[sdk][fidl][fpromise][fit] Add Wctad-maybe-unsupported

Bug: 120888
Fixed: 127411
Change-Id: If008aaad4d5a2e9906caac89dc350fb05cadfa19
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/871384
Reviewed-by: Adam Barth <[email protected]>
Commit-Queue: Auto-Submit <[email protected]>
Fuchsia-Auto-Submit: Tamir Duberstein <[email protected]>
API-Review: Adam Barth <[email protected]>
Reviewed-by: Yifei Teng <[email protected]>

Author: tamird

build/cpp/fidl_cpp.gni

@@ -193,9 +193,14 @@ template("_fidl_cpp_library_impl") {
       }
     }
 
-    # TODO(fxbug.dev/120888): Remove `-Wshadow` when the flag is on
-    # by default.
-    cflags_cc = [ "-Wshadow" ]
+    # chromium uses this library, and enables the following flags, so these tests should work with
+    # these flags enabled.
+    #
+    # TODO(fxbug.dev/120888): Remove this when a central definition of SDK warnings exists.
+    cflags_cc = [
+      "-Wctad-maybe-unsupported",
+      "-Wshadow",
+    ]
 
     if (defined(invoker.additional_configs)) {
       configs += invoker.additional_configs

sdk/lib/fidl/cpp/wire/fidl_cpp_wire.api

@@ -26,7 +26,7 @@
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/intrusive_container/wavl_tree.h": "39eb6d96e5d7c7a1b47930cea85a962f",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/intrusive_container/wavl_tree_internal.h": "83b29df78e334e1325d9d94198924239",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/make_response_context.h": "f6cc02ff60043349d7ec40f2ee102185",
-  "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/server_details.h": "d159958fdd9649751ab5e30fa50b4cfd",
+  "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/server_details.h": "e5cad36202de5551b2cb4a728d189986",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/synchronization_checker.h": "4c143e8c9eb85bb4cf0e2c35d3d9cd0a",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/thenable.h": "3f0ac164703381f05766132068212c9e",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/internal/transport.h": "bd1b299b9195bbdf08404e358145d828",
@@ -48,7 +48,7 @@
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/unknown_interactions.h": "99780ed73d3adb008df831471be863f0",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/vector_view.h": "ebf5e1ff94685e75754951171d0e5f62",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/wire_coding_common.h": "88c316337c33da9e26199727b3c44846",
-  "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/wire_coding_traits.h": "b1afa52f6cac7a91f23528510f1aafa7",
+  "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/wire_coding_traits.h": "5840215fa8b4d35f6efe62c08210d9f3",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/wire_decoder.h": "df97148cc05ecad3e208ee754a45a837",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/wire_encoder.h": "1fa6397c5a1dc207d805a7c6d18a616f",
   "pkg/fidl_cpp_wire/include/lib/fidl/cpp/wire/wire_messaging.h": "46008354c21f3d47e311213ac75313e7",

sdk/lib/fidl/cpp/wire/include/lib/fidl/cpp/wire/internal/server_details.h

@@ -387,6 +387,12 @@ struct UnboundThunk {
   std::remove_reference_t<OnUnbound> on_unbound_;
 };
 
+// This suppresses the '-Wctad-maybe-unsupported' compiler warning when CTAD is used.
+//
+// See https://github.com/llvm/llvm-project/blob/42874f6/libcxx/include/__config#L1259-L1261.
+template <class... Tag>
+UnboundThunk(typename Tag::__allow_ctad...) -> UnboundThunk<Tag...>;
+
 }  // namespace internal
 
 }  // namespace fidl

sdk/lib/fidl/cpp/wire/include/lib/fidl/cpp/wire/wire_coding_traits.h

@@ -80,7 +80,7 @@ void WireCheckPadding(WireDecoder* decoder, WirePosition position, MaskType mask
 
 template <typename T, bool IsRecursive>
 struct WireCodingTraits<T, WireCodingConstraintEmpty, IsRecursive,
-                        typename std::enable_if<IsPrimitive<T>::value>::type> {
+                        std::enable_if_t<IsPrimitive<T>::value>> {
   static constexpr size_t inline_size = sizeof(T);
   static constexpr bool is_memcpy_compatible = true;
 
