Normally we would get this from the CFA prelude.
17#include <stddef.h> // for size_t
18
19#include <unwind.h> // for struct _Unwind_Exception {...};
20
21#include "exception.h"
22
23#include <stdlib.h>
24#include <stdio.h>
25#include <bits/debug.hfa>
26#include "concurrency/invoke.h"
27#include "stdhdr/assert.h"
28#include "virtual.h"
29#include <unistd.h> // write
30
31extern void __cabi_abort( const char fmt[], ... );
32
33#pragma GCC visibility push(default)
34
35#include "lsda.h"
36
37/* The exception class for our exceptions. Because of the vendor component
38 * its value would not be standard.
39 * Vendor: UWPL
40 * Language: CFA\0
41 */
42const _Unwind_Exception_Class __cfaehm_exception_class = 0x4c50575500414643;
43
44// Base Exception type id:
45struct __cfavir_type_info __cfatid_exception_t = {
46 NULL,
47};
48
49
50// Get the current exception context.
51// There can be a single global until multithreading occurs, then each stack
52// needs its own. We get this from libcfathreads (no weak attribute).
53__attribute__((weak)) struct exception_context_t * this_exception_context() {
54 static struct exception_context_t shared_stack = {NULL, NULL};
55 return &shared_stack;
56}
57
58struct __cfaehm_base_exception_t * __cfaehm_get_current_termination(void) {
59 return this_exception_context()->current_exception;
60}
61
62
63// RESUMPTION ================================================================
64
65static void reset_top_resume(struct __cfaehm_try_resume_node ** store) {
66 this_exception_context()->top_resume = *store;
67}
68
69void __cfaehm_throw_resume(exception_t * except, void (*defaultHandler)(exception_t *)) {
70 struct exception_context_t * context = this_exception_context();
71
72 __cfadbg_print_safe(exception, "Throwing resumption exception\n");
73
74 {
75 __attribute__((cleanup(reset_top_resume)))
76 struct __cfaehm_try_resume_node * original_head = context->top_resume;
77 struct __cfaehm_try_resume_node * current = context->top_resume;
78
79 for ( ; current ; current = current->next) {
80 context->top_resume = current->next;
81 if (current->handler(except)) {
82 return;
83 }
84 }
85 } // End the search and return to the top of the stack.
86
87 // No handler found, fall back to the default operation.
88 __cfadbg_print_safe(exception, "Unhandled exception\n");
89 defaultHandler(except);
90}
91
92// Do we control where exceptions get thrown even with concurency?
93// If not these are not quite thread safe, the cleanup hook has to
94// be added after the node is built but before it is made the top node.
95
96void __cfaehm_try_resume_setup(struct __cfaehm_try_resume_node * node,
97 _Bool (*handler)(exception_t * except)) {
98 struct exception_context_t * context = this_exception_context();
99 node->next = context->top_resume;
100 node->handler = handler;
101 context->top_resume = node;
102}
103
104void __cfaehm_try_resume_cleanup(struct __cfaehm_try_resume_node * node) {
105 struct exception_context_t * context = this_exception_context();
106 context->top_resume = node->next;
107}
108
109
110// MEMORY MANAGEMENT =========================================================
111
112#define NODE_TO_EXCEPT(node) ((exception_t *)(1 + (node)))
113#define EXCEPT_TO_NODE(except) ((struct __cfaehm_node *)(except) - 1)
114#define UNWIND_TO_NODE(unwind) ((struct __cfaehm_node *)(unwind))
115#define NULL_MAP(map, ptr) ((ptr) ? (map(ptr)) : NULL)
116
117// How to clean up an exception in various situations.
118static void __cfaehm_exception_cleanup(
119 _Unwind_Reason_Code reason,
120 struct _Unwind_Exception * exception) {
121 switch (reason) {
122 case _URC_FOREIGN_EXCEPTION_CAUGHT:
123 // This one we could clean-up to allow cross-language exceptions.
124 case _URC_FATAL_PHASE1_ERROR:
125 case _URC_FATAL_PHASE2_ERROR:
126 default:
127 write( 2, "abort1\n", 7 );
128 abort();
129 }
130}
131
132// Creates a copy of the indicated exception and sets current_exception to it.
133void __cfaehm_allocate_exception( exception_t * except ) {
134 struct exception_context_t * context = this_exception_context();
135
136 // Allocate memory for the exception.
