SIL: Unwrap reference to value parameter packs in TypeConverter::getAbstractionPattern()

Author: slavapestov

lib/SIL/IR/AbstractionPattern.cpp

@@ -79,7 +79,12 @@ TypeConverter::getAbstractionPattern(VarDecl *var, bool isNonObjC) {
   auto sig = var->getDeclContext()
                  ->getGenericSignatureOfContext()
                  .getCanonicalSignature();
-  auto swiftType = sig.getReducedType(var->getInterfaceType());
+
+  auto interfaceType = var->getInterfaceType();
+  if (auto *packExpansionType = interfaceType->getAs<PackExpansionType>())
+    interfaceType = packExpansionType->getPatternType();
+
+  auto swiftType = sig.getReducedType(interfaceType);
 
   if (isNonObjC)
     return AbstractionPattern(sig, swiftType);

test/SILGen/variadic-generic-tuples.swift

@@ -165,3 +165,40 @@ func wrapTupleElements<each T>(_ value: repeat each T) -> (repeat Wrapper<each T
   // CHECK-NEXT:    [[RET:%.*]] = tuple ()
   // CHECK-NEXT:    return [[RET]] : $()
 }
+
+// CHECK-LABEL: sil hidden [ossa] @$s4main20projectTupleElementsyyAA7WrapperVyxGxQpRvzlF : $@convention(thin) <each T> (@pack_guaranteed Pack{repeat Wrapper<each T>}) -> () {
+func projectTupleElements<each T>(_ value: repeat Wrapper<each T>) {
+  // CHECK: [[VAR:%.*]] = alloc_stack [lexical] $(repeat each T)
+
+  // CHECK-NEXT: [[ZERO:%.*]] = integer_literal $Builtin.Word, 0
+  // CHECK-NEXT: [[ONE:%.*]] = integer_literal $Builtin.Word, 1
+  // CHECK-NEXT: [[PACK_LEN:%.*]] = pack_length $Pack{repeat each T}
+
+  // CHECK-NEXT: br bb1([[ZERO]] : $Builtin.Word)
+
+  // CHECK: bb1([[INDEX:%.*]] : $Builtin.Word):
+  // CHECK-NEXT: [[INDEX_EQ_LEN:%.*]] = builtin "cmp_eq_Word"([[INDEX]] : $Builtin.Word, [[PACK_LEN]] : $Builtin.Word)
+  // CHECK-NEXT: cond_br [[INDEX_EQ_LEN]], bb3, bb2
+
+  // CHECK: bb2:
+  // CHECK-NEXT: [[CUR_INDEX:%.*]] = dynamic_pack_index [[INDEX]] of $Pack{repeat each T}
+  // CHECK-NEXT: open_pack_element [[CUR_INDEX]] of <each T> at <Pack{repeat each T}>, shape $T, uuid "[[UUID:[0-9A-F-]*]]"
+  // CHECK-NEXT: [[TUPLE_ELT_ADDR:%.*]] = tuple_pack_element_addr [[CUR_INDEX]] of [[VAR]] : $*(repeat each T) as $*@pack_element("[[UUID]]") T
+  // CHECK-NEXT: [[VAL_ELT_ADDR:%.*]] = pack_element_get [[CUR_INDEX]] of %0 : $*Pack{repeat Wrapper<each T>} as $*Wrapper<@pack_element("[[UUID]]") T>
+  // CHECK-NEXT: [[TEMP:%.*]] = alloc_stack $Wrapper<@pack_element("[[UUID]]") T>
+  // CHECK-NEXT: copy_addr [[VAL_ELT_ADDR]] to [init] [[TEMP]] : $*Wrapper<@pack_element("[[UUID]]") T>
+  // CHECK-NEXT: [[MEMBER:%.*]] = struct_element_addr [[TEMP]] : $*Wrapper<@pack_element("[[UUID]]") T>, #Wrapper.value
+  // CHECK-NEXT: copy_addr [[MEMBER]] to [init] [[TUPLE_ELT_ADDR]] : $*@pack_element("[[UUID]]") T
+  // CHECK-NEXT: destroy_addr [[TEMP]] : $*Wrapper<@pack_element("[[UUID]]") T>
+  // CHECK-NEXT: dealloc_stack [[TEMP]] : $*Wrapper<@pack_element("[[UUID]]") T>
+  // CHECK-NEXT: [[NEXT_INDEX:%.*]] = builtin "add_Word"([[INDEX]] : $Builtin.Word, [[ONE]] : $Builtin.Word) : $Builtin.Word
+  // CHECK-NEXT: br bb1([[NEXT_INDEX]] : $Builtin.Word)
+
+  // CHECK: bb3:
+  // CHECK-NEXT: destroy_addr [[VAR]] : $*(repeat each T)
+  // CHECK-NEXT: dealloc_stack [[VAR]] : $*(repeat each T)
+  // CHECK-NEXT: [[RET:%.*]] = tuple ()
+  // CHECK-NEXT: return [[RET]] : $()
+
+  let tuple = (repeat (each value).value)
+}