@@ -104,7 +104,7 @@ struct WireCodingTraits<bool, WireCodingConstraintEmpty, IsRecursive> {
   static void Decode(WireDecoder* decoder, WirePosition position,
                      RecursionDepth<IsRecursive> recursion_depth) {
     uint8_t uintval = *position.As<uint8_t>();
-    if (unlikely(!(uintval == 0 || uintval == 1))) {
+    if (unlikely(uintval != 0 && uintval != 1)) {
       decoder->SetError(kCodingErrorInvalidBoolean);
       return;
     }
@@ -200,7 +200,7 @@ struct VectorCodingTraitHelper {
         DecodePrework(decoder, position, Constraint::is_optional, Constraint::limit)) {
       return;
     }
-    RecursionDepth inner_depth = recursion_depth.Add(decoder, 1);
+    RecursionDepth<IsRecursive> inner_depth = recursion_depth.Add(decoder, 1);
     if (!inner_depth.IsValid()) {
       return;
     }
@@ -341,7 +341,7 @@ struct WireCodingTraits<fidl::Array<T, N>, Constraint, IsRecursive> {
 #ifdef __Fuchsia__
 template <typename T, typename Constraint, bool IsRecursive>
 struct WireCodingTraits<T, Constraint, IsRecursive,
-                        typename std::enable_if<std::is_base_of<zx::object_base, T>::value>::type> {
+                        std::enable_if_t<std::is_base_of_v<zx::object_base, T>>> {
   static constexpr size_t inline_size = sizeof(zx_handle_t);
   static constexpr bool is_memcpy_compatible = false;
 

sdk/lib/fit-promise/fit-promise.api

@@ -1,6 +1,6 @@
 {
   "pkg/fit-promise/include/lib/fpromise/barrier.h": "165eaf8820b9055c94adc5199c9a496d",
-  "pkg/fit-promise/include/lib/fpromise/bridge.h": "5261dd8f50f207091d4d3cf3cc079c01",
+  "pkg/fit-promise/include/lib/fpromise/bridge.h": "092502f25421c313acba8fd7aeda3f14",
   "pkg/fit-promise/include/lib/fpromise/bridge_internal.h": "7f17672771d4eaebe75c5e4d9a3e216a",
   "pkg/fit-promise/include/lib/fpromise/promise.h": "0a5b184d842ff4d8cf3110372e8a0dfa",
   "pkg/fit-promise/include/lib/fpromise/promise_internal.h": "ebb8a10a0da343651d1903a2c99954c3",

sdk/lib/fit-promise/include/lib/fpromise/bridge.h

@@ -161,6 +161,12 @@ class bridge final {
   consumer_type consumer;
 };
 
+// This suppresses the '-Wctad-maybe-unsupported' compiler warning when CTAD is used.
+//
+// See https://github.com/llvm/llvm-project/blob/42874f6/libcxx/include/__config#L1259-L1261.
+template <class... Tag>
+bridge(typename Tag::__allow_ctad...) -> bridge<Tag...>;
+
 // Provides a result upon completion of an asynchronous task.
 //
 // Instances of this class have single-ownership of a unique capability for

sdk/lib/fit-promise/tests/BUILD.gn

@@ -37,16 +37,21 @@ test("fit-promise-tests") {
     "//sdk/lib/fit-promise",
     "//zircon/system/ulib/zxtest",
   ]
-  configs += [ ":shadow" ]
+  configs += [ ":sdk" ]
   if (is_fuchsia) {
     deps += [ "//sdk/lib/fdio" ]
   }
 }
 
