refs #540 Add the ability to capture the current call stack, and use it in singleShot.

src/blackmisc/blackmisc.pro

@@ -57,7 +57,7 @@ SOURCES +=  *.cpp \
             $$PWD/weather/*.cpp
 
 win32 {
-    LIBS *= -lShell32
+    LIBS *= -lShell32 -lDbghelp
 }
 
 DESTDIR = $$DestRoot/lib

src/blackmisc/stacktrace.cpp

@@ -0,0 +1,95 @@
+/* Copyright (C) 2015
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "blackmisc/stacktrace.h"
+#include <QMutex>
+#include <array>
+#if defined(Q_OS_WIN32)
+#   include <windows.h>
+#   pragma warning(push)
+#   pragma warning(disable:4091)
+#   include <dbghelp.h>
+#   pragma warning(pop)
+#elif defined(Q_CC_GNU)
+#   include <execinfo.h>
+#endif
+
+namespace BlackMisc
+{
+
+#if defined(QT_NO_DEBUG)
+    QStringList getStackTrace()
+    {
+        return { "No stack trace with release build" };
+    }
+#elif defined(Q_OS_WIN32)
+    QStringList getStackTrace()
+    {
+        static QMutex mutex;
+        QMutexLocker lock(&mutex);
+
+        auto process = GetCurrentProcess();
+        SymInitialize(process, nullptr, true);
+
+        std::array<void*, 100> stack;
+        auto frames = CaptureStackBackTrace(1, static_cast<DWORD>(stack.size()), stack.data(), nullptr);
+
+        struct
+        {
+            SYMBOL_INFO info;
+            std::array<char, 256> name;
+        } symbol;
+        symbol.info.MaxNameLen = static_cast<ULONG>(symbol.name.size() - 1);
+        symbol.info.SizeOfStruct = sizeof(symbol.info);
+
+        QStringList result;
+        for (int i = 0; i < frames; ++i)
+        {
+            DWORD displacement = 0;
+            IMAGEHLP_LINE64 line;
+            line.SizeOfStruct = sizeof(line);
+            SymFromAddr(process, reinterpret_cast<quintptr>(stack[i]), nullptr, &symbol.info);
+            SymGetLineFromAddr64(process, reinterpret_cast<quintptr>(stack[i]), &displacement, &line);
+
+            result.push_back(QString(symbol.info.Name) + " line " + QString::number(line.LineNumber));
+        }
+        return result;
+    }
+#elif defined(Q_CC_GNU)
+    QStringList getStackTrace()
+    {
+        std::array<void*, 100> stack;
+        auto frames = backtrace(stack.data(), stack.size());
+        auto *symbols = backtrace_symbols(stack.data(), frames);
+
+        QStringList result;
+        QString symbol;
+        char *demangled = nullptr;
+        size_t size = 0;
+        for (int i = 0; i < frames; ++i)
+        {
+            symbol = symbols[i];
+            int end = symbol.indexOf(' ');
+            if (end > 0) { symbol.truncate(end); }
+
+            demangled = abi::__cxa_demangle(qPrintable(symbol), demangled, &size, nullptr);
+            result.push_back(demangled);
+        }
+        free(symbols);
+        free(demangled);
+        return result;
+    }
+#else
+    QStringList getStackTrace()
+    {
+        return { "No stack trace on this platform" };
+    }
+#endif
+
+}

src/blackmisc/stacktrace.h

@@ -0,0 +1,26 @@
+/* Copyright (C) 2015
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+//! \file
+
+#ifndef BLACKMISC_STACKTRACE_H
+#define BLACKMISC_STACKTRACE_H
+
+#include "blackmisc/blackmiscexport.h"
+#include <QStringList>
+
+namespace BlackMisc
+{
+    /*!
+     * Returns a stack trace of the current thread of execution as a list of function names.
+     */
+    BLACKMISC_EXPORT QStringList getStackTrace();
+}
+
+#endif

src/blackmisc/worker.h

@@ -14,6 +14,7 @@
 
 #include "blackmiscexport.h"
 #include "variant.h"
+#include "stacktrace.h"
 #include <QThread>
 #include <QMutex>
 #include <QTimer>
@@ -53,8 +54,10 @@ namespace BlackMisc
         auto *timer = new QTimer;
         timer->setSingleShot(true);
         timer->moveToThread(target);
+        auto trace = getStackTrace();
         QObject::connect(timer, &QTimer::timeout, [ = ]()
         {
+            static_cast<void>(trace);
             task();
             timer->deleteLater();
         });