ClangImporter: Introduce the #ClangDeclarationImport diagnostic group.

The warnings that ClangImporter emits about issues it encounters while
importing declarations from Clang modules should all belong to a diagnostic
group so that users of `-warnings-as-errors` can control their behavior using
the compiler flags introduce with SE-0443. It's especially important that these
diagnostics be controllable since they are often caused by external
dependencies and therefore the developer may not have any control over whether
they are emitted.

The `#ClangDeclarationImport` diagnostic group is intentionally broad so that
developers have a way to control all of these diagnostics with a single
`-Wwarning` flag. I fully expect that we'll introduce finer-grained diagnostic
groups for some of these diagnostics in the future, but those groups should be
hierarchically nested under `#ClangDeclarationImport`, which is supported by
SE-0443.

Resolves rdar://150524204.

Author: tshortli

include/swift/AST/DiagnosticGroups.def

@@ -41,7 +41,7 @@
 GROUP(no_group, "")
 
 GROUP(ActorIsolatedCall, "actor-isolated-call")
-GROUP(NonisolatedNonsendingByDefault, "nonisolated-nonsending-by-default")
+GROUP(ClangDeclarationImport, "clang-declaration-import")
 GROUP(ConformanceIsolation, "conformance-isolation")
 GROUP(DeprecatedDeclaration, "deprecated-declaration")
 GROUP(DynamicCallable, "dynamic-callable-requirements")
@@ -52,6 +52,7 @@ GROUP(IsolatedConformances, "isolated-conformances")
 GROUP(MultipleInheritance, "multiple-inheritance")
 GROUP(MutableGlobalVariable, "mutable-global-variable")
 GROUP(NominalTypes, "nominal-types")
+GROUP(NonisolatedNonsendingByDefault, "nonisolated-nonsending-by-default")
 GROUP(OpaqueTypeInference, "opaque-type-inference")
 GROUP(PreconcurrencyImport, "preconcurrency-import")
 GROUP(PropertyWrappers, "property-wrapper-requirements")

include/swift/AST/DiagnosticsClangImporter.def

@@ -51,10 +51,10 @@ ERROR(emit_pcm_error,Fatal,
 ERROR(dump_pcm_error,Fatal,
    "failed to dump precompiled module '%0'", (StringRef))
 
-WARNING(invalid_swift_name_method,none,
+GROUPED_WARNING(invalid_swift_name_method, ClangDeclarationImport, none,
   "too %select{few|many}0 parameters in swift_name attribute (expected %1; "
   "got %2)", (bool, unsigned, unsigned))
-WARNING(invalid_swift_name_for_decl,none,
+GROUPED_WARNING(invalid_swift_name_for_decl, ClangDeclarationImport, none,
   "custom Swift name '%0' ignored because it is not valid for %kindonly1; "
   "imported as %1 instead",
   (StringRef, ValueDecl *))
@@ -67,35 +67,35 @@ ERROR(swift_name_protocol_static, none, "swift_name cannot be used to define "
 ERROR(swift_name_no_prototype, none,
       "swift_name cannot be used on a non-prototyped function declaration", ())
 
-WARNING(inconsistent_swift_name,none,
+GROUPED_WARNING(inconsistent_swift_name, ClangDeclarationImport, none,
         "inconsistent Swift name for Objective-C %select{method|property}0 "
         "'%1' in '%2' (%3 in '%4' vs. %5 in '%6')",
         (bool, StringRef, StringRef, DeclName, StringRef, DeclName,
          StringRef))
 
-WARNING(swift_name_circular_context_import,none,
+GROUPED_WARNING(swift_name_circular_context_import, ClangDeclarationImport, none,
         "cycle detected while resolving '%0' in swift_name attribute for '%1'",
         (StringRef, StringRef))
 NOTE(swift_name_circular_context_import_other,none,
      "while resolving '%0' in swift_name attribute for '%1'",
      (StringRef, StringRef))
 
