Libraries: Move to Userland/Libraries/

Userland/Libraries/LibJS/Runtime/VM.h

@@ -0,0 +1,290 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/FlyString.h>
+#include <AK/HashMap.h>
+#include <AK/RefCounted.h>
+#include <AK/StackInfo.h>
+#include <LibJS/Heap/Heap.h>
+#include <LibJS/Runtime/CommonPropertyNames.h>
+#include <LibJS/Runtime/Error.h>
+#include <LibJS/Runtime/ErrorTypes.h>
+#include <LibJS/Runtime/Exception.h>
+#include <LibJS/Runtime/MarkedValueList.h>
+#include <LibJS/Runtime/Value.h>
+
+namespace JS {
+
+enum class ScopeType {
+    None,
+    Function,
+    Block,
+    Try,
+    Breakable,
+    Continuable,
+};
+
+struct ScopeFrame {
+    ScopeType type;
+    NonnullRefPtr<ScopeNode> scope_node;
+    bool pushed_environment { false };
+};
+
+struct CallFrame {
+    FlyString function_name;
+    Value this_value;
+    Vector<Value> arguments;
+    Array* arguments_object { nullptr };
+    ScopeObject* scope { nullptr };
+    bool is_strict_mode { false };
+};
+
+class VM : public RefCounted<VM> {
+public:
+    static NonnullRefPtr<VM> create();
+    ~VM();
+
+    bool should_log_exceptions() const { return m_should_log_exceptions; }
+    void set_should_log_exceptions(bool b) { m_should_log_exceptions = b; }
+
+    Heap& heap() { return m_heap; }
+    const Heap& heap() const { return m_heap; }
+
+    Interpreter& interpreter();
+    Interpreter* interpreter_if_exists();
+
+    void push_interpreter(Interpreter&);
+    void pop_interpreter(Interpreter&);
+
+    Exception* exception()
+    {
+        return m_exception;
+    }
+
+    void clear_exception() { m_exception = nullptr; }
+
+    class InterpreterExecutionScope {
+    public:
+        InterpreterExecutionScope(Interpreter&);
+        ~InterpreterExecutionScope();
+
+    private:
+        Interpreter& m_interpreter;
+    };
+
+    void gather_roots(HashTable<Cell*>&);
+
+#define __JS_ENUMERATE(SymbolName, snake_name) \
+    Symbol* well_known_symbol_##snake_name() const { return m_well_known_symbol_##snake_name; }
+    JS_ENUMERATE_WELL_KNOWN_SYMBOLS
+#undef __JS_ENUMERATE
+
+    Symbol* get_global_symbol(const String& description);
+
+    PrimitiveString& empty_string() { return *m_empty_string; }
+    PrimitiveString& single_ascii_character_string(u8 character)
+    {
+        ASSERT(character < 0x80);
+        return *m_single_ascii_character_strings[character];
+    }
+
+    void push_call_frame(CallFrame& call_frame, GlobalObject& global_object)
+    {
+        ASSERT(!exception());
+        // Ensure we got some stack space left, so the next function call doesn't kill us.
+        // This value is merely a guess and might need tweaking at a later point.
+        if (m_stack_info.size_free() < 16 * KiB)
+            throw_exception<Error>(global_object, "RuntimeError", "Call stack size limit exceeded");
+        else
+            m_call_stack.append(&call_frame);
+    }
+
+    void pop_call_frame() { m_call_stack.take_last(); }
+
+    void push_ast_node(const ASTNode& node) { m_ast_nodes.append(&node); }
+    void pop_ast_node() { m_ast_nodes.take_last(); }
+
+    CallFrame& call_frame() { return *m_call_stack.last(); }
+    const CallFrame& call_frame() const { return *m_call_stack.last(); }
+    const Vector<CallFrame*>& call_stack() const { return m_call_stack; }
+    Vector<CallFrame*>& call_stack() { return m_call_stack; }
+    const Vector<const ASTNode*>& node_stack() const { return m_ast_nodes; }
+
+    const ScopeObject* current_scope() const { return call_frame().scope; }
+    ScopeObject* current_scope() { return call_frame().scope; }
+
+    bool in_strict_mode() const;
+
+    template<typename Callback>
+    void for_each_argument(Callback callback)
+    {
+        if (m_call_stack.is_empty())
+            return;
+        for (auto& value : call_frame().arguments)
+            callback(value);
+    }
+
+    size_t argument_count() const
+    {
+        if (m_call_stack.is_empty())
+            return 0;
+        return call_frame().arguments.size();
+    }
+
+    Value argument(size_t index) const
+    {
+        if (m_call_stack.is_empty())
+            return {};
+        auto& arguments = call_frame().arguments;
+        return index < arguments.size() ? arguments[index] : js_undefined();
+    }
+
+    Value this_value(Object& global_object) const
+    {
