/*
* @(#)ClassWriter.java 1.126 07/03/21
*
* Copyright (c) 2007 Sun Microsystems, Inc. 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package com.sun.tools.javac.jvm;
import java.io.*;
import java.util.*;
import java.util.Set;
import java.util.HashSet;
import javax.tools.JavaFileManager;
import javax.tools.FileObject;
import javax.tools.JavaFileObject;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.List;
import static com.sun.tools.javac.code.BoundKind.*;
import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Kinds.*;
import static com.sun.tools.javac.code.TypeTags.*;
import static com.sun.tools.javac.jvm.UninitializedType.*;
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 API supported by Sun Microsystems. 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>
*/
@Version("@(#)ClassWriter.java 1.126 07/03/21")
public class ClassWriter extends ClassFile {
private static my.Debug DEBUG=new my.Debug(my.Debug.ClassWriter);//我加上的
protected static final Context.Key<ClassWriter> classWriterKey =
new Context.Key<ClassWriter>();
private final Symtab syms;
private final Options options;
/** Switch: verbose output.
*/
private boolean verbose;
/** Switch: scrable private names.
*/
private boolean scramble;
/** Switch: scrable private 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 log to use for verbose output.
*/
private final Log log;
/** The name table. */
private final Name.Table 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.
*/
private ClassWriter(Context context) {
DEBUG.P(this,"ClassWriter(1)");
context.put(classWriterKey, this);
log = Log.instance(context);
names = Name.Table.instance(context);
syms = Symtab.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.get("-verbose") != null;
scramble = options.get("-scramble") != null;
scrambleAll = options.get("-scrambleAll") != null;
retrofit = options.get("-retrofit") != null;
genCrt = options.get("-Xjcov") != null;
debugstackmap = options.get("debugstackmap") != null;
emitSourceFile = options.get("-g:")==null || options.get("-g:source")!=null;
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);
//下面两个选项当用-XD-scramble与-XD-scrambleAll时为true
//scramble=true;//我加上的 当为true时可以混淆private字段的名称
//scrambleAll=true;//我加上的
DEBUG.P(0,this,"ClassWriter(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) {
StringBuffer sbuf = new StringBuffer();
int i = 0;
long f = flags & StandardFlags;//StandardFlags = 0x0fff(12位)
while (f != 0) {
if ((f & 1) != 0) sbuf.append(" " + flagName[i]);
f = f >> 1;
i++;
}
return sbuf.toString();
}
/*对应Flags类中的如下字段:
//Standard Java flags.
public static final int PUBLIC = 1<<0; 0x0001
public static final int PRIVATE = 1<<1; 0x0002
public static final int PROTECTED = 1<<2; 0x0004
public static final int STATIC = 1<<3; 0x0008
public static final int FINAL = 1<<4; 0x0010
public static final int SYNCHRONIZED = 1<<5; 0x0020//这个有点特殊，与SUPER共用
public static final int VOLATILE = 1<<6; 0x0040
public static final int TRANSIENT = 1<<7; 0x0080
public static final int NATIVE = 1<<8; 0x0100
public static final int INTERFACE = 1<<9; 0x0200
public static final int ABSTRACT = 1<<10; 0x0400
public static final int STRICTFP = 1<<11; 0x0800
*/
//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) {
try {//我加上的
DEBUG.P(this,"assembleSig(Type type)");
DEBUG.P("type="+type+" type.tag="+TypeTags.toString(type.tag));
switch (type.tag) {
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);
/*
//如:
class ExceptionA extends Exception {}
class ExceptionB extends Exception {}
class ExceptionC extends Exception {}
class Test<A extends ExceptionA, B extends ExceptionB> {
void m() throws A,B,ExceptionC{}
}
返回:typeName=()V^TA;^TB;^Ltest/jvm/ExceptionC;
*/
if (hasTypeVar(mt.thrown)) {
for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
sigbuf.appendByte('^');
assembleSig(l.head);
}
}
break;
case WILDCARD: {
//如:
//class Test<A extends Number, B extends Number, C> {
// Test<? super Integer, ? extends Number, ?> test;
//}
//返回:typeName=Ltest/jvm/Test<-Ljava/lang/Integer;+Ljava/lang/Number;*>;
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); //类型变量名称
sigbuf.appendByte(';');
break;
case FORALL:
DEBUG.P("type.tag=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.tag);
}
}finally{//我加上的
DEBUG.P(0,this,"assembleSig(Type type)");
