Add a MemoryManager, which does GC for the interpreter.

Todo:
- stack walking for MASM
- fix all TODOs/FIXMEs and hidden treasures (bugs).

Change-Id: I36f8cdc3a545df7287ce1df17b3570a9c017865e
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

4 files changed, 169 insertions, 16 deletions

diff --git a/moth/moth.pri b/moth/moth.pri
index 4381c9a53b..160c1aac00 100644
--- a/moth/moth.pri
+++ b/moth/moth.pri
@@ -4,10 +4,12 @@ HEADERS += \
     $$PWD/qv4isel_moth_p.h \
     $$PWD/qv4instr_moth_p.h \
     $$PWD/qv4vme_moth_p.h \
+    $$PWD/qv4mm_moth.h
 
 SOURCES += \
     $$PWD/qv4isel_moth.cpp \
     $$PWD/qv4instr_moth.cpp \
     $$PWD/qv4vme_moth.cpp \
+    $$PWD/qv4mm_moth.cpp
 
 #DEFINES += DO_TRACE_INSTR
diff --git a/moth/qv4mm_moth.cpp b/moth/qv4mm_moth.cpp
new file mode 100644
index 0000000000..44e45fe027
--- /dev/null
+++ b/moth/qv4mm_moth.cpp
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** 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 "qmljs_engine.h"
+#include "qv4mm_moth.h"
+
+#include <QList>
+
+using namespace QQmlJS;
+using namespace QQmlJS::Moth;
+
+MemoryManager::MemoryManager()
+{
+    stackFrames.reserve(64);
+}
+
+MemoryManager::~MemoryManager()
+{
+}
+
+VM::Value *MemoryManager::allocStackFrame(std::size_t frameSize)
+{
+    std::size_t size = frameSize * sizeof(VM::Value);
+    MMObject *m = alloc(align(size));
+    stackFrames.append(m);
+    return reinterpret_cast<VM::Value *>(&m->data);
+}
+
+void MemoryManager::deallocStackFrame(VM::Value *stackFrame)
+{
+    MMObject *o = toObject(stackFrame);
+    for (int i = stackFrames.size() - 1; i >= 0; --i) {
+        if (stackFrames[i] == o) {
+            stackFrames.remove(i);
+            dealloc(o);
+            return;
+        }
+    }
+
+    Q_UNREACHABLE();
+}
+
+void MemoryManager::collectRootsOnStack(QVector<VM::Object *> &roots) const
+{
+    for (int i = 0, ei = stackFrames.size(); i < ei; ++i) {
+        MMObject *m = stackFrames[i];
+        VM::Value *frame = reinterpret_cast<VM::Value *>(&m->data);
+        std::size_t frameSize = (m->info.size - align(sizeof(MMInfo))) / sizeof(VM::Value);
+        for (std::size_t j = 0; j < frameSize; ++j) {
+            if (VM::Object *o = frame[j].asObject()) {
+                roots.append(o);
+            }
+        }
+    }
+}
diff --git a/moth/qv4mm_moth.h b/moth/qv4mm_moth.h
new file mode 100644
index 0000000000..a2b1ebd556
--- /dev/null
+++ b/moth/qv4mm_moth.h
@@ -0,0 +1,59 @@
+/****************************************************************************
+**
+** 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 QV4GC_MOTH_H
+#define QV4GC_MOTH_H
+
+#include "qv4mm.h"
+
+#include <QVector>
+
+namespace QQmlJS {
+namespace Moth {
+
+class MemoryManager: public QQmlJS::VM::MemoryManager
+{
+public:
+    MemoryManager();
+    ~MemoryManager();
+
+    VM::Value *allocStackFrame(std::size_t frameSize);
+    void deallocStackFrame(VM::Value *stackFrame);
+
+protected:
+    virtual void collectRootsOnStack(QVector<VM::Object *> &roots) const;
+
+private:
+    QVector<MMObject *> stackFrames;
+};
+
+} // namespace Moth
+} // namespace QQmlJS
+
+#endif // QV4GC_MOTH_H
diff --git a/moth/qv4vme_moth.cpp b/moth/qv4vme_moth.cpp
index d38d7d7cb7..86b396f422 100644
--- a/moth/qv4vme_moth.cpp
+++ b/moth/qv4vme_moth.cpp
@@ -2,6 +2,7 @@
 #include "qv4instr_moth_p.h"
 #include "qmljs_value.h"
 #include "debugging.h"
+#include "qv4mm_moth.h"
 
 #include <iostream>
 
@@ -51,7 +52,7 @@ using namespace QQmlJS::Moth;
 
 #endif
 
-static inline VM::Value *tempValue(QQmlJS::VM::ExecutionContext *context, QVector<VM::Value> &stack, int index)
+static inline VM::Value *tempValue(QQmlJS::VM::ExecutionContext *context, VM::Value* stack, int index)
 {
 #ifdef DO_TRACE_INSTR
     const char *kind;
@@ -87,25 +88,32 @@ static inline VM::Value *tempValue(QQmlJS::VM::ExecutionContext *context, QVecto
         int off = index - context->variableCount();
 
         Q_ASSERT(off >= 0);
-        Q_ASSERT(off < stack.size());
 
