diff options
Diffstat (limited to '3rdParty/Breakpad/src/common/dwarf/cfi_assembler.cc')
-rw-r--r-- | 3rdParty/Breakpad/src/common/dwarf/cfi_assembler.cc | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/3rdParty/Breakpad/src/common/dwarf/cfi_assembler.cc b/3rdParty/Breakpad/src/common/dwarf/cfi_assembler.cc new file mode 100644 index 0000000..2dc2208 --- /dev/null +++ b/3rdParty/Breakpad/src/common/dwarf/cfi_assembler.cc @@ -0,0 +1,204 @@ +// Copyright (c) 2010, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * 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. +// * Neither the name of Google Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT +// OWNER 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. + +// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> + +// cfi_assembler.cc: Implementation of google_breakpad::CFISection class. +// See cfi_assembler.h for details. + +#include "common/dwarf/cfi_assembler.h" + +#include <assert.h> +#include <stdlib.h> + +namespace google_breakpad { + +using dwarf2reader::DwarfPointerEncoding; + +CFISection &CFISection::CIEHeader(uint64_t code_alignment_factor, + int data_alignment_factor, + unsigned return_address_register, + uint8_t version, + const string &augmentation, + bool dwarf64, + uint8_t address_size, + uint8_t segment_size) { + assert(!entry_length_); + entry_length_ = new PendingLength(); + in_fde_ = false; + + if (dwarf64) { + D32(kDwarf64InitialLengthMarker); + D64(entry_length_->length); + entry_length_->start = Here(); + D64(eh_frame_ ? kEHFrame64CIEIdentifier : kDwarf64CIEIdentifier); + } else { + D32(entry_length_->length); + entry_length_->start = Here(); + D32(eh_frame_ ? kEHFrame32CIEIdentifier : kDwarf32CIEIdentifier); + } + D8(version); + AppendCString(augmentation); + if (version >= 4) { + D8(address_size); + D8(segment_size); + } + ULEB128(code_alignment_factor); + LEB128(data_alignment_factor); + if (version == 1) + D8(return_address_register); + else + ULEB128(return_address_register); + return *this; +} + +CFISection &CFISection::FDEHeader(Label cie_pointer, + uint64_t initial_location, + uint64_t address_range, + bool dwarf64) { + assert(!entry_length_); + entry_length_ = new PendingLength(); + in_fde_ = true; + fde_start_address_ = initial_location; + + if (dwarf64) { + D32(0xffffffff); + D64(entry_length_->length); + entry_length_->start = Here(); + if (eh_frame_) + D64(Here() - cie_pointer); + else + D64(cie_pointer); + } else { + D32(entry_length_->length); + entry_length_->start = Here(); + if (eh_frame_) + D32(Here() - cie_pointer); + else + D32(cie_pointer); + } + EncodedPointer(initial_location); + // The FDE length in an .eh_frame section uses the same encoding as the + // initial location, but ignores the base address (selected by the upper + // nybble of the encoding), as it's a length, not an address that can be + // made relative. + EncodedPointer(address_range, + DwarfPointerEncoding(pointer_encoding_ & 0x0f)); + return *this; +} + +CFISection &CFISection::FinishEntry() { + assert(entry_length_); + Align(address_size_, dwarf2reader::DW_CFA_nop); + entry_length_->length = Here() - entry_length_->start; + delete entry_length_; + entry_length_ = NULL; + in_fde_ = false; + return *this; +} + +CFISection &CFISection::EncodedPointer(uint64_t address, + DwarfPointerEncoding encoding, + const EncodedPointerBases &bases) { + // Omitted data is extremely easy to emit. + if (encoding == dwarf2reader::DW_EH_PE_omit) + return *this; + + // If (encoding & dwarf2reader::DW_EH_PE_indirect) != 0, then we assume + // that ADDRESS is the address at which the pointer is stored --- in + // other words, that bit has no effect on how we write the pointer. + encoding = DwarfPointerEncoding(encoding & ~dwarf2reader::DW_EH_PE_indirect); + + // Find the base address to which this pointer is relative. The upper + // nybble of the encoding specifies this. + uint64_t base; + switch (encoding & 0xf0) { + case dwarf2reader::DW_EH_PE_absptr: base = 0; break; + case dwarf2reader::DW_EH_PE_pcrel: base = bases.cfi + Size(); break; + case dwarf2reader::DW_EH_PE_textrel: base = bases.text; break; + case dwarf2reader::DW_EH_PE_datarel: base = bases.data; break; + case dwarf2reader::DW_EH_PE_funcrel: base = fde_start_address_; break; + case dwarf2reader::DW_EH_PE_aligned: base = 0; break; + default: abort(); + }; + + // Make ADDRESS relative. Yes, this is appropriate even for "absptr" + // values; see gcc/unwind-pe.h. + address -= base; + + // Align the pointer, if required. + if ((encoding & 0xf0) == dwarf2reader::DW_EH_PE_aligned) + Align(AddressSize()); + + // Append ADDRESS to this section in the appropriate form. For the + // fixed-width forms, we don't need to differentiate between signed and + // unsigned encodings, because ADDRESS has already been extended to 64 + // bits before it was passed to us. + switch (encoding & 0x0f) { + case dwarf2reader::DW_EH_PE_absptr: + Address(address); + break; + + case dwarf2reader::DW_EH_PE_uleb128: + ULEB128(address); + break; + + case dwarf2reader::DW_EH_PE_sleb128: + LEB128(address); + break; + + case dwarf2reader::DW_EH_PE_udata2: + case dwarf2reader::DW_EH_PE_sdata2: + D16(address); + break; + + case dwarf2reader::DW_EH_PE_udata4: + case dwarf2reader::DW_EH_PE_sdata4: + D32(address); + break; + + case dwarf2reader::DW_EH_PE_udata8: + case dwarf2reader::DW_EH_PE_sdata8: + D64(address); + break; + + default: + abort(); + } + + return *this; +}; + +const uint32_t CFISection::kDwarf64InitialLengthMarker; +const uint32_t CFISection::kDwarf32CIEIdentifier; +const uint64_t CFISection::kDwarf64CIEIdentifier; +const uint32_t CFISection::kEHFrame32CIEIdentifier; +const uint64_t CFISection::kEHFrame64CIEIdentifier; + +} // namespace google_breakpad |