}
}
boolean hasTypeVar(List<Type> l) {
while (l.nonEmpty()) {
if (l.head.tag == TypeTags.TYPEVAR) return true;
l = l.tail;
}
return false;
}
void assembleClassSig(Type type) {
DEBUG.P(this,"assembleClassSig(Type type)");
DEBUG.P("type="+type+" type.tag="+TypeTags.toString(type.tag));
ClassType ct = (ClassType)type;
ClassSymbol c = (ClassSymbol)ct.tsym;
enterInner(c);
Type outer = ct.getEnclosingType();
DEBUG.P("outer="+outer+" outer.tag="+TypeTags.toString(outer.tag));
DEBUG.P("outer.allparams()="+outer.allparams());
if (outer.allparams().nonEmpty()) {
boolean rawOuter =
c.owner.kind == MTH || // either a local class
c.name == names.empty; // or anonymous
DEBUG.P("rawOuter="+rawOuter);
assembleClassSig(rawOuter
? types.erasure(outer)
: outer);
sigbuf.appendByte('.');
assert c.flatname.startsWith(c.owner.enclClass().flatname);
sigbuf.appendName(rawOuter
? c.flatname.subName(c.owner.enclClass()
.flatname.len+1,
c.flatname.len)
: c.name);
} else {
DEBUG.P("c.flatname="+c.flatname);
sigbuf.appendBytes(externalize(c.flatname));
}
DEBUG.P("ct.getTypeArguments()="+ct.getTypeArguments());
if (ct.getTypeArguments().nonEmpty()) {
sigbuf.appendByte('<');
assembleSig(ct.getTypeArguments());
sigbuf.appendByte('>');
}
DEBUG.P(0,this,"assembleClassSig(Type type)");
}
void assembleSig(List<Type> types) {
for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail)
assembleSig(ts.head);
}
void assembleParamsSig(List<Type> typarams) {
DEBUG.P(this,"assembleParamsSig(1)");
DEBUG.P("typarams="+typarams);
DEBUG.P("sigbuf前="+sigbuf.toName(names));
/*如<T extends Exception & InterfaceA & InterfaceB,V extends InterfaceA & InterfaceB >
调试输出如下:
com.sun.tools.javac.jvm.ClassWriter===>assembleParamsSig(1)
-------------------------------------------------------------------------
typarams=T29132923,V23503403
sigbuf前=
sigbuf后=<T:Ljava/lang/Exception;:Lmy/test/InterfaceA;:Lmy/test/InterfaceB;V::Lmy/test/InterfaceA;:Lmy/test/InterfaceB;>
com.sun.tools.javac.jvm.ClassWriter===>assembleParamsSig(1) END
-------------------------------------------------------------------------
*/
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);
//类型变量的第一个bound是接口时多加一个冒号(":")
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('>');
DEBUG.P("sigbuf后="+sigbuf.toName(names));
DEBUG.P(0,this,"assembleParamsSig(1)");
}
/** Return signature of given type
*/
Name typeSig(Type type) {
DEBUG.P(this,"typeSig(Type type)");
assert sigbuf.length == 0;
//- System.out.println(" ? " + type);
assembleSig(type);
Name n = sigbuf.toName(names);
sigbuf.reset();
//- System.out.println(" " + n);
DEBUG.P("return typeName="+n);
DEBUG.P(0,this,"typeSig(Type type)");
return n;
}
/** Given a type t, return the extended class name of its erasure in
* external representation.
*/
public Name xClassName(Type t) {
if (t.tag == CLASS) {
return names.fromUtf(externalize(t.tsym.flatName()));
} else if (t.tag == 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 {
DEBUG.P(this,"writePool(1)");
int poolCountIdx = poolbuf.length;
//常量池的总项数先设为0，在下面的语句putChar(poolbuf, poolCountIdx, pool.pp);填上
poolbuf.appendChar(0);
int i = 1;
while (i < pool.pp) {
Object value = pool.pool[i];
assert value != null;
if (value instanceof Pool.Method)
value = ((Pool.Method)value).m;
else if (value instanceof Pool.Variable)
value = ((Pool.Variable)value).v;
//参考<<深入java虚拟机>>P129 6.4池量池那一节
if (value instanceof MethodSymbol) {
MethodSymbol m = (MethodSymbol)value;
//指tag，占1字节
poolbuf.appendByte((m.owner.flags() & INTERFACE) != 0
? CONSTANT_InterfaceMethodref
: CONSTANT_Methodref);
//指class_index，指向常量池索引,占2字节
poolbuf.appendChar(pool.put(m.owner));
//指name_and_type_index，指向常量池索引,占2字节
poolbuf.appendChar(pool.put(nameType(m)));
} 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.tag == 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.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 Type) {
Type type = (Type)value;
if (type.tag == CLASS) enterInner((ClassSymbol)type.tsym);
poolbuf.appendByte(CONSTANT_Class);
poolbuf.appendChar(pool.put(xClassName(type)));
} else {
assert false : "writePool " + value;
}
i++;
}
if (pool.pp > Pool.MAX_ENTRIES)
throw new PoolOverflow();
putChar(poolbuf, poolCountIdx, pool.pp);
DEBUG.P(0,this,"writePool(1)");
}
/** Given a field, return its name.
