sal/osl/w32/backtrace.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <sal/config.h>
  11
  12 #include <limits>
  13 #include <memory>
  14
  15 #if !defined WIN32_LEAN_AND_MEAN
  16 # define WIN32_LEAN_AND_MEAN
  17 #endif
  18 #include <windows.h>
  19 #include <process.h>
  20 #include <iostream>
  21 #define OPTIONAL
  22 #include <DbgHelp.h>
  23
  24 #include <rtl/ustrbuf.hxx>
  25 #include <sal/backtrace.hxx>
  26
  27 #include <backtraceasstring.hxx>
  28
  29 namespace {
  30
  31 template<typename T> T clampToULONG(T n) {
  32     auto const maxUlong = std::numeric_limits<ULONG>::max();
  33     return n > maxUlong ? static_cast<T>(maxUlong) : n;
  34 }
  35
  36 }
  37
  38 OUString osl::detail::backtraceAsString(sal_uInt32 maxDepth)
  39 {
  40     std::unique_ptr<sal::BacktraceState> backtrace = sal::backtrace_get( maxDepth );
  41     return sal::backtrace_to_string( backtrace.get());
  42 }
  43
  44 std::unique_ptr<sal::BacktraceState> sal::backtrace_get(sal_uInt32 maxDepth)
  45 {
  46     assert(maxDepth != 0);
  47     maxDepth = clampToULONG(maxDepth);
  48
  49     auto pStack = new void *[maxDepth];
  50     // https://msdn.microsoft.com/en-us/library/windows/desktop/bb204633.aspx
  51     // "CaptureStackBackTrace function" claims that you "can capture up to
  52     // MAXUSHORT frames", and on Windows Server 2003 and Windows XP it even
  53     // "must be less than 63", but assume that a too large input value is
  54     // clamped internally, instead of resulting in an error:
  55     int nFrames = CaptureStackBackTrace( 0, static_cast<ULONG>(maxDepth), pStack, nullptr );
  56
  57     return std::unique_ptr<BacktraceState>(new BacktraceState{ pStack, nFrames });
  58 }
  59
  60 OUString sal::backtrace_to_string(BacktraceState* backtraceState)
  61 {
  62     HANDLE hProcess = GetCurrentProcess();
  63     // https://docs.microsoft.com/en-us/windows/win32/api/dbghelp/nf-dbghelp-syminitialize
  64     // says to not initialize more than once.
  65     [[maybe_unused]] static bool bInitialized = SymInitialize(hProcess, nullptr, false);
  66     SymRefreshModuleList(hProcess);
  67     SYMBOL_INFO  * pSymbol;
  68     pSymbol = static_cast<SYMBOL_INFO *>(calloc( sizeof( SYMBOL_INFO ) + 1024 * sizeof( char ), 1 ));
  69     assert(pSymbol);
  70     pSymbol->MaxNameLen = 1024 - 1;
  71     pSymbol->SizeOfStruct = sizeof( SYMBOL_INFO );
  72
  73     auto nFrames = backtraceState->nDepth;
  74     OUStringBuffer aBuf;
  75     for( int i = 0; i < nFrames; i++ )
  76     {
  77         auto pSymAddr = reinterpret_cast<DWORD64>(backtraceState->buffer[ i ]);
  78         SymFromAddr( hProcess, pSymAddr, nullptr, pSymbol );
  79         aBuf.append( OUString::number(nFrames - i - 1) + ": " );
  80         aBuf.appendAscii( pSymbol->Name );
  81         aBuf.append( " - 0x" + OUString::number(pSymAddr, 16) + "\n" );
  82     }
  83
  84     free( pSymbol );
  85
  86     return aBuf.makeStringAndClear();
  87 }
  88
  89
  90 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */