source: libcfa/src/exception.c @ c960331

arm-ehjacob/cs343-translationnew-ast-unique-expr
Last change on this file since c960331 was c960331, checked in by Andrew Beach <ajbeach@…>, 13 months ago

Attempt to clean-up the exception headers. I think this is easier to follow.

  • 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 : Andrew Beach
12// Last Modified On : Tue Oct 27 16:27:00 2020
13// Update Count     : 35
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
29#if defined( __ARM_ARCH )
30#warning FIX ME: temporary hack to keep ARM build working
31#ifndef _URC_FATAL_PHASE1_ERROR
32#define _URC_FATAL_PHASE1_ERROR 3
33#endif // ! _URC_FATAL_PHASE1_ERROR
34#ifndef _URC_FATAL_PHASE2_ERROR
35#define _URC_FATAL_PHASE2_ERROR 2
36#endif // ! _URC_FATAL_PHASE2_ERROR
37#endif // __ARM_ARCH
38
39#include "lsda.h"
40
41/* The exception class for our exceptions. Because of the vendor component
42 * its value would not be standard.
43 * Vendor: UWPL
44 * Language: CFA\0
45 */
46const _Unwind_Exception_Class __cfaehm_exception_class = 0x4c50575500414643;
47
48// Base exception vtable is abstract, you should not have base exceptions.
49struct __cfaehm_base_exception_t_vtable
50                ___cfaehm_base_exception_t_vtable_instance = {
51        .parent = NULL,
52        .size = 0,
53        .copy = NULL,
54        .free = NULL,
55        .msg = NULL
56};
57
58
59// Get the current exception context.
60// There can be a single global until multithreading occurs, then each stack
61// needs its own. We get this from libcfathreads (no weak attribute).
62__attribute__((weak)) struct exception_context_t * this_exception_context() {
63        static struct exception_context_t shared_stack = {NULL, NULL};
64        return &shared_stack;
65}
66
67
68// RESUMPTION ================================================================
69
70static void reset_top_resume(struct __cfaehm_try_resume_node ** store) {
71        this_exception_context()->top_resume = *store;
72}
73
74void __cfaehm_throw_resume(exception_t * except, void (*defaultHandler)(exception_t *)) {
75        struct exception_context_t * context = this_exception_context();
76
77        __cfadbg_print_safe(exception, "Throwing resumption exception\n");
78
79        {
80                __attribute__((cleanup(reset_top_resume)))
81                struct __cfaehm_try_resume_node * original_head = context->top_resume;
82                struct __cfaehm_try_resume_node * current = context->top_resume;
83
84                for ( ; current ; current = current->next) {
85                        context->top_resume = current->next;
86                        if (current->handler(except)) {
87                                return;
88                        }
89                }
90        } // End the search and return to the top of the stack.
91
92        // No handler found, fall back to the default operation.
93        __cfadbg_print_safe(exception, "Unhandled exception\n");
94        defaultHandler(except);
95}
96
97// Do we control where exceptions get thrown even with concurency?
98// If not these are not quite thread safe, the cleanup hook has to
99// be added after the node is built but before it is made the top node.
100
101void __cfaehm_try_resume_setup(struct __cfaehm_try_resume_node * node,
102                        _Bool (*handler)(exception_t * except)) {
103        struct exception_context_t * context = this_exception_context();
104        node->next = context->top_resume;
105        node->handler = handler;
106        context->top_resume = node;
107}
108
109void __cfaehm_try_resume_cleanup(struct __cfaehm_try_resume_node * node) {
110        struct exception_context_t * context = this_exception_context();
111        context->top_resume = node->next;
112}
113
114
115// MEMORY MANAGEMENT =========================================================
116
117#define NODE_TO_EXCEPT(node) ((exception_t *)(1 + (node)))
118#define EXCEPT_TO_NODE(except) ((struct __cfaehm_node *)(except) - 1)
119#define UNWIND_TO_NODE(unwind) ((struct __cfaehm_node *)(unwind))
120#define NULL_MAP(map, ptr) ((ptr) ? (map(ptr)) : NULL)
121
122// How to clean up an exception in various situations.
123static void __cfaehm_exception_cleanup(
124                _Unwind_Reason_Code reason,
125                struct _Unwind_Exception * exception) {
126        switch (reason) {
127        case _URC_FOREIGN_EXCEPTION_CAUGHT:
128                // This one we could clean-up to allow cross-language exceptions.
