classreader.java

这是实现Javac功能的GJC的最新源码

            throw badClassFile("unicode.str.not.supported");

        case CONSTANT_Class:
            poolObj[i] = readClassOrType(getChar(index + 1));
            break;

        case CONSTANT_String:
            poolObj[i] = readName(getChar(index + 1)).toString();
            break;

        case CONSTANT_Fieldref:
            {
                ClassSymbol owner = readClassSymbol(getChar(index + 1));
                NameAndType nt = (NameAndType) readPool(getChar(index + 3));
                poolObj[i] = new VarSymbol(0, nt.name, nt.type, owner);
                break;
            }

        case CONSTANT_Methodref:

        case CONSTANT_InterfaceMethodref:
            {
                ClassSymbol owner = readClassSymbol(getChar(index + 1));
                NameAndType nt = (NameAndType) readPool(getChar(index + 3));
                poolObj[i] = new MethodSymbol(0, nt.name, nt.type, owner);
                break;
            }

        case CONSTANT_NameandType:
            poolObj[i] = new NameAndType(readName(getChar(index + 1)),
                    readType(getChar(index + 3)));
            break;

        case CONSTANT_Integer:
            poolObj[i] = new Integer(getInt(index + 1));
            break;

        case CONSTANT_Float:
            poolObj[i] = new Float(getFloat(index + 1));
            break;

        case CONSTANT_Long:
            poolObj[i] = new Long(getLong(index + 1));
            break;

        case CONSTANT_Double:
            poolObj[i] = new Double(getDouble(index + 1));
            break;

        default:
            throw badClassFile("bad.const.pool.tag", Byte.toString(tag));

        }
        return poolObj[i];
    }

    /**
      * Read signature and convert to type.
      */
    Type readType(int i) {
        int index = poolIdx[i];
        return sigToType(buf, index + 3, getChar(index + 1));
    }

    /**
      * If name is an array type or class signature, return the
      *  corresponding type; otherwise return a ClassSymbol with given name.
      */
    Object readClassOrType(int i) {
        int index = poolIdx[i];
        int len = getChar(index + 1);
        int start = index + 3;
        return (buf[start] == '[' || buf[start + len - 1] == ';') ?
                (Object) sigToType(buf, start, len) :
                (Object) enterClass(names.fromUtf(internalize(buf, start, len)));
    }

    /**
      * Read class entry.
      */
    ClassSymbol readClassSymbol(int i) {
        return (ClassSymbol)(readPool(i));
    }

    /**
      * Read name.
      */
    Name readName(int i) {
        return (Name)(readPool(i));
    }

    /**
      * The unread portion of the currently read type is
      *  signature[sigp..siglimit-1].
      */
    byte[] signature;
    int sigp;
    int siglimit;
    boolean sigEnterPhase = false;

    /**
     * Convert signature to type, where signature is a name.
     */
    Type sigToType(Name sig) {
        return sig == null ? null : sigToType(sig.table.names, sig.index, sig.len);
    }

    /**
      * Convert signature to type, where signature is a byte array segment.
      */
    Type sigToType(byte[] sig, int offset, int len) {
        signature = sig;
        sigp = offset;
        siglimit = offset + len;
        return sigToType();
    }

    /**
      * Convert signature to type, where signature is implicit.
      */
    Type sigToType() {
        switch ((char) signature[sigp]) {
        case 'B':
            sigp++;
            return syms.byteType;

        case 'C':
            sigp++;
            return syms.charType;

        case 'D':
            sigp++;
            return syms.doubleType;

        case 'F':
            sigp++;
            return syms.floatType;

        case 'I':
            sigp++;
            return syms.intType;

        case 'J':
            sigp++;
            return syms.longType;

        case 'L':
            Type t = classSigToType(Type.noType);
            while (sigp < siglimit && signature[sigp] == '.') {
                sigp++;
                t = classSigToType(t);
            }
            return t;

        case 'S':
            sigp++;
            return syms.shortType;

        case 'V':
            sigp++;
            return syms.voidType;

        case 'Z':
            sigp++;
            return syms.booleanType;

        case '[':
            sigp++;
            while ('0' <= signature[sigp] && signature[sigp] <= '9')
                sigp++;
            return new ArrayType(sigToType(), syms.arrayClass);

        case '(':
            List argtypes = sigToTypes(')');
            Type restype = sigToType();
            ListBuffer thrown = new ListBuffer();
            while (signature[sigp] == '^') {
                sigp++;
                thrown.append(sigToType());
            }
            return new MethodType(argtypes, restype, thrown.toList(),
                    syms.methodClass);

        default:
            throw badClassFile("bad.signature",
                    Convert.utf2string(signature, sigp, 10));