-        return stack.data() + off;
+        return stack + off;
     }
 }
 
 class FunctionState: public Debugging::FunctionState
 {
 public:
-    FunctionState(QQmlJS::VM::ExecutionContext *context, QVector<VM::Value> *stack, const uchar **code)
+    FunctionState(QQmlJS::VM::ExecutionContext *context, const uchar **code)
         : Debugging::FunctionState(context)
-        , stack(stack)
+        , stack(0)
+        , stackSize(0)
         , code(code)
     {}
 
-    virtual VM::Value *temp(unsigned idx) { return stack->data() + idx; }
+    ~FunctionState()
+    { if (stack) static_cast<MemoryManager *>(context()->engine->memoryManager)->deallocStackFrame(stack); }
+
+    virtual VM::Value *temp(unsigned idx) { return stack + idx; }
+
+    void setStack(VM::Value *stack, unsigned stackSize)
+    { this->stack = stack; this->stackSize = stackSize; }
 
 private:
-    QVector<VM::Value> *stack;
+    VM::Value *stack;
+    unsigned stackSize;
     const uchar **code;
 };
 
@@ -130,8 +138,9 @@ VM::Value VME::operator()(QQmlJS::VM::ExecutionContext *context, const uchar *co
     }
 #endif
 
-    QVector<VM::Value> stack;
-    FunctionState state(context, &stack, &code);
+    VM::Value *stack = 0;
+    unsigned stackSize = 0;
+    FunctionState state(context, &code);
 
 #ifdef MOTH_THREADED_INTERPRETER
     const Instr *genericInstr = reinterpret_cast<const Instr *>(code);
@@ -191,7 +200,9 @@ VM::Value VME::operator()(QQmlJS::VM::ExecutionContext *context, const uchar *co
 
     MOTH_BEGIN_INSTR(Push)
         TRACE(inline, "stack size: %u", instr.value);
-        stack.resize(instr.value);
+        stackSize = instr.value;
+        stack = static_cast<MemoryManager *>(context->engine->memoryManager)->allocStackFrame(stackSize);
+        state.setStack(stack, stackSize);
     MOTH_END_INSTR(Push)
 
     MOTH_BEGIN_INSTR(CallValue)
@@ -207,20 +218,20 @@ VM::Value VME::operator()(QQmlJS::VM::ExecutionContext *context, const uchar *co
 #endif // DO_TRACE_INSTR
         quint32 argStart = instr.args - context->variableCount();
         TRACE(Call, "value index = %d, argStart = %d, argc = %d, result temp index = %d", instr.destIndex, argStart, instr.argc, instr.targetTempIndex);
-        VM::Value *args = stack.data() + argStart;
+        VM::Value *args = stack + argStart;
         TEMP(instr.targetTempIndex) = __qmljs_call_value(context, VM::Value::undefinedValue(), TEMP(instr.destIndex), args, instr.argc);
     MOTH_END_INSTR(CallValue)
 
     MOTH_BEGIN_INSTR(CallProperty)
         quint32 argStart = instr.args - context->variableCount();
-        VM::Value *args = stack.data() + argStart;
+        VM::Value *args = stack + argStart;
         VM::Value base = TEMP(instr.baseTemp);
         TEMP(instr.targetTempIndex) = __qmljs_call_property(context, base, instr.name, args, instr.argc);
     MOTH_END_INSTR(CallProperty)
 
     MOTH_BEGIN_INSTR(CallBuiltin)
         quint32 argStart = instr.args - context->variableCount();
-        VM::Value *args = stack.data() + argStart;
+        VM::Value *args = stack + argStart;
         void *buf;
         switch (instr.builtin) {
         case Instr::instr_callBuiltin::builtin_typeof:
@@ -300,20 +311,20 @@ VM::Value VME::operator()(QQmlJS::VM::ExecutionContext *context, const uchar *co
 
     MOTH_BEGIN_INSTR(CreateValue)
         quint32 argStart = instr.args - context->variableCount();
-        VM::Value *args = stack.data() + argStart;
+        VM::Value *args = stack + argStart;
         TEMP(instr.targetTempIndex) = __qmljs_construct_value(context, TEMP(instr.func), args, instr.argc);
     MOTH_END_INSTR(CreateValue)
 
     MOTH_BEGIN_INSTR(CreateProperty)
         quint32 argStart = instr.args - context->variableCount();
-        VM::Value *args = stack.data() + argStart;
+        VM::Value *args = stack + argStart;
         TEMP(instr.targetTempIndex) = __qmljs_construct_property(context, TEMP(instr.base), instr.name, args, instr.argc);
     MOTH_END_INSTR(CreateProperty)
 
     MOTH_BEGIN_INSTR(CreateActivationProperty)
         TRACE(inline, "property name = %s, argc = %d", instr.name->toQString().toUtf8().constData(), instr.argc);
         quint32 argStart = instr.args - context->variableCount();
-        VM::Value *args = stack.data() + argStart;
+        VM::Value *args = stack + argStart;
         TEMP(instr.targetTempIndex) = __qmljs_construct_activation_property(context, instr.name, args, instr.argc);
     MOTH_END_INSTR(CreateActivationProperty)