1720 lines
46 KiB
C
1720 lines
46 KiB
C
/* DWARF2 exception handling and frame unwind runtime interface routines.
|
||
Copyright (C) 1997-2014 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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||
the Free Software Foundation; either version 3, or (at your option)
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||
any later version.
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||
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||
GCC is distributed in the hope that it will be useful, but WITHOUT
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||
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
||
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
|
||
License for more details.
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||
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||
Under Section 7 of GPL version 3, you are granted additional
|
||
permissions described in the GCC Runtime Library Exception, version
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||
3.1, as published by the Free Software Foundation.
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||
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||
You should have received a copy of the GNU General Public License and
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||
a copy of the GCC Runtime Library Exception along with this program;
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||
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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||
<http://www.gnu.org/licenses/>. */
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||
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#include "tconfig.h"
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||
#include "tsystem.h"
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||
#include "coretypes.h"
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||
#include "tm.h"
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||
#include "libgcc_tm.h"
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||
#include "dwarf2.h"
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||
#include "unwind.h"
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#ifdef __USING_SJLJ_EXCEPTIONS__
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# define NO_SIZE_OF_ENCODED_VALUE
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#endif
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#include "unwind-pe.h"
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||
#include "unwind-dw2-fde.h"
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#include "gthr.h"
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#include "unwind-dw2.h"
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#ifdef HAVE_SYS_SDT_H
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#include <sys/sdt.h>
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#endif
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#ifndef __USING_SJLJ_EXCEPTIONS__
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||
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#ifndef STACK_GROWS_DOWNWARD
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#define STACK_GROWS_DOWNWARD 0
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#else
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#undef STACK_GROWS_DOWNWARD
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#define STACK_GROWS_DOWNWARD 1
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#endif
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/* Dwarf frame registers used for pre gcc 3.0 compiled glibc. */
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#ifndef PRE_GCC3_DWARF_FRAME_REGISTERS
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#define PRE_GCC3_DWARF_FRAME_REGISTERS DWARF_FRAME_REGISTERS
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#endif
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#ifndef DWARF_REG_TO_UNWIND_COLUMN
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#define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO)
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#endif
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/* ??? For the public function interfaces, we tend to gcc_assert that the
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column numbers are in range. For the dwarf2 unwind info this does happen,
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although so far in a case that doesn't actually matter.
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See PR49146, in which a call from x86_64 ms abi to x86_64 unix abi stores
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the call-saved xmm registers and annotates them. We havn't bothered
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providing support for the xmm registers for the x86_64 port primarily
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because the 64-bit windows targets don't use dwarf2 unwind, using sjlj or
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SEH instead. Adding the support for unix targets would generally be a
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waste. However, some runtime libraries supplied with ICC do contain such
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an unorthodox transition, as well as the unwind info to match. This loss
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of register restoration doesn't matter in practice, because the exception
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is caught in the native unix abi, where all of the xmm registers are
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call clobbered.
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Ideally, we'd record some bit to notice when we're failing to restore some
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register recorded in the unwind info, but to do that we need annotation on
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the unix->ms abi edge, so that we know when the register data may be
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discarded. And since this edge is also within the ICC library, we're
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unlikely to be able to get the new annotation.
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Barring a magic solution to restore the ms abi defined 128-bit xmm registers
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(as distictly opposed to the full runtime width) without causing extra
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overhead for normal unix abis, the best solution seems to be to simply
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ignore unwind data for unknown columns. */
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#define UNWIND_COLUMN_IN_RANGE(x) \
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__builtin_expect((x) <= DWARF_FRAME_REGISTERS, 1)
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#ifdef REG_VALUE_IN_UNWIND_CONTEXT
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typedef _Unwind_Word _Unwind_Context_Reg_Val;
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#ifndef ASSUME_EXTENDED_UNWIND_CONTEXT
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#define ASSUME_EXTENDED_UNWIND_CONTEXT 1
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#endif
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static inline _Unwind_Word
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_Unwind_Get_Unwind_Word (_Unwind_Context_Reg_Val val)
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{
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return val;
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}
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static inline _Unwind_Context_Reg_Val
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_Unwind_Get_Unwind_Context_Reg_Val (_Unwind_Word val)
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{
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return val;
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}
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#else
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typedef void *_Unwind_Context_Reg_Val;
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static inline _Unwind_Word
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_Unwind_Get_Unwind_Word (_Unwind_Context_Reg_Val val)
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||
{
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return (_Unwind_Word) (_Unwind_Internal_Ptr) val;
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}