        }
    }

    /**
      * Convert class signature to type, where signature is implicit.
      *  @param outer      The outer type encountered so far. This is meaningful
      *                    only if outer is parameterized. In that case we know
      *                    that we have to store it in the new type's
      *			  outer_field since a parameterized prefix is legal
      *			  only for non-static inner classes.
      */
    Type classSigToType(Type outer) {
        if (signature[sigp] == 'L') {
            sigp++;
            int start = sigp;
            while (signature[sigp] != ';' && signature[sigp] != '<')
                sigp++;
            ClassType t = (ClassType) enterClass(
                    names.fromUtf(internalize(signature, start, sigp - start))).type;
            if (signature[sigp] == '<')
                t = new ClassType(t.outer_field, sigToTypes('>'), t.tsym);
            else if (t.typarams().nonEmpty())
                t = (ClassType) t.erasure();
            if (outer.isParameterized())
                t = new ClassType(outer, t.typarams(), t.tsym);
            sigp++;
            return t;
        } else {
            throw badClassFile("bad.class.signature",
                    Convert.utf2string(signature, sigp, 10));
        }
    }

    /**
      * Convert (implicit) signature to list of types
      *  until `terminator' is encountered.
      */
    List sigToTypes(char terminator) {
        sigp++;
        ListBuffer types = new ListBuffer();
        while (signature[sigp] != terminator)
            types.append(sigToType());
        sigp++;
        return types.toList();
    }

    /**
      * Report unrecognized attribute.
      */
    void unrecogized(Name attrName) {
        if (checkClassFile)
            printCCF("ccf.unrecognized.attribute", attrName.toJava());
    }

    /**
      * Read member attribute.
      */
    void readMemberAttr(Symbol sym, Name attrName, int attrLen) {
        if (attrName == names.ConstantValue) {
            Object v = readPool(nextChar());
            if ((sym.flags() & FINAL) != 0)
                ((VarSymbol) sym).constValue = v;
        } else if (attrName == names.Code) {
            if (readAllOfClassFile)
                ((MethodSymbol) sym).code = readCode(sym);
            else
                bp = bp + attrLen;
        } else if (attrName == names.Exceptions) {
            int nexceptions = nextChar();
            ListBuffer thrown = new ListBuffer();
            for (int j = 0; j < nexceptions; j++)
                thrown.append(readClassSymbol(nextChar()).type);
            if (sym.type.thrown().isEmpty())
                sym.type.asMethodType().thrown = thrown.toList();
        } else if (attrName == names.Synthetic) {
            sym.flags_field |= SYNTHETIC;
        } else if (attrName == names.Deprecated) {
            sym.flags_field |= DEPRECATED;
        } else {
            unrecogized(attrName);
            bp = bp + attrLen;
        }
    }

    /**
      * Read member attributes.
      */
    void readMemberAttrs(Symbol sym) {
        char ac = nextChar();
        for (int i = 0; i < ac; i++) {
            Name attrName = readName(nextChar());
            int attrLen = nextInt();
            readMemberAttr(sym, attrName, attrLen);
        }
    }

    /**
      * Read class attribute.
      */
    void readClassAttr(ClassSymbol c, Name attrName, int attrLen) {
        if (attrName == names.SourceFile) {
            c.sourcefile = readName(nextChar());
        } else if (attrName == names.InnerClasses) {
            readInnerClasses(c);
        } else {
            readMemberAttr(c, attrName, attrLen);
        }
    }

    /**
      * Read class attributes.
      */
    void readClassAttrs(ClassSymbol c) {
        char ac = nextChar();
        for (int i = 0; i < ac; i++) {
            Name attrName = readName(nextChar());
            int attrLen = nextInt();
            readClassAttr(c, attrName, attrLen);
        }
    }

    /**
      * Read code block.
      */
    Code readCode(Symbol owner) {
        return null;
    }

    /**
      * Read a field.
      */
    VarSymbol readField() {
        int flags = nextChar();
        Name name = readName(nextChar());
        Type type = readType(nextChar());
        VarSymbol v = new VarSymbol(flags, name, type, currentOwner);
        readMemberAttrs(v);
        return v;
    }