137 struct __cfaehm_node * store = malloc(
138 sizeof( struct __cfaehm_node ) + except->virtual_table->size );
139
140 if ( ! store ) {
141 // Failure: cannot allocate exception. Terminate thread.
142 write( 2, "abort2\n", 7 );
143 abort(); // <- Although I think it might be the process.
144 }
145
146 // Initialize the node:
147 exception_t * except_store = NODE_TO_EXCEPT(store);
148 store->unwind_exception.exception_class = __cfaehm_exception_class;
149 store->unwind_exception.exception_cleanup = __cfaehm_exception_cleanup;
150 store->handler_index = 0;
151 except->virtual_table->copy( except_store, except );
152
153 // Add the node to the list:
154 store->next = NULL_MAP(EXCEPT_TO_NODE, context->current_exception);
155 context->current_exception = except_store;
156}
157
158// Delete the provided exception, unsetting current_exception if relivant.
159static void __cfaehm_delete_exception( exception_t * except ) {
160 struct exception_context_t * context = this_exception_context();
161
162 __cfadbg_print_safe(exception, "Deleting Exception\n");
163
164 // Remove the exception from the list.
165 struct __cfaehm_node * to_free = EXCEPT_TO_NODE(except);
166 struct __cfaehm_node * node;
167
168 if ( context->current_exception == except ) {
169 node = to_free->next;
170 context->current_exception = NULL_MAP(NODE_TO_EXCEPT, node);
171 } else {
172 node = EXCEPT_TO_NODE(context->current_exception);
173 // It may always be in the first or second position.
174 while ( to_free != node->next ) {
175 node = node->next;
176 }
177 node->next = to_free->next;
178 }
179
180 // Free the old exception node.
181 except->virtual_table->free( except );
182 free( to_free );
183}
184
185// CANCELLATION ==============================================================
186
187// Function needed by force unwind
188// It basically says to unwind the whole stack and then exit when we reach the end of the stack
189static _Unwind_Reason_Code _Stop_Fn(
190 int version,
191 _Unwind_Action actions,
192 _Unwind_Exception_Class exception_class,
193 struct _Unwind_Exception * unwind_exception,
194 struct _Unwind_Context * unwind_context,
195 void * stop_param) {
196 // Verify actions follow the rules we expect.
197 verify(actions & _UA_CLEANUP_PHASE);
198 verify(actions & _UA_FORCE_UNWIND);
199 verify(!(actions & _UA_SEARCH_PHASE));
200 verify(!(actions & _UA_HANDLER_FRAME));
201
202 if ( actions & _UA_END_OF_STACK ) {
203 __cabi_abort(
204 "Propagation failed to find a matching handler.\n"
205 "Possible cause is a missing try block with appropriate catch clause for the specified or derived exception type.\n"
206 "Last exception name or message: %s.\n",
207 NODE_TO_EXCEPT( UNWIND_TO_NODE( unwind_exception ) )->
208 virtual_table->msg( NODE_TO_EXCEPT( UNWIND_TO_NODE( unwind_exception ) ) )
209 );
210 } else {
211 return _URC_NO_REASON;
212 }
213}
214
215__attribute__((weak)) _Unwind_Reason_Code
216__cfaehm_cancellation_unwind( struct _Unwind_Exception * exception ) {
217 return _Unwind_ForcedUnwind( exception, _Stop_Fn, (void*)0x22 );
218}
219
220// Cancel the current stack, prefroming approprate clean-up and messaging.
221void __cfaehm_cancel_stack( exception_t * exception ) {
222 __cfaehm_allocate_exception( exception );
223
224 struct exception_context_t * context = this_exception_context();
225 struct __cfaehm_node * node = EXCEPT_TO_NODE(context->current_exception);
226
227 _Unwind_Reason_Code ret;
228 ret = __cfaehm_cancellation_unwind( &node->unwind_exception );
229 printf("UNWIND ERROR %d after force unwind\n", ret);
230 write( 2, "abort3\n", 7 );
231 abort();
232}
233
234
235// TERMINATION ===============================================================
236
237// If this isn't a rethrow (*except==0), delete the provided exception.
238void __cfaehm_cleanup_terminate( void * except ) {
239 if ( *(void**)except ) __cfaehm_delete_exception( *(exception_t **)except );
240}
241
242static void __cfaehm_cleanup_default( exception_t ** except ) {
243 __cfaehm_delete_exception( *except );
244 *except = NULL;
245}
246
247// The exception that is being thrown must already be stored.