129        case _URC_FATAL_PHASE1_ERROR:
130        case _URC_FATAL_PHASE2_ERROR:
131        default:
132                abort();
133        }
134}
135
136// Creates a copy of the indicated exception and sets current_exception to it.
137static void __cfaehm_allocate_exception( exception_t * except ) {
138        struct exception_context_t * context = this_exception_context();
139
140        // Allocate memory for the exception.
141        struct __cfaehm_node * store = malloc(
142                sizeof( struct __cfaehm_node ) + except->virtual_table->size );
143
144        if ( ! store ) {
145                // Failure: cannot allocate exception. Terminate thread.
146                abort(); // <- Although I think it might be the process.
147        }
148
149        // Initialize the node:
150        exception_t * except_store = NODE_TO_EXCEPT(store);
151        store->unwind_exception.exception_class = __cfaehm_exception_class;
152        store->unwind_exception.exception_cleanup = __cfaehm_exception_cleanup;
153        store->handler_index = 0;
154        except->virtual_table->copy( except_store, except );
155
156        // Add the node to the list:
157        store->next = NULL_MAP(EXCEPT_TO_NODE, context->current_exception);
158        context->current_exception = except_store;
159}
160
161// Delete the provided exception, unsetting current_exception if relivant.
162static void __cfaehm_delete_exception( exception_t * except ) {
163        struct exception_context_t * context = this_exception_context();
164
165        __cfadbg_print_safe(exception, "Deleting Exception\n");
166
167        // Remove the exception from the list.
168        struct __cfaehm_node * to_free = EXCEPT_TO_NODE(except);
169        struct __cfaehm_node * node;
170
171        if ( context->current_exception == except ) {
172                node = to_free->next;
173                context->current_exception = NULL_MAP(NODE_TO_EXCEPT, node);
174        } else {
175                node = EXCEPT_TO_NODE(context->current_exception);
176                // It may always be in the first or second position.
177                while ( to_free != node->next ) {
178                        node = node->next;
179                }
180                node->next = to_free->next;
181        }
182
183        // Free the old exception node.
184        except->virtual_table->free( except );
185        free( to_free );
186}
187
188// CANCELLATION ==============================================================
189
190// Function needed by force unwind
191// It basically says to unwind the whole stack and then exit when we reach the end of the stack
192static _Unwind_Reason_Code _Stop_Fn(
193                int version,
194                _Unwind_Action actions,
195                _Unwind_Exception_Class exception_class,
196                struct _Unwind_Exception * unwind_exception,
197                struct _Unwind_Context * unwind_context,
198                void * stop_param) {
199        // Verify actions follow the rules we expect.
200        verify(actions & _UA_CLEANUP_PHASE);
201        verify(actions & _UA_FORCE_UNWIND);
202        verify(!(actions & _UA_SEARCH_PHASE));
203        verify(!(actions & _UA_HANDLER_FRAME));
204
205        if ( actions & _UA_END_OF_STACK ) {
206                abort();
207        } else {
208                return _URC_NO_REASON;
209        }
210}
211
212__attribute__((weak)) _Unwind_Reason_Code
213__cfaehm_cancellation_unwind( struct _Unwind_Exception * exception ) {
214        return _Unwind_ForcedUnwind( exception, _Stop_Fn, (void*)0x22 );
215}
216
217// Cancel the current stack, prefroming approprate clean-up and messaging.
218void __cfaehm_cancel_stack( exception_t * exception ) {
219        __cfaehm_allocate_exception( exception );
220
221        struct exception_context_t * context = this_exception_context();
222        struct __cfaehm_node * node = EXCEPT_TO_NODE(context->current_exception);
223
224        // Preform clean-up of any extra active exceptions.
225        while ( node->next ) {
226                struct __cfaehm_node * to_free = node->next;
227                node->next = to_free->next;
228                exception_t * except = NODE_TO_EXCEPT( to_free );
229                except->virtual_table->free( except );
230            free( to_free );
231        }
232
233        _Unwind_Reason_Code ret;
234        ret = __cfaehm_cancellation_unwind( &node->unwind_exception );
235        printf("UNWIND ERROR %d after force unwind\n", ret);
236        abort();
237}
238
239
240// TERMINATION ===============================================================
241
242// If this isn't a rethrow (*except==0), delete the provided exception.
243void __cfaehm_cleanup_terminate( void * except ) {
244        if ( *(void**)except ) __cfaehm_delete_exception( *(exception_t **)except );
245}
246
247static void __cfaehm_cleanup_default( exception_t ** except ) {
248        __cfaehm_delete_exception( *except );
249        *except = NULL;
250}
251
252// The exception that is being thrown must already be stored.
