zeek/tools/binpac/src/pac_record.h

// See the file "COPYING" in the main distribution directory for copyright.

#ifndef pac_record_h
#define pac_record_h

#include "pac_common.h"
#include "pac_field.h"
#include "pac_id.h"
#include "pac_type.h"

class RecordType : public Type {
public:
    RecordType(RecordFieldList* fields);
    ~RecordType() override;

    bool DefineValueVar() const override;
    string DataTypeStr() const override;

    void Prepare(Env* env, int flags) override;

    void GenPubDecls(Output* out, Env* env) override;
    void GenPrivDecls(Output* out, Env* env) override;

    void GenInitCode(Output* out, Env* env) override;
    void GenCleanUpCode(Output* out, Env* env) override;

    int StaticSize(Env* env) const override;

    void SetBoundaryChecked() override;

    const ID* parsing_dataptr_var() const;

    bool IsPointerType() const override {
        ASSERT(0);
        return false;
    }

protected:
    void DoGenParseCode(Output* out, Env* env, const DataPtr& data, int flags) override;
    void GenDynamicSize(Output* out, Env* env, const DataPtr& data) override;

    Type* DoClone() const override { return nullptr; }

    void DoMarkIncrementalInput() override;

    bool DoTraverse(DataDepVisitor* visitor) override;
    bool ByteOrderSensitive() const override;

private:
    Field* parsing_dataptr_var_field_;
    RecordFieldList* record_fields_;
};

// A data field of a record type. A RecordField corresponds to a
// segment of input data, and therefore RecordField's are ordered---each
// of them has a known previous and next field.

class RecordField : public Field {
public:
    RecordField(FieldType tof, ID* id, Type* type);
    ~RecordField() override;

    RecordType* record_type() const { return record_type_; }
    void set_record_type(RecordType* ty) { record_type_ = ty; }

    virtual void GenParseCode(Output* out, Env* env) = 0;

    RecordField* prev() const { return prev_; }
    RecordField* next() const { return next_; }
    void set_prev(RecordField* f) { prev_ = f; }
    void set_next(RecordField* f) { next_ = f; }

    int static_offset() const { return static_offset_; }
    void set_static_offset(int offset) { static_offset_ = offset; }

    int parsing_state_seq() const { return parsing_state_seq_; }
    void set_parsing_state_seq(int x) { parsing_state_seq_ = x; }

    virtual int StaticSize(Env* env, int offset) const = 0;
    const char* FieldSize(Output* out, Env* env);
    const char* FieldOffset(Output* out, Env* env);

    virtual bool BoundaryChecked() const { return boundary_checked_; }
    virtual void SetBoundaryChecked() { boundary_checked_ = true; }

    virtual bool RequiresByteOrder() const = 0;

    friend class RecordType;

protected:
    RecordType* record_type_;
    RecordField* prev_;
    RecordField* next_;
    bool boundary_checked_;
    int static_offset_;
    int parsing_state_seq_;

    DataPtr* begin_of_field_dataptr;
    DataPtr* end_of_field_dataptr;
    char* field_size_expr;
    char* field_offset_expr;
    ID* end_of_field_dataptr_var;

    const DataPtr& getFieldBegin(Output* out_cc, Env* env);
    const DataPtr& getFieldEnd(Output* out_cc, Env* env);
    virtual void GenFieldEnd(Output* out, Env* env, const DataPtr& begin) = 0;

    bool AttemptBoundaryCheck(Output* out_cc, Env* env);
    virtual bool GenBoundaryCheck(Output* out_cc, Env* env) = 0;
};

class RecordDataField : public RecordField, public Evaluatable {
public:
    RecordDataField(ID* arg_id, Type* arg_type);
    ~RecordDataField() override;

    // Instantiates abstract class Field
    void Prepare(Env* env) override;
    void GenParseCode(Output* out, Env* env) override;

    // Instantiates abstract class Evaluatable
    void GenEval(Output* out, Env* env) override;

    int StaticSize(Env* env, int) const override { return type()->StaticSize(env); }

    void SetBoundaryChecked() override;

    bool RequiresByteOrder() const override { return type()->RequiresByteOrder(); }
    bool RequiresAnalyzerContext() const override;

protected:
    void GenFieldEnd(Output* out, Env* env, const DataPtr& begin) override;
    bool GenBoundaryCheck(Output* out_cc, Env* env) override;
    bool DoTraverse(DataDepVisitor* visitor) override;
};

enum PaddingType : uint8_t { PAD_BY_LENGTH, PAD_TO_OFFSET, PAD_TO_NEXT_WORD };

class RecordPaddingField : public RecordField {
public:
    RecordPaddingField(ID* id, PaddingType ptype, Expr* expr);
    ~RecordPaddingField() override;

    void Prepare(Env* env) override;

    void GenPubDecls(Output* out, Env* env) override { /* nothing */ }
    void GenPrivDecls(Output* out, Env* env) override { /* nothing */ }

    void GenInitCode(Output* out, Env* env) override { /* nothing */ }
    void GenCleanUpCode(Output* out, Env* env) override { /* nothing */ }
    void GenParseCode(Output* out, Env* env) override;

    int StaticSize(Env* env, int offset) const override;

    bool RequiresByteOrder() const override { return false; }

protected:
    void GenFieldEnd(Output* out, Env* env, const DataPtr& begin) override;
    bool GenBoundaryCheck(Output* out_cc, Env* env) override;
    bool DoTraverse(DataDepVisitor* visitor) override;

private:
    PaddingType ptype_;
    Expr* expr_;
    int wordsize_;
};

#endif // pac_record_h