0,0 → 1,289 |
/* Exception handling and frame unwind runtime interface routines. |
Copyright (C) 2001, 2002, 2003, 2004, 2008, 2009 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 |
under the terms of the GNU General Public License as published by |
the Free Software Foundation; either version 3, or (at your option) |
any later version. |
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GCC is distributed in the hope that it will be useful, but WITHOUT |
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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Under Section 7 of GPL version 3, you are granted additional |
permissions described in the GCC Runtime Library Exception, version |
3.1, as published by the Free Software Foundation. |
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You should have received a copy of the GNU General Public License and |
a copy of the GCC Runtime Library Exception along with this program; |
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
<http://www.gnu.org/licenses/>. */ |
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/* @@@ Really this should be out of line, but this also causes link |
compatibility problems with the base ABI. This is slightly better |
than duplicating code, however. */ |
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#ifndef GCC_UNWIND_PE_H |
#define GCC_UNWIND_PE_H |
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/* If using C++, references to abort have to be qualified with std::. */ |
#if __cplusplus |
#define __gxx_abort std::abort |
#else |
#define __gxx_abort abort |
#endif |
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/* Pointer encodings, from dwarf2.h. */ |
#define DW_EH_PE_absptr 0x00 |
#define DW_EH_PE_omit 0xff |
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#define DW_EH_PE_uleb128 0x01 |
#define DW_EH_PE_udata2 0x02 |
#define DW_EH_PE_udata4 0x03 |
#define DW_EH_PE_udata8 0x04 |
#define DW_EH_PE_sleb128 0x09 |
#define DW_EH_PE_sdata2 0x0A |
#define DW_EH_PE_sdata4 0x0B |
#define DW_EH_PE_sdata8 0x0C |
#define DW_EH_PE_signed 0x08 |
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#define DW_EH_PE_pcrel 0x10 |
#define DW_EH_PE_textrel 0x20 |
#define DW_EH_PE_datarel 0x30 |
#define DW_EH_PE_funcrel 0x40 |
#define DW_EH_PE_aligned 0x50 |
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#define DW_EH_PE_indirect 0x80 |
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#ifndef NO_SIZE_OF_ENCODED_VALUE |
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/* Given an encoding, return the number of bytes the format occupies. |
This is only defined for fixed-size encodings, and so does not |
include leb128. */ |
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static unsigned int |
size_of_encoded_value (unsigned char encoding) __attribute__ ((unused)); |
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static unsigned int |
size_of_encoded_value (unsigned char encoding) |
{ |
if (encoding == DW_EH_PE_omit) |
return 0; |
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switch (encoding & 0x07) |
{ |
case DW_EH_PE_absptr: |
return sizeof (void *); |
case DW_EH_PE_udata2: |
return 2; |
case DW_EH_PE_udata4: |
return 4; |
case DW_EH_PE_udata8: |
return 8; |
} |
__gxx_abort (); |
} |
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#endif |
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#ifndef NO_BASE_OF_ENCODED_VALUE |
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/* Given an encoding and an _Unwind_Context, return the base to which |
the encoding is relative. This base may then be passed to |
read_encoded_value_with_base for use when the _Unwind_Context is |
not available. */ |
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static _Unwind_Ptr |
base_of_encoded_value (unsigned char encoding, struct _Unwind_Context *context) |
{ |
if (encoding == DW_EH_PE_omit) |
return 0; |
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switch (encoding & 0x70) |
{ |
case DW_EH_PE_absptr: |
case DW_EH_PE_pcrel: |
case DW_EH_PE_aligned: |
return 0; |
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case DW_EH_PE_textrel: |
return _Unwind_GetTextRelBase (context); |
case DW_EH_PE_datarel: |
return _Unwind_GetDataRelBase (context); |
case DW_EH_PE_funcrel: |
return _Unwind_GetRegionStart (context); |
} |
__gxx_abort (); |
} |
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#endif |
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/* Read an unsigned leb128 value from P, store the value in VAL, return |
P incremented past the value. We assume that a word is large enough to |
hold any value so encoded; if it is smaller than a pointer on some target, |
