duke@435: /* trims@2708: * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: stefank@2314: #ifndef SHARE_VM_UTILITIES_EXCEPTIONS_HPP stefank@2314: #define SHARE_VM_UTILITIES_EXCEPTIONS_HPP stefank@2314: stefank@2314: #include "memory/allocation.hpp" stefank@2314: #include "oops/oopsHierarchy.hpp" stefank@2314: #include "utilities/sizes.hpp" stefank@2314: duke@435: // This file provides the basic support for exception handling in the VM. duke@435: // Note: We do not use C++ exceptions to avoid compiler dependencies and duke@435: // unpredictable performance. duke@435: // duke@435: // Scheme: Exceptions are stored with the thread. There is never more duke@435: // than one pending exception per thread. All functions that can throw duke@435: // an exception carry a THREAD argument (usually the last argument and duke@435: // declared with the TRAPS macro). Throwing an exception means setting duke@435: // a pending exception in the thread. Upon return from a function that duke@435: // can throw an exception, we must check if an exception is pending. duke@435: // The CHECK macros do this in a convenient way. Carrying around the duke@435: // thread provides also convenient access to it (e.g. for Handle duke@435: // creation, w/o the need for recomputation). duke@435: duke@435: duke@435: duke@435: // Forward declarations to be independent of the include structure. duke@435: // This allows us to have exceptions.hpp included in top.hpp. duke@435: duke@435: class Thread; duke@435: class Handle; coleenp@2497: class Symbol; duke@435: class JavaCallArguments; duke@435: duke@435: // The ThreadShadow class is a helper class to access the _pending_exception duke@435: // field of the Thread class w/o having access to the Thread's interface (for duke@435: // include hierachy reasons). duke@435: duke@435: class ThreadShadow: public CHeapObj { duke@435: protected: duke@435: oop _pending_exception; // Thread has gc actions. duke@435: const char* _exception_file; // file information for exception (debugging only) duke@435: int _exception_line; // line information for exception (debugging only) duke@435: friend void check_ThreadShadow(); // checks _pending_exception offset duke@435: duke@435: // The following virtual exists only to force creation of a vtable. duke@435: // We need ThreadShadow to have a vtable, even in product builds, duke@435: // so that its layout will start at an offset of zero relative to Thread. duke@435: // Some C++ compilers are so "clever" that they put the ThreadShadow duke@435: // base class at offset 4 in Thread (after Thread's vtable), if they duke@435: // notice that Thread has a vtable but ThreadShadow does not. duke@435: virtual void unused_initial_virtual() { } duke@435: duke@435: public: duke@435: oop pending_exception() const { return _pending_exception; } duke@435: bool has_pending_exception() const { return _pending_exception != NULL; } duke@435: const char* exception_file() const { return _exception_file; } duke@435: int exception_line() const { return _exception_line; } duke@435: duke@435: // Code generation support duke@435: static ByteSize pending_exception_offset() { return byte_offset_of(ThreadShadow, _pending_exception); } duke@435: duke@435: // use THROW whenever possible! duke@435: void set_pending_exception(oop exception, const char* file, int line); duke@435: duke@435: // use CLEAR_PENDING_EXCEPTION whenever possible! duke@435: void clear_pending_exception(); duke@435: duke@435: ThreadShadow() : _pending_exception(NULL), duke@435: _exception_file(NULL), _exception_line(0) {} duke@435: }; duke@435: duke@435: duke@435: // Exceptions is a helper class that encapsulates all operations duke@435: // that require access to the thread interface and which are duke@435: // relatively rare. The Exceptions operations should only be duke@435: // used directly if the macros below are insufficient. duke@435: duke@435: class Exceptions { duke@435: static bool special_exception(Thread *thread, const char* file, int line, Handle exception); coleenp@2497: static bool special_exception(Thread* thread, const char* file, int line, Symbol* name, const char* message); duke@435: public: duke@435: // this enum is defined to indicate whether it is safe to duke@435: // ignore the encoding scheme of the original message string. duke@435: typedef enum { duke@435: safe_to_utf8 = 0, duke@435: unsafe_to_utf8 = 1 duke@435: } ExceptionMsgToUtf8Mode; duke@435: // Throw exceptions: w/o message, w/ message & with formatted message. duke@435: static void _throw_oop(Thread* thread, const char* file, int line, oop exception); never@1446: static void _throw(Thread* thread, const char* file, int line, Handle exception, const char* msg = NULL); duke@435: static void _throw_msg(Thread* thread, const char* file, int line, coleenp@2497: Symbol* name, const char* message, Handle loader, duke@435: Handle protection_domain); duke@435: static void _throw_msg(Thread* thread, const char* file, int line, coleenp@2497: Symbol* name, const char* message); duke@435: static void _throw_args(Thread* thread, const char* file, int line, coleenp@2497: Symbol* name, Symbol* signature, duke@435: JavaCallArguments* args); duke@435: static void _throw_msg_cause(Thread* thread, const char* file, coleenp@2497: int line, Symbol* h_name, const char* message, duke@435: Handle h_cause, Handle h_loader, Handle h_protection_domain); duke@435: static void _throw_msg_cause(Thread* thread, const char* file, int line, coleenp@2497: Symbol* name, const char* message, Handle cause); duke@435: duke@435: // There is no THROW... macro for this method. Caller should remember duke@435: // to do a return after calling it. coleenp@2497: static void fthrow(Thread* thread, const char* file, int line, Symbol* name, duke@435: const char* format, ...); duke@435: duke@435: // Create and initialize a new exception coleenp@2497: static Handle new_exception(Thread* thread, Symbol* name, coleenp@2497: Symbol* signature, JavaCallArguments* args, duke@435: Handle cause, Handle loader, duke@435: Handle protection_domain); duke@435: coleenp@2497: static Handle new_exception(Thread* thread, Symbol* name, duke@435: const char* message, Handle cause, Handle loader, duke@435: Handle protection_domain, duke@435: ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8); duke@435: coleenp@2497: static Handle new_exception(Thread* thread, Symbol* name, duke@435: const char* message, duke@435: ExceptionMsgToUtf8Mode to_utf8_safe = safe_to_utf8); duke@435: duke@435: static void throw_stack_overflow_exception(Thread* thread, const char* file, int line); duke@435: duke@435: // for AbortVMOnException flag kvn@2039: NOT_PRODUCT(static void debug_check_abort(Handle exception, const char* message = NULL);) kvn@2039: NOT_PRODUCT(static void debug_check_abort(const char *value_string, const char* message = NULL);) duke@435: }; duke@435: duke@435: duke@435: // The THREAD & TRAPS macros facilitate the declaration of functions that throw exceptions. duke@435: // Convention: Use the TRAPS macro as the last argument of such a function; e.g.: duke@435: // duke@435: // int this_function_may_trap(int x, float y, TRAPS) duke@435: duke@435: #define THREAD __the_thread__ duke@435: #define TRAPS Thread* THREAD duke@435: duke@435: duke@435: // The CHECK... macros should be used to pass along a THREAD reference and to check for pending duke@435: // exceptions. In special situations it is necessary to handle pending exceptions explicitly, duke@435: // in these cases the PENDING_EXCEPTION helper macros should be used. duke@435: // duke@435: // Macro naming conventions: Macros that end with _ require a result value to be returned. They duke@435: // are for functions with non-void result type. The result value is usually ignored because of duke@435: // the exception and is only needed for syntactic correctness. The _0 ending is a shortcut for duke@435: // _(0) since this is a frequent case. Example: duke@435: // duke@435: // int result = this_function_may_trap(x_arg, y_arg, CHECK_0); duke@435: // duke@435: // CAUTION: make sure that the function call using a CHECK macro is not the only statement of a duke@435: // conditional branch w/o enclosing {} braces, since the CHECK macros expand into several state- duke@435: // ments! duke@435: duke@435: #define PENDING_EXCEPTION (((ThreadShadow*)THREAD)->pending_exception()) duke@435: #define HAS_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->has_pending_exception()) duke@435: #define CLEAR_PENDING_EXCEPTION (((ThreadShadow*)THREAD)->clear_pending_exception()) duke@435: duke@435: #define CHECK THREAD); if (HAS_PENDING_EXCEPTION) return ; (0 duke@435: #define CHECK_(result) THREAD); if (HAS_PENDING_EXCEPTION) return result; (0 duke@435: #define CHECK_0 CHECK_(0) duke@435: #define CHECK_NH CHECK_(Handle()) duke@435: #define CHECK_NULL