8209003: Consolidate use of empty collections in java.lang.module
Reviewed-by: alanb, mchung
/*
* Copyright (c) 2014, 2018, 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 jdk.internal.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.InvalidModuleDescriptorException;
import java.lang.module.ModuleDescriptor;
import java.lang.module.ModuleDescriptor.Builder;
import java.lang.module.ModuleDescriptor.Requires;
import java.lang.module.ModuleDescriptor.Exports;
import java.lang.module.ModuleDescriptor.Opens;
import java.nio.ByteBuffer;
import java.nio.BufferUnderflowException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Supplier;
import jdk.internal.misc.JavaLangModuleAccess;
import jdk.internal.misc.SharedSecrets;
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.
*/
public final class ModuleInfo {
private final int JAVA_MIN_SUPPORTED_VERSION = 53;
private final int JAVA_MAX_SUPPORTED_VERSION = 56;
private static final JavaLangModuleAccess JLMA
= SharedSecrets.getJavaLangModuleAccess();
// supplies the set of packages when ModulePackages attribute not present
private final Supplier<Set<String>> packageFinder;
// indicates if the ModuleHashes attribute should be parsed
private final boolean parseHashes;
private ModuleInfo(Supplier<Set<String>> pf, boolean ph) {
packageFinder = pf;
parseHashes = ph;
}
private ModuleInfo(Supplier<Set<String>> pf) {
this(pf, true);
}
/**
* A holder class for the ModuleDescriptor that is created by reading the
* Module and other standard class file attributes. It also holds the objects
* that represent the non-standard class file attributes that are read from
* the class file.
*/
public static final class Attributes {
private final ModuleDescriptor descriptor;
private final ModuleTarget target;
private final ModuleHashes recordedHashes;
private final ModuleResolution moduleResolution;
Attributes(ModuleDescriptor descriptor,
ModuleTarget target,
ModuleHashes recordedHashes,
ModuleResolution moduleResolution) {
this.descriptor = descriptor;
this.target = target;
this.recordedHashes = recordedHashes;
this.moduleResolution = moduleResolution;
}
public ModuleDescriptor descriptor() {
return descriptor;
}
public ModuleTarget target() {
return target;
}
public ModuleHashes recordedHashes() {
return recordedHashes;
}
public ModuleResolution moduleResolution() {
return moduleResolution;
}
}
/**
* Reads a {@code module-info.class} from the given input stream.
*
* @throws InvalidModuleDescriptorException
* @throws IOException
*/
public static Attributes read(InputStream in, Supplier<Set<String>> pf)
throws IOException
{
try {
return new ModuleInfo(pf).doRead(new DataInputStream(in));
} catch (IllegalArgumentException | IllegalStateException e) {
throw invalidModuleDescriptor(e.getMessage());
} catch (EOFException x) {
throw truncatedModuleDescriptor();
}
}
/**
* Reads a {@code module-info.class} from the given byte buffer.
*
* @throws InvalidModuleDescriptorException
* @throws UncheckedIOException
*/
public static Attributes read(ByteBuffer bb, Supplier<Set<String>> pf) {
try {
return new ModuleInfo(pf).doRead(new DataInputWrapper(bb));
} catch (IllegalArgumentException | IllegalStateException e) {
throw invalidModuleDescriptor(e.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 ModuleHashes} attribute.
