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/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
\* */
// $Id$
package scalac.symtab.classfile;
import ch.epfl.lamp.util.Position;
import java.util.HashMap;
import java.io.*;
import scalac.Global;
import scalac.ApplicationError;
import scalac.util.*;
import scalac.symtab.*;
import Symbol.*;
import Type.*;
public class Pickle implements Kinds, Modifiers, EntryTags {
final static boolean debug = false;
/***************************************************
* Symbol table attribute format: see EntryTags.java
*/
public byte[] bytes;
private int bp;
private Name rootname;
private Symbol rootowner;
private HashMap index;
private Object[] entries;
private int ep;
/** Write symbol table info for root.
* root must be either a module or a class.
*/
public Pickle() {
index = new HashMap();
entries = new Object[256];
ep = 0;
}
/** Pickle all symbols descending from `root'.
*/
public void add(Symbol root) {
if (!root.isExternal()) {
if (Global.instance.debug) System.out.println("pickling " + root);
if (index.get(root) == null) {
this.rootname = root.name.toTermName();
this.rootowner = root.owner();
putSymbol(root);
}
}
}
/** Finalize pickler with given fullname.
*/
public void pickle() {
bytes = new byte[4096];
bp = 0;
writeAttr();
this.index = null;
this.entries = null;
}
/** The number of elements defined in `bytes'.
*/
public int size() {
return bp;
}
/* **************************************************
* Phase 1: Build entry table
************************************************* */
/** Is root in symbol.owner*?
*/
private boolean isLocal(Symbol sym) {
return
sym.name.toTermName() == rootname &&
sym.owner() == rootowner ||
(sym.kind != NONE && isLocal(sym.owner()));
}
/** Store entry `e' in index at next available position unless it it
* already there. Return true iff entry is new.
*/
private boolean putEntry(Object e) {
Integer n = (Integer) index.get(e);
if (n == null) {
//System.out.println("entry " + e);//DEBUG
if (ep == entries.length) {
Object[] entries1 = new Object[ep * 2];
System.arraycopy(entries, 0, entries1, 0, ep);
entries = entries1;
}
entries[ep] = e;
index.put(e, new Integer(ep));
ep++;
return true;
} else {
return false;
}
}
/** Store symbol in index. If symbol is local, also store
* everything it refers to.
*/
private void putSymbol(Symbol sym) {
if (putEntry(sym)) {
if (debug) System.out.println("put " + sym);
if (isLocal(sym)) {
putEntry(sym.name);
putSymbol(sym.owner());
putType(sym.info());
switch (sym.kind) {
case TYPE:
putType(sym.loBound());
break;
case ALIAS:
break;
case CLASS:
putType(sym.typeOfThis());
putSymbol(sym.allConstructors());
for (Scope.SymbolIterator it = sym.members().iterator();
it.hasNext();)
putSymbol(it.next());
break;
case VAL:
if (sym.isPrimaryConstructor())
putSymbol(sym.primaryConstructorClass());
else if (sym.isModule())
putSymbol(sym.moduleClass());
break;
default:
throw new ApplicationError();
}
} else if (sym.kind != NONE) {
putEntry(sym.isModuleClass() ? sym.name.toTermName() : sym.name);
if (sym.owner() != Global.instance.definitions.ROOT_CLASS)
putSymbol(sym.owner());
}
}
}
private void putSymbols(Symbol[] syms) {
for (int i = 0; i < syms.length; i++)
putSymbol(syms[i]);
}
/** Store type and everythig it refers to in index.
