/*
 * Copyright (c) 2014, 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.
 *
 */

package sun.jvm.hotspot.debugger.proc;

import java.io.*;
import java.net.*;
import java.util.*;
import java.lang.reflect.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.debugger.cdbg.*;
import sun.jvm.hotspot.debugger.proc.amd64.*;
import sun.jvm.hotspot.debugger.proc.aarch64.*;
import sun.jvm.hotspot.debugger.proc.sparc.*;
import sun.jvm.hotspot.debugger.proc.ppc64.*;
import sun.jvm.hotspot.debugger.proc.x86.*;
import sun.jvm.hotspot.debugger.ppc64.*;
import sun.jvm.hotspot.debugger.amd64.*;
import sun.jvm.hotspot.debugger.aarch64.*;
import sun.jvm.hotspot.debugger.sparc.*;
import sun.jvm.hotspot.debugger.x86.*;
import sun.jvm.hotspot.utilities.*;

 An implementation of the JVMDebugger interface which sits on
top of proc and relies on the SA's proc import module for
communication with the debugger. 
 NOTE that since we have the notion of fetching "Java
primitive types" from the remote process (which might have
different sizes than we expect) we have a bootstrapping
problem. We need to know the sizes of these types before we can
fetch them. The current implementation solves this problem by
requiring that it be configured with these type sizes before they
can be fetched. The readJ(Type) routines here will throw a
RuntimeException if they are called before the debugger is
configured with the Java primitive type sizes. 
/** <P> An implementation of the JVMDebugger interface which sits on
 * top of proc and relies on the SA's proc import module for
 * communication with the debugger. </P>
 *
 * <P> <B>NOTE</B> that since we have the notion of fetching "Java
 * primitive types" from the remote process (which might have
 * different sizes than we expect) we have a bootstrapping
 * problem. We need to know the sizes of these types before we can
 * fetch them. The current implementation solves this problem by
 * requiring that it be configured with these type sizes before they
 * can be fetched. The readJ(Type) routines here will throw a
 * RuntimeException if they are called before the debugger is
 * configured with the Java primitive type sizes. </P>
 */

public class ProcDebuggerLocal extends DebuggerBase implements ProcDebugger {
    protected static final int cacheSize = 16 * 1024 * 1024; // 16 MB

    //------------------------------------------------------------------------
    // Implementation of Debugger interface
    //

    
 machDesc may be null if it couldn't be determined yet; i.e.,
if we're on SPARC, we need to ask the remote process whether
we're in 32- or 64-bit mode. 
 useCache should be set to true if debugging is being done
locally, and to false if the debugger is being created for the
purpose of supporting remote debugging. 
 /** <P> machDesc may be null if it couldn't be determined yet; i.e.,
     * if we're on SPARC, we need to ask the remote process whether
     * we're in 32- or 64-bit mode. </P>
     *
     * <P> useCache should be set to true if debugging is being done
     * locally, and to false if the debugger is being created for the
     * purpose of supporting remote debugging. </P> */
    public ProcDebuggerLocal(MachineDescription machDesc, boolean useCache) {
        this.machDesc = machDesc;
        int cacheNumPages;
        int cachePageSize;

