[OpaqueValues] Don't emit temporary in one case.

When creating a foreign-to-native thunk, create a temporary when the
foreign convention is indirect-non-inout only when using lowered
addresses.

Author: nate-chandler

lib/SILGen/SILGenBridging.cpp

@@ -2242,13 +2242,15 @@ void SILGenFunction::emitForeignToNativeThunk(SILDeclRef thunk) {
         auto bridged = emitNativeToBridgedValue(fd, param, nativeFormalType,
                                                 foreignFormalType,
                                                 foreignLoweredTy);
-        if (foreignParam.getConvention() == ParameterConvention::Indirect_In ||
-            foreignParam.getConvention() == ParameterConvention::Indirect_In_Guaranteed) {
+        if (useLoweredAddresses() &&
+            (foreignParam.getConvention() == ParameterConvention::Indirect_In ||
+             foreignParam.getConvention() ==
+                 ParameterConvention::Indirect_In_Guaranteed)) {
           auto temp = emitTemporaryAllocation(fd, bridged.getType());
           bridged.forwardInto(*this, fd, temp);
           bridged = emitManagedBufferWithCleanup(temp);
         }
-        
+
         if (memberStatus.isInstance() && isSelf) {
           // Fill in the `self` space.
           args[memberStatus.getSelfIndex()] = bridged;

test/SILGen/opaque_values_cxx.swift

@@ -1,5 +1,10 @@
 // RUN: %target-swift-emit-silgen -enable-sil-opaque-values -Xllvm -sil-full-demangle -cxx-interoperability-mode=swift-5.9 -import-objc-header %S/Inputs/opaque_values_cxx.h -primary-file %s | %FileCheck %s --check-prefix=CHECK
 
+// TODO: Find the relevant mangled name instead of
+// $sSo3stdO3__1O0020___wrap_iter__udAAdDaVSQSCSQ2eeoiySbx_xtFZTW for other
+// platforms.
+// REQUIRES: VENDOR=apple
+
 import Cxx
 
 // CHECK-LABEL: sil {{.*}}[ossa] @$sSo3stdO{{(3__1O)?}}0042vectorUInt32allocatorUInt32_mzFHjGjjqraEeaV3Cxx0B8SequenceSCA{{.*}}P13__beginUnsafe11RawIteratorQzyFTW : {{.*}} {
@@ -10,6 +15,12 @@ import Cxx
 // CHECK:         end_borrow [[VECTOR]]
 // CHECK:         return [[BEGIN]]
 // CHECK-LABEL: } // end sil function '$sSo3stdO{{(3__1O)?}}0042vectorUInt32allocatorUInt32_mzFHjGjjqraEeaV3Cxx0B8SequenceSCA{{.*}}P13__beginUnsafe11RawIteratorQzyFTW'
+// CHECK-LABEL: sil {{.*}}[ossa] @$sSo3stdO{{(3__1O)?}}0020___wrap_iter__udAAdDaVSQSCSQ2eeoiySbx_xtFZTW : {{.*}} {
+// CHECK:       bb0([[LHS:%[^,]+]] : $std.__1.__wrap_iter<_>, [[RHS:%[^,]+]] :
+// CHECK:         [[CALLEE:%[^,]+]] = function_ref @$sSo2eeoiySbSo3stdO{{(3__1O)?}}0020___wrap_iter__udAAdDaV_AGtFTO
+// CHECK:         [[EQUAL:%[^,]+]] = apply [[CALLEE]]([[LHS]], [[RHS]])
+// CHECK:         return [[EQUAL]]
+// CHECK-LABEL: } // end sil function '$sSo3stdO{{(3__1O)?}}0020___wrap_iter__udAAdDaVSQSCSQ2eeoiySbx_xtFZTW'
 func test_cxx_vector_uint32t_iterate(_ n: Int, _ vectorOfU32: VectorOfU32) {
   for x in vectorOfU32 {}
 }