[ABI/Metadata] Add @autoclosure to function parameter flags

Add `@autoclosure` to parameter flags associated with
function type metadata, which makes it possible to correctly
round-trip mangled name <-> metadata of function types which
have parameters marked as `@autoclosure`.

Resolves: rdar://problem/45489901

Author: xedin

include/swift/ABI/MetadataValues.h

@@ -880,7 +880,11 @@ using FunctionTypeFlags = TargetFunctionTypeFlags<size_t>;
 
 template <typename int_type>
 class TargetParameterTypeFlags {
-  enum : int_type { ValueOwnershipMask = 0x7F, VariadicMask = 0x80 };
+  enum : int_type {
+    ValueOwnershipMask = 0x7F,
+    VariadicMask       = 0x80,
+    AutoClosureMask    = 0x100,
+  };
   int_type Data;
 
   constexpr TargetParameterTypeFlags(int_type Data) : Data(Data) {}
@@ -900,8 +904,15 @@ class TargetParameterTypeFlags {
                                               (isVariadic ? VariadicMask : 0));
   }
 
+  constexpr TargetParameterTypeFlags<int_type>
+  withAutoClosure(bool isAutoClosure) const {
+    return TargetParameterTypeFlags<int_type>(
+        (Data & ~AutoClosureMask) | (isAutoClosure ? AutoClosureMask : 0));
+  }
+
   bool isNone() const { return Data == 0; }
   bool isVariadic() const { return Data & VariadicMask; }
+  bool isAutoClosure() const { return Data & AutoClosureMask; }
 
   ValueOwnership getValueOwnership() const {
     return (ValueOwnership)(Data & ValueOwnershipMask);

include/swift/AST/Types.h

@@ -1726,6 +1726,12 @@ class ParameterTypeFlags {
             | ParameterFlags(uint8_t(ownership) << OwnershipShift);
   }
 
+  ParameterTypeFlags withAutoClosure(bool isAutoClosure) const {
+    return ParameterTypeFlags(isAutoClosure
+                                  ? value | ParameterTypeFlags::AutoClosure
+                                  : value - ParameterTypeFlags::AutoClosure);
+  }
+
   bool operator ==(const ParameterTypeFlags &other) const {
     return value.toRaw() == other.value.toRaw();
   }

include/swift/Demangling/TypeDecoder.h

@@ -56,6 +56,7 @@ class FunctionParam {
   void setType(BuiltType type) { Type = type; }
 
   void setVariadic() { Flags = Flags.withVariadic(true); }
+  void setAutoClosure() { Flags = Flags.withAutoClosure(true); }
   void setValueOwnership(ValueOwnership ownership) {
     Flags = Flags.withValueOwnership(ownership);
   }
@@ -252,7 +253,6 @@ class TypeDecoder {
       if (Node->getNumChildren() < 2)
         return BuiltType();
 
-      // FIXME: autoclosure is not represented in function metadata
       FunctionTypeFlags flags;
       if (Node->getKind() == NodeKind::ObjCBlock) {
         flags = flags.withConvention(FunctionMetadataConvention::Block);
@@ -564,6 +564,13 @@ class TypeDecoder {
         setOwnership(ValueOwnership::Owned);
         break;
 
+      case NodeKind::AutoClosureType:
+      case NodeKind::EscapingAutoClosureType: {
+        param.setAutoClosure();
+        hasParamFlags = true;
+        break;
+      }
+
       default:
         break;
       }

lib/IRGen/MetadataRequest.cpp

@@ -928,8 +928,9 @@ namespace {
       // flags.
       auto getABIParameterFlags = [](ParameterTypeFlags flags) {
         return ParameterFlags()
-                 .withValueOwnership(flags.getValueOwnership())
-                 .withVariadic(flags.isVariadic());
+            .withValueOwnership(flags.getValueOwnership())
+            .withVariadic(flags.isVariadic())
+            .withAutoClosure(flags.isAutoClosure());
       };
 
