jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java@71f35e4b93a5 (annotated)

src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java@71f35e4b93a5 (annotated)

src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java

Wed, 23 Jan 2013 13:27:24 -0800

author: jjg
date: Wed, 23 Jan 2013 13:27:24 -0800
changeset 1521: 71f35e4b93a5
parent 1473: 31780dd06ec7
child 1541: 4cc73ec94686
permissions: -rw-r--r--

8006775: JSR 308: Compiler changes in JDK8
Reviewed-by: jjg
Contributed-by: mernst@cs.washington.edu, wmdietl@cs.washington.edu, mpapi@csail.mit.edu, mahmood@notnoop.com

 /*
  * Copyright (c) 1999, 2013, 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.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * 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 com.sun.tools.javac.jvm;
 import java.io.*;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
 import java.util.HashSet;
 import javax.lang.model.type.TypeKind;
 import javax.tools.JavaFileManager;
 import javax.tools.FileObject;
 import javax.tools.JavaFileObject;
 import com.sun.tools.javac.code.*;
 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
 import com.sun.tools.javac.code.Attribute.TypeCompound;
 import com.sun.tools.javac.code.Symbol.*;
 import com.sun.tools.javac.code.Type.*;
 import com.sun.tools.javac.code.Types.UniqueType;
 import com.sun.tools.javac.file.BaseFileObject;
 import com.sun.tools.javac.jvm.Pool.DynamicMethod;
 import com.sun.tools.javac.jvm.Pool.Method;
 import com.sun.tools.javac.jvm.Pool.MethodHandle;
 import com.sun.tools.javac.jvm.Pool.Variable;
 import com.sun.tools.javac.util.*;
 import static com.sun.tools.javac.code.Flags.*;
 import static com.sun.tools.javac.code.Kinds.*;
 import static com.sun.tools.javac.code.TypeTag.*;
 import static com.sun.tools.javac.jvm.UninitializedType.*;
 import static com.sun.tools.javac.main.Option.*;
 import static javax.tools.StandardLocation.CLASS_OUTPUT;
 /** This class provides operations to map an internal symbol table graph
  *  rooted in a ClassSymbol into a classfile.
  *
  *  <p><b>This is NOT part of any supported API.
  *  If you write code that depends on this, you do so at your own risk.
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
 public class ClassWriter extends ClassFile {
     protected static final Context.Key<ClassWriter> classWriterKey =
         new Context.Key<ClassWriter>();
     private final Options options;
     /** Switch: verbose output.
      */
     private boolean verbose;
     /** Switch: scramble private field names.
      */
     private boolean scramble;
     /** Switch: scramble all field names.
      */
     private boolean scrambleAll;
     /** Switch: retrofit mode.
      */
     private boolean retrofit;
     /** Switch: emit source file attribute.
      */
     private boolean emitSourceFile;
     /** Switch: generate CharacterRangeTable attribute.
      */
     private boolean genCrt;
     /** Switch: describe the generated stackmap.
      */
     boolean debugstackmap;
     /**
      * Target class version.
      */
     private Target target;
     /**
      * Source language version.
      */
     private Source source;
     /** Type utilities. */
     private Types types;
     /** The initial sizes of the data and constant pool buffers.
      *  Sizes are increased when buffers get full.
      */
     static final int DATA_BUF_SIZE = 0x0fff0;
     static final int POOL_BUF_SIZE = 0x1fff0;
     /** An output buffer for member info.
      */
     ByteBuffer databuf = new ByteBuffer(DATA_BUF_SIZE);
     /** An output buffer for the constant pool.
      */
     ByteBuffer poolbuf = new ByteBuffer(POOL_BUF_SIZE);
     /** An output buffer for type signatures.
      */
     ByteBuffer sigbuf = new ByteBuffer();
     /** The constant pool.
      */
     Pool pool;
     /** The inner classes to be written, as a set.
      */
     Set<ClassSymbol> innerClasses;
     /** The inner classes to be written, as a queue where
      *  enclosing classes come first.
      */
     ListBuffer<ClassSymbol> innerClassesQueue;
     /** The bootstrap methods to be written in the corresponding class attribute
      *  (one for each invokedynamic)
      */
     Map<DynamicMethod, MethodHandle> bootstrapMethods;
     /** The log to use for verbose output.
      */
     private final Log log;
     /** The name table. */
     private final Names names;
     /** Access to files. */
     private final JavaFileManager fileManager;
     /** The tags and constants used in compressed stackmap. */
     static final int SAME_FRAME_SIZE = 64;
     static final int SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247;
     static final int SAME_FRAME_EXTENDED = 251;
     static final int FULL_FRAME = 255;
     static final int MAX_LOCAL_LENGTH_DIFF = 4;
     /** Get the ClassWriter instance for this context. */
     public static ClassWriter instance(Context context) {
         ClassWriter instance = context.get(classWriterKey);
         if (instance == null)
             instance = new ClassWriter(context);
         return instance;
     }
     /** Construct a class writer, given an options table.
      */
     protected ClassWriter(Context context) {
         context.put(classWriterKey, this);
         log = Log.instance(context);
         names = Names.instance(context);
         options = Options.instance(context);
         target = Target.instance(context);
         source = Source.instance(context);
         types = Types.instance(context);
         fileManager = context.get(JavaFileManager.class);
         verbose        = options.isSet(VERBOSE);
         scramble       = options.isSet("-scramble");
         scrambleAll    = options.isSet("-scrambleAll");
         retrofit       = options.isSet("-retrofit");
         genCrt         = options.isSet(XJCOV);
         debugstackmap  = options.isSet("debugstackmap");
         emitSourceFile = options.isUnset(G_CUSTOM) ||
                             options.isSet(G_CUSTOM, "source");
         String dumpModFlags = options.get("dumpmodifiers");
         dumpClassModifiers =
             (dumpModFlags != null && dumpModFlags.indexOf('c') != -1);
         dumpFieldModifiers =
             (dumpModFlags != null && dumpModFlags.indexOf('f') != -1);
         dumpInnerClassModifiers =
             (dumpModFlags != null && dumpModFlags.indexOf('i') != -1);
         dumpMethodModifiers =
             (dumpModFlags != null && dumpModFlags.indexOf('m') != -1);
     }
 /******************************************************************
  * Diagnostics: dump generated class names and modifiers
  ******************************************************************/
     /** Value of option 'dumpmodifiers' is a string
      *  indicating which modifiers should be dumped for debugging:
      *    'c' -- classes
      *    'f' -- fields
      *    'i' -- innerclass attributes
      *    'm' -- methods
      *  For example, to dump everything:
      *    javac -XDdumpmodifiers=cifm MyProg.java
      */
     private final boolean dumpClassModifiers; // -XDdumpmodifiers=c
     private final boolean dumpFieldModifiers; // -XDdumpmodifiers=f
     private final boolean dumpInnerClassModifiers; // -XDdumpmodifiers=i
     private final boolean dumpMethodModifiers; // -XDdumpmodifiers=m
     /** Return flags as a string, separated by " ".
      */
     public static String flagNames(long flags) {
         StringBuilder sbuf = new StringBuilder();
         int i = 0;
         long f = flags & StandardFlags;
         while (f != 0) {
             if ((f & 1) != 0) {
                 sbuf.append(" ");
                 sbuf.append(flagName[i]);
             }
             f = f >> 1;
             i++;
         }
         return sbuf.toString();
     }
     //where
         private final static String[] flagName = {
             "PUBLIC", "PRIVATE", "PROTECTED", "STATIC", "FINAL",
             "SUPER", "VOLATILE", "TRANSIENT", "NATIVE", "INTERFACE",
             "ABSTRACT", "STRICTFP"};
 /******************************************************************
  * Output routines
  ******************************************************************/
     /** Write a character into given byte buffer;
      *  byte buffer will not be grown.
      */
     void putChar(ByteBuffer buf, int op, int x) {
         buf.elems[op  ] = (byte)((x >>  8) & 0xFF);
         buf.elems[op+1] = (byte)((x      ) & 0xFF);
     }
     /** Write an integer into given byte buffer;
      *  byte buffer will not be grown.
