The Tor Browser: toolkit/crashreporter/google-breakpad/src/common/dwarf/cfi

toolkit/crashreporter/google-breakpad/src/common/dwarf/cfi_assembler.h@129ffea94266 (annotated)

toolkit/crashreporter/google-breakpad/src/common/dwarf/cfi_assembler.h

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 // -*- 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 "common/dwarf/dwarf2enums.h"
 #include "common/test_assembler.h"
 #include "common/using_std_string.h"
 #include "google_breakpad/common/breakpad_types.h"
 namespace google_breakpad {
 using dwarf2reader::DwarfPointerEncoding;
 using google_breakpad::test_assembler::Endianness;
 using google_breakpad::test_assembler::Label;
 using google_breakpad::test_assembler::Section;
 class CFISection: public Section {
  public:
   // CFI augmentation strings beginning with 'z', defined by the
   // Linux/IA-64 C++ ABI, can specify interesting encodings for
   // addresses appearing in FDE headers and call frame instructions (and
   // for additional fields whose presence the augmentation string
   // specifies). In particular, pointers can be specified to be relative
   // to various base address: the start of the .text section, the
   // location holding the address itself, and so on. These allow the
   // frame data to be position-independent even when they live in
   // write-protected pages. These variants are specified at the
   // following two URLs:
   //
   // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/dwarfext.html
   // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
   //
   // CFISection leaves the production of well-formed 'z'-augmented CIEs and
   // FDEs to the user, but does provide EncodedPointer, to emit
   // properly-encoded addresses for a given pointer encoding.
   // EncodedPointer uses an instance of this structure to find the base
   // addresses it should use; you can establish a default for all encoded
   // pointers appended to this section with SetEncodedPointerBases.
   struct EncodedPointerBases {
     EncodedPointerBases() : cfi(), text(), data() { }
     // The starting address of this CFI section in memory, for
     // DW_EH_PE_pcrel. DW_EH_PE_pcrel pointers may only be used in data
     // that has is loaded into the program's address space.
     uint64_t cfi;
     // The starting address of this file's .text section, for DW_EH_PE_textrel.
     uint64_t text;
     // The starting address of this file's .got or .eh_frame_hdr section,
     // for DW_EH_PE_datarel.
     uint64_t data;
   };
   // Create a CFISection whose endianness is ENDIANNESS, and where
   // machine addresses are ADDRESS_SIZE bytes long. If EH_FRAME is
   // true, use the .eh_frame format, as described by the Linux
   // Standards Base Core Specification, instead of the DWARF CFI
   // format.
   CFISection(Endianness endianness, size_t address_size,
              bool eh_frame = false)
       : Section(endianness), address_size_(address_size), eh_frame_(eh_frame),
         pointer_encoding_(dwarf2reader::DW_EH_PE_absptr),
         encoded_pointer_bases_(), entry_length_(NULL), in_fde_(false) {
     // 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_; }
   // Return true if this CFISection uses the .eh_frame format, or
   // false if it contains ordinary DWARF CFI data.
   bool ContainsEHFrame() const { return eh_frame_; }
   // Use ENCODING for pointers in calls to FDEHeader and EncodedPointer.
   void SetPointerEncoding(DwarfPointerEncoding encoding) {
     pointer_encoding_ = encoding;
   }
   // Use the addresses in BASES as the base addresses for encoded
   // pointers in subsequent calls to FDEHeader or EncodedPointer.
   // This function makes a copy of BASES.
   void SetEncodedPointerBases(const EncodedPointerBases &bases) {
     encoded_pointer_bases_ = bases;
   }
   // 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(uint64_t code_alignment_factor,
                         int data_alignment_factor,
                         unsigned return_address_register,
                         uint8_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,
                         uint64_t initial_location,
                         uint64_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;
   }
   // Append ADDRESS to this section, in the appropriate size and
   // endianness. Return a reference to this section.
   CFISection &Address(uint64_t address) {
     Section::Append(endianness(), address_size_, address);
     return *this;
   }
   CFISection &Address(Label address) {
     Section::Append(endianness(), address_size_, address);
     return *this;
   }
   // Append ADDRESS to this section, using ENCODING and BASES. ENCODING
   // defaults to this section's default encoding, established by
   // SetPointerEncoding. BASES defaults to this section's bases, set by
   // SetEncodedPointerBases. If the DW_EH_PE_indirect bit is set in the
   // encoding, assume that ADDRESS is where the true address is stored.
   // Return a reference to this section.
   //
   // (C++ doesn't let me use default arguments here, because I want to
   // refer to members of *this in the default argument expression.)
   CFISection &EncodedPointer(uint64_t address) {
     return EncodedPointer(address, pointer_encoding_, encoded_pointer_bases_);
   }
   CFISection &EncodedPointer(uint64_t address, DwarfPointerEncoding encoding) {
     return EncodedPointer(address, encoding, encoded_pointer_bases_);
   }
   CFISection &EncodedPointer(uint64_t address, DwarfPointerEncoding encoding,
                              const EncodedPointerBases &bases);
   // Restate some member functions, to keep chaining working nicely.
   CFISection &Mark(Label *label)   { Section::Mark(label); return *this; }
   CFISection &D8(uint8_t v)       { Section::D8(v);       return *this; }
   CFISection &D16(uint16_t v)     { Section::D16(v);      return *this; }
   CFISection &D16(Label v)         { Section::D16(v);      return *this; }
   CFISection &D32(uint32_t v)     { Section::D32(v);      return *this; }
   CFISection &D32(const Label &v)  { Section::D32(v);      return *this; }
   CFISection &D64(uint64_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(uint64_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;
   };
   // Constants used in CFI/.eh_frame data:
   // If the first four bytes of an "initial length" are this constant, then
   // the data uses the 64-bit DWARF format, and the length itself is the
   // subsequent eight bytes.
   static const uint32_t kDwarf64InitialLengthMarker = 0xffffffffU;
   // The CIE identifier for 32- and 64-bit DWARF CFI and .eh_frame data.
   static const uint32_t kDwarf32CIEIdentifier = ~(uint32_t)0;
   static const uint64_t kDwarf64CIEIdentifier = ~(uint64_t)0;
   static const uint32_t kEHFrame32CIEIdentifier = 0;
   static const uint64_t kEHFrame64CIEIdentifier = 0;
   // The size of a machine address for the data in this section.
   size_t address_size_;
   // If true, we are generating a Linux .eh_frame section, instead of
   // a standard DWARF .debug_frame section.
   bool eh_frame_;
   // The encoding to use for FDE pointers.
   DwarfPointerEncoding pointer_encoding_;
   // The base addresses to use when emitting encoded pointers.
   EncodedPointerBases encoded_pointer_bases_;
   // 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_;
   // True if we are currently emitting an FDE --- that is, we have
   // called FDEHeader but have not yet called FinishEntry.
   bool in_fde_;
   // If in_fde_ is true, this is its starting address. We use this for
   // emitting DW_EH_PE_funcrel pointers.
   uint64_t fde_start_address_;
 };
 }  // namespace google_breakpad
 #endif  // PROCESSOR_CFI_ASSEMBLER_H_

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toolkit/crashreporter/google-breakpad/src/common/dwarf/cfi_assembler.h@129ffea94266 (annotated)

toolkit/crashreporter/google-breakpad/src/common/dwarf/cfi_assembler.h