/*
* Copyright (c) 2014, 2015, 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 java.lang.module;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.UncheckedIOException;
import java.lang.module.ModuleDescriptor.Requires.Modifier;
import java.nio.ByteBuffer;
import java.nio.BufferUnderflowException;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.function.Supplier;
import jdk.internal.module.Hasher.DependencyHashes;
import static jdk.internal.module.ClassFileConstants.*;
/**
* Read module information from a {@code module-info} class file.
*
* @implNote The rationale for the hand-coded reader is startup performance
* and fine control over the throwing of InvalidModuleDescriptorException.
*/
final class ModuleInfo {
// supplies the set of packages when ConcealedPackages not present
private final Supplier<Set<String>> packageFinder;
// indicates if the Hashes attribute should be parsed
private final boolean parseHashes;
// the builder, created when parsing
private ModuleDescriptor.Builder builder;
private ModuleInfo(Supplier<Set<String>> pf, boolean ph) {
packageFinder = pf;
parseHashes = ph;
}
private ModuleInfo(Supplier<Set<String>> pf) {
this(pf, true);
}
/**
* Reads a {@code module-info.class} from the given input stream.
*
* @throws InvalidModuleDescriptorException
* @throws IOException
*/
public static ModuleDescriptor read(InputStream in,
Supplier<Set<String>> pf)
throws IOException
{
try {
return new ModuleInfo(pf).doRead(new DataInputStream(in));
} catch (IllegalArgumentException iae) {
// IllegalArgumentException means a malformed class
throw invalidModuleDescriptor(iae.getMessage());
} catch (EOFException x) {
throw truncatedModuleDescriptor();
}
}
/**
* Reads a {@code module-info.class} from the given byte buffer.
*
* @throws InvalidModuleDescriptorException
* @throws UncheckedIOException
*/
public static ModuleDescriptor read(ByteBuffer bb,
Supplier<Set<String>> pf)
{
try {
return new ModuleInfo(pf).doRead(new DataInputWrapper(bb));
} catch (IllegalArgumentException iae) {
// IllegalArgumentException means a malformed class
throw invalidModuleDescriptor(iae.getMessage());
} catch (EOFException x) {
throw truncatedModuleDescriptor();
} catch (IOException ioe) {
throw new UncheckedIOException(ioe);
}
}
/**
* Reads a {@code module-info.class} from the given byte buffer
* but ignore the {@code Hashes} attribute.
*
* @throws InvalidModuleDescriptorException
* @throws UncheckedIOException
*/
static ModuleDescriptor readIgnoringHashes(ByteBuffer bb,
Supplier<Set<String>> pf)
{
try {
return new ModuleInfo(pf, false).doRead(new DataInputWrapper(bb));
} catch (IllegalArgumentException iae) {
throw invalidModuleDescriptor(iae.getMessage());
} catch (EOFException x) {
throw truncatedModuleDescriptor();
} catch (IOException ioe) {
throw new UncheckedIOException(ioe);
}
}
/**
* Reads the input as a module-info class file.
*
* @throws IOException
* @throws InvalidModuleDescriptorException
* @throws IllegalArgumentException if thrown by the ModuleDescriptor.Builder
* because an identifier is not a legal Java identifier, duplicate
* exports, and many other reasons
*/
private ModuleDescriptor doRead(DataInput in) throws IOException {
int magic = in.readInt();
if (magic != 0xCAFEBABE)
throw invalidModuleDescriptor("Bad magic number");
int minor_version = in.readUnsignedShort();
int major_version = in.readUnsignedShort();
if (major_version < 53) {
// throw invalidModuleDescriptor"Must be >= 53.0");
}
ConstantPool cpool = new ConstantPool(in);
int access_flags = in.readUnsignedShort();
if (access_flags != ACC_MODULE)
throw invalidModuleDescriptor("access_flags should be ACC_MODULE");
int this_class = in.readUnsignedShort();
String mn = cpool.getClassName(this_class);
int suffix = mn.indexOf("/module-info");
if (suffix < 1)
throw invalidModuleDescriptor("this_class not of form name/module-info");
mn = mn.substring(0, suffix).replace('/', '.');
builder = new ModuleDescriptor.Builder(mn);
int super_class = in.readUnsignedShort();
if (super_class > 0)
throw invalidModuleDescriptor("bad #super_class");
int interfaces_count = in.readUnsignedShort();
if (interfaces_count > 0)
throw invalidModuleDescriptor("Bad #interfaces");
int fields_count = in.readUnsignedShort();
if (fields_count > 0)
throw invalidModuleDescriptor("Bad #fields");
int methods_count = in.readUnsignedShort();
if (methods_count > 0)
throw invalidModuleDescriptor("Bad #methods");
int attributes_count = in.readUnsignedShort();
// the names of the attributes found in the class file
Set<String> attributes = new HashSet<>();
for (int i = 0; i < attributes_count ; i++) {
int name_index = in.readUnsignedShort();
String attribute_name = cpool.getUtf8(name_index);
int length = in.readInt();
boolean added = attributes.add(attribute_name);
if (!added && isAttributeAtMostOnce(attribute_name)) {