*/
Name fieldName(Symbol sym) {
//对于私有(PRIVATE)或非保护(PROTECTED)或非公有(PUBLIC)成员，
//将其名称搅乱，采用sym.name.index命名
if (scramble && (sym.flags() & PRIVATE) != 0 ||
scrambleAll && (sym.flags() & (PROTECTED | PUBLIC)) == 0) //这个条件还是不正确，包成员会有错误
return names.fromString("_$" + sym.name.index);
else
return sym.name;
}
/** Given a symbol, return its name-and-type.
*/
NameAndType nameType(Symbol sym) {
return new NameAndType(fieldName(sym),
retrofit
? sym.erasure(types)
: sym.externalType(types));
// if we retrofit, then the NameAndType has been read in as is
// and no change is necessary. If we compile normally, the
// NameAndType is generated from a symbol reference, and the
// adjustment of adding an additional this$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) {
DEBUG.P(this,"writeAttr(Name attrName)");
DEBUG.P("attrName="+attrName);
databuf.appendChar(pool.put(attrName));
//指attribute_length，占4字节
databuf.appendInt(0);//先初始为0，以后再回填
DEBUG.P("alenIdx="+databuf.length);//属性长度索引
DEBUG.P(0,this,"writeAttr(Name attrName)");
return databuf.length;
}
/** Fill in attribute length.
*/
void endAttr(int index) {
DEBUG.P(this,"endAttr(int index)");
DEBUG.P("attribute.index ="+(index - 4));
DEBUG.P("attribute.length="+(databuf.length - index));
putInt(databuf, index - 4, databuf.length - index);
DEBUG.P(0,this,"endAttr(int index)");
}
/** Leave space for attribute count and return index for
* number of attributes field.
*/
int beginAttrs() {
//属性个数先初始为0，返回在databuf中的索引，等找出所有属性后，
//再根据索引修改成实际的属性个数
databuf.appendChar(0);
//属性个数(arrtibutes_count)实际占两字节
//在回填时，索引位置得往下一2(见endAttrs方法)
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) {
try {//我加上的
DEBUG.P(this,"writeEnclosingMethodAttribute(1)");
DEBUG.P("target.hasEnclosingMethodAttribute()="+target.hasEnclosingMethodAttribute());
DEBUG.P("c.name="+c.name);
DEBUG.P("c.owner.kind="+Kinds.toString(c.owner.kind));
if (!target.hasEnclosingMethodAttribute() ||
c.owner.kind != MTH && // neither a local class
c.name != names.empty) // nor anonymous
return 0;
int alenIdx = writeAttr(names.EnclosingMethod);
ClassSymbol enclClass = c.owner.enclClass();
DEBUG.P("");
DEBUG.P("c.owner.type="+c.owner.type);
MethodSymbol enclMethod =
(c.owner.type == null // local to init block
|| c.owner.kind != MTH) // or member init
? null
: (MethodSymbol)c.owner;
DEBUG.P("enclClass="+enclClass);
DEBUG.P("enclMethod="+enclMethod);
if (enclMethod != null) DEBUG.P("nameType(c.owner)="+nameType(c.owner));
databuf.appendChar(pool.put(enclClass));
databuf.appendChar(enclMethod == null ? 0 : pool.put(nameType(c.owner)));
endAttr(alenIdx);
return 1;
}finally{//我加上的
DEBUG.P(0,this,"writeEnclosingMethodAttribute(1)");
}
}
/** Write flag attributes; return number of attributes written.
*/
int writeFlagAttrs(long flags) {
DEBUG.P(this,"writeFlagAttrs(long flags)");
DEBUG.P("flags="+Flags.toString(flags));
//以下6个属性的长度都为0
int acount = 0;
if ((flags & DEPRECATED) != 0) {
int alenIdx = writeAttr(names.Deprecated);
endAttr(alenIdx);
acount++;
}
//<=1.4版本的编译器得用属性来标识新的字段标志位
//参考Target类
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++;
}
DEBUG.P("acount="+acount);
DEBUG.P(0,this,"writeFlagAttrs(long flags)");
return acount;
}
/** Write member (field or method) attributes;
* return number of attributes written.
