File indexing completed on 2024-05-12 15:43:24

 /*
  *  This file is part of the KDE libraries
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
  *  Copyright (C) 2003 Apple Computer, Inc.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Library General Public License for more details.
  *
  *  You should have received a copy of the GNU Library General Public License
  *  along with this library; see the file COPYING.LIB.  If not, write to
  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  *  Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef _KJS_INTERPRETER_H_
 #define _KJS_INTERPRETER_H_
 
 #include "ExecState.h"
 #include "protect.h"
 #include "value.h"
 #include "types.h"
 #include <wtf/HashMap.h>
 
 namespace KJS
 {
 class Debugger;
 class SavedBuiltins;
 class TimeoutChecker;
 class Package;
 class ActivationImp;
 class JSGlobalObject;
 class StringImp;
 
 #if USE(BINDINGS)
 namespace Bindings
 {
 class RootObject;
 }
 #endif
 
 /**
  * Interpreter objects can be used to evaluate ECMAScript code. Each
  * interpreter has a global object which is used for the purposes of code
  * evaluation, and also provides access to built-in properties such as
  * " Object" and "Number".
  */
 class KJS_EXPORT Interpreter
 {
     friend class Collector;
     friend class TimeoutChecker;
 public:
     /**
      * Creates a new interpreter. The supplied object will be used as the global
      * object for all scripts executed with this interpreter. During
      * construction, all the standard properties such as "Object" and "Number"
      * will be added to the global object.
      *
      * Note: You should not use the same global object for multiple
      * interpreters.
      *
      * This is due do the fact that the built-in properties are set in the
      * constructor, and if these objects have been modified from another
      * interpreter (e.g. a script modifying String.prototype), the changes will
      * be overridden.
      *
      * @param globalObject The object to use as the global object for this interpreter
      */
     Interpreter(JSGlobalObject *globalObject);
     /**
      * Creates a new interpreter. A global object will be created and
      * initialized with the standard global properties.
      */
     Interpreter();
 
     /**
      * Returns the object that is used as the global object during all script
      * execution performed by this interpreter
      */
     JSGlobalObject *globalObject() const;
     void initGlobalObject();
 
     /**
      * Returns the execution state object which can be used to execute
      * scripts using this interpreter at a the "global" level, i.e. one
      * with a execution context that has the global object as the "this"
      * value, and who's scope chain contains only the global object.
      *
      * Note: this pointer remains constant for the life of the interpreter
      * and should not be manually deleted.
      *
      * @return The interpreter global execution state object
      */
     virtual ExecState *globalExec();
 
     /**
      * Sets the package instance that will be used to resolve the
      * first level of identifiers of import statements.
      *
      * If no package is set which will make any "import" script
      * statement fail with an error. This is the default in e.g.  a
      * Web browser where package imports should be disabled for
      * security reasons.
      */
     void setGlobalPackage(Package *p);
 
     /**
      * Returns the package that was installed to handle top level
      * package requests. Returns 0, the default, when no package was
      * set.
      *
      * @return The global package
      */
     Package *globalPackage();
 
     /**
      * Parses the supplied ECMAScript code and checks for syntax errors.
      *
      * @param code The code to check
      * @param sourceURL A URL denoting the origin of the code
      * @param startingLineNumber The line offset within an embedding context
      * @return A normal completion if there were no syntax errors in the code,
      * otherwise a throw completion with the syntax error as its value.
      */
     Completion checkSyntax(const UString &sourceURL, int startingLineNumber, const UString &code);
     Completion checkSyntax(const UString &sourceURL, int startingLineNumber, const UChar *code, int codeLength);
 