throw invalidModuleDescriptor("More than one "
+ attribute_name + " attribute");
}
switch (attribute_name) {
case MODULE :
readModuleAttribute(mn, in, cpool);
break;
case CONCEALED_PACKAGES :
readConcealedPackagesAttribute(in, cpool);
break;
case VERSION :
readVersionAttribute(in, cpool);
break;
case MAIN_CLASS :
readMainClassAttribute(in, cpool);
break;
case TARGET_PLATFORM :
readTargetPlatformAttribute(in, cpool);
break;
case HASHES :
if (parseHashes) {
readHashesAttribute(in, cpool);
} else {
in.skipBytes(length);
}
break;
default:
if (isAttributeDisallowed(attribute_name)) {
throw invalidModuleDescriptor(attribute_name
+ " attribute not allowed");
} else {
in.skipBytes(length);
}
}
}
// the Module attribute is required
if (!attributes.contains(MODULE)) {
throw invalidModuleDescriptor(MODULE + " attribute not found");
}
// If the ConcealedPackages attribute is not present then the
// packageFinder is used to to find any non-exported packages.
if (!attributes.contains(CONCEALED_PACKAGES) && packageFinder != null) {
Set<String> pkgs;
try {
pkgs = new HashSet<>(packageFinder.get());
} catch (UncheckedIOException x) {
throw x.getCause();
}
pkgs.removeAll(builder.exportedPackages());
builder.conceals(pkgs);
}
// Was the Synthetic attribute present?
if (attributes.contains(SYNTHETIC))
builder.synthetic(true);
return builder.build();
}
/**
* Reads the Module attribute.
*/
private void readModuleAttribute(String mn, DataInput in, ConstantPool cpool)
throws IOException
{
int requires_count = in.readUnsignedShort();
if (requires_count == 0 && !mn.equals("java.base")) {
throw invalidModuleDescriptor("The requires table must have"
+ " at least one entry");
}
for (int i=0; i<requires_count; i++) {
int index = in.readUnsignedShort();
int flags = in.readUnsignedShort();
String dn = cpool.getUtf8(index);
Set<Modifier> mods;
if (flags == 0) {
mods = Collections.emptySet();
} else {
mods = new HashSet<>();
if ((flags & ACC_PUBLIC) != 0)
mods.add(Modifier.PUBLIC);
if ((flags & ACC_SYNTHETIC) != 0)
mods.add(Modifier.SYNTHETIC);
if ((flags & ACC_MANDATED) != 0)
mods.add(Modifier.MANDATED);
}
builder.requires(mods, dn);
}
int exports_count = in.readUnsignedShort();
if (exports_count > 0) {
for (int i=0; i<exports_count; i++) {
int index = in.readUnsignedShort();
String pkg = cpool.getUtf8(index).replace('/', '.');
int exports_to_count = in.readUnsignedShort();
if (exports_to_count > 0) {
Set<String> targets = new HashSet<>(exports_to_count);
for (int j=0; j<exports_to_count; j++) {
int exports_to_index = in.readUnsignedShort();
targets.add(cpool.getUtf8(exports_to_index));
}
builder.exports(pkg, targets);
} else {
builder.exports(pkg);
}
}
}
int uses_count = in.readUnsignedShort();
if (uses_count > 0) {
for (int i=0; i<uses_count; i++) {
int index = in.readUnsignedShort();
String sn = cpool.getClassName(index).replace('/', '.');
builder.uses(sn);
}
}
int provides_count = in.readUnsignedShort();
if (provides_count > 0) {
Map<String, Set<String>> pm = new HashMap<>();
for (int i=0; i<provides_count; i++) {
int index = in.readUnsignedShort();
int with_index = in.readUnsignedShort();
String sn = cpool.getClassName(index).replace('/', '.');
String cn = cpool.getClassName(with_index).replace('/', '.');
// computeIfAbsent
Set<String> providers = pm.get(sn);
if (providers == null) {
providers = new HashSet<>();
pm.put(sn, providers);
}
providers.add(cn);
}
for (Map.Entry<String, Set<String>> e : pm.entrySet()) {
builder.provides(e.getKey(), e.getValue());
}
}
}
/**
* Reads the ConcealedPackages attribute
*/
private void readConcealedPackagesAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int package_count = in.readUnsignedShort();
for (int i=0; i<package_count; i++) {
int index = in.readUnsignedShort();
String pn = cpool.getUtf8(index).replace('/', '.');
builder.conceals(pn);
}
}
/**
* Reads the Version attribute
*/
private void readVersionAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int index = in.readUnsignedShort();
builder.version(cpool.getUtf8(index));
}
/**
* Reads the MainClass attribute
*/
private void readMainClassAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int index = in.readUnsignedShort();
builder.mainClass(cpool.getClassName(index).replace('/', '.'));
}
/**
* Reads the TargetPlatform attribute
*/
private void readTargetPlatformAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int name_index = in.readUnsignedShort();
if (name_index != 0)
builder.osName(cpool.getUtf8(name_index));
int arch_index = in.readUnsignedShort();
if (arch_index != 0)
builder.osArch(cpool.getUtf8(arch_index));
int version_index = in.readUnsignedShort();
if (version_index != 0)
builder.osVersion(cpool.getUtf8(version_index));
}
/**
* Reads the Hashes attribute
*
* @apiNote For now the hash is stored in base64 as a UTF-8 string, this
* should be changed to be an array of u1.
