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*
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package sun.jvm.hotspot.interpreter;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.utilities.*;
public class BytecodeLoadConstant extends Bytecode {
BytecodeLoadConstant(Method method, int bci) {
super(method, bci);
}
public boolean hasCacheIndex() {
// normal ldc uses CP index, but fast_aldc uses swapped CP cache index
return code() >= Bytecodes.number_of_java_codes;
}
int rawIndex() {
if (javaCode() == Bytecodes._ldc)
return getIndexU1();
else
return getIndexU2(code(), false);
}
public int poolIndex() {
int index = rawIndex();
if (hasCacheIndex()) {
return method().getConstants().objectToCPIndex(index);
} else {
return index;
}
}
public int cacheIndex() {
if (hasCacheIndex()) {
return rawIndex();
} else {
return -1; // no cache index
}
}
public BasicType resultType() {
int index = poolIndex();
ConstantTag tag = method().getConstants().getTagAt(index);
return tag.basicType();
}
private Oop getCachedConstant() {
int i = cacheIndex();
if (i >= 0) {
throw new InternalError("invokedynamic not implemented yet");
}
return null;
}
public void verify() {
if (Assert.ASSERTS_ENABLED) {
Assert.that(isValid(), "check load constant");
}
}
public boolean isValid() {
int jcode = javaCode();
boolean codeOk = jcode == Bytecodes._ldc || jcode == Bytecodes._ldc_w ||
jcode == Bytecodes._ldc2_w;
if (! codeOk) return false;
ConstantTag ctag = method().getConstants().getTagAt(poolIndex());
if (jcode == Bytecodes._ldc2_w) {
// has to be double or long
return (ctag.isDouble() || ctag.isLong()) ? true: false;
} else {
// has to be int or float or String or Klass
return (ctag.isString()
|| ctag.isUnresolvedKlass() || ctag.isKlass()
|| ctag.isMethodHandle() || ctag.isMethodType()
|| ctag.isInt() || ctag.isFloat())? true: false;
}
}
public boolean isKlassConstant() {
int jcode = javaCode();
if (jcode == Bytecodes._ldc2_w) {
return false;
}
ConstantTag ctag = method().getConstants().getTagAt(poolIndex());
return ctag.isKlass() || ctag.isUnresolvedKlass();
}
// return Symbol (if unresolved) or Klass (if resolved)
public Object getKlass() {
if (Assert.ASSERTS_ENABLED) {
Assert.that(isKlassConstant(), "not a klass literal");
}
// tag change from 'unresolved' to 'klass' does not happen atomically.
// We just look at the object at the corresponding index and
// decide based on the oop type.
ConstantPool cpool = method().getConstants();
int cpIndex = poolIndex();
return cpool.getKlassNameAt(cpIndex);
}
public static BytecodeLoadConstant at(Method method, int bci) {
BytecodeLoadConstant b = new BytecodeLoadConstant(method, bci);
if (Assert.ASSERTS_ENABLED) {
b.verify();
}
return b;
}
/** Like at, but returns null if the BCI is not at ldc or ldc_w or ldc2_w */
public static BytecodeLoadConstant atCheck(Method method, int bci) {
BytecodeLoadConstant b = new BytecodeLoadConstant(method, bci);
return (b.isValid() ? b : null);
}
public static BytecodeLoadConstant at(BytecodeStream bcs) {
return new BytecodeLoadConstant(bcs.method(), bcs.bci());
}
public String getConstantValue() {
ConstantPool cpool = method().getConstants();
int cpIndex = poolIndex();
ConstantTag ctag = cpool.getTagAt(cpIndex);
if (ctag.isInt()) {
return "<int " + Integer.toString(cpool.getIntAt(cpIndex)) +">";
} else if (ctag.isLong()) {
return "<long " + Long.toString(cpool.getLongAt(cpIndex)) + "L>";
} else if (ctag.isFloat()) {
return "<float " + Float.toString(cpool.getFloatAt(cpIndex)) + "F>";
} else if (ctag.isDouble()) {
return "<double " + Double.toString(cpool.getDoubleAt(cpIndex)) + "D>";
} else if (ctag.isString()) {
// tag change from 'unresolved' to 'string' does not happen atomically.
// We just look at the object at the corresponding index and
// decide based on the oop type.
Symbol sym = cpool.getUnresolvedStringAt(cpIndex);
return "<String \"" + sym.asString() + "\">";
} else if (ctag.isKlass() || ctag.isUnresolvedKlass()) {
// tag change from 'unresolved' to 'klass' does not happen atomically.
// We just look at the object at the corresponding index and
// decide based on the oop type.
ConstantTag tag = cpool.getTagAt(cpIndex);
if (tag.isKlass()) {
Klass k = cpool.getKlassAt(cpIndex);
return "<Class " + k.getName().asString() + "@" + k.getAddress() + ">";
} else if (tag.isUnresolvedKlass()) {
Symbol sym = cpool.getKlassNameAt(cpIndex);
return "<Class " + sym.asString() + ">";
} else {
throw new RuntimeException("should not reach here");
}
} else if (ctag.isMethodHandle()) {
Oop x = getCachedConstant();
int refidx = cpool.getMethodHandleIndexAt(cpIndex);
int refkind = cpool.getMethodHandleRefKindAt(cpIndex);
return "<MethodHandle kind=" + Integer.toString(refkind) +
" ref=" + Integer.toString(refidx)
+ (x == null ? "" : " @" + x.getHandle()) + ">";
} else if (ctag.isMethodType()) {
Oop x = getCachedConstant();
int refidx = cpool.getMethodTypeIndexAt(cpIndex);
return "<MethodType " + cpool.getSymbolAt(refidx).asString()
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