      */
     void putInt(ByteBuffer buf, int adr, int x) {
         buf.elems[adr  ] = (byte)((x >> 24) & 0xFF);
         buf.elems[adr+1] = (byte)((x >> 16) & 0xFF);
         buf.elems[adr+2] = (byte)((x >>  8) & 0xFF);
         buf.elems[adr+3] = (byte)((x      ) & 0xFF);
     }
 /******************************************************************
  * Signature Generation
  ******************************************************************/
     /** Assemble signature of given type in string buffer.
      */
     void assembleSig(Type type) {
         type = type.unannotatedType();
         switch (type.getTag()) {
         case BYTE:
             sigbuf.appendByte('B');
             break;
         case SHORT:
             sigbuf.appendByte('S');
             break;
         case CHAR:
             sigbuf.appendByte('C');
             break;
         case INT:
             sigbuf.appendByte('I');
             break;
         case LONG:
             sigbuf.appendByte('J');
             break;
         case FLOAT:
             sigbuf.appendByte('F');
             break;
         case DOUBLE:
             sigbuf.appendByte('D');
             break;
         case BOOLEAN:
             sigbuf.appendByte('Z');
             break;
         case VOID:
             sigbuf.appendByte('V');
             break;
         case CLASS:
             sigbuf.appendByte('L');
             assembleClassSig(type);
             sigbuf.appendByte(';');
             break;
         case ARRAY:
             ArrayType at = (ArrayType)type;
             sigbuf.appendByte('[');
             assembleSig(at.elemtype);
             break;
         case METHOD:
             MethodType mt = (MethodType)type;
             sigbuf.appendByte('(');
             assembleSig(mt.argtypes);
             sigbuf.appendByte(')');
             assembleSig(mt.restype);
             if (hasTypeVar(mt.thrown)) {
                 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
                     sigbuf.appendByte('^');
                     assembleSig(l.head);
                 }
             }
             break;
         case WILDCARD: {
             WildcardType ta = (WildcardType) type;
             switch (ta.kind) {
             case SUPER:
                 sigbuf.appendByte('-');
                 assembleSig(ta.type);
                 break;
             case EXTENDS:
                 sigbuf.appendByte('+');
                 assembleSig(ta.type);
                 break;
             case UNBOUND:
                 sigbuf.appendByte('*');
                 break;
             default:
                 throw new AssertionError(ta.kind);
             }
             break;
         }
         case TYPEVAR:
             sigbuf.appendByte('T');
             sigbuf.appendName(type.tsym.name);
             sigbuf.appendByte(';');
             break;
         case FORALL:
             ForAll ft = (ForAll)type;
             assembleParamsSig(ft.tvars);
             assembleSig(ft.qtype);
             break;
         case UNINITIALIZED_THIS:
         case UNINITIALIZED_OBJECT:
             // we don't yet have a spec for uninitialized types in the
             // local variable table
             assembleSig(types.erasure(((UninitializedType)type).qtype));
             break;
         default:
             throw new AssertionError("typeSig " + type.getTag());
         }
     }
     boolean hasTypeVar(List<Type> l) {
         while (l.nonEmpty()) {
             if (l.head.hasTag(TYPEVAR)) return true;
             l = l.tail;
         }
         return false;
     }
     void assembleClassSig(Type type) {
         type = type.unannotatedType();
         ClassType ct = (ClassType)type;
         ClassSymbol c = (ClassSymbol)ct.tsym;
         enterInner(c);
         Type outer = ct.getEnclosingType();
         if (outer.allparams().nonEmpty()) {
             boolean rawOuter =
                 c.owner.kind == MTH || // either a local class
                 c.name == names.empty; // or anonymous
             assembleClassSig(rawOuter
                              ? types.erasure(outer)
                              : outer);
             sigbuf.appendByte('.');
             Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
             sigbuf.appendName(rawOuter
                               ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength()+1,c.flatname.getByteLength())
                               : c.name);
         } else {
             sigbuf.appendBytes(externalize(c.flatname));
         }
         if (ct.getTypeArguments().nonEmpty()) {
             sigbuf.appendByte('<');
             assembleSig(ct.getTypeArguments());
             sigbuf.appendByte('>');
         }
     }
     void assembleSig(List<Type> types) {
         for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail)
             assembleSig(ts.head);
     }
     void assembleParamsSig(List<Type> typarams) {
         sigbuf.appendByte('<');
         for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
             TypeVar tvar = (TypeVar)ts.head;
             sigbuf.appendName(tvar.tsym.name);
             List<Type> bounds = types.getBounds(tvar);
             if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
                 sigbuf.appendByte(':');
             }
             for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
                 sigbuf.appendByte(':');
                 assembleSig(l.head);
             }
         }
         sigbuf.appendByte('>');
     }
     /** Return signature of given type
      */
     Name typeSig(Type type) {
         Assert.check(sigbuf.length == 0);
         //- System.out.println(" ? " + type);
         assembleSig(type);
         Name n = sigbuf.toName(names);
         sigbuf.reset();
         //- System.out.println("   " + n);
         return n;
     }
     /** Given a type t, return the extended class name of its erasure in
      *  external representation.
      */
     public Name xClassName(Type t) {
         if (t.hasTag(CLASS)) {
             return names.fromUtf(externalize(t.tsym.flatName()));
         } else if (t.hasTag(ARRAY)) {
             return typeSig(types.erasure(t));
         } else {
             throw new AssertionError("xClassName");
         }
     }
 /******************************************************************
  * Writing the Constant Pool
  ******************************************************************/
     /** Thrown when the constant pool is over full.
      */
     public static class PoolOverflow extends Exception {
         private static final long serialVersionUID = 0;
         public PoolOverflow() {}
     }
     public static class StringOverflow extends Exception {
         private static final long serialVersionUID = 0;
         public final String value;
         public StringOverflow(String s) {
             value = s;
         }
     }
     /** Write constant pool to pool buffer.
      *  Note: during writing, constant pool
      *  might grow since some parts of constants still need to be entered.