        final String cpu = PlatformInfo.getCPU();
        if (cpu.equals("sparc")) {
            threadFactory = new ProcSPARCThreadFactory(this);
            pcRegIndex = SPARCThreadContext.R_PC;
            fpRegIndex = SPARCThreadContext.R_I6;
        } else if (cpu.equals("x86")) {
            threadFactory = new ProcX86ThreadFactory(this);
            pcRegIndex = X86ThreadContext.EIP;
            fpRegIndex = X86ThreadContext.EBP;
            unalignedAccessesOkay = true;
        } else if (cpu.equals("amd64") || cpu.equals("x86_64")) {
            threadFactory = new ProcAMD64ThreadFactory(this);
            pcRegIndex = AMD64ThreadContext.RIP;
            fpRegIndex = AMD64ThreadContext.RBP;
        } else if (cpu.equals("aarch64")) {
            threadFactory = new ProcAARCH64ThreadFactory(this);
            pcRegIndex = AARCH64ThreadContext.PC;
            fpRegIndex = AARCH64ThreadContext.FP;
        } else if (cpu.equals("ppc64")) {
            threadFactory = new ProcPPC64ThreadFactory(this);
            pcRegIndex = PPC64ThreadContext.PC;
            fpRegIndex = PPC64ThreadContext.SP;
        } else {
          try {
            Class tfc = Class.forName("sun.jvm.hotspot.debugger.proc." +
               cpu.toLowerCase() + ".Proc" + cpu.toUpperCase() +
               "ThreadFactory");
            Constructor[] ctfc = tfc.getConstructors();
            threadFactory = (ProcThreadFactory)ctfc[0].newInstance(this);
          } catch (Exception e) {
            throw new RuntimeException("Thread access for CPU architecture " + PlatformInfo.getCPU() + " not yet supported");
            // Note: pcRegIndex and fpRegIndex do not appear to be referenced
          }
        }
        if (useCache) {
            // Cache portion of the remote process's address space.
            // For now, this cache works best if it covers the entire
            // heap of the remote process. FIXME: at least should make this
            // tunable from the outside, i.e., via the UI. This is a 16 MB
            // cache divided on SPARC into 2048 8K pages and on x86 into
            // 4096 4K pages; the page size must be adjusted to be the OS's
            // page size.

            cachePageSize = getPageSize();
            cacheNumPages = parseCacheNumPagesProperty(cacheSize / cachePageSize);
            initCache(cachePageSize, cacheNumPages);
        }

        resetNativePointers();
        clearCacheFields();
    }

    
FIXME: implement this with a Runtime.exec() of ps followed by
parsing of its output /** FIXME: implement this with a Runtime.exec() of ps followed by
     * parsing of its output */
    public boolean hasProcessList() throws DebuggerException {
        return false;
    }

    public List getProcessList() throws DebuggerException {
        throw new DebuggerException("Not yet supported");
    }


    
From the Debugger interface via JVMDebugger /** From the Debugger interface via JVMDebugger */
    public synchronized void attach(int processID) throws DebuggerException {
        checkAttached();
        isCore = false;
        attach0(new Integer(processID).toString());
        attached = true;
        suspended = true;
    }

    
From the Debugger interface via JVMDebugger /** From the Debugger interface via JVMDebugger */
    public synchronized void attach
    (String executableName, String coreFileName) throws DebuggerException {
        checkAttached();
        isCore = true;
        topFrameCache = new HashMap();
        attach0(executableName, coreFileName);
        attached = true;
        suspended = true;
    }

    
From the Debugger interface via JVMDebugger /** From the Debugger interface via JVMDebugger */
    public synchronized boolean detach() {
        if (! attached) {
            return false;
        }

        try {
            if (p_ps_prochandle == 0L) {
                return false;
            }
            detach0();
            clearCache();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        } finally {
            resetNativePointers();
            clearCacheFields();
            suspended = false;
            attached = false;
        }
    }

    public synchronized void suspend() throws DebuggerException {
        requireAttach();
        if (suspended) {
            throw new DebuggerException("Process already suspended");
        }
        suspend0();
        suspended = true;
        enableCache();
        reresolveLoadObjects();
    }

    public synchronized void resume() throws DebuggerException {
        requireAttach();
        if (!suspended) {
            throw new DebuggerException("Process not suspended");
        }
        resume0();
        disableCache();
        suspended = false;
    }

    public synchronized boolean isSuspended() throws DebuggerException {
        requireAttach();
        return suspended;
    }

    
From the Debugger interface via JVMDebugger /** From the Debugger interface via JVMDebugger */
    public Address parseAddress(String addressString) throws NumberFormatException {
        long addr = utils.scanAddress(addressString);
        if (addr == 0) {
            return null;
        }
        return new ProcAddress(this, addr);
    }