*/
int writeMemberAttrs(Symbol sym) {
DEBUG.P(this,"writeMemberAttrs(Symbol sym)");
DEBUG.P("sym="+sym);
if(sym.type!=null) {
DEBUG.P("sym.type="+sym.type);
DEBUG.P("sym.erasure(types)="+sym.erasure(types));
DEBUG.P("sym.type.getThrownTypes()="+sym.type.getThrownTypes());
}
int acount = writeFlagAttrs(sym.flags());
long flags = sym.flags();
DEBUG.P("flags="+Flags.toString(flags));
if (source.allowGenerics() &&
(flags & (SYNTHETIC|BRIDGE)) != SYNTHETIC &&
(flags & ANONCONSTR) == 0 &&
(!types.isSameType(sym.type, sym.erasure(types)) ||
hasTypeVar(sym.type.getThrownTypes()))) {
// <editor-fold defaultstate="collapsed">
/*样例:private T t;
输出:
com.sun.tools.javac.jvm.ClassWriter===>writeMemberAttrs(Symbol sym)
-------------------------------------------------------------------------
sym=t
sym.type=T
sym.erasure(types)=java.lang.Object
sym.type.getThrownTypes()=
com.sun.tools.javac.jvm.ClassWriter===>writeFlagAttrs(long flags)
-------------------------------------------------------------------------
flags=0x2 private
acount=0
com.sun.tools.javac.jvm.ClassWriter===>writeFlagAttrs(long flags) END
-------------------------------------------------------------------------
flags=0x2 private
com.sun.tools.javac.jvm.ClassWriter===>writeAttr(Name attrName)
-------------------------------------------------------------------------
attrName=Signature
alenIdx=188
com.sun.tools.javac.jvm.ClassWriter===>writeAttr(Name attrName) END
-------------------------------------------------------------------------
*/
// </editor-fold>
// 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.getAnnotationMirrors());
DEBUG.P("acount="+acount);
DEBUG.P(0,this,"writeMemberAttrs(Symbol sym)");
return acount;
}
/** Write method parameter annotations;
* return number of attributes written.
*/
int writeParameterAttrs(MethodSymbol m) {
DEBUG.P(this,"writeParameterAttrs(1)");
DEBUG.P("m="+m);
boolean hasVisible = false;
boolean hasInvisible = false;
if (m.params != null) for (VarSymbol s : m.params) {
for (Attribute.Compound a : s.getAnnotationMirrors()) {
switch (getRetention(a.type.tsym)) {
case SOURCE: break;
case CLASS: hasInvisible = true; break;
case RUNTIME: hasVisible = true; break;
default: ;// /* fail soft */ throw new AssertionError(vis);
}
}
}
int attrCount = 0;
DEBUG.P("hasVisible="+hasVisible);
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.getAnnotationMirrors())
if (getRetention(a.type.tsym) == RetentionPolicy.RUNTIME)
buf.append(a);
databuf.appendChar(buf.length());
for (Attribute.Compound a : buf)
writeCompoundAttribute(a);
}
endAttr(attrIndex);
attrCount++;
}
DEBUG.P("attrCount="+attrCount);
DEBUG.P("hasInvisible="+hasInvisible);
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.getAnnotationMirrors())
if (getRetention(a.type.tsym) == RetentionPolicy.CLASS)
buf.append(a);
databuf.appendChar(buf.length());
for (Attribute.Compound a : buf)
writeCompoundAttribute(a);
}
endAttr(attrIndex);
attrCount++;
}
DEBUG.P("attrCount="+attrCount);
DEBUG.P(0,this,"writeParameterAttrs(1)");
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) {
try {//我加上的
DEBUG.P(this,"writeJavaAnnotations(1)");
DEBUG.P("attrs.isEmpty()="+attrs.isEmpty());
if (attrs.isEmpty()) return 0;
DEBUG.P("attrs="+attrs);
ListBuffer<Attribute.Compound> visibles = new ListBuffer<Attribute.Compound>();
ListBuffer<Attribute.Compound> invisibles = new ListBuffer<Attribute.Compound>();
for (Attribute.Compound a : attrs) {
switch (getRetention(a.type.tsym)) {
case SOURCE: break;
case CLASS: invisibles.append(a); break;
case RUNTIME: visibles.append(a); break;
default: ;// /* fail soft */ throw new AssertionError(vis);
}
}
DEBUG.P("visibles.length()="+visibles.length());
int attrCount = 0;
if (visibles.length() != 0) {
/*表示：
RuntimeVisibleAnnotations {
u2 attribute_name_index;
u4 attribute_length;
u2 annotations_count;
annotation_info annotations[annotations_count];
}
*/
int attrIndex = writeAttr(names.RuntimeVisibleAnnotations);
databuf.appendChar(visibles.length());
for (Attribute.Compound a : visibles)
writeCompoundAttribute(a);
endAttr(attrIndex);
attrCount++;
}
DEBUG.P("attrCount="+attrCount);
DEBUG.P("invisibles.length()="+invisibles.length());
if (invisibles.length() != 0) {
/*表示：
RuntimeInvisibleAnnotations {
u2 attribute_name_index;
u4 attribute_length;
u2 annotations_count;
annotation_info annotations[annotations_count];
}
*/
int attrIndex = writeAttr(names.RuntimeInvisibleAnnotations);
databuf.appendChar(invisibles.length());
for (Attribute.Compound a : invisibles)
writeCompoundAttribute(a);
endAttr(attrIndex);
attrCount++;
}
DEBUG.P("attrCount="+attrCount);
return attrCount;
}finally {//我加上的
DEBUG.P(0,this,"writeJavaAnnotations(1)");
}
}
/** A mirror of java.lang.annotation.RetentionPolicy. */
enum RetentionPolicy {
SOURCE,
CLASS,
RUNTIME
}
RetentionPolicy getRetention(TypeSymbol annotationType) {
DEBUG.P(this,"getRetention(1)");
DEBUG.P("annotationType="+annotationType);
RetentionPolicy vis = RetentionPolicy.CLASS; // the default
Attribute.Compound c = annotationType.attribute(syms.retentionType.tsym);
DEBUG.P("c="+c);
//当定义一个Annotation没有使用@Retention时c==null
if (c != null) {
Attribute value = c.member(names.value);
DEBUG.P("value="+value);
if (value != null && value instanceof Attribute.Enum) {
Name levelName = ((Attribute.Enum)value).value.name;
if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
else ;// /* fail soft */ throw new AssertionError(levelName);
}
}
DEBUG.P("vis="+vis);
DEBUG.P(0,this,"getRetention(1)");
return vis;
}
/** A visitor to write an attribute including its leading
* single-character marker.