    /**
      * Read a method.
      */
    MethodSymbol readMethod() {
        int flags = nextChar();
        Name name = readName(nextChar());
        Type type = readType(nextChar());
        if (name == names.init && currentOwner.hasOuterInstance()) {
            type = new MethodType(type.argtypes().tail, type.restype(),
                    type.thrown(), syms.methodClass);
        }
        MethodSymbol m = new MethodSymbol(flags, name, type, currentOwner);
        Symbol prevOwner = currentOwner;
        currentOwner = m;
        readMemberAttrs(m);
        currentOwner = prevOwner;
        return m;
    }

    /**
      * Skip a field or method
      */
    void skipMember() {
        bp = bp + 6;
        char ac = nextChar();
        for (int i = 0; i < ac; i++) {
            bp = bp + 2;
            int attrLen = nextInt();
            bp = bp + attrLen;
        }
    }

    /**
      * Enter type variables of this classtype and all enclosing ones in
      *  `typevars'.
      */
    void enterTypevars(Type t) {
        if (t.outer().tag == CLASS)
            enterTypevars(t.outer());
        for (List xs = t.typarams(); xs.nonEmpty(); xs = xs.tail)
            typevars.enter(((Type) xs.head).tsym);
    }

    /**
      * Read contents of a given class symbol `c'. Both external and internal
      *  versions of an inner class are read.
      */
    void readClass(ClassSymbol c) {
        ClassType ct = (ClassType) c.type;
        c.members_field = new Scope(c);
        typevars = typevars.dup();
        if (ct.outer().tag == CLASS)
            enterTypevars(ct.outer());
        int flags = nextChar();
        if (c.owner.kind == PCK)
            c.flags_field = flags;
        ClassSymbol self = readClassSymbol(nextChar());
        if (c != self)
            throw badClassFile("class.file.wrong.class", self.flatname.toJava());
        int startbp = bp;
        nextChar();
        char interfaceCount = nextChar();
        bp += interfaceCount * 2;
        char fieldCount = nextChar();
        for (int i = 0; i < fieldCount; i++)
            skipMember();
        char methodCount = nextChar();
        for (int i = 0; i < methodCount; i++)
            skipMember();
        readClassAttrs(c);
        if (readAllOfClassFile) {
            for (int i = 1; i < poolObj.length; i++)
                readPool(i);
            c.pool = new Pool(poolObj.length, poolObj);
        }
        bp = startbp;
        int n = nextChar();
        ct.supertype_field = (n == 0) ? Type.noType : readClassSymbol(n).type;
        n = nextChar();
        ListBuffer is = new ListBuffer();
        for (int i = 0; i < n; i++)
            is.append(readClassSymbol(nextChar()).type);
        ct.interfaces_field = is.toList();
        if (fieldCount != nextChar())
            assert false;
        for (int i = 0; i < fieldCount; i++)
            enterMember(c, readField());
        if (methodCount != nextChar())
            assert false;
        for (int i = 0; i < methodCount; i++)
            enterMember(c, readMethod());
        typevars = typevars.leave();
    }

    /**
      * Read inner class info. For each inner/outer pair allocate a
      *  member class.
      */
    void readInnerClasses(ClassSymbol c) {
        int n = nextChar();
        for (int i = 0; i < n; i++) {
            nextChar();
            ClassSymbol outer = readClassSymbol(nextChar());
            Name name = readName(nextChar());
            if (name == null)
                name = names.empty;
            int flags = nextChar();
            if (outer != null) {
                if (name == names.empty)
                    name = names.one;
                ClassSymbol member = enterClass(name, outer);
                if ((flags & STATIC) == 0) {
                    ((ClassType) member.type).outer_field = outer.type;
                }
                if (c == outer) {
                    member.flags_field = flags;
                    enterMember(c, member);
                }
            }
        }
    }

    /**
      * Read a class file.
      */
    void readClassFile(ClassSymbol c) throws IOException {
        int magic = nextInt();
        if (magic != JAVA_MAGIC)
            throw badClassFile("illegal.start.of.class.file");
        int minorVersion = nextChar();
        int majorVersion = nextChar();
        if (majorVersion > Target.MAX().majorVersion ||
                majorVersion * 1000 + minorVersion <
                Target.MIN().majorVersion * 1000 + Target.MIN().minorVersion) {
            throw badClassFile("wrong.version", Integer.toString(majorVersion),
                    Integer.toString(minorVersion),
                    Integer.toString(Target.MAX().majorVersion),
                    Integer.toString(Target.MAX().minorVersion));