C++ VMExecutionContext类代码示例

AutoloadHandler::Result AutoloadHandler::loadFromMap(const String& name,
                                                     const String& kind,
                                                     bool toLower,
                                                     const T &checkExists) {
  assert(!m_map.isNull());
  while (true) {
    CVarRef &type_map = m_map.get()->get(kind);
    auto const typeMapCell = type_map.asCell();
    if (typeMapCell->m_type != KindOfArray) return Failure;
    String canonicalName = toLower ? f_strtolower(name) : name;
    CVarRef &file = typeMapCell->m_data.parr->get(canonicalName);
    bool ok = false;
    if (file.isString()) {
      String fName = file.toCStrRef().get();
      if (fName.get()->data()[0] != '/') {
        if (!m_map_root.empty()) {
          fName = m_map_root + fName;
        }
      }
      try {
        Transl::VMRegAnchor _;
        bool initial;
        VMExecutionContext* ec = g_vmContext;
        Unit* u = ec->evalInclude(fName.get(), nullptr, &initial);
        if (u) {
          if (initial) {
            TypedValue retval;
            ec->invokeFunc(&retval, u->getMain(), null_array,
                           nullptr, nullptr, nullptr, nullptr,
                           ExecutionContext::InvokePseudoMain);
            tvRefcountedDecRef(&retval);
          }
          ok = true;
        }
      } catch (...) {}
    }
    if (ok && checkExists(name)) {
      return Success;
    }
    CVarRef &func = m_map.get()->get(s_failure);
    if (func.isNull()) return Failure;
    // can throw, otherwise
    //  - true means the map was updated. try again
    //  - false means we should stop applying autoloaders (only affects classes)
    //  - anything else means keep going
    Variant action = vm_call_user_func(func, make_packed_array(kind, name));
    auto const actionCell = action.asCell();
    if (actionCell->m_type == KindOfBoolean) {
      if (actionCell->m_data.num) continue;
      return StopAutoloading;
    }
    return ContinueAutoloading;
  }
}

const Func*
StaticMethodCache::lookup(RDS::Handle handle, const NamedEntity *ne,
                          const StringData* clsName,
                          const StringData* methName) {
  StaticMethodCache* thiz = static_cast<StaticMethodCache*>
    (handleToPtr(handle));
  Stats::inc(Stats::TgtCache_StaticMethodMiss);
  Stats::inc(Stats::TgtCache_StaticMethodHit, -1);
  TRACE(1, "miss %s :: %s caller %p\n",
        clsName->data(), methName->data(), __builtin_return_address(0));
  Transl::VMRegAnchor _; // needed for lookupClsMethod.

  ActRec* ar = reinterpret_cast<ActRec*>(vmsp() - kNumActRecCells);
  const Func* f;
  VMExecutionContext* ec = g_vmContext;
  const Class* cls = Unit::loadClass(ne, clsName);
  if (UNLIKELY(!cls)) {
    raise_error(Strings::UNKNOWN_CLASS, clsName->data());
  }
  LookupResult res = ec->lookupClsMethod(f, cls, methName,
                                         nullptr, // there may be an active this,
                                               // but we can just fall through
                                               // in that case.
                                         arGetContextClass(ec->getFP()),
                                         false /*raise*/);
  if (LIKELY(res == LookupResult::MethodFoundNoThis &&
             !f->isAbstract() &&
             f->isStatic())) {
    f->validate();
    TRACE(1, "fill %s :: %s -> %p\n", clsName->data(),
          methName->data(), f);
    // Do the | here instead of on every call.
    thiz->m_cls = (Class*)(uintptr_t(cls) | 1);
    thiz->m_func = f;
    ar->setClass(const_cast<Class*>(cls));
    return f;
  }
  assert(res != LookupResult::MethodFoundWithThis); // Not possible: no this.
  // We've already sync'ed regs; this is some hard case, we might as well
  // just let the interpreter handle this entirely.
  assert(toOp(*vmpc()) == OpFPushClsMethodD);
  Stats::inc(Stats::Instr_InterpOneFPushClsMethodD);
  Stats::inc(Stats::Instr_TC, -1);
  ec->opFPushClsMethodD();
  // Return whatever func the instruction produced; if nothing was
  // possible we'll either have fataled or thrown.
  assert(ar->m_func);
  ar->m_func->validate();
  // Don't update the cache; this case was too scary to memoize.
  TRACE(1, "unfillable miss %s :: %s -> %p\n", clsName->data(),
        methName->data(), ar->m_func);
  // Indicate to the caller that there is no work to do.
  return nullptr;
}