*/
class AttributeWriter implements Attribute.Visitor {
public void visitConstant(Attribute.Constant _value) {
DEBUG.P(this,"visitConstant(1)");
DEBUG.P("_value="+_value);
DEBUG.P("_value.type.tag="+TypeTags.toString(_value.type.tag));
Object value = _value.value;
switch (_value.type.tag) {
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 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));
DEBUG.P(0,this,"visitConstant(1)");
}
public void visitEnum(Attribute.Enum e) {
DEBUG.P(this,"visitEnum(1)");
DEBUG.P("e.value="+e.value);
DEBUG.P("e.value.type="+e.value.type);
DEBUG.P("e.value.name="+e.value.name);
databuf.appendByte('e');
databuf.appendChar(pool.put(typeSig(e.value.type)));
databuf.appendChar(pool.put(e.value.name));
DEBUG.P(0,this,"visitEnum(1)");
}
public void visitClass(Attribute.Class clazz) {
DEBUG.P(this,"visitClass(1)");
databuf.appendByte('c');
databuf.appendChar(pool.put(typeSig(clazz.type)));
DEBUG.P(0,this,"visitClass(1)");
}
public void visitCompound(Attribute.Compound compound) {
DEBUG.P(this,"visitCompound(1)");
databuf.appendByte('@');
writeCompoundAttribute(compound);
DEBUG.P(0,this,"visitCompound(1)");
}
public void visitError(Attribute.Error x) {
throw new AssertionError(x);
}
public void visitArray(Attribute.Array array) {
DEBUG.P(this,"visitArray(1)");
databuf.appendByte('[');
databuf.appendChar(array.values.length);
for (Attribute a : array.values) {
a.accept(this);
}
DEBUG.P(0,this,"visitArray(1)");
}
}
AttributeWriter awriter = new AttributeWriter();
/** Write a compound attribute excluding the '@' marker. */
void writeCompoundAttribute(Attribute.Compound c) {
//Attribute.Compound代表使用Annotation的实例，如:@MyAnnotation(f3=20)
DEBUG.P(this,"writeCompoundAttribute(1)");
DEBUG.P("c="+c);
//u2 注释类型全限定名在常量池中的索引
//u2 注释类型字段个数
//接着是注释类型字段表(表长＝注释类型字段个数)
//注释类型字段表每个表项组成如下:
//u2 注释类型字段名称在在常量池中的索引
//u1 注释类型字段的种类（B代表boolean,s代表String,e代表Enum
//c代表Class,@代表字段还是注释类型，［代表数组
//具体看上面的visitXXX方法
databuf.appendChar(pool.put(typeSig(c.type)));
//c.values不包含未列出的Annotation字段，
//假设定义MyAnnotation时有f1,f2,f3，
//当使用这种形式时:@MyAnnotation(f3=20)
//c.values.length()=1
databuf.appendChar(c.values.length());
DEBUG.P("c.values="+c.values);
DEBUG.P("c.values.length()="+c.values.length());
for (Pair<Symbol.MethodSymbol,Attribute> p : c.values) {
DEBUG.P("p.fst.name="+p.fst.name);
DEBUG.P("p.snd.getClass().getName()="+p.snd.getClass().getName());
databuf.appendChar(pool.put(p.fst.name));
p.snd.accept(awriter);
}
DEBUG.P("databuf="+databuf);
DEBUG.P(0,this,"writeCompoundAttribute(1)");
}
/**********************************************************************
* Writing Objects
**********************************************************************/
/** Enter an inner class into the `innerClasses' set/queue.
