Merge pull request #71352 from slavapestov/remove-redundant-requirements

Remove -warn-redundant-requirements flag

Author: slavapestov

include/swift/AST/ASTContext.h

@@ -20,7 +20,6 @@
 #include "swift/AST/ASTAllocated.h"
 #include "swift/AST/Availability.h"
 #include "swift/AST/Evaluator.h"
-#include "swift/AST/GenericSignature.h"
 #include "swift/AST/Identifier.h"
 #include "swift/AST/Import.h"
 #include "swift/AST/SILOptions.h"
@@ -87,6 +86,7 @@ namespace swift {
   class ForeignRepresentationInfo;
   class FuncDecl;
   class GenericContext;
+  class GenericSignature;
   class InFlightDiagnostic;
   class IterableDeclContext;
   class LazyContextData;

include/swift/AST/Attr.h

@@ -27,7 +27,6 @@
 #include "swift/AST/MacroDeclaration.h"
 #include "swift/AST/Ownership.h"
 #include "swift/AST/PlatformKind.h"
-#include "swift/AST/Requirement.h"
 #include "swift/AST/StorageImpl.h"
 #include "swift/Basic/Debug.h"
 #include "swift/Basic/EnumTraits.h"

include/swift/AST/DiagnosticsSema.def

@@ -3194,8 +3194,6 @@ ERROR(recursive_superclass_constraint,none,
       "superclass constraint %0 : %1 is recursive", (Type, Type))
 ERROR(requires_same_concrete_type,none,
       "generic signature requires types %0 and %1 to be the same", (Type, Type))
-WARNING(redundant_conformance_constraint,none,
-        "redundant conformance constraint %0 : %1", (Type, Type))
 
 WARNING(missing_protocol_refinement, none,
         "protocol %0 should be declared to refine %1 due to a same-type constraint on 'Self'",
@@ -3204,17 +3202,9 @@ WARNING(missing_protocol_refinement, none,
 ERROR(requirement_conflict,none,
       "no type for %0 can satisfy both %1",
       (Type, StringRef))
-WARNING(redundant_same_type_to_concrete,none,
-        "redundant same-type constraint %0 == %1", (Type, Type))
 ERROR(conflicting_superclass_constraints,none,
       "type %0 cannot be a subclass of both %1 and %2",
       (Type, Type, Type))
-WARNING(redundant_superclass_constraint,none,
-        "redundant superclass constraint %0 : %1", (Type, Type))
-
-WARNING(redundant_layout_constraint,none,
-        "redundant constraint %0 : %1",
-        (Type, LayoutConstraint))
 
 WARNING(redundant_same_type_constraint,none,
         "redundant same-type constraint %0 == %1", (Type, Type))
@@ -7578,8 +7568,6 @@ ERROR(inverse_but_also_conforms, none,
 ERROR(inverse_generic_but_also_conforms, none,
       "%0 required to be '%1' but is marked with '~%1'",
       (Type, StringRef))
-WARNING(redundant_inverse_constraint,none,
-        "redundant constraint %0 : '~%1'", (Type, StringRef))
 ERROR(inverse_on_class, none,
       "classes cannot be '~%0'",
       (StringRef))

include/swift/AST/ProtocolConformanceRef.h

@@ -17,7 +17,6 @@
 #define SWIFT_AST_PROTOCOLCONFORMANCEREF_H
 
 #include "swift/AST/ProtocolConformanceRef.h"
-#include "swift/AST/Requirement.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/TypeAlignments.h"
 #include "swift/Basic/Debug.h"
@@ -36,6 +35,7 @@ class BuiltinProtocolConformance;
 class ConcreteDeclRef;
 class PackConformance;
 class ProtocolConformance;
+class Requirement;
 enum class EffectKind : uint8_t;
 
 /// A ProtocolConformanceRef is a handle to a protocol conformance which

include/swift/AST/Requirement.h

@@ -233,24 +233,11 @@ CheckRequirementsResult checkRequirements(
 /// A requirement as written in source, together with a source location. See
 /// ProtocolDecl::getStructuralRequirements().
 struct StructuralRequirement {
-  /// The actual requirement, where the types were resolved with the
-  /// 'Structural' type resolution stage.
+  /// A requirement with resolved in the structural resolution stage.
   Requirement req;
 
