The Tor Browser: toolkit/crashreporter/breakpad-patches/08-dwarf2reader-dynamic-cast.patch@129ffea94266 (annotated)

toolkit/crashreporter/breakpad-patches/08-dwarf2reader-dynamic-cast.patch@129ffea94266 (annotated)

toolkit/crashreporter/breakpad-patches/08-dwarf2reader-dynamic-cast.patch

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.

 # HG changeset patch
 # User Ted Mielczarek <ted@mielczarek.org>
 # Date 1362600444 18000
 # Node ID 0eb3c7ba8a38a269ab975eff3f95a1a5d5d937b9
 # Parent  6b68e82037b8322fb392cea369d517aeeaaee9d3
 Stop using dynamic_cast in dwarf2reader
 Patch by Julian Seward <jseward@acm.org>, R=ted
 diff --git a/src/common/dwarf/dwarf2reader.cc b/src/common/dwarf/dwarf2reader.cc
 --- a/src/common/dwarf/dwarf2reader.cc
 +++ b/src/common/dwarf/dwarf2reader.cc
@@ -887,68 +887,80 @@
    // If this is a base+offset rule, change its base register to REG.
    // Otherwise, do nothing. (Ugly, but required for DW_CFA_def_cfa_register.)
    virtual void SetBaseRegister(unsigned reg) { }
    // If this is a base+offset rule, change its offset to OFFSET. Otherwise,
    // do nothing. (Ugly, but required for DW_CFA_def_cfa_offset.)
    virtual void SetOffset(long long offset) { }
 +
 +  // A RTTI workaround, to make it possible to implement equality
 +  // comparisons on classes derived from this one.
 +  enum CFIRTag {
 +    CFIR_UNDEFINED_RULE,
 +    CFIR_SAME_VALUE_RULE,
 +    CFIR_OFFSET_RULE,
 +    CFIR_VAL_OFFSET_RULE,
 +    CFIR_REGISTER_RULE,
 +    CFIR_EXPRESSION_RULE,
 +    CFIR_VAL_EXPRESSION_RULE
 +  };
 +
 +  // Produce the tag that identifies the child class of this object.
 +  virtual CFIRTag getTag() const = 0;
  };
  // Rule: the value the register had in the caller cannot be recovered.
  class CallFrameInfo::UndefinedRule: public CallFrameInfo::Rule {
   public:
    UndefinedRule() { }
    ~UndefinedRule() { }
 +  CFIRTag getTag() const { return CFIR_UNDEFINED_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->UndefinedRule(address, reg);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 -    const UndefinedRule *our_rhs = dynamic_cast<const UndefinedRule *>(&rhs);
 -    return (our_rhs != NULL);
 +    if (rhs.getTag() != CFIR_UNDEFINED_RULE) return false;
 +    return true;
    }
    Rule *Copy() const { return new UndefinedRule(*this); }
  };
  // Rule: the register's value is the same as that it had in the caller.
  class CallFrameInfo::SameValueRule: public CallFrameInfo::Rule {
   public:
    SameValueRule() { }
    ~SameValueRule() { }
 +  CFIRTag getTag() const { return CFIR_SAME_VALUE_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->SameValueRule(address, reg);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 -    const SameValueRule *our_rhs = dynamic_cast<const SameValueRule *>(&rhs);
 -    return (our_rhs != NULL);
 +    if (rhs.getTag() != CFIR_SAME_VALUE_RULE) return false;
 +    return true;
    }
    Rule *Copy() const { return new SameValueRule(*this); }
  };
  // Rule: the register is saved at OFFSET from BASE_REGISTER.  BASE_REGISTER
  // may be CallFrameInfo::Handler::kCFARegister.
  class CallFrameInfo::OffsetRule: public CallFrameInfo::Rule {
   public:
    OffsetRule(int base_register, long offset)
        : base_register_(base_register), offset_(offset) { }
    ~OffsetRule() { }
 +  CFIRTag getTag() const { return CFIR_OFFSET_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->OffsetRule(address, reg, base_register_, offset_);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 -    const OffsetRule *our_rhs = dynamic_cast<const OffsetRule *>(&rhs);
 -    return (our_rhs &&
 -            base_register_ == our_rhs->base_register_ &&
 +    if (rhs.getTag() != CFIR_OFFSET_RULE) return false;
 +    const OffsetRule *our_rhs = static_cast<const OffsetRule *>(&rhs);
 +    return (base_register_ == our_rhs->base_register_ &&
              offset_ == our_rhs->offset_);
    }
    Rule *Copy() const { return new OffsetRule(*this); }
    // We don't actually need SetBaseRegister or SetOffset here, since they
    // are only ever applied to CFA rules, for DW_CFA_def_cfa_offset, and it
    // doesn't make sense to use OffsetRule for computing the CFA: it
    // computes the address at which a register is saved, not a value.
   private:
@@ -959,90 +971,89 @@
  // Rule: the value the register had in the caller is the value of
  // BASE_REGISTER plus offset. BASE_REGISTER may be