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static inline _Unwind_Context_Reg_Val
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_Unwind_Get_Unwind_Context_Reg_Val (_Unwind_Word val)
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{
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return (_Unwind_Context_Reg_Val) (_Unwind_Internal_Ptr) val;
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}
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#endif
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#ifndef ASSUME_EXTENDED_UNWIND_CONTEXT
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#define ASSUME_EXTENDED_UNWIND_CONTEXT 0
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#endif
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/* This is the register and unwind state for a particular frame. This
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provides the information necessary to unwind up past a frame and return
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to its caller. */
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struct _Unwind_Context
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||
{
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_Unwind_Context_Reg_Val reg[DWARF_FRAME_REGISTERS+1];
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void *cfa;
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void *ra;
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void *lsda;
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struct dwarf_eh_bases bases;
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/* Signal frame context. */
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#define SIGNAL_FRAME_BIT ((~(_Unwind_Word) 0 >> 1) + 1)
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/* Context which has version/args_size/by_value fields. */
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#define EXTENDED_CONTEXT_BIT ((~(_Unwind_Word) 0 >> 2) + 1)
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_Unwind_Word flags;
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||
/* 0 for now, can be increased when further fields are added to
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struct _Unwind_Context. */
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_Unwind_Word version;
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||
_Unwind_Word args_size;
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char by_value[DWARF_FRAME_REGISTERS+1];
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};
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/* Byte size of every register managed by these routines. */
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static unsigned char dwarf_reg_size_table[DWARF_FRAME_REGISTERS+1];
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/* Read unaligned data from the instruction buffer. */
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union unaligned
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{
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void *p;
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unsigned u2 __attribute__ ((mode (HI)));
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unsigned u4 __attribute__ ((mode (SI)));
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unsigned u8 __attribute__ ((mode (DI)));
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signed s2 __attribute__ ((mode (HI)));
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signed s4 __attribute__ ((mode (SI)));
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signed s8 __attribute__ ((mode (DI)));
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} __attribute__ ((packed));
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static void uw_update_context (struct _Unwind_Context *, _Unwind_FrameState *);
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static _Unwind_Reason_Code uw_frame_state_for (struct _Unwind_Context *,
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_Unwind_FrameState *);
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static inline void *
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read_pointer (const void *p) { const union unaligned *up = p; return up->p; }
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static inline int
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read_1u (const void *p) { return *(const unsigned char *) p; }
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static inline int
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read_1s (const void *p) { return *(const signed char *) p; }
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static inline int
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read_2u (const void *p) { const union unaligned *up = p; return up->u2; }
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static inline int
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read_2s (const void *p) { const union unaligned *up = p; return up->s2; }
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static inline unsigned int
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read_4u (const void *p) { const union unaligned *up = p; return up->u4; }
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static inline int
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read_4s (const void *p) { const union unaligned *up = p; return up->s4; }
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static inline unsigned long
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||
read_8u (const void *p) { const union unaligned *up = p; return up->u8; }
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static inline unsigned long
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read_8s (const void *p) { const union unaligned *up = p; return up->s8; }
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static inline _Unwind_Word
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_Unwind_IsSignalFrame (struct _Unwind_Context *context)
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{
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return (context->flags & SIGNAL_FRAME_BIT) ? 1 : 0;
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}
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static inline void
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_Unwind_SetSignalFrame (struct _Unwind_Context *context, int val)
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{
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if (val)
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context->flags |= SIGNAL_FRAME_BIT;
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else
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context->flags &= ~SIGNAL_FRAME_BIT;
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}
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static inline _Unwind_Word
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_Unwind_IsExtendedContext (struct _Unwind_Context *context)
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{
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return (ASSUME_EXTENDED_UNWIND_CONTEXT
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|| (context->flags & EXTENDED_CONTEXT_BIT));
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}
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/* Get the value of register INDEX as saved in CONTEXT. */
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inline _Unwind_Word
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_Unwind_GetGR (struct _Unwind_Context *context, int index)
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{
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int size;
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_Unwind_Context_Reg_Val val;
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#ifdef DWARF_ZERO_REG
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if (index == DWARF_ZERO_REG)
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return 0;
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#endif
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index = DWARF_REG_TO_UNWIND_COLUMN (index);
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gcc_assert (index < (int) sizeof(dwarf_reg_size_table));
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size = dwarf_reg_size_table[index];
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val = context->reg[index];
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if (_Unwind_IsExtendedContext (context) && context->by_value[index])
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return _Unwind_Get_Unwind_Word (val);
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/* This will segfault if the register hasn't been saved. */