     /**
      * Evaluates the supplied ECMAScript code.
      *
      * Since this method returns a Completion, you should check the type of
      * completion to detect an error or before attempting to access the returned
      * value. For example, if an error occurs during script execution and is not
      * caught by the script, the completion type will be Throw.
      *
      * If the supplied code is invalid, a SyntaxError will be thrown.
      *
      * @param sourceURL A URL denoting the origin of the code
      * @param startingLineNumber The line offset within an embedding context
      * @param code The code to evaluate
      * @param codeLength The length of the code to evaluate
      * @param thisV The value to pass in as the "this" value for the script
      * execution. This should either be jsNull() or an Object.
      * @return A completion object representing the result of the execution.
      */
     Completion evaluate(const UString &sourceURL, int startingLineNumber, const UChar *code, int codeLength, JSValue *thisV = nullptr);
     Completion evaluate(const UString &sourceURL, int startingLineNumber, const UString &code, JSValue *thisV = nullptr);
 
     /**
      * Pretty-prints the supplied ECMAScript code after checking it
      * for syntax errors.
      *
      * @param sourceURL A URL denoting the origin of the code
      * @param startingLineNumber The line offset within an embedding context
      * @param codeIn The code to check
      * @param codeIn Pointer to string that will contain reformatted code
      *        upon successful parsing.
      * @return A normal completion if there were no syntax errors in the code,
      * otherwise a throw completion with the syntax error as its value.
      */
     static bool normalizeCode(const UString &codeIn, UString *codeOut,
                               int *errLine = nullptr, UString *errMsg = nullptr);
 
     /**
      * Returns the builtin "Object" object. This is the object that was set
      * as a property of the global object during construction; if the property
      * is replaced by script code, this method will still return the original
      * object.
      *
      * @return The builtin "Object" object
      */
     JSObject *builtinObject() const;
 
     /**
      * Returns the builtin "Function" object.
      */
     JSObject *builtinFunction() const;
 
     /**
      * Returns the builtin "Array" object.
      */
     JSObject *builtinArray() const;
 
     /**
      * Returns the builtin "Boolean" object.
      */
     JSObject *builtinBoolean() const;
 
     /**
      * Returns the builtin "String" object.
      */
     JSObject *builtinString() const;
 
     /**
      * Returns the builtin "Number" object.
      */
     JSObject *builtinNumber() const;
 
     /**
      * Returns the builtin "Date" object.
      */
     JSObject *builtinDate() const;
 
     /**
      * Returns the builtin "RegExp" object.
      */
     JSObject *builtinRegExp() const;
 
     /**
      * Returns the builtin "Error" object.
      */
     JSObject *builtinError() const;
 
     /**
      * Returns the builtin "Object.prototype" object.
      */
     JSObject *builtinObjectPrototype() const;
 
     /**
      * Returns the builtin "Function.prototype" object.
      */
     JSObject *builtinFunctionPrototype() const;
 
     /**
      * Returns the builtin "Array.prototype" object.
      */
     JSObject *builtinArrayPrototype() const;
 
     /**
      * Returns the builtin "Boolean.prototype" object.
      */
     JSObject *builtinBooleanPrototype() const;
 
     /**
      * Returns the builtin "String.prototype" object.
      */
     JSObject *builtinStringPrototype() const;
 
     /**
      * Returns the builtin "Number.prototype" object.
      */
     JSObject *builtinNumberPrototype() const;
 
     /**
      * Returns the builtin "Date.prototype" object.
      */
     JSObject *builtinDatePrototype() const;
 
     /**
      * Returns the builtin "RegExp.prototype" object.
      */
     JSObject *builtinRegExpPrototype() const;
 
     /**
      * Returns the builtin "Error.prototype" object.
      */
     JSObject *builtinErrorPrototype() const;
 
     /**
      * The initial value of "Error" global property
      */
     JSObject *builtinEvalError() const;
     JSObject *builtinRangeError() const;
     JSObject *builtinReferenceError() const;
     JSObject *builtinSyntaxError() const;
     JSObject *builtinTypeError() const;
     JSObject *builtinURIError() const;
 
