mockit.asm.ConstantPoolGeneration Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jmockit Show documentation
Show all versions of jmockit Show documentation
JMockit is a Java toolkit for automated developer testing.
It contains mocking/faking APIs and a code coverage tool, supporting both JUnit and TestNG.
The mocking APIs allow all kinds of Java code, without testability restrictions, to be tested
in isolation from selected dependencies.
package mockit.asm;
import javax.annotation.*;
import mockit.internal.util.*;
import static mockit.asm.Item.Type.*;
import static mockit.internal.util.ClassLoad.OBJECT;
/**
* Allows the constant pool for a classfile to be created from scratch, when that classfile itself is being generated or
* modified from an existing class file.
*/
final class ConstantPoolGeneration
{
/**
* The constant pool of the class file being generated/modified.
*/
@Nonnull private final ByteVector pool;
/**
* The constant pool's hash table data.
*/
@Nonnull private Item[] items;
/**
* The threshold of the constant pool's hash table.
*/
@Nonnegative private int threshold;
/**
* Index of the next item to be added in the constant pool.
*/
@Nonnegative private int index;
@Nonnull private final StringItem reusableUTF8Item;
@Nonnull private final StringItem reusableStringItem;
@Nonnull private final NameAndTypeItem reusableNameTypeItem;
@Nonnull private final ClassMemberItem reusableClassMemberItem;
@Nonnull private final IntItem reusableIntItem;
@Nonnull private final LongItem reusableLongItem;
@Nonnull private final FloatItem reusableFloatItem;
@Nonnull private final DoubleItem reusableDoubleItem;
@Nonnull private final MethodHandleItem reusableMethodHandleItem;
@Nonnull private final InvokeDynamicItem reusableInvokeDynamicItem;
/**
* A type table used to temporarily store internal names that will not necessarily be stored in the constant pool.
* This type table is used by the control flow and data flow analysis algorithm to compute stack map frames from
* scratch. This array associates to each index i the TypeTableItem whose index is i. All
* TypeTableItem objects stored in this array are also stored in the {@link #items} hash table. These two
* arrays allow to retrieve an Item from its index or, conversely, to get the index of an Item from
* its value. Each TypeTableItem stores an internal name in its {@link TypeTableItem#typeDesc} field.
*/
private TypeTableItem[] typeTable;
/**
* Number of elements in the {@link #typeTable} array.
*/
private short typeCount;
@Nonnull private final NormalTypeTableItem reusableNormalItem;
@Nonnull private final UninitializedTypeTableItem reusableUninitializedItem;
@Nonnull private final MergedTypeTableItem reusableMergedItem;
@SuppressWarnings("OverlyCoupledMethod")
ConstantPoolGeneration() {
pool = new ByteVector();
items = new Item[256];
threshold = (int) (0.75d * items.length);
index = 1;
reusableUTF8Item = new StringItem();
reusableStringItem = new StringItem();
reusableNameTypeItem = new NameAndTypeItem(0);
reusableClassMemberItem = new ClassMemberItem(0);
reusableIntItem = new IntItem(0);
reusableLongItem = new LongItem(0);
reusableFloatItem = new FloatItem(0);
reusableDoubleItem = new DoubleItem(0);
reusableMethodHandleItem = new MethodHandleItem(0);
reusableInvokeDynamicItem = new InvokeDynamicItem(0);
reusableNormalItem = new NormalTypeTableItem();
reusableUninitializedItem = new UninitializedTypeTableItem();
reusableMergedItem = new MergedTypeTableItem();
}
/**
* Adds an UTF8 string to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param value the String value.
* @return the index of a new or already existing UTF8 item.
*/
@Nonnegative
int newUTF8(@Nonnull String value) {
reusableUTF8Item.set(UTF8, value);
StringItem result = get(reusableUTF8Item);
if (result == null) {
pool.putByte(UTF8).putUTF8(value);
result = new StringItem(index++, reusableUTF8Item);
put(result);
}
return result.index;
}
/**
* Adds a class reference to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param internalName the internal name of the class.
* @return the index of a new or already existing class reference item.
*/
@Nonnegative
int newClass(@Nonnull String internalName) {
return newClassItem(internalName).index;
}
/**
* Adds a class reference to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param internalName the internal name of the class.
* @return a new or already existing class reference item.
*/
@Nonnull
StringItem newClassItem(@Nonnull String internalName) {
return newStringItem(CLASS, internalName);
}
/**
* Adds a string to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param type one of {@link Item.Type#STR}, {@link Item.Type#CLASS} or {@link Item.Type#MTYPE}
* @param value the String value.
