PDBReader.cpp

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#include "PDBReader.h"
 
#include <fstream>
 
#include <Logger/Logger.h>
#include <Tools.h>
 
#include "../Private/Helpers.h"
#include "../Private/Offsets.h"
 
namespace API
{
    template <typename T>
    class ScopedDiaType
    {
    public:
        ScopedDiaType() : _sym(nullptr)
        {
        }
 
        ScopedDiaType(T* sym) : _sym(sym)
        {
        }
 
        ~ScopedDiaType()
        {
            if (_sym != nullptr)
                _sym->Release();
        }
 
        T** ref() { return &_sym; }
        T** operator&() { return ref(); }
        T* operator->() { return _sym; }
        operator T*() { return _sym; }
        void Attach(T* sym) { _sym = sym; }
 
    private:
        T* _sym;
    };
 
    template <typename T>
    using CComPtr = ScopedDiaType<T>;
 
    void PdbReader::Read(const std::wstring& path, std::unordered_map<std::string, intptr_t>* offsets_dump,
                         std::unordered_map<std::string, BitField>* bitfields_dump)
    {
        offsets_dump_ = offsets_dump;
        bitfields_dump_ = bitfields_dump;
 
        std::ifstream f{path};
        if (!f.good())
            throw std::runtime_error("Failed to open pdb file");
 
        IDiaDataSource* data_source;
        IDiaSession* dia_session;
        IDiaSymbol* symbol;
 
        try
        {
            LoadDataFromPdb(path, &data_source, &dia_session, &symbol);
        }
        catch (const std::runtime_error&)
        {
            Log::GetLog()->error("Failed to load data from pdb file ");
            throw;
        }
 
        Log::GetLog()->info("Dumping structures..");
        DumpStructs(symbol);
 
        Log::GetLog()->info("Dumping functions..");
        DumpFunctions(symbol);
 
        Log::GetLog()->info("Dumping globals..");
        DumpGlobalVariables(symbol);
 
        Cleanup(symbol, dia_session, data_source);
 
        Log::GetLog()->info("Successfully read information from PDB\n");
    }
 
    void PdbReader::LoadDataFromPdb(const std::wstring& path, IDiaDataSource** dia_source, IDiaSession** session,
                                    IDiaSymbol** symbol)
    {
        const std::string current_dir = Tools::GetCurrentDir();
 
        const std::string lib_path = current_dir + "\\msdia140.dll";
        const HMODULE h_module = LoadLibraryA(lib_path.c_str());
        if (h_module == nullptr)
        {
            throw std::runtime_error("Failed to load msdia140.dll. Error code - " + std::to_string(GetLastError()));
        }
 
        const auto dll_get_class_object = reinterpret_cast<HRESULT(WINAPI*)(REFCLSID, REFIID, LPVOID)>(GetProcAddress(
            h_module, "DllGetClassObject"));
        if (dll_get_class_object == nullptr)
        {
            throw std::runtime_error("Can't find DllGetClassObject. Error code - " + std::to_string(GetLastError()));
        }
 
        IClassFactory* class_factory;
        HRESULT hr = dll_get_class_object(__uuidof(DiaSource), IID_IClassFactory, &class_factory);
        if (FAILED(hr))
        {
            throw std::runtime_error("DllGetClassObject has failed. Error code - " + std::to_string(GetLastError()));
        }
 
        hr = class_factory->CreateInstance(nullptr, __uuidof(IDiaDataSource), reinterpret_cast<void**>(dia_source));
        if (FAILED(hr))
        {
            class_factory->Release();
            throw std::runtime_error("CreateInstance has failed. Error code - " + std::to_string(GetLastError()));
        }
 
        hr = (*dia_source)->loadDataFromPdb(path.c_str());
        if (FAILED(hr))
        {
            class_factory->Release();
            throw std::runtime_error("loadDataFromPdb has failed. HRESULT - " + std::to_string(hr));
        }
 
        // Open a session for querying symbols
 
        hr = (*dia_source)->openSession(session);
        if (FAILED(hr))
        {
            class_factory->Release();
            throw std::runtime_error("openSession has failed. HRESULT - " + std::to_string(hr));
        }
 
        // Retrieve a reference to the global scope
 
        hr = (*session)->get_globalScope(symbol);
        if (hr != S_OK)
        {
            class_factory->Release();
            throw std::runtime_error("get_globalScope has failed. HRESULT - " + std::to_string(hr));
        }
 
        class_factory->Release();
    }
 
    void PdbReader::DumpStructs(IDiaSymbol* g_symbol)
    {
        IDiaSymbol* symbol = nullptr;
 
        CComPtr<IDiaEnumSymbols> enum_symbols;
        if (FAILED(g_symbol->findChildren(SymTagUDT, nullptr, nsNone, &enum_symbols)))
            throw std::runtime_error("Failed to find symbols");
 
        ULONG celt = 0;
        while (SUCCEEDED(enum_symbols->Next(1, &symbol, &celt)) && celt == 1)
        {
            CComPtr<IDiaSymbol> sym(symbol);
 
            const uint32_t sym_id = GetSymbolId(symbol);
            if (visited_.find(sym_id) != visited_.end())
                return;
 
            visited_.insert(sym_id);
 
            std::string str_name = GetSymbolNameString(sym);
            if (str_name.empty())
                continue;
 
            DumpType(sym, str_name, 0);
        }
    }
 
    void PdbReader::DumpFunctions(IDiaSymbol* g_symbol)
    {
        IDiaSymbol* symbol;
 
        CComPtr<IDiaEnumSymbols> enum_symbols;
        if (FAILED(g_symbol->findChildren(SymTagFunction, nullptr, nsNone, &enum_symbols)))
            throw std::runtime_error("Failed to find symbols");
 