*/
private void readHashesAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int index = in.readUnsignedShort();
String algorithm = cpool.getUtf8(index);
int hash_count = in.readUnsignedShort();
Map<String, String> map = new HashMap<>(hash_count);
for (int i=0; i<hash_count; i++) {
index = in.readUnsignedShort();
String dn = cpool.getUtf8(index);
index = in.readUnsignedShort();
String hash = cpool.getUtf8(index);
map.put(dn, hash);
}
builder.hashes(new DependencyHashes(algorithm, map));
}
/**
* Returns true if the given attribute can be present at most once
* in the class file. Returns false otherwise.
*/
private static boolean isAttributeAtMostOnce(String name) {
if (name.equals(MODULE) ||
name.equals(SOURCE_FILE) ||
name.equals(SDE) ||
name.equals(CONCEALED_PACKAGES) ||
name.equals(VERSION) ||
name.equals(MAIN_CLASS) ||
name.equals(TARGET_PLATFORM) ||
name.equals(HASHES))
return true;
return false;
}
/**
* Return true if the given attribute name is the name of a pre-defined
* attribute that is not allowed in the class file.
*
* Except for Module, InnerClasses, Synthetic, SourceFile, SourceDebugExtension,
* and Deprecated, none of the pre-defined attributes in JVMS 4.7 may appear.
*/
private static boolean isAttributeDisallowed(String name) {
Set<String> notAllowed = predefinedNotAllowed;
if (notAllowed == null) {
notAllowed = Set.of(
"ConstantValue",
"Code",
"StackMapTable",
"Exceptions",
"EnclosingMethod",
"Signature",
"LineNumberTable",
"LocalVariableTable",
"LocalVariableTypeTable",
"RuntimeVisibleAnnotations",
"RuntimeInvisibleAnnotations",
"RuntimeVisibleParameterAnnotations",
"RuntimeInvisibleParameterAnnotations",
"RuntimeVisibleTypeAnnotations",
"RuntimeInvisibleTypeAnnotations",
"AnnotationDefault",
"BootstrapMethods",
"MethodParameters");
predefinedNotAllowed = notAllowed;
}
return notAllowed.contains(name);
}
// lazily created set the pre-defined attributes that are not allowed
private static volatile Set<String> predefinedNotAllowed;
/**
* The constant pool in a class file.
