/*

 * Copyright (c) 2001, 2015, 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

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 */

package sun.jvm.hotspot.runtime.x86;

import java.util.*;

import sun.jvm.hotspot.code.*;

import sun.jvm.hotspot.compiler.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

/** Specialization of and implementation of abstract methods of the

    Frame class for the x86 family of CPUs. */

public class X86Frame extends Frame {

  private static final boolean DEBUG;

  static {

    DEBUG = System.getProperty("sun.jvm.hotspot.runtime.x86.X86Frame.DEBUG") != null;

  }

  // All frames

  private static final int LINK_OFFSET                =  0;

  private static final int RETURN_ADDR_OFFSET         =  1;

  private static final int SENDER_SP_OFFSET           =  2;

  // Interpreter frames

  private static final int INTERPRETER_FRAME_MIRROR_OFFSET    =  2; // for native calls only

  private static final int INTERPRETER_FRAME_SENDER_SP_OFFSET = -1;

  private static final int INTERPRETER_FRAME_LAST_SP_OFFSET   = INTERPRETER_FRAME_SENDER_SP_OFFSET - 1;

  private static final int INTERPRETER_FRAME_METHOD_OFFSET    = INTERPRETER_FRAME_LAST_SP_OFFSET - 1;

  private static       int INTERPRETER_FRAME_MDX_OFFSET;         // Non-core builds only

  private static       int INTERPRETER_FRAME_CACHE_OFFSET;

  private static       int INTERPRETER_FRAME_LOCALS_OFFSET;

  private static       int INTERPRETER_FRAME_BCX_OFFSET;

  private static       int INTERPRETER_FRAME_INITIAL_SP_OFFSET;

  private static       int INTERPRETER_FRAME_MONITOR_BLOCK_TOP_OFFSET;

  private static       int INTERPRETER_FRAME_MONITOR_BLOCK_BOTTOM_OFFSET;

  // Entry frames

  private static       int ENTRY_FRAME_CALL_WRAPPER_OFFSET;

  private static VMReg rbp;

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

          initialize(VM.getVM().getTypeDataBase());

        }

      });

  }

  private static synchronized void initialize(TypeDataBase db) {

    INTERPRETER_FRAME_MDX_OFFSET                  = INTERPRETER_FRAME_METHOD_OFFSET - 1;

    INTERPRETER_FRAME_CACHE_OFFSET                = INTERPRETER_FRAME_MDX_OFFSET - 1;

    INTERPRETER_FRAME_LOCALS_OFFSET               = INTERPRETER_FRAME_CACHE_OFFSET - 1;

    INTERPRETER_FRAME_BCX_OFFSET                  = INTERPRETER_FRAME_LOCALS_OFFSET - 1;

    INTERPRETER_FRAME_INITIAL_SP_OFFSET           = INTERPRETER_FRAME_BCX_OFFSET - 1;

    INTERPRETER_FRAME_MONITOR_BLOCK_TOP_OFFSET    = INTERPRETER_FRAME_INITIAL_SP_OFFSET;

    INTERPRETER_FRAME_MONITOR_BLOCK_BOTTOM_OFFSET = INTERPRETER_FRAME_INITIAL_SP_OFFSET;

    ENTRY_FRAME_CALL_WRAPPER_OFFSET = db.lookupIntConstant("frame::entry_frame_call_wrapper_offset");

    if (VM.getVM().getAddressSize() == 4) {

      rbp = new VMReg(5);

    } else {

      rbp = new VMReg(5 << 1);

    }

  }

  // an additional field beyond sp and pc:

  Address raw_fp; // frame pointer

  private Address raw_unextendedSP;

  private X86Frame() {

  }

  private void adjustForDeopt() {

    if ( pc != null) {

      // Look for a deopt pc and if it is deopted convert to original pc

      CodeBlob cb = VM.getVM().getCodeCache().findBlob(pc);

      if (cb != null && cb.isJavaMethod()) {

        NMethod nm = (NMethod) cb;

        if (pc.equals(nm.deoptHandlerBegin())) {

          if (Assert.ASSERTS_ENABLED) {

            Assert.that(this.getUnextendedSP() != null, "null SP in Java frame");

          }

          // adjust pc if frame is deoptimized.

          pc = this.getUnextendedSP().getAddressAt(nm.origPCOffset());

          deoptimized = true;

        }

      }

    }

  }

  public X86Frame(Address raw_sp, Address raw_fp, Address pc) {

    this.raw_sp = raw_sp;

    this.raw_unextendedSP = raw_sp;

    this.raw_fp = raw_fp;

    this.pc = pc;

    adjustUnextendedSP();