      */
     void writePool(Pool pool) throws PoolOverflow, StringOverflow {
         int poolCountIdx = poolbuf.length;
         poolbuf.appendChar(0);
         int i = 1;
         while (i < pool.pp) {
             Object value = pool.pool[i];
             Assert.checkNonNull(value);
             if (value instanceof Method)
                 value = ((Method)value).m;
             else if (value instanceof Variable)
                 value = ((Variable)value).v;
             if (value instanceof MethodSymbol) {
                 MethodSymbol m = (MethodSymbol)value;
                 if (!m.isDynamic()) {
                     poolbuf.appendByte((m.owner.flags() & INTERFACE) != 0
                               ? CONSTANT_InterfaceMethodref
                               : CONSTANT_Methodref);
                     poolbuf.appendChar(pool.put(m.owner));
                     poolbuf.appendChar(pool.put(nameType(m)));
                 } else {
                     //invokedynamic
                     DynamicMethodSymbol dynSym = (DynamicMethodSymbol)m;
                     MethodHandle handle = new MethodHandle(dynSym.bsmKind, dynSym.bsm, types);
                     DynamicMethod dynMeth = new DynamicMethod(dynSym, types);
                     bootstrapMethods.put(dynMeth, handle);
                     //init cp entries
                     pool.put(names.BootstrapMethods);
                     pool.put(handle);
                     for (Object staticArg : dynSym.staticArgs) {
                         pool.put(staticArg);
                     }
                     poolbuf.appendByte(CONSTANT_InvokeDynamic);
                     poolbuf.appendChar(bootstrapMethods.size() - 1);
                     poolbuf.appendChar(pool.put(nameType(dynSym)));
                 }
             } else if (value instanceof VarSymbol) {
                 VarSymbol v = (VarSymbol)value;
                 poolbuf.appendByte(CONSTANT_Fieldref);
                 poolbuf.appendChar(pool.put(v.owner));
                 poolbuf.appendChar(pool.put(nameType(v)));
             } else if (value instanceof Name) {
                 poolbuf.appendByte(CONSTANT_Utf8);
                 byte[] bs = ((Name)value).toUtf();
                 poolbuf.appendChar(bs.length);
                 poolbuf.appendBytes(bs, 0, bs.length);
                 if (bs.length > Pool.MAX_STRING_LENGTH)
                     throw new StringOverflow(value.toString());
             } else if (value instanceof ClassSymbol) {
                 ClassSymbol c = (ClassSymbol)value;
                 if (c.owner.kind == TYP) pool.put(c.owner);
                 poolbuf.appendByte(CONSTANT_Class);
                 if (c.type.hasTag(ARRAY)) {
                     poolbuf.appendChar(pool.put(typeSig(c.type)));
                 } else {
                     poolbuf.appendChar(pool.put(names.fromUtf(externalize(c.flatname))));
                     enterInner(c);
                 }
             } else if (value instanceof NameAndType) {
                 NameAndType nt = (NameAndType)value;
                 poolbuf.appendByte(CONSTANT_NameandType);
                 poolbuf.appendChar(pool.put(nt.name));
                 poolbuf.appendChar(pool.put(typeSig(nt.uniqueType.type)));
             } else if (value instanceof Integer) {
                 poolbuf.appendByte(CONSTANT_Integer);
                 poolbuf.appendInt(((Integer)value).intValue());
             } else if (value instanceof Long) {
                 poolbuf.appendByte(CONSTANT_Long);
                 poolbuf.appendLong(((Long)value).longValue());
                 i++;
             } else if (value instanceof Float) {
                 poolbuf.appendByte(CONSTANT_Float);
                 poolbuf.appendFloat(((Float)value).floatValue());
             } else if (value instanceof Double) {
                 poolbuf.appendByte(CONSTANT_Double);
                 poolbuf.appendDouble(((Double)value).doubleValue());
                 i++;
             } else if (value instanceof String) {
                 poolbuf.appendByte(CONSTANT_String);
                 poolbuf.appendChar(pool.put(names.fromString((String)value)));
             } else if (value instanceof UniqueType) {
                 Type type = ((UniqueType)value).type;
                 if (type instanceof MethodType) {
                     poolbuf.appendByte(CONSTANT_MethodType);
                     poolbuf.appendChar(pool.put(typeSig((MethodType)type)));
                 } else {
                     if (type.hasTag(CLASS)) enterInner((ClassSymbol)type.tsym);
                     poolbuf.appendByte(CONSTANT_Class);
                     poolbuf.appendChar(pool.put(xClassName(type)));
                 }
             } else if (value instanceof MethodHandle) {
                 MethodHandle ref = (MethodHandle)value;
                 poolbuf.appendByte(CONSTANT_MethodHandle);
                 poolbuf.appendByte(ref.refKind);
                 poolbuf.appendChar(pool.put(ref.refSym));
             } else {
                 Assert.error("writePool " + value);
             }
             i++;
         }
         if (pool.pp > Pool.MAX_ENTRIES)
             throw new PoolOverflow();
         putChar(poolbuf, poolCountIdx, pool.pp);
     }
     /** Given a field, return its name.
      */
     Name fieldName(Symbol sym) {
         if (scramble && (sym.flags() & PRIVATE) != 0 ||
             scrambleAll && (sym.flags() & (PROTECTED | PUBLIC)) == 0)
             return names.fromString("_$" + sym.name.getIndex());
         else
             return sym.name;
     }
     /** Given a symbol, return its name-and-type.
      */
     NameAndType nameType(Symbol sym) {
         return new NameAndType(fieldName(sym),
                                retrofit
                                ? sym.erasure(types)
                                : sym.externalType(types), types);
         // if we retrofit, then the NameAndType has been read in as is
         // and no change is necessary. If we compile normally, the
         // NameAndType is generated from a symbol reference, and the
         // adjustment of adding an additional this$n parameter needs to be made.
     }
 /******************************************************************
  * Writing Attributes
  ******************************************************************/
     /** Write header for an attribute to data buffer and return
      *  position past attribute length index.
      */
     int writeAttr(Name attrName) {
         databuf.appendChar(pool.put(attrName));
         databuf.appendInt(0);
         return databuf.length;
     }
     /** Fill in attribute length.
      */
     void endAttr(int index) {
         putInt(databuf, index - 4, databuf.length - index);
     }
     /** Leave space for attribute count and return index for
      *  number of attributes field.
      */
     int beginAttrs() {
         databuf.appendChar(0);
         return databuf.length;
     }
     /** Fill in number of attributes.
      */
     void endAttrs(int index, int count) {
         putChar(databuf, index - 2, count);
     }
     /** Write the EnclosingMethod attribute if needed.
      *  Returns the number of attributes written (0 or 1).
      */
     int writeEnclosingMethodAttribute(ClassSymbol c) {
         if (!target.hasEnclosingMethodAttribute())
             return 0;
         return writeEnclosingMethodAttribute(names.EnclosingMethod, c);
     }
     /** Write the EnclosingMethod attribute with a specified name.
      *  Returns the number of attributes written (0 or 1).
      */
     protected int writeEnclosingMethodAttribute(Name attributeName, ClassSymbol c) {
         if (c.owner.kind != MTH && // neither a local class
             c.name != names.empty) // nor anonymous
             return 0;
         int alenIdx = writeAttr(attributeName);
         ClassSymbol enclClass = c.owner.enclClass();
         MethodSymbol enclMethod =
             (c.owner.type == null // local to init block
              || c.owner.kind != MTH) // or member init
             ? null
             : (MethodSymbol)c.owner;
         databuf.appendChar(pool.put(enclClass));
         databuf.appendChar(enclMethod == null ? 0 : pool.put(nameType(c.owner)));
         endAttr(alenIdx);
         return 1;
     }
     /** Write flag attributes; return number of attributes written.
      */
     int writeFlagAttrs(long flags) {
         int acount = 0;
         if ((flags & DEPRECATED) != 0) {
             int alenIdx = writeAttr(names.Deprecated);
             endAttr(alenIdx);
             acount++;
         }
         if ((flags & ENUM) != 0 && !target.useEnumFlag()) {
             int alenIdx = writeAttr(names.Enum);
             endAttr(alenIdx);
             acount++;
         }
         if ((flags & SYNTHETIC) != 0 && !target.useSyntheticFlag()) {
             int alenIdx = writeAttr(names.Synthetic);
             endAttr(alenIdx);
             acount++;
         }
         if ((flags & BRIDGE) != 0 && !target.useBridgeFlag()) {
             int alenIdx = writeAttr(names.Bridge);
             endAttr(alenIdx);
             acount++;
         }
         if ((flags & VARARGS) != 0 && !target.useVarargsFlag()) {
             int alenIdx = writeAttr(names.Varargs);
             endAttr(alenIdx);
             acount++;
         }
         if ((flags & ANNOTATION) != 0 && !target.useAnnotationFlag()) {
             int alenIdx = writeAttr(names.Annotation);
             endAttr(alenIdx);
             acount++;
         }
         return acount;
     }
     /** Write member (field or method) attributes;
      *  return number of attributes written.
      */
     int writeMemberAttrs(Symbol sym) {
         int acount = writeFlagAttrs(sym.flags());
         long flags = sym.flags();
         if (source.allowGenerics() &&
             (flags & (SYNTHETIC|BRIDGE)) != SYNTHETIC &&
             (flags & ANONCONSTR) == 0 &&
             (!types.isSameType(sym.type, sym.erasure(types)) ||
              hasTypeVar(sym.type.getThrownTypes()))) {
             // note that a local class with captured variables
             // will get a signature attribute
             int alenIdx = writeAttr(names.Signature);
             databuf.appendChar(pool.put(typeSig(sym.type)));
             endAttr(alenIdx);
             acount++;
         }
         acount += writeJavaAnnotations(sym.getRawAttributes());
         acount += writeTypeAnnotations(sym.getRawTypeAttributes());
         return acount;
     }
     /**
      * Write method parameter names attribute.
      */
     int writeMethodParametersAttr(MethodSymbol m) {
         if (m.params != null && 0 != m.params.length()) {
             int attrIndex = writeAttr(names.MethodParameters);
             databuf.appendByte(m.params.length());
             for (VarSymbol s : m.params) {
                 // TODO: expand to cover synthesized, once we figure out
                 // how to represent that.
                 final int flags = (int) s.flags() & (FINAL | SYNTHETIC);
                 // output parameter info
                 databuf.appendChar(pool.put(s.name));
                 databuf.appendInt(flags);
             }
             endAttr(attrIndex);
             return 1;
         } else
             return 0;
     }
     /** Write method parameter annotations;
      *  return number of attributes written.