-WARNING(unresolvable_clang_decl,none,
+GROUPED_WARNING(unresolvable_clang_decl, ClangDeclarationImport, none,
         "imported declaration '%0' could not be mapped to '%1'",
         (StringRef, StringRef))
 
 NOTE(unresolvable_clang_decl_is_a_framework_bug,none,
      "please report this issue to the owners of '%0'",
      (StringRef))
 
-WARNING(clang_swift_attr_unhandled,none,
+GROUPED_WARNING(clang_swift_attr_unhandled, ClangDeclarationImport, none,
         "ignoring unknown Swift attribute or modifier '%0'", (StringRef))
 
-WARNING(clang_error_code_must_be_sendable,none,
+GROUPED_WARNING(clang_error_code_must_be_sendable, ClangDeclarationImport, none,
         "cannot make error code type '%0' non-sendable because Swift errors "
         "are always sendable", (StringRef))
 
-WARNING(clang_ignored_sendable_attr,none,
+GROUPED_WARNING(clang_ignored_sendable_attr, ClangDeclarationImport, none,
         "cannot make type %0 sendable because '@Sendable' and '& Sendable' "
         "cannot be added to it",
         (Type))
@@ -108,18 +108,18 @@ WARNING(implicit_bridging_header_imported_from_module,none,
         "is deprecated and will be removed in a later version of Swift",
         (StringRef, Identifier))
 
-WARNING(import_multiple_mainactor_attr,none,
+GROUPED_WARNING(import_multiple_mainactor_attr, ClangDeclarationImport, none,
       "this attribute for global actor '%0' is invalid; the declaration already has attribute for global actor '%1'",
       (StringRef, StringRef))
 
-WARNING(contradicting_mutation_attrs,none,
+GROUPED_WARNING(contradicting_mutation_attrs, ClangDeclarationImport, none,
         "attribute '%0' is ignored when combined with attribute '%1'",
         (StringRef, StringRef))
 
-WARNING(nonmutating_without_const,none,
+GROUPED_WARNING(nonmutating_without_const, ClangDeclarationImport, none,
         "attribute 'nonmutating' has no effect on non-const method", ())
 
-WARNING(nonmutating_without_mutable_fields,none,
+GROUPED_WARNING(nonmutating_without_mutable_fields, ClangDeclarationImport, none,
         "attribute 'nonmutating' has no effect without any mutable fields", ())
 
 ERROR(module_map_not_found, none, "module map file '%0' not found", (StringRef))
@@ -135,7 +135,7 @@ WARNING(libstdcxx_modulemap_not_found, none,
         "module map for libstdc++ not found for '%0'; C++ stdlib may be unavailable",
         (StringRef))
 
-WARNING(api_pattern_attr_ignored, none,
+GROUPED_WARNING(api_pattern_attr_ignored, ClangDeclarationImport, none,
         "'%0' Swift attribute ignored on type '%1': type is not copyable or destructible",
         (StringRef, StringRef))
 
@@ -226,7 +226,7 @@ ERROR(private_fileid_attr_repeated, none,
  NOTE(private_fileid_attr_here, none,
      "SWIFT_PRIVATE_FILEID annotation found here", ())
 
- WARNING(private_fileid_attr_format_invalid, none,
+ GROUPED_WARNING(private_fileid_attr_format_invalid, ClangDeclarationImport, none,
      "SWIFT_PRIVATE_FILEID annotation on '%0' does not have a valid file ID",
      (StringRef))
  REMARK(private_fileid_attr_format_specification, none,
@@ -306,12 +306,12 @@ ERROR(returns_retained_or_returns_unretained_for_non_cxx_frt_values, none,
 // TODO: In the next C++ interop version, convert this warning into an error and
 // stop importing unannotated C++ APIs that return SWIFT_SHARED_REFERENCE.
 // rdar://138806722
-WARNING(no_returns_retained_returns_unretained, none,
+GROUPED_WARNING(no_returns_retained_returns_unretained, ClangDeclarationImport, none,
         "%0 should be annotated with either SWIFT_RETURNS_RETAINED or "
         "SWIFT_RETURNS_UNRETAINED as it is returning a SWIFT_SHARED_REFERENCE",
         (const clang::NamedDecl *))
 