    // Frame must be fully constructed before this call

    adjustForDeopt();

    if (DEBUG) {

      System.out.println("X86Frame(sp, fp, pc): " + this);

      dumpStack();

    }

  }

  public X86Frame(Address raw_sp, Address raw_fp) {

    this.raw_sp = raw_sp;

    this.raw_unextendedSP = raw_sp;

    this.raw_fp = raw_fp;

    this.pc = raw_sp.getAddressAt(-1 * VM.getVM().getAddressSize());

    adjustUnextendedSP();

    // Frame must be fully constructed before this call

    adjustForDeopt();

    if (DEBUG) {

      System.out.println("X86Frame(sp, fp): " + this);

      dumpStack();

    }

  }

  public X86Frame(Address raw_sp, Address raw_unextendedSp, Address raw_fp, Address pc) {

    this.raw_sp = raw_sp;

    this.raw_unextendedSP = raw_unextendedSp;

    this.raw_fp = raw_fp;

    this.pc = pc;

    adjustUnextendedSP();

    // Frame must be fully constructed before this call

    adjustForDeopt();

    if (DEBUG) {

      System.out.println("X86Frame(sp, unextendedSP, fp, pc): " + this);

      dumpStack();

    }

  }

  public Object clone() {

    X86Frame frame = new X86Frame();

    frame.raw_sp = raw_sp;

    frame.raw_unextendedSP = raw_unextendedSP;

    frame.raw_fp = raw_fp;

    frame.pc = pc;

    frame.deoptimized = deoptimized;

    return frame;

  }

  public boolean equals(Object arg) {

    if (arg == null) {

      return false;

    }

    if (!(arg instanceof X86Frame)) {

      return false;

    }

    X86Frame other = (X86Frame) arg;

    return (AddressOps.equal(getSP(), other.getSP()) &&

            AddressOps.equal(getUnextendedSP(), other.getUnextendedSP()) &&

            AddressOps.equal(getFP(), other.getFP()) &&

            AddressOps.equal(getPC(), other.getPC()));

  }

  public int hashCode() {

    if (raw_sp == null) {

      return 0;

    }

    return raw_sp.hashCode();

  }

  public String toString() {

    return "sp: " + (getSP() == null? "null" : getSP().toString()) +

         ", unextendedSP: " + (getUnextendedSP() == null? "null" : getUnextendedSP().toString()) +

         ", fp: " + (getFP() == null? "null" : getFP().toString()) +

         ", pc: " + (pc == null? "null" : pc.toString());

  }

  // accessors for the instance variables

  public Address getFP() { return raw_fp; }

  public Address getSP() { return raw_sp; }

  public Address getID() { return raw_sp; }

  // FIXME: not implemented yet (should be done for Solaris/X86)

  public boolean isSignalHandlerFrameDbg() { return false; }

  public int     getSignalNumberDbg()      { return 0;     }

  public String  getSignalNameDbg()        { return null;  }

  public boolean isInterpretedFrameValid() {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(isInterpretedFrame(), "Not an interpreted frame");

    }

    // These are reasonable sanity checks

    if (getFP() == null || getFP().andWithMask(0x3) != null) {

      return false;

    }

    if (getSP() == null || getSP().andWithMask(0x3) != null) {

      return false;

    }

    if (getFP().addOffsetTo(INTERPRETER_FRAME_INITIAL_SP_OFFSET * VM.getVM().getAddressSize()).lessThan(getSP())) {

      return false;

    }

    // These are hacks to keep us out of trouble.

    // The problem with these is that they mask other problems

    if (getFP().lessThanOrEqual(getSP())) {

      // this attempts to deal with unsigned comparison above

      return false;

    }

    if (getFP().minus(getSP()) > 4096 * VM.getVM().getAddressSize()) {

      // stack frames shouldn't be large.

      return false;

    }

    return true;

  }

  // FIXME: not applicable in current system

  //  void    patch_pc(Thread* thread, address pc);

  public Frame sender(RegisterMap regMap, CodeBlob cb) {

    X86RegisterMap map = (X86RegisterMap) regMap;

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(map != null, "map must be set");

    }

    // Default is we done have to follow them. The sender_for_xxx will

    // update it accordingly

    map.setIncludeArgumentOops(false);

    if (isEntryFrame())       return senderForEntryFrame(map);

    if (isInterpretedFrame()) return senderForInterpreterFrame(map);

    if(cb == null) {

      cb = VM.getVM().getCodeCache().findBlob(getPC());

    } else {

      if (Assert.ASSERTS_ENABLED) {

        Assert.that(cb.equals(VM.getVM().getCodeCache().findBlob(getPC())), "Must be the same");