*/
private static class ConstantPool {
static final int CONSTANT_Utf8 = 1;
static final int CONSTANT_Integer = 3;
static final int CONSTANT_Float = 4;
static final int CONSTANT_Long = 5;
static final int CONSTANT_Double = 6;
static final int CONSTANT_Class = 7;
static final int CONSTANT_String = 8;
static final int CONSTANT_Fieldref = 9;
static final int CONSTANT_Methodref = 10;
static final int CONSTANT_InterfaceMethodref = 11;
static final int CONSTANT_NameAndType = 12;
static final int CONSTANT_MethodHandle = 15;
static final int CONSTANT_MethodType = 16;
static final int CONSTANT_InvokeDynamic = 18;
private static class Entry {
protected Entry(int tag) {
this.tag = tag;
}
final int tag;
}
private static class IndexEntry extends Entry {
IndexEntry(int tag, int index) {
super(tag);
this.index = index;
}
final int index;
}
private static class Index2Entry extends Entry {
Index2Entry(int tag, int index1, int index2) {
super(tag);
this.index1 = index1;
this.index2 = index2;
}
final int index1, index2;
}
private static class ValueEntry extends Entry {
ValueEntry(int tag, Object value) {
super(tag);
this.value = value;
}
final Object value;
}
final Entry[] pool;
ConstantPool(DataInput in) throws IOException {
int count = in.readUnsignedShort();
pool = new Entry[count];
for (int i = 1; i < count; i++) {
int tag = in.readUnsignedByte();
switch (tag) {
case CONSTANT_Utf8:
String svalue = in.readUTF();
pool[i] = new ValueEntry(tag, svalue);
break;
case CONSTANT_Class:
case CONSTANT_String:
int index = in.readUnsignedShort();
pool[i] = new IndexEntry(tag, index);
break;
case CONSTANT_Double:
double dvalue = in.readDouble();
pool[i] = new ValueEntry(tag, dvalue);
i++;
break;
case CONSTANT_Fieldref:
case CONSTANT_InterfaceMethodref:
case CONSTANT_Methodref:
case CONSTANT_InvokeDynamic:
case CONSTANT_NameAndType:
int index1 = in.readUnsignedShort();
int index2 = in.readUnsignedShort();
pool[i] = new Index2Entry(tag, index1, index2);
break;
case CONSTANT_MethodHandle:
int refKind = in.readUnsignedByte();
index = in.readUnsignedShort();
pool[i] = new Index2Entry(tag, refKind, index);
break;
case CONSTANT_MethodType:
index = in.readUnsignedShort();
pool[i] = new IndexEntry(tag, index);
break;
case CONSTANT_Float:
float fvalue = in.readFloat();
pool[i] = new ValueEntry(tag, fvalue);
break;
case CONSTANT_Integer:
int ivalue = in.readInt();
pool[i] = new ValueEntry(tag, ivalue);
break;
case CONSTANT_Long:
long lvalue = in.readLong();
pool[i] = new ValueEntry(tag, lvalue);
i++;
break;
default:
throw invalidModuleDescriptor("Bad constant pool entry: "
+ i);
}
}
}
String getClassName(int index) {
checkIndex(index);
Entry e = pool[index];
if (e.tag != CONSTANT_Class) {
throw invalidModuleDescriptor("CONSTANT_Class expected at entry: "
+ index);
}
return getUtf8(((IndexEntry) e).index);
}
String getUtf8(int index) {
checkIndex(index);
Entry e = pool[index];
if (e.tag != CONSTANT_Utf8) {
throw invalidModuleDescriptor("CONSTANT_Utf8 expected at entry: "
+ index);
}
return (String) (((ValueEntry) e).value);
}
void checkIndex(int index) {
if (index < 1 || index >= pool.length)
throw invalidModuleDescriptor("Index into constant pool out of range");
}
}
/**
* A DataInput implementation that reads from a ByteBuffer.
*/
private static class DataInputWrapper implements DataInput {
private final ByteBuffer bb;
DataInputWrapper(ByteBuffer bb) {
this.bb = bb;
}
@Override
public void readFully(byte b[]) throws IOException {
readFully(b, 0, b.length);
}
@Override
public void readFully(byte b[], int off, int len) throws IOException {
try {
bb.get(b, off, len);
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public int skipBytes(int n) {
int skip = Math.min(n, bb.remaining());
bb.position(bb.position() + skip);
return skip;
}
@Override
public boolean readBoolean() throws IOException {
try {
int ch = bb.get();
return (ch != 0);
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public byte readByte() throws IOException {
try {
return bb.get();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public int readUnsignedByte() throws IOException {
try {
return ((int) bb.get()) & 0xff;
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public short readShort() throws IOException {
try {
return bb.getShort();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public int readUnsignedShort() throws IOException {
try {
return ((int) bb.getShort()) & 0xffff;
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public char readChar() throws IOException {
try {
return bb.getChar();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public int readInt() throws IOException {
try {
return bb.getInt();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public long readLong() throws IOException {
try {
return bb.getLong();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public float readFloat() throws IOException {
try {
return bb.getFloat();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public double readDouble() throws IOException {
try {
return bb.getDouble();
} catch (BufferUnderflowException e) {
throw new EOFException();
}
}
@Override
public String readLine() {
throw new RuntimeException("not implemented");
}
@Override
public String readUTF() throws IOException {
// ### Need to measure the performance and feasibility of using
// the UTF-8 decoder instead.
return DataInputStream.readUTF(this);
}
}
/**
* Returns an InvalidModuleDescriptorException with the given detail
* message
*/
private static InvalidModuleDescriptorException
invalidModuleDescriptor(String msg) {
return new InvalidModuleDescriptorException(msg);
}
/**
* Returns an InvalidModuleDescriptorException with a detail message to
* indicate that the class file is truncated.
*/
private static InvalidModuleDescriptorException truncatedModuleDescriptor() {
return invalidModuleDescriptor("Truncated module-info.class");
}
}