248void __cfaehm_begin_unwind(void(*defaultHandler)(exception_t *)) {
249 struct exception_context_t * context = this_exception_context();
250 if ( NULL == context->current_exception ) {
251 printf("UNWIND ERROR missing exception in begin unwind\n");
252 write( 2, "abort4\n", 7 );
253 abort();
254 }
255 struct _Unwind_Exception * storage =
256 &EXCEPT_TO_NODE(context->current_exception)->unwind_exception;
257
258 // Call stdlibc to raise the exception
259 __cfadbg_print_safe(exception, "Begin unwinding (storage &p, context %p)\n", storage, context);
260 _Unwind_Reason_Code ret = _Unwind_RaiseException( storage );
261
262 // If we reach here it means something happened. For resumption to work we need to find a way
263 // to return back to here. Most of them will probably boil down to setting a global flag and
264 // making the phase 1 either stop or fail. Causing an error on purpose may help avoiding
265 // unnecessary work but it might have some weird side effects. If we just pretend no handler
266 // was found that would work but may be expensive for no reason since we will always search
267 // the whole stack.
268
269#if defined( __x86_64 ) || defined( __i386 )
270 // We did not simply reach the end of the stack without finding a handler. This is an error.
271 if ( ret != _URC_END_OF_STACK ) {
272#else // defined( __ARM_ARCH )
273 // The return code from _Unwind_RaiseException seems to be corrupt on ARM at end of stack.
274 // This workaround tries to keep default exception handling working.
275 if ( ret == _URC_FATAL_PHASE1_ERROR || ret == _URC_FATAL_PHASE2_ERROR ) {
276#endif
277 printf("UNWIND ERROR %d after raise exception\n", ret);
278 write( 2, "abort5\n", 7 );
279 abort();
280 }
281
282 // No handler found, go to the default operation.
283 __cfadbg_print_safe(exception, "Uncaught exception %p\n", storage);
284
285 __attribute__((cleanup(__cfaehm_cleanup_default)))
286 exception_t * exception = context->current_exception;
287 defaultHandler( exception );
288}
289
290void __cfaehm_throw_terminate( exception_t * val, void (*defaultHandler)(exception_t *) ) {
291 __cfadbg_print_safe(exception, "Throwing termination exception\n");
292
293 __cfaehm_allocate_exception( val );
294 __cfaehm_begin_unwind( defaultHandler );
295}
296
297static __attribute__((noreturn)) void __cfaehm_rethrow_adapter( exception_t * except ) {
298 // TODO: Print some error message.
299 (void)except;
300 write( 2, "abort6\n", 7 );
301 abort();
302}
303
304void __cfaehm_rethrow_terminate(void) {
305 __cfadbg_print_safe(exception, "Rethrowing termination exception\n");
306
307 __cfaehm_begin_unwind( __cfaehm_rethrow_adapter );
308 write( 2, "abort7\n", 7 );
309 abort();
310}
311
312#if defined( __x86_64 ) || defined( __i386 ) || defined( __ARM_ARCH )
313// This is our personality routine. For every stack frame annotated with
314// ".cfi_personality 0x3,__gcfa_personality_v0" this function will be called twice when unwinding.
315// Once in the search phase and once in the cleanup phase.
316_Unwind_Reason_Code __gcfa_personality_v0(
317 int version,
318 _Unwind_Action actions,
319 unsigned long long exception_class,
320 struct _Unwind_Exception * unwind_exception,
321 struct _Unwind_Context * unwind_context)
322{
323 __cfadbg_print_safe(exception, "CFA: 0x%p\n", (void*)_Unwind_GetCFA(unwind_context));
324 __cfadbg_print_safe(exception, "Personality function (%d, %x, %llu, %p, %p):",
325 version, actions, exception_class, unwind_exception, unwind_context);
326
327 // Verify that actions follow the rules we expect.
328 // This function should never be called at the end of the stack.
329 verify(!(actions & _UA_END_OF_STACK));
330 // Either only the search phase flag is set or...
331 if (actions & _UA_SEARCH_PHASE) {
332 verify(actions == _UA_SEARCH_PHASE);
333 __cfadbg_print_safe(exception, " lookup phase");
334 // ... we are in clean-up phase.
335 } else {
336 verify(actions & _UA_CLEANUP_PHASE);
337 __cfadbg_print_safe(exception, " cleanup phase");
338 // We shouldn't be the handler frame during forced unwind.