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if (size == sizeof(_Unwind_Ptr))
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return * (_Unwind_Ptr *) (_Unwind_Internal_Ptr) val;
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else
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{
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gcc_assert (size == sizeof(_Unwind_Word));
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return * (_Unwind_Word *) (_Unwind_Internal_Ptr) val;
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}
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}
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static inline void *
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_Unwind_GetPtr (struct _Unwind_Context *context, int index)
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{
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return (void *)(_Unwind_Ptr) _Unwind_GetGR (context, index);
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}
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/* Get the value of the CFA as saved in CONTEXT. */
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_Unwind_Word
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_Unwind_GetCFA (struct _Unwind_Context *context)
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{
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return (_Unwind_Ptr) context->cfa;
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}
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/* Overwrite the saved value for register INDEX in CONTEXT with VAL. */
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inline void
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_Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val)
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{
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int size;
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void *ptr;
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index = DWARF_REG_TO_UNWIND_COLUMN (index);
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gcc_assert (index < (int) sizeof(dwarf_reg_size_table));
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size = dwarf_reg_size_table[index];
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if (_Unwind_IsExtendedContext (context) && context->by_value[index])
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{
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context->reg[index] = _Unwind_Get_Unwind_Context_Reg_Val (val);
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return;
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}
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ptr = (void *) (_Unwind_Internal_Ptr) context->reg[index];
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if (size == sizeof(_Unwind_Ptr))
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* (_Unwind_Ptr *) ptr = val;
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else
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{
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gcc_assert (size == sizeof(_Unwind_Word));
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* (_Unwind_Word *) ptr = val;
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}
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}
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/* Get the pointer to a register INDEX as saved in CONTEXT. */
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static inline void *
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_Unwind_GetGRPtr (struct _Unwind_Context *context, int index)
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{
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index = DWARF_REG_TO_UNWIND_COLUMN (index);
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if (_Unwind_IsExtendedContext (context) && context->by_value[index])
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return &context->reg[index];
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return (void *) (_Unwind_Internal_Ptr) context->reg[index];
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}
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/* Set the pointer to a register INDEX as saved in CONTEXT. */
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static inline void
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_Unwind_SetGRPtr (struct _Unwind_Context *context, int index, void *p)
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{
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index = DWARF_REG_TO_UNWIND_COLUMN (index);
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if (_Unwind_IsExtendedContext (context))
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context->by_value[index] = 0;
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context->reg[index] = (_Unwind_Context_Reg_Val) (_Unwind_Internal_Ptr) p;
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}
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/* Overwrite the saved value for register INDEX in CONTEXT with VAL. */
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static inline void
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_Unwind_SetGRValue (struct _Unwind_Context *context, int index,
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_Unwind_Word val)
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{
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index = DWARF_REG_TO_UNWIND_COLUMN (index);
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gcc_assert (index < (int) sizeof(dwarf_reg_size_table));
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/* Return column size may be smaller than _Unwind_Context_Reg_Val. */
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gcc_assert (dwarf_reg_size_table[index] <= sizeof (_Unwind_Context_Reg_Val));
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context->by_value[index] = 1;
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context->reg[index] = _Unwind_Get_Unwind_Context_Reg_Val (val);
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}
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||
/* Return nonzero if register INDEX is stored by value rather than
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by reference. */
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static inline int
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_Unwind_GRByValue (struct _Unwind_Context *context, int index)
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{
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index = DWARF_REG_TO_UNWIND_COLUMN (index);
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return context->by_value[index];
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||
}
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||
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/* Retrieve the return address for CONTEXT. */
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||
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inline _Unwind_Ptr
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_Unwind_GetIP (struct _Unwind_Context *context)
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{
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||
return (_Unwind_Ptr) context->ra;
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}
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/* Retrieve the return address and flag whether that IP is before
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or after first not yet fully executed instruction. */
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||
inline _Unwind_Ptr
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_Unwind_GetIPInfo (struct _Unwind_Context *context, int *ip_before_insn)
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{
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*ip_before_insn = _Unwind_IsSignalFrame (context);
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||
return (_Unwind_Ptr) context->ra;
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||
}
|
||
|
||
/* Overwrite the return address for CONTEXT with VAL. */
|
||
|
||
inline void
|
||
_Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val)
|
||
{
|
||
context->ra = (void *) val;
|
||
}
|
||
|
||
void *
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_Unwind_GetLanguageSpecificData (struct _Unwind_Context *context)
|
||
{
|
||
return context->lsda;
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||
}
|
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|
||
_Unwind_Ptr
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||
_Unwind_GetRegionStart (struct _Unwind_Context *context)