-WARNING(returns_retained_returns_unretained_on_overloaded_operator, none,
+GROUPED_WARNING(returns_retained_returns_unretained_on_overloaded_operator,  ClangDeclarationImport, none,
         "SWIFT_RETURNS_RETAINED and SWIFT_RETURNS_UNRETAINED is not supported "
         "yet for overloaded C++ %0. Overloaded C++ operators always "
         "return "
@@ -322,7 +322,7 @@ WARNING(returns_retained_returns_unretained_on_overloaded_operator, none,
 // stop importing C++ types that inherit from SWIFT_SHARED_REFERENCE if the
 // Swift compiler cannot find unique retain/release functions.
 // rdar://145194375
-WARNING(cant_infer_frt_in_cxx_inheritance, none,
+GROUPED_WARNING(cant_infer_frt_in_cxx_inheritance, ClangDeclarationImport, none,
         "unable to infer SWIFT_SHARED_REFERENCE for %0, although one of its "
         "transitive base types is marked as SWIFT_SHARED_REFERENCE",
         (const clang::NamedDecl *))
@@ -355,8 +355,12 @@ NOTE(forward_declared_protocol_clashes_with_imported_objc_Swift_protocol, none,
      "its name conflicts with a %1 in module %2",
      (const clang::NamedDecl*, StringRef, StringRef))
 
-WARNING(return_escapable_with_lifetimebound, none, "the returned type '%0' is annotated as escapable; it cannot have lifetime dependencies", (StringRef))
-WARNING(return_nonescapable_without_lifetimebound, none, "the returned type '%0' is annotated as non-escapable; its lifetime dependencies must be annotated", (StringRef))
+GROUPED_WARNING(return_escapable_with_lifetimebound,  ClangDeclarationImport, none,
+     "the returned type '%0' is annotated as escapable; it cannot have lifetime dependencies",
+     (StringRef))
+GROUPED_WARNING(return_nonescapable_without_lifetimebound, ClangDeclarationImport, none,
+     "the returned type '%0' is annotated as non-escapable; its lifetime dependencies must be annotated",
+     (StringRef))
 
 ERROR(unknown_template_parameter,none,
   "template parameter '%0' does not exist", (StringRef))

test/ClangImporter/Inputs/custom-modules/ImportAsMember.h

@@ -70,8 +70,8 @@ typedef float MNInnerFloat __attribute__((swift_name("IAMMultipleNested.Inner"))
 
 typedef int IAMBadInnerInt
     __attribute__((swift_name("IAMNonexistent.Inner")));
-// CHECK: ImportAsMember.h:[[@LINE-1]]:{{[0-9]+}}: warning: imported declaration 'IAMBadInnerInt' could not be mapped to 'IAMNonexistent.Inner'
-// CHECK: note: please report this issue to the owners of 'ImportAsMember'
+// CHECK: ImportAsMember.h:[[@LINE-1]]:{{[0-9]+}}: warning: imported declaration 'IAMBadInnerInt' could not be mapped to 'IAMNonexistent.Inner' [#ClangDeclarationImport]
+// CHECK: note: please report this issue to the owners of 'ImportAsMember' [#ClangDeclarationImport]
 typedef int IAMBadInnerIntAPINotes;
 // CHECK: ImportAsMember.h:[[@LINE-1]]:{{[0-9]+}}: warning: imported declaration 'IAMBadInnerIntAPINotes' could not be mapped to 'IAMNonexistent.Inner2'
 // CHECK: note: please report this issue to the owners of 'ImportAsMember'

test/ClangImporter/attr-swift_name.swift

@@ -20,19 +20,19 @@ func test(_ i: Int) {
   // We only see these five warnings because Clang can catch the other invalid
   // cases, and marks the attribute as invalid ahead of time.
 