    
From the Debugger interface via JVMDebugger /** From the Debugger interface via JVMDebugger */
    public String getOS() {
        return PlatformInfo.getOS();
    }

    
From the Debugger interface via JVMDebugger /** From the Debugger interface via JVMDebugger */
    public String getCPU() {
        return PlatformInfo.getCPU();
    }

    public boolean hasConsole() throws DebuggerException {
        return false;
    }

    public String consoleExecuteCommand(String cmd) throws DebuggerException {
        throw new DebuggerException("Can't execute console commands");
    }

    public String getConsolePrompt() throws DebuggerException {
        return "";
    }

    public CDebugger getCDebugger() throws DebuggerException {
        if (cdbg == null) {
            cdbg = new ProcCDebugger(this);
        }
        return cdbg;
    }

    
From the SymbolLookup interface via Debugger and JVMDebugger /** From the SymbolLookup interface via Debugger and JVMDebugger */
    public synchronized Address lookup(String objectName, String symbol) {
        requireAttach();
        long addr = lookupByName0(objectName, symbol);
        if (addr == 0) {
            return null;
        }
        return new ProcAddress(this, addr);
    }

    
From the SymbolLookup interface via Debugger and JVMDebugger /** From the SymbolLookup interface via Debugger and JVMDebugger */
    public synchronized OopHandle lookupOop(String objectName, String symbol) {
        Address addr = lookup(objectName, symbol);
        if (addr == null) {
            return null;
        }
        return addr.addOffsetToAsOopHandle(0);
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public MachineDescription getMachineDescription() {
        return machDesc;
    }

    
Internal routine supporting lazy setting of MachineDescription,
since on SPARC we will need to query the remote process to ask
it what its data model is (32- or 64-bit).
/** Internal routine supporting lazy setting of MachineDescription,
     * since on SPARC we will need to query the remote process to ask
     * it what its data model is (32- or 64-bit).
     */

    public void setMachineDescription(MachineDescription machDesc) {
        this.machDesc = machDesc;
        setBigEndian(machDesc.isBigEndian());
        utils = new DebuggerUtilities(machDesc.getAddressSize(), machDesc.isBigEndian());
    }

    public synchronized int getRemoteProcessAddressSize()
    throws DebuggerException {
        requireAttach();
        return getRemoteProcessAddressSize0();
    }

    //--------------------------------------------------------------------------------
    // Implementation of ThreadAccess interface
    //

    
From the ThreadAccess interface via Debugger and JVMDebugger /** From the ThreadAccess interface via Debugger and JVMDebugger */
    public ThreadProxy getThreadForIdentifierAddress(Address addr) {
        return threadFactory.createThreadWrapper(addr);
    }

    public ThreadProxy getThreadForThreadId(long id) {
        return threadFactory.createThreadWrapper(id);
    }

    //----------------------------------------------------------------------
    // Overridden from DebuggerBase because we need to relax alignment
    // constraints on x86

    public long readJLong(long address)
    throws UnmappedAddressException, UnalignedAddressException {
        checkJavaConfigured();
        // FIXME: allow this to be configurable. Undesirable to add a
        // dependency on the runtime package here, though, since this
        // package should be strictly underneath it.
        if (unalignedAccessesOkay) {
            utils.checkAlignment(address, jintSize);
        } else {
            utils.checkAlignment(address, jlongSize);
        }
        byte[] data = readBytes(address, jlongSize);
        return utils.dataToJLong(data, jlongSize);
    }

    //--------------------------------------------------------------------------------
    // Internal routines (for implementation of ProcAddress).
    // These must not be called until the MachineDescription has been set up.
    //

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public String addressValueToString(long address) {
        return utils.addressValueToString(address);
    }