      */
     int writeParameterAttrs(MethodSymbol m) {
         boolean hasVisible = false;
         boolean hasInvisible = false;
         if (m.params != null) for (VarSymbol s : m.params) {
             for (Attribute.Compound a : s.getRawAttributes()) {
                 switch (types.getRetention(a)) {
                 case SOURCE: break;
                 case CLASS: hasInvisible = true; break;
                 case RUNTIME: hasVisible = true; break;
                 default: ;// /* fail soft */ throw new AssertionError(vis);
                 }
             }
         }
         int attrCount = 0;
         if (hasVisible) {
             int attrIndex = writeAttr(names.RuntimeVisibleParameterAnnotations);
             databuf.appendByte(m.params.length());
             for (VarSymbol s : m.params) {
                 ListBuffer<Attribute.Compound> buf = new ListBuffer<Attribute.Compound>();
                 for (Attribute.Compound a : s.getRawAttributes())
                     if (types.getRetention(a) == RetentionPolicy.RUNTIME)
                         buf.append(a);
                 databuf.appendChar(buf.length());
                 for (Attribute.Compound a : buf)
                     writeCompoundAttribute(a);
             }
             endAttr(attrIndex);
             attrCount++;
         }
         if (hasInvisible) {
             int attrIndex = writeAttr(names.RuntimeInvisibleParameterAnnotations);
             databuf.appendByte(m.params.length());
             for (VarSymbol s : m.params) {
                 ListBuffer<Attribute.Compound> buf = new ListBuffer<Attribute.Compound>();
                 for (Attribute.Compound a : s.getRawAttributes())
                     if (types.getRetention(a) == RetentionPolicy.CLASS)
                         buf.append(a);
                 databuf.appendChar(buf.length());
                 for (Attribute.Compound a : buf)
                     writeCompoundAttribute(a);
             }
             endAttr(attrIndex);
             attrCount++;
         }
         return attrCount;
     }
 /**********************************************************************
  * Writing Java-language annotations (aka metadata, attributes)
  **********************************************************************/
     /** Write Java-language annotations; return number of JVM
      *  attributes written (zero or one).
      */
     int writeJavaAnnotations(List<Attribute.Compound> attrs) {
         if (attrs.isEmpty()) return 0;
         ListBuffer<Attribute.Compound> visibles = new ListBuffer<Attribute.Compound>();
         ListBuffer<Attribute.Compound> invisibles = new ListBuffer<Attribute.Compound>();
         for (Attribute.Compound a : attrs) {
             switch (types.getRetention(a)) {
             case SOURCE: break;
             case CLASS: invisibles.append(a); break;
             case RUNTIME: visibles.append(a); break;
             default: ;// /* fail soft */ throw new AssertionError(vis);
             }
         }
         int attrCount = 0;
         if (visibles.length() != 0) {
             int attrIndex = writeAttr(names.RuntimeVisibleAnnotations);
             databuf.appendChar(visibles.length());
             for (Attribute.Compound a : visibles)
                 writeCompoundAttribute(a);
             endAttr(attrIndex);
             attrCount++;
         }
         if (invisibles.length() != 0) {
             int attrIndex = writeAttr(names.RuntimeInvisibleAnnotations);
             databuf.appendChar(invisibles.length());
             for (Attribute.Compound a : invisibles)
                 writeCompoundAttribute(a);
             endAttr(attrIndex);
             attrCount++;
         }
         return attrCount;
     }
     int writeTypeAnnotations(List<Attribute.TypeCompound> typeAnnos) {
         if (typeAnnos.isEmpty()) return 0;
         ListBuffer<Attribute.TypeCompound> visibles = ListBuffer.lb();
         ListBuffer<Attribute.TypeCompound> invisibles = ListBuffer.lb();
         for (Attribute.TypeCompound tc : typeAnnos) {
             if (tc.position == null || tc.position.type == TargetType.UNKNOWN) {
                 boolean found = false;
                 // TODO: the position for the container annotation of a
                 // repeating type annotation has to be set.
                 // This cannot be done when the container is created, because
                 // then the position is not determined yet.
                 // How can we link these pieces better together?
                 if (tc.values.size() == 1) {
                     Pair<MethodSymbol, Attribute> val = tc.values.get(0);
                     if (val.fst.getSimpleName().contentEquals("value") &&
                             val.snd instanceof Attribute.Array) {
                         Attribute.Array arr = (Attribute.Array) val.snd;
                         if (arr.values.length != 0 &&
                                 arr.values[0] instanceof Attribute.TypeCompound) {
                             TypeCompound atycomp = (Attribute.TypeCompound) arr.values[0];
                             if (atycomp.position.type != TargetType.UNKNOWN) {
                                 tc.position = atycomp.position;
                                 found = true;
                             }
                         }
                     }
                 }
                 if (!found) {
                     // This happens for nested types like @A Outer. @B Inner.
                     // For method parameters we get the annotation twice! Once with
                     // a valid position, once unknown.
                     // TODO: find a cleaner solution.
                     // System.err.println("ClassWriter: Position UNKNOWN in type annotation: " + tc);
                     continue;
                 }
             }
             if (!tc.position.emitToClassfile())
                 continue;
             switch (types.getRetention(tc)) {
             case SOURCE: break;
             case CLASS: invisibles.append(tc); break;
             case RUNTIME: visibles.append(tc); break;
             default: ;// /* fail soft */ throw new AssertionError(vis);
             }
         }
         int attrCount = 0;
         if (visibles.length() != 0) {
             int attrIndex = writeAttr(names.RuntimeVisibleTypeAnnotations);
             databuf.appendChar(visibles.length());
             for (Attribute.TypeCompound p : visibles)
                 writeTypeAnnotation(p);
             endAttr(attrIndex);
             attrCount++;
         }
         if (invisibles.length() != 0) {
             int attrIndex = writeAttr(names.RuntimeInvisibleTypeAnnotations);
             databuf.appendChar(invisibles.length());
             for (Attribute.TypeCompound p : invisibles)
                 writeTypeAnnotation(p);
             endAttr(attrIndex);
             attrCount++;
         }
         return attrCount;
     }
     /** A visitor to write an attribute including its leading
      *  single-character marker.