*
* @throws InvalidModuleDescriptorException
* @throws UncheckedIOException
*/
public static Attributes readIgnoringHashes(ByteBuffer bb, Supplier<Set<String>> pf) {
try {
return new ModuleInfo(pf, false).doRead(new DataInputWrapper(bb));
} catch (IllegalArgumentException | IllegalStateException e) {
throw invalidModuleDescriptor(e.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 Attributes 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 < JAVA_MIN_SUPPORTED_VERSION ||
major_version > JAVA_MAX_SUPPORTED_VERSION) {
throw invalidModuleDescriptor("Unsupported major.minor version "
+ major_version + "." + minor_version);
}
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);
if (!"module-info".equals(mn))
throw invalidModuleDescriptor("this_class should be module-info");
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<>();
Builder builder = null;
Set<String> allPackages = null;
String mainClass = null;
ModuleTarget moduleTarget = null;
ModuleHashes moduleHashes = null;
ModuleResolution moduleResolution = null;
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 :
builder = readModuleAttribute(in, cpool, major_version);
break;
case MODULE_PACKAGES :
allPackages = readModulePackagesAttribute(in, cpool);
break;
case MODULE_MAIN_CLASS :
mainClass = readModuleMainClassAttribute(in, cpool);
break;
case MODULE_TARGET :
moduleTarget = readModuleTargetAttribute(in, cpool);
break;
case MODULE_HASHES :
if (parseHashes) {
moduleHashes = readModuleHashesAttribute(in, cpool);
} else {
in.skipBytes(length);
}
break;
case MODULE_RESOLUTION :
moduleResolution = readModuleResolution(in, cpool);
break;
default:
if (isAttributeDisallowed(attribute_name)) {
throw invalidModuleDescriptor(attribute_name
+ " attribute not allowed");
} else {
in.skipBytes(length);
}
}
}
// the Module attribute is required
if (builder == null) {
throw invalidModuleDescriptor(MODULE + " attribute not found");
}
// ModuleMainClass attribute
if (mainClass != null) {
builder.mainClass(mainClass);
}
// If the ModulePackages attribute is not present then the packageFinder
// is used to find the set of packages
boolean usedPackageFinder = false;
if (allPackages == null && packageFinder != null) {
try {
allPackages = packageFinder.get();
} catch (UncheckedIOException x) {
throw x.getCause();
}
usedPackageFinder = true;
}
if (allPackages != null) {
Set<String> knownPackages = JLMA.packages(builder);
if (!allPackages.containsAll(knownPackages)) {
Set<String> missingPackages = new HashSet<>(knownPackages);
missingPackages.removeAll(allPackages);
assert !missingPackages.isEmpty();
String missingPackage = missingPackages.iterator().next();
String tail;
if (usedPackageFinder) {
tail = " not found in module";
} else {
tail = " missing from ModulePackages class file attribute";
}
throw invalidModuleDescriptor("Package " + missingPackage + tail);
}
builder.packages(allPackages);
}
ModuleDescriptor descriptor = builder.build();
return new Attributes(descriptor,
moduleTarget,
moduleHashes,
moduleResolution);
}
/**
* Reads the Module attribute, returning the ModuleDescriptor.Builder to
* build the corresponding ModuleDescriptor.
*/
private Builder readModuleAttribute(DataInput in, ConstantPool cpool, int major)
throws IOException
{
// module_name
int module_name_index = in.readUnsignedShort();
String mn = cpool.getModuleName(module_name_index);
int module_flags = in.readUnsignedShort();
Set<ModuleDescriptor.Modifier> modifiers = new HashSet<>();
boolean open = ((module_flags & ACC_OPEN) != 0);
if (open)
modifiers.add(ModuleDescriptor.Modifier.OPEN);