*/
private void putType(Type tp) {
if (putEntry(tp)) {
switch (tp) {
case NoType:
break;
case ThisType(Symbol sym):
putSymbol(sym);
break;
case SingleType(Type pre, Symbol sym):
putType(pre);
putSymbol(sym);
break;
case TypeRef(Type pre, Symbol sym, Type[] args):
putType(pre);
putSymbol(sym);
putTypes(args);
break;
case CompoundType(Type[] parents, Scope members):
putSymbol(tp.symbol());
putTypes(parents);
break;
case MethodType(Symbol[] vparams, Type result):
putType(result);
for (int i = 0; i < vparams.length; i++) {
Type ptype = vparams[i].type();
putType(ptype);
int pflags = vparams[i].flags;
if ((pflags & (COVARIANT | CONTRAVARIANT | REPEATED | DEF)) != 0)
putEntry(new FlagsAndType(encodeFlags(pflags), ptype));
}
break;
case PolyType(Symbol[] tparams, Type result):
putType(result);
putSymbols(tparams);
break;
case OverloadedType(Symbol[] alts, Type[] alttypes):
for (int i = 0; i < alts.length; i++) alts[i].flags |= ALTERNATIVE;
putSymbols(alts);
putTypes(alttypes);
break;
default:
throw new ApplicationError();
}
}
}
private void putTypes(Type[] tps) {
for (int i = 0; i < tps.length; i++)
putType(tps[i]);
}
/* **************************************************
* Phase 2: Write byte array
************************************************* */
private void resizeTo(int size) {
byte[] bytes1 = new byte[size];
System.arraycopy(bytes, 0, bytes1, 0, bp);
bytes = bytes1;
}
/** Write a byte of data
*/
private void writeByte(int b) {
if (bp == bytes.length) resizeTo(bytes.length * 2);
bytes[bp++] = (byte)b;
if (debug) System.out.print(b + " ");
}
/** Write a natural number in big endian format, base 128.
* All but the last digits have bit 0x80 set.
*/
private void writeNat(int x) {
int y = x >>> 7;
if (y != 0) writeNatPrefix(y);
writeByte(x & 0x7f);
}
private void writeNatPrefix(int x) {
int y = x >>> 7;
if (y != 0) writeNatPrefix(y);
writeByte((x & 0x7f) | 0x80);
}
/** Write a natural number at `pos'
* If number is more than one byte, shift rest of array to make space.
*/
private void patchNat(int pos, int x) {
bytes[pos] = (byte) (x & 0x7f);
int y = x >>> 7;
if (y != 0) patchNatPrefix(pos, y);
}
private void patchNatPrefix(int pos, int x) {
writeByte(0);
System.arraycopy(bytes, pos, bytes, pos+1, bp - (pos+1));
bytes[pos] = (byte) ((x & 0x7f) | 0x80);
int y = x >>> 7;
if (y != 0) patchNatPrefix(pos, y);
}
/** Write a reference to object, i.e., the object's number in the index.
*/
private void writeRef(Object ref) {
Integer i = (Integer) index.get(ref);
assert i != null : ref + " " + ref.getClass();
writeNat(i.intValue());
}
private void writeRefs(Object[] es) {
for (int i = 0; i < es.length; i++) writeRef(es[i]);
}
/** Write a name entry. Names are stored in Utf8 format.
*/
private void writeName(Name name) {
writeByte(name.isTermName() ? TERMname : TYPEname);
writeByte(0); // space for length
while (bp + name.length() > bytes.length) resizeTo(bytes.length * 2);
name.copyAscii(bytes, bp);
if (debug) System.out.print(name);
bp = bp + name.length();
}
/** Write a symbol entry.
*/
private void writeSymbol(Symbol sym) {
if (debug) System.out.println("write " + sym);
if (isLocal(sym)) {
switch (sym.kind) {
case TYPE:
writeByte(TYPEsym);
break;
case ALIAS:
writeByte(ALIASsym);
break;
case CLASS:
writeByte(CLASSsym);
break;
case VAL:
writeByte(VALsym);
break;
default:
throw new ApplicationError();
}
writeByte(0); // space for length
writeRef(sym.name);
writeRef(sym.owner());
writeNat(sym.flags);
writeRef(sym.info());
switch (sym.kind) {
case TYPE:
writeRef(sym.loBound());
break;
case ALIAS:
break;
case CLASS:
writeRef(sym.typeOfThis());
writeRef(sym.allConstructors());
break;
case VAL:
if (sym.isPrimaryConstructor())
writeRef(sym.primaryConstructorClass());
else if (sym.isModule())
writeRef(sym.moduleClass());
break;
}
} else if (sym.kind == NONE) {
writeByte(NONEsym);
writeByte(0); // space for length
} else {
if (sym.isModuleClass()) {
writeByte(EXTMODCLASSref);
writeByte(0); // space for length
writeRef(sym.name.toTermName());
} else {
writeByte(EXTref);
writeByte(0); // space for length
writeRef(sym.name);
}
if (sym.owner() != Global.instance.definitions.ROOT_CLASS)
writeRef(sym.owner());
}
sym.flags &= ~ALTERNATIVE;
}
/** Write a type entry.