      */
     class AttributeWriter implements Attribute.Visitor {
         public void visitConstant(Attribute.Constant _value) {
             Object value = _value.value;
             switch (_value.type.getTag()) {
             case BYTE:
                 databuf.appendByte('B');
                 break;
             case CHAR:
                 databuf.appendByte('C');
                 break;
             case SHORT:
                 databuf.appendByte('S');
                 break;
             case INT:
                 databuf.appendByte('I');
                 break;
             case LONG:
                 databuf.appendByte('J');
                 break;
             case FLOAT:
                 databuf.appendByte('F');
                 break;
             case DOUBLE:
                 databuf.appendByte('D');
                 break;
             case BOOLEAN:
                 databuf.appendByte('Z');
                 break;
             case CLASS:
                 Assert.check(value instanceof String);
                 databuf.appendByte('s');
                 value = names.fromString(value.toString()); // CONSTANT_Utf8
                 break;
             default:
                 throw new AssertionError(_value.type);
             }
             databuf.appendChar(pool.put(value));
         }
         public void visitEnum(Attribute.Enum e) {
             databuf.appendByte('e');
             databuf.appendChar(pool.put(typeSig(e.value.type)));
             databuf.appendChar(pool.put(e.value.name));
         }
         public void visitClass(Attribute.Class clazz) {
             databuf.appendByte('c');
             databuf.appendChar(pool.put(typeSig(clazz.classType)));
         }
         public void visitCompound(Attribute.Compound compound) {
             databuf.appendByte('@');
             writeCompoundAttribute(compound);
         }
         public void visitError(Attribute.Error x) {
             throw new AssertionError(x);
         }
         public void visitArray(Attribute.Array array) {
             databuf.appendByte('[');
             databuf.appendChar(array.values.length);
             for (Attribute a : array.values) {
                 a.accept(this);
             }
         }
     }
     AttributeWriter awriter = new AttributeWriter();
     /** Write a compound attribute excluding the '@' marker. */
     void writeCompoundAttribute(Attribute.Compound c) {
         databuf.appendChar(pool.put(typeSig(c.type)));
         databuf.appendChar(c.values.length());
         for (Pair<Symbol.MethodSymbol,Attribute> p : c.values) {
             databuf.appendChar(pool.put(p.fst.name));
             p.snd.accept(awriter);
         }
     }
     void writeTypeAnnotation(Attribute.TypeCompound c) {
         writePosition(c.position);
         writeCompoundAttribute(c);
     }
     void writePosition(TypeAnnotationPosition p) {
         databuf.appendByte(p.type.targetTypeValue()); // TargetType tag is a byte
         switch (p.type) {
         // type cast
         case CAST:
         // instanceof
         case INSTANCEOF:
         // new expression
         case NEW:
             databuf.appendChar(p.offset);
             break;
         // local variable
         case LOCAL_VARIABLE:
         // resource variable
         case RESOURCE_VARIABLE:
             databuf.appendChar(p.lvarOffset.length);  // for table length
             for (int i = 0; i < p.lvarOffset.length; ++i) {
                 databuf.appendChar(p.lvarOffset[i]);
                 databuf.appendChar(p.lvarLength[i]);
                 databuf.appendChar(p.lvarIndex[i]);
             }
             break;
         // exception parameter
         case EXCEPTION_PARAMETER:
             databuf.appendByte(p.exception_index);
             break;
         // method receiver
         case METHOD_RECEIVER:
             // Do nothing
             break;
         // type parameter
         case CLASS_TYPE_PARAMETER:
         case METHOD_TYPE_PARAMETER:
             databuf.appendByte(p.parameter_index);
             break;
         // type parameter bound
         case CLASS_TYPE_PARAMETER_BOUND:
         case METHOD_TYPE_PARAMETER_BOUND:
             databuf.appendByte(p.parameter_index);
             databuf.appendByte(p.bound_index);
             break;
         // class extends or implements clause
         case CLASS_EXTENDS:
             databuf.appendChar(p.type_index);
             break;
         // throws
         case THROWS:
             databuf.appendChar(p.type_index);
             break;
         // method parameter
         case METHOD_FORMAL_PARAMETER:
             databuf.appendByte(p.parameter_index);
             break;
         // method/constructor/reference type argument
         case CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
         case METHOD_INVOCATION_TYPE_ARGUMENT:
         case METHOD_REFERENCE_TYPE_ARGUMENT:
             databuf.appendChar(p.offset);
             databuf.appendByte(p.type_index);
             break;
         // We don't need to worry about these
         case METHOD_RETURN:
         case FIELD:
             break;
         // lambda formal parameter
         case LAMBDA_FORMAL_PARAMETER:
             databuf.appendByte(p.parameter_index);
             break;
         case UNKNOWN:
             throw new AssertionError("jvm.ClassWriter: UNKNOWN target type should never occur!");
         default:
             throw new AssertionError("jvm.ClassWriter: Unknown target type for position: " + p);
         }
         { // Append location data for generics/arrays.
             databuf.appendByte(p.location.size());
             java.util.List<Integer> loc = TypeAnnotationPosition.getBinaryFromTypePath(p.location);
             for (int i : loc)
                 databuf.appendByte((byte)i);
         }
     }
 /**********************************************************************
  * Writing Objects
  **********************************************************************/
     /** Enter an inner class into the `innerClasses' set/queue.
      */
     void enterInner(ClassSymbol c) {
         if (c.type.isCompound()) {
             throw new AssertionError("Unexpected intersection type: " + c.type);
         }
         try {
             c.complete();
         } catch (CompletionFailure ex) {
             System.err.println("error: " + c + ": " + ex.getMessage());
             throw ex;
         }
         if (!c.type.hasTag(CLASS)) return; // arrays
         if (pool != null && // pool might be null if called from xClassName
             c.owner.enclClass() != null &&
             (innerClasses == null || !innerClasses.contains(c))) {
 //          log.errWriter.println("enter inner " + c);//DEBUG
             enterInner(c.owner.enclClass());
             pool.put(c);
             pool.put(c.name);
             if (innerClasses == null) {
                 innerClasses = new HashSet<ClassSymbol>();
                 innerClassesQueue = new ListBuffer<ClassSymbol>();
                 pool.put(names.InnerClasses);
             }
             innerClasses.add(c);
             innerClassesQueue.append(c);
         }
     }
     /** Write "inner classes" attribute.
      */
     void writeInnerClasses() {
         int alenIdx = writeAttr(names.InnerClasses);
         databuf.appendChar(innerClassesQueue.length());
         for (List<ClassSymbol> l = innerClassesQueue.toList();
              l.nonEmpty();
              l = l.tail) {
             ClassSymbol inner = l.head;
             char flags = (char) adjustFlags(inner.flags_field);
             if ((flags & INTERFACE) != 0) flags |= ABSTRACT; // Interfaces are always ABSTRACT
             if (inner.name.isEmpty()) flags &= ~FINAL; // Anonymous class: unset FINAL flag
             if (dumpInnerClassModifiers) {
                 PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
                 pw.println("INNERCLASS  " + inner.name);
                 pw.println("---" + flagNames(flags));
             }
             databuf.appendChar(pool.get(inner));
             databuf.appendChar(
                 inner.owner.kind == TYP ? pool.get(inner.owner) : 0);
             databuf.appendChar(
                 !inner.name.isEmpty() ? pool.get(inner.name) : 0);
             databuf.appendChar(flags);
         }
         endAttr(alenIdx);
     }
     /** Write "bootstrapMethods" attribute.
      */
     void writeBootstrapMethods() {
         int alenIdx = writeAttr(names.BootstrapMethods);
         databuf.appendChar(bootstrapMethods.size());
         for (Map.Entry<DynamicMethod, MethodHandle> entry : bootstrapMethods.entrySet()) {
             DynamicMethod dmeth = entry.getKey();
             DynamicMethodSymbol dsym = (DynamicMethodSymbol)dmeth.baseSymbol();
             //write BSM handle
             databuf.appendChar(pool.get(entry.getValue()));
             //write static args length
             databuf.appendChar(dsym.staticArgs.length);
             //write static args array
             Object[] uniqueArgs = dmeth.uniqueStaticArgs;
             for (Object o : uniqueArgs) {
                 databuf.appendChar(pool.get(o));
             }
         }
         endAttr(alenIdx);
     }
     /** Write field symbol, entering all references into constant pool.
      */
     void writeField(VarSymbol v) {
         int flags = adjustFlags(v.flags());
         databuf.appendChar(flags);
         if (dumpFieldModifiers) {
             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
             pw.println("FIELD  " + fieldName(v));
             pw.println("---" + flagNames(v.flags()));
         }
         databuf.appendChar(pool.put(fieldName(v)));
         databuf.appendChar(pool.put(typeSig(v.erasure(types))));
         int acountIdx = beginAttrs();
         int acount = 0;
         if (v.getConstValue() != null) {
             int alenIdx = writeAttr(names.ConstantValue);
             databuf.appendChar(pool.put(v.getConstValue()));
             endAttr(alenIdx);
             acount++;
         }
         acount += writeMemberAttrs(v);
         endAttrs(acountIdx, acount);
     }
     /** Write method symbol, entering all references into constant pool.
      */
     void writeMethod(MethodSymbol m) {
         int flags = adjustFlags(m.flags());
         databuf.appendChar(flags);
         if (dumpMethodModifiers) {
             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
             pw.println("METHOD  " + fieldName(m));
             pw.println("---" + flagNames(m.flags()));
         }
         databuf.appendChar(pool.put(fieldName(m)));
         databuf.appendChar(pool.put(typeSig(m.externalType(types))));
         int acountIdx = beginAttrs();
         int acount = 0;
         if (m.code != null) {
             int alenIdx = writeAttr(names.Code);
             writeCode(m.code);
             m.code = null; // to conserve space
             endAttr(alenIdx);
             acount++;
         }
         List<Type> thrown = m.erasure(types).getThrownTypes();
         if (thrown.nonEmpty()) {
             int alenIdx = writeAttr(names.Exceptions);
             databuf.appendChar(thrown.length());
             for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
                 databuf.appendChar(pool.put(l.head.tsym));
             endAttr(alenIdx);
             acount++;
         }
         if (m.defaultValue != null) {
             int alenIdx = writeAttr(names.AnnotationDefault);
             m.defaultValue.accept(awriter);
             endAttr(alenIdx);
             acount++;
         }
         if (options.isSet(PARAMETERS))
             acount += writeMethodParametersAttr(m);
         acount += writeMemberAttrs(m);
         acount += writeParameterAttrs(m);
         endAttrs(acountIdx, acount);
     }
     /** Write code attribute of method.
