/*
* Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#ifdef COMPILER2
#include "asm/assembler.hpp"
#include "assembler_x86.inline.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/vmreg.hpp"
#include "interpreter/interpreter.hpp"
#include "nativeInst_x86.hpp"
#include "opto/runtime.hpp"
#include "runtime/interfaceSupport.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/vframeArray.hpp"
#include "utilities/globalDefinitions.hpp"
#include "vmreg_x86.inline.hpp"
#endif
#define __ masm->
//------------------------------generate_exception_blob---------------------------
// creates exception blob at the end
// Using exception blob, this code is jumped from a compiled method.
//
// Given an exception pc at a call we call into the runtime for the
// handler in this method. This handler might merely restore state
// (i.e. callee save registers) unwind the frame and jump to the
// exception handler for the nmethod if there is no Java level handler
// for the nmethod.
//
// This code is entered with a jmp.
//
// Arguments:
// rax: exception oop
// rdx: exception pc
//
// Results:
// rax: exception oop
// rdx: exception pc in caller or ???
// destination: exception handler of caller
//
// Note: the exception pc MUST be at a call (precise debug information)
// Only register rax, rdx, rcx are not callee saved.
//
void OptoRuntime::generate_exception_blob() {
// Capture info about frame layout
enum layout {
thread_off, // last_java_sp
// The frame sender code expects that rbp will be in the "natural" place and
// will override any oopMap setting for it. We must therefore force the layout
// so that it agrees with the frame sender code.
rbp_off,
return_off, // slot for return address
framesize
};
// allocate space for the code
ResourceMark rm;
// setup code generation tools
CodeBuffer buffer("exception_blob", 512, 512);
MacroAssembler* masm = new MacroAssembler(&buffer);
OopMapSet *oop_maps = new OopMapSet();
address start = __ pc();
__ push(rdx);
__ subptr(rsp, return_off * wordSize); // Prolog!
// rbp, location is implicitly known
__ movptr(Address(rsp,rbp_off *wordSize), rbp);
// Store exception in Thread object. We cannot pass any arguments to the
// handle_exception call, since we do not want to make any assumption
// about the size of the frame where the exception happened in.
__ get_thread(rcx);
__ movptr(Address(rcx, JavaThread::exception_oop_offset()), rax);
__ movptr(Address(rcx, JavaThread::exception_pc_offset()), rdx);
// This call does all the hard work. It checks if an exception handler
// exists in the method.
// If so, it returns the handler address.
// If not, it prepares for stack-unwinding, restoring the callee-save
// registers of the frame being removed.
//
__ movptr(Address(rsp, thread_off * wordSize), rcx); // Thread is first argument
__ set_last_Java_frame(rcx, noreg, noreg, NULL);
__ call(RuntimeAddress(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C)));
// No registers to map, rbp is known implicitly
oop_maps->add_gc_map( __ pc() - start, new OopMap( framesize, 0 ));
__ get_thread(rcx);
__ reset_last_Java_frame(rcx, false, false);
// Restore callee-saved registers
__ movptr(rbp, Address(rsp, rbp_off * wordSize));
__ addptr(rsp, return_off * wordSize); // Epilog!
__ pop(rdx); // Exception pc
// rax: exception handler for given <exception oop/exception pc>
// Restore SP from BP if the exception PC is a MethodHandle call site.
__ cmpl(Address(rcx, JavaThread::is_method_handle_return_offset()), 0);
__ cmovptr(Assembler::notEqual, rsp, rbp_mh_SP_save);
// We have a handler in rax, (could be deopt blob)
// rdx - throwing pc, deopt blob will need it.
__ push(rax);
// Get the exception
__ movptr(rax, Address(rcx, JavaThread::exception_oop_offset()));
// Get the exception pc in case we are deoptimized
__ movptr(rdx, Address(rcx, JavaThread::exception_pc_offset()));
#ifdef ASSERT
__ movptr(Address(rcx, JavaThread::exception_handler_pc_offset()), NULL_WORD);
__ movptr(Address(rcx, JavaThread::exception_pc_offset()), NULL_WORD);
#endif
// Clear the exception oop so GC no longer processes it as a root.
__ movptr(Address(rcx, JavaThread::exception_oop_offset()), NULL_WORD);
__ pop(rcx);
// rax: exception oop
// rcx: exception handler
// rdx: exception pc
__ jmp (rcx);
// -------------
// make sure all code is generated
masm->flush();
_exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize);
}