int DebuggerProxy::getRealStackDepth() {
  TRACE(2, "DebuggerProxy::getRealStackDepth\n");
  int depth = 0;
  VMExecutionContext* context = g_vmContext;
  ActRec *fp = context->getFP();
  if (!fp) return 0;

  while (fp != nullptr) {
    fp = context->getPrevVMState(fp, nullptr, nullptr);
    depth++;
  }
  return depth;
}

void TranslatorX64::fCallArrayHelper(const Offset pcOff, const Offset pcNext) {
  DECLARE_FRAME_POINTER(framePtr);
  ActRec* fp = (ActRec*)framePtr->m_savedRbp;

  VMExecutionContext *ec = g_vmContext;
  ec->m_fp = fp;
  ec->m_stack.top() = sp;
  ec->m_pc = curUnit()->at(pcOff);
  PC pc = curUnit()->at(pcNext);

  tl_regState = REGSTATE_CLEAN;
  bool runFunc = ec->doFCallArray(pc);
  sp = ec->m_stack.top();
  tl_regState = REGSTATE_DIRTY;
  if (!runFunc) return;

  ec->m_fp->m_savedRip = framePtr->m_savedRip;
  // smash our return and frame pointer chain
  framePtr->m_savedRip = (uint64_t)ec->m_fp->m_func->getFuncBody();
  framePtr->m_savedRbp = (uint64_t)ec->m_fp;
}

const uchar* InstPointInfo::lookupPC() {
  TRACE(2, "InstPointInfo::lookupPC\n");
  VMExecutionContext* context = g_vmContext;
  if (m_locType == LocHere) {
    // Instrument to current location
    ActRec *fp = context->getFP();
    if (!fp) {
      return nullptr;
    }
    PC pc = context->getPC();
    HPHP::Unit *unit = fp->m_func->unit();
    if (!unit) {
      return nullptr;
    }
    m_file = unit->filepath()->data();
    m_line = unit->getLineNumber(unit->offsetOf(pc));
    return pc;
  }
  // TODO for file and line
  return nullptr;
}

const Func*
StaticMethodFCache::lookupIR(RDS::Handle handle, const Class* cls,
                             const StringData* methName, TypedValue* vmfp) {
  assert(cls);
  StaticMethodFCache* thiz = static_cast<StaticMethodFCache*>
    (handleToPtr(handle));
  Stats::inc(Stats::TgtCache_StaticMethodFMiss);
  Stats::inc(Stats::TgtCache_StaticMethodFHit, -1);

  const Func* f;
  VMExecutionContext* ec = g_vmContext;
  LookupResult res = ec->lookupClsMethod(f, cls, methName,
                                         nullptr,
                                         arGetContextClass((ActRec*)vmfp),
                                         false /*raise*/);
  assert(res != LookupResult::MethodFoundWithThis); // Not possible: no this.
  if (LIKELY(res == LookupResult::MethodFoundNoThis && !f->isAbstract())) {
    // We called lookupClsMethod with a NULL this and got back a
    // method that may or may not be static. This implies that
    // lookupClsMethod, given the same class and the same method name,
    // will never return MagicCall*Found or MethodNotFound. It will
    // always return the same f and if we do give it a this it will
    // return MethodFoundWithThis iff (this->instanceof(cls) &&
    // !f->isStatic()). this->instanceof(cls) is always true for
    // FPushClsMethodF because it is only used for self:: and parent::
    // calls. So, if we store f and its staticness we can handle calls
    // with and without this completely in assembly.
    f->validate();
    thiz->m_func = f;
    thiz->m_static = f->isStatic();
    TRACE(1, "fill staticfcache %s :: %s -> %p\n",
          cls->name()->data(), methName->data(), f);
    Stats::inc(Stats::TgtCache_StaticMethodFFill);
    return f;
  }