    
Need to override this to relax alignment checks on Solaris/x86. /** Need to override this to relax alignment checks on Solaris/x86. */
    public long readCInteger(long address, long numBytes, boolean isUnsigned)
    throws UnmappedAddressException, UnalignedAddressException {
        checkConfigured();
        if (!unalignedAccessesOkay) {
            utils.checkAlignment(address, numBytes);
        } else {
            // Only slightly relaxed semantics -- this is a hack, but is
            // necessary on Solaris/x86 where it seems the compiler is
            // putting some global 64-bit data on 32-bit boundaries
            if (numBytes == 8) {
                utils.checkAlignment(address, 4);
            } else {
                utils.checkAlignment(address, numBytes);
            }
        }
        byte[] data = readBytes(address, numBytes);
        return utils.dataToCInteger(data, isUnsigned);
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public ProcAddress readAddress(long address)
    throws UnmappedAddressException, UnalignedAddressException {
        long value = readAddressValue(address);
        return (value == 0 ? null : new ProcAddress(this, value));
    }

    public ProcAddress readCompOopAddress(long address)
    throws UnmappedAddressException, UnalignedAddressException {
        long value = readCompOopAddressValue(address);
        return (value == 0 ? null : new ProcAddress(this, value));
    }

    public ProcAddress readCompKlassAddress(long address)
    throws UnmappedAddressException, UnalignedAddressException {
        long value = readCompKlassAddressValue(address);
        return (value == 0 ? null : new ProcAddress(this, value));
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public ProcOopHandle readOopHandle(long address)
    throws UnmappedAddressException, UnalignedAddressException, NotInHeapException {
        long   value = readAddressValue(address);
        return (value == 0 ? null : new ProcOopHandle(this, value));
    }

    public ProcOopHandle readCompOopHandle(long address) {
        long value = readCompOopAddressValue(address);
        return (value == 0 ? null : new ProcOopHandle(this, value));
    }

    public void writeBytesToProcess(long address, long numBytes, byte[] data)
    throws UnmappedAddressException, DebuggerException {
        if (isCore) {
            throw new DebuggerException("Attached to a core file!");
        }
        writeBytesToProcess0(address, numBytes, data);
    }

    public synchronized ReadResult readBytesFromProcess(long address, long numBytes)
    throws DebuggerException {
        requireAttach();
        byte[] res = readBytesFromProcess0(address, numBytes);
        if(res != null)
            return new ReadResult(res);
        else
            return new ReadResult(address);
    }

    protected int getPageSize() {
        int pagesize = getPageSize0();
        if (pagesize == -1) {
            // return the hard coded default value.
            if (PlatformInfo.getCPU().equals("sparc") ||
                PlatformInfo.getCPU().equals("amd64") )
               pagesize = 8196;
            else
               pagesize = 4096;
        }
        return pagesize;
    }

    //--------------------------------------------------------------------------------
    // Thread context access. Can not be package private, but should
    // only be accessed by the architecture-specific subpackages.

    
From the ProcDebugger interface. May have to redefine this later. /** From the ProcDebugger interface. May have to redefine this later. */
    public synchronized long[] getThreadIntegerRegisterSet(int tid) {
        requireAttach();
        return getThreadIntegerRegisterSet0(tid);
    }

    //--------------------------------------------------------------------------------
    // Address access. Can not be package private, but should only be
    // accessed by the architecture-specific subpackages.

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public long getAddressValue(Address addr) {
        if (addr == null) return 0;
        return ((ProcAddress) addr).getValue();
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public Address newAddress(long value) {
        if (value == 0) return null;
        return new ProcAddress(this, value);
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public synchronized List getThreadList() throws DebuggerException {
        requireAttach();
        List res = null;
        if (isCore && (threadListCache != null)) {
            res = threadListCache;
        } else {
            res = new ArrayList();
            fillThreadList0(res);
            if (isCore) {
                threadListCache = res;
            }
        }
        return res;
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public synchronized List getLoadObjectList() throws DebuggerException {
        requireAttach();
        if (!suspended) {
            throw new DebuggerException("Process not suspended");
        }