* @return a new or already existing string item.
*/
@Nonnull
private StringItem newStringItem(int type, @Nonnull String value) {
reusableStringItem.set(type, value);
StringItem result = get(reusableStringItem);
if (result == null) {
int itemIndex = newUTF8(value);
pool.put12(type, itemIndex);
result = new StringItem(index++, reusableStringItem);
put(result);
}
return result;
}
/**
* Adds a method handle to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @return a new or an already existing method type reference item.
*/
@Nonnull
MethodHandleItem newMethodHandleItem(@Nonnull MethodHandle methodHandle) {
reusableMethodHandleItem.set(methodHandle);
MethodHandleItem result = get(reusableMethodHandleItem);
if (result == null) {
int tag = methodHandle.tag;
int memberType = tag == MethodHandle.Tag.INVOKEINTERFACE ? IMETH : METH;
ClassMemberItem memberItem =
newClassMemberItem(memberType, methodHandle.owner, methodHandle.name, methodHandle.desc);
pool.put11(HANDLE, tag).putShort(memberItem.index);
result = new MethodHandleItem(index++, reusableMethodHandleItem);
put(result);
}
return result;
}
@Nonnull
private ClassMemberItem newClassMemberItem(
int type, @Nonnull String owner, @Nonnull String name, @Nonnull String desc
) {
reusableClassMemberItem.set(type, owner, name, desc);
ClassMemberItem result = get(reusableClassMemberItem);
if (result == null) {
int ownerItemIndex = newClass(owner);
int nameAndTypeItemIndex = newNameType(name, desc);
put122(type, ownerItemIndex, nameAndTypeItemIndex);
result = new ClassMemberItem(index++, reusableClassMemberItem);
put(result);
}
return result;
}
/**
* Adds a field reference to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param owner the internal name of the field's owner class.
* @param name the field's name.
* @param desc the field's descriptor.
* @return a new or already existing field reference item.
*/
@Nonnull
ClassMemberItem newFieldItem(@Nonnull String owner, @Nonnull String name, @Nonnull String desc) {
return newClassMemberItem(FIELD, owner, name, desc);
}
/**
* Adds a method reference to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param owner the internal name of the method's owner class.
* @param name the method's name.
* @param desc the method's descriptor.
* @param itf true if owner is an interface.
* @return a new or already existing method reference item.
*/
@Nonnull
ClassMemberItem newMethodItem(@Nonnull String owner, @Nonnull String name, @Nonnull String desc, boolean itf) {
return newClassMemberItem(itf ? IMETH : METH, owner, name, desc);
}
/**
* Adds an integer to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param value the int value.
* @return a new or already existing int item.
*/
@Nonnull
IntItem newInteger(int value) {
reusableIntItem.setValue(value);
IntItem result = get(reusableIntItem);
if (result == null) {
pool.putByte(INT).putInt(value);
result = new IntItem(index++, reusableIntItem);
put(result);
}
return result;
}
/**
* Adds a float to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param value the float value.
* @return a new or already existing float item.
*/
@Nonnull
FloatItem newFloat(float value) {
reusableFloatItem.set(value);
FloatItem result = get(reusableFloatItem);
if (result == null) {
pool.putByte(FLOAT).putInt(reusableFloatItem.intVal);
result = new FloatItem(index++, reusableFloatItem);
put(result);
}
return result;
}
/**
* Adds a long to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param value the long value.
* @return a new or already existing long item.
*/
@Nonnull
LongItem newLong(long value) {
reusableLongItem.setValue(value);
LongItem result = get(reusableLongItem);
if (result == null) {
pool.putByte(LONG).putLong(value);
result = new LongItem(index, reusableLongItem);
index += 2;
put(result);
}
return result;
}
/**
* Adds a double to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param value the double value.
* @return a new or already existing double item.
*/
@Nonnull
DoubleItem newDouble(double value) {
reusableDoubleItem.set(value);
DoubleItem result = get(reusableDoubleItem);
if (result == null) {
pool.putByte(DOUBLE).putLong(reusableDoubleItem.longVal);
result = new DoubleItem(index, reusableDoubleItem);
index += 2;
put(result);
}
return result;
}
/**
* Adds a name and type to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param name a name.
* @param desc a type descriptor.
* @return the index of a new or already existing name and type item.