*/
void enterInner(ClassSymbol c) {
try {//我加上的
DEBUG.P(this,"enterInner(1)");
DEBUG.P("c="+c);
DEBUG.P("innerClasses前="+innerClasses);
DEBUG.P("innerClassesQueue前="+innerClassesQueue);
assert !c.type.isCompound();
try {
c.complete();
} catch (CompletionFailure ex) {
System.err.println("error: " + c + ": " + ex.getMessage());
throw ex;
}
DEBUG.P("");
DEBUG.P("c.type="+c.type+" c.type.tag="+TypeTags.toString(c.type.tag));
DEBUG.P("pool="+pool);
if(pool != null) DEBUG.P("c.owner.kind="+Kinds.toString(c.owner.kind));
if (c.type.tag != CLASS) return; // arrays
if (pool != null && // pool might be null if called from xClassName
c.owner.kind != PCK &&
(innerClasses == null || !innerClasses.contains(c))) {
DEBUG.P("新增内部类");
// log.errWriter.println("enter inner " + c);//DEBUG
if (c.owner.kind == TYP) enterInner((ClassSymbol)c.owner);
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);
}
}finally{//我加上的
DEBUG.P("innerClasses后="+innerClasses);
DEBUG.P("innerClassesQueue后="+innerClassesQueue);
DEBUG.P(0,this,"enterInner(1)");
}
}
/** Write "inner classes" attribute.
*/
void writeInnerClasses() {
DEBUG.P(this,"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 (dumpInnerClassModifiers) {
log.errWriter.println("INNERCLASS " + inner.name);
log.errWriter.println("---" + flagNames(flags));
}
databuf.appendChar(pool.get(inner));
databuf.appendChar(
inner.owner.kind == TYP ? pool.get(inner.owner) : 0);
databuf.appendChar(
inner.name.len != 0 ? pool.get(inner.name) : 0);
databuf.appendChar(flags);
}
endAttr(alenIdx);
DEBUG.P(0,this,"writeInnerClasses()");
}
/** Write field symbol, entering all references into constant pool.
*/
void writeField(VarSymbol v) {
DEBUG.P(this,"writeField(VarSymbol v)");
DEBUG.P("v="+v);
DEBUG.P("v.flags()="+Flags.toString(v.flags()));
//注意在这里的字段access_flags就不像CClassFile中的access_flags,
//这里没有做更多限制
int flags = adjustFlags(v.flags());
DEBUG.P("flags="+Flags.toString(flags));
//DEBUG.P("v="+v+" flagNames="+flagNames(v.flags()));
/*对应:
field_info {
u2 access_flags;
u2 name_index;
u2 descriptor_index;
u2 attributes_count;
attribute_info attributes[attributes_count];
}*/
databuf.appendChar(flags);
if (dumpFieldModifiers) {
log.errWriter.println("FIELD " + fieldName(v));
log.errWriter.println("---" + flagNames(v.flags()));
}
databuf.appendChar(pool.put(fieldName(v)));
databuf.appendChar(pool.put(typeSig(v.erasure(types))));
int acountIdx = beginAttrs();
int acount = 0;
DEBUG.P("v.getConstValue()="+v.getConstValue());
//有STATIC FINAL标志的、且不在static初始块中赋值的字段才有“ConstantValue”属性
if (v.getConstValue() != null) {
int alenIdx = writeAttr(names.ConstantValue);
databuf.appendChar(pool.put(v.getConstValue()));
endAttr(alenIdx);
acount++;
}
acount += writeMemberAttrs(v);
endAttrs(acountIdx, acount);
DEBUG.P(0,this,"writeField(VarSymbol v)");
}
/** Write method symbol, entering all references into constant pool.
*/
void writeMethod(MethodSymbol m) {
DEBUG.P(this,"writeMethod(1)");
DEBUG.P("m="+m);
DEBUG.P("m.flags()="+Flags.toString(m.flags()));
int flags = adjustFlags(m.flags());
DEBUG.P("flags="+Flags.toString(flags));
//DEBUG.P("m="+m+" flagNames="+flagNames(m.flags()));
databuf.appendChar(flags);
if (dumpMethodModifiers) {
log.errWriter.println("METHOD " + fieldName(m));
log.errWriter.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();
DEBUG.P("thrown="+thrown);
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++;
}
DEBUG.P("m.defaultValue="+m.defaultValue);
if (m.defaultValue != null) {
int alenIdx = writeAttr(names.AnnotationDefault);
m.defaultValue.accept(awriter);
endAttr(alenIdx);
acount++;
}
acount += writeMemberAttrs(m);
acount += writeParameterAttrs(m);
endAttrs(acountIdx, acount);
DEBUG.P(0,this,"writeMethod(1)");
}
/** Write code attribute of method.
