1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/toolkit/crashreporter/google-breakpad/src/common/dwarf/cfi_assembler.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,198 @@
1.4 +// Copyright (c) 2010, Google Inc.
1.5 +// All rights reserved.
1.6 +//
1.7 +// Redistribution and use in source and binary forms, with or without
1.8 +// modification, are permitted provided that the following conditions are
1.9 +// met:
1.10 +//
1.11 +// * Redistributions of source code must retain the above copyright
1.12 +// notice, this list of conditions and the following disclaimer.
1.13 +// * Redistributions in binary form must reproduce the above
1.14 +// copyright notice, this list of conditions and the following disclaimer
1.15 +// in the documentation and/or other materials provided with the
1.16 +// distribution.
1.17 +// * Neither the name of Google Inc. nor the names of its
1.18 +// contributors may be used to endorse or promote products derived from
1.19 +// this software without specific prior written permission.
1.20 +//
1.21 +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.22 +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.23 +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.24 +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1.25 +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.26 +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.27 +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.28 +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.29 +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.30 +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.31 +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.32 +
1.33 +// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
1.34 +
1.35 +// cfi_assembler.cc: Implementation of google_breakpad::CFISection class.
1.36 +// See cfi_assembler.h for details.
1.37 +
1.38 +#include "common/dwarf/cfi_assembler.h"
1.39 +
1.40 +#include <assert.h>
1.41 +#include <stdlib.h>
1.42 +
1.43 +namespace google_breakpad {
1.44 +
1.45 +using dwarf2reader::DwarfPointerEncoding;
1.46 +
1.47 +CFISection &CFISection::CIEHeader(uint64_t code_alignment_factor,
1.48 + int data_alignment_factor,
1.49 + unsigned return_address_register,
1.50 + uint8_t version,
1.51 + const string &augmentation,
1.52 + bool dwarf64) {
1.53 + assert(!entry_length_);
1.54 + entry_length_ = new PendingLength();
1.55 + in_fde_ = false;
1.56 +
1.57 + if (dwarf64) {
1.58 + D32(kDwarf64InitialLengthMarker);
1.59 + D64(entry_length_->length);
1.60 + entry_length_->start = Here();
1.61 + D64(eh_frame_ ? kEHFrame64CIEIdentifier : kDwarf64CIEIdentifier);
1.62 + } else {
1.63 + D32(entry_length_->length);
1.64 + entry_length_->start = Here();
1.65 + D32(eh_frame_ ? kEHFrame32CIEIdentifier : kDwarf32CIEIdentifier);
1.66 + }
1.67 + D8(version);
1.68 + AppendCString(augmentation);
1.69 + ULEB128(code_alignment_factor);
1.70 + LEB128(data_alignment_factor);
1.71 + if (version == 1)
1.72 + D8(return_address_register);
1.73 + else
1.74 + ULEB128(return_address_register);
1.75 + return *this;
1.76 +}
1.77 +
1.78 +CFISection &CFISection::FDEHeader(Label cie_pointer,
1.79 + uint64_t initial_location,
1.80 + uint64_t address_range,
1.81 + bool dwarf64) {
1.82 + assert(!entry_length_);
1.83 + entry_length_ = new PendingLength();
1.84 + in_fde_ = true;
1.85 + fde_start_address_ = initial_location;
1.86 +
1.87 + if (dwarf64) {
1.88 + D32(0xffffffff);
1.89 + D64(entry_length_->length);
1.90 + entry_length_->start = Here();
1.91 + if (eh_frame_)
1.92 + D64(Here() - cie_pointer);
1.93 + else
1.94 + D64(cie_pointer);
1.95 + } else {
1.96 + D32(entry_length_->length);
1.97 + entry_length_->start = Here();
1.98 + if (eh_frame_)
1.99 + D32(Here() - cie_pointer);
1.100 + else
1.101 + D32(cie_pointer);
1.102 + }
1.103 + EncodedPointer(initial_location);
1.104 + // The FDE length in an .eh_frame section uses the same encoding as the
1.105 + // initial location, but ignores the base address (selected by the upper
1.106 + // nybble of the encoding), as it's a length, not an address that can be
1.107 + // made relative.