     JSObject *builtinEvalErrorPrototype() const;
     JSObject *builtinRangeErrorPrototype() const;
     JSObject *builtinReferenceErrorPrototype() const;
     JSObject *builtinSyntaxErrorPrototype() const;
     JSObject *builtinTypeErrorPrototype() const;
     JSObject *builtinURIErrorPrototype() const;
 
     enum CompatMode { NativeMode, IECompat, NetscapeCompat };
     /**
      * Call this to enable a compatibility mode with another browser.
      * (by default konqueror is in "native mode").
      * Currently, in KJS, this only changes the behavior of Date::getYear()
      * which returns the full year under IE.
      */
     void setCompatMode(CompatMode mode)
     {
         m_compatMode = mode;
     }
     CompatMode compatMode() const
     {
         return m_compatMode;
     }
 
     /**
      * Run the garbage collection. Returns true when at least one object
      * was collected; false otherwise.
      */
     static bool collect();
 
     /**
      * Called during the mark phase of the garbage collector. Subclasses
      * implementing custom mark methods must make sure to chain to this one.
      */
     virtual void mark(bool currentThreadIsMainThread);
 
     /**
      * This marks all GC heap resources stored as optimizations;
      * and which have their lifetime managed by the appropriate AST.
      * It's static since code can survive the interpreter by a bit.
      */
     static void markSourceCachedObjects();
 
     /**
      * Provides a way to distinguish derived classes.
      * Only useful if you reimplement Interpreter and if different kind of
      * interpreters are created in the same process.
      * The base class returns 0, the ECMA-bindings interpreter returns 1.
      */
     virtual int rtti()
     {
         return 0;
     }
 
     static bool shouldPrintExceptions();
     static void setShouldPrintExceptions(bool);
 
     void saveBuiltins(SavedBuiltins &) const;
     void restoreBuiltins(const SavedBuiltins &);
 
     /**
      * Determine if the it is 'safe' to execute code in the target interpreter from an
      * object that originated in this interpreter.  This check is used to enforce WebCore
      * cross frame security rules.  In particular, attempts to access 'bound' objects are
      * not allowed unless isSafeScript returns true.
      */
     virtual bool isSafeScript(const Interpreter *)
     {
         return true;
     }
 
 #if USE(BINDINGS)
     virtual void *createLanguageInstanceForValue(ExecState *, int language, JSObject *value, const Bindings::RootObject *origin, const Bindings::RootObject *current);
 #endif
 
     // Chained list of interpreters (ring)
     static Interpreter *firstInterpreter()
     {
         return s_hook;
     }
     Interpreter *nextInterpreter() const
     {
         return next;
     }
     Interpreter *prevInterpreter() const
     {
         return prev;
     }
 
     Debugger *debugger() const
     {
         return m_debugger;
     }
     void setDebugger(Debugger *d)
     {
         m_debugger = d;
     }
 
     void setExecState(ExecState *e)
     {
         m_execState = e;
     }
 
     // Note: may be 0, if in globalExec
     ExecState *execState()
     {
         return m_execState ? m_execState : &m_globalExec;
     }
 
     void setTimeoutTime(unsigned timeoutTime)
     {
         m_timeoutTime = timeoutTime;
     }
 
     void startTimeoutCheck();
     void stopTimeoutCheck();
 
     // Resets the timer to full time if it's running
     void restartTimeoutCheck();
 
     void pauseTimeoutCheck();
     void resumeTimeoutCheck();
 
     bool checkTimeout();
 
     void ref()
     {
         ++m_refCount;
     }
     void deref()
     {
         if (--m_refCount <= 0) {
             delete this;
         }
     }
     int refCount() const
     {
         return m_refCount;
     }
 
     unsigned char *stackAlloc(size_t size)
     {
         unsigned char *nextPtr = stackPtr + size;
         if (nextPtr <= stackEnd) {
             unsigned char *toRet = stackPtr;
             stackPtr = nextPtr;
             return toRet;
         }
         return extendStack(size);
     }
 
     void stackFree(size_t size)
     {
         stackPtr -= size;    // ### shrink it?
     }
 