        ULONG celt = 0;
        while (SUCCEEDED(enum_symbols->Next(1, &symbol, &celt)) && celt == 1)
        {
            CComPtr<IDiaSymbol> sym(symbol);
 
            DWORD sym_tag_type;
            if (sym->get_symTag(&sym_tag_type) != S_OK)
                continue;
 
            const uint32_t sym_id = GetSymbolId(sym);
            if (visited_.find(sym_id) != visited_.end())
                continue;
 
            visited_.insert(sym_id);
 
            std::string str_name = GetSymbolNameString(sym);
            if (str_name.empty())
                continue;
 
            DWORD offset;
            if (sym->get_addressOffset(&offset) != S_OK)
                continue;
 
            // Filter out some useless functions
            if (str_name.find('`') != std::string::npos)
                continue;
 
            // Check if it's a member function
            if (str_name.find(':') != std::string::npos)
            {
                const std::string new_str = ReplaceString(str_name, "::", ".");
 
                (*offsets_dump_)[new_str] = offset;
            }
            else
            {
                (*offsets_dump_)["Global." + str_name] = offset;
            }
        }
    }
 
    void PdbReader::DumpGlobalVariables(IDiaSymbol* g_symbol)
    {
        IDiaSymbol* symbol;
 
        CComPtr<IDiaEnumSymbols> enum_symbols;
        if (FAILED(g_symbol->findChildren(SymTagData, nullptr, nsNone, &enum_symbols)))
            throw std::runtime_error("Failed to find symbols");
 
        ULONG celt = 0;
        while (SUCCEEDED(enum_symbols->Next(1, &symbol, &celt)) && celt == 1)
        {
            CComPtr<IDiaSymbol> sym(symbol);
 
            const uint32_t sym_id = GetSymbolId(symbol);
            if (visited_.find(sym_id) != visited_.end())
                return;
 
            visited_.insert(sym_id);
 
            std::string str_name = GetSymbolNameString(sym);
            if (str_name.empty())
                continue;
 
            DWORD sym_tag;
            if (sym->get_symTag(&sym_tag) != S_OK)
                continue;
 
            DWORD offset;
            if (sym->get_addressOffset(&offset) != S_OK)
                continue;
 
            (*offsets_dump_)["Global." + str_name] = offset;
        }
    }
 
    void PdbReader::DumpType(IDiaSymbol* symbol, const std::string& structure, int indent) const
    {
        CComPtr<IDiaEnumSymbols> enum_children;
        IDiaSymbol* symbol_child;
        DWORD sym_tag;
        ULONG celt = 0;
 
        if (indent > 5)
            return;
 
        if (symbol->get_symTag(&sym_tag) != S_OK)
            return;
 
        switch (sym_tag)
        {
        case SymTagData:
            DumpData(symbol, structure);
            break;
        case SymTagEnum:
        case SymTagUDT:
            if (SUCCEEDED(symbol->findChildren(SymTagNull, nullptr, nsNone, &enum_children)))
            {
                while (SUCCEEDED(enum_children->Next(1, &symbol_child, &celt)) && celt == 1)
                {
                    CComPtr<IDiaSymbol> sym_child(symbol_child);
 
                    DumpType(sym_child, structure, indent + 2);
                }
            }
            break;
        default:
            break;
        }
    }
 
    void PdbReader::DumpData(IDiaSymbol* symbol, const std::string& structure) const
    {
        DWORD loc_type;
        if (symbol->get_locationType(&loc_type) != S_OK)
            return;
 
        if (loc_type != LocIsThisRel && loc_type != LocIsBitField)
            return;
 
        CComPtr<IDiaSymbol> type;
        if (symbol->get_type(&type) != S_OK)
            return;
 
        if (type == nullptr)
            return;
 
        LONG offset;
        if (symbol->get_offset(&offset) != S_OK)
            return;
 
        std::string str_name = GetSymbolNameString(symbol);
        if (str_name.empty())
            return;
 
        if (loc_type == LocIsBitField)
        {
            DWORD bit_position;
            if (symbol->get_bitPosition(&bit_position) != S_OK)
                return;
 
            ULONGLONG num_bits;
            if (symbol->get_length(&num_bits) != S_OK)
                return;
 
            ULONGLONG length;
            if (type->get_length(&length) != S_OK)
                return;
 
            const BitField bit_field{static_cast<DWORD64>(offset), bit_position, num_bits, length};
 
            (*bitfields_dump_)[structure + "." + str_name] = bit_field;
        }
        else if (loc_type == LocIsThisRel)
        {
            (*offsets_dump_)[structure + "." + str_name] = offset;
        }
    }
 
    std::string PdbReader::GetSymbolNameString(IDiaSymbol* symbol)
    {
        BSTR str = nullptr;
 
        std::string name;
 
        HRESULT hr = symbol->get_name(&str);
        if (hr != S_OK)
            return name;
 
        if (str != nullptr)
        {
            name = Tools::Utf8Encode(str);
        }
 
        SysFreeString(str);
 
        return name;
    }
 
    uint32_t PdbReader::GetSymbolId(IDiaSymbol* symbol)
    {
        DWORD id;
        symbol->get_symIndexId(&id);
 
        return id;
    }
 
    void PdbReader::Cleanup(IDiaSymbol* symbol, IDiaSession* session, IDiaDataSource* source)
    {
        if (symbol != nullptr)
            symbol->Release();
        if (session != nullptr)
            session->Release();
        if (source != nullptr)
            source->Release();
 
        CoUninitialize();
    }
} // namespace API