-  // CHECK: warning: too few parameters in swift_name attribute (expected 2; got 1)
+  // CHECK: warning: too few parameters in swift_name attribute (expected 2; got 1) [#ClangDeclarationImport]
   // CHECK: + (instancetype)g:(id)x outParam:(int *)foo SWIFT_NAME(init(g:));
   // CHECK-NOT: warning:
   // CHECK: note: please report this issue to the owners of 'ObjCIRExtras'
   // CHECK-NOT: warning:
 
-  // CHECK: warning: cycle detected while resolving 'CircularName' in swift_name attribute for 'CircularName'
+  // CHECK: warning: cycle detected while resolving 'CircularName' in swift_name attribute for 'CircularName' [#ClangDeclarationImport]
   // CHECK: SWIFT_NAME(CircularName.Inner) @interface CircularName : NSObject @end
   // CHECK-NOT: {{warning|note}}:
   // CHECK: note: please report this issue to the owners of 'ObjCIRExtras'
   // CHECK-NOT: warning:
 
-  // CHECK: warning: cycle detected while resolving 'MutuallyCircularNameB' in swift_name attribute for 'MutuallyCircularNameA'
+  // CHECK: warning: cycle detected while resolving 'MutuallyCircularNameB' in swift_name attribute for 'MutuallyCircularNameA' [#ClangDeclarationImport]
   // CHECK: SWIFT_NAME(MutuallyCircularNameB.Inner) @interface MutuallyCircularNameA : NSObject @end
   // CHECK-NOT: {{warning|note}}:
   // CHECK: note: while resolving 'MutuallyCircularNameA' in swift_name attribute for 'MutuallyCircularNameB'

test/ClangImporter/duplicate_mainactor.swift

@@ -5,6 +5,6 @@
 // REQUIRES: concurrency
 // REQUIRES: objc_interop
 
-// CHECK: DoubleMainActor.h:{{[0-9]+}}:{{[0-9]+}}: warning: this attribute for global actor '@MainActor' is invalid; the declaration already has attribute for global actor '@UIActor'
+// CHECK: DoubleMainActor.h:{{[0-9]+}}:{{[0-9]+}}: warning: this attribute for global actor '@MainActor' is invalid; the declaration already has attribute for global actor '@UIActor' [#ClangDeclarationImport]
 
-protocol P : DoubleMainActor {}
+protocol P : DoubleMainActor {}

test/IDE/print_omit_needless_words.swift

@@ -314,7 +314,7 @@
 // CHECK-OMIT-NEEDLESS-WORDS-NEXT: @available(swift, obsoleted: 3, renamed: "veryCarefullyBurn()")
 // CHECK-OMIT-NEEDLESS-WORDS-NEXT: func veryCarefullyBurnGarbage4DTypeRefMask_t()
 
-// CHECK-OMIT-NEEDLESS-WORDS-DIAGS: inconsistent Swift name for Objective-C property 'conflictingProp1' in 'OMWSub' ('waggleProp1' in 'OMWWaggle' vs. 'wiggleProp1' in 'OMWSuper')
+// CHECK-OMIT-NEEDLESS-WORDS-DIAGS: inconsistent Swift name for Objective-C property 'conflictingProp1' in 'OMWSub' ('waggleProp1' in 'OMWWaggle' vs. 'wiggleProp1' in 'OMWSuper') [#ClangDeclarationImport]
 