|
||
{
|
||
return (_Unwind_Ptr) context->bases.func;
|
||
}
|
||
|
||
void *
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||
_Unwind_FindEnclosingFunction (void *pc)
|
||
{
|
||
struct dwarf_eh_bases bases;
|
||
const struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases);
|
||
if (fde)
|
||
return bases.func;
|
||
else
|
||
return NULL;
|
||
}
|
||
|
||
#ifndef __ia64__
|
||
_Unwind_Ptr
|
||
_Unwind_GetDataRelBase (struct _Unwind_Context *context)
|
||
{
|
||
return (_Unwind_Ptr) context->bases.dbase;
|
||
}
|
||
|
||
_Unwind_Ptr
|
||
_Unwind_GetTextRelBase (struct _Unwind_Context *context)
|
||
{
|
||
return (_Unwind_Ptr) context->bases.tbase;
|
||
}
|
||
#endif
|
||
|
||
#include "md-unwind-support.h"
|
||
|
||
/* Extract any interesting information from the CIE for the translation
|
||
unit F belongs to. Return a pointer to the byte after the augmentation,
|
||
or NULL if we encountered an undecipherable augmentation. */
|
||
|
||
static const unsigned char *
|
||
extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context,
|
||
_Unwind_FrameState *fs)
|
||
{
|
||
const unsigned char *aug = cie->augmentation;
|
||
const unsigned char *p = aug + strlen ((const char *)aug) + 1;
|
||
const unsigned char *ret = NULL;
|
||
_uleb128_t utmp;
|
||
_sleb128_t stmp;
|
||
|
||
/* g++ v2 "eh" has pointer immediately following augmentation string,
|
||
so it must be handled first. */
|
||
if (aug[0] == 'e' && aug[1] == 'h')
|
||
{
|
||
fs->eh_ptr = read_pointer (p);
|
||
p += sizeof (void *);
|
||
aug += 2;
|
||
}
|
||
|
||
/* After the augmentation resp. pointer for "eh" augmentation
|
||
follows for CIE version >= 4 address size byte and
|
||
segment size byte. */
|
||
if (__builtin_expect (cie->version >= 4, 0))
|
||
{
|
||
if (p[0] != sizeof (void *) || p[1] != 0)
|
||
return NULL;
|
||
p += 2;
|
||
}
|
||
/* Immediately following this are the code and
|
||
data alignment and return address column. */
|
||
p = read_uleb128 (p, &utmp);
|
||
fs->code_align = (_Unwind_Word)utmp;
|
||
p = read_sleb128 (p, &stmp);
|
||
fs->data_align = (_Unwind_Sword)stmp;
|
||
if (cie->version == 1)
|
||
fs->retaddr_column = *p++;
|
||
else
|
||
{
|
||
p = read_uleb128 (p, &utmp);
|
||
fs->retaddr_column = (_Unwind_Word)utmp;
|
||
}
|
||
fs->lsda_encoding = DW_EH_PE_omit;
|
||
|
||
/* If the augmentation starts with 'z', then a uleb128 immediately
|
||
follows containing the length of the augmentation field following
|
||
the size. */
|
||
if (*aug == 'z')
|
||
{
|
||
p = read_uleb128 (p, &utmp);
|
||
ret = p + utmp;
|
||
|
||
fs->saw_z = 1;
|
||
++aug;
|
||
}
|
||
|
||
/* Iterate over recognized augmentation subsequences. */
|
||
while (*aug != '\0')
|
||
{
|
||
/* "L" indicates a byte showing how the LSDA pointer is encoded. */
|
||
if (aug[0] == 'L')
|
||
{
|
||
fs->lsda_encoding = *p++;
|
||
aug += 1;
|
||
}
|
||
|
||
/* "R" indicates a byte indicating how FDE addresses are encoded. */
|
||
else if (aug[0] == 'R')
|
||
{
|
||
fs->fde_encoding = *p++;
|
||
aug += 1;
|
||
}
|
||
|
||
/* "P" indicates a personality routine in the CIE augmentation. */
|
||
else if (aug[0] == 'P')
|
||
{
|
||
_Unwind_Ptr personality;
|
||
|
||
p = read_encoded_value (context, *p, p + 1, &personality);
|
||
fs->personality = (_Unwind_Personality_Fn) personality;
|
||
aug += 1;
|
||
}
|
||
|
||
/* "S" indicates a signal frame. */
|
||
else if (aug[0] == 'S')
|
||
{
|
||
fs->signal_frame = 1;
|
||
aug += 1;
|
||
}
|
||
|
||
/* Otherwise we have an unknown augmentation string.
|
||
Bail unless we saw a 'z' prefix. */
|
||
else
|
||
return ret;
|
||
}
|
||
|
||
return ret ? ret : p;
|
||
}
|
||
|
||
|
||
/* Decode a DW_OP stack program. Return the top of stack. Push INITIAL
|
||
onto the stack to start. */
|
||
|
||
static _Unwind_Word
|
||
execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end,
|
||
struct _Unwind_Context *context, _Unwind_Word initial)
|
||
{
|
||
_Unwind_Word stack[64]; /* ??? Assume this is enough. */
|
||
int stack_elt;
|
||
|
||
stack[0] = initial;
|
||
stack_elt = 1;
|
||
|
||
while (op_ptr < op_end)
|
||
{
|
||
enum dwarf_location_atom op = *op_ptr++;
|
||
_Unwind_Word result;
|
||
_uleb128_t reg, utmp;
|
||
_sleb128_t offset, stmp;
|
||
|
||
switch (op)
|
||
{
|
||
case DW_OP_lit0:
|
||
case DW_OP_lit1:
|
||
case DW_OP_lit2:
|
||
case DW_OP_lit3:
|
||
case DW_OP_lit4:
|
||
case DW_OP_lit5:
|
||
case DW_OP_lit6:
|
||
case DW_OP_lit7:
|
||
case DW_OP_lit8:
|
||
case DW_OP_lit9:
|
||
case DW_OP_lit10:
|
||
case DW_OP_lit11:
|
||
case DW_OP_lit12:
|
||
case DW_OP_lit13:
|
||
case DW_OP_lit14:
|
||
case DW_OP_lit15:
|
||
case DW_OP_lit16:
|
||
case DW_OP_lit17:
|
||
case DW_OP_lit18:
|
||
case DW_OP_lit19:
|
||
case DW_OP_lit20:
|
||
case DW_OP_lit21:
|
||
case DW_OP_lit22:
|
||
case DW_OP_lit23:
|
||
case DW_OP_lit24:
|
||
case DW_OP_lit25:
|
||
case DW_OP_lit26:
|
||
case DW_OP_lit27:
|
||
case DW_OP_lit28:
|
||
case DW_OP_lit29:
|
||
case DW_OP_lit30:
|
||
case DW_OP_lit31:
|
||
result = op - DW_OP_lit0;
|
||
break;
|
||
|
||
case DW_OP_addr:
|
||
result = (_Unwind_Word) (_Unwind_Ptr) read_pointer (op_ptr);
|
||
op_ptr += sizeof (void *);
|
||
break;
|
||
|
||
case DW_OP_GNU_encoded_addr:
|
||
{
|
||
_Unwind_Ptr presult;
|
||
op_ptr = read_encoded_value (context, *op_ptr, op_ptr+1, &presult);
|
||
result = presult;
|
||
}
|
||
break;
|
||
|
||
case DW_OP_const1u:
|
||
result = read_1u (op_ptr);
|
||
op_ptr += 1;
|
||
break;
|
||
case DW_OP_const1s:
|
||
result = read_1s (op_ptr);
|
||
op_ptr += 1;
|
||
break;
|
||
case DW_OP_const2u:
|
||
result = read_2u (op_ptr);
|
||
op_ptr += 2;
|
||
break;
|
||
case DW_OP_const2s:
|
||
result = read_2s (op_ptr);
|
||
op_ptr += 2;
|
||
break;
|
||
case DW_OP_const4u:
|
||
result = read_4u (op_ptr);
|
||
op_ptr += 4;
|
||
break;
|
||
case DW_OP_const4s:
|
||
result = read_4s (op_ptr);
|
||
op_ptr += 4;
|
||
break;
|
||
case DW_OP_const8u:
|
||
result = read_8u (op_ptr);
|
||
op_ptr += 8;
|
||
break;
|
||
case DW_OP_const8s:
|
||
result = read_8s (op_ptr);
|
||
op_ptr += 8;
|
||
break;
|
||
case DW_OP_constu:
|
||
op_ptr = read_uleb128 (op_ptr, &utmp);
|
||
result = (_Unwind_Word)utmp;
|
||
break;
|
||
case DW_OP_consts:
|
||
op_ptr = read_sleb128 (op_ptr, &stmp);
|
||
result = (_Unwind_Sword)stmp;
|
||
break;
|
||
|
||
case DW_OP_reg0:
|
||
case DW_OP_reg1:
|
||
case DW_OP_reg2:
|
||
case DW_OP_reg3:
|
||
case DW_OP_reg4:
|
||
case DW_OP_reg5:
|
||
case DW_OP_reg6:
|
||
case DW_OP_reg7:
|
||
case DW_OP_reg8:
|
||
case DW_OP_reg9:
|
||
case DW_OP_reg10:
|
||
case DW_OP_reg11:
|
||
case DW_OP_reg12:
|
||
case DW_OP_reg13:
|
||
case DW_OP_reg14:
|
||
case DW_OP_reg15:
|
||
case DW_OP_reg16:
|
||
case DW_OP_reg17:
|
||
case DW_OP_reg18:
|
||
case DW_OP_reg19:
|
||
case DW_OP_reg20:
|
||
case DW_OP_reg21:
|
||
case DW_OP_reg22:
|
||
case DW_OP_reg23:
|
||
case DW_OP_reg24:
|
||
case DW_OP_reg25:
|
||
case DW_OP_reg26:
|
||
case DW_OP_reg27:
|
||
case DW_OP_reg28:
|
||
case DW_OP_reg29:
|
||
case DW_OP_reg30:
|
||
case DW_OP_reg31:
|
||
result = _Unwind_GetGR (context, op - DW_OP_reg0);
|
||
break;
|
||
case DW_OP_regx:
|
||
op_ptr = read_uleb128 (op_ptr, ®);
|
||
result = _Unwind_GetGR (context, reg);
|
||
break;
|
||
|
||
case DW_OP_breg0:
|
||
case DW_OP_breg1:
|
||
case DW_OP_breg2:
|
||
case DW_OP_breg3:
|
||
case DW_OP_breg4:
|
||
case DW_OP_breg5:
|
||
case DW_OP_breg6:
|
||
case DW_OP_breg7:
|
||
case DW_OP_breg8:
|
||
case DW_OP_breg9:
|
||
case DW_OP_breg10:
|
||
case DW_OP_breg11:
|
||
case DW_OP_breg12:
|
||
case DW_OP_breg13:
|
||
case DW_OP_breg14:
|
||
case DW_OP_breg15:
|
||
case DW_OP_breg16:
|
||
case DW_OP_breg17:
|
||
case DW_OP_breg18:
|
||
case DW_OP_breg19:
|
||
case DW_OP_breg20:
|
||
case DW_OP_breg21:
|
||
case DW_OP_breg22:
|
||
case DW_OP_breg23:
|
||
case DW_OP_breg24:
|
||
case DW_OP_breg25:
|
||
case DW_OP_breg26:
|
||
case DW_OP_breg27:
|
||
case DW_OP_breg28:
|
||
case DW_OP_breg29:
|
||
case DW_OP_breg30:
|
||
case DW_OP_breg31:
|
||
op_ptr = read_sleb128 (op_ptr, &offset);
|
||
result = _Unwind_GetGR (context, op - DW_OP_breg0) + offset;
|
||
break;
|
||
case DW_OP_bregx:
|
||
op_ptr = read_uleb128 (op_ptr, ®);
|
||
op_ptr = read_sleb128 (op_ptr, &offset);
|
||
result = _Unwind_GetGR (context, reg) + (_Unwind_Word)offset;
|
||
break;
|
||
|
||
case DW_OP_dup:
|
||
gcc_assert (stack_elt);
|
||
result = stack[stack_elt - 1];
|
||
break;
|
||
|
||
case DW_OP_drop:
|
||
gcc_assert (stack_elt);
|
||
stack_elt -= 1;
|
||
goto no_push;
|
||
|
||
case DW_OP_pick:
|
||
offset = *op_ptr++;
|
||
gcc_assert (offset < stack_elt - 1);
|
||
result = stack[stack_elt - 1 - offset];
|
||
break;
|
||
|
||
case DW_OP_over:
|
||
gcc_assert (stack_elt >= 2);
|
||
result = stack[stack_elt - 2];
|
||
break;
|
||
|
||
case DW_OP_swap:
|
||
{
|
||
_Unwind_Word t;
|
||