     ActivationImp *getRecycledActivation()
     {
         ActivationImp *out = nullptr;
         if (m_numCachedActivations) {
             m_numCachedActivations--;
             out = m_cachedActivations[m_numCachedActivations];
         }
         return out;
     }
 
     void recycleActivation(ActivationImp *act);
 
     // Global string table management. This is used from StringNode
     // to cache StringImp's for string literals. We keep refcounts
     // to permit multiple ones to use the same value.
     static StringImp *internString(const UString &literal);
     static void releaseInternedString(const UString &literal);
 
     typedef WTF::HashMap<UString::Rep *, std::pair<KJS::StringImp *, int> > InternedStringsTable;
 private:
     static void markInternedStringsTable();
 
     // This creates a table if needed
     static void initInternedStringsTable();
 
     static InternedStringsTable *s_internedStrings;
 
 protected:
     virtual ~Interpreter(); // only deref should delete us
     virtual bool shouldInterruptScript() const
     {
         return true;
     }
 
     long m_timeoutTime;
 
 private:
     bool handleTimeout();
     void init();
     void printException(const Completion &c, const UString &sourceURL);
 
     /**
      * This constructor is not implemented, in order to prevent
      * copy-construction of Interpreter objects. You should always pass around
      * pointers to an interpreter instance instead.
      */
     Interpreter(const Interpreter &);
 
     /**
      * This operator is not implemented, in order to prevent assignment of
      * Interpreter objects. You should always pass around pointers to an
      * interpreter instance instead.
      */
     Interpreter operator=(const Interpreter &);
 
     int m_refCount;
 
     JSGlobalObject *m_globalObject;
     GlobalExecState m_globalExec;
     Package *globPkg;
 
     // Execution stack stuff for this interpreter.
     unsigned char *stackBase; // lowest address in the array
     unsigned char *stackPtr;  // current top/next to allocate
     unsigned char *stackEnd;  // last address in the stack
     unsigned char *extendStack(size_t needed);
 
     // A list of cached activations
     enum {MaxCachedActivations = 32};
 
     ActivationImp *m_cachedActivations[MaxCachedActivations];
     int            m_numCachedActivations;
 
     // Chained list of interpreters (ring) - for collector
     static Interpreter *s_hook;
     Interpreter *next, *prev;
 
     int m_recursion;
 
     Debugger *m_debugger;
     ExecState *m_execState;
     CompatMode m_compatMode;
 
     TimeoutChecker *m_timeoutChecker;
     bool m_timedOut;
 
     unsigned m_startTimeoutCheckCount;
     unsigned m_pauseTimeoutCheckCount;
 
     // Helper for setting constructors, making sure their function names are OK
     void putNamedConstructor(const char *name, JSObject *value);
 
     ProtectedPtr<JSObject> m_Object;
     ProtectedPtr<JSObject> m_Function;
     ProtectedPtr<JSObject> m_Array;
     ProtectedPtr<JSObject> m_Boolean;
     ProtectedPtr<JSObject> m_String;
     ProtectedPtr<JSObject> m_Number;
     ProtectedPtr<JSObject> m_Date;
     ProtectedPtr<JSObject> m_RegExp;
     ProtectedPtr<JSObject> m_Error;
 
     ProtectedPtr<JSObject> m_ObjectPrototype;
     ProtectedPtr<JSObject> m_FunctionPrototype;
     ProtectedPtr<JSObject> m_ArrayPrototype;
     ProtectedPtr<JSObject> m_BooleanPrototype;
     ProtectedPtr<JSObject> m_StringPrototype;
     ProtectedPtr<JSObject> m_NumberPrototype;
     ProtectedPtr<JSObject> m_DatePrototype;
     ProtectedPtr<JSObject> m_RegExpPrototype;
     ProtectedPtr<JSObject> m_ErrorPrototype;
 