 // Don't drop the 'error'.
 // CHECK-ERRORS: func tryAndReturnError(_: ()) throws

test/Interop/Cxx/class/nonescapable-errors.swift

@@ -111,16 +111,16 @@ public func importInvalid(_ x: Invalid) {
 // CHECK: error: a function with a ~Escapable result needs a parameter to depend on
 // CHECK-NO-LIFETIMES: test.swift:11:32: error: a function with a ~Escapable result requires '-enable-experimental-feature LifetimeDependence'
 public func noAnnotations() -> View {
-    // CHECK: nonescapable.h:16:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies
-    // CHECK-NO-LIFETIMES: nonescapable.h:16:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies
+    // CHECK: nonescapable.h:16:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies [#ClangDeclarationImport]
+    // CHECK-NO-LIFETIMES: nonescapable.h:16:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies [#ClangDeclarationImport]
     f(nil)
-    // CHECK: nonescapable.h:20:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies
-    // CHECK-NO-LIFETIMES: nonescapable.h:20:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies
+    // CHECK: nonescapable.h:20:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies [#ClangDeclarationImport]
+    // CHECK-NO-LIFETIMES: nonescapable.h:20:7: warning: the returned type 'Owner' is annotated as escapable; it cannot have lifetime dependencies [#ClangDeclarationImport]
     // No duplicate warning for f2:
     // CHECK-NOT: nonescapable.h:20
     f2(nil, nil)
-    // CHECK: nonescapable.h:24:6: warning: the returned type 'View' is annotated as non-escapable; its lifetime dependencies must be annotated
-    // CHECK-NO-LIFETIMES: nonescapable.h:24:6: warning: the returned type 'View' is annotated as non-escapable; its lifetime dependencies must be annotated
+    // CHECK: nonescapable.h:24:6: warning: the returned type 'View' is annotated as non-escapable; its lifetime dependencies must be annotated [#ClangDeclarationImport]
+    // CHECK-NO-LIFETIMES: nonescapable.h:24:6: warning: the returned type 'View' is annotated as non-escapable; its lifetime dependencies must be annotated [#ClangDeclarationImport]
     // CHECK-NO-LIFETIMES: nonescapable.h:24:6: error: a function with a ~Escapable result requires '-enable-experimental-feature LifetimeDependence'
     g(nil)
     h1(nil)

test/Interop/Cxx/foreign-reference/Inputs/cxx-functions-and-methods-returning-frt.h

@@ -179,7 +179,7 @@ __attribute__((swift_attr("unsafe")));
 
 // C++ APIs returning cxx frts (for testing diagnostics)
 struct StructWithAPIsReturningCxxFrt {
-  static FRTStruct *_Nonnull StaticMethodReturningCxxFrt(); // expected-warning {{'StaticMethodReturningCxxFrt' should be annotated with either SWIFT_RETURNS_RETAINED or SWIFT_RETURNS_UNRETAINED as it is returning a SWIFT_SHARED_REFERENCE}} 
+  static FRTStruct *_Nonnull StaticMethodReturningCxxFrt(); // expected-warning {{'StaticMethodReturningCxxFrt' should be annotated with either SWIFT_RETURNS_RETAINED or SWIFT_RETURNS_UNRETAINED as it is returning a SWIFT_SHARED_REFERENCE}}
   static FRTStruct *_Nonnull StaticMethodReturningCxxFrtWithAnnotation()
       __attribute__((swift_attr("returns_retained")));
 };

userdocs/diagnostics/clang-declaration-import.md

@@ -0,0 +1,17 @@
+# Imported Clang Declaration Warnings (`ClangDeclarationImport`)
+
+
+This diagnostic group covers all warnings related to malformed APIs that are imported into Swift from C, C++, and Obj-C headers.
+
+As one example of a potential malformed API diagnostic, suppose a Clang module dependency contained the following declaration:
+
+```
+typedef int NotificationIdentifier
+    __attribute__((swift_name("Notification.Identifier")))
+```
+
+The Swift compiler would emit the following warning if no type named `Notification` could be found:
+
+```
+warning: imported declaration 'NotificationIdentifier' could not be mapped to 'Notification.Identifier’
+```