*/
private void writeType(Type tp) {
switch (tp) {
case NoType:
writeByte(NOtpe);
writeByte(0); // space for length
break;
case ThisType(Symbol sym):
writeByte(THIStpe);
writeByte(0); // space for length
writeRef(sym);
break;
case SingleType(Type pre, Symbol sym):
writeByte(SINGLEtpe);
writeByte(0); // space for length
writeRef(pre);
writeRef(sym);
break;
case TypeRef(Type pre, Symbol sym, Type[] args):
writeByte(TYPEREFtpe);
writeByte(0); // space for length
writeRef(pre);
writeRef(sym);
writeRefs(args);
break;
case CompoundType(Type[] parents, Scope members):
writeByte(COMPOUNDtpe);
writeByte(0); // space for length
writeRef(tp.symbol());
writeRefs(parents);
break;
case MethodType(Symbol[] vparams, Type result):
writeByte(METHODtpe);
writeByte(0); // space for length
writeRef(result);
for (int i = 0; i < vparams.length; i++) {
Type ptype = vparams[i].type();
int pflags = vparams[i].flags;
if ((pflags & (COVARIANT | CONTRAVARIANT | REPEATED | DEF)) != 0)
writeRef(new FlagsAndType(encodeFlags(pflags), ptype));
else
writeRef(ptype);
}
break;
case PolyType(Symbol[] tparams, Type result):
writeByte(POLYtpe);
writeByte(0); // space for length
writeRef(result);
writeRefs(tparams);
break;
case OverloadedType(Symbol[] alts, Type[] alttypes):
writeByte(OVERLOADEDtpe);
writeByte(0); // space for length
writeRefs(alts);
writeRefs(alttypes);
break;
default:
throw new ApplicationError();
}
}
private void writeFlagsAndType(FlagsAndType ft) {
writeByte(FLAGGEDtpe);
writeByte(0); // space for length
writeNat(ft.flags);
writeRef(ft.type);
}
private void writeEntry(Object e) {
int startpos = bp;
if (e instanceof Symbol) writeSymbol((Symbol) e);
else if (e instanceof Type) writeType((Type) e);
else if (e instanceof Name) writeName((Name) e);
else if (e instanceof FlagsAndType) writeFlagsAndType((FlagsAndType) e);
else throw new ApplicationError();
patchNat(startpos + 1, bp - (startpos + 2));
}
private void writeAttr() {
writeNat(ep);
for (int i = 0; i < ep; i++) {
if (debug) System.out.print(i + "," + bp + ": ");
writeEntry(entries[i]);
if (debug) System.out.print("(" + entries[i] + ")");
if (debug) System.out.println();
}
}
private static int encodeFlags(int flags) {
int n = 0;
if ((flags & COVARIANT) != 0) n |= COVARflag;
if ((flags & CONTRAVARIANT) != 0) n |= CONTRAVARflag;
if ((flags & REPEATED) != 0) n |= REPEATEDflag;
if ((flags & DEF) != 0) n |= DEFflag;
return n;
}
static class FlagsAndType {
int flags;
Type type;
FlagsAndType(int flags, Type type) {
this.flags = flags;
this.type = type;
}
public boolean equals(Object other) {
if (other instanceof FlagsAndType) {
FlagsAndType that = (FlagsAndType) other;
return this.type.equals(that.type) &&
this.flags == that.flags;
} else {
return false;
}
}
public int hashCode() {
return 37 + ((flags * 41) ^ type.hashCode());
}
}
}
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