  // CallFrameInfo::Handler::kCFARegister.
  class CallFrameInfo::ValOffsetRule: public CallFrameInfo::Rule {
   public:
    ValOffsetRule(int base_register, long offset)
        : base_register_(base_register), offset_(offset) { }
    ~ValOffsetRule() { }
 +  CFIRTag getTag() const { return CFIR_VAL_OFFSET_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->ValOffsetRule(address, reg, base_register_, offset_);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 -    const ValOffsetRule *our_rhs = dynamic_cast<const ValOffsetRule *>(&rhs);
 -    return (our_rhs &&
 -            base_register_ == our_rhs->base_register_ &&
 +    if (rhs.getTag() != CFIR_VAL_OFFSET_RULE) return false;
 +    const ValOffsetRule *our_rhs = static_cast<const ValOffsetRule *>(&rhs);
 +    return (base_register_ == our_rhs->base_register_ &&
              offset_ == our_rhs->offset_);
    }
    Rule *Copy() const { return new ValOffsetRule(*this); }
    void SetBaseRegister(unsigned reg) { base_register_ = reg; }
    void SetOffset(long long offset) { offset_ = offset; }
   private:
    int base_register_;
    long offset_;
  };
  // Rule: the register has been saved in another register REGISTER_NUMBER_.
  class CallFrameInfo::RegisterRule: public CallFrameInfo::Rule {
   public:
    explicit RegisterRule(int register_number)
        : register_number_(register_number) { }
    ~RegisterRule() { }
 +  CFIRTag getTag() const { return CFIR_REGISTER_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->RegisterRule(address, reg, register_number_);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 -    const RegisterRule *our_rhs = dynamic_cast<const RegisterRule *>(&rhs);
 -    return (our_rhs && register_number_ == our_rhs->register_number_);
 +    if (rhs.getTag() != CFIR_REGISTER_RULE) return false;
 +    const RegisterRule *our_rhs = static_cast<const RegisterRule *>(&rhs);
 +    return (register_number_ == our_rhs->register_number_);
    }
    Rule *Copy() const { return new RegisterRule(*this); }
   private:
    int register_number_;
  };
  // Rule: EXPRESSION evaluates to the address at which the register is saved.
  class CallFrameInfo::ExpressionRule: public CallFrameInfo::Rule {
   public:
    explicit ExpressionRule(const string &expression)
        : expression_(expression) { }
    ~ExpressionRule() { }
 +  CFIRTag getTag() const { return CFIR_EXPRESSION_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->ExpressionRule(address, reg, expression_);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 -    const ExpressionRule *our_rhs = dynamic_cast<const ExpressionRule *>(&rhs);
 -    return (our_rhs && expression_ == our_rhs->expression_);
 +    if (rhs.getTag() != CFIR_EXPRESSION_RULE) return false;
 +    const ExpressionRule *our_rhs = static_cast<const ExpressionRule *>(&rhs);
 +    return (expression_ == our_rhs->expression_);
    }
    Rule *Copy() const { return new ExpressionRule(*this); }
   private:
    string expression_;
  };
  // Rule: EXPRESSION evaluates to the address at which the register is saved.
  class CallFrameInfo::ValExpressionRule: public CallFrameInfo::Rule {
   public:
    explicit ValExpressionRule(const string &expression)
        : expression_(expression) { }
    ~ValExpressionRule() { }
 +  CFIRTag getTag() const { return CFIR_VAL_EXPRESSION_RULE; }
    bool Handle(Handler *handler, uint64 address, int reg) const {
      return handler->ValExpressionRule(address, reg, expression_);
    }
    bool operator==(const Rule &rhs) const {
 -    // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 -    // been carefully considered; cheap RTTI-like workarounds are forbidden.
 +    if (rhs.getTag() != CFIR_VAL_EXPRESSION_RULE) return false;
      const ValExpressionRule *our_rhs =
 -        dynamic_cast<const ValExpressionRule *>(&rhs);
 -    return (our_rhs && expression_ == our_rhs->expression_);
 +        static_cast<const ValExpressionRule *>(&rhs);
 +    return (expression_ == our_rhs->expression_);
    }
    Rule *Copy() const { return new ValExpressionRule(*this); }
   private:
    string expression_;
  };
  // A map from register numbers to rules.
  class CallFrameInfo::RuleMap {

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toolkit/crashreporter/breakpad-patches/08-dwarf2reader-dynamic-cast.patch@129ffea94266 (annotated)

toolkit/crashreporter/breakpad-patches/08-dwarf2reader-dynamic-cast.patch