*/
void writeCode(Code code) {
DEBUG.P(this,"writeCode((1)");
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());
//code.catchInfo对应exception_info表
//每个char[]数组有四个元素:startPc, endPc, handlerPc, catchType
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());
//code.lineInfo对应line_number_info表
//每个char[]数组有两个元素:startPc, lineNumber
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++;
}
//"CharacterRangeTable"属性在
//“The JavaTM Virtual Machine Specification Second Edition”中未定义
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 var.start_pc >= 0;
assert var.start_pc <= code.cp;
databuf.appendChar(var.start_pc);
assert var.length >= 0;
assert (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);
//泛型本地变量的sym.type与vartype(擦除后的类型)是不同的
if (!types.isSameType(sym.type, vartype))
nGenericVars++;
databuf.appendChar(pool.put(typeSig(vartype)));
databuf.appendChar(var.reg);
}
endAttr(alenIdx);
acount++;
}
//"LocalVariableTypeTable"属性在
//“The JavaTM Virtual Machine Specification Second Edition”中未定义
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;
//泛型本地变量的sym.type与sym.erasure(types)是不同的
if (types.isSameType(sym.type, sym.erasure(types)))
continue;
count++;
// write variable info
databuf.appendChar(var.start_pc);
databuf.appendChar(var.length);
databuf.appendChar(pool.put(sym.name));
//注意这里和上面的区别，这里是使用未擦除的类型
databuf.appendChar(pool.put(typeSig(sym.type)));
databuf.appendChar(var.reg);
}
assert 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);
DEBUG.P(0,this,"writeCode((1)");
}
void writeStackMap(Code code) {
DEBUG.P(this,"writeStackMap((1)");
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 code.stackMapBuffer == null;
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");
}
DEBUG.P(0,this,"writeStackMap((1)");
}
//where
void writeStackMapType(Type t) {
if (t == null) {
if (debugstackmap) System.out.print("empty");
databuf.appendByte(0);
}
else switch(t.tag) {
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.tag < TypeTags.INT || t.tag == TypeTags.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.tag == UNINITIALIZED_THIS) {
return t2.tag == UNINITIALIZED_THIS;
} else if (t1.tag == UNINITIALIZED_OBJECT) {
if (t2.tag == UNINITIALIZED_OBJECT) {
return ((UninitializedType)t1).offset == ((UninitializedType)t2).offset;
} else {
return false;
}
} else if (t2.tag == UNINITIALIZED_THIS || t2.tag == 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) {
DEBUG.P(this,"writeFields(Scope.Entry e)");
// process them in reverse sibling order;
// i.e., process them in declaration order.
List<VarSymbol> vars = List.nil();
//按源码中声明字段的顺序组成一个新的List
for (Scope.Entry i = e; i != null; i = i.sibling) {
if (i.sym.kind == VAR) vars = vars.prepend((VarSymbol)i.sym);
}
DEBUG.P("vars="+vars);
while (vars.nonEmpty()) {
writeField(vars.head);
vars = vars.tail;
}
DEBUG.P(0,this,"writeFields(Scope.Entry e)");
}
void writeMethods(Scope.Entry e) {
DEBUG.P(this,"writeMethods(1)");
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);
}
DEBUG.P("methods="+methods);
while (methods.nonEmpty()) {
writeMethod(methods.head);
methods = methods.tail;
}
DEBUG.P(0,this,"writeMethods(1)");
}
/** 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
{
DEBUG.P(this,"writeClass(ClassSymbol c)");
DEBUG.P("c="+c);
DEBUG.P("c.sourcefile="+c.sourcefile);
JavaFileObject outFile
= fileManager.getJavaFileForOutput(CLASS_OUTPUT,
c.flatname.toString(),
JavaFileObject.Kind.CLASS,
c.sourcefile);
OutputStream out = outFile.openOutputStream();
DEBUG.P("outFile="+outFile);
try {
writeClassFile(out, c);
if (verbose)
log.errWriter.println(log.getLocalizedString("verbose.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;
}
}
DEBUG.P(0,this,"writeClass(ClassSymbol c)");
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 {
DEBUG.P(this,"writeClassFile(OutputStream out, ClassSymbol c)");
assert (c.flags() & COMPOUND) == 0;
databuf.reset();
poolbuf.reset();
sigbuf.reset();
pool = c.pool;
innerClasses = null;
innerClassesQueue = null;
Type supertype = types.supertype(c.type);
List<Type> interfaces = types.interfaces(c.type);
List<Type> typarams = c.type.getTypeArguments();
DEBUG.P("supertype="+supertype+" supertype.tag="+TypeTags.toString(supertype.tag));
DEBUG.P("interfaces="+interfaces);
DEBUG.P("typarams="+typarams);
int flags = adjustFlags(c.flags());
//ClassFile层次的access_flags没有PROTECTED
if ((flags & PROTECTED) != 0) flags |= PUBLIC;