339 if (actions & _UA_HANDLER_FRAME) {
340 verify(!(actions & _UA_FORCE_UNWIND));
341 __cfadbg_print_safe(exception, " (handler frame)");
342 } else if (actions & _UA_FORCE_UNWIND) {
343 __cfadbg_print_safe(exception, " (force unwind)");
344 }
345 }
346
347 // Get a pointer to the language specific data from which we will read what we need
348 const unsigned char * lsd = _Unwind_GetLanguageSpecificData( unwind_context );
349
350 if ( !lsd ) { //Nothing to do, keep unwinding
351 printf(" no LSD");
352 goto UNWIND;
353 }
354
355 // Get the instuction pointer and a reading pointer into the exception table
356 lsda_header_info lsd_info;
357 const unsigned char * cur_ptr = parse_lsda_header(unwind_context, lsd, &lsd_info);
358 _Unwind_Ptr instruction_ptr = _Unwind_GetIP(unwind_context);
359
360 struct exception_context_t * context = this_exception_context();
361
362 // Linearly search the table for stuff to do
363 while ( cur_ptr < lsd_info.action_table ) {
364 _Unwind_Ptr callsite_start;
365 _Unwind_Ptr callsite_len;
366 _Unwind_Ptr callsite_landing_pad;
367 _uleb128_t callsite_action;
368
369 // Decode the common stuff we have in here
370 cur_ptr = read_encoded_value(0, lsd_info.call_site_encoding, cur_ptr, &callsite_start);
371 cur_ptr = read_encoded_value(0, lsd_info.call_site_encoding, cur_ptr, &callsite_len);
372 cur_ptr = read_encoded_value(0, lsd_info.call_site_encoding, cur_ptr, &callsite_landing_pad);
373 cur_ptr = read_uleb128(cur_ptr, &callsite_action);
374
375 // Have we reach the correct frame info yet?
376 if ( lsd_info.Start + callsite_start + callsite_len < instruction_ptr ) {
377#ifdef __CFA_DEBUG_PRINT__
378 void * ls = (void*)lsd_info.Start;
379 void * cs = (void*)callsite_start;
380 void * cl = (void*)callsite_len;
381 void * bp = (void*)lsd_info.Start + callsite_start;
382 void * ep = (void*)lsd_info.Start + callsite_start + callsite_len;
383 void * ip = (void*)instruction_ptr;
384 __cfadbg_print_safe(exception, "\nfound %p - %p (%p, %p, %p), looking for %p\n",
385 bp, ep, ls, cs, cl, ip);
386#endif // __CFA_DEBUG_PRINT__
387 continue;
388 }
389
390 // Have we gone too far?
391 if ( lsd_info.Start + callsite_start > instruction_ptr ) {
392 printf(" gone too far");
393 break;
394 }
395
396 // Check for what we must do:
397 if ( 0 == callsite_landing_pad ) {
398 // Nothing to do, move along
399 __cfadbg_print_safe(exception, " no landing pad");
400 } else if (actions & _UA_SEARCH_PHASE) {
401 // In search phase, these means we found a potential handler we must check.
402
403 // We have arbitrarily decided that 0 means nothing to do and 1 means there is
404 // a potential handler. This doesn't seem to conflict the gcc default behavior.
405 if (callsite_action != 0) {
406 // Now we want to run some code to see if the handler matches
407 // This is the tricky part where we want to the power to run arbitrary code
408 // However, generating a new exception table entry and try routine every time
409 // is way more expansive than we might like
410 // The information we have is :
411 // - The GR (Series of registers)
412 // GR1=GP Global Pointer of frame ref by context
413 // - The instruction pointer
414 // - The instruction pointer info (???)
415 // - The CFA (Canonical Frame Address)
416 // - The BSP (Probably the base stack pointer)
417
418 // The current apprach uses one exception table entry per try block
419 _uleb128_t imatcher;
420 // Get the relative offset to the {...}?