      */
     void writeCode(Code code) {
         databuf.appendChar(code.max_stack);
         databuf.appendChar(code.max_locals);
         databuf.appendInt(code.cp);
         databuf.appendBytes(code.code, 0, code.cp);
         databuf.appendChar(code.catchInfo.length());
         for (List<char[]> l = code.catchInfo.toList();
              l.nonEmpty();
              l = l.tail) {
             for (int i = 0; i < l.head.length; i++)
                 databuf.appendChar(l.head[i]);
         }
         int acountIdx = beginAttrs();
         int acount = 0;
         if (code.lineInfo.nonEmpty()) {
             int alenIdx = writeAttr(names.LineNumberTable);
             databuf.appendChar(code.lineInfo.length());
             for (List<char[]> l = code.lineInfo.reverse();
                  l.nonEmpty();
                  l = l.tail)
                 for (int i = 0; i < l.head.length; i++)
                     databuf.appendChar(l.head[i]);
             endAttr(alenIdx);
             acount++;
         }
         if (genCrt && (code.crt != null)) {
             CRTable crt = code.crt;
             int alenIdx = writeAttr(names.CharacterRangeTable);
             int crtIdx = beginAttrs();
             int crtEntries = crt.writeCRT(databuf, code.lineMap, log);
             endAttrs(crtIdx, crtEntries);
             endAttr(alenIdx);
             acount++;
         }
         // counter for number of generic local variables
         int nGenericVars = 0;
         if (code.varBufferSize > 0) {
             int alenIdx = writeAttr(names.LocalVariableTable);
             databuf.appendChar(code.varBufferSize);
             for (int i=0; i<code.varBufferSize; i++) {
                 Code.LocalVar var = code.varBuffer[i];
                 // write variable info
                 Assert.check(var.start_pc >= 0
                         && var.start_pc <= code.cp);
                 databuf.appendChar(var.start_pc);
                 Assert.check(var.length >= 0
                         && (var.start_pc + var.length) <= code.cp);
                 databuf.appendChar(var.length);
                 VarSymbol sym = var.sym;
                 databuf.appendChar(pool.put(sym.name));
                 Type vartype = sym.erasure(types);
                 if (needsLocalVariableTypeEntry(sym.type))
                     nGenericVars++;
                 databuf.appendChar(pool.put(typeSig(vartype)));
                 databuf.appendChar(var.reg);
             }
             endAttr(alenIdx);
             acount++;
         }
         if (nGenericVars > 0) {
             int alenIdx = writeAttr(names.LocalVariableTypeTable);
             databuf.appendChar(nGenericVars);
             int count = 0;
             for (int i=0; i<code.varBufferSize; i++) {
                 Code.LocalVar var = code.varBuffer[i];
                 VarSymbol sym = var.sym;
                 if (!needsLocalVariableTypeEntry(sym.type))
                     continue;
                 count++;
                 // write variable info
                 databuf.appendChar(var.start_pc);
                 databuf.appendChar(var.length);
                 databuf.appendChar(pool.put(sym.name));
                 databuf.appendChar(pool.put(typeSig(sym.type)));
                 databuf.appendChar(var.reg);
             }
             Assert.check(count == nGenericVars);
             endAttr(alenIdx);
             acount++;
         }
         if (code.stackMapBufferSize > 0) {
             if (debugstackmap) System.out.println("Stack map for " + code.meth);
             int alenIdx = writeAttr(code.stackMap.getAttributeName(names));
             writeStackMap(code);
             endAttr(alenIdx);
             acount++;
         }
         endAttrs(acountIdx, acount);
     }
     //where
     private boolean needsLocalVariableTypeEntry(Type t) {
         //a local variable needs a type-entry if its type T is generic
         //(i.e. |T| != T) and if it's not an intersection type (not supported
         //in signature attribute grammar)
         return (!types.isSameType(t, types.erasure(t)) &&
                 !t.isCompound());
     }
     void writeStackMap(Code code) {
         int nframes = code.stackMapBufferSize;
         if (debugstackmap) System.out.println(" nframes = " + nframes);
         databuf.appendChar(nframes);
         switch (code.stackMap) {
         case CLDC:
             for (int i=0; i<nframes; i++) {
                 if (debugstackmap) System.out.print("  " + i + ":");
                 Code.StackMapFrame frame = code.stackMapBuffer[i];
                 // output PC
                 if (debugstackmap) System.out.print(" pc=" + frame.pc);
                 databuf.appendChar(frame.pc);
                 // output locals
                 int localCount = 0;
                 for (int j=0; j<frame.locals.length;
                      j += (target.generateEmptyAfterBig() ? 1 : Code.width(frame.locals[j]))) {
                     localCount++;
                 }
                 if (debugstackmap) System.out.print(" nlocals=" +
                                                     localCount);
                 databuf.appendChar(localCount);
                 for (int j=0; j<frame.locals.length;
                      j += (target.generateEmptyAfterBig() ? 1 : Code.width(frame.locals[j]))) {
                     if (debugstackmap) System.out.print(" local[" + j + "]=");
                     writeStackMapType(frame.locals[j]);
                 }
                 // output stack
                 int stackCount = 0;
                 for (int j=0; j<frame.stack.length;
                      j += (target.generateEmptyAfterBig() ? 1 : Code.width(frame.stack[j]))) {
                     stackCount++;
                 }
                 if (debugstackmap) System.out.print(" nstack=" +
                                                     stackCount);
                 databuf.appendChar(stackCount);
                 for (int j=0; j<frame.stack.length;
                      j += (target.generateEmptyAfterBig() ? 1 : Code.width(frame.stack[j]))) {
                     if (debugstackmap) System.out.print(" stack[" + j + "]=");
                     writeStackMapType(frame.stack[j]);
                 }
                 if (debugstackmap) System.out.println();
             }
             break;
         case JSR202: {
             Assert.checkNull(code.stackMapBuffer);
             for (int i=0; i<nframes; i++) {
                 if (debugstackmap) System.out.print("  " + i + ":");
                 StackMapTableFrame frame = code.stackMapTableBuffer[i];
                 frame.write(this);
                 if (debugstackmap) System.out.println();
             }
             break;
         }
         default:
             throw new AssertionError("Unexpected stackmap format value");
         }
     }
         //where
         void writeStackMapType(Type t) {
             if (t == null) {
                 if (debugstackmap) System.out.print("empty");
                 databuf.appendByte(0);
             }
             else switch(t.getTag()) {
             case BYTE:
             case CHAR:
             case SHORT:
             case INT:
             case BOOLEAN:
                 if (debugstackmap) System.out.print("int");
                 databuf.appendByte(1);
                 break;
             case FLOAT:
                 if (debugstackmap) System.out.print("float");
                 databuf.appendByte(2);
                 break;
             case DOUBLE:
                 if (debugstackmap) System.out.print("double");
                 databuf.appendByte(3);
                 break;
             case LONG:
                 if (debugstackmap) System.out.print("long");
                 databuf.appendByte(4);
                 break;
             case BOT: // null
                 if (debugstackmap) System.out.print("null");
                 databuf.appendByte(5);
                 break;
             case CLASS:
             case ARRAY:
                 if (debugstackmap) System.out.print("object(" + t + ")");
                 databuf.appendByte(7);
                 databuf.appendChar(pool.put(t));
                 break;
             case TYPEVAR:
                 if (debugstackmap) System.out.print("object(" + types.erasure(t).tsym + ")");
                 databuf.appendByte(7);
                 databuf.appendChar(pool.put(types.erasure(t).tsym));
                 break;
             case UNINITIALIZED_THIS:
                 if (debugstackmap) System.out.print("uninit_this");
                 databuf.appendByte(6);
                 break;
             case UNINITIALIZED_OBJECT:
                 { UninitializedType uninitType = (UninitializedType)t;
                 databuf.appendByte(8);
                 if (debugstackmap) System.out.print("uninit_object@" + uninitType.offset);
                 databuf.appendChar(uninitType.offset);
                 }
                 break;
             default:
                 throw new AssertionError();
             }
         }
     /** An entry in the JSR202 StackMapTable */
     abstract static class StackMapTableFrame {
         abstract int getFrameType();
         void write(ClassWriter writer) {
             int frameType = getFrameType();
             writer.databuf.appendByte(frameType);
             if (writer.debugstackmap) System.out.print(" frame_type=" + frameType);
         }
         static class SameFrame extends StackMapTableFrame {
             final int offsetDelta;
             SameFrame(int offsetDelta) {
                 this.offsetDelta = offsetDelta;
             }
             int getFrameType() {
                 return (offsetDelta < SAME_FRAME_SIZE) ? offsetDelta : SAME_FRAME_EXTENDED;
             }
             @Override
             void write(ClassWriter writer) {
                 super.write(writer);
                 if (getFrameType() == SAME_FRAME_EXTENDED) {
                     writer.databuf.appendChar(offsetDelta);
                     if (writer.debugstackmap){
                         System.out.print(" offset_delta=" + offsetDelta);
                     }
                 }
             }
         }
         static class SameLocals1StackItemFrame extends StackMapTableFrame {
             final int offsetDelta;
             final Type stack;
             SameLocals1StackItemFrame(int offsetDelta, Type stack) {
                 this.offsetDelta = offsetDelta;
                 this.stack = stack;
             }
             int getFrameType() {
                 return (offsetDelta < SAME_FRAME_SIZE) ?
