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