CHECK_(NULL) duke@435: #define CHECK_false CHECK_(false) duke@435: duke@435: // The THROW... macros should be used to throw an exception. They require a THREAD variable to be duke@435: // visible within the scope containing the THROW. Usually this is achieved by declaring the function duke@435: // with a TRAPS argument. duke@435: duke@435: #define THREAD_AND_LOCATION THREAD, __FILE__, __LINE__ duke@435: duke@435: #define THROW_OOP(e) \ duke@435: { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return; } duke@435: duke@435: #define THROW_HANDLE(e) \ duke@435: { Exceptions::_throw(THREAD_AND_LOCATION, e); return; } duke@435: duke@435: #define THROW(name) \ duke@435: { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return; } duke@435: duke@435: #define THROW_MSG(name, message) \ duke@435: { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return; } duke@435: duke@435: #define THROW_MSG_LOADER(name, message, loader, protection_domain) \ duke@435: { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return; } duke@435: duke@435: #define THROW_ARG(name, signature, args) \ duke@435: { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return; } duke@435: duke@435: #define THROW_OOP_(e, result) \ duke@435: { Exceptions::_throw_oop(THREAD_AND_LOCATION, e); return result; } duke@435: duke@435: #define THROW_HANDLE_(e, result) \ duke@435: { Exceptions::_throw(THREAD_AND_LOCATION, e); return result; } duke@435: duke@435: #define THROW_(name, result) \ duke@435: { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, NULL); return result; } duke@435: duke@435: #define THROW_MSG_(name, message, result) \ duke@435: { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message); return result; } duke@435: duke@435: #define THROW_MSG_LOADER_(name, message, loader, protection_domain, result) \ duke@435: { Exceptions::_throw_msg(THREAD_AND_LOCATION, name, message, loader, protection_domain); return result; } duke@435: duke@435: #define THROW_ARG_(name, signature, args, result) \ duke@435: { Exceptions::_throw_args(THREAD_AND_LOCATION, name, signature, args); return result; } duke@435: duke@435: #define THROW_MSG_CAUSE_(name, message, cause, result) \ duke@435: { Exceptions::_throw_msg_cause(THREAD_AND_LOCATION, name, message, cause); return result; } duke@435: duke@435: duke@435: #define THROW_OOP_0(e) THROW_OOP_(e, 0) duke@435: #define THROW_HANDLE_0(e) THROW_HANDLE_(e, 0) duke@435: #define THROW_0(name) THROW_(name, 0) duke@435: #define THROW_MSG_0(name, message) THROW_MSG_(name, message, 0) duke@435: #define THROW_WRAPPED_0(name, oop_to_wrap) THROW_WRAPPED_(name, oop_to_wrap, 0) duke@435: #define THROW_ARG_0(name, signature, arg) THROW_ARG_(name, signature, arg, 0) duke@435: #define THROW_MSG_CAUSE_0(name, message, cause) THROW_MSG_CAUSE_(name, message, cause, 0) duke@435: jrose@1145: #define THROW_NULL(name) THROW_(name, NULL) jrose@1145: #define THROW_MSG_NULL(name, message) THROW_MSG_(name, message, NULL) jrose@1145: duke@435: // The CATCH macro checks that no exception has been thrown by a function; it is used at duke@435: // call sites about which is statically known that the callee cannot throw an exception duke@435: // even though it is declared with TRAPS. duke@435: duke@435: #define CATCH \ duke@435: THREAD); if (HAS_PENDING_EXCEPTION) { \ duke@435: oop ex = PENDING_EXCEPTION; \ duke@435: CLEAR_PENDING_EXCEPTION; \ duke@435: ex->print(); \ duke@435: ShouldNotReachHere(); \ duke@435: } (0 duke@435: duke@435: duke@435: // ExceptionMark is a stack-allocated helper class for local exception handling. duke@435: // It is used with the EXCEPTION_MARK macro. duke@435: duke@435: class ExceptionMark { duke@435: private: duke@435: Thread* _thread; duke@435: duke@435: public: duke@435: ExceptionMark(Thread*& thread); duke@435: ~ExceptionMark(); duke@435: }; duke@435: duke@435: duke@435: duke@435: // Use an EXCEPTION_MARK for 'local' exceptions. EXCEPTION_MARK makes sure that no duke@435: // pending exception exists upon entering its scope and tests that no pending exception duke@435: // exists when leaving the scope. duke@435: duke@435: // See also preserveException.hpp for PRESERVE_EXCEPTION_MARK macro, duke@435: // which preserves pre-existing exceptions and does not allow new duke@435: // exceptions. duke@435: duke@435: #define EXCEPTION_MARK Thread* THREAD; ExceptionMark __em(THREAD); stefank@2314: stefank@2314: #endif // SHARE_VM_UTILITIES_EXCEPTIONS_HPP