421 cur_ptr = read_uleb128(cur_ptr, &imatcher);
422
423 _Unwind_Word match_pos =
424# if defined( __x86_64 )
425 _Unwind_GetCFA(unwind_context);
426# elif defined( __i386 )
427 _Unwind_GetCFA(unwind_context) + 20;
428# elif defined( __ARM_ARCH )
429 _Unwind_GetCFA(unwind_context) + 16;
430# endif
431 //! printf("match_pos: %p\n", (void*)match_pos);
432 //! fflush(stdout);
433 int (*matcher)(exception_t *) = *(int(**)(exception_t *))match_pos;
434
435 int index = matcher(context->current_exception);
436 _Unwind_Reason_Code ret = (0 == index)
437 ? _URC_CONTINUE_UNWIND : _URC_HANDLER_FOUND;
438 UNWIND_TO_NODE(unwind_exception)->handler_index = index;
439
440 // Based on the return value, check if we matched the exception
441 if (ret == _URC_HANDLER_FOUND) {
442 __cfadbg_print_safe(exception, " handler found\n");
443 } else {
444 // TODO: Continue the search if there is more in the table.
445 __cfadbg_print_safe(exception, " no handler\n");
446 }
447 return ret;
448 }
449
450 // This is only a cleanup handler, ignore it
451 __cfadbg_print_safe(exception, " no action");
452 } else {
453 // In clean-up phase, no destructors here but this could be the handler.
454
455 if ( (callsite_action != 0) && !(actions & _UA_HANDLER_FRAME) ){
456 // If this is a potential exception handler
457 // but not the one that matched the exception in the seach phase,
458 // just ignore it
459 goto UNWIND;
460 }
461
462 // We need to run some clean-up or a handler
463 // These statment do the right thing but I don't know any specifics at all
464 _Unwind_SetGR( unwind_context, __builtin_eh_return_data_regno(0),
465 (_Unwind_Ptr)unwind_exception );
466 _Unwind_SetGR( unwind_context, __builtin_eh_return_data_regno(1), 0 );
467
468 // I assume this sets the instruction pointer to the adress of the landing pad
469 // It doesn't actually set it, it only state the value that needs to be set once we
470 // return _URC_INSTALL_CONTEXT
471 _Unwind_SetIP( unwind_context, ((lsd_info.LPStart) + (callsite_landing_pad)) );
472
473 __cfadbg_print_safe(exception, " action\n");
474
475 // Return have some action to run
476 return _URC_INSTALL_CONTEXT;
477 }
478 }
479 // No handling found
480 __cfadbg_print_safe(exception, " table end reached");
481
482 UNWIND:
483 __cfadbg_print_safe(exception, " unwind\n");
484
485 // Keep unwinding the stack
486 return _URC_CONTINUE_UNWIND;
487}
488
489#pragma GCC push_options
490#pragma GCC optimize(0)
491
492// Try statements are hoisted out see comments for details. While this could probably be unique
493// and simply linked from libcfa but there is one problem left, see the exception table for details
494__attribute__((noinline))
495int __cfaehm_try_terminate(void (*try_block)(),
496 __attribute__((unused)) int (*match_block)(exception_t * except)) {
497 //! volatile int xy = 0;
498 //! printf("%p %p %p\n", &try_block, &match_block, &xy);
499 //! fflush(stdout);
500
501 // Setup the personality routine and exception table.
502 // Unforturnately these clobber gcc cancellation support which means we can't get access to
503 // the attribute cleanup tables at the same time. We would have to inspect the assembly to
504 // create a new set ourselves.
505#ifdef __PIC__
506 asm volatile (".cfi_personality 0x9b,CFA.ref.__gcfa_personality_v0");
507 asm volatile (".cfi_lsda 0x1b, .LLSDACFA2");
508#else
509 asm volatile (".cfi_personality 0x3,__gcfa_personality_v0");
510 asm volatile (".cfi_lsda 0x3, .LLSDACFA2");
511#endif
512
513 // Label which defines the start of the area for which the handler is setup.
514 asm volatile (".TRYSTART:");
515
516 // The actual statements of the try blocks
517 try_block();
518
519 // asm statement to prevent deadcode removal
520 asm volatile goto ("" : : : : CATCH );
521
522 // Normal return for when there is no throw.
523 return 0;
524
525 // Exceptionnal path
526 CATCH : __attribute__(( unused ));
527 // Label which defines the end of the area for which the handler is setup.
528 asm volatile (".TRYEND:");
529 // Label which defines the start of the exception landing pad. Basically what is called when
530 // the exception is caught. Note, if multiple handlers are given, the multiplexing should be
531 // done by the generated code, not the exception runtime.
