/*
* This file is part of the Jikes RVM project (http://jikesrvm.org).
*
* This file is licensed to You under the Eclipse Public License (EPL);
* You may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.opensource.org/licenses/eclipse-1.0.php
*
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.
*/
package org.jikesrvm.compilers.opt.runtimesupport.ia32;
import static org.jikesrvm.VM.NOT_REACHED;
import static org.jikesrvm.ia32.RegisterConstants.NONVOLATILE_GPRS;
import static org.jikesrvm.ia32.RegisterConstants.NUM_NONVOLATILE_FPRS;
import static org.jikesrvm.ia32.RegisterConstants.NUM_NONVOLATILE_GPRS;
import static org.jikesrvm.ia32.RegisterConstants.STACK_POINTER;
import static org.jikesrvm.ia32.StackframeLayoutConstants.STACK_SIZE_GUARD;
import static org.jikesrvm.runtime.UnboxedSizeConstants.BYTES_IN_ADDRESS;
import org.jikesrvm.VM;
import org.jikesrvm.architecture.AbstractRegisters;
import org.jikesrvm.compilers.common.CompiledMethod;
import org.jikesrvm.compilers.opt.runtimesupport.OptCompiledMethod;
import org.jikesrvm.ia32.RegisterConstants.GPR;
import org.jikesrvm.runtime.ExceptionDeliverer;
import org.jikesrvm.runtime.Magic;
import org.jikesrvm.scheduler.RVMThread;
import org.vmmagic.pragma.Unpreemptible;
import org.vmmagic.unboxed.Address;
import org.vmmagic.unboxed.Offset;
/**
* Handle exception delivery and stack unwinding for methods
* compiled by optimizing Compiler.
*/
public final class OptExceptionDeliverer extends ExceptionDeliverer {
private static final boolean TRACE = false;
/**
* Pass control to a catch block.
*/
@Override
@Unpreemptible("Deliver exception possibly from unpreemptible code")
public void deliverException(CompiledMethod compiledMethod, Address catchBlockInstructionAddress,
Throwable exceptionObject, AbstractRegisters registers) {
OptCompiledMethod optMethod = (OptCompiledMethod) compiledMethod;
Address fp = registers.getInnermostFramePointer();
RVMThread myThread = RVMThread.getCurrentThread();
if (TRACE) {
VM.sysWrite("Frame size of ");
VM.sysWrite(optMethod.getMethod());
VM.sysWrite(" is ");
VM.sysWrite(optMethod.getFrameFixedSize());
VM.sysWriteln();
}
// reset sp to "empty params" state (ie same as it was after prologue)
Address sp = fp.minus(optMethod.getFrameFixedSize());
registers.getGPRs().set(STACK_POINTER.value(), sp.toWord());
// store exception object for later retrieval by catch block
int offset = optMethod.getUnsignedExceptionOffset();
if (offset != 0) {
// only put the exception object in the stackframe if the catch block is expecting it.
// (if the method hasn't allocated a stack slot for caught exceptions, then we can safely
// drop the exceptionObject on the floor).
Magic.setObjectAtOffset(Magic.addressAsObject(fp), Offset.fromIntSignExtend(-offset), exceptionObject);
if (TRACE) {
VM.sysWrite("Storing exception object ");
VM.sysWrite(Magic.objectAsAddress(exceptionObject));
VM.sysWrite(" at offset ");
VM.sysWrite(offset);
VM.sysWrite(" from framepoint ");
VM.sysWrite(fp);
VM.sysWriteln();
}
}
if (TRACE) {
VM.sysWrite("Registers before delivering exception in ");
VM.sysWrite(optMethod.getMethod());
VM.sysWriteln();
for (GPR reg : GPR.values()) {
VM.sysWrite(reg.toString());
VM.sysWrite(" = ");
VM.sysWrite(registers.getGPRs().get(reg.value()));
VM.sysWriteln();
}
}
// set address at which to resume executing frame
registers.setIP(catchBlockInstructionAddress);
if (TRACE) {
VM.sysWrite("Set ip to ");
VM.sysWrite(registers.getIP());
VM.sysWriteln();
}
VM.enableGC(); // disabled right before RuntimeEntrypoints.deliverException was called
if (VM.VerifyAssertions) VM._assert(registers.getInUse());
registers.setInUse(false);
// 'give back' the portion of the stack we borrowed to run
// exception delivery code when invoked for a hardware trap.
// If this was a straight software trap (athrow) then setting
// the stacklimit should be harmless, since the stacklimit should already have exactly
// the value we are setting it too.
myThread.stackLimit = Magic.objectAsAddress(myThread.getStack()).plus(STACK_SIZE_GUARD);
// "branches" to catchBlockInstructionAddress
Magic.restoreHardwareExceptionState(registers);
if (VM.VerifyAssertions) VM._assert(NOT_REACHED);
}
/**
* Unwind a stackframe.
*/
@Override
@Unpreemptible("Unwind stack possibly from unpreemptible code")
public void unwindStackFrame(CompiledMethod compiledMethod, AbstractRegisters registers) {
Address fp = registers.getInnermostFramePointer();
OptCompiledMethod optMethod = (OptCompiledMethod) compiledMethod;
if (TRACE) {
VM.sysWrite("Registers before unwinding frame for ");
VM.sysWrite(optMethod.getMethod());
VM.sysWriteln();
for (GPR reg : GPR.values()) {
VM.sysWrite(reg.toString());
VM.sysWrite(" = ");
VM.sysWrite(registers.getGPRs().get(reg.value()));
VM.sysWriteln();
}
}
// restore non-volatile registers
int frameOffset = optMethod.getUnsignedNonVolatileOffset();
for (int i = optMethod.getFirstNonVolatileGPR(); i < NUM_NONVOLATILE_GPRS; i++, frameOffset += BYTES_IN_ADDRESS) {
registers.getGPRs().set(NONVOLATILE_GPRS[i].value(), fp.minus(frameOffset).loadWord());
}
if (VM.VerifyAssertions) VM._assert(NUM_NONVOLATILE_FPRS == 0);
registers.unwindStackFrame();
if (TRACE) {
VM.sysWrite("Registers after unwinding frame for ");
VM.sysWrite(optMethod.getMethod());
VM.sysWriteln();
for (GPR reg : GPR.values()) {
VM.sysWrite(reg.toString());
VM.sysWrite(" = ");
VM.sysWrite(registers.getGPRs().get(reg.value()));
VM.sysWriteln();
}
}
}
}