/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* java.lang.reflect.Field
*/
#include "Dalvik.h"
#include "native/InternalNativePriv.h"
/*
* Get the address of a field from an object. This can be used with "get"
* or "set".
*
* "declaringClass" is the class in which the field was declared. For an
* instance field, "obj" is the object that holds the field data; for a
* static field its value is ignored.
*
* "If the underlying field is static, the class that declared the
* field is initialized if it has not already been initialized."
*
* On failure, throws an exception and returns NULL.
*
* The documentation lists exceptional conditions and the exceptions that
* should be thrown, but doesn't say which exception previals when two or
* more exceptional conditions exist at the same time. For example,
* attempting to set a protected field from an unrelated class causes an
* IllegalAccessException, while passing in a data type that doesn't match
* the field causes an IllegalArgumentException. If code does both at the
* same time, we have to choose one or othe other.
*
* The expected order is:
* (1) Check for illegal access. Throw IllegalAccessException.
* (2) Make sure the object actually has the field. Throw
* IllegalArgumentException.
* (3) Make sure the field matches the expected type, e.g. if we issued
* a "getInteger" call make sure the field is an integer or can be
* converted to an int with a widening conversion. Throw
* IllegalArgumentException.
* (4) Make sure "obj" is not null. Throw NullPointerException.
*
* TODO: we're currently handling #3 after #4, because we don't check the
* widening conversion until we're actually extracting the value from the
* object (which won't work well if it's a null reference).
*/
static JValue* getFieldDataAddr(Object* obj, ClassObject* declaringClass,
int slot, bool isSetOperation, bool noAccessCheck)
{
Field* field;
JValue* result;
field = dvmSlotToField(declaringClass, slot);
assert(field != NULL);
/* verify access */
if (!noAccessCheck) {
if (isSetOperation && dvmIsFinalField(field)) {
dvmThrowException("Ljava/lang/IllegalAccessException;",
"field is marked 'final'");
return NULL;
}
ClassObject* callerClass =
dvmGetCaller2Class(dvmThreadSelf()->curFrame);
/*
* We need to check two things:
* (1) Would an instance of the calling class have access to the field?
* (2) If the field is "protected", is the object an instance of the
* calling class, or is the field's declaring class in the same
* package as the calling class?
*
* #1 is basic access control. #2 ensures that, just because
* you're a subclass of Foo, you can't mess with protected fields
* in arbitrary Foo objects from other packages.
*/
if (!dvmCheckFieldAccess(callerClass, field)) {
dvmThrowException("Ljava/lang/IllegalAccessException;",
"access to field not allowed");
return NULL;
}
if (dvmIsProtectedField(field)) {
bool isInstance, samePackage;
if (obj != NULL)
isInstance = dvmInstanceof(obj->clazz, callerClass);
else
isInstance = false;
samePackage = dvmInSamePackage(declaringClass, callerClass);
if (!isInstance && !samePackage) {
dvmThrowException("Ljava/lang/IllegalAccessException;",
"access to protected field not allowed");
return NULL;
}
}
}
if (dvmIsStaticField(field)) {
/* init class if necessary, then return ptr to storage in "field" */
if (!dvmIsClassInitialized(declaringClass)) {
if (!dvmInitClass(declaringClass)) {
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
}
result = dvmStaticFieldPtr((StaticField*) field);
} else {
/*
* Verify object is of correct type (i.e. it actually has the
* expected field in it), then grab a pointer to obj storage.
* The call to dvmVerifyObjectInClass throws an NPE if "obj" is NULL.
*/
if (!dvmVerifyObjectInClass(obj, declaringClass)) {
assert(dvmCheckException(dvmThreadSelf()));
if (obj != NULL) {
LOGD("Wrong type of object for field lookup: %s %s\n",
obj->clazz->descriptor, declaringClass->descriptor);
}
return NULL;
}
result = dvmFieldPtr(obj, ((InstField*) field)->byteOffset);
}
return result;
}
/*
* public int getFieldModifiers(Class declaringClass, int slot)
*/
static void Dalvik_java_lang_reflect_Field_getFieldModifiers(
const u4* args, JValue* pResult)
{
// ignore thisPtr in args[0]
ClassObject* declaringClass = (ClassObject*) args[1];
int slot = args[2];
Field* field;
field = dvmSlotToField(declaringClass, slot);
RETURN_INT(field->accessFlags & JAVA_FLAGS_MASK);
}
/*
* private Object getField(Object o, Class declaringClass, Class type,
* int slot, boolean noAccessCheck)
*
* Primitive types need to be boxed.