                        (SAME_FRAME_SIZE + offsetDelta) :
                        SAME_LOCALS_1_STACK_ITEM_EXTENDED;
             }
             @Override
             void write(ClassWriter writer) {
                 super.write(writer);
                 if (getFrameType() == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
                     writer.databuf.appendChar(offsetDelta);
                     if (writer.debugstackmap) {
                         System.out.print(" offset_delta=" + offsetDelta);
                     }
                 }
                 if (writer.debugstackmap) {
                     System.out.print(" stack[" + 0 + "]=");
                 }
                 writer.writeStackMapType(stack);
             }
         }
         static class ChopFrame extends StackMapTableFrame {
             final int frameType;
             final int offsetDelta;
             ChopFrame(int frameType, int offsetDelta) {
                 this.frameType = frameType;
                 this.offsetDelta = offsetDelta;
             }
             int getFrameType() { return frameType; }
             @Override
             void write(ClassWriter writer) {
                 super.write(writer);
                 writer.databuf.appendChar(offsetDelta);
                 if (writer.debugstackmap) {
                     System.out.print(" offset_delta=" + offsetDelta);
                 }
             }
         }
         static class AppendFrame extends StackMapTableFrame {
             final int frameType;
             final int offsetDelta;
             final Type[] locals;
             AppendFrame(int frameType, int offsetDelta, Type[] locals) {
                 this.frameType = frameType;
                 this.offsetDelta = offsetDelta;
                 this.locals = locals;
             }
             int getFrameType() { return frameType; }
             @Override
             void write(ClassWriter writer) {
                 super.write(writer);
                 writer.databuf.appendChar(offsetDelta);
                 if (writer.debugstackmap) {
                     System.out.print(" offset_delta=" + offsetDelta);
                 }
                 for (int i=0; i<locals.length; i++) {
                      if (writer.debugstackmap) System.out.print(" locals[" + i + "]=");
                      writer.writeStackMapType(locals[i]);
                 }
             }
         }
         static class FullFrame extends StackMapTableFrame {
             final int offsetDelta;
             final Type[] locals;
             final Type[] stack;
             FullFrame(int offsetDelta, Type[] locals, Type[] stack) {
                 this.offsetDelta = offsetDelta;
                 this.locals = locals;
                 this.stack = stack;
             }
             int getFrameType() { return FULL_FRAME; }
             @Override
             void write(ClassWriter writer) {
                 super.write(writer);
                 writer.databuf.appendChar(offsetDelta);
                 writer.databuf.appendChar(locals.length);
                 if (writer.debugstackmap) {
                     System.out.print(" offset_delta=" + offsetDelta);
                     System.out.print(" nlocals=" + locals.length);
                 }
                 for (int i=0; i<locals.length; i++) {
                     if (writer.debugstackmap) System.out.print(" locals[" + i + "]=");
                     writer.writeStackMapType(locals[i]);
                 }
                 writer.databuf.appendChar(stack.length);
                 if (writer.debugstackmap) { System.out.print(" nstack=" + stack.length); }
                 for (int i=0; i<stack.length; i++) {
                     if (writer.debugstackmap) System.out.print(" stack[" + i + "]=");
                     writer.writeStackMapType(stack[i]);
                 }
             }
         }
        /** Compare this frame with the previous frame and produce
         *  an entry of compressed stack map frame. */
         static StackMapTableFrame getInstance(Code.StackMapFrame this_frame,
                                               int prev_pc,
                                               Type[] prev_locals,
                                               Types types) {
             Type[] locals = this_frame.locals;
             Type[] stack = this_frame.stack;
             int offset_delta = this_frame.pc - prev_pc - 1;
             if (stack.length == 1) {
                 if (locals.length == prev_locals.length
                     && compare(prev_locals, locals, types) == 0) {
                     return new SameLocals1StackItemFrame(offset_delta, stack[0]);
                 }
             } else if (stack.length == 0) {
                 int diff_length = compare(prev_locals, locals, types);
                 if (diff_length == 0) {
                     return new SameFrame(offset_delta);
                 } else if (-MAX_LOCAL_LENGTH_DIFF < diff_length && diff_length < 0) {
                     // APPEND
                     Type[] local_diff = new Type[-diff_length];
                     for (int i=prev_locals.length, j=0; i<locals.length; i++,j++) {
                         local_diff[j] = locals[i];
                     }
                     return new AppendFrame(SAME_FRAME_EXTENDED - diff_length,
                                            offset_delta,
                                            local_diff);
                 } else if (0 < diff_length && diff_length < MAX_LOCAL_LENGTH_DIFF) {
                     // CHOP
                     return new ChopFrame(SAME_FRAME_EXTENDED - diff_length,
                                          offset_delta);
                 }
             }
             // FULL_FRAME
             return new FullFrame(offset_delta, locals, stack);
         }
         static boolean isInt(Type t) {
             return (t.getTag().isStrictSubRangeOf(INT)  || t.hasTag(BOOLEAN));
         }
         static boolean isSameType(Type t1, Type t2, Types types) {
             if (t1 == null) { return t2 == null; }
             if (t2 == null) { return false; }
             if (isInt(t1) && isInt(t2)) { return true; }
             if (t1.hasTag(UNINITIALIZED_THIS)) {
                 return t2.hasTag(UNINITIALIZED_THIS);
             } else if (t1.hasTag(UNINITIALIZED_OBJECT)) {
                 if (t2.hasTag(UNINITIALIZED_OBJECT)) {
                     return ((UninitializedType)t1).offset == ((UninitializedType)t2).offset;
                 } else {
                     return false;
                 }
             } else if (t2.hasTag(UNINITIALIZED_THIS) || t2.hasTag(UNINITIALIZED_OBJECT)) {
                 return false;
             }
             return types.isSameType(t1, t2);
         }
         static int compare(Type[] arr1, Type[] arr2, Types types) {
             int diff_length = arr1.length - arr2.length;
             if (diff_length > MAX_LOCAL_LENGTH_DIFF || diff_length < -MAX_LOCAL_LENGTH_DIFF) {
                 return Integer.MAX_VALUE;
             }
             int len = (diff_length > 0) ? arr2.length : arr1.length;
             for (int i=0; i<len; i++) {
                 if (!isSameType(arr1[i], arr2[i], types)) {
                     return Integer.MAX_VALUE;
                 }
             }
             return diff_length;
         }
     }
     void writeFields(Scope.Entry e) {
         // process them in reverse sibling order;
         // i.e., process them in declaration order.
