/* 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((char *)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 an instance field reference.
*
* Returns NULL and throws an exception on error (no such field, illegal
* access).
*/
InstField* dvmResolveInstField(const ClassObject* referrer, u4 ifieldIdx)
{
DvmDex* pDvmDex = referrer->pDvmDex;
ClassObject* resClass;
const DexFieldId* pFieldId;
InstField* resField;
LOGVV("--- resolving field %u (referrer=%s cl=%p)",
ifieldIdx, referrer->descriptor, referrer->classLoader);
pFieldId = dexGetFieldId(pDvmDex->pDexFile, ifieldIdx);
/*
* Find the field's class.
*/
resClass = dvmResolveClass(referrer, pFieldId->classIdx, false);
if (resClass == NULL) {
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
resField = dvmFindInstanceFieldHier(resClass,
dexStringById(pDvmDex->pDexFile, pFieldId->nameIdx),
dexStringByTypeIdx(pDvmDex->pDexFile, pFieldId->typeIdx));
if (resField == NULL) {
dvmThrowNoSuchFieldError(
dexStringById(pDvmDex->pDexFile, pFieldId->nameIdx));
return NULL;
}
/*
* Class must be initialized by now (unless verifier is buggy). We
* could still be in the process of initializing it if the field
* access is from a static initializer.
*/
assert(dvmIsClassInitialized(resField->clazz) ||
dvmIsClassInitializing(resField->clazz));
/*
* The class is initialized (or initializing), the field has been
* found. Add a pointer to our data structure so we don't have to
* jump through the hoops again.
*
* Anything that uses the resolved table entry must have an instance
* of the class, so any class init activity has already happened (or
* been deliberately bypassed when <clinit> created an instance).
* So it's always okay to update the table.
*/
dvmDexSetResolvedField(pDvmDex, ifieldIdx, (Field*)resField);
LOGVV(" field %u is %s.%s",
ifieldIdx, resField->clazz->descriptor, resField->name);
return resField;
}
/*
* Resolve an instance field reference.
*
* Returns NULL and throws an exception on error (no such field, illegal
* access).
*/
InstField* dvmResolveInstField(const ClassObject* referrer, u4 ifieldIdx)
{
DvmDex* pDvmDex = referrer->pDvmDex;
ClassObject* resClass;
const DexFieldId* pFieldId;
InstField* resField;
LOGVV("--- resolving field %u (referrer=%s cl=%p)\n",
ifieldIdx, referrer->descriptor, referrer->classLoader);
pFieldId = dexGetFieldId(pDvmDex->pDexFile, ifieldIdx);
/*
* Find the field's class.
*/
resClass = dvmResolveClass(referrer, pFieldId->classIdx, false);
if (resClass == NULL) {
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
resField = dvmFindInstanceFieldHier(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;
}
/*
* Class must be initialized by now (unless verifier is buggy). We
* could still be in the process of initializing it if the field
* access is from a static initializer.
*/
assert(dvmIsClassInitialized(resField->field.clazz) ||
dvmIsClassInitializing(resField->field.clazz));
/*
* 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, ifieldIdx, (Field*)resField);
LOGVV(" field %u is %s.%s\n",
ifieldIdx, resField->field.clazz->descriptor, resField->field.name);
return resField;
}
/*
* 在当前的类或者它的父类中查找所匹配的实例字段
*
* 通过接口去查找不是必要的，因为接口字段是固有的 (public/static/final)
*/
InstField* dvmFindInstanceFieldHier(const ClassObject* clazz,
const char* fieldName, const char* signature)
{
InstField* pField;
/*
* Search for a match in the current class.
*/
pField = dvmFindInstanceField(clazz, fieldName, signature);
if (pField != NULL)
return pField;
if (clazz->super != NULL)
return dvmFindInstanceFieldHier(clazz->super, fieldName, signature);
else
return NULL;
}