532 asm volatile (".CATCH:");
533
534 return EXCEPT_TO_NODE( this_exception_context()->current_exception )->handler_index;
535}
536
537// Exception table data we need to generate. While this is almost generic, the custom data refers
538// to {*}try_terminate, which is no way generic. Some more works need to be done if we want to
539// have a single call to the try routine.
540
541#ifdef __PIC__
542asm (
543 // HEADER
544 ".LFECFA1:\n"
545#if defined( __x86_64 ) || defined( __i386 )
546 " .globl __gcfa_personality_v0\n"
547#else // defined( __ARM_ARCH )
548 " .global __gcfa_personality_v0\n"
549#endif
550 " .section .gcc_except_table,\"a\",@progbits\n"
551 // TABLE HEADER (important field is the BODY length at the end)
552 ".LLSDACFA2:\n"
553 " .byte 0xff\n"
554 " .byte 0xff\n"
555 " .byte 0x1\n"
556 " .uleb128 .LLSDACSECFA2-.LLSDACSBCFA2\n"
557 // BODY (language specific data)
558 // This uses language specific data and can be modified arbitrarily
559 // We use handled area offset, handled area length,
560 // handler landing pad offset and 1 (action code, gcc seems to use 0).
561 ".LLSDACSBCFA2:\n"
562 " .uleb128 .TRYSTART-__cfaehm_try_terminate\n"
563 " .uleb128 .TRYEND-.TRYSTART\n"
564 " .uleb128 .CATCH-__cfaehm_try_terminate\n"
565 " .uleb128 1\n"
566 ".LLSDACSECFA2:\n"
567 // TABLE FOOTER
568 " .text\n"
569 " .size __cfaehm_try_terminate, .-__cfaehm_try_terminate\n"
570);
571
572// Somehow this piece of helps with the resolution of debug symbols.
573__attribute__((unused)) static const int dummy = 0;
574
575asm (
576 // Add a hidden symbol which points at the function.
577 " .hidden CFA.ref.__gcfa_personality_v0\n"
578 " .weak CFA.ref.__gcfa_personality_v0\n"
579#if defined( __x86_64 ) || defined( __i386 )
580 " .align 8\n"
581#else // defined( __ARM_ARCH )
582 " .align 3\n"
583#endif
584 " .type CFA.ref.__gcfa_personality_v0, @object\n"
585 " .size CFA.ref.__gcfa_personality_v0, 8\n"
586 "CFA.ref.__gcfa_personality_v0:\n"
587#if defined( __x86_64 )
588 " .quad __gcfa_personality_v0\n"
589#elif defined( __i386 )
590 " .long __gcfa_personality_v0\n"
591#else // defined( __ARM_ARCH )
592 " .xword __gcfa_personality_v0\n"
593#endif
594);
595#else // __PIC__
596asm (
597 // HEADER
598 ".LFECFA1:\n"
599#if defined( __x86_64 ) || defined( __i386 )
600 " .globl __gcfa_personality_v0\n"
601#else // defined( __ARM_ARCH )
602 " .global __gcfa_personality_v0\n"
603#endif
604 " .section .gcc_except_table,\"a\",@progbits\n"
605 // TABLE HEADER (important field is the BODY length at the end)
606 ".LLSDACFA2:\n"
607 " .byte 0xff\n"
608 " .byte 0xff\n"
609 " .byte 0x1\n"
610 " .uleb128 .LLSDACSECFA2-.LLSDACSBCFA2\n"
611 // BODY (language specific data)
612 ".LLSDACSBCFA2:\n"
613 // Handled area start (relative to start of function)
614 " .uleb128 .TRYSTART-__cfaehm_try_terminate\n"
615 // Handled area length
616 " .uleb128 .TRYEND-.TRYSTART\n"
617 // Handler landing pad address (relative to start of function)
618 " .uleb128 .CATCH-__cfaehm_try_terminate\n"
619 // Action code, gcc seems to always use 0.
620 " .uleb128 1\n"
621 // TABLE FOOTER
622 ".LLSDACSECFA2:\n"
623 " .text\n"
624 " .size __cfaehm_try_terminate, .-__cfaehm_try_terminate\n"
625 " .ident \"GCC: (Ubuntu 6.2.0-3ubuntu11~16.04) 6.2.0 20160901\"\n"
626 " .section .note.GNU-stack,\"x\",@progbits\n"
627);
628#endif // __PIC__
629
630#pragma GCC pop_options
631
632#else
633 #error unsupported hardware architecture
634#endif // __x86_64 || __i386 || __ARM_ARCH
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