/* returns the field structure corresponding to the profile entry
* variable in the form: <signature> % <name>
*/
Field* getFieldFromProfileVar(const char* var, const ClassObject* clazz)
{
char* pos;
char* sig;
char* name;
InstField* ifield;
StaticField* sfield;
Field* field = NULL;
// TODO: Can we avoid the allocation if we replace the '%'?
// Need to make sure there isn't a locking problem if that route
// is taken.
pos = index(var, '%');
sig = strndup(var, pos-var);
name = strdup(pos+1);
/* Try both static and instance fields */
ifield = dvmFindInstanceFieldHier(clazz, name, sig);
if (ifield != NULL) {
field = (Field*) ifield;
} else {
sfield = dvmFindStaticFieldHier(clazz, name, sig);
if (sfield != NULL) {
field = (Field*) sfield;
}
}
free(sig);
free(name);
return field;
}
// Based on dvmResolveInstField/dvmResolveStaticField.
static void preloadDexCachesResolveField(DvmDex* pDvmDex, uint32_t fieldIdx, bool instance) {
Field* field = dvmDexGetResolvedField(pDvmDex, fieldIdx);
if (field != NULL) {
return;
}
const DexFile* pDexFile = pDvmDex->pDexFile;
const DexFieldId* pFieldId = dexGetFieldId(pDexFile, fieldIdx);
ClassObject* clazz = dvmDexGetResolvedClass(pDvmDex, pFieldId->classIdx);
if (clazz == NULL) {
return;
}
// Skip static fields for uninitialized classes because a filled
// cache entry implies the class is initialized.
if (!instance && !dvmIsClassInitialized(clazz)) {
return;
}
const char* fieldName = dexStringById(pDexFile, pFieldId->nameIdx);
const char* signature = dexStringByTypeIdx(pDexFile, pFieldId->typeIdx);
if (instance) {
field = dvmFindInstanceFieldHier(clazz, fieldName, signature);
} else {
field = dvmFindStaticFieldHier(clazz, fieldName, signature);
}
if (field == NULL) {
return;
}
// ALOGI("VMRuntime.preloadDexCaches found field %s %s.%s",
// signature, clazz->descriptor, fieldName);
dvmDexSetResolvedField(pDvmDex, fieldIdx, field);
}
/*
* Resolve a static field reference. The DexFile format doesn't distinguish
* between static and instance field references, so the "resolved" pointer
* in the Dex struct will have the wrong type. We trivially cast it here.
*
* Causes the field's class to be initialized.
*/
StaticField* dvmResolveStaticField(const ClassObject* referrer, u4 sfieldIdx)
{
DvmDex* pDvmDex = referrer->pDvmDex;
ClassObject* resClass;
const DexFieldId* pFieldId;
StaticField* resField;
pFieldId = dexGetFieldId(pDvmDex->pDexFile, sfieldIdx);
/*
* Find the field's class.
*/
resClass = dvmResolveClass(referrer, pFieldId->classIdx, false);
if (resClass == NULL) {
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
resField = dvmFindStaticFieldHier(resClass,
dexStringById(pDvmDex->pDexFile, pFieldId->nameIdx),
dexStringByTypeIdx(pDvmDex->pDexFile, pFieldId->typeIdx));
if (resField == NULL) {
dvmThrowNoSuchFieldError(
dexStringById(pDvmDex->pDexFile, pFieldId->nameIdx));
return NULL;
}
/*
* If we're the first to resolve the field in which this class resides,
* we need to do it now. Note that, if the field was inherited from
* a superclass, it is not necessarily the same as "resClass".
*/
if (!dvmIsClassInitialized(resField->clazz) &&
!dvmInitClass(resField->clazz))
{
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
/*
* If the class has been initialized, add a pointer to our data structure
* so we don't have to jump through the hoops again. If it's still
* initializing (i.e. this thread is executing <clinit>), don't do
* the store, otherwise other threads could use the field without waiting
* for class init to finish.
*/
if (dvmIsClassInitialized(resField->clazz)) {
dvmDexSetResolvedField(pDvmDex, sfieldIdx, (Field*) resField);
} else {
LOGVV("--- not caching resolved field %s.%s (class init=%d/%d)",
resField->clazz->descriptor, resField->name,
dvmIsClassInitializing(resField->clazz),
dvmIsClassInitialized(resField->clazz));
}
return resField;
}
/*
* Resolve a static field reference. The DexFile format doesn't distinguish
* between static and instance field references, so the "resolved" pointer
* in the Dex struct will have the wrong type. We trivially cast it here.
*
* Causes the field's class to be initialized.
*/
StaticField* dvmResolveStaticField(const ClassObject* referrer, u4 sfieldIdx)
{
DvmDex* pDvmDex = referrer->pDvmDex;
ClassObject* resClass;
const DexFieldId* pFieldId;
StaticField* resField;
pFieldId = dexGetFieldId(pDvmDex->pDexFile, sfieldIdx);
/*
* Find the field's class.
*/
resClass = dvmResolveClass(referrer, pFieldId->classIdx, false);
if (resClass == NULL) {
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
resField = dvmFindStaticFieldHier(resClass,
dexStringById(pDvmDex->pDexFile, pFieldId->nameIdx),
dexStringByTypeIdx(pDvmDex->pDexFile, pFieldId->typeIdx));
if (resField == NULL) {
dvmThrowException("Ljava/lang/NoSuchFieldError;",
dexStringById(pDvmDex->pDexFile, pFieldId->nameIdx));
return NULL;
}
/*
* If we're the first to resolve the field in which this class resides,
* we need to do it now. Note that, if the field was inherited from
* a superclass, it is not necessarily the same as "resClass".
*/
if (!dvmIsClassInitialized(resField->field.clazz) &&
!dvmInitClass(resField->field.clazz))
{
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
/*
* The class is initialized, the method has been found. Add a pointer
* to our data structure so we don't have to jump through the hoops again.
*/
dvmDexSetResolvedField(pDvmDex, sfieldIdx, (Field*) resField);
return resField;
}
/*
* 在当前的类或者父类中查找相匹配的静态字段，如果没有找到才返回值为NULL
*
*/
StaticField* dvmFindStaticFieldHier(const ClassObject* clazz,
const char* fieldName, const char* signature)
{
StaticField* pField;
/*
* Search for a match in the current class.
*/
pField = dvmFindStaticField(clazz, fieldName, signature);
if (pField != NULL)
return pField;
/*
* See if it's in any of our interfaces. We don't check interfaces
* inherited from the superclass yet.
*
* (Note the set may have been stripped down because of redundancy with
* the superclass; see notes in createIftable.)
*/
int i = 0;
if (clazz->super != NULL) {
assert(clazz->iftableCount >= clazz->super->iftableCount);
i = clazz->super->iftableCount;
}
for ( ; i < clazz->iftableCount; i++) {
ClassObject* iface = clazz->iftable[i].clazz;
pField = dvmFindStaticField(iface, fieldName, signature);
if (pField != NULL)
return pField;
}
if (clazz->super != NULL)
return dvmFindStaticFieldHier(clazz->super, fieldName, signature);
else
return NULL;
}