253static void __cfaehm_begin_unwind(void(*defaultHandler)(exception_t *)) {
254        struct exception_context_t * context = this_exception_context();
255        if ( NULL == context->current_exception ) {
256                printf("UNWIND ERROR missing exception in begin unwind\n");
257                abort();
258        }
259        struct _Unwind_Exception * storage =
260                &EXCEPT_TO_NODE(context->current_exception)->unwind_exception;
261
262        // Call stdlibc to raise the exception
263        __cfadbg_print_safe(exception, "Begin unwinding (storage &p, context %p)\n", storage, context);
264        _Unwind_Reason_Code ret = _Unwind_RaiseException( storage );
265
266        // If we reach here it means something happened. For resumption to work we need to find a way
267        // to return back to here. Most of them will probably boil down to setting a global flag and
268        // making the phase 1 either stop or fail. Causing an error on purpose may help avoiding
269        // unnecessary work but it might have some weird side effects. If we just pretend no handler
270        // was found that would work but may be expensive for no reason since we will always search
271        // the whole stack.
272
273        // We did not simply reach the end of the stack without finding a handler. This is an error.
274        if ( ret != _URC_END_OF_STACK ) {
275                printf("UNWIND ERROR %d after raise exception\n", ret);
276                abort();
277        }
278
279        // No handler found, go to the default operation.
280        __cfadbg_print_safe(exception, "Uncaught exception %p\n", storage);
281
282        __attribute__((cleanup(__cfaehm_cleanup_default)))
283        exception_t * exception = context->current_exception;
284        defaultHandler( exception );
285}
286
287void __cfaehm_throw_terminate( exception_t * val, void (*defaultHandler)(exception_t *) ) {
288        __cfadbg_print_safe(exception, "Throwing termination exception\n");
289
290        __cfaehm_allocate_exception( val );
291        __cfaehm_begin_unwind( defaultHandler );
292}
293
294static __attribute__((noreturn)) void __cfaehm_rethrow_adapter( exception_t * except ) {
295        // TODO: Print some error message.
296        (void)except;
297        abort();
298}
299
300void __cfaehm_rethrow_terminate(void) {
301        __cfadbg_print_safe(exception, "Rethrowing termination exception\n");
302
303        __cfaehm_begin_unwind( __cfaehm_rethrow_adapter );
304        abort();
305}
306
307#if defined( __x86_64 ) || defined( __i386 )
308// This is our personality routine. For every stack frame annotated with
309// ".cfi_personality 0x3,__gcfa_personality_v0" this function will be called twice when unwinding.
310//  Once in the search phase and once in the cleanup phase.
311_Unwind_Reason_Code __gcfa_personality_v0(
312                int version,
313                _Unwind_Action actions,
314                unsigned long long exception_class,
315                struct _Unwind_Exception * unwind_exception,
316                struct _Unwind_Context * unwind_context)
317{
318
319        //__cfadbg_print_safe(exception, "CFA: 0x%lx\n", _Unwind_GetCFA(context));
320        __cfadbg_print_safe(exception, "Personality function (%d, %x, %llu, %p, %p):",
321                        version, actions, exception_class, unwind_exception, unwind_context);
322
323        // Verify that actions follow the rules we expect.
324        // This function should never be called at the end of the stack.
325        verify(!(actions & _UA_END_OF_STACK));
326        // Either only the search phase flag is set or...
327        if (actions & _UA_SEARCH_PHASE) {
328                verify(actions == _UA_SEARCH_PHASE);
329                __cfadbg_print_safe(exception, " lookup phase");
330        // ... we are in clean-up phase.
331        } else {
332                verify(actions & _UA_CLEANUP_PHASE);
333                __cfadbg_print_safe(exception, " cleanup phase");
334                // We shouldn't be the handler frame during forced unwind.