1.108 + EncodedPointer(address_range,
1.109 + DwarfPointerEncoding(pointer_encoding_ & 0x0f));
1.110 + return *this;
1.111 +}
1.112 +
1.113 +CFISection &CFISection::FinishEntry() {
1.114 + assert(entry_length_);
1.115 + Align(address_size_, dwarf2reader::DW_CFA_nop);
1.116 + entry_length_->length = Here() - entry_length_->start;
1.117 + delete entry_length_;
1.118 + entry_length_ = NULL;
1.119 + in_fde_ = false;
1.120 + return *this;
1.121 +}
1.122 +
1.123 +CFISection &CFISection::EncodedPointer(uint64_t address,
1.124 + DwarfPointerEncoding encoding,
1.125 + const EncodedPointerBases &bases) {
1.126 + // Omitted data is extremely easy to emit.
1.127 + if (encoding == dwarf2reader::DW_EH_PE_omit)
1.128 + return *this;
1.129 +
1.130 + // If (encoding & dwarf2reader::DW_EH_PE_indirect) != 0, then we assume
1.131 + // that ADDRESS is the address at which the pointer is stored --- in
1.132 + // other words, that bit has no effect on how we write the pointer.
1.133 + encoding = DwarfPointerEncoding(encoding & ~dwarf2reader::DW_EH_PE_indirect);
1.134 +
1.135 + // Find the base address to which this pointer is relative. The upper
1.136 + // nybble of the encoding specifies this.
1.137 + uint64_t base;
1.138 + switch (encoding & 0xf0) {
1.139 + case dwarf2reader::DW_EH_PE_absptr: base = 0; break;
1.140 + case dwarf2reader::DW_EH_PE_pcrel: base = bases.cfi + Size(); break;
1.141 + case dwarf2reader::DW_EH_PE_textrel: base = bases.text; break;
1.142 + case dwarf2reader::DW_EH_PE_datarel: base = bases.data; break;
1.143 + case dwarf2reader::DW_EH_PE_funcrel: base = fde_start_address_; break;
1.144 + case dwarf2reader::DW_EH_PE_aligned: base = 0; break;
1.145 + default: abort();
1.146 + };
1.147 +
1.148 + // Make ADDRESS relative. Yes, this is appropriate even for "absptr"
1.149 + // values; see gcc/unwind-pe.h.
1.150 + address -= base;
1.151 +
1.152 + // Align the pointer, if required.
1.153 + if ((encoding & 0xf0) == dwarf2reader::DW_EH_PE_aligned)
1.154 + Align(AddressSize());
1.155 +
1.156 + // Append ADDRESS to this section in the appropriate form. For the
1.157 + // fixed-width forms, we don't need to differentiate between signed and
1.158 + // unsigned encodings, because ADDRESS has already been extended to 64
1.159 + // bits before it was passed to us.
1.160 + switch (encoding & 0x0f) {
1.161 + case dwarf2reader::DW_EH_PE_absptr:
1.162 + Address(address);
1.163 + break;
1.164 +
1.165 + case dwarf2reader::DW_EH_PE_uleb128:
1.166 + ULEB128(address);
1.167 + break;
1.168 +
1.169 + case dwarf2reader::DW_EH_PE_sleb128:
1.170 + LEB128(address);
1.171 + break;
1.172 +
1.173 + case dwarf2reader::DW_EH_PE_udata2:
1.174 + case dwarf2reader::DW_EH_PE_sdata2:
1.175 + D16(address);
1.176 + break;
1.177 +
1.178 + case dwarf2reader::DW_EH_PE_udata4:
1.179 + case dwarf2reader::DW_EH_PE_sdata4:
1.180 + D32(address);
1.181 + break;
1.182 +
1.183 + case dwarf2reader::DW_EH_PE_udata8:
1.184 + case dwarf2reader::DW_EH_PE_sdata8:
1.185 + D64(address);
1.186 + break;
1.187 +
1.188 + default:
1.189 + abort();
1.190 + }
1.191 +
1.192 + return *this;
1.193 +};
1.194 +
1.195 +const uint32_t CFISection::kDwarf64InitialLengthMarker;
1.196 +const uint32_t CFISection::kDwarf32CIEIdentifier;
1.197 +const uint64_t CFISection::kDwarf64CIEIdentifier;
1.198 +const uint32_t CFISection::kEHFrame32CIEIdentifier;
1.199 +const uint64_t CFISection::kEHFrame64CIEIdentifier;
1.200 +
1.201 +} // namespace google_breakpad