if ((module_flags & ACC_SYNTHETIC) != 0)
modifiers.add(ModuleDescriptor.Modifier.SYNTHETIC);
if ((module_flags & ACC_MANDATED) != 0)
modifiers.add(ModuleDescriptor.Modifier.MANDATED);
Builder builder = JLMA.newModuleBuilder(mn, false, modifiers);
int module_version_index = in.readUnsignedShort();
if (module_version_index != 0) {
String vs = cpool.getUtf8(module_version_index);
builder.version(vs);
}
int requires_count = in.readUnsignedShort();
boolean requiresJavaBase = false;
for (int i=0; i<requires_count; i++) {
int requires_index = in.readUnsignedShort();
String dn = cpool.getModuleName(requires_index);
int requires_flags = in.readUnsignedShort();
Set<Requires.Modifier> mods;
if (requires_flags == 0) {
mods = Set.of();
} else {
mods = new HashSet<>();
if ((requires_flags & ACC_TRANSITIVE) != 0)
mods.add(Requires.Modifier.TRANSITIVE);
if ((requires_flags & ACC_STATIC_PHASE) != 0)
mods.add(Requires.Modifier.STATIC);
if ((requires_flags & ACC_SYNTHETIC) != 0)
mods.add(Requires.Modifier.SYNTHETIC);
if ((requires_flags & ACC_MANDATED) != 0)
mods.add(Requires.Modifier.MANDATED);
}
int requires_version_index = in.readUnsignedShort();
if (requires_version_index == 0) {
builder.requires(mods, dn);
} else {
String vs = cpool.getUtf8(requires_version_index);
JLMA.requires(builder, mods, dn, vs);
}
if (dn.equals("java.base")) {
if (major >= 54
&& (mods.contains(Requires.Modifier.TRANSITIVE)
|| mods.contains(Requires.Modifier.STATIC))) {
String flagName;
if (mods.contains(Requires.Modifier.TRANSITIVE)) {
flagName = "ACC_TRANSITIVE";
} else {
flagName = "ACC_STATIC_PHASE";
}
throw invalidModuleDescriptor("The requires entry for java.base"
+ " has " + flagName + " set");
}
requiresJavaBase = true;
}
}
if (mn.equals("java.base")) {
if (requires_count > 0) {
throw invalidModuleDescriptor("The requires table for java.base"
+ " must be 0 length");
}
} else if (!requiresJavaBase) {
throw invalidModuleDescriptor("The requires table must have"
+ " an entry for java.base");
}
int exports_count = in.readUnsignedShort();
if (exports_count > 0) {
for (int i=0; i<exports_count; i++) {
int exports_index = in.readUnsignedShort();
String pkg = cpool.getPackageName(exports_index);
Set<Exports.Modifier> mods;
int exports_flags = in.readUnsignedShort();
if (exports_flags == 0) {
mods = Set.of();
} else {
mods = new HashSet<>();
if ((exports_flags & ACC_SYNTHETIC) != 0)
mods.add(Exports.Modifier.SYNTHETIC);
if ((exports_flags & ACC_MANDATED) != 0)
mods.add(Exports.Modifier.MANDATED);
}
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();
String target = cpool.getModuleName(exports_to_index);
if (!targets.add(target)) {
throw invalidModuleDescriptor(pkg + " exported to "
+ target + " more than once");
}
}
builder.exports(mods, pkg, targets);
} else {
builder.exports(mods, pkg);
}
}
}
int opens_count = in.readUnsignedShort();
if (opens_count > 0) {
if (open) {
throw invalidModuleDescriptor("The opens table for an open"
+ " module must be 0 length");
}
for (int i=0; i<opens_count; i++) {
int opens_index = in.readUnsignedShort();
String pkg = cpool.getPackageName(opens_index);
Set<Opens.Modifier> mods;
int opens_flags = in.readUnsignedShort();
if (opens_flags == 0) {
mods = Set.of();
} else {
mods = new HashSet<>();
if ((opens_flags & ACC_SYNTHETIC) != 0)
mods.add(Opens.Modifier.SYNTHETIC);
if ((opens_flags & ACC_MANDATED) != 0)
mods.add(Opens.Modifier.MANDATED);
}
int open_to_count = in.readUnsignedShort();
if (open_to_count > 0) {
Set<String> targets = new HashSet<>(open_to_count);
for (int j=0; j<open_to_count; j++) {
int opens_to_index = in.readUnsignedShort();
