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Diffstat (limited to 'src/common/dwarf/cfi_assembler.h')
| -rw-r--r-- | src/common/dwarf/cfi_assembler.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/common/dwarf/cfi_assembler.h b/src/common/dwarf/cfi_assembler.h new file mode 100644 index 00000000..449a8078 --- /dev/null +++ b/src/common/dwarf/cfi_assembler.h @@ -0,0 +1,149 @@ +// -*- mode: C++ -*- + +// 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.h: Define CFISection, a class for creating properly +// (and improperly) formatted DWARF CFI data for unit tests. + +#ifndef PROCESSOR_CFI_ASSEMBLER_H_ +#define PROCESSOR_CFI_ASSEMBLER_H_ + +#include <string> + +#include "google_breakpad/common/breakpad_types.h" +#include "processor/test_assembler.h" + +namespace google_breakpad { + +using google_breakpad::TestAssembler::Endianness; +using google_breakpad::TestAssembler::Label; +using google_breakpad::TestAssembler::Section; +using std::string; + +class CFISection: public Section { + public: + // Create a CFISection whose endianness is ENDIANNESS, and where + // machine addresses are ADDRESS_SIZE bytes long. + CFISection(Endianness endianness, size_t address_size) + : Section(endianness), address_size_(address_size), + entry_length_(NULL) { + // The 'start', 'Here', and 'Mark' members of a CFISection all refer + // to section offsets. + start() = 0; + } + + // Return this CFISection's address size. + size_t AddressSize() const { return address_size_; } + + // Append a Common Information Entry header to this section with the + // given values. If dwarf64 is true, use the 64-bit DWARF initial + // length format for the CIE's initial length. Return a reference to + // this section. You should call FinishEntry after writing the last + // instruction for the CIE. + // + // Before calling this function, you will typically want to use Mark + // or Here to make a label to pass to FDEHeader that refers to this + // CIE's position in the section. + CFISection &CIEHeader(u_int64_t code_alignment_factor, + int data_alignment_factor, + unsigned return_address_register, + u_int8_t version = 3, + const string &augmentation = "", + bool dwarf64 = false); + + // Append a Frame Description Entry header to this section with the + // given values. If dwarf64 is true, use the 64-bit DWARF initial + // length format for the CIE's initial length. Return a reference to + // this section. You should call FinishEntry after writing the last + // instruction for the CIE. + // + // This function doesn't support entries that are longer than + // 0xffffff00 bytes. (The "initial length" is always a 32-bit + // value.) Nor does it support .debug_frame sections longer than + // 0xffffff00 bytes. + CFISection &FDEHeader(Label cie_pointer, + u_int64_t initial_location, + u_int64_t address_range, + bool dwarf64 = false); + + // Note the current position as the end of the last CIE or FDE we + // started, after padding with DW_CFA_nops for alignment. This + // defines the label representing the entry's length, cited in the + // entry's header. Return a reference to this section. + CFISection &FinishEntry(); + + // Append the contents of BLOCK as a DW_FORM_block value: an + // unsigned LEB128 length, followed by that many bytes of data. + CFISection &Block(const string &block) { + ULEB128(block.size()); + Append(block); + return *this; + } + + // Restate some member functions, to keep chaining working nicely. + CFISection &Mark(Label *label) { Section::Mark(label); return *this; } + CFISection &D8(u_int8_t v) { Section::D8(v); return *this; } + CFISection &D16(u_int16_t v) { Section::D16(v); return *this; } + CFISection &D16(Label v) { Section::D16(v); return *this; } + CFISection &D32(u_int32_t v) { Section::D32(v); return *this; } + CFISection &D32(const Label &v) { Section::D32(v); return *this; } + CFISection &D64(u_int64_t v) { Section::D64(v); return *this; } + CFISection &D64(const Label &v) { Section::D64(v); return *this; } + CFISection &LEB128(long long v) { Section::LEB128(v); return *this; } + CFISection &ULEB128(u_int64_t v) { Section::ULEB128(v); return *this; } + + private: + // A length value that we've appended to the section, but is not yet + // known. LENGTH is the appended value; START is a label referring + // to the start of the data whose length was cited. + struct PendingLength { + Label length; + Label start; + }; + + // The size of a machine address for the data in this section. + size_t address_size_; + + // The length value for the current entry. + // + // Oddly, this must be dynamically allocated. Labels never get new + // values; they only acquire constraints on the value they already + // have, or assert if you assign them something incompatible. So + // each header needs truly fresh Label objects to cite in their + // headers and track their positions. The alternative is explicit + // destructor invocation and a placement new. Ick. + PendingLength *entry_length_; +}; + +} // namespace google_breakpad + +#endif // PROCESSOR_CFI_ASSEMBLER_H_ |