gcc_assert (stack_elt >= 2);
|
||
t = stack[stack_elt - 1];
|
||
stack[stack_elt - 1] = stack[stack_elt - 2];
|
||
stack[stack_elt - 2] = t;
|
||
goto no_push;
|
||
}
|
||
|
||
case DW_OP_rot:
|
||
{
|
||
_Unwind_Word t1, t2, t3;
|
||
|
||
gcc_assert (stack_elt >= 3);
|
||
t1 = stack[stack_elt - 1];
|
||
t2 = stack[stack_elt - 2];
|
||
t3 = stack[stack_elt - 3];
|
||
stack[stack_elt - 1] = t2;
|
||
stack[stack_elt - 2] = t3;
|
||
stack[stack_elt - 3] = t1;
|
||
goto no_push;
|
||
}
|
||
|
||
case DW_OP_deref:
|
||
case DW_OP_deref_size:
|
||
case DW_OP_abs:
|
||
case DW_OP_neg:
|
||
case DW_OP_not:
|
||
case DW_OP_plus_uconst:
|
||
/* Unary operations. */
|
||
gcc_assert (stack_elt);
|
||
stack_elt -= 1;
|
||
|
||
result = stack[stack_elt];
|
||
|
||
switch (op)
|
||
{
|
||
case DW_OP_deref:
|
||
{
|
||
void *ptr = (void *) (_Unwind_Ptr) result;
|
||
result = (_Unwind_Ptr) read_pointer (ptr);
|
||
}
|
||
break;
|
||
|
||
case DW_OP_deref_size:
|
||
{
|
||
void *ptr = (void *) (_Unwind_Ptr) result;
|
||
switch (*op_ptr++)
|
||
{
|
||
case 1:
|
||
result = read_1u (ptr);
|
||
break;
|
||
case 2:
|
||
result = read_2u (ptr);
|
||
break;
|
||
case 4:
|
||
result = read_4u (ptr);
|
||
break;
|
||
case 8:
|
||
result = read_8u (ptr);
|
||
break;
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DW_OP_abs:
|
||
if ((_Unwind_Sword) result < 0)
|
||
result = -result;
|
||
break;
|
||
case DW_OP_neg:
|
||
result = -result;
|
||
break;
|
||
case DW_OP_not:
|
||
result = ~result;
|
||
break;
|
||
case DW_OP_plus_uconst:
|
||
op_ptr = read_uleb128 (op_ptr, &utmp);
|
||
result += (_Unwind_Word)utmp;
|
||
break;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
break;
|
||
|
||
case DW_OP_and:
|
||
case DW_OP_div:
|
||
case DW_OP_minus:
|
||
case DW_OP_mod:
|
||
case DW_OP_mul:
|
||
case DW_OP_or:
|
||
case DW_OP_plus:
|
||
case DW_OP_shl:
|
||
case DW_OP_shr:
|
||
case DW_OP_shra:
|
||
case DW_OP_xor:
|
||
case DW_OP_le:
|
||
case DW_OP_ge:
|
||
case DW_OP_eq:
|
||
case DW_OP_lt:
|
||
case DW_OP_gt:
|
||
case DW_OP_ne:
|
||
{
|
||
/* Binary operations. */
|
||
_Unwind_Word first, second;
|
||
gcc_assert (stack_elt >= 2);
|
||
stack_elt -= 2;
|
||
|
||
second = stack[stack_elt];
|
||
first = stack[stack_elt + 1];
|
||
|
||
switch (op)
|
||
{
|
||
case DW_OP_and:
|
||
result = second & first;
|
||
break;
|
||
case DW_OP_div:
|
||
result = (_Unwind_Sword) second / (_Unwind_Sword) first;
|
||
break;
|
||
case DW_OP_minus:
|
||
result = second - first;
|
||
break;
|
||
case DW_OP_mod:
|
||
result = second % first;
|
||
break;
|
||
case DW_OP_mul:
|
||
result = second * first;
|
||
break;
|
||
case DW_OP_or:
|
||
result = second | first;
|
||
break;
|
||
case DW_OP_plus:
|
||
result = second + first;
|
||
break;
|
||
case DW_OP_shl:
|
||
result = second << first;
|
||
break;
|
||
case DW_OP_shr:
|
||
result = second >> first;
|
||
break;
|
||
case DW_OP_shra:
|
||
result = (_Unwind_Sword) second >> first;
|
||
break;
|
||
case DW_OP_xor:
|
||
result = second ^ first;
|
||
break;
|
||
case DW_OP_le:
|
||
result = (_Unwind_Sword) second <= (_Unwind_Sword) first;
|
||
break;
|
||
case DW_OP_ge:
|
||
result = (_Unwind_Sword) second >= (_Unwind_Sword) first;
|
||
break;
|
||
case DW_OP_eq:
|
||
result = (_Unwind_Sword) second == (_Unwind_Sword) first;
|
||
break;
|
||
case DW_OP_lt:
|
||
result = (_Unwind_Sword) second < (_Unwind_Sword) first;
|
||
break;
|
||
case DW_OP_gt:
|
||
result = (_Unwind_Sword) second > (_Unwind_Sword) first;
|
||
break;
|
||
case DW_OP_ne:
|
||
result = (_Unwind_Sword) second != (_Unwind_Sword) first;
|
||
break;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DW_OP_skip:
|
||
offset = read_2s (op_ptr);
|
||
op_ptr += 2;
|
||
op_ptr += offset;
|
||
goto no_push;
|
||
|
||
case DW_OP_bra:
|
||
gcc_assert (stack_elt);
|
||
stack_elt -= 1;
|
||
|
||
offset = read_2s (op_ptr);
|
||
op_ptr += 2;
|
||
if (stack[stack_elt] != 0)
|
||
op_ptr += offset;
|
||
goto no_push;
|
||
|
||
case DW_OP_nop:
|
||
goto no_push;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
|
||
/* Most things push a result value. */
|
||
gcc_assert ((size_t) stack_elt < sizeof(stack)/sizeof(*stack));
|
||
stack[stack_elt++] = result;
|
||
no_push:;
|
||
}
|
||
|
||
/* We were executing this program to get a value. It should be
|
||
at top of stack. */
|
||
gcc_assert (stack_elt);
|
||
stack_elt -= 1;
|
||
return stack[stack_elt];
|
||
}
|
||
|
||
|
||
/* Decode DWARF 2 call frame information. Takes pointers the
|
||
instruction sequence to decode, current register information and
|
||
CIE info, and the PC range to evaluate. */
|
||
|
||
static void
|
||
execute_cfa_program (const unsigned char *insn_ptr,
|
||
const unsigned char *insn_end,
|
||
struct _Unwind_Context *context,
|
||
_Unwind_FrameState *fs)
|
||
{
|
||
struct frame_state_reg_info *unused_rs = NULL;
|
||
|
||
/* Don't allow remember/restore between CIE and FDE programs. */
|
||
fs->regs.prev = NULL;
|
||
|
||
/* The comparison with the return address uses < rather than <= because
|
||
we are only interested in the effects of code before the call; for a
|
||
noreturn function, the return address may point to unrelated code with
|
||
a different stack configuration that we are not interested in. We
|
||
assume that the call itself is unwind info-neutral; if not, or if
|
||
there are delay instructions that adjust the stack, these must be
|
||
reflected at the point immediately before the call insn.
|
||
In signal frames, return address is after last completed instruction,
|
||
so we add 1 to return address to make the comparison <=. */
|
||
while (insn_ptr < insn_end
|
||
&& fs->pc < context->ra + _Unwind_IsSignalFrame (context))
|
||
{
|
||
unsigned char insn = *insn_ptr++;
|
||
_uleb128_t reg, utmp;
|
||
_sleb128_t offset, stmp;
|
||
|
||
if ((insn & 0xc0) == DW_CFA_advance_loc)
|
||
fs->pc += (insn & 0x3f) * fs->code_align;
|
||
else if ((insn & 0xc0) == DW_CFA_offset)
|
||
{
|
||
reg = insn & 0x3f;
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
offset = (_Unwind_Sword) utmp * fs->data_align;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = offset;
|
||
}
|
||
}
|
||
else if ((insn & 0xc0) == DW_CFA_restore)
|
||
{
|
||
reg = insn & 0x3f;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
fs->regs.reg[reg].how = REG_UNSAVED;
|
||
}
|
||
else switch (insn)
|
||
{
|
||
case DW_CFA_set_loc:
|
||
{
|
||
_Unwind_Ptr pc;
|
||
|
||
insn_ptr = read_encoded_value (context, fs->fde_encoding,
|
||
insn_ptr, &pc);
|
||
fs->pc = (void *) pc;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_advance_loc1:
|
||
fs->pc += read_1u (insn_ptr) * fs->code_align;
|
||
insn_ptr += 1;
|
||
break;
|
||
case DW_CFA_advance_loc2:
|
||
fs->pc += read_2u (insn_ptr) * fs->code_align;
|
||
insn_ptr += 2;
|
||
break;
|
||
case DW_CFA_advance_loc4:
|
||
fs->pc += read_4u (insn_ptr) * fs->code_align;
|
||
insn_ptr += 4;
|
||
break;
|
||
|
||
case DW_CFA_offset_extended:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
offset = (_Unwind_Sword) utmp * fs->data_align;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = offset;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_restore_extended:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
/* FIXME, this is wrong; the CIE might have said that the
|
||
register was saved somewhere. */
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
fs->regs.reg[reg].how = REG_UNSAVED;
|
||
break;
|
||
|
||
case DW_CFA_same_value:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
fs->regs.reg[reg].how = REG_UNSAVED;
|
||
break;
|
||
|
||
case DW_CFA_undefined:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
fs->regs.reg[reg].how = REG_UNDEFINED;
|
||
break;
|
||
|
||
case DW_CFA_nop:
|
||
break;
|
||
|
||
case DW_CFA_register:
|
||
{
|
||
_uleb128_t reg2;
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
insn_ptr = read_uleb128 (insn_ptr, ®2);
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_REG;
|
||
fs->regs.reg[reg].loc.reg = (_Unwind_Word)reg2;
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_remember_state:
|
||
{
|
||
struct frame_state_reg_info *new_rs;
|
||
if (unused_rs)
|
||
{
|
||
new_rs = unused_rs;
|
||
unused_rs = unused_rs->prev;
|
||
}
|
||
else
|
||
new_rs = alloca (sizeof (struct frame_state_reg_info));
|
||
|
||
*new_rs = fs->regs;
|
||
fs->regs.prev = new_rs;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_restore_state:
|
||
{
|
||
struct frame_state_reg_info *old_rs = fs->regs.prev;
|
||
fs->regs = *old_rs;
|
||
old_rs->prev = unused_rs;
|
||
unused_rs = old_rs;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_def_cfa:
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
fs->regs.cfa_reg = (_Unwind_Word)utmp;
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
fs->regs.cfa_offset = (_Unwind_Word)utmp;
