Fix LoadBorrowImmutabilityChecker for partial applies

lib/SIL/Verifier/LoadBorrowImmutabilityChecker.cpp

@@ -243,6 +243,17 @@ bool GatherWritesVisitor::visitUse(Operand *op, AccessUseType useTy) {
     return false;
   }
 
+  if (auto *pa = dyn_cast<PartialApplyInst>(user)) {
+    auto argConv = ApplySite(user).getArgumentConvention(*op);
+    if (argConv == SILArgumentConvention::Indirect_In_Guaranteed) {
+      return true;
+    }
+
+    // For all other conventions, the underlying address could be mutated
+    writeAccumulator.push_back(op);
+    return true;
+  }
+
   // Handle a capture-by-address like a write.
   if (auto as = ApplySite::isa(user)) {
     writeAccumulator.push_back(op);

test/SIL/ownership-verifier/load_borrow_invalidation_partial_apply.sil

@@ -0,0 +1,63 @@
+// RUN: %target-sil-opt -enable-sil-verify-all -inline %s -o /dev/null
+
+// Tests here are patterns we should not consider as broken
+
+import Builtin
+
+class SuperKlass {}
+class Klass : SuperKlass {}
+
+struct WrapperStruct {
+  var cls : Klass
+}
+
+sil [ossa] @foo1 : $@convention(thin) (@guaranteed WrapperStruct, @in_guaranteed WrapperStruct) -> () 
+sil [ossa] @foo2 : $@convention(thin) (@owned WrapperStruct, @in_guaranteed WrapperStruct) -> () 
+
+sil [ossa] @test1 : $@convention(thin) (@in_guaranteed WrapperStruct) -> () {
+bb0(%0 :  $*WrapperStruct):
+  %1 = load_borrow %0 : $*WrapperStruct
+  %func = function_ref @foo1 : $@convention(thin) (@guaranteed WrapperStruct, @in_guaranteed WrapperStruct) -> ()
+  %pa = partial_apply [callee_guaranteed] [on_stack] %func(%1, %0) : $@convention(thin) (@guaranteed WrapperStruct, @in_guaranteed WrapperStruct) -> ()
+  end_borrow %1 : $WrapperStruct
+  dealloc_stack %pa : $@noescape @callee_guaranteed () -> () 
+  %res = tuple ()
+  return %res : $()
+}
+
+sil [ossa] @test2 : $@convention(thin) (@in_guaranteed WrapperStruct) -> () {
+bb0(%0 :  $*WrapperStruct):
+  %1 = load_borrow %0 : $*WrapperStruct
+  %copy = copy_value %1 : $WrapperStruct
+  %func = function_ref @foo2 : $@convention(thin) (@owned WrapperStruct, @in_guaranteed WrapperStruct) -> ()
+  %pa = partial_apply %func(%copy, %0) : $@convention(thin) (@owned WrapperStruct, @in_guaranteed WrapperStruct) -> ()
+  end_borrow %1 : $WrapperStruct
+  destroy_value %pa : $@callee_owned () -> () 
+  %res = tuple ()
+  return %res : $()
+}
+
+sil [ossa] @caller1 : $@convention(thin) (@owned WrapperStruct) -> () {
+bb0(%0 :  @owned $WrapperStruct):
+  %stk = alloc_stack $WrapperStruct
+  store %0 to [init] %stk : $*WrapperStruct
+  %func = function_ref @test1 : $@convention(thin) (@in_guaranteed WrapperStruct) -> ()
+  %a = apply %func(%stk) : $@convention(thin) (@in_guaranteed WrapperStruct) -> ()
+  destroy_addr %stk : $*WrapperStruct
+  dealloc_stack %stk : $*WrapperStruct
+  %res = tuple ()
+  return %res : $()
+}
+
+sil [ossa] @caller2 : $@convention(thin) (@owned WrapperStruct) -> () {
+bb0(%0 :  @owned $WrapperStruct):
+  %stk = alloc_stack $WrapperStruct
+  store %0 to [init] %stk : $*WrapperStruct
+  %func = function_ref @test2 : $@convention(thin) (@in_guaranteed WrapperStruct) -> ()
+  %a = apply %func(%stk) : $@convention(thin) (@in_guaranteed WrapperStruct) -> ()
+  destroy_addr %stk : $*WrapperStruct
+  dealloc_stack %stk : $*WrapperStruct
+  %res = tuple ()
+  return %res : $()
+}
+