Ejemplo n.º 1
0
void swift::
collectDefaultImplementationForProtocolMembers(ProtocolDecl *PD,
                    llvm::SmallDenseMap<ValueDecl*, ValueDecl*> &DefaultMap) {
  Type BaseTy = PD->getDeclaredInterfaceType();
  DeclContext *DC = PD->getInnermostDeclContext();
  auto HandleMembers = [&](DeclRange Members) {
    for (Decl *D : Members) {
      auto *VD = dyn_cast<ValueDecl>(D);

      // Skip non-value decl.
      if (!VD)
        continue;

      // Skip decls with empty names, e.g. setter/getters for properties.
      if (VD->getBaseName().empty())
        continue;

      ResolvedMemberResult Result = resolveValueMember(*DC, BaseTy,
                                                       VD->getFullName());
      assert(Result);
      for (auto *Default : Result.getMemberDecls(InterestedMemberKind::All)) {
        if (PD == Default->getDeclContext()->getExtendedProtocolDecl()) {
          DefaultMap.insert({Default, VD});
        }
      }
    }
  };

  // Collect the default implementations for the members in this given protocol.
  HandleMembers(PD->getMembers());

  // Collect the default implementations for the members in the inherited
  // protocols.
  for (auto *IP : PD->getInheritedProtocols())
    HandleMembers(IP->getMembers());
}
Ejemplo n.º 2
0
void AllocOptimize::
computeAvailableValuesFrom(SILBasicBlock::iterator StartingFrom,
                           SILBasicBlock *BB,
                           llvm::SmallBitVector &RequiredElts,
                         SmallVectorImpl<std::pair<SILValue, unsigned>> &Result,
   llvm::SmallDenseMap<SILBasicBlock*, llvm::SmallBitVector, 32> &VisitedBlocks,
                           llvm::SmallBitVector &ConflictingValues) {
  assert(!RequiredElts.none() && "Scanning with a goal of finding nothing?");
  
  // If there is a potential modification in the current block, scan the block
  // to see if the store or escape is before or after the load.  If it is
  // before, check to see if it produces the value we are looking for.
  if (HasLocalDefinition.count(BB)) {
    for (SILBasicBlock::iterator BBI = StartingFrom; BBI != BB->begin();) {
      SILInstruction *TheInst = &*std::prev(BBI);

      // If this instruction is unrelated to the element, ignore it.
      if (!NonLoadUses.count(TheInst)) {
        --BBI;
        continue;
      }
      
      // Given an interesting instruction, incorporate it into the set of
      // results, and filter down the list of demanded subelements that we still
      // need.
      updateAvailableValues(TheInst, RequiredElts, Result, ConflictingValues);
      
      // If this satisfied all of the demanded values, we're done.
      if (RequiredElts.none())
        return;
      
      // Otherwise, keep scanning the block.  If the instruction we were looking
      // at just got exploded, don't skip the next instruction.
      if (&*std::prev(BBI) == TheInst)
        --BBI;
    }
  }
  
  
  // Otherwise, we need to scan up the CFG looking for available values.
  for (auto PI = BB->pred_begin(), E = BB->pred_end(); PI != E; ++PI) {
    SILBasicBlock *PredBB = *PI;
    
    // If the predecessor block has already been visited (potentially due to a
    // cycle in the CFG), don't revisit it.  We can do this safely because we
    // are optimistically assuming that all incoming elements in a cycle will be
    // the same.  If we ever detect a conflicting element, we record it and do
    // not look at the result.
    auto Entry = VisitedBlocks.insert({PredBB, RequiredElts});
    if (!Entry.second) {
      // If we are revisiting a block and asking for different required elements
      // then anything that isn't agreeing is in conflict.
      const auto &PrevRequired = Entry.first->second;
      if (PrevRequired != RequiredElts) {
        ConflictingValues |= (PrevRequired ^ RequiredElts);
        
        RequiredElts &= ~ConflictingValues;
        if (RequiredElts.none())
          return;
      }
      continue;
    }
    
    // Make sure to pass in the same set of required elements for each pred.
    llvm::SmallBitVector Elts = RequiredElts;
    computeAvailableValuesFrom(PredBB->end(), PredBB, Elts, Result,
                               VisitedBlocks, ConflictingValues);
    
    // If we have any conflicting values, don't bother searching for them.
    RequiredElts &= ~ConflictingValues;
    if (RequiredElts.none())
      return;
  }
}