      }

    }

    if (cb != null) {

      return senderForCompiledFrame(map, cb);

    }

    // Must be native-compiled frame, i.e. the marshaling code for native

    // methods that exists in the core system.

    return new X86Frame(getSenderSP(), getLink(), getSenderPC());

  }

  private Frame senderForEntryFrame(X86RegisterMap map) {

    if (DEBUG) {

      System.out.println("senderForEntryFrame");

    }

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(map != null, "map must be set");

    }

    // Java frame called from C; skip all C frames and return top C

    // frame of that chunk as the sender

    X86JavaCallWrapper jcw = (X86JavaCallWrapper) getEntryFrameCallWrapper();

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(!entryFrameIsFirst(), "next Java fp must be non zero");

      Assert.that(jcw.getLastJavaSP().greaterThan(getSP()), "must be above this frame on stack");

    }

    X86Frame fr;

    if (jcw.getLastJavaPC() != null) {

      fr = new X86Frame(jcw.getLastJavaSP(), jcw.getLastJavaFP(), jcw.getLastJavaPC());

    } else {

      fr = new X86Frame(jcw.getLastJavaSP(), jcw.getLastJavaFP());

    }

    map.clear();

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(map.getIncludeArgumentOops(), "should be set by clear");

    }

    return fr;

  }

  //------------------------------------------------------------------------------

  // frame::adjust_unextended_sp

  private void adjustUnextendedSP() {

    CodeBlob cb = cb();

    NMethod senderNm = (cb == null) ? null : cb.asNMethodOrNull();

    if (senderNm != null) {

      }

    }

  }

  private Frame senderForInterpreterFrame(X86RegisterMap map) {

    if (DEBUG) {

      System.out.println("senderForInterpreterFrame");

    }

    Address unextendedSP = addressOfStackSlot(INTERPRETER_FRAME_SENDER_SP_OFFSET).getAddressAt(0);

    Address sp = addressOfStackSlot(SENDER_SP_OFFSET);

    // We do not need to update the callee-save register mapping because above

    // us is either another interpreter frame or a converter-frame, but never

    // directly a compiled frame.

    // 11/24/04 SFG. With the removal of adapter frames this is no longer true.

    // However c2 no longer uses callee save register for java calls so there

    // are no callee register to find.

    if (map.getUpdateMap())

      updateMapWithSavedLink(map, addressOfStackSlot(LINK_OFFSET));

    return new X86Frame(sp, unextendedSP, getLink(), getSenderPC());

  }

  private void updateMapWithSavedLink(RegisterMap map, Address savedFPAddr) {

    map.setLocation(rbp, savedFPAddr);

  }

  private Frame senderForCompiledFrame(X86RegisterMap map, CodeBlob cb) {

    if (DEBUG) {

      System.out.println("senderForCompiledFrame");

    }

    //

    // NOTE: some of this code is (unfortunately) duplicated in X86CurrentFrameGuess

    //

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(map != null, "map must be set");

    }

    // frame owned by optimizing compiler

    if (Assert.ASSERTS_ENABLED) {

        Assert.that(cb.getFrameSize() >= 0, "must have non-zero frame size");

    }

    Address senderSP = getUnextendedSP().addOffsetTo(cb.getFrameSize());

    // On Intel the return_address is always the word on the stack

    Address senderPC = senderSP.getAddressAt(-1 * VM.getVM().getAddressSize());

    // This is the saved value of EBP which may or may not really be an FP.

    // It is only an FP if the sender is an interpreter frame (or C1?).

    Address savedFPAddr = senderSP.addOffsetTo(- SENDER_SP_OFFSET * VM.getVM().getAddressSize());

    if (map.getUpdateMap()) {

      // Tell GC to use argument oopmaps for some runtime stubs that need it.

      // For C1, the runtime stub might not have oop maps, so set this flag

      // outside of update_register_map.

      map.setIncludeArgumentOops(cb.callerMustGCArguments());

      if (cb.getOopMaps() != null) {

        OopMapSet.updateRegisterMap(this, cb, map, true);

      }

      // Since the prolog does the save and restore of EBP there is no oopmap

      // for it so we must fill in its location as if there was an oopmap entry

      // since if our caller was compiled code there could be live jvm state in it.

      updateMapWithSavedLink(map, savedFPAddr);

    }

    return new X86Frame(senderSP, savedFPAddr.getAddressAt(0), senderPC);

  }

  protected boolean hasSenderPD() {

    // FIXME

    // Check for null ebp? Need to do some tests.

    return true;

