Breakpad Linux dumper: Add support for dumping DWARF CFI as STACK CFI records.

Define a new DWARF parser class, dwarf2reader::CallFrameInfo.

Extend google_breakpad::Module to store and write out 'STACK CFI' records.

Define a new google_breakpad::DwarfCFIToModule class, to accept DWARF
CFI data from the parser and populate a Module with the equivalent
STACK CFI records.

Extend the Linux symbol dumping tool, dump_syms, to use
dwarf2reader::CallFrameInfo, google_breakpad::DwarfCFIToModule, and
google_breakpad::Module to extract DWARF CFI from the executable or
shared library files and write it to the Breakpad symbol file.

Define CFISection, a new class derived from TestAssembler::Section,
for use in creating DWARF CFI data for test cases.

a=jimblandy, r=nealsid


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@550 4c0a9323-5329-0410-9bdc-e9ce6186880e

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_