  return nullptr;
}

Class* Unit::defClass(PreClass* preClass,
                      bool failIsFatal /* = true */) {
  Class* const* clsList = preClass->namedEntity()->clsList();
  Class* top = *clsList;
  if (top) {
    Class *cls = top->getCached();
    if (cls) {
      // Raise a fatal unless the existing class definition is identical to the
      // one this invocation would create.
      if (cls->preClass() != preClass) {
        if (failIsFatal) {
          raise_error("Class already declared: %s", preClass->name()->data());
        }
        return NULL;
      }
      return cls;
    }
  }
  // Get a compatible Class, and add it to the list of defined classes.

  Class* parent = NULL;
  for (;;) {
    // Search for a compatible extant class.  Searching from most to least
    // recently created may have better locality than alternative search orders.
    // In addition, its the only simple way to make this work lock free...
    for (Class* class_ = top; class_ != NULL; class_ = class_->m_nextClass) {
      if (class_->preClass() != preClass) continue;

      Class::Avail avail = class_->avail(parent, failIsFatal /*tryAutoload*/);
      if (LIKELY(avail == Class::AvailTrue)) {
        class_->setCached();
        DEBUGGER_ATTACHED_ONLY(phpDefClassHook(class_));
        return class_;
      }
      if (avail == Class::AvailFail) {
        if (failIsFatal) {
          raise_error("unknown class %s", parent->name()->data());
        }
        return NULL;
      }
      ASSERT(avail == Class::AvailFalse);
    }

    // Create a new class.
    if (!parent && preClass->parent()->size() != 0) {
      parent = Unit::getClass(preClass->parent(), failIsFatal);
      if (parent == NULL) {
        if (failIsFatal) {
          raise_error("unknown class %s", preClass->parent()->data());
        }
        return NULL;
      }
    }

    VMExecutionContext* ec = g_vmContext;
    ActRec* fp = ec->getFP();
    PC pc = ec->getPC();

    bool needsFrame = ec->m_stack.top() &&
      (!fp || fp->m_func->unit() != preClass->unit());

    if (needsFrame) {
      /*
        we can be called from Unit::merge, which hasnt yet setup
        the frame (because often it doesnt need to).
        Set up a fake frame here, in case of errors.
        But note that mergeUnit is called for systemlib etc before the
        stack has been setup. So dont do anything if m_stack.top()
        is NULL
      */
      ActRec &tmp = *ec->m_stack.allocA();
      tmp.m_savedRbp = (uint64_t)fp;
      tmp.m_savedRip = 0;
      tmp.m_func = preClass->unit()->getMain();
      tmp.m_soff = preClass->getOffset() - tmp.m_func->base();
      tmp.setThis(NULL);
      tmp.m_varEnv = 0;
      tmp.initNumArgs(0);
      ec->m_fp = &tmp;
      ec->m_pc = preClass->unit()->at(preClass->getOffset());
      ec->pushLocalsAndIterators(tmp.m_func);
    }
    ClassPtr newClass(Class::newClass(preClass, parent));
    if (needsFrame) {
      ec->m_stack.top() = (Cell*)(ec->m_fp+1);
      ec->m_fp = fp;
      ec->m_pc = pc;
    }
    Lock l(Unit::s_classesMutex);
    /*
      We could re-enter via Unit::getClass() or class_->avail(), so
      no need for *clsList to be volatile
    */
    if (UNLIKELY(top != *clsList)) {
      top = *clsList;
      continue;
    }
    if (top) {
      newClass->m_cachedOffset = top->m_cachedOffset;
    } else {
//.........这里部分代码省略.........