Add some debugging infrastructure to the interpreter.

This currently mainly intended to be useful in a C++ debugger. The
infrastructure makes it a lot easier to access (parent) contexts, find
function names, etc.

Change-Id: I0493d3a3bd4bf5c3a03379c1a2b545ed76862cd5
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 183 insertions, 0 deletions

diff --git a/debugging.cpp b/debugging.cpp
new file mode 100644
index 0000000000..741d5daee4
--- /dev/null
+++ b/debugging.cpp
@@ -0,0 +1,183 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include "debugging.h"
+#include "qmljs_objects.h"
+
+#include <iostream>
+
+using namespace QQmlJS;
+using namespace QQmlJS::Debugging;
+
+FunctionState::FunctionState(VM::ExecutionContext *context)
+    : _context(context)
+{
+    if (debugger())
+        debugger()->enterFunction(this);
+}
+
+FunctionState::~FunctionState()
+{
+    if (debugger())
+        debugger()->leaveFunction(this);
+}
+
+VM::Value *FunctionState::argument(unsigned idx)
+{
+    if (idx < _context->variableEnvironment->argumentCount)
+        return _context->variableEnvironment->arguments + idx;
+    else
+        return 0;
+}
+
+VM::Value *FunctionState::local(unsigned idx)
+{
+    if (idx < _context->variableEnvironment->varCount)
+        return _context->variableEnvironment->locals + idx;
+    else
+        return 0;
+}
+
+Debugger::Debugger(VM::ExecutionEngine *engine)
+    : _engine(engine)
+{
+}
+
+Debugger::~Debugger()
+{
+    qDeleteAll(_functionInfo.values());
+}
+
+void Debugger::addFunction(IR::Function *function)
+{
+    _functionInfo.insert(function, new FunctionDebugInfo(function));
+}
+
+void Debugger::addaddBasicBlockOffset(IR::Function *function, IR::BasicBlock *block, ptrdiff_t blockOffset)
+{
+    _functionInfo[function]->addBasicBlockOffset(block, blockOffset);
+}
+
+void Debugger::setSourceLocation(IR::Function *function, unsigned line, unsigned column)
+{
+    _functionInfo[function]->setSourceLocation(line, column);
+}
+
+FunctionDebugInfo *Debugger::debugInfo(VM::FunctionObject *function) const
+{
+    if (!function)
+        return 0;
+
+    if (VM::ScriptFunction *sf = function->asScriptFunction())
+        return _functionInfo[sf->function];
+    else
+        return 0;
+}
+
+QString Debugger::name(VM::FunctionObject *function) const
+{
+    if (FunctionDebugInfo *i = debugInfo(function))
+        if (i->function)
+            if (const QString *n = i->function->name)
+                return *n;
+
+    return QString();
+}
+
+void Debugger::aboutToCall(VM::FunctionObject *function, VM::ExecutionContext *context)
+{
+    _callStack.append(CallInfo(context, function));
+}
+
+void Debugger::justLeft(VM::ExecutionContext *context)
+{
+    int idx = callIndex(context);
+    if (idx < 0)
+        qDebug() << "Oops, leaving a function that was not registered...?";
+    else
+        _callStack.resize(idx);
+}
+
+void Debugger::enterFunction(FunctionState *state)
+{
+    _callStack[callIndex(state->context())].state = state;
+
+#ifdef DO_TRACE_INSTR
+    QString n = name(_callStack[callIndex(state->context())].function);
+    std::cerr << "*** Entering \"" << qPrintable(n) << "\" with" << state->context()->variableEnvironment->argumentCount << "args" << std::endl;
+    for (unsigned i = 0; i < state->context()->variableEnvironment->argumentCount; ++i)
+        std::cerr << "        " << i << ": " << currentArg(i) << std::endl;
+#endif // DO_TRACE_INSTR
+}
+
+void Debugger::leaveFunction(FunctionState *state)
+{
+    _callStack[callIndex(state->context())].state = 0;
+}
+
+void Debugger::aboutToThrow(VM::Value *value)
+{
+    qDebug() << "*** We are about to throw...:" << value->toString(currentState()->context())->toQString();
+}
+
+FunctionState *Debugger::currentState() const
+{
+    if (_callStack.isEmpty())
+        return 0;
+    else
+        return _callStack.last().state;
+}
+
+const char *Debugger::currentArg(unsigned idx) const
+{
+    FunctionState *state = currentState();
+    return qPrintable(state->argument(idx)->toString(state->context())->toQString());
+}
+
+const char *Debugger::currentLocal(unsigned idx) const
+{
+    FunctionState *state = currentState();
+    return qPrintable(state->local(idx)->toString(state->context())->toQString());
+}
+
+const char *Debugger::currentTemp(unsigned idx) const
+{
+    FunctionState *state = currentState();
+    return qPrintable(state->temp(idx)->toString(state->context())->toQString());
+}
+
+int Debugger::callIndex(VM::ExecutionContext *context)
+{
+    for (int idx = _callStack.size() - 1; idx >= 0; --idx) {
+        if (_callStack[idx].context == context)
+            return idx;
+    }
+
+    return -1;
+}