335                if (actions & _UA_HANDLER_FRAME) {
336                        verify(!(actions & _UA_FORCE_UNWIND));
337                        __cfadbg_print_safe(exception, " (handler frame)");
338                } else if (actions & _UA_FORCE_UNWIND) {
339                        __cfadbg_print_safe(exception, " (force unwind)");
340                }
341        }
342
343        // Get a pointer to the language specific data from which we will read what we need
344        const unsigned char * lsd = _Unwind_GetLanguageSpecificData( unwind_context );
345
346        if ( !lsd ) {   //Nothing to do, keep unwinding
347                printf(" no LSD");
348                goto UNWIND;
349        }
350
351        // Get the instuction pointer and a reading pointer into the exception table
352        lsda_header_info lsd_info;
353        const unsigned char * cur_ptr = parse_lsda_header(unwind_context, lsd, &lsd_info);
354        _Unwind_Ptr instruction_ptr = _Unwind_GetIP(unwind_context);
355
356        struct exception_context_t * context = this_exception_context();
357
358        // Linearly search the table for stuff to do
359        while ( cur_ptr < lsd_info.action_table ) {
360                _Unwind_Ptr callsite_start;
361                _Unwind_Ptr callsite_len;
362                _Unwind_Ptr callsite_landing_pad;
363                _uleb128_t  callsite_action;
364
365                // Decode the common stuff we have in here
366                cur_ptr = read_encoded_value(0, lsd_info.call_site_encoding, cur_ptr, &callsite_start);
367                cur_ptr = read_encoded_value(0, lsd_info.call_site_encoding, cur_ptr, &callsite_len);
368                cur_ptr = read_encoded_value(0, lsd_info.call_site_encoding, cur_ptr, &callsite_landing_pad);
369                cur_ptr = read_uleb128(cur_ptr, &callsite_action);
370
371                // Have we reach the correct frame info yet?
372                if ( lsd_info.Start + callsite_start + callsite_len < instruction_ptr ) {
373#ifdef __CFA_DEBUG_PRINT__
374                        void * ls = (void*)lsd_info.Start;
375                        void * cs = (void*)callsite_start;
376                        void * cl = (void*)callsite_len;
377                        void * bp = (void*)lsd_info.Start + callsite_start;
378                        void * ep = (void*)lsd_info.Start + callsite_start + callsite_len;
379                        void * ip = (void*)instruction_ptr;
380                        __cfadbg_print_safe(exception, "\nfound %p - %p (%p, %p, %p), looking for %p\n",
381                                        bp, ep, ls, cs, cl, ip);
382#endif // __CFA_DEBUG_PRINT__
383                        continue;
384                }
385
386                // Have we gone too far?
387                if ( lsd_info.Start + callsite_start > instruction_ptr ) {
388                        printf(" gone too far");
389                        break;
390                }
391
392                // Check for what we must do:
393                if ( 0 == callsite_landing_pad ) {
394                        // Nothing to do, move along
395                        __cfadbg_print_safe(exception, " no landing pad");
396                } else if (actions & _UA_SEARCH_PHASE) {
397                        // In search phase, these means we found a potential handler we must check.
398
399                        // We have arbitrarily decided that 0 means nothing to do and 1 means there is
400                        // a potential handler. This doesn't seem to conflict the gcc default behavior.
401                        if (callsite_action != 0) {
402                                // Now we want to run some code to see if the handler matches
403                                // This is the tricky part where we want to the power to run arbitrary code
404                                // However, generating a new exception table entry and try routine every time
405                                // is way more expansive than we might like
406                                // The information we have is :
407                                //  - The GR (Series of registers)
408                                //    GR1=GP Global Pointer of frame ref by context
409                                //  - The instruction pointer
410                                //  - The instruction pointer info (???)
411                                //  - The CFA (Canonical Frame Address)
412                                //  - The BSP (Probably the base stack pointer)
413
414                                // The current apprach uses one exception table entry per try block
415                                _uleb128_t imatcher;
416                                // Get the relative offset to the {...}?
417                                cur_ptr = read_uleb128(cur_ptr, &imatcher);
418
419                                _Unwind_Word match_pos =
420#                               if defined( __x86_64 )
421                                    _Unwind_GetCFA(unwind_context) + 8;
422#                               elif defined( __i386 )
423                                    _Unwind_GetCFA(unwind_context) + 24;
424#                               elif defined( __ARM_ARCH )
425#                                   warning FIX ME: check if anything needed for ARM
426                                    42;
427#                               endif
428                                int (*matcher)(exception_t *) = *(int(**)(exception_t *))match_pos;
429
430                                int index = matcher(context->current_exception);
431                                _Unwind_Reason_Code ret = (0 == index)
432                                        ? _URC_CONTINUE_UNWIND : _URC_HANDLER_FOUND;
433                                UNWIND_TO_NODE(unwind_exception)->handler_index = index;
434
435                                // Based on the return value, check if we matched the exception
436                                if (ret == _URC_HANDLER_FOUND) {
437                                        __cfadbg_print_safe(exception, " handler found\n");
438                                } else {
439                                        // TODO: Continue the search if there is more in the table.