*/
int newNameType(@Nonnull String name, @Nonnull String desc) {
reusableNameTypeItem.set(name, desc);
NameAndTypeItem result = get(reusableNameTypeItem);
if (result == null) {
int nameItemIndex = newUTF8(name);
int descItemIndex = newUTF8(desc);
put122(NAME_TYPE, nameItemIndex, descItemIndex);
result = new NameAndTypeItem(index++, reusableNameTypeItem);
put(result);
}
return result.index;
}
/**
* Adds a number or string constant to the constant pool of the class being built.
* Does nothing if the constant pool already contains a similar item.
*
* @param cst the value of the constant to be added to the constant pool. This parameter must be an {@link Integer},
* a {@link Float}, a {@link Long}, a {@link Double}, a {@link String} or a {@link JavaType}.
* @return a new or already existing constant item with the given value.
*/
@Nonnull
Item newConstItem(@Nonnull Object cst) {
if (cst instanceof String) {
return newStringItem(STR, (String) cst);
}
if (cst instanceof Number) {
return newNumberItem((Number) cst);
}
if (cst instanceof Character) {
return newInteger((int) (Character) cst);
}
if (cst instanceof Boolean) {
int val = (Boolean) cst ? 1 : 0;
return newInteger(val);
}
if (cst instanceof ReferenceType) {
String typeDesc = ((ReferenceType) cst).getInternalName();
return cst instanceof MethodType ? newStringItem(MTYPE, typeDesc) : newClassItem(typeDesc);
}
if (cst instanceof PrimitiveType) {
String typeDesc = ((PrimitiveType) cst).getDescriptor();
return newClassItem(typeDesc);
}
if (cst instanceof MethodHandle) {
return newMethodHandleItem((MethodHandle) cst);
}
throw new IllegalArgumentException("value " + cst);
}
@Nonnull
private Item newNumberItem(Number cst) {
if (cst instanceof Float) {
return newFloat(cst.floatValue());
}
if (cst instanceof Long) {
return newLong(cst.longValue());
}
if (cst instanceof Double) {
return newDouble(cst.doubleValue());
}
return newInteger(cst.intValue());
}
/**
* Adds the given internal name to {@link #typeTable} and returns its index.
* Does nothing if the type table already contains this internal name.
*
* @param type the internal name to be added to the type table.
* @return the index of this internal name in the type table.
*/
int addNormalType(@Nonnull String type) {
reusableNormalItem.set(type);
TypeTableItem result = get(reusableNormalItem);
if (result == null) {
result = new NormalTypeTableItem(++typeCount, reusableNormalItem);
addToTypeTable(result);
}
return result.index;
}
/**
* Adds the given "uninitialized" type to {@link #typeTable} and returns its index.
* This method is used for UNINITIALIZED types, made of an internal name and a bytecode offset.
*
* @param type the internal name to be added to the type table.
* @param offset the bytecode offset of the NEW instruction that created this UNINITIALIZED type value.
* @return the index of this internal name in the type table.
*/
int addUninitializedType(@Nonnull String type, @Nonnegative int offset) {
reusableUninitializedItem.set(type, offset);
TypeTableItem result = get(reusableUninitializedItem);
if (result == null) {
result = new UninitializedTypeTableItem(++typeCount, reusableUninitializedItem);
addToTypeTable(result);
}
return result.index;
}
private void addToTypeTable(@Nonnull TypeTableItem newItem) {
put(newItem);
if (typeTable == null) {
typeTable = new TypeTableItem[16];
}
int newItemIndex = typeCount;
enlargeTypeTableIfNeeded(newItemIndex);
typeTable[newItemIndex] = newItem;
}
private void enlargeTypeTableIfNeeded(@Nonnegative int newItemIndex) {
int currentTypeCount = typeTable.length;
if (newItemIndex == currentTypeCount) {
TypeTableItem[] newTable = new TypeTableItem[2 * currentTypeCount];
System.arraycopy(typeTable, 0, newTable, 0, currentTypeCount);
typeTable = newTable;
}
}
/**
* Returns the index of the common super type of the two given types. This method calls {@link #getCommonSuperClass}
* and caches the result in the {@link #items} hash table to speedup future calls with the same parameters.
*
* @param type1 index of an internal name in {@link #typeTable}.
* @param type2 index of an internal name in {@link #typeTable}.
* @return the index of the common super type of the two given types.