     ProtectedPtr<JSObject> m_EvalError;
     ProtectedPtr<JSObject> m_RangeError;
     ProtectedPtr<JSObject> m_ReferenceError;
     ProtectedPtr<JSObject> m_SyntaxError;
     ProtectedPtr<JSObject> m_TypeError;
     ProtectedPtr<JSObject> m_UriError;
 
     ProtectedPtr<JSObject> m_EvalErrorPrototype;
     ProtectedPtr<JSObject> m_RangeErrorPrototype;
     ProtectedPtr<JSObject> m_ReferenceErrorPrototype;
     ProtectedPtr<JSObject> m_SyntaxErrorPrototype;
     ProtectedPtr<JSObject> m_TypeErrorPrototype;
     ProtectedPtr<JSObject> m_UriErrorPrototype;
 };
 
 inline bool Interpreter::checkTimeout()
 {
     if (!m_timedOut) {
         return false;
     }
 
     return handleTimeout();
 }
 
 /**
  * Interface to set enhanced Unicode support functions. By default
  * the interpreter will use the standard C library functions.
  *
  * @internal
  */
 class KJS_EXPORT UnicodeSupport
 {
 public:
     UnicodeSupport();
 
     typedef bool (*CharCategoryFunction)(int c);
     static void setIdentStartChecker(CharCategoryFunction f);
     static void setIdentPartChecker(CharCategoryFunction f);
 
     typedef int (*StringConversionFunction)(uint16_t *str, int strLength,
                                             uint16_t *&destIfNeeded);
     static void setToLowerFunction(StringConversionFunction f);
     static void setToUpperFunction(StringConversionFunction f);
 };
 
 /**
  * Define a Qt-based version of the Unicode support functions.
  *
  * @internal
  */
 #define KJS_QT_UNICODE_IMPL \
     namespace KJS { \
     static bool qtIdentStart(int c) { if (c & 0xffff0000) return false; QChar::Category cat = QChar((unsigned short)c).category(); return cat == QChar::Letter_Uppercase || cat == QChar::Letter_Lowercase || cat == QChar::Letter_Titlecase || cat == QChar::Letter_Modifier || cat == QChar::Letter_Other || c == '$' || c == '_'; } \
     static bool qtIdentPart(int c) { if (c & 0xffff0000) return false; QChar::Category cat = QChar((unsigned short)c).category(); return cat == QChar::Letter_Uppercase || cat == QChar::Letter_Lowercase || cat == QChar::Letter_Titlecase || cat == QChar::Letter_Modifier || cat == QChar::Letter_Other || cat == QChar::Mark_NonSpacing || cat == QChar::Mark_SpacingCombining || cat == QChar::Number_DecimalDigit || cat == QChar::Punctuation_Connector || c == '$' || c == '_'; } \
     static int qtToLower(uint16_t* str, int strLength, uint16_t*& destIfNeeded) { \
         destIfNeeded = 0; \
         for (int i = 0; i < strLength; ++i) \
             str[i] = QChar(str[i]).toLower().unicode(); \
         return strLength; } \
     static int qtToUpper(uint16_t* str, int strLength, uint16_t*& destIfNeeded) { \
         destIfNeeded = 0; \
         for (int i = 0; i < strLength; ++i) \
             str[i] = QChar(str[i]).toUpper().unicode(); \
         return strLength; } \
     }
 
 /**
  * Set the Qt-based version of the Unicode support functions.
  *
  * @internal
  */
 #define KJS_QT_UNICODE_SET \
     { KJS::UnicodeSupport::setIdentStartChecker(KJS::qtIdentStart); \
         KJS::UnicodeSupport::setIdentPartChecker(KJS::qtIdentPart); \
         KJS::UnicodeSupport::setToLowerFunction(KJS::qtToLower); \
         KJS::UnicodeSupport::setToUpperFunction(KJS::qtToUpper); }
 
 } // namespace
 
 #endif // _KJS_INTERPRETER_H_