-  /// The source location where the requirement is written, used for redundancy
-  /// and conflict diagnostics.
+  /// The source location where the requirement is written, for diagnostics.
   SourceLoc loc;
-
-  /// A flag indicating whether the requirement was inferred from the
-  /// application of a type constructor. Also used for diagnostics, because
-  /// an inferred requirement made redundant by an explicit requirement is not
-  /// diagnosed as redundant, since we want to give users the option of
-  /// spelling out these requirements explicitly.
-  bool inferred = false;
-
-  /// A flag indicating whether this requirement was produced via the expansion
-  /// of default conformances to invertible protocols.
-  bool fromDefault = false;
 };
 
 /// An "anti-conformance" requirement `Subject: ~Protocol`.

include/swift/AST/Types.h

@@ -27,7 +27,6 @@
 #include "swift/AST/KnownProtocols.h"
 #include "swift/AST/Ownership.h"
 #include "swift/AST/ProtocolConformanceRef.h"
-#include "swift/AST/Requirement.h"
 #include "swift/AST/SubstitutionMap.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/TypeAlignments.h"

include/swift/Basic/LangOptions.h

@@ -553,9 +553,6 @@ namespace swift {
     /// rewrite system.
     bool EnableRequirementMachineOpaqueArchetypes = false;
 
-    /// Enable warnings for redundant requirements in generic signatures.
-    bool WarnRedundantRequirements = false;
-
     /// Enable experimental associated type inference improvements.
     bool EnableExperimentalAssociatedTypeInference = false;
 

include/swift/Option/FrontendOptions.td

@@ -425,9 +425,6 @@ def disable_requirement_machine_reuse : Flag<["-"], "disable-requirement-machine
 def enable_requirement_machine_opaque_archetypes : Flag<["-"], "enable-requirement-machine-opaque-archetypes">,
   HelpText<"Enable more correct opaque archetype support, which is off by default because it might fail to produce a convergent rewrite system">;
 
-def warn_redundant_requirements : Flag<["-"], "warn-redundant-requirements">,
-  HelpText<"Emit warnings for redundant requirements in generic signatures">;
-
 def dump_type_witness_systems : Flag<["-"], "dump-type-witness-systems">,
   HelpText<"Enables dumping type witness systems from associated type inference">;
 

lib/AST/Requirement.cpp

@@ -362,10 +362,7 @@ void InverseRequirement::expandDefaults(
 
       auto protoTy = proto->getDeclaredInterfaceType();
       result.push_back({{RequirementKind::Conformance, gp, protoTy},
-                        SourceLoc(),
-                        /*inferred=*/true,
-                        /*default=*/true,
-                       });
+                        SourceLoc()});
     }
   }
 }

lib/AST/RequirementMachine/ConcreteContraction.cpp

@@ -691,32 +691,15 @@ bool ConcreteContraction::performConcreteContraction(
     // requirement where the left hand side is not a type parameter.
     SmallVector<Requirement, 4> reqs;
     SmallVector<InverseRequirement, 4> ignoreInverses;
-    if (req.inferred) {
-      // Discard errors from desugaring a substituted requirement that
-      // was inferred. For example, if we have something like
-      //
-      //   <T, U where T == Int, U == Set<T>>
-      //
-      // The inferred requirement 'T : Hashable' from 'Set<>' will
-      // be substituted with 'T == Int' to get 'Int : Hashable'.
-      //
-      // Desugaring will diagnose a redundant conformance requirement,
-      // but we want to ignore that, since the user did not explicitly
-      // write 'Int : Hashable' (or 'T : Hashable') anywhere.
-      SmallVector<RequirementError, 4> discardErrors;
-      desugarRequirement(substReq, SourceLoc(), reqs,
-                         ignoreInverses, discardErrors);
-    } else {
-      desugarRequirement(substReq, req.loc, reqs, ignoreInverses, errors);
-    }
+    desugarRequirement(substReq, req.loc, reqs, ignoreInverses, errors);
 
     for (auto desugaredReq : reqs) {
       if (Debug) {
         llvm::dbgs() << "@@ Desugared requirement: ";
         desugaredReq.dump(llvm::dbgs());
         llvm::dbgs() << "\n";
       }
-      result.push_back({desugaredReq, req.loc, req.inferred});
+      result.push_back({desugaredReq, req.loc});
     }
 
     if (preserveSameTypeRequirement(req.req) &&
@@ -730,7 +713,7 @@ bool ConcreteContraction::performConcreteContraction(
 
       // Make the duplicated requirement 'inferred' so that we don't diagnose
       // it as redundant.
-      result.push_back({req.req, SourceLoc(), /*inferred=*/true});
+      result.push_back({req.req, SourceLoc()});
     }
   }