        if (loadObjectCache == null) {
            updateLoadObjectCache();
        }
        return loadObjectCache;
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public synchronized CFrame topFrameForThread(ThreadProxy thread)
    throws DebuggerException {
        requireAttach();
        CFrame res = null;
        if (isCore && ((res = (CFrame) topFrameCache.get(thread)) != null)) {
            return res;
        } else {
            ThreadContext context = thread.getContext();
            int numRegs = context.getNumRegisters();
            long[] regs = new long[numRegs];
            for (int i = 0; i < numRegs; i++) {
                regs[i] = context.getRegister(i);
            }
            res = fillCFrameList0(regs);
            if (isCore) {
                topFrameCache.put(thread, res);
            }
            return res;
        }
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public synchronized ClosestSymbol lookup(long address) {
        requireAttach();
        return lookupByAddress0(address);
    }

    
From the ProcDebugger interface /** From the ProcDebugger interface */
    public String demangle(String name) {
        return demangle0(name);
    }

    //------------- Internals only below this point --------------------
    //
    //

    private void updateLoadObjectCache() {
        List res = new ArrayList();
        nameToDsoMap = new HashMap();
        fillLoadObjectList0(res);
        loadObjectCache = sortLoadObjects(res);
    }

    // sort load objects by base address
    private static List sortLoadObjects(List in) {
        // sort the list by base address
        Object[] arr = in.toArray();
        Arrays.sort(arr, loadObjectComparator);
        return Arrays.asList(arr);
    }

    private long lookupByName(String objectName, String symbolName)
    throws DebuggerException {
        // NOTE: this assumes that process is suspended (which is probably
        // necessary assumption given that DSOs can be loaded/unloaded as
        // process runs). Should update documentation.
        if (nameToDsoMap == null) {
            getLoadObjectList();
        }
        SharedObject dso = (SharedObject) nameToDsoMap.get(objectName);
        // The DSO can be null because we use this to search through known
        // DSOs in HotSpotTypeDataBase (for example)
        if (dso != null) {
            ProcAddress addr = (ProcAddress) dso.lookupSymbol(symbolName);
            if (addr != null) {
                return addr.getValue();
            }
        }
        return 0;
    }

    private SharedObject findDSOByName(String fullPathName) {
        if (loadObjectCache == null)
            return null;
        for (Iterator iter = loadObjectCache.iterator(); iter.hasNext(); ) {
            SharedObject dso = (SharedObject) iter.next();
            if (dso.getName().equals(fullPathName)) {
                return dso;
            }
        }
        return null;
    }

    private void reresolveLoadObjects() throws DebuggerException {
        if (loadObjectCache == null) {
            return;
        }
        updateLoadObjectCache();
    }


    private void checkAttached() {
        if (attached) {
            if (isCore) {
                throw new DebuggerException("already attached to a core file!");
            } else {
                throw new DebuggerException("already attached to a process!");
            }
        }
    }

    private void requireAttach() {
        if (! attached) {
            throw new RuntimeException("not attached to a process or core file!");
        }
    }

    private void clearCacheFields() {
        loadObjectCache = null;
        nameToDsoMap    = null;
        threadListCache = null;
        topFrameCache   = null;
    }

    private void resetNativePointers() {
        p_ps_prochandle          = 0L;

        // reset thread_db pointers
        libthread_db_handle    = 0L;
        p_td_thragent_t        = 0L;
        p_td_init              = 0L;
        p_td_ta_new            = 0L;
        p_td_ta_delete         = 0L;
        p_td_ta_thr_iter       = 0L;
        p_td_thr_get_info      = 0L;
        p_td_ta_map_id2thr     = 0L;
        p_td_thr_getgregs      = 0L;

        // part of class sharing workaround
        classes_jsa_fd         = -1;
        p_file_map_header      = 0L;
    }

    // native methods and native helpers

    // attach, detach
    private native void attach0(String pid) throws DebuggerException;
    private native void attach0(String executableFile, String coreFileName) throws DebuggerException;
    private native void detach0() throws DebuggerException;

