// Copyright (C) 2012 The Android Open Source Project
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the project nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//
// This file implements the "Exception Handling APIs"
// http://www.codesourcery.com/public/cxx-abi/abi-eh.html
// http://www.intel.com/design/itanium/downloads/245358.htm
//
//===----------------------------------------------------------------------===//
#include <cstdlib>
#include <endian.h>
#include "dwarf_helper.h"
#if !defined(__BYTE_ORDER) || \
!defined(__LITTLE_ENDIAN) || !defined(__BIG_ENDIAN)
#error "Endianness testing macros are not defined"
#endif
#if __BYTE_ORDER != __LITTLE_ENDIAN && __BYTE_ORDER != __BIG_ENDIAN
#error "Unsupported endianness"
#endif
namespace __cxxabiv1 {
uintptr_t readULEB128(const uint8_t** data) {
uintptr_t result = 0;
uintptr_t shift = 0;
unsigned char byte;
const uint8_t *p = *data;
do {
byte = *p++;
result |= static_cast<uintptr_t>(byte & 0x7F) << shift;
shift += 7;
} while (byte & 0x80);
*data = p;
return result;
}
intptr_t readSLEB128(const uint8_t** data) {
uintptr_t result = 0;
uintptr_t shift = 0;
unsigned char byte;
const uint8_t *p = *data;
do {
byte = *p++;
result |= static_cast<uintptr_t>(byte & 0x7F) << shift;
shift += 7;
} while (byte & 0x80);
*data = p;
if ((byte & 0x40) && (shift < (sizeof(result) << 3))) {
result |= static_cast<uintptr_t>(~0) << shift;
}
return static_cast<intptr_t>(result);
}
static inline uint16_t readUData2(const uint8_t* data) {
#if __BYTE_ORDER == __LITTLE_ENDIAN
return ((static_cast<uint16_t>(data[0])) |
(static_cast<uint16_t>(data[1]) << 8));
#elif __BYTE_ORDER == __BIG_ENDIAN
return ((static_cast<uint16_t>(data[0]) << 8) |
(static_cast<uint16_t>(data[1])));
#endif
}
static inline uint32_t readUData4(const uint8_t* data) {
#if __BYTE_ORDER == __LITTLE_ENDIAN
return ((static_cast<uint32_t>(data[0])) |
(static_cast<uint32_t>(data[1]) << 8) |
(static_cast<uint32_t>(data[2]) << 16) |
(static_cast<uint32_t>(data[3]) << 24));
#elif __BYTE_ORDER == __BIG_ENDIAN
return ((static_cast<uint32_t>(data[0]) << 24) |
(static_cast<uint32_t>(data[1]) << 16) |
(static_cast<uint32_t>(data[2]) << 8) |
(static_cast<uint32_t>(data[3])));
#endif
}
static inline uint64_t readUData8(const uint8_t* data) {
#if __BYTE_ORDER == __LITTLE_ENDIAN
return ((static_cast<uint64_t>(data[0])) |
(static_cast<uint64_t>(data[1]) << 8) |
(static_cast<uint64_t>(data[2]) << 16) |
(static_cast<uint64_t>(data[3]) << 24) |
(static_cast<uint64_t>(data[4]) << 32) |
(static_cast<uint64_t>(data[5]) << 40) |
(static_cast<uint64_t>(data[6]) << 48) |
(static_cast<uint64_t>(data[7]) << 56));
#elif __BYTE_ORDER == __BIG_ENDIAN
return ((static_cast<uint64_t>(data[0]) << 56) |
(static_cast<uint64_t>(data[1]) << 48) |
(static_cast<uint64_t>(data[2]) << 40) |
(static_cast<uint64_t>(data[3]) << 32) |
(static_cast<uint64_t>(data[4]) << 24) |
(static_cast<uint64_t>(data[5]) << 16) |
(static_cast<uint64_t>(data[6]) << 8) |
(static_cast<uint64_t>(data[7])));
#endif
}
static inline uintptr_t readAbsPtr(const uint8_t* data) {
if (sizeof(uintptr_t) == 4) {
return static_cast<uintptr_t>(readUData4(data));
} else if (sizeof(uintptr_t) == 8) {
return static_cast<uintptr_t>(readUData8(data));
} else {
abort();
}
}
uintptr_t readEncodedPointer(const uint8_t** data,
uint8_t encoding) {
uintptr_t result = 0;
if (encoding == DW_EH_PE_omit) {
return result;
}
const uint8_t* p = *data;
switch (encoding & 0x0F) {
default:
abort();
break;
case DW_EH_PE_absptr:
result = readAbsPtr(p);
p += sizeof(uintptr_t);
break;
case DW_EH_PE_uleb128:
result = readULEB128(&p);
break;
case DW_EH_PE_sleb128:
result = static_cast<uintptr_t>(readSLEB128(&p));
break;
case DW_EH_PE_udata2:
result = readUData2(p);
p += sizeof(uint16_t);
break;
case DW_EH_PE_udata4:
result = readUData4(p);
p += sizeof(uint32_t);
break;
case DW_EH_PE_udata8:
result = static_cast<uintptr_t>(readUData8(p));
p += sizeof(uint64_t);
break;
case DW_EH_PE_sdata2:
result = static_cast<uintptr_t>(static_cast<int16_t>(readUData2(p)));
p += sizeof(int16_t);
break;
case DW_EH_PE_sdata4:
result = static_cast<uintptr_t>(static_cast<int32_t>(readUData4(p)));
p += sizeof(int32_t);
break;
case DW_EH_PE_sdata8:
result = static_cast<uintptr_t>(static_cast<int64_t>(readUData8(p)));
p += sizeof(int64_t);
break;
}
switch (encoding & 0x70) {
default:
abort();
break;
case DW_EH_PE_absptr:
break;
case DW_EH_PE_pcrel:
if (result) {
result += (uintptr_t)(*data);
}
break;
}
// finally, apply indirection
if (result && (encoding & DW_EH_PE_indirect)) {
result = *(reinterpret_cast<uintptr_t*>(result));
}
*data = p;
return result;
}
} // namespace __cxxabiv1