+        if (m_call_stack.is_empty())
+            return &global_object;
+        return call_frame().this_value;
+    }
+
+    Value last_value() const { return m_last_value; }
+    void set_last_value(Badge<Interpreter>, Value value) { m_last_value = value; }
+
+    const StackInfo& stack_info() const { return m_stack_info; };
+
+    bool underscore_is_last_value() const { return m_underscore_is_last_value; }
+    void set_underscore_is_last_value(bool b) { m_underscore_is_last_value = b; }
+
+    void unwind(ScopeType type, FlyString label = {})
+    {
+        m_unwind_until = type;
+        m_unwind_until_label = label;
+    }
+    void stop_unwind() { m_unwind_until = ScopeType::None; }
+    bool should_unwind_until(ScopeType type, FlyString label = {}) const
+    {
+        if (m_unwind_until_label.is_null())
+            return m_unwind_until == type;
+        return m_unwind_until == type && m_unwind_until_label == label;
+    }
+    bool should_unwind() const { return m_unwind_until != ScopeType::None; }
+
+    ScopeType unwind_until() const { return m_unwind_until; }
+
+    Value get_variable(const FlyString& name, GlobalObject&);
+    void set_variable(const FlyString& name, Value, GlobalObject&, bool first_assignment = false);
+
+    Reference get_reference(const FlyString& name);
+
+    template<typename T, typename... Args>
+    void throw_exception(GlobalObject& global_object, Args&&... args)
+    {
+        return throw_exception(global_object, T::create(global_object, forward<Args>(args)...));
+    }
+
+    void throw_exception(Exception*);
+    void throw_exception(GlobalObject& global_object, Value value)
+    {
+        return throw_exception(heap().allocate<Exception>(global_object, value));
+    }
+
+    template<typename T, typename... Args>
+    void throw_exception(GlobalObject& global_object, ErrorType type, Args&&... args)
+    {
+        return throw_exception(global_object, T::create(global_object, String::formatted(type.message(), forward<Args>(args)...)));
+    }
+
+    Value construct(Function&, Function& new_target, Optional<MarkedValueList> arguments, GlobalObject&);
+
+    String join_arguments() const;
+
+    Value resolve_this_binding(GlobalObject&) const;
+    const ScopeObject* find_this_scope() const;
+    Value get_new_target() const;
+
+    template<typename... Args>
+    [[nodiscard]] ALWAYS_INLINE Value call(Function& function, Value this_value, Args... args)
+    {
+        if constexpr (sizeof...(Args) > 0) {
+            MarkedValueList arglist { heap() };
+            (..., arglist.append(move(args)));
+            return call(function, this_value, move(arglist));
+        }
+
+        return call(function, this_value);
+    }
+
+    CommonPropertyNames names;
+
+    Shape& scope_object_shape() { return *m_scope_object_shape; }
+
+private:
+    VM();
+
+    [[nodiscard]] Value call_internal(Function&, Value this_value, Optional<MarkedValueList> arguments);
+
+    Exception* m_exception { nullptr };
+
+    Heap m_heap;
+    Vector<Interpreter*> m_interpreters;
+
+    Vector<CallFrame*> m_call_stack;
+    Vector<const ASTNode*> m_ast_nodes;
+
+    Value m_last_value;
+    ScopeType m_unwind_until { ScopeType::None };
+    FlyString m_unwind_until_label;
+
+    StackInfo m_stack_info;
+
+    bool m_underscore_is_last_value { false };
+
+    HashMap<String, Symbol*> m_global_symbol_map;
+
+    PrimitiveString* m_empty_string { nullptr };
+    PrimitiveString* m_single_ascii_character_strings[128] {};
+
+#define __JS_ENUMERATE(SymbolName, snake_name) \
+    Symbol* m_well_known_symbol_##snake_name { nullptr };
+    JS_ENUMERATE_WELL_KNOWN_SYMBOLS
+#undef __JS_ENUMERATE
+
+    Shape* m_scope_object_shape { nullptr };
+
+    bool m_should_log_exceptions { false };
+};
+
+template<>
+[[nodiscard]] ALWAYS_INLINE Value VM::call(Function& function, Value this_value, MarkedValueList arguments) { return call_internal(function, this_value, move(arguments)); }
+
+template<>
+[[nodiscard]] ALWAYS_INLINE Value VM::call(Function& function, Value this_value, Optional<MarkedValueList> arguments) { return call_internal(function, this_value, move(arguments)); }
+
+template<>
+[[nodiscard]] ALWAYS_INLINE Value VM::call(Function& function, Value this_value) { return call(function, this_value, Optional<MarkedValueList> {}); }
+
+}