C++ AnyFunctionRef::getGenericEnvironment方法代码示例

static void emitCaptureArguments(SILGenFunction &SGF,
                                 AnyFunctionRef closure,
                                 CapturedValue capture,
                                 uint16_t ArgNo) {

  auto *VD = capture.getDecl();
  SILLocation Loc(VD);
  Loc.markAsPrologue();

  // Local function to get the captured variable type within the capturing
  // context.
  auto getVarTypeInCaptureContext = [&]() -> Type {
    auto interfaceType = VD->getInterfaceType();
    return GenericEnvironment::mapTypeIntoContext(
      closure.getGenericEnvironment(), interfaceType);
  };

  // FIXME: Expansion
  auto expansion = ResilienceExpansion::Minimal;
  switch (SGF.SGM.Types.getDeclCaptureKind(capture, expansion)) {
  case CaptureKind::None:
    break;

  case CaptureKind::Constant: {
    auto type = getVarTypeInCaptureContext();
    auto &lowering = SGF.getTypeLowering(type);
    // Constant decls are captured by value.
    SILType ty = lowering.getLoweredType();
    SILValue val = SGF.F.begin()->createFunctionArgument(ty, VD);

    bool NeedToDestroyValueAtExit = false;

    // If the original variable was settable, then Sema will have treated the
    // VarDecl as an lvalue, even in the closure's use.  As such, we need to
    // allow formation of the address for this captured value.  Create a
    // temporary within the closure to provide this address.
    if (VD->isSettable(VD->getDeclContext())) {
      auto addr = SGF.emitTemporaryAllocation(VD, ty);
      // We have created a copy that needs to be destroyed.
      val = SGF.B.emitCopyValueOperation(Loc, val);
      NeedToDestroyValueAtExit = true;
      lowering.emitStore(SGF.B, VD, val, addr, StoreOwnershipQualifier::Init);
      val = addr;
    }

    SGF.VarLocs[VD] = SILGenFunction::VarLoc::get(val);
    if (auto *AllocStack = dyn_cast<AllocStackInst>(val))
      AllocStack->setArgNo(ArgNo);
    else {
      SILDebugVariable DbgVar(/*Constant*/ true, ArgNo);
      SGF.B.createDebugValue(Loc, val, DbgVar);
    }

    // TODO: Closure contexts should always be guaranteed.
    if (NeedToDestroyValueAtExit && !lowering.isTrivial())
      SGF.enterDestroyCleanup(val);
    break;
  }

  case CaptureKind::Box: {
    // LValues are captured as a retained @box that owns
    // the captured value.
    auto type = getVarTypeInCaptureContext();
    auto boxTy = SGF.SGM.Types.getContextBoxTypeForCapture(VD,
                               SGF.SGM.Types.getLoweredRValueType(type),
                               SGF.F.getGenericEnvironment(), /*mutable*/ true);
    SILValue box = SGF.F.begin()->createFunctionArgument(
        SILType::getPrimitiveObjectType(boxTy), VD);
    SILValue addr = SGF.B.createProjectBox(VD, box, 0);
    SGF.VarLocs[VD] = SILGenFunction::VarLoc::get(addr, box);
    SILDebugVariable DbgVar(/*Constant*/ false, ArgNo);
    SGF.B.createDebugValueAddr(Loc, addr, DbgVar);
    break;
  }
  case CaptureKind::StorageAddress: {
    // Non-escaping stored decls are captured as the address of the value.
    auto type = getVarTypeInCaptureContext();
    SILType ty = SGF.getLoweredType(type).getAddressType();
    SILValue addr = SGF.F.begin()->createFunctionArgument(ty, VD);
    SGF.VarLocs[VD] = SILGenFunction::VarLoc::get(addr);
    SILDebugVariable DbgVar(/*Constant*/ true, ArgNo);
    SGF.B.createDebugValueAddr(Loc, addr, DbgVar);
    break;
  }
  }
}

static void emitCaptureArguments(SILGenFunction &gen,
                                 AnyFunctionRef closure,
                                 CapturedValue capture,
                                 unsigned ArgNo) {

  auto *VD = capture.getDecl();
  SILLocation Loc(VD);
  Loc.markAsPrologue();

  // Local function to get the captured variable type within the capturing
  // context.
  auto getVarTypeInCaptureContext = [&]() -> Type {
    auto interfaceType = VD->getInterfaceType();
    return GenericEnvironment::mapTypeIntoContext(
      closure.getGenericEnvironment(), interfaceType);
  };

  switch (gen.SGM.Types.getDeclCaptureKind(capture)) {
  case CaptureKind::None:
    break;

  case CaptureKind::Constant: {
    auto type = getVarTypeInCaptureContext();
    auto &lowering = gen.getTypeLowering(type);
    // Constant decls are captured by value.
    SILType ty = lowering.getLoweredType();
    SILValue val = gen.F.begin()->createFunctionArgument(ty, VD);

    // If the original variable was settable, then Sema will have treated the
    // VarDecl as an lvalue, even in the closure's use.  As such, we need to
    // allow formation of the address for this captured value.  Create a
    // temporary within the closure to provide this address.
    if (VD->isSettable(VD->getDeclContext())) {
      auto addr = gen.emitTemporaryAllocation(VD, ty);
      lowering.emitStore(gen.B, VD, val, addr, StoreOwnershipQualifier::Init);
      val = addr;
    }

    gen.VarLocs[VD] = SILGenFunction::VarLoc::get(val);
    if (auto *AllocStack = dyn_cast<AllocStackInst>(val))
      AllocStack->setArgNo(ArgNo);
    else 
      gen.B.createDebugValue(Loc, val, {/*Constant*/true, ArgNo});

    // TODO: Closure contexts should always be guaranteed.
    if (!gen.SGM.M.getOptions().EnableGuaranteedClosureContexts
        && !lowering.isTrivial())
      gen.enterDestroyCleanup(val);
    break;
  }

  case CaptureKind::Box: {
    // LValues are captured as a retained @box that owns
    // the captured value.
    auto type = getVarTypeInCaptureContext();
    auto boxTy = gen.SGM.Types.getContextBoxTypeForCapture(VD,
                               gen.getLoweredType(type).getSwiftRValueType(),
                               gen.F.getGenericEnvironment(), /*mutable*/ true);
    SILValue box = gen.F.begin()->createFunctionArgument(
        SILType::getPrimitiveObjectType(boxTy), VD);
    SILValue addr = gen.B.createProjectBox(VD, box, 0);
    gen.VarLocs[VD] = SILGenFunction::VarLoc::get(addr, box);
    gen.B.createDebugValueAddr(Loc, addr, {/*Constant*/false, ArgNo});
    if (!gen.SGM.M.getOptions().EnableGuaranteedClosureContexts)
      gen.Cleanups.pushCleanup<StrongReleaseCleanup>(box);
    break;
  }
  case CaptureKind::StorageAddress: {
    // Non-escaping stored decls are captured as the address of the value.
    auto type = getVarTypeInCaptureContext();
    SILType ty = gen.getLoweredType(type).getAddressType();
    SILValue addr = gen.F.begin()->createFunctionArgument(ty, VD);
    gen.VarLocs[VD] = SILGenFunction::VarLoc::get(addr);
    gen.B.createDebugValueAddr(Loc, addr, {/*Constant*/true, ArgNo});
    break;
  }
  }
}