*/
static void Dalvik_java_lang_reflect_Field_getField(const u4* args,
JValue* pResult)
{
// ignore thisPtr in args[0]
Object* obj = (Object*) args[1];
ClassObject* declaringClass = (ClassObject*) args[2];
ClassObject* fieldType = (ClassObject*) args[3];
int slot = args[4];
bool noAccessCheck = (args[5] != 0);
JValue value;
const JValue* fieldPtr;
DataObject* result;
//dvmDumpClass(obj->clazz, kDumpClassFullDetail);
/* get a pointer to the field's data; performs access checks */
fieldPtr = getFieldDataAddr(obj, declaringClass, slot, false,noAccessCheck);
if (fieldPtr == NULL)
RETURN_VOID();
/* copy 4 or 8 bytes out */
if (fieldType->primitiveType == PRIM_LONG ||
fieldType->primitiveType == PRIM_DOUBLE)
{
value.j = fieldPtr->j;
} else {
value.i = fieldPtr->i;
}
result = dvmWrapPrimitive(value, fieldType);
dvmReleaseTrackedAlloc((Object*) result, NULL);
RETURN_PTR(result);
}
/*
* private void setField(Object o, Class declaringClass, Class type,
* int slot, boolean noAccessCheck, Object value)
*
* When assigning into a primitive field we will automatically extract
* the value from box types.
*/
static void Dalvik_java_lang_reflect_Field_setField(const u4* args,
JValue* pResult)
{
// ignore thisPtr in args[0]
Object* obj = (Object*) args[1];
ClassObject* declaringClass = (ClassObject*) args[2];
ClassObject* fieldType = (ClassObject*) args[3];
int slot = args[4];
bool noAccessCheck = (args[5] != 0);
Object* valueObj = (Object*) args[6];
JValue* fieldPtr;
JValue value;
/* unwrap primitive, or verify object type */
if (!dvmUnwrapPrimitive(valueObj, fieldType, &value)) {
dvmThrowException("Ljava/lang/IllegalArgumentException;",
"invalid value for field");
RETURN_VOID();
}
/* get a pointer to the field's data; performs access checks */
fieldPtr = getFieldDataAddr(obj, declaringClass, slot, true, noAccessCheck);
if (fieldPtr == NULL)
RETURN_VOID();
/* store 4 or 8 bytes */
if (fieldType->primitiveType == PRIM_LONG ||
fieldType->primitiveType == PRIM_DOUBLE)
{
fieldPtr->j = value.j;
} else if (fieldType->primitiveType == PRIM_NOT) {
if (slot < 0) {
StaticField *sfield;
sfield = (StaticField *)dvmSlotToField(declaringClass, slot);
assert(fieldPtr == &sfield->value);
dvmSetStaticFieldObject(sfield, value.l);
} else {
int offset = declaringClass->ifields[slot].byteOffset;
assert(fieldPtr == (JValue *)BYTE_OFFSET(obj, offset));
dvmSetFieldObject(obj, offset, value.l);
}
} else {
fieldPtr->i = value.i;
}
RETURN_VOID();
}
/*
* Convert a reflection primitive type ordinal (inherited from the previous
* VM's reflection classes) to our value.
*/
static PrimitiveType convPrimType(int typeNum)
{
static const PrimitiveType conv[PRIM_MAX] = {
PRIM_NOT, PRIM_BOOLEAN, PRIM_BYTE, PRIM_CHAR, PRIM_SHORT,
PRIM_INT, PRIM_FLOAT, PRIM_LONG, PRIM_DOUBLE
};
if (typeNum <= 0 || typeNum > 8)
return PRIM_NOT;
return conv[typeNum];
}
/*
* Primitive field getters, e.g.:
* private double getIField(Object o, Class declaringClass,
* Class type, int slot, boolean noAccessCheck, int type_no)
*
* The "type_no" is defined by the java.lang.reflect.Field class.
*/
static void Dalvik_java_lang_reflect_Field_getPrimitiveField(const u4* args,
JValue* pResult)
{
// ignore thisPtr in args[0]
Object* obj = (Object*) args[1];
ClassObject* declaringClass = (ClassObject*) args[2];
ClassObject* fieldType = (ClassObject*) args[3];
int slot = args[4];
bool noAccessCheck = (args[5] != 0);
int typeNum = args[6];
PrimitiveType targetType = convPrimType(typeNum);
const JValue* fieldPtr;
JValue value;
if (!dvmIsPrimitiveClass(fieldType)) {
dvmThrowException("Ljava/lang/IllegalArgumentException;",
"not a primitive field");
RETURN_VOID();
}
/* get a pointer to the field's data; performs access checks */
fieldPtr = getFieldDataAddr(obj, declaringClass, slot, false,noAccessCheck);
if (fieldPtr == NULL)
RETURN_VOID();
/* copy 4 or 8 bytes out */
if (fieldType->primitiveType == PRIM_LONG ||
fieldType->primitiveType == PRIM_DOUBLE)
{
value.j = fieldPtr->j;
} else {
value.i = fieldPtr->i;
}
/* retrieve value, performing a widening conversion if necessary */
if (dvmConvertPrimitiveValue(fieldType->primitiveType, targetType,
&(value.i), &(pResult->i)) < 0)
{
dvmThrowException("Ljava/lang/IllegalArgumentException;",
"invalid primitive conversion");
RETURN_VOID();
}
}
/*
* Primitive field setters, e.g.:
* private void setIField(Object o, Class declaringClass,
* Class type, int slot, boolean noAccessCheck, int type_no, int value)
*
* The "type_no" is defined by the java.lang.reflect.Field class.