         List<VarSymbol> vars = List.nil();
         for (Scope.Entry i = e; i != null; i = i.sibling) {
             if (i.sym.kind == VAR) vars = vars.prepend((VarSymbol)i.sym);
         }
         while (vars.nonEmpty()) {
             writeField(vars.head);
             vars = vars.tail;
         }
     }
     void writeMethods(Scope.Entry e) {
         List<MethodSymbol> methods = List.nil();
         for (Scope.Entry i = e; i != null; i = i.sibling) {
             if (i.sym.kind == MTH && (i.sym.flags() & HYPOTHETICAL) == 0)
                 methods = methods.prepend((MethodSymbol)i.sym);
         }
         while (methods.nonEmpty()) {
             writeMethod(methods.head);
             methods = methods.tail;
         }
     }
     /** Emit a class file for a given class.
      *  @param c      The class from which a class file is generated.
      */
     public JavaFileObject writeClass(ClassSymbol c)
         throws IOException, PoolOverflow, StringOverflow
     {
         JavaFileObject outFile
             = fileManager.getJavaFileForOutput(CLASS_OUTPUT,
                                                c.flatname.toString(),
                                                JavaFileObject.Kind.CLASS,
                                                c.sourcefile);
         OutputStream out = outFile.openOutputStream();
         try {
             writeClassFile(out, c);
             if (verbose)
                 log.printVerbose("wrote.file", outFile);
             out.close();
             out = null;
         } finally {
             if (out != null) {
                 // if we are propogating an exception, delete the file
                 out.close();
                 outFile.delete();
                 outFile = null;
             }
         }
         return outFile; // may be null if write failed
     }
     /** Write class `c' to outstream `out'.
      */
     public void writeClassFile(OutputStream out, ClassSymbol c)
         throws IOException, PoolOverflow, StringOverflow {
         Assert.check((c.flags() & COMPOUND) == 0);
         databuf.reset();
         poolbuf.reset();
         sigbuf.reset();
         pool = c.pool;
         innerClasses = null;
         innerClassesQueue = null;
         bootstrapMethods = new LinkedHashMap<DynamicMethod, MethodHandle>();
         Type supertype = types.supertype(c.type);
         List<Type> interfaces = types.interfaces(c.type);
         List<Type> typarams = c.type.getTypeArguments();
         int flags = adjustFlags(c.flags() & ~DEFAULT);
         if ((flags & PROTECTED) != 0) flags |= PUBLIC;
         flags = flags & ClassFlags & ~STRICTFP;
         if ((flags & INTERFACE) == 0) flags |= ACC_SUPER;
         if (c.isInner() && c.name.isEmpty()) flags &= ~FINAL;
         if (dumpClassModifiers) {
             PrintWriter pw = log.getWriter(Log.WriterKind.ERROR);
             pw.println();
             pw.println("CLASSFILE  " + c.getQualifiedName());
             pw.println("---" + flagNames(flags));
         }
         databuf.appendChar(flags);
         databuf.appendChar(pool.put(c));
         databuf.appendChar(supertype.hasTag(CLASS) ? pool.put(supertype.tsym) : 0);
         databuf.appendChar(interfaces.length());
         for (List<Type> l = interfaces; l.nonEmpty(); l = l.tail)
             databuf.appendChar(pool.put(l.head.tsym));
         int fieldsCount = 0;
         int methodsCount = 0;
         for (Scope.Entry e = c.members().elems; e != null; e = e.sibling) {
             switch (e.sym.kind) {
             case VAR: fieldsCount++; break;
             case MTH: if ((e.sym.flags() & HYPOTHETICAL) == 0) methodsCount++;
                       break;
             case TYP: enterInner((ClassSymbol)e.sym); break;
             default : Assert.error();
             }
         }
         if (c.trans_local != null) {
             for (ClassSymbol local : c.trans_local) {
                 enterInner(local);
             }
         }
         databuf.appendChar(fieldsCount);
         writeFields(c.members().elems);
         databuf.appendChar(methodsCount);
         writeMethods(c.members().elems);
         int acountIdx = beginAttrs();
         int acount = 0;
         boolean sigReq =
             typarams.length() != 0 || supertype.allparams().length() != 0;
         for (List<Type> l = interfaces; !sigReq && l.nonEmpty(); l = l.tail)
             sigReq = l.head.allparams().length() != 0;
         if (sigReq) {
             Assert.check(source.allowGenerics());
             int alenIdx = writeAttr(names.Signature);
             if (typarams.length() != 0) assembleParamsSig(typarams);
             assembleSig(supertype);
             for (List<Type> l = interfaces; l.nonEmpty(); l = l.tail)
                 assembleSig(l.head);
             databuf.appendChar(pool.put(sigbuf.toName(names)));
             sigbuf.reset();
             endAttr(alenIdx);
             acount++;
         }
         if (c.sourcefile != null && emitSourceFile) {
             int alenIdx = writeAttr(names.SourceFile);
             // WHM 6/29/1999: Strip file path prefix.  We do it here at
             // the last possible moment because the sourcefile may be used
             // elsewhere in error diagnostics. Fixes 4241573.
             //databuf.appendChar(c.pool.put(c.sourcefile));
             String simpleName = BaseFileObject.getSimpleName(c.sourcefile);
             databuf.appendChar(c.pool.put(names.fromString(simpleName)));
             endAttr(alenIdx);
             acount++;
         }
         if (genCrt) {
             // Append SourceID attribute
             int alenIdx = writeAttr(names.SourceID);
             databuf.appendChar(c.pool.put(names.fromString(Long.toString(getLastModified(c.sourcefile)))));
             endAttr(alenIdx);
             acount++;
             // Append CompilationID attribute
             alenIdx = writeAttr(names.CompilationID);
             databuf.appendChar(c.pool.put(names.fromString(Long.toString(System.currentTimeMillis()))));
             endAttr(alenIdx);
             acount++;
         }
         acount += writeFlagAttrs(c.flags());
         acount += writeJavaAnnotations(c.getRawAttributes());
         acount += writeTypeAnnotations(c.getRawTypeAttributes());
         acount += writeEnclosingMethodAttribute(c);
         acount += writeExtraClassAttributes(c);
         poolbuf.appendInt(JAVA_MAGIC);
         poolbuf.appendChar(target.minorVersion);
         poolbuf.appendChar(target.majorVersion);
         writePool(c.pool);
         if (innerClasses != null) {
             writeInnerClasses();
             acount++;
         }
         if (!bootstrapMethods.isEmpty()) {
             writeBootstrapMethods();
             acount++;
         }
         endAttrs(acountIdx, acount);
         poolbuf.appendBytes(databuf.elems, 0, databuf.length);
         out.write(poolbuf.elems, 0, poolbuf.length);
         pool = c.pool = null; // to conserve space
      }
     /**Allows subclasses to write additional class attributes
      *
      * @return the number of attributes written
      */
     protected int writeExtraClassAttributes(ClassSymbol c) {
         return 0;
     }
     int adjustFlags(final long flags) {
         int result = (int)flags;
         if ((flags & SYNTHETIC) != 0  && !target.useSyntheticFlag())
             result &= ~SYNTHETIC;
         if ((flags & ENUM) != 0  && !target.useEnumFlag())
             result &= ~ENUM;
         if ((flags & ANNOTATION) != 0  && !target.useAnnotationFlag())
             result &= ~ANNOTATION;
         if ((flags & BRIDGE) != 0  && target.useBridgeFlag())
             result |= ACC_BRIDGE;
         if ((flags & VARARGS) != 0  && target.useVarargsFlag())
             result |= ACC_VARARGS;
         if ((flags & DEFAULT) != 0)
             result &= ~ABSTRACT;
         return result;
     }
     long getLastModified(FileObject filename) {
         long mod = 0;
         try {
             mod = filename.getLastModified();
         } catch (SecurityException e) {
             throw new AssertionError("CRT: couldn't get source file modification date: " + e.getMessage());
         }
         return mod;
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java@71f35e4b93a5 (annotated)

src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java