String target = cpool.getModuleName(opens_to_index);
if (!targets.add(target)) {
throw invalidModuleDescriptor(pkg + " opened to "
+ target + " more than once");
}
}
builder.opens(mods, pkg, targets);
} else {
builder.opens(mods, 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);
builder.uses(sn);
}
}
int provides_count = in.readUnsignedShort();
if (provides_count > 0) {
for (int i=0; i<provides_count; i++) {
int index = in.readUnsignedShort();
String sn = cpool.getClassName(index);
int with_count = in.readUnsignedShort();
List<String> providers = new ArrayList<>(with_count);
for (int j=0; j<with_count; j++) {
index = in.readUnsignedShort();
String pn = cpool.getClassName(index);
if (!providers.add(pn)) {
throw invalidModuleDescriptor(sn + " provides " + pn
+ " more than once");
}
}
builder.provides(sn, providers);
}
}
return builder;
}
/**
* Reads the ModulePackages attribute
*/
private Set<String> readModulePackagesAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int package_count = in.readUnsignedShort();
Set<String> packages = new HashSet<>(package_count);
for (int i=0; i<package_count; i++) {
int index = in.readUnsignedShort();
String pn = cpool.getPackageName(index);
boolean added = packages.add(pn);
if (!added) {
throw invalidModuleDescriptor("Package " + pn + " in ModulePackages"
+ "attribute more than once");
}
}
return packages;
}
/**
* Reads the ModuleMainClass attribute
*/
private String readModuleMainClassAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int index = in.readUnsignedShort();
return cpool.getClassName(index);
}
/**
* Reads the ModuleTarget attribute
*/
private ModuleTarget readModuleTargetAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
String targetPlatform = null;
int index = in.readUnsignedShort();
if (index != 0)
targetPlatform = cpool.getUtf8(index);
return new ModuleTarget(targetPlatform);
}
/**
* Reads the ModuleHashes attribute
*/
private ModuleHashes readModuleHashesAttribute(DataInput in, ConstantPool cpool)
throws IOException
{
int algorithm_index = in.readUnsignedShort();
String algorithm = cpool.getUtf8(algorithm_index);
int hash_count = in.readUnsignedShort();
Map<String, byte[]> map = new HashMap<>(hash_count);
for (int i=0; i<hash_count; i++) {
int module_name_index = in.readUnsignedShort();
String mn = cpool.getModuleName(module_name_index);
int hash_length = in.readUnsignedShort();
if (hash_length == 0) {
throw invalidModuleDescriptor("hash_length == 0");
}
byte[] hash = new byte[hash_length];
in.readFully(hash);
map.put(mn, hash);
}
return new ModuleHashes(algorithm, map);
}
/**
* Reads the ModuleResolution attribute.
*/
private ModuleResolution readModuleResolution(DataInput in,
ConstantPool cpool)
throws IOException
{
int flags = in.readUnsignedShort();
int reason = 0;
if ((flags & WARN_DEPRECATED) != 0)
reason = WARN_DEPRECATED;
if ((flags & WARN_DEPRECATED_FOR_REMOVAL) != 0) {
if (reason != 0)
throw invalidModuleDescriptor("Bad module resolution flags:" + flags);
reason = WARN_DEPRECATED_FOR_REMOVAL;
}
if ((flags & WARN_INCUBATING) != 0) {
if (reason != 0)
throw invalidModuleDescriptor("Bad module resolution flags:" + flags);
}
return new ModuleResolution(flags);
}
/**
* 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(MODULE_PACKAGES) ||
name.equals(MODULE_MAIN_CLASS) ||
name.equals(MODULE_TARGET) ||
name.equals(MODULE_HASHES) ||
name.equals(MODULE_RESOLUTION))
return true;
return false;
}
/**
* Return true if the given attribute name is the name of a pre-defined
* attribute in JVMS 4.7 that is not allowed in a module-info class.
