diff options
Diffstat (limited to 'gcc-4.8.1/libgo/runtime/go-unwind.c')
| -rw-r--r-- | gcc-4.8.1/libgo/runtime/go-unwind.c | 440 |
1 files changed, 0 insertions, 440 deletions
diff --git a/gcc-4.8.1/libgo/runtime/go-unwind.c b/gcc-4.8.1/libgo/runtime/go-unwind.c deleted file mode 100644 index c669a3ce8..000000000 --- a/gcc-4.8.1/libgo/runtime/go-unwind.c +++ /dev/null @@ -1,440 +0,0 @@ -/* go-unwind.c -- unwind the stack for panic/recover. - - Copyright 2010 The Go Authors. All rights reserved. - Use of this source code is governed by a BSD-style - license that can be found in the LICENSE file. */ - -#include "config.h" - -#include <stdlib.h> -#include <unistd.h> - -#include "unwind.h" -#define NO_SIZE_OF_ENCODED_VALUE -#include "unwind-pe.h" - -#include "runtime.h" -#include "go-alloc.h" -#include "go-defer.h" -#include "go-panic.h" - -/* The code for a Go exception. */ - -#ifdef __ARM_EABI_UNWINDER__ -static const _Unwind_Exception_Class __go_exception_class = - { 'G', 'N', 'U', 'C', 'G', 'O', '\0', '\0' }; -#else -static const _Unwind_Exception_Class __go_exception_class = - ((((((((_Unwind_Exception_Class) 'G' - << 8 | (_Unwind_Exception_Class) 'N') - << 8 | (_Unwind_Exception_Class) 'U') - << 8 | (_Unwind_Exception_Class) 'C') - << 8 | (_Unwind_Exception_Class) 'G') - << 8 | (_Unwind_Exception_Class) 'O') - << 8 | (_Unwind_Exception_Class) '\0') - << 8 | (_Unwind_Exception_Class) '\0'); -#endif - - -/* This function is called by exception handlers used when unwinding - the stack after a recovered panic. The exception handler looks - like this: - __go_check_defer (frame); - return; - If we have not yet reached the frame we are looking for, we - continue unwinding. */ - -void -__go_check_defer (_Bool *frame) -{ - G *g; - struct _Unwind_Exception *hdr; - - g = runtime_g (); - - if (g == NULL) - { - /* Some other language has thrown an exception. We know there - are no defer handlers, so there is nothing to do. */ - } - else if (g->is_foreign) - { - struct __go_panic_stack *n; - _Bool was_recovered; - - /* Some other language has thrown an exception. We need to run - the local defer handlers. If they call recover, we stop - unwinding the stack here. */ - - n = ((struct __go_panic_stack *) - __go_alloc (sizeof (struct __go_panic_stack))); - - n->__arg.__type_descriptor = NULL; - n->__arg.__object = NULL; - n->__was_recovered = 0; - n->__is_foreign = 1; - n->__next = g->panic; - g->panic = n; - - while (1) - { - struct __go_defer_stack *d; - void (*pfn) (void *); - - d = g->defer; - if (d == NULL || d->__frame != frame || d->__pfn == NULL) - break; - - pfn = d->__pfn; - g->defer = d->__next; - - (*pfn) (d->__arg); - - __go_free (d); - - if (n->__was_recovered) - { - /* The recover function caught the panic thrown by some - other language. */ - break; - } - } - - was_recovered = n->__was_recovered; - g->panic = n->__next; - __go_free (n); - - if (was_recovered) - { - /* Just return and continue executing Go code. */ - *frame = 1; - return; - } - - /* We are panicing through this function. */ - *frame = 0; - } - else if (g->defer != NULL - && g->defer->__pfn == NULL - && g->defer->__frame == frame) - { - struct __go_defer_stack *d; - - /* This is the defer function which called recover. Simply - return to stop the stack unwind, and let the Go code continue - to execute. */ - d = g->defer; - g->defer = d->__next; - __go_free (d); - - /* We are returning from this function. */ - *frame = 1; - - return; - } - - /* This is some other defer function. It was already run by the - call to panic, or just above. Rethrow the exception. */ - - hdr = (struct _Unwind_Exception *) g->exception; - -#ifdef LIBGO_SJLJ_EXCEPTIONS - _Unwind_SjLj_Resume_or_Rethrow (hdr); -#else -#if defined(_LIBUNWIND_STD_ABI) - _Unwind_RaiseException (hdr); -#else - _Unwind_Resume_or_Rethrow (hdr); -#endif -#endif - - /* Rethrowing the exception should not return. */ - abort(); -} - -/* Unwind function calls until we reach the one which used a defer - function which called recover. Each function which uses a defer - statement will have an exception handler, as shown above. */ - -void -__go_unwind_stack () -{ - struct _Unwind_Exception *hdr; - - hdr = ((struct _Unwind_Exception *) - __go_alloc (sizeof (struct _Unwind_Exception))); - __builtin_memcpy (&hdr->exception_class, &__go_exception_class, - sizeof hdr->exception_class); - hdr->exception_cleanup = NULL; - - runtime_g ()->exception = hdr; - -#ifdef __USING_SJLJ_EXCEPTIONS__ - _Unwind_SjLj_RaiseException (hdr); -#else - _Unwind_RaiseException (hdr); -#endif - - /* Raising an exception should not return. */ - abort (); -} - -/* The rest of this code is really similar to gcc/unwind-c.c and - libjava/exception.cc. */ - -typedef struct -{ - _Unwind_Ptr Start; - _Unwind_Ptr LPStart; - _Unwind_Ptr ttype_base; - const unsigned char *TType; - const unsigned char *action_table; - unsigned char ttype_encoding; - unsigned char call_site_encoding; -} lsda_header_info; - -static const unsigned char * -parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p, - lsda_header_info *info) -{ - _uleb128_t tmp; - unsigned char lpstart_encoding; - - info->Start = (context ? _Unwind_GetRegionStart (context) : 0); - - /* Find @LPStart, the base to which landing pad offsets are relative. */ - lpstart_encoding = *p++; - if (lpstart_encoding != DW_EH_PE_omit) - p = read_encoded_value (context, lpstart_encoding, p, &info->LPStart); - else - info->LPStart = info->Start; - - /* Find @TType, the base of the handler and exception spec type data. */ - info->ttype_encoding = *p++; - if (info->ttype_encoding != DW_EH_PE_omit) - { - p = read_uleb128 (p, &tmp); - info->TType = p + tmp; - } - else - info->TType = 0; - - /* The encoding and length of the call-site table; the action table - immediately follows. */ - info->call_site_encoding = *p++; - p = read_uleb128 (p, &tmp); - info->action_table = p + tmp; - - return p; -} - -/* The personality function is invoked when unwinding the stack due to - a panic. Its job is to find the cleanup and exception handlers to - run. We can't split the stack here, because we won't be able to - unwind from that split. */ - -#ifdef __ARM_EABI_UNWINDER__ -/* ARM EABI personality routines must also unwind the stack. */ -#define CONTINUE_UNWINDING \ - do \ - { \ - if (__gnu_unwind_frame (ue_header, context) != _URC_OK) \ - return _URC_FAILURE; \ - return _URC_CONTINUE_UNWIND; \ - } \ - while (0) -#else -#define CONTINUE_UNWINDING return _URC_CONTINUE_UNWIND -#endif - -#ifdef __USING_SJLJ_EXCEPTIONS__ -#define PERSONALITY_FUNCTION __gccgo_personality_sj0 -#define __builtin_eh_return_data_regno(x) x -#else -#define PERSONALITY_FUNCTION __gccgo_personality_v0 -#endif - -#ifdef __ARM_EABI_UNWINDER__ -_Unwind_Reason_Code -PERSONALITY_FUNCTION (_Unwind_State, struct _Unwind_Exception *, - struct _Unwind_Context *) - __attribute__ ((no_split_stack, flatten)); - -_Unwind_Reason_Code -PERSONALITY_FUNCTION (_Unwind_State state, - struct _Unwind_Exception * ue_header, - struct _Unwind_Context * context) -#else -_Unwind_Reason_Code -PERSONALITY_FUNCTION (int, _Unwind_Action, _Unwind_Exception_Class, - struct _Unwind_Exception *, struct _Unwind_Context *) - __attribute__ ((no_split_stack, flatten)); - -_Unwind_Reason_Code -PERSONALITY_FUNCTION (int version, - _Unwind_Action actions, - _Unwind_Exception_Class exception_class, - struct _Unwind_Exception *ue_header, - struct _Unwind_Context *context) -#endif -{ - lsda_header_info info; - const unsigned char *language_specific_data, *p, *action_record; - _Unwind_Ptr landing_pad, ip; - int ip_before_insn = 0; - _Bool is_foreign; - G *g; - -#ifdef __ARM_EABI_UNWINDER__ - _Unwind_Action actions; - - switch (state & _US_ACTION_MASK) - { - case _US_VIRTUAL_UNWIND_FRAME: - actions = _UA_SEARCH_PHASE; - break; - - case _US_UNWIND_FRAME_STARTING: - actions = _UA_CLEANUP_PHASE; - if (!