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Diffstat (limited to 'sysdeps/generic/unwind-pe.h')
| -rw-r--r-- | sysdeps/generic/unwind-pe.h | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/sysdeps/generic/unwind-pe.h b/sysdeps/generic/unwind-pe.h new file mode 100644 index 0000000..e4a564e --- /dev/null +++ b/sysdeps/generic/unwind-pe.h @@ -0,0 +1,272 @@ +/* Exception handling and frame unwind runtime interface routines. + Copyright (C) 2001 Free Software Foundation, Inc. + + This file is part of GNU CC. + + GNU CC 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 2, or (at your option) + any later version. + + GNU CC 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. + + You should have received a copy of the GNU General Public License + along with GNU CC; see the file COPYING. If not, write to + the Free Software Foundation, 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* @@@ 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. */ + +/* 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 + +/* Pointer encodings, from dwarf2.h. */ +#define DW_EH_PE_absptr 0x00 +#define DW_EH_PE_omit 0xff + +#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 + +#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 + +#define DW_EH_PE_indirect 0x80 + + +/* 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. */ + +#ifndef _LIBC +static +#endif +unsigned int +size_of_encoded_value (unsigned char encoding) +#if defined(_LIBC) && !defined(NO_BASE_OF_ENCODED_VALUE) +; +#else +{ + if (encoding == DW_EH_PE_omit) + return 0; + + 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 (); +} +#endif + +#ifndef NO_BASE_OF_ENCODED_VALUE + +/* 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. */ + +static _Unwind_Ptr +base_of_encoded_value (unsigned char encoding, struct _Unwind_Context *context) +{ + if (encoding == DW_EH_PE_omit) + return 0; + + switch (encoding & 0x70) + { + case DW_EH_PE_absptr: + case DW_EH_PE_pcrel: + case DW_EH_PE_aligned: + return 0; + + 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 (); +} + +#endif + +/* 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. */ + +#ifndef _LIBC +static +#endif +const unsigned char * +read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base, + const unsigned char *p, _Unwind_Ptr *val) +#if defined(_LIBC) && !defined(NO_BASE_OF_ENCODED_VALUE) +; +#else +{ + 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__)); + + union unaligned *u = (union unaligned *) p; + _Unwind_Ptr result; + + if (encoding == DW_EH_PE_aligned) + { + _Unwind_Ptr a = (_Unwind_Ptr)p; + a = (a + sizeof (void *) - 1) & - sizeof(void *); + result = *(_Unwind_Ptr *) a; + p = (const unsigned char *)(a + sizeof (void *)); + } + else + { + switch (encoding & 0x0f) + { + case DW_EH_PE_absptr: + result = (_Unwind_Ptr) u->ptr; + p += sizeof (void *); + break; + + case DW_EH_PE_uleb128: + { + unsigned int shift = 0; + unsigned char byte; + + result = 0; + do + { + byte = *p++; + result |= (_Unwind_Ptr)(byte & 0x7f) << shift; + shift += 7; + } + while (byte & 0x80); + } + break; + + case DW_EH_PE_sleb128: + { + unsigned int shift = 0; + unsigned char byte; + + result = 0; + do + { + byte = *p++; + result |= (_Unwind_Ptr)(byte & 0x7f) << shift; + shift += 7; + } + while (byte & 0x80); + + if (shift < 8 * sizeof(result) && (byte & 0x40) != 0) + result |= -(1L << shift); + } + break; + + 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; + + 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; + + default: + __gxx_abort (); + } + + if (result != 0) + { + result += ((encoding & 0x70) == DW_EH_PE_pcrel + ? (_Unwind_Ptr)u : base); + if (encoding & DW_EH_PE_indirect) + result = *(_Unwind_Ptr *)result; + } + } + + *val = result; + return p; +} +#endif + +#ifndef NO_BASE_OF_ENCODED_VALUE + +/* Like read_encoded_value_with_base, but get the base from the context + rather than providing it directly. */ + +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); +} + +#endif + +/* Read an unsigned leb128 value from P, store the value in VAL, return + P incremented past the value. */ + +static inline const unsigned char * +read_uleb128 (const unsigned char *p, _Unwind_Ptr *val) +{ + return read_encoded_value_with_base (DW_EH_PE_uleb128, 0, p, val); +} + +/* Similar, but read a signed leb128 value. */ + +static inline const unsigned char * +read_sleb128 (const unsigned char *p, _Unwind_Ptr *val) +{ + return read_encoded_value_with_base (DW_EH_PE_sleb128, 0, p, val); +} |