flags = flags & ClassFlags & ~STRICTFP;
//注意这里与<<深入java虚拟机>>P125中的差别，这里说明了接口是不设ACC_SUPER的
if ((flags & INTERFACE) == 0) flags |= ACC_SUPER;
/*注意在Flags类中的如下定义
LocalClassFlags = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC,
ClassFlags = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION
*
* 在VM规范中ClassFile层次的access_flags为:
* ACC_PUBLIC ACC_FINAL ACC_SUPER ACC_INTERFACE ACC_ABSTRACT
*
* 进行“flags = flags & ClassFlags & ~STRICTFP;”后
* flags最多包含以下标志：(去掉了STRICTFP)
* FINAL | ABSTRACT | ENUM | SYNTHETIC ｜
* INTERFACE | PUBLIC | ANNOTATION
*
* 另外虽然VM规范中定义的标志以“ACC_”开头，但是实际的值跟Flags类中定义的值一样的，
* 只不过Flags类中用的是移位，VM规范中真接给出16进制值
* 如在Flags类中“FINAL = 1<<4”就对应VM规范中的“ACC_FINAL＝0x0010”
*/
if (dumpClassModifiers) {
log.errWriter.println();
log.errWriter.println("CLASSFILE " + c.getQualifiedName());
log.errWriter.println("---" + flagNames(flags));
}
DEBUG.P("flagNames="+flagNames(flags));
DEBUG.P("flags ="+Flags.toString(flags));
//参考<<深入java虚拟机>>P122
databuf.appendChar(flags);//指access_flags 占两字节
//指this_class,指向常量池索引，占两字节
databuf.appendChar(pool.put(c));
//指super_class,指向常量池索引或0，占两字节(只有c=java.lang.Object才为0)
databuf.appendChar(supertype.tag == CLASS ? pool.put(supertype.tsym) : 0);
//指interfaces_count,占两字节
databuf.appendChar(interfaces.length());
for (List<Type> l = interfaces; l.nonEmpty(); l = l.tail)
//指interfaces,指向常量池索引，占两字节
databuf.appendChar(pool.put(l.head.tsym));
int fieldsCount = 0;
int methodsCount = 0;
DEBUG.P("c.members()="+c.members());
for (Scope.Entry e = c.members().elems; e != null; e = e.sibling) {
switch (e.sym.kind) {
case VAR: fieldsCount++; break;
//HYPOTHETICAL看Flags中的注释
case MTH: if ((e.sym.flags() & HYPOTHETICAL) == 0) methodsCount++;
break;
case TYP: enterInner((ClassSymbol)e.sym); break;
default : assert false;
}
}
DEBUG.P("fieldsCount ="+fieldsCount);
DEBUG.P("methodsCount="+methodsCount);
//指fields_count,占两字节
databuf.appendChar(fieldsCount);
//指fields
writeFields(c.members().elems);
//指methods_count,占两字节
databuf.appendChar(methodsCount);
//指methods
writeMethods(c.members().elems);
int acountIdx = beginAttrs();
int acount = 0;
DEBUG.P("acountIdx="+acountIdx);
//是否是泛型类或泛型接口
boolean sigReq =
typarams.length() != 0 || supertype.getTypeArguments().length() != 0;
for (List<Type> l = interfaces; !sigReq && l.nonEmpty(); l = l.tail)
sigReq = l.head.getTypeArguments().length() != 0;
DEBUG.P("sigReq="+sigReq);
if (sigReq) {
DEBUG.P("sigbuf.toName(names)前="+sigbuf.toName(names));
assert source.allowGenerics();
//属性Signature的格式是:
//u2 字符串"Signature"在常量池中的索引
//u4 属性长度
//u2 属性值在常量池中的索引
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)));
DEBUG.P("sigbuf.toName(names)后="+sigbuf.toName(names));
sigbuf.reset();
endAttr(alenIdx);
acount++;
}
DEBUG.P("c.sourcefile="+c.sourcefile);
DEBUG.P("emitSourceFile="+emitSourceFile);
DEBUG.P("");
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 filename = c.sourcefile.toString();
DEBUG.P("filename="+filename);
int sepIdx = filename.lastIndexOf(File.separatorChar);
DEBUG.P("sepIdx="+sepIdx);
// Allow '/' as separator on all platforms, e.g., on Win32.
int slashIdx = filename.lastIndexOf('/');
DEBUG.P("slashIdx="+slashIdx);
if (slashIdx > sepIdx) sepIdx = slashIdx;
DEBUG.P("sepIdx="+sepIdx);
if (sepIdx >= 0) filename = filename.substring(sepIdx + 1);
DEBUG.P("filename="+filename);
databuf.appendChar(c.pool.put(names.fromString(filename)));
endAttr(alenIdx);
acount++;
}
DEBUG.P("genCrt="+genCrt);
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.getAnnotationMirrors());
acount += writeEnclosingMethodAttribute(c);
poolbuf.appendInt(JAVA_MAGIC);
poolbuf.appendChar(target.minorVersion);
poolbuf.appendChar(target.majorVersion);
writePool(c.pool);
if (innerClasses != null) {
writeInnerClasses();
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
DEBUG.P(0,this,"writeClassFile(OutputStream out, ClassSymbol c)");
}
int adjustFlags(final long flags) {
DEBUG.P(this,"adjustFlags(1)");
DEBUG.P("flags ="+Flags.toString(flags));
int result = (int)flags;//从32bit开始的标志位将被丢弃
//DEBUG.P("result ="+Flags.toString(result));
//DEBUG.P("result ="+Flags.toString(0xff));
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;
//DEBUG.P("result="+Flags.toString(result));
//当int的最高位是1时，转换成long时最高位1向左扩展32位
DEBUG.P("result="+Flags.toString((long)result&0x00000000ffffffff));
DEBUG.P(0,this,"adjustFlags(1)");
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;
}
}