    // address size, page size
    private native int getRemoteProcessAddressSize0() throws DebuggerException;
    private native int getPageSize0() throws DebuggerException;

    // threads, stacks
    private native long[] getThreadIntegerRegisterSet0(long tid) throws DebuggerException;
    private native void   fillThreadList0(List l) throws DebuggerException;

    // fills stack frame list given reg set of the top frame and top frame
    private native ProcCFrame fillCFrameList0(long[] regs) throws DebuggerException;

    // helper called by fillCFrameList0
    private ProcCFrame createSenderFrame(ProcCFrame f, long pc, long fp) {
        ProcCFrame sender = new ProcCFrame(this, newAddress(pc), newAddress(fp));
        if (f != null) {
            f.setSender(sender);
        }
        return sender;
    }

    // shared objects
    private native void fillLoadObjectList0(List l) throws DebuggerException;

    // helper called by fillLoadObjectList0
    private LoadObject createLoadObject(String fileName, long textsize, long base) {
        File f = new File(fileName);
        Address baseAddr = newAddress(base);
        SharedObject res = findDSOByName(fileName);
        if (res != null) {
            // already in cache. just change the base, if needed
            Address oldBase = res.getBase();
            if (! baseAddr.equals(oldBase)) {
                res.setBase(baseAddr);
            }
        } else {
            // new shared object.
            res = new SharedObject(this, fileName, f.length(), baseAddr);
        }
        nameToDsoMap.put(f.getName(), res);
        return res;
    }

    // symbol-to-pc
    private native long lookupByName0(String objectName, String symbolName) throws DebuggerException;
    private native ClosestSymbol lookupByAddress0(long address) throws DebuggerException;

    // helper called by lookupByAddress0
    private ClosestSymbol createClosestSymbol(String name, long offset) {
        return new ClosestSymbol(name, offset);
    }

    // process read/write
    private native byte[] readBytesFromProcess0(long address, long numBytes) throws DebuggerException;
    private native void writeBytesToProcess0(long address, long numBytes, byte[] data) throws DebuggerException;

    // process control
    private native void suspend0() throws DebuggerException;
    private native void resume0() throws DebuggerException;

    // demangle a C++ name
    private native String demangle0(String name);

    // init JNI ids to fields, methods
    private native static void initIDs() throws DebuggerException;
    private static LoadObjectComparator loadObjectComparator;

    static {
        System.loadLibrary("saproc");
        initIDs();
        loadObjectComparator = new LoadObjectComparator();
    }

    private boolean unalignedAccessesOkay;
    private ProcThreadFactory threadFactory;

    // indices of PC and FP registers in gregset
    private int pcRegIndex;
    private int fpRegIndex;

    // Symbol lookup support
    // This is a map of library names to DSOs
    private Map nameToDsoMap;  // Map<String, SharedObject>

    // C/C++ debugging support
    private List/*<LoadObject>*/ loadObjects;
    private CDebugger cdbg;

    // ProcessControl support
    private boolean suspended;

    // libproc handle
    private long p_ps_prochandle;

    // libthread.so's dlopen handle, thread agent
    // and function pointers
    private long libthread_db_handle;
    private long p_td_thragent_t;
    private long p_td_init;
    private long p_td_ta_new;
    private long p_td_ta_delete;
    private long p_td_ta_thr_iter;
    private long p_td_thr_get_info;
    private long p_td_ta_map_id2thr;
    private long p_td_thr_getgregs;

    // part of class sharing workaround
    private int classes_jsa_fd;
    private long p_file_map_header;

    private boolean attached = false;
    private boolean isCore;

    // for core files, we cache load object list, thread list, top frames etc.
    // for processes we cache load object list and sync. it during suspend.
    private List threadListCache;
    private List loadObjectCache;
    private Map  topFrameCache;      // Map<ThreadProxy, CFrame>
}