|
||
fs->regs.cfa_how = CFA_REG_OFFSET;
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_register:
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
fs->regs.cfa_reg = (_Unwind_Word)utmp;
|
||
fs->regs.cfa_how = CFA_REG_OFFSET;
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_offset:
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
fs->regs.cfa_offset = utmp;
|
||
/* cfa_how deliberately not set. */
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_expression:
|
||
fs->regs.cfa_exp = insn_ptr;
|
||
fs->regs.cfa_how = CFA_EXP;
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
insn_ptr += utmp;
|
||
break;
|
||
|
||
case DW_CFA_expression:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_EXP;
|
||
fs->regs.reg[reg].loc.exp = insn_ptr;
|
||
}
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
insn_ptr += utmp;
|
||
break;
|
||
|
||
/* Dwarf3. */
|
||
case DW_CFA_offset_extended_sf:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
insn_ptr = read_sleb128 (insn_ptr, &stmp);
|
||
offset = stmp * fs->data_align;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = offset;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_sf:
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
fs->regs.cfa_reg = (_Unwind_Word)utmp;
|
||
insn_ptr = read_sleb128 (insn_ptr, &stmp);
|
||
fs->regs.cfa_offset = (_Unwind_Sword)stmp;
|
||
fs->regs.cfa_how = CFA_REG_OFFSET;
|
||
fs->regs.cfa_offset *= fs->data_align;
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_offset_sf:
|
||
insn_ptr = read_sleb128 (insn_ptr, &stmp);
|
||
fs->regs.cfa_offset = (_Unwind_Sword)stmp;
|
||
fs->regs.cfa_offset *= fs->data_align;
|
||
/* cfa_how deliberately not set. */
|
||
break;
|
||
|
||
case DW_CFA_val_offset:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
offset = (_Unwind_Sword) utmp * fs->data_align;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_VAL_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = offset;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_val_offset_sf:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
insn_ptr = read_sleb128 (insn_ptr, &stmp);
|
||
offset = stmp * fs->data_align;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_VAL_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = offset;
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_val_expression:
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_VAL_EXP;
|
||
fs->regs.reg[reg].loc.exp = insn_ptr;
|
||
}
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
insn_ptr += utmp;
|
||
break;
|
||
|
||
case DW_CFA_GNU_window_save:
|
||
/* ??? Hardcoded for SPARC register window configuration. */
|
||
if (DWARF_FRAME_REGISTERS >= 32)
|
||
for (reg = 16; reg < 32; ++reg)
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = (reg - 16) * sizeof (void *);
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_GNU_args_size:
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
context->args_size = (_Unwind_Word)utmp;
|
||
break;
|
||
|
||
case DW_CFA_GNU_negative_offset_extended:
|
||
/* Obsoleted by DW_CFA_offset_extended_sf, but used by
|
||
older PowerPC code. */
|
||
insn_ptr = read_uleb128 (insn_ptr, ®);
|
||
insn_ptr = read_uleb128 (insn_ptr, &utmp);
|
||
offset = (_Unwind_Word) utmp * fs->data_align;
|
||
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
|
||
if (UNWIND_COLUMN_IN_RANGE (reg))
|
||
{
|
||
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
|
||
fs->regs.reg[reg].loc.offset = -offset;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for
|
||
its caller and decode it into FS. This function also sets the
|
||
args_size and lsda members of CONTEXT, as they are really information
|
||
about the caller's frame. */
|
||
|
||
static _Unwind_Reason_Code
|
||
uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs)
|
||
{
|
||
const struct dwarf_fde *fde;
|
||
const struct dwarf_cie *cie;
|
||
const unsigned char *aug, *insn, *end;
|
||
|
||
memset (fs, 0, sizeof (*fs));
|
||
context->args_size = 0;
|
||
context->lsda = 0;
|
||
|
||
if (context->ra == 0)
|
||
return _URC_END_OF_STACK;
|
||
|
||
fde = _Unwind_Find_FDE (context->ra + _Unwind_IsSignalFrame (context) - 1,
|
||
&context->bases);
|
||
if (fde == NULL)
|
||
{
|
||
#ifdef MD_FALLBACK_FRAME_STATE_FOR
|
||
/* Couldn't find frame unwind info for this function. Try a
|
||
target-specific fallback mechanism. This will necessarily
|
||
not provide a personality routine or LSDA. */
|
||
return MD_FALLBACK_FRAME_STATE_FOR (context, fs);
|
||
#else
|
||
return _URC_END_OF_STACK;
|
||
#endif
|
||
}
|
||
|
||
fs->pc = context->bases.func;
|
||
|
||
cie = get_cie (fde);
|
||
insn = extract_cie_info (cie, context, fs);
|
||
if (insn == NULL)
|
||
/* CIE contained unknown augmentation. */
|
||
return _URC_FATAL_PHASE1_ERROR;
|
||
|
||
/* First decode all the insns in the CIE. */
|
||
end = (const unsigned char *) next_fde ((const struct dwarf_fde *) cie);
|
||
execute_cfa_program (insn, end, context, fs);
|
||
|
||
/* Locate augmentation for the fde. */
|
||
aug = (const unsigned char *) fde + sizeof (*fde);
|
||
aug += 2 * size_of_encoded_value (fs->fde_encoding);
|
||
insn = NULL;
|
||
if (fs->saw_z)
|
||
{
|
||
_uleb128_t i;
|
||
aug = read_uleb128 (aug, &i);
|
||
insn = aug + i;
|
||
}
|
||
if (fs->lsda_encoding != DW_EH_PE_omit)
|
||
{
|
||
_Unwind_Ptr lsda;
|
||
|
||
aug = read_encoded_value (context, fs->lsda_encoding, aug, &lsda);
|
||
context->lsda = (void *) lsda;
|
||
}
|
||
|
||
/* Then the insns in the FDE up to our target PC. */
|
||
if (insn == NULL)
|
||
insn = aug;
|
||
end = (const unsigned char *) next_fde (fde);
|
||
execute_cfa_program (insn, end, context, fs);
|
||
|
||
return _URC_NO_REASON;
|
||
}
|
||
|
||
typedef struct frame_state
|
||
{
|
||
void *cfa;
|
||
void *eh_ptr;
|
||
long cfa_offset;
|
||
long args_size;
|
||
long reg_or_offset[PRE_GCC3_DWARF_FRAME_REGISTERS+1];
|
||
unsigned short cfa_reg;
|
||
unsigned short retaddr_column;
|
||
char saved[PRE_GCC3_DWARF_FRAME_REGISTERS+1];
|
||
} frame_state;
|
||
|
||
struct frame_state * __frame_state_for (void *, struct frame_state *);
|
||
|
||
/* Called from pre-G++ 3.0 __throw to find the registers to restore for
|
||
a given PC_TARGET. The caller should allocate a local variable of
|
||
`struct frame_state' and pass its address to STATE_IN. */
|
||
|
||
struct frame_state *
|
||
__frame_state_for (void *pc_target, struct frame_state *state_in)
|
||
{
|
||
struct _Unwind_Context context;
|
||
_Unwind_FrameState fs;
|
||
int reg;
|
||
|
||
memset (&context, 0, sizeof (struct _Unwind_Context));
|
||
if (!ASSUME_EXTENDED_UNWIND_CONTEXT)
|
||
context.flags = EXTENDED_CONTEXT_BIT;
|
||
context.ra = pc_target + 1;
|
||
|
||
if (uw_frame_state_for (&context, &fs) != _URC_NO_REASON)
|
||
return 0;
|
||
|
||
/* We have no way to pass a location expression for the CFA to our
|
||
caller. It wouldn't understand it anyway. */
|
||
if (fs.regs.cfa_how == CFA_EXP)
|
||
return 0;
|
||
|
||
for (reg = 0; reg < PRE_GCC3_DWARF_FRAME_REGISTERS + 1; reg++)
|
||
{
|
||
state_in->saved[reg] = fs.regs.reg[reg].how;
|
||
switch (state_in->saved[reg])
|
||
{
|
||
case REG_SAVED_REG:
|
||
state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.reg;
|
||
break;
|
||
case REG_SAVED_OFFSET:
|
||
state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.offset;
|
||
break;
|
||
default:
|
||
state_in->reg_or_offset[reg] = 0;
|
||
break;
|
||
}
|
||
}
|
||
|
||
state_in->cfa_offset = fs.regs.cfa_offset;
|
||
state_in->cfa_reg = fs.regs.cfa_reg;
|
||
state_in->retaddr_column = fs.retaddr_column;
|
||
state_in->args_size = context.args_size;
|
||
state_in->eh_ptr = fs.eh_ptr;
|
||
|
||
return state_in;
|
||
}
|
||
|
||
typedef union { _Unwind_Ptr ptr; _Unwind_Word word; } _Unwind_SpTmp;
|
||
|
||
static inline void
|
||
_Unwind_SetSpColumn (struct _Unwind_Context *context, void *cfa,
|
||
_Unwind_SpTmp *tmp_sp)
|
||
{
|
||
int size = dwarf_reg_size_table[__builtin_dwarf_sp_column ()];
|
||
|
||
if (size == sizeof(_Unwind_Ptr))
|
||
tmp_sp->ptr = (_Unwind_Ptr) cfa;
|
||
else
|
||
{
|
||
gcc_assert (size == sizeof(_Unwind_Word));
|
||
tmp_sp->word = (_Unwind_Ptr) cfa;
|
||
}
|
||
_Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), tmp_sp);
|
||
}
|
||
|
||
static void
|
||
uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs)
|
||
{
|
||
struct _Unwind_Context orig_context = *context;
|
||
void *cfa;
|
||
long i;
|
||
|
||
#ifdef EH_RETURN_STACKADJ_RTX
|
||
/* Special handling here: Many machines do not use a frame pointer,
|
||
and track the CFA only through offsets from the stack pointer from
|
||
one frame to the next. In this case, the stack pointer is never
|
||
stored, so it has no saved address in the context. What we do
|
||
have is the CFA from the previous stack frame.
