dwarf2reader_test_common.h

// -*- mode: c++ -*-

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// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>

// dwarf2reader_test_common.h: Define TestCompilationUnit and
// TestAbbrevTable, classes for creating properly (and improperly)
// formatted DWARF compilation unit data for unit tests.

#ifndef COMMON_DWARF_DWARF2READER_TEST_COMMON_H__
#define COMMON_DWARF_DWARF2READER_TEST_COMMON_H__

#include "common/test_assembler.h"
#include "common/dwarf/dwarf2enums.h"

// A subclass of test_assembler::Section, specialized for constructing
// DWARF compilation units.
class TestCompilationUnit: public google_breakpad::test_assembler::Section {
 public:
  typedef dwarf2reader::DwarfTag DwarfTag;
  typedef dwarf2reader::DwarfAttribute DwarfAttribute;
  typedef dwarf2reader::DwarfForm DwarfForm;
  typedef google_breakpad::test_assembler::Label Label;

  // Set the section's DWARF format size (the 32-bit DWARF format or the
  // 64-bit DWARF format, for lengths and section offsets --- not the
  // address size) to format_size.
  void set_format_size(size_t format_size) {
    assert(format_size == 4 || format_size == 8);
    format_size_ = format_size;
  }
    
  // Append a DWARF section offset value, of the appropriate size for this
  // compilation unit.
  template<typename T>
  void SectionOffset(T offset) {
    if (format_size_ == 4)
      D32(offset);
    else
      D64(offset);
  }

  // Append a DWARF compilation unit header to the section, with the given
  // DWARF version, abbrev table offset, and address size.
  TestCompilationUnit &Header(int version, const Label &abbrev_offset,
                              size_t address_size) {
    if (format_size_ == 4) {
      D32(length_);
    } else {
      D32(0xffffffff);
      D64(length_);
    }
    post_length_offset_ = Size();
    D16(version);
    SectionOffset(abbrev_offset);
    D8(address_size);
    return *this;
  }

  // Mark the end of this header's DIEs.
  TestCompilationUnit &Finish() {
    length_ = Size() - post_length_offset_;
    return *this;
  }

 private:
  // The DWARF format size for this compilation unit.
  size_t format_size_;

  // The offset of the point in the compilation unit header immediately
  // after the initial length field.
  uint64_t post_length_offset_;

  // The length of the compilation unit, not including the initial length field.
  Label length_;
};

// A subclass of test_assembler::Section specialized for constructing DWARF
// abbreviation tables.
class TestAbbrevTable: public google_breakpad::test_assembler::Section {
 public:
  typedef dwarf2reader::DwarfTag DwarfTag;
  typedef dwarf2reader::DwarfAttribute DwarfAttribute;
  typedef dwarf2reader::DwarfForm DwarfForm;
  typedef dwarf2reader::DwarfHasChild DwarfHasChild;
  typedef google_breakpad::test_assembler::Label Label;

  // Start a new abbreviation table entry for abbreviation code |code|,
  // encoding a DIE whose tag is |tag|, and which has children if and only
  // if |has_children| is true.
  TestAbbrevTable &Abbrev(int code, DwarfTag tag, DwarfHasChild has_children) {
    assert(code != 0);
    ULEB128(code);
    ULEB128(static_cast<unsigned>(tag));
    D8(static_cast<unsigned>(has_children));
    return *this;
  };

  // Add an attribute to the current abbreviation code whose name is |name|
  // and whose form is |form|.
  TestAbbrevTable &Attribute(DwarfAttribute name, DwarfForm form) {
    ULEB128(static_cast<unsigned>(name));
    ULEB128(static_cast<unsigned>(form));
    return *this;
  }

  // Finish the current abbreviation code.
  TestAbbrevTable &EndAbbrev() {
    ULEB128(0);
    ULEB128(0);
    return *this;
  }

  // Finish the current abbreviation table.
  TestAbbrevTable &EndTable() {
    ULEB128(0);
    return *this;
  }
};

#endif // COMMON_DWARF_DWARF2READER_TEST_COMMON_H__