       bool hasFlags = false;

lib/RemoteAST/RemoteAST.cpp

@@ -365,7 +365,8 @@ class RemoteASTTypeBuilder {
       auto ownership = flags.getValueOwnership();
       auto parameterFlags = ParameterTypeFlags()
                                 .withValueOwnership(ownership)
-                                .withVariadic(flags.isVariadic());
+                                .withVariadic(flags.isVariadic())
+                                .withAutoClosure(flags.isAutoClosure());
 
       funcParams.push_back(AnyFunctionType::Param(type, label, parameterFlags));
     }

test/IRGen/dynamic_cast_functions.swift

@@ -55,13 +55,17 @@ let k: (Int, inout Int) -> Void = { _,_ in }
 let l: (inout Int, Float, inout String) -> Void = { _,_,_ in }
 let m: (__shared Int, String, inout Float, Double) -> Void = { _,_,_,_ in }
 let n: () -> Int = { 42 }
+let o: (@autoclosure () -> Int) -> Void = { (x: @autoclosure () -> Int) -> Void in }
+let p: (@autoclosure @escaping () -> Int) -> Void = { (x: @autoclosure @escaping () -> Int) -> Void in }
 
 let i_any: Any = i
 let j_any: Any = j
 let k_any: Any = k
 let l_any: Any = l
 let m_any: Any = m
 let n_any: Any = n
+let o_any: Any = o
+let p_any: Any = p
 
 // CHECK: ok
 print((i_any as? (Int) -> Void) != nil ? "fail" : "ok")
@@ -125,3 +129,20 @@ print((n_any as? () -> Int) != nil ? "ok" : "fail")
 print((n_any as? () -> Void) != nil ? "fail" : "ok")
 // CHECK: ok
 print((n_any as? (Int) -> Int) != nil ? "fail" : "ok")
+
+// CHECK: ok
+print((o_any as? (() -> Int) -> Void) != nil ? "fail" : "ok")
+// CHECK: ok
+print((o_any as? (inout () -> Int) -> Void) != nil ? "fail" : "ok")
+// CHECK: ok
+print((o_any as? (@escaping () -> Int) -> Void) != nil ? "fail" : "ok")
+// CHECK: ok
+print((o_any as? (@autoclosure () -> Int) -> Void) != nil ? "ok" : "fail")
+// CHECK: ok
+print((o_any as? (@autoclosure @escaping () -> Int) -> Void) != nil ? "fail" : "ok")
+// CHECK: ok
+print((p_any as? (@escaping () -> Int) -> Void) != nil ? "fail" : "ok")
+// CHECK: ok
+print((p_any as? (@autoclosure () -> Int) -> Void) != nil ? "fail" : "ok")
+// CHECK: ok
+print((p_any as? (@autoclosure @escaping () -> Int) -> Void) == nil ? "fail" : "ok")

test/IRGen/function_metadata.swift

@@ -53,6 +53,10 @@ func test_arch() {
   arch({(x: inout Int, y: Double, z: String, w: Int8) -> () in })
 
   // CHECK-LABEL: define{{( protected)?}} linkonce_odr hidden swiftcc %swift.metadata_response @"$syyyccMa"
-  // CHECK: call %swift.type* @swift_getFunctionTypeMetadata1({{i(32|64)}} 67108865
+  // CHECK: call %swift.type* @swift_getFunctionTypeMetadata1([[WORD]] 67108865
   arch({(x: @escaping () -> ()) -> () in })
+
+  // CHECK-LABEL: define{{( protected)?}} linkonce_odr hidden swiftcc %swift.metadata_response @"$sySiyXKcMa"
+  // CHECK: call %swift.type* @swift_getFunctionTypeMetadata([[WORD]] 100663297
+  arch({(x: @autoclosure () -> Int) -> Void in })
 }