-config("shadow") {
-  # chromium uses this library, and enables the following flag,
-  # so these tests should work with this flag enabled
-  cflags_cc = [ "-Wshadow" ]
+# chromium uses this library, and enables the following flags, so these tests should work with these
+# flags enabled.
+#
+# TODO(fxbug.dev/120888): Remove this when a central definition of SDK warnings exists.
+config("sdk") {
+  cflags_cc = [
+    "-Wctad-maybe-unsupported",
+    "-Wshadow",
+  ]
 }
 
 fuchsia_unittest_package("fit-promise-test-pkg") {

sdk/lib/fit/test/BUILD.gn

@@ -28,7 +28,7 @@ test("fit-unittest") {
     "//sdk/lib/fit",
     "//zircon/system/ulib/zxtest",
   ]
-  configs += [ ":shadow" ]
+  configs += [ ":sdk" ]
   if (is_fuchsia) {
     deps += [ "//sdk/lib/fdio" ]
   }
@@ -60,16 +60,21 @@ test("fit") {
     "//sdk/lib/fit",
     "//zircon/system/ulib/zxtest",
   ]
-  configs += [ ":shadow" ]
+  configs += [ ":sdk" ]
   if (is_fuchsia) {
     deps += [ "//sdk/lib/fdio" ]
   }
 }
 
-config("shadow") {
-  # chromium uses this library, and enables the following flag,
-  # so these tests should work with this flag enabled
-  cflags_cc = [ "-Wshadow" ]
+# chromium uses this library, and enables the following flags, so these tests should work with these
+# flags enabled.
+#
+# TODO(fxbug.dev/120888): Remove this when a central definition of SDK warnings exists.
+config("sdk") {
+  cflags_cc = [
+    "-Wctad-maybe-unsupported",
+    "-Wshadow",
+  ]
 }
 
 fuchsia_unittest_package("fit-test-pkg") {

src/lib/fidl/cpp/fidl_cpp_natural_ostream.api

@@ -1,3 +1,3 @@
 {
-  "pkg/fidl_cpp_natural_ostream/include/lib/fidl/cpp/natural_ostream.h": "8ac5e357f4a25064556cede9269e8892"
+  "pkg/fidl_cpp_natural_ostream/include/lib/fidl/cpp/natural_ostream.h": "df2ba72ab56b91148d648d5a91c11f1c"
 }

src/lib/fidl/cpp/include/lib/fidl/cpp/natural_ostream.h

@@ -33,6 +33,9 @@ struct Formatted {
   const T& value;
 };
 
+template <typename T>
+Formatted(const T& v) -> Formatted<T>;
+
 template <typename T, typename = void>
 struct Formatter;
 
@@ -92,9 +95,8 @@ struct Formatter<std::optional<std::string>> {
   static std::ostream& Format(std::ostream& os, const std::optional<std::string>& value) {
     if (value.has_value()) {
       return Formatter<std::string>::Format(os, value.value());
-    } else {
-      return os << "null";
     }
+    return os << "null";
   }
 };
 
@@ -182,9 +184,8 @@ struct Formatter<std::optional<std::vector<T>>> {
   static std::ostream& Format(std::ostream& os, const std::optional<std::vector<T>>& value) {
     if (value.has_value()) {
       return Formatter<std::vector<T>>::Format(os, value.value());
-    } else {
-      return os << "null";
     }
+    return os << "null";
   }
 };
 
@@ -205,9 +206,8 @@ struct Formatter<std::optional<T>> {
   static std::ostream& Format(std::ostream& os, const std::optional<T>& value) {
     if (value.has_value()) {
       return Formatter<T>::Format(os, value.value());
-    } else {
-      return os << "null";
     }
+    return os << "null";
   }
 };
 
@@ -216,9 +216,8 @@ struct Formatter<fidl::Box<T>> {
   static std::ostream& Format(std::ostream& os, const fidl::Box<T>& value) {
     if (value) {
       return Formatter<T>::Format(os, *value);
-    } else {
-      return os << "null";
     }
+    return os << "null";
   }
 };