Method compileIndirectCallOp

lib/llvm/compiler.cpp:4283–4374

  }

  void compileIndirectCallOp(const uint32_t TableIndex,
                             const uint32_t FuncTypeIndex) noexcept {
    auto NotNullBB = LLVM::BasicBlock::create(LLContext, F.Fn, "c_i.not_null");
    auto IsNullBB = LLVM::BasicBlock::create(LLContext, F.Fn, "c_i.is_null");
    auto EndBB = LLVM::BasicBlock::create(LLContext, F.Fn, "c_i.end");

    LLVM::Value FuncIndex = stackPop();
    const auto &FuncType = Context.CompositeTypes[FuncTypeIndex]->getFuncType();
    auto FTy = toLLVMType(Context.LLContext, Context.ExecCtxPtrTy, FuncType);
    auto RTy = FTy.getReturnType();

    const size_t ArgSize = FuncType.getParamTypes().size();
    const size_t RetSize =
        RTy.isVoidTy() ? 0 : FuncType.getReturnTypes().size();
    std::vector<LLVM::Value> ArgsVec(ArgSize + 1, nullptr);
    ArgsVec[0] = F.Fn.getFirstParam();
    for (size_t I = 0; I < ArgSize; ++I) {
      const size_t J = ArgSize - I;
      ArgsVec[J] = stackPop();
    }

    std::vector<LLVM::Value> FPtrRetsVec;
    FPtrRetsVec.reserve(RetSize);
    {
      auto FPtr = Builder.createCall(
          Context.getIntrinsic(
              Builder, Executable::Intrinsics::kTableGetFuncSymbol,
              LLVM::Type::getFunctionType(
                  FTy.getPointerTo(),
                  {Context.Int32Ty, Context.Int32Ty, Context.Int32Ty}, false)),
          {LLContext.getInt32(TableIndex), LLContext.getInt32(FuncTypeIndex),
           FuncIndex});
      Builder.createCondBr(
          Builder.createLikely(Builder.createNot(Builder.createIsNull(FPtr))),
          NotNullBB, IsNullBB);
      Builder.positionAtEnd(NotNullBB);

      auto FPtrRet =
          Builder.createCall(LLVM::FunctionCallee{FTy, FPtr}, ArgsVec);
      if (RetSize == 0) {
        // nothing to do
      } else if (RetSize == 1) {
        FPtrRetsVec.push_back(FPtrRet);
      } else {
        for (auto Val : unpackStruct(Builder, FPtrRet)) {
          FPtrRetsVec.push_back(Val);
        }
      }
    }

    Builder.createBr(EndBB);
    Builder.positionAtEnd(IsNullBB);

    std::vector<LLVM::Value> RetsVec;
    {
      LLVM::Value Args = Builder.createArray(ArgSize, kValSize);
      LLVM::Value Rets = Builder.createArray(RetSize, kValSize);
      Builder.createArrayPtrStore(