440                                        __cfadbg_print_safe(exception, " no handler\n");
441                                }
442                                return ret;
443                        }
444
445                        // This is only a cleanup handler, ignore it
446                        __cfadbg_print_safe(exception, " no action");
447                } else {
448                        // In clean-up phase, no destructors here but this could be the handler.
449
450                        if ( (callsite_action != 0) && !(actions & _UA_HANDLER_FRAME) ){
451                                // If this is a potential exception handler
452                                // but not the one that matched the exception in the seach phase,
453                                // just ignore it
454                                goto UNWIND;
455                        }
456
457                        // We need to run some clean-up or a handler
458                        // These statment do the right thing but I don't know any specifics at all
459                        _Unwind_SetGR( unwind_context, __builtin_eh_return_data_regno(0),
460                                (_Unwind_Ptr)unwind_exception );
461                        _Unwind_SetGR( unwind_context, __builtin_eh_return_data_regno(1), 0 );
462
463                        // I assume this sets the instruction pointer to the adress of the landing pad
464                        // It doesn't actually set it, it only state the value that needs to be set once we
465                        // return _URC_INSTALL_CONTEXT
466                        _Unwind_SetIP( unwind_context, ((lsd_info.LPStart) + (callsite_landing_pad)) );
467
468                        __cfadbg_print_safe(exception, " action\n");
469
470                        // Return have some action to run
471                        return _URC_INSTALL_CONTEXT;
472                }
473        }
474        // No handling found
475        __cfadbg_print_safe(exception, " table end reached");
476
477        UNWIND:
478        __cfadbg_print_safe(exception, " unwind\n");
479
480        // Keep unwinding the stack
481        return _URC_CONTINUE_UNWIND;
482}
483
484#pragma GCC push_options
485#pragma GCC optimize(0)
486
487// Try statements are hoisted out see comments for details. While this could probably be unique
488// and simply linked from libcfa but there is one problem left, see the exception table for details
489__attribute__((noinline))
490void __cfaehm_try_terminate(void (*try_block)(),
491                void (*catch_block)(int index, exception_t * except),
492                __attribute__((unused)) int (*match_block)(exception_t * except)) {
493        //! volatile int xy = 0;
494        //! printf("%p %p %p %p\n", &try_block, &catch_block, &match_block, &xy);
495
496        // Setup the personality routine and exception table.
497        // Unforturnately these clobber gcc cancellation support which means we can't get access to
498        // the attribute cleanup tables at the same time. We would have to inspect the assembly to
499        // create a new set ourselves.
500#ifdef __PIC__
501        asm volatile (".cfi_personality 0x9b,CFA.ref.__gcfa_personality_v0");
502        asm volatile (".cfi_lsda 0x1b, .LLSDACFA2");
503#else
504        asm volatile (".cfi_personality 0x3,__gcfa_personality_v0");
505        asm volatile (".cfi_lsda 0x3, .LLSDACFA2");
506#endif
507
508        // Label which defines the start of the area for which the handler is setup.
509        asm volatile (".TRYSTART:");
510
511        // The actual statements of the try blocks
512        try_block();
513
514        // asm statement to prevent deadcode removal
515        asm volatile goto ("" : : : : CATCH );
516
517        // Normal return for when there is no throw.
518        return;
519
520        // Exceptionnal path
521        CATCH : __attribute__(( unused ));
522        // Label which defines the end of the area for which the handler is setup.
523        asm volatile (".TRYEND:");
524        // Label which defines the start of the exception landing pad. Basically what is called when
525        // the exception is caught. Note, if multiple handlers are given, the multiplexing should be
526        // done by the generated code, not the exception runtime.
527        asm volatile (".CATCH:");
528
529        // Exception handler
530        // Note: Saving the exception context on the stack breaks termination exceptions.
531        catch_block( EXCEPT_TO_NODE( this_exception_context()->current_exception )->handler_index,
532                     this_exception_context()->current_exception );
533}
534
535// Exception table data we need to generate. While this is almost generic, the custom data refers
536// to {*}try_terminate, which is no way generic. Some more works need to be done if we want to
537// have a single call to the try routine.
