src/common/language.h

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

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

// language.h: Define google_breakpad::Language. Instances of
// subclasses of this class provide language-appropriate operations
// for the Breakpad symbol dumper.

#ifndef COMMON_LINUX_LANGUAGE_H__
#define COMMON_LINUX_LANGUAGE_H__

#include <string>

#include "common/using_std_string.h"

namespace google_breakpad {

// An abstract base class for language-specific operations. We choose
// an instance of a subclass of this when we find the CU's language.
// This class's definitions are appropriate for CUs with no specified
// language.
class Language {
 public:
  // A base class destructor should be either public and virtual,
  // or protected and nonvirtual.
  virtual ~Language() {}

  // Return true if this language has functions to which we can assign
  // line numbers. (Debugging info for assembly language, for example,
  // can have source location information, but does not have functions
  // recorded using DW_TAG_subprogram DIEs.)
  virtual bool HasFunctions() const { return true; }

  // Construct a fully-qualified, language-appropriate form of NAME,
  // given that PARENT_NAME is the name of the construct enclosing
  // NAME. If PARENT_NAME is the empty string, then NAME is a
  // top-level name.
  //
  // This API sort of assumes that a fully-qualified name is always
  // some simple textual composition of the unqualified name and its
  // parent's name, and that we don't need to know anything else about
  // the parent or the child (say, their DIEs' tags) to do the job.
  // This is true for the languages we support at the moment, and
  // keeps things concrete. Perhaps a more refined operation would
  // take into account the parent and child DIE types, allow languages
  // to use their own data type for complex parent names, etc. But if
  // C++ doesn't need all that, who would?
  virtual string MakeQualifiedName (const string &parent_name,
                                    const string &name) const = 0;

  enum DemangleResult {
    // Demangling was not performed because it’s not appropriate to attempt.
    kDontDemangle = -1,

    kDemangleSuccess,
    kDemangleFailure,
  };

  // Wraps abi::__cxa_demangle() or similar for languages where appropriate.
  virtual DemangleResult DemangleName(const string& mangled,
                                      string* demangled) const {
    demangled->clear();
    return kDontDemangle;
  }

  // Instances for specific languages.
  static const Language * const CPlusPlus,
                        * const Java,
                        * const Swift,
                        * const Rust,
                        * const Assembler;
};

} // namespace google_breakpad

#endif  // COMMON_LINUX_LANGUAGE_H__