  }

  public long frameSize() {

    return (getSenderSP().minus(getSP()) / VM.getVM().getAddressSize());

  }

  public Address getLink() {

    return addressOfStackSlot(LINK_OFFSET).getAddressAt(0);

  }

  public Address getUnextendedSP() { return raw_unextendedSP; }

  // Return address:

  public Address getSenderPCAddr() { return addressOfStackSlot(RETURN_ADDR_OFFSET); }

  public Address getSenderPC()     { return getSenderPCAddr().getAddressAt(0);      }

  public Address getSenderSP()     { return addressOfStackSlot(SENDER_SP_OFFSET); }

  public Address addressOfInterpreterFrameLocals() {

    return addressOfStackSlot(INTERPRETER_FRAME_LOCALS_OFFSET);

  }

  private Address addressOfInterpreterFrameBCX() {

    return addressOfStackSlot(INTERPRETER_FRAME_BCX_OFFSET);

  }

  public int getInterpreterFrameBCI() {

    // FIXME: this is not atomic with respect to GC and is unsuitable

    // for use in a non-debugging, or reflective, system. Need to

    // figure out how to express this.

    Address bcp = addressOfInterpreterFrameBCX().getAddressAt(0);

    Address methodHandle = addressOfInterpreterFrameMethod().getAddressAt(0);

    Method method = (Method)Metadata.instantiateWrapperFor(methodHandle);

    return bcpToBci(bcp, method);

  }

  public Address addressOfInterpreterFrameMDX() {

    return addressOfStackSlot(INTERPRETER_FRAME_MDX_OFFSET);

  }

  // FIXME

  //inline int frame::interpreter_frame_monitor_size() {

  //  return BasicObjectLock::size();

  //}

  // expression stack

  // (the max_stack arguments are used by the GC; see class FrameClosure)

  public Address addressOfInterpreterFrameExpressionStack() {

    Address monitorEnd = interpreterFrameMonitorEnd().address();

    return monitorEnd.addOffsetTo(-1 * VM.getVM().getAddressSize());

  }

  public int getInterpreterFrameExpressionStackDirection() { return -1; }

  // top of expression stack

  public Address addressOfInterpreterFrameTOS() {

    return getSP();

  }

  /** Expression stack from top down */

  public Address addressOfInterpreterFrameTOSAt(int slot) {

    return addressOfInterpreterFrameTOS().addOffsetTo(slot * VM.getVM().getAddressSize());

  }

  public Address getInterpreterFrameSenderSP() {

    if (Assert.ASSERTS_ENABLED) {

      Assert.that(isInterpretedFrame(), "interpreted frame expected");

    }

    return addressOfStackSlot(INTERPRETER_FRAME_SENDER_SP_OFFSET).getAddressAt(0);

  }

  // Monitors

  public BasicObjectLock interpreterFrameMonitorBegin() {

    return new BasicObjectLock(addressOfStackSlot(INTERPRETER_FRAME_MONITOR_BLOCK_BOTTOM_OFFSET));

  }

  public BasicObjectLock interpreterFrameMonitorEnd() {

    Address result = addressOfStackSlot(INTERPRETER_FRAME_MONITOR_BLOCK_TOP_OFFSET).getAddressAt(0);

    if (Assert.ASSERTS_ENABLED) {

      // make sure the pointer points inside the frame

      Assert.that(AddressOps.gt(getFP(), result), "result must <  than frame pointer");

      Assert.that(AddressOps.lte(getSP(), result), "result must >= than stack pointer");

    }

    return new BasicObjectLock(result);

  }

  public int interpreterFrameMonitorSize() {

    return BasicObjectLock.size();

  }

  // Method

  public Address addressOfInterpreterFrameMethod() {

    return addressOfStackSlot(INTERPRETER_FRAME_METHOD_OFFSET);

  }

  // Constant pool cache

  public Address addressOfInterpreterFrameCPCache() {

    return addressOfStackSlot(INTERPRETER_FRAME_CACHE_OFFSET);

  }

  // Entry frames

  public JavaCallWrapper getEntryFrameCallWrapper() {

    return new X86JavaCallWrapper(addressOfStackSlot(ENTRY_FRAME_CALL_WRAPPER_OFFSET).getAddressAt(0));

  }

  protected Address addressOfSavedOopResult() {

    // offset is 2 for compiler2 and 3 for compiler1

    return getSP().addOffsetTo((VM.getVM().isClientCompiler() ? 2 : 3) *

                               VM.getVM().getAddressSize());

  }

  protected Address addressOfSavedReceiver() {

    return getSP().addOffsetTo(-4 * VM.getVM().getAddressSize());

  }