*/
int getMergedType(@Nonnegative int type1, @Nonnegative int type2) {
reusableMergedItem.set(type1, type2);
MergedTypeTableItem result = get(reusableMergedItem);
if (result == null) {
String type1Desc = getInternalName(type1);
String type2Desc = getInternalName(type2);
String commonSuperClass = getCommonSuperClass(type1Desc, type2Desc);
reusableMergedItem.commonSuperTypeIndex = addNormalType(commonSuperClass);
result = new MergedTypeTableItem(reusableMergedItem);
put(result);
}
return result.commonSuperTypeIndex;
}
/**
* Returns the common super type of the two given types. The default implementation of this method loads the
* two given classes and uses the java.lang.Class methods to find the common super class. It can be overridden to
* compute this common super type in other ways, in particular without actually loading any class, or to take into
* account the class that is currently being generated by this ClassWriter, which can of course not be loaded since
* it is under construction.
*
* @param type1 the internal name of a class.
* @param type2 the internal name of another class.
* @return the internal name of the common super class of the two given classes.
*/
@Nonnull
private static String getCommonSuperClass(@Nonnull String type1, @Nonnull String type2) {
// Reimplemented to avoid "duplicate class definition" errors.
String class1 = type1;
String class2 = type2;
while (true) {
if (OBJECT.equals(class1) || OBJECT.equals(class2)) {
return OBJECT;
}
String superClass = ClassLoad.whichIsSuperClass(class1, class2);
if (superClass != null) {
return superClass;
}
class1 = ClassLoad.getSuperClass(class1);
class2 = ClassLoad.getSuperClass(class2);
if (class1.equals(class2)) {
return class1;
}
}
}
@Nonnull
String getInternalName(@Nonnegative int typeTableIndex) {
TypeTableItem typeTableItem = typeTable[typeTableIndex]; // Normal or Uninitialized
return typeTableItem.typeDesc;
}
@Nonnull
UninitializedTypeTableItem getUninitializedItemValue(@Nonnegative int typeTableIndex) {
return (UninitializedTypeTableItem) typeTable[typeTableIndex];
}
@Nullable
Item getItem(int itemHashCode) { return items[itemHashCode % items.length]; }
/**
* Returns the constant pool's hash table item which is equal to the given item.
*
* @param key a constant pool item.
* @return the constant pool's hash table item which is equal to the given item, or null if there is no
* such item.
*/
@Nullable
private I get(@Nonnull I key) {
Item item = getItem(key.hashCode);
int keyType = key.type;
while (item != null && (item.type != keyType || !key.isEqualTo(item))) {
item = item.next;
}
//noinspection unchecked
return (I) item;
}
/**
* Puts the given item in the constant pool's hash table. The hash table must not already contains this item.
*
* @param item the item to be added to the constant pool's hash table.
*/
void put(@Nonnull Item item) {
resizeItemArrayIfNeeded();
item.setNext(items);
}
private void resizeItemArrayIfNeeded() {
if (index + typeCount > threshold) {
int ll = items.length;
int nl = ll * 2 + 1;
Item[] newItems = new Item[nl];
for (int l = ll - 1; l >= 0; l--) {
Item j = items[l];
put(newItems, j);
}
items = newItems;
threshold = (int) (nl * 0.75);
}
}
private static void put(@Nonnull Item[] newItems, @Nullable Item item) {
while (item != null) {
Item k = item.next;
item.setNext(newItems);
item = k;
}
}
/**
* Puts one byte and two shorts into the constant pool.
*
* @param b a byte.
* @param s1 a short.
* @param s2 another short.
*/
private void put122(int b, int s1, int s2) {
pool.put12(b, s1).putShort(s2);
}
@Nonnegative
int getSize() { return pool.length; }
void checkConstantPoolMaxSize() {
if (index > 0xFFFF) {
throw new RuntimeException("Class file too large!");
}
}
void put(@Nonnull ByteVector out) {
out.putShort(index).putByteVector(pool);
}
void copy(@Nonnull byte[] code, @Nonnegative int off, @Nonnegative int header, @Nonnull Item[] items) {
pool.putByteArray(code, off, header - off);
this.items = items;
int ll = items.length;
threshold = (int) (0.75d * ll);
index = ll;
}
@Nonnull
InvokeDynamicItem createInvokeDynamicItem(@Nonnull String name, @Nonnull String desc, @Nonnegative int bsmIndex) {
reusableInvokeDynamicItem.set(name, desc, bsmIndex);
InvokeDynamicItem result = get(reusableInvokeDynamicItem);
if (result == null) {
int nameAndTypeItemIndex = newNameType(name, desc);
put122(INDY, bsmIndex, nameAndTypeItemIndex);
result = new InvokeDynamicItem(index++, reusableInvokeDynamicItem);
put(result);
}
return result;
}
}