*/
static void Dalvik_java_lang_reflect_Field_setPrimitiveField(const u4* args,
JValue* pResult)
{
// ignore thisPtr in args[0]
Object* obj = (Object*) args[1];
ClassObject* declaringClass = (ClassObject*) args[2];
ClassObject* fieldType = (ClassObject*) args[3];
int slot = args[4];
bool noAccessCheck = (args[5] != 0);
int typeNum = args[6];
const s4* valuePtr = (s4*) &args[7];
PrimitiveType srcType = convPrimType(typeNum);
JValue* fieldPtr;
JValue value;
if (!dvmIsPrimitiveClass(fieldType)) {
dvmThrowException("Ljava/lang/IllegalArgumentException;",
"not a primitive field");
RETURN_VOID();
}
/* convert the 32/64-bit arg to a JValue matching the field type */
if (dvmConvertPrimitiveValue(srcType, fieldType->primitiveType,
valuePtr, &(value.i)) < 0)
{
dvmThrowException("Ljava/lang/IllegalArgumentException;",
"invalid primitive conversion");
RETURN_VOID();
}
/* get a pointer to the field's data; performs access checks */
fieldPtr = getFieldDataAddr(obj, declaringClass, slot, true, noAccessCheck);
if (fieldPtr == NULL)
RETURN_VOID();
/* store 4 or 8 bytes */
if (fieldType->primitiveType == PRIM_LONG ||
fieldType->primitiveType == PRIM_DOUBLE)
{
fieldPtr->j = value.j;
} else {
fieldPtr->i = value.i;
}
RETURN_VOID();
}
/*
* public Annotation[] getDeclaredAnnotations(Class declaringClass, int slot)
*
* Return the annotations declared for this field.
*/
static void Dalvik_java_lang_reflect_Field_getDeclaredAnnotations(
const u4* args, JValue* pResult)
{
// ignore thisPtr in args[0]
ClassObject* declaringClass = (ClassObject*) args[1];
int slot = args[2];
Field* field;
field = dvmSlotToField(declaringClass, slot);
assert(field != NULL);
ArrayObject* annos = dvmGetFieldAnnotations(field);
dvmReleaseTrackedAlloc((Object*) annos, NULL);
RETURN_PTR(annos);
}
/*
* private Object[] getSignatureAnnotation()
*
* Returns the signature annotation.
*/
static void Dalvik_java_lang_reflect_Field_getSignatureAnnotation(const u4* args,
JValue* pResult)
{
// ignore thisPtr in args[0]
ClassObject* declaringClass = (ClassObject*) args[1];
int slot = args[2];
Field* field;
field = dvmSlotToField(declaringClass, slot);
assert(field != NULL);
ArrayObject* arr = dvmGetFieldSignatureAnnotation(field);
dvmReleaseTrackedAlloc((Object*) arr, NULL);
RETURN_PTR(arr);
}
const DalvikNativeMethod dvm_java_lang_reflect_Field[] = {
{ "getFieldModifiers", "(Ljava/lang/Class;I)I",
Dalvik_java_lang_reflect_Field_getFieldModifiers },
{ "getField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZ)Ljava/lang/Object;",
Dalvik_java_lang_reflect_Field_getField },
{ "getBField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)B",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getCField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)C",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getDField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)D",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getFField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)F",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getIField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)I",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getJField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)J",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getSField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)S",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "getZField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZI)Z",
Dalvik_java_lang_reflect_Field_getPrimitiveField },
{ "setField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZLjava/lang/Object;)V",
Dalvik_java_lang_reflect_Field_setField },
{ "setBField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZIB)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setCField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZIC)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setDField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZID)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setFField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZIF)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setIField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZII)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setJField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZIJ)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setSField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZIS)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "setZField", "(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/Class;IZIZ)V",
Dalvik_java_lang_reflect_Field_setPrimitiveField },
{ "getDeclaredAnnotations", "(Ljava/lang/Class;I)[Ljava/lang/annotation/Annotation;",
Dalvik_java_lang_reflect_Field_getDeclaredAnnotations },
{ "getSignatureAnnotation", "(Ljava/lang/Class;I)[Ljava/lang/Object;",
Dalvik_java_lang_reflect_Field_getSignatureAnnotation },
{ NULL, NULL, NULL },
};