(state & _US_FORCE_UNWIND) - && ue_header->barrier_cache.sp == _Unwind_GetGR(context, 13)) - actions |= _UA_HANDLER_FRAME; - break; - - case _US_UNWIND_FRAME_RESUME: - CONTINUE_UNWINDING; - break; - - default: - abort(); - } - actions |= state & _US_FORCE_UNWIND; - - is_foreign = 0; - - /* The dwarf unwinder assumes the context structure holds things like the - function and LSDA pointers. The ARM implementation caches these in - the exception header (UCB). To avoid rewriting everything we make the - virtual IP register point at the UCB. */ - ip = (_Unwind_Ptr) ue_header; - _Unwind_SetGR (context, 12, ip); -#else - if (version != 1) - return _URC_FATAL_PHASE1_ERROR; - - is_foreign = exception_class != __go_exception_class; -#endif - - language_specific_data = (const unsigned char *) - _Unwind_GetLanguageSpecificData (context); - - /* If no LSDA, then there are no handlers or cleanups. */ - if (! language_specific_data) - CONTINUE_UNWINDING; - - /* Parse the LSDA header. */ - p = parse_lsda_header (context, language_specific_data, &info); -#ifdef HAVE_GETIPINFO - ip = _Unwind_GetIPInfo (context, &ip_before_insn); -#else - ip = _Unwind_GetIP (context); -#endif - if (! ip_before_insn) - --ip; - landing_pad = 0; - action_record = NULL; - -#ifdef __USING_SJLJ_EXCEPTIONS__ - /* The given "IP" is an index into the call-site table, with two - exceptions -- -1 means no-action, and 0 means terminate. But - since we're using uleb128 values, we've not got random access - to the array. */ - if ((int) ip <= 0) - return _URC_CONTINUE_UNWIND; - else - { - _uleb128_t cs_lp, cs_action; - do - { - p = read_uleb128 (p, &cs_lp); - p = read_uleb128 (p, &cs_action); - } - while (--ip); - - /* Can never have null landing pad for sjlj -- that would have - been indicated by a -1 call site index. */ - landing_pad = (_Unwind_Ptr)cs_lp + 1; - if (cs_action) - action_record = info.action_table + cs_action - 1; - goto found_something; - } -#else - /* Search the call-site table for the action associated with this IP. */ - while (p < info.action_table) - { - _Unwind_Ptr cs_start, cs_len, cs_lp; - _uleb128_t cs_action; - - /* Note that all call-site encodings are "absolute" displacements. */ - p = read_encoded_value (0, info.call_site_encoding, p, &cs_start); - p = read_encoded_value (0, info.call_site_encoding, p, &cs_len); - p = read_encoded_value (0, info.call_site_encoding, p, &cs_lp); - p = read_uleb128 (p, &cs_action); - - /* The table is sorted, so if we've passed the ip, stop. */ - if (ip < info.Start + cs_start) - p = info.action_table; - else if (ip < info.Start + cs_start + cs_len) - { - if (cs_lp) - landing_pad = info.LPStart + cs_lp; - if (cs_action) - action_record = info.action_table + cs_action - 1; - goto found_something; - } - } -#endif - - /* IP is not in table. No associated cleanups. */ - CONTINUE_UNWINDING; - - found_something: - if (landing_pad == 0) - { - /* IP is present, but has a null landing pad. - No handler to be run. */ - CONTINUE_UNWINDING; - } - - if (actions & _UA_SEARCH_PHASE) - { - if (action_record == 0) - { - /* This indicates a cleanup rather than an exception - handler. */ - CONTINUE_UNWINDING; - } - - return _URC_HANDLER_FOUND; - } - - /* It's possible for g to be NULL here for an exception thrown by a - language other than Go. */ - g = runtime_g (); - if (g == NULL) - { - if (!is_foreign) - abort (); - } - else - { - g->exception = ue_header; - g->is_foreign = is_foreign; - } - - _Unwind_SetGR (context, __builtin_eh_return_data_regno (0), - (_Unwind_Ptr) ue_header); - _Unwind_SetGR (context, __builtin_eh_return_data_regno (1), 0); - _Unwind_SetIP (context, landing_pad); - return _URC_INSTALL_CONTEXT; -} |