538
539#ifdef __PIC__
540asm (
541        // HEADER
542        ".LFECFA1:\n"
543        "       .globl  __gcfa_personality_v0\n"
544        "       .section        .gcc_except_table,\"a\",@progbits\n"
545        // TABLE HEADER (important field is the BODY length at the end)
546        ".LLSDACFA2:\n"
547        "       .byte   0xff\n"
548        "       .byte   0xff\n"
549        "       .byte   0x1\n"
550        "       .uleb128 .LLSDACSECFA2-.LLSDACSBCFA2\n"
551        // BODY (language specific data)
552        // This uses language specific data and can be modified arbitrarily
553        // We use handled area offset, handled area length,
554        // handler landing pad offset and 1 (action code, gcc seems to use 0).
555        ".LLSDACSBCFA2:\n"
556        "       .uleb128 .TRYSTART-__cfaehm_try_terminate\n"
557        "       .uleb128 .TRYEND-.TRYSTART\n"
558        "       .uleb128 .CATCH-__cfaehm_try_terminate\n"
559        "       .uleb128 1\n"
560        ".LLSDACSECFA2:\n"
561        // TABLE FOOTER
562        "       .text\n"
563        "       .size   __cfaehm_try_terminate, .-__cfaehm_try_terminate\n"
564);
565
566// Somehow this piece of helps with the resolution of debug symbols.
567__attribute__((unused)) static const int dummy = 0;
568
569asm (
570        // Add a hidden symbol which points at the function.
571        "       .hidden CFA.ref.__gcfa_personality_v0\n"
572        "       .weak   CFA.ref.__gcfa_personality_v0\n"
573        // No clue what this does specifically
574        "       .section        .data.rel.local.CFA.ref.__gcfa_personality_v0,\"awG\",@progbits,CFA.ref.__gcfa_personality_v0,comdat\n"
575        "       .align 8\n"
576        "       .type CFA.ref.__gcfa_personality_v0, @object\n"
577        "       .size CFA.ref.__gcfa_personality_v0, 8\n"
578        "CFA.ref.__gcfa_personality_v0:\n"
579#if defined( __x86_64 )
580        "       .quad __gcfa_personality_v0\n"
581#else // then __i386
582        "       .long __gcfa_personality_v0\n"
583#endif
584);
585#else // __PIC__
586asm (
587        // HEADER
588        ".LFECFA1:\n"
589        "       .globl  __gcfa_personality_v0\n"
590        "       .section        .gcc_except_table,\"a\",@progbits\n"
591        // TABLE HEADER (important field is the BODY length at the end)
592        ".LLSDACFA2:\n"
593        "       .byte   0xff\n"
594        "       .byte   0xff\n"
595        "       .byte   0x1\n"
596        "       .uleb128 .LLSDACSECFA2-.LLSDACSBCFA2\n"
597        // BODY (language specific data)
598        ".LLSDACSBCFA2:\n"
599        //      Handled area start (relative to start of function)
600        "       .uleb128 .TRYSTART-__cfaehm_try_terminate\n"
601        //      Handled area length
602        "       .uleb128 .TRYEND-.TRYSTART\n"
603        //      Handler landing pad address (relative to start of function)
604        "       .uleb128 .CATCH-__cfaehm_try_terminate\n"
605        //      Action code, gcc seems to always use 0.
606        "       .uleb128 1\n"
607        // TABLE FOOTER
608        ".LLSDACSECFA2:\n"
609        "       .text\n"
610        "       .size   __cfaehm_try_terminate, .-__cfaehm_try_terminate\n"
611        "       .ident  \"GCC: (Ubuntu 6.2.0-3ubuntu11~16.04) 6.2.0 20160901\"\n"
612        "       .section        .note.GNU-stack,\"x\",@progbits\n"
613);
614#endif // __PIC__
615
616#pragma GCC pop_options
617
618#elif defined( __ARM_ARCH )
619_Unwind_Reason_Code __gcfa_personality_v0(
620                int version,
621                _Unwind_Action actions,
622                unsigned long long exception_class,
623                struct _Unwind_Exception * unwind_exception,
624                struct _Unwind_Context * unwind_context) {
625        return _URC_CONTINUE_UNWIND;
626}
627
628__attribute__((noinline))
629void __cfaehm_try_terminate(void (*try_block)(),
630                void (*catch_block)(int index, exception_t * except),
631                __attribute__((unused)) int (*match_block)(exception_t * except)) {
632}
633#else
634        #error unsupported hardware architecture
635#endif // __x86_64 || __i386
Note: See TracBrowser for help on using the repository browser.