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, 137 insertions, 0 deletions

diff --git a/debugging.h b/debugging.h
new file mode 100644
index 0000000000..7a0a27dfdb
--- /dev/null
+++ b/debugging.h
@@ -0,0 +1,137 @@
+/****************************************************************************
+**
+** 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.
+**
+****************************************************************************/
+
+#ifndef DEBUGGING_H
+#define DEBUGGING_H
+
+#include "qmljs_engine.h"
+#include "qmljs_environment.h"
+
+#include <QHash>
+
+namespace QQmlJS {
+
+namespace IR {
+struct BasicBlock;
+struct Function;
+} // namespace IR
+
+namespace Debugging {
+
+class Debugger;
+
+struct FunctionDebugInfo { // TODO: use opaque d-pointers here
+    IR::Function *function;
+    QHash<ptrdiff_t, IR::BasicBlock *> blockOffsets;
+    unsigned startLine, startColumn;
+
+    FunctionDebugInfo(IR::Function *function): function(function), startLine(0), startColumn(0) {}
+
+    void addBasicBlockOffset(IR::BasicBlock *block, ptrdiff_t offset) {
+        blockOffsets.insert(offset, block);
+    }
+
+    void setSourceLocation(unsigned line, unsigned column)
+    { startLine = line; startColumn = column; }
+};
+
+class FunctionState
+{
+public:
+    FunctionState(VM::ExecutionContext *context);
+    virtual ~FunctionState();
+
+    virtual VM::Value *argument(unsigned idx);
+    virtual VM::Value *local(unsigned idx);
+    virtual VM::Value *temp(unsigned idx) = 0;
+
+    VM::ExecutionContext *context() const
+    { return _context; }
+
+    Debugger *debugger() const
+    { return _context->engine->debugger; }
+
+private:
+    VM::ExecutionContext *_context;
+};
+
+struct CallInfo
+{
+    VM::ExecutionContext *context;
+    VM::FunctionObject *function;
+    FunctionState *state;
+
+    CallInfo(VM::ExecutionContext *context = 0, VM::FunctionObject *function = 0, FunctionState *state = 0)
+        : context(context)
+        , function(function)
+        , state(state)
+    {}
+};
+
+class Debugger
+{
+public:
+    Debugger(VM::ExecutionEngine *_engine);
+    ~Debugger();
+
+public: // compile-time interface
+    void addFunction(IR::Function *function);
+    void addaddBasicBlockOffset(IR::Function *function, IR::BasicBlock *block, ptrdiff_t blockOffset);
+    void setSourceLocation(IR::Function *function, unsigned line, unsigned column);
+
+public: // run-time querying interface
+    FunctionDebugInfo *debugInfo(VM::FunctionObject *function) const;
+    QString name(VM::FunctionObject *function) const;
+
+public: // execution hooks
+    void aboutToCall(VM::FunctionObject *function, VM::ExecutionContext *context);
+    void justLeft(VM::ExecutionContext *context);
+    void enterFunction(FunctionState *state);
+    void leaveFunction(FunctionState *state);
+    void aboutToThrow(VM::Value *value);
+
+public: // debugging hooks
+    FunctionState *currentState() const;
+    const char *currentArg(unsigned idx) const;
+    const char *currentLocal(unsigned idx) const;
+    const char *currentTemp(unsigned idx) const;
+
+private:
+    int callIndex(VM::ExecutionContext *context);
+
+private: // TODO: use opaque d-pointers here
+    VM::ExecutionEngine *_engine;
+    QHash<IR::Function *, FunctionDebugInfo *> _functionInfo;
+    QVector<CallInfo> _callStack;
+};
+
+} // namespace Debugging
+} // namespace QQmlJS
+
+#endif // DEBUGGING_H