|
||
|
||
In very special situations (such as unwind info for signal return),
|
||
there may be location expressions that use the stack pointer as well.
|
||
|
||
Do this conditionally for one frame. This allows the unwind info
|
||
for one frame to save a copy of the stack pointer from the previous
|
||
frame, and be able to use much easier CFA mechanisms to do it.
|
||
Always zap the saved stack pointer value for the next frame; carrying
|
||
the value over from one frame to another doesn't make sense. */
|
||
|
||
_Unwind_SpTmp tmp_sp;
|
||
|
||
if (!_Unwind_GetGRPtr (&orig_context, __builtin_dwarf_sp_column ()))
|
||
_Unwind_SetSpColumn (&orig_context, context->cfa, &tmp_sp);
|
||
_Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), NULL);
|
||
#endif
|
||
|
||
/* Compute this frame's CFA. */
|
||
switch (fs->regs.cfa_how)
|
||
{
|
||
case CFA_REG_OFFSET:
|
||
cfa = _Unwind_GetPtr (&orig_context, fs->regs.cfa_reg);
|
||
cfa += fs->regs.cfa_offset;
|
||
break;
|
||
|
||
case CFA_EXP:
|
||
{
|
||
const unsigned char *exp = fs->regs.cfa_exp;
|
||
_uleb128_t len;
|
||
|
||
exp = read_uleb128 (exp, &len);
|
||
cfa = (void *) (_Unwind_Ptr)
|
||
execute_stack_op (exp, exp + len, &orig_context, 0);
|
||
break;
|
||
}
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
context->cfa = cfa;
|
||
|
||
/* Compute the addresses of all registers saved in this frame. */
|
||
for (i = 0; i < DWARF_FRAME_REGISTERS + 1; ++i)
|
||
switch (fs->regs.reg[i].how)
|
||
{
|
||
case REG_UNSAVED:
|
||
case REG_UNDEFINED:
|
||
break;
|
||
|
||
case REG_SAVED_OFFSET:
|
||
_Unwind_SetGRPtr (context, i,
|
||
(void *) (cfa + fs->regs.reg[i].loc.offset));
|
||
break;
|
||
|
||
case REG_SAVED_REG:
|
||
if (_Unwind_GRByValue (&orig_context, fs->regs.reg[i].loc.reg))
|
||
_Unwind_SetGRValue (context, i,
|
||
_Unwind_GetGR (&orig_context,
|
||
fs->regs.reg[i].loc.reg));
|
||
else
|
||
_Unwind_SetGRPtr (context, i,
|
||
_Unwind_GetGRPtr (&orig_context,
|
||
fs->regs.reg[i].loc.reg));
|
||
break;
|
||
|
||
case REG_SAVED_EXP:
|
||
{
|
||
const unsigned char *exp = fs->regs.reg[i].loc.exp;
|
||
_uleb128_t len;
|
||
_Unwind_Ptr val;
|
||
|
||
exp = read_uleb128 (exp, &len);
|
||
val = execute_stack_op (exp, exp + len, &orig_context,
|
||
(_Unwind_Ptr) cfa);
|
||
_Unwind_SetGRPtr (context, i, (void *) val);
|
||
}
|
||
break;
|
||
|
||
case REG_SAVED_VAL_OFFSET:
|
||
_Unwind_SetGRValue (context, i,
|
||
(_Unwind_Internal_Ptr)
|
||
(cfa + fs->regs.reg[i].loc.offset));
|
||
break;
|
||
|
||
case REG_SAVED_VAL_EXP:
|
||
{
|
||
const unsigned char *exp = fs->regs.reg[i].loc.exp;
|
||
_uleb128_t len;
|
||
_Unwind_Ptr val;
|
||
|
||
exp = read_uleb128 (exp, &len);
|
||
val = execute_stack_op (exp, exp + len, &orig_context,
|
||
(_Unwind_Ptr) cfa);
|
||
_Unwind_SetGRValue (context, i, val);
|
||
}
|
||
break;
|
||
}
|
||
|
||
_Unwind_SetSignalFrame (context, fs->signal_frame);
|
||
|
||
#ifdef MD_FROB_UPDATE_CONTEXT
|
||
MD_FROB_UPDATE_CONTEXT (context, fs);
|
||
#endif
|
||
}
|
||
|
||
/* CONTEXT describes the unwind state for a frame, and FS describes the FDE
|
||
of its caller. Update CONTEXT to refer to the caller as well. Note
|
||
that the args_size and lsda members are not updated here, but later in
|
||
uw_frame_state_for. */
|
||
|
||
static void
|
||
uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs)
|
||
{
|
||
uw_update_context_1 (context, fs);
|
||
|
||
/* In general this unwinder doesn't make any distinction between
|
||
undefined and same_value rule. Call-saved registers are assumed
|
||
to have same_value rule by default and explicit undefined
|
||
rule is handled like same_value. The only exception is
|
||
DW_CFA_undefined on retaddr_column which is supposed to
|
||
mark outermost frame in DWARF 3. */
|
||
if (fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (fs->retaddr_column)].how
|
||
== REG_UNDEFINED)
|
||
/* uw_frame_state_for uses context->ra == 0 check to find outermost
|
||
stack frame. */
|
||
context->ra = 0;
|
||
else
|
||
/* Compute the return address now, since the return address column
|
||
can change from frame to frame. */
|
||
context->ra = __builtin_extract_return_addr
|
||
(_Unwind_GetPtr (context, fs->retaddr_column));
|
||
}
|
||
|
||
static void
|
||
uw_advance_context (struct _Unwind_Context *context, _Unwind_FrameState *fs)
|
||
{
|
||
uw_update_context (context, fs);
|
||
}
|
||
|
||
/* Fill in CONTEXT for top-of-stack. The only valid registers at this
|
||
level will be the return address and the CFA. */
|
||
|
||
#define uw_init_context(CONTEXT) \
|
||
do \
|
||
{ \
|
||
/* Do any necessary initialization to access arbitrary stack frames. \
|
||
On the SPARC, this means flushing the register windows. */ \
|
||
__builtin_unwind_init (); \
|
||
uw_init_context_1 (CONTEXT, __builtin_dwarf_cfa (), \
|
||
__builtin_return_address (0)); \
|
||
} \
|
||
while (0)
|
||
|
||
static inline void
|
||
init_dwarf_reg_size_table (void)
|
||
{
|
||
__builtin_init_dwarf_reg_size_table (dwarf_reg_size_table);
|
||
}
|
||
|
||
static void __attribute__((noinline))
|
||
uw_init_context_1 (struct _Unwind_Context *context,
|
||
void *outer_cfa, void *outer_ra)
|
||
{
|
||
void *ra = __builtin_extract_return_addr (__builtin_return_address (0));
|
||
_Unwind_FrameState fs;
|
||
_Unwind_SpTmp sp_slot;
|
||
_Unwind_Reason_Code code;
|
||
|
||
memset (context, 0, sizeof (struct _Unwind_Context));
