llvm-project/lldb/source/Plugins/SymbolFile/DWARF/HashedNameToDIE.h

//===-- HashedNameToDIE.h ---------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef SymbolFileDWARF_HashedNameToDIE_h_
#define SymbolFileDWARF_HashedNameToDIE_h_

#include <vector>

#include "lldb/lldb-defines.h"
#include "lldb/Core/dwarf.h"
#include "lldb/Core/RegularExpression.h"
#include "lldb/Core/MappedHash.h"

#include "DWARFDefines.h"
#include "DWARFFormValue.h"
#include "NameToDIE.h"

class SymbolFileDWARF;
class DWARFCompileUnit;
class DWARFDebugInfoEntry;

class DWARFMappedHash
{
public:
    enum AtomType : uint16_t
    {
        eAtomTypeNULL         = 0u,
        eAtomTypeDIEOffset    = 1u, // DIE offset, check form for encoding
        eAtomTypeCUOffset     = 2u, // DIE offset of the compiler unit header that contains the item in question
        eAtomTypeTag          = 3u, // DW_TAG_xxx value, should be encoded as DW_FORM_data1 (if no tags exceed 255) or DW_FORM_data2
        eAtomTypeNameFlags    = 4u, // Flags from enum NameFlags
        eAtomTypeTypeFlags    = 5u, // Flags from enum TypeFlags,
        eAtomTypeQualNameHash = 6u  // A 32 bit hash of the full qualified name (since all hash entries are basename only)
                                    // For example a type like "std::vector<int>::iterator" would have a name of "iterator"
                                    // and a 32 bit hash for "std::vector<int>::iterator" to allow us to not have to pull
                                    // in debug info for a type when we know the fully qualified name.
    };

    // Bit definitions for the eAtomTypeTypeFlags flags
    enum TypeFlags
    {
        // Always set for C++, only set for ObjC if this is the 
        // @implementation for class
        eTypeFlagClassIsImplementation  = ( 1u << 1 )
    };

    struct DIEInfo
    {
        dw_offset_t cu_offset;
        dw_offset_t offset;  // The DIE offset
        dw_tag_t tag;
        uint32_t type_flags; // Any flags for this DIEInfo
        uint32_t qualified_name_hash; // A 32 bit hash of the fully qualified name

        DIEInfo ();
        DIEInfo (dw_offset_t c, dw_offset_t o, dw_tag_t t, uint32_t f, uint32_t h);
    };

    struct Atom
    {
        AtomType type;
        dw_form_t form;
    };

    typedef std::vector<DIEInfo> DIEInfoArray;
    typedef std::vector<Atom> AtomArray;

    class Prologue
    {
    public:
        Prologue (dw_offset_t _die_base_offset = 0);

        void
        ClearAtoms ();

        bool
        ContainsAtom (AtomType atom_type) const;

        void
        Clear ();

        void
        AppendAtom (AtomType type, dw_form_t form);

        lldb::offset_t
        Read (const lldb_private::DataExtractor &data, lldb::offset_t offset);

        size_t
        GetByteSize () const;

        size_t
        GetMinimumHashDataByteSize () const;

        bool
        HashDataHasFixedByteSize() const;

        // DIE offset base so die offsets in hash_data can be CU relative
        dw_offset_t die_base_offset;
        AtomArray atoms;
        uint32_t atom_mask;
        size_t min_hash_data_byte_size;
        bool hash_data_has_fixed_byte_size;
    };
    
    class Header : public MappedHash::Header<Prologue>
    {
    public:
        size_t
        GetByteSize (const HeaderData &header_data) override;

        lldb::offset_t
        Read (lldb_private::DataExtractor &data, lldb::offset_t offset) override;

        bool
        Read (const lldb_private::DWARFDataExtractor &data, 
              lldb::offset_t *offset_ptr, 
              DIEInfo &hash_data) const;

        void
        Dump (lldb_private::Stream& strm, const DIEInfo &hash_data) const;
    };

    // A class for reading and using a saved hash table from a block of data
    // in memory
    class MemoryTable : public MappedHash::MemoryTable<uint32_t, DWARFMappedHash::Header, DIEInfoArray>
    {
    public:
        MemoryTable (lldb_private::DWARFDataExtractor &table_data, 
                     const lldb_private::DWARFDataExtractor &string_table,
                     const char *name);

        const char *
        GetStringForKeyType (KeyType key) const override;
        
        bool
        ReadHashData (uint32_t hash_data_offset, HashData &hash_data) const override;

        size_t
        AppendAllDIEsThatMatchingRegex (const lldb_private::RegularExpression& regex, 
                                        DIEInfoArray &die_info_array) const;

        size_t
        AppendAllDIEsInRange (const uint32_t die_offset_start, 
                              const uint32_t die_offset_end, 
                              DIEInfoArray &die_info_array) const;

        size_t
        FindByName (const char *name, DIEArray &die_offsets);

        size_t
        FindByNameAndTag (const char *name, const dw_tag_t tag, DIEArray &die_offsets);

        size_t
        FindByNameAndTagAndQualifiedNameHash (const char *name,
                                              const dw_tag_t tag,
                                              const uint32_t qualified_name_hash,
                                              DIEArray &die_offsets);

        size_t
        FindCompleteObjCClassByName (const char *name,
                                     DIEArray &die_offsets,
                                     bool must_be_implementation);

    protected:
        Result
        AppendHashDataForRegularExpression (const lldb_private::RegularExpression& regex,
                                            lldb::offset_t* hash_data_offset_ptr, 
                                            Pair &pair) const;

        size_t 
        FindByName (const char *name, DIEInfoArray &die_info_array);

        Result
        GetHashDataForName (const char *name,
                            lldb::offset_t* hash_data_offset_ptr,
                            Pair &pair) const override;

        const lldb_private::DWARFDataExtractor &m_data;
        const lldb_private::DWARFDataExtractor &m_string_table;
        std::string m_name;
    };

    static void
    ExtractDIEArray (const DIEInfoArray &die_info_array, DIEArray &die_offsets);

protected:
    static void
    ExtractDIEArray (const DIEInfoArray &die_info_array,
                     const dw_tag_t tag,
                     DIEArray &die_offsets);

    static void
    ExtractDIEArray (const DIEInfoArray &die_info_array,
                     const dw_tag_t tag,
                     const uint32_t qualified_name_hash,
                     DIEArray &die_offsets);

    static void
    ExtractClassOrStructDIEArray (const DIEInfoArray &die_info_array,
                                  bool return_implementation_only_if_available,
                                  DIEArray &die_offsets);

    static void
    ExtractTypesFromDIEArray (const DIEInfoArray &die_info_array,
                              uint32_t type_flag_mask,
                              uint32_t type_flag_value,
                              DIEArray &die_offsets);

    static const char *
    GetAtomTypeName (uint16_t atom);
};

#endif  // SymbolFileDWARF_HashedNameToDIE_h_