    /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
    /*
     * This file is part of the LibreOffice project.
     *
     * This Source Code Form is subject to the terms of the Mozilla Public
     * License, v. 2.0. If a copy of the MPL was not distributed with this
     * file, You can obtain one at http://mozilla.org/MPL/2.0/.
     */

    #include <sal/config.h>

    #include <limits>
    #include <memory>

    #if !defined WIN32_LEAN_AND_MEAN
    # define WIN32_LEAN_AND_MEAN
    #endif
    #include <windows.h>
    #include <process.h>
    #include <iostream>
    #define OPTIONAL
    #include <DbgHelp.h>

    #include <rtl/ustrbuf.hxx>
    #include <sal/backtrace.hxx>

    #include <backtraceasstring.hxx>

    namespace {

    template<typename T> T clampToULONG(T n) {
        auto const maxUlong = std::numeric_limits<ULONG>::max();
        return n > maxUlong ? static_cast<T>(maxUlong) : n;
    }

    }

    OUString osl::detail::backtraceAsString(sal_uInt32 maxDepth)
    {
        assert(maxDepth != 0);
        maxDepth = clampToULONG(maxDepth);

        OUStringBuffer aBuf;

        HANDLE hProcess = GetCurrentProcess();
        SymInitialize( hProcess, nullptr, true );

        std::unique_ptr<void*[]> aStack(new void*[ maxDepth ]);
        // https://msdn.microsoft.com/en-us/library/windows/desktop/bb204633.aspx
        // "CaptureStackBackTrace function" claims that you "can capture up to
        // MAXUSHORT frames", and on Windows Server 2003 and Windows XP it even
        // "must be less than 63", but assume that a too large input value is
        // clamped internally, instead of resulting in an error:
        sal_uInt32 nFrames = CaptureStackBackTrace( 0, static_cast<ULONG>(maxDepth), aStack.get(), nullptr );

        SYMBOL_INFO  * pSymbol;
        pSymbol = static_cast<SYMBOL_INFO *>(calloc( sizeof( SYMBOL_INFO ) + 1024 * sizeof( char ), 1 ));
        pSymbol->MaxNameLen = 1024 - 1;
        pSymbol->SizeOfStruct = sizeof( SYMBOL_INFO );

        for( sal_uInt32 i = 0; i < nFrames; i++ )
        {
            SymFromAddr( hProcess, reinterpret_cast<DWORD64>(aStack[ i ]), nullptr, pSymbol );
            aBuf.append( static_cast<sal_Int32>(nFrames - i - 1) );
            aBuf.append( ": " );
            aBuf.appendAscii( pSymbol->Name );
            aBuf.append( " - 0x" );
            aBuf.append( static_cast<sal_Int64>(pSymbol->Address), 16 );
            aBuf.append( "\n" );
        }

        free( pSymbol );

        return aBuf.makeStringAndClear();
    }

    std::unique_ptr<sal::BacktraceState> sal::backtrace_get(sal_uInt32 maxDepth)
    {
        assert(maxDepth != 0);
        maxDepth = clampToULONG(maxDepth);

        HANDLE hProcess = GetCurrentProcess();
        SymInitialize( hProcess, nullptr, true );

        auto pStack = new void *[maxDepth];
        // https://msdn.microsoft.com/en-us/library/windows/desktop/bb204633.aspx
        // "CaptureStackBackTrace function" claims that you "can capture up to
        // MAXUSHORT frames", and on Windows Server 2003 and Windows XP it even
        // "must be less than 63", but assume that a too large input value is
        // clamped internally, instead of resulting in an error:
        int nFrames = CaptureStackBackTrace( 0, static_cast<ULONG>(maxDepth), pStack, nullptr );

        return std::unique_ptr<BacktraceState>(new BacktraceState{ pStack, nFrames });
    }

    OUString sal::backtrace_to_string(BacktraceState* backtraceState)
    {
        OUStringBuffer aBuf;

        SYMBOL_INFO  * pSymbol;
        pSymbol = static_cast<SYMBOL_INFO *>(calloc( sizeof( SYMBOL_INFO ) + 1024 * sizeof( char ), 1 ));
        pSymbol->MaxNameLen = 1024 - 1;
        pSymbol->SizeOfStruct = sizeof( SYMBOL_INFO );
        HANDLE hProcess = GetCurrentProcess();

        auto nFrames = backtraceState->nDepth;
        for( int i = 0; i < nFrames; i++ )
        {
            SymFromAddr( hProcess, reinterpret_cast<DWORD64>(backtraceState->buffer[ i ]), nullptr, pSymbol );
            aBuf.append( static_cast<sal_Int32>(nFrames - i - 1) );
            aBuf.append( ": " );
            aBuf.appendAscii( pSymbol->Name );
            aBuf.append( " - 0x" );
            aBuf.append( static_cast<sal_Int64>(pSymbol->Address), 16 );
            aBuf.append( "\n" );
        }

        free( pSymbol );

        return aBuf.makeStringAndClear();
    }

    /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

↑ V522 There might be dereferencing of a potential null pointer 'pSymbol'. Check lines: 102, 101.

↑ V522 There might be dereferencing of a potential null pointer 'pSymbol'. Check lines: 58, 57.