|
||
context->ra = ra;
|
||
if (!ASSUME_EXTENDED_UNWIND_CONTEXT)
|
||
context->flags = EXTENDED_CONTEXT_BIT;
|
||
|
||
code = uw_frame_state_for (context, &fs);
|
||
gcc_assert (code == _URC_NO_REASON);
|
||
|
||
#if __GTHREADS
|
||
{
|
||
static __gthread_once_t once_regsizes = __GTHREAD_ONCE_INIT;
|
||
if (__gthread_once (&once_regsizes, init_dwarf_reg_size_table) != 0
|
||
&& dwarf_reg_size_table[0] == 0)
|
||
init_dwarf_reg_size_table ();
|
||
}
|
||
#else
|
||
if (dwarf_reg_size_table[0] == 0)
|
||
init_dwarf_reg_size_table ();
|
||
#endif
|
||
|
||
/* Force the frame state to use the known cfa value. */
|
||
_Unwind_SetSpColumn (context, outer_cfa, &sp_slot);
|
||
fs.regs.cfa_how = CFA_REG_OFFSET;
|
||
fs.regs.cfa_reg = __builtin_dwarf_sp_column ();
|
||
fs.regs.cfa_offset = 0;
|
||
|
||
uw_update_context_1 (context, &fs);
|
||
|
||
/* If the return address column was saved in a register in the
|
||
initialization context, then we can't see it in the given
|
||
call frame data. So have the initialization context tell us. */
|
||
context->ra = __builtin_extract_return_addr (outer_ra);
|
||
}
|
||
|
||
static void _Unwind_DebugHook (void *, void *)
|
||
__attribute__ ((__noinline__, __used__, __noclone__));
|
||
|
||
/* This function is called during unwinding. It is intended as a hook
|
||
for a debugger to intercept exceptions. CFA is the CFA of the
|
||
target frame. HANDLER is the PC to which control will be
|
||
transferred. */
|
||
static void
|
||
_Unwind_DebugHook (void *cfa __attribute__ ((__unused__)),
|
||
void *handler __attribute__ ((__unused__)))
|
||
{
|
||
/* We only want to use stap probes starting with v3. Earlier
|
||
versions added too much startup cost. */
|
||
#if defined (HAVE_SYS_SDT_H) && defined (STAP_PROBE2) && _SDT_NOTE_TYPE >= 3
|
||
STAP_PROBE2 (libgcc, unwind, cfa, handler);
|
||
#else
|
||
asm ("");
|
||
#endif
|
||
}
|
||
|
||
/* Install TARGET into CURRENT so that we can return to it. This is a
|
||
macro because __builtin_eh_return must be invoked in the context of
|
||
our caller. */
|
||
|
||
#define uw_install_context(CURRENT, TARGET) \
|
||
do \
|
||
{ \
|
||
long offset = uw_install_context_1 ((CURRENT), (TARGET)); \
|
||
void *handler = __builtin_frob_return_addr ((TARGET)->ra); \
|
||
_Unwind_DebugHook ((TARGET)->cfa, handler); \
|
||
__builtin_eh_return (offset, handler); \
|
||
} \
|
||
while (0)
|
||
|
||
static long
|
||
uw_install_context_1 (struct _Unwind_Context *current,
|
||
struct _Unwind_Context *target)
|
||
{
|
||
long i;
|
||
_Unwind_SpTmp sp_slot;
|
||
|
||
/* If the target frame does not have a saved stack pointer,
|
||
then set up the target's CFA. */
|
||
if (!_Unwind_GetGRPtr (target, __builtin_dwarf_sp_column ()))
|
||
_Unwind_SetSpColumn (target, target->cfa, &sp_slot);
|
||
|
||
for (i = 0; i < DWARF_FRAME_REGISTERS; ++i)
|
||
{
|
||
void *c = (void *) (_Unwind_Internal_Ptr) current->reg[i];
|
||
void *t = (void *) (_Unwind_Internal_Ptr)target->reg[i];
|
||
|
||
gcc_assert (current->by_value[i] == 0);
|
||
if (target->by_value[i] && c)
|
||
{
|
||
_Unwind_Word w;
|
||
_Unwind_Ptr p;
|
||
if (dwarf_reg_size_table[i] == sizeof (_Unwind_Word))
|
||
{
|
||
w = (_Unwind_Internal_Ptr) t;
|
||
memcpy (c, &w, sizeof (_Unwind_Word));
|
||
}
|
||
else
|
||
{
|
||
gcc_assert (dwarf_reg_size_table[i] == sizeof (_Unwind_Ptr));
|
||
p = (_Unwind_Internal_Ptr) t;
|
||
memcpy (c, &p, sizeof (_Unwind_Ptr));
|
||
}
|
||
}
|
||
else if (t && c && t != c)
|
||
memcpy (c, t, dwarf_reg_size_table[i]);
|
||
}
|
||
|
||
/* If the current frame doesn't have a saved stack pointer, then we
|
||
need to rely on EH_RETURN_STACKADJ_RTX to get our target stack
|
||
pointer value reloaded. */
|
||
if (!_Unwind_GetGRPtr (current, __builtin_dwarf_sp_column ()))
|
||
{
|
||
void *target_cfa;
|
||
|
||
target_cfa = _Unwind_GetPtr (target, __builtin_dwarf_sp_column ());
|
||
|
||
/* We adjust SP by the difference between CURRENT and TARGET's CFA. */
|
||
if (STACK_GROWS_DOWNWARD)
|
||
return target_cfa - current->cfa + target->args_size;
|
||
else
|
||
return current->cfa - target_cfa - target->args_size;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
static inline _Unwind_Ptr
|
||
uw_identify_context (struct _Unwind_Context *context)
|
||
{
|
||
/* The CFA is not sufficient to disambiguate the context of a function
|
||
interrupted by a signal before establishing its frame and the context
|
||
of the signal itself. */
|
||
if (STACK_GROWS_DOWNWARD)
|
||
return _Unwind_GetCFA (context) - _Unwind_IsSignalFrame (context);
|
||
else
|
||
return _Unwind_GetCFA (context) + _Unwind_IsSignalFrame (context);
|
||
}
|
||
|
||
|
||
#include "unwind.inc"
|
||
|
||
#if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS)
|
||
alias (_Unwind_Backtrace);
|
||
alias (_Unwind_DeleteException);
|
||
alias (_Unwind_FindEnclosingFunction);
|
||
alias (_Unwind_ForcedUnwind);
|
||
alias (_Unwind_GetDataRelBase);
|
||
alias (_Unwind_GetTextRelBase);
|
||
alias (_Unwind_GetCFA);
|
||
alias (_Unwind_GetGR);
|
||
alias (_Unwind_GetIP);
|
||
alias (_Unwind_GetLanguageSpecificData);
|
||
alias (_Unwind_GetRegionStart);
|
||
alias (_Unwind_RaiseException);
|
||
alias (_Unwind_Resume);
|
||
alias (_Unwind_Resume_or_Rethrow);
|
||
alias (_Unwind_SetGR);
|
||
alias (_Unwind_SetIP);
|
||
#endif
|
||
|
||
#endif /* !USING_SJLJ_EXCEPTIONS */
|