*/
private static boolean isAttributeDisallowed(String name) {
Set<String> notAllowed = predefinedNotAllowed;
if (notAllowed == null) {
notAllowed = Set.of(
"ConstantValue",
"Code",
"Deprecated",
"StackMapTable",
"Exceptions",
"EnclosingMethod",
"Signature",
"LineNumberTable",
"LocalVariableTable",
"LocalVariableTypeTable",
"RuntimeVisibleParameterAnnotations",
"RuntimeInvisibleParameterAnnotations",
"RuntimeVisibleTypeAnnotations",
"RuntimeInvisibleTypeAnnotations",
"Synthetic",
"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;
static final int CONSTANT_Module = 19;
static final int CONSTANT_Package = 20;
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_Package:
case CONSTANT_Module:
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);
}
String value = getUtf8(((IndexEntry) e).index);
checkUnqualifiedName("CONSTANT_Class", index, value);
return value.replace('/', '.'); // internal form -> binary name
}
String getPackageName(int index) {
checkIndex(index);
Entry e = pool[index];
if (e.tag != CONSTANT_Package) {
throw invalidModuleDescriptor("CONSTANT_Package expected at entry: "
+ index);
}
String value = getUtf8(((IndexEntry) e).index);
checkUnqualifiedName("CONSTANT_Package", index, value);
return value.replace('/', '.'); // internal form -> binary name
}
String getModuleName(int index) {
checkIndex(index);
Entry e = pool[index];
if (e.tag != CONSTANT_Module) {
throw invalidModuleDescriptor("CONSTANT_Module expected at entry: "
+ index);
}
String value = getUtf8(((IndexEntry) e).index);
return decodeModuleName(index, value);
}
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");
}
void checkUnqualifiedName(String what, int index, String value) {
int len = value.length();
if (len == 0) {
throw invalidModuleDescriptor(what + " at entry " + index
+ " has zero length");
}
for (int i=0; i<len; i++) {
char c = value.charAt(i);
if (c == '.' || c == ';' || c == '[') {
throw invalidModuleDescriptor(what + " at entry " + index
+ " has illegal character: '"
+ c + "'");
}
}
}
/**
* "Decode" a module name that has been read from the constant pool.
*/
String decodeModuleName(int index, String value) {
int len = value.length();
if (len == 0) {
throw invalidModuleDescriptor("CONSTANT_Module at entry "
+ index + " is zero length");
}
int i = 0;
while (i < len) {
int cp = value.codePointAt(i);
if (cp == ':' || cp == '@' || cp < 0x20) {
throw invalidModuleDescriptor("CONSTANT_Module at entry "
+ index + " has illegal character: "
+ Character.getName(cp));
}
// blackslash is the escape character
if (cp == '\\')
return decodeModuleName(index, i, value);
i += Character.charCount(cp);
}
return value;
}
/**
* "Decode" a module name that has been read from the constant pool and
* partly checked for illegal characters (up to position {@code i}).
*/
String decodeModuleName(int index, int i, String value) {
StringBuilder sb = new StringBuilder();
// copy the code points that have been checked
int j = 0;
while (j < i) {
int cp = value.codePointAt(j);
sb.appendCodePoint(cp);
j += Character.charCount(cp);
}
// decode from position {@code i} to end
int len = value.length();
while (i < len) {
int cp = value.codePointAt(i);
if (cp == ':' || cp == '@' || cp < 0x20) {
throw invalidModuleDescriptor("CONSTANT_Module at entry "
+ index + " has illegal character: "
+ Character.getName(cp));
}
// blackslash is the escape character
if (cp == '\\') {
j = i + Character.charCount(cp);
if (j >= len) {
throw invalidModuleDescriptor("CONSTANT_Module at entry "
+ index + " has illegal "
+ "escape sequence");
}
int next = value.codePointAt(j);
if (next != '\\' && next != ':' && next != '@') {
throw invalidModuleDescriptor("CONSTANT_Module at entry "
+ index + " has illegal "
+ "escape sequence");
}
sb.appendCodePoint(next);
i += Character.charCount(next);
} else {
sb.appendCodePoint(cp);
}
i += Character.charCount(cp);
}
return sb.toString();
}
}
/**
* 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(e.getMessage());
}
}
@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(e.getMessage());
}
}
@Override
public byte readByte() throws IOException {
try {
return bb.get();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public int readUnsignedByte() throws IOException {
try {
return ((int) bb.get()) & 0xff;
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public short readShort() throws IOException {
try {
return bb.getShort();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public int readUnsignedShort() throws IOException {
try {
return ((int) bb.getShort()) & 0xffff;
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public char readChar() throws IOException {
try {
return bb.getChar();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public int readInt() throws IOException {
try {
return bb.getInt();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public long readLong() throws IOException {
try {
return bb.getLong();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public float readFloat() throws IOException {
try {
return bb.getFloat();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@Override
public double readDouble() throws IOException {
try {
return bb.getDouble();
} catch (BufferUnderflowException e) {
throw new EOFException(e.getMessage());
}
}
@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");
}
}