pointers should not be leb128 encoded on that target. */ |
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static const unsigned char * |
read_uleb128 (const unsigned char *p, _uleb128_t *val) |
{ |
unsigned int shift = 0; |
unsigned char byte; |
_uleb128_t result; |
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result = 0; |
do |
{ |
byte = *p++; |
result |= ((_uleb128_t)byte & 0x7f) << shift; |
shift += 7; |
} |
while (byte & 0x80); |
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*val = result; |
return p; |
} |
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/* Similar, but read a signed leb128 value. */ |
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static const unsigned char * |
read_sleb128 (const unsigned char *p, _sleb128_t *val) |
{ |
unsigned int shift = 0; |
unsigned char byte; |
_uleb128_t result; |
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result = 0; |
do |
{ |
byte = *p++; |
result |= ((_uleb128_t)byte & 0x7f) << shift; |
shift += 7; |
} |
while (byte & 0x80); |
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/* Sign-extend a negative value. */ |
if (shift < 8 * sizeof(result) && (byte & 0x40) != 0) |
result |= -(((_uleb128_t)1L) << shift); |
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*val = (_sleb128_t) result; |
return p; |
} |
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/* Load an encoded value from memory at P. The value is returned in VAL; |
The function returns P incremented past the value. BASE is as given |
by base_of_encoded_value for this encoding in the appropriate context. */ |
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static const unsigned char * |
read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base, |
const unsigned char *p, _Unwind_Ptr *val) |
{ |
union unaligned |
{ |
void *ptr; |
unsigned u2 __attribute__ ((mode (HI))); |
unsigned u4 __attribute__ ((mode (SI))); |
unsigned u8 __attribute__ ((mode (DI))); |
signed s2 __attribute__ ((mode (HI))); |
signed s4 __attribute__ ((mode (SI))); |
signed s8 __attribute__ ((mode (DI))); |
} __attribute__((__packed__)); |
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const union unaligned *u = (const union unaligned *) p; |
_Unwind_Internal_Ptr result; |
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if (encoding == DW_EH_PE_aligned) |
{ |
_Unwind_Internal_Ptr a = (_Unwind_Internal_Ptr) p; |
a = (a + sizeof (void *) - 1) & - sizeof(void *); |
result = *(_Unwind_Internal_Ptr *) a; |
p = (const unsigned char *) (_Unwind_Internal_Ptr) (a + sizeof (void *)); |
} |
else |
{ |
switch (encoding & 0x0f) |
{ |
case DW_EH_PE_absptr: |
result = (_Unwind_Internal_Ptr) u->ptr; |
p += sizeof (void *); |
break; |
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case DW_EH_PE_uleb128: |
{ |
_uleb128_t tmp; |
p = read_uleb128 (p, &tmp); |
result = (_Unwind_Internal_Ptr) tmp; |
} |
break; |
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case DW_EH_PE_sleb128: |
{ |
_sleb128_t tmp; |
p = read_sleb128 (p, &tmp); |
result = (_Unwind_Internal_Ptr) tmp; |
} |
break; |
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case DW_EH_PE_udata2: |
result = u->u2; |
p += 2; |
break; |
case DW_EH_PE_udata4: |
result = u->u4; |
p += 4; |
break; |
case DW_EH_PE_udata8: |
result = u->u8; |
p += 8; |
break; |
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case DW_EH_PE_sdata2: |
result = u->s2; |
p += 2; |
break; |
case DW_EH_PE_sdata4: |
result = u->s4; |
p += 4; |
break; |
case DW_EH_PE_sdata8: |
result = u->s8; |
p += 8; |
break; |
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default: |
__gxx_abort (); |
} |
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if (result != 0) |
{ |
result += ((encoding & 0x70) == DW_EH_PE_pcrel |
? (_Unwind_Internal_Ptr) u : base); |
if (encoding & DW_EH_PE_indirect) |
result = *(_Unwind_Internal_Ptr *) result; |
} |
} |
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*val = result; |
return p; |
} |
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#ifndef NO_BASE_OF_ENCODED_VALUE |
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/* Like read_encoded_value_with_base, but get the base from the context |
rather than providing it directly. */ |
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static inline const unsigned char * |
read_encoded_value (struct _Unwind_Context *context, unsigned char encoding, |
const unsigned char *p, _Unwind_Ptr *val) |
{ |
return read_encoded_value_with_base (encoding, |
base_of_encoded_value (encoding, context), |
p, val); |
} |
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#endif |
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#endif /* unwind-pe.h */ |