[Archetype builder] Remove RequirementSource::Kind::OuterScope.

"Explicit" covers everything we need now. NFC

Author: DougGregor

include/swift/AST/ArchetypeBuilder.h

@@ -83,11 +83,6 @@ class RequirementSource {
     ///
     /// These are dropped when building the GenericSignature.
     Inherited,
-
-    /// The requirement came from an outer scope.
-    /// FIXME: eliminate this in favor of keeping requirement sources in 
-    /// GenericSignatures, at least non-canonical ones?
-    OuterScope,
   };
 
   RequirementSource(Kind kind, SourceLoc loc) : StoredKind(kind), Loc(loc) { }
@@ -252,13 +247,8 @@ class ArchetypeBuilder {
   void addRequirement(const Requirement &req, RequirementSource source);
 
   /// \brief Add all of a generic signature's parameters and requirements.
-  ///
-  /// FIXME: Requirements from the generic signature are treated as coming from
-  /// an outer scope. Setting \c treatRequirementsAsExplicit to true disables
-  /// this behavior.
   void addGenericSignature(GenericSignature *sig,
-                           GenericEnvironment *genericEnv,
-                           bool treatRequirementsAsExplicit = false);
+                           GenericEnvironment *genericEnv);
 
   /// \brief Build the generic signature.
   GenericSignature *getGenericSignature();

lib/AST/ASTContext.cpp

@@ -1263,8 +1263,7 @@ ArchetypeBuilder *ASTContext::getOrCreateArchetypeBuilder(
 
   // Create a new archetype builder with the given signature.
   auto builder = new ArchetypeBuilder(*mod, Diags);
-  builder->addGenericSignature(sig, nullptr,
-                               /*treatRequirementsAsExplicit=*/true);
+  builder->addGenericSignature(sig, nullptr);
 
   // Store this archetype builder.
   Impl.ArchetypeBuilders[{sig, mod}]

lib/AST/ArchetypeBuilder.cpp

@@ -61,10 +61,6 @@ void RequirementSource::dump(llvm::raw_ostream &out,
     out << "inferred";
     break;
 
-  case OuterScope:
-    out << "outer";
-    break;
-
   case Inherited:
     out << "inherited";
     break;
@@ -685,7 +681,6 @@ ArchetypeBuilder::PotentialArchetype::getType(ArchetypeBuilder &builder) {
     switch (conforms.second.getKind()) {
     case RequirementSource::Explicit:
     case RequirementSource::Inferred:
-    case RequirementSource::OuterScope:
     case RequirementSource::Protocol:
     case RequirementSource::Redundant:
       Protos.push_back(conforms.first);
@@ -2010,14 +2005,10 @@ ArchetypeBuilder::mapTypeOutOfContext(ModuleDecl *M,
 }
 
 void ArchetypeBuilder::addGenericSignature(GenericSignature *sig,
-                                           GenericEnvironment *env,
-                                           bool treatRequirementsAsExplicit) {
+                                           GenericEnvironment *env) {
   if (!sig) return;
 
-  RequirementSource::Kind sourceKind = treatRequirementsAsExplicit
-    ? RequirementSource::Explicit
-    : RequirementSource::OuterScope;
-  
+  RequirementSource::Kind sourceKind = RequirementSource::Explicit;
   for (auto param : sig->getGenericParams()) {
     addGenericParameter(param);
 
@@ -2057,7 +2048,6 @@ static void collectRequirements(ArchetypeBuilder &builder,
     switch (source.getKind()) {
     case RequirementSource::Explicit:
     case RequirementSource::Inferred:
-    case RequirementSource::OuterScope:
       // The requirement was explicit and required, keep it.
       break;
 

test/Generics/requirement_inference.swift

@@ -57,7 +57,7 @@ class Fox : P1 {
 class Box<T : Fox> {
 // CHECK-LABEL: .unpack@
 // CHECK-NEXT: Requirements:
-// CHECK-NEXT:   T : Fox [outer]
+// CHECK-NEXT:   T : Fox [explicit]
   func unpack(_ x: X1<T>) {}
 }
 

test/SILGen/generic_witness.swift

@@ -50,7 +50,7 @@ struct Canvas<I : Ink> where I.Paint : Pen {
 
 extension Canvas : Medium {}
 
-// CHECK-LABEL: sil hidden [transparent] [thunk] @_TTWuRx15generic_witness3Inkwx5PaintS_3PenrGVS_6Canvasx_S_6MediumS_FS4_4drawuRd__S_6Pencilwd__6StrokezWx7TextureS1__rfT5paintWxS7_S1__6pencilqd___T_ : $@convention(witness_method) <τ_0_0 where τ_0_0 : Ink, τ_0_0.Paint : Pen><τ_1_0 where τ_1_0 : Pencil, τ_0_0.Paint == τ_1_0.Stroke> (@in τ_0_0.Paint, @in τ_1_0, @in_guaranteed Canvas<τ_0_0>) -> ()
-// CHECK: [[FN:%.*]] = function_ref @_TFV15generic_witness6Canvas4drawuRd__S_6Pencilwx5Paintzwd__6StrokerfT5paintwxS2_6pencilqd___T_ : $@convention(method) <τ_0_0 where τ_0_0 : Ink, τ_0_0.Paint : Pen><τ_1_0 where τ_1_0 : Pencil, τ_0_0.Paint == τ_1_0.Stroke> (@in τ_0_0.Paint, @in τ_1_0, Canvas<τ_0_0>) -> ()
-// CHECK: apply [[FN]]<τ_0_0, τ_1_0, τ_0_0.Paint>({{.*}}) : $@convention(method) <τ_0_0 where τ_0_0 : Ink, τ_0_0.Paint : Pen><τ_1_0 where τ_1_0 : Pencil, τ_0_0.Paint == τ_1_0.Stroke> (@in τ_0_0.Paint, @in τ_1_0, Canvas<τ_0_0>) -> ()
+// CHECK-LABEL: sil hidden [transparent] [thunk] @_TTWuRx15generic_witness3Inkwx5PaintS_3PenrGVS_6Canvasx_S_6MediumS_FS4_4drawuRd__S_6Pencilwd__6StrokezWx7TextureS1__rfT5paintWxS7_S1__6pencilqd___T_ : $@convention(witness_method) <τ_0_0 where τ_0_0 : Ink><τ_1_0 where τ_1_0 : Pencil, τ_0_0.Paint == τ_1_0.Stroke> (@in τ_0_0.Paint, @in τ_1_0, @in_guaranteed Canvas<τ_0_0>) -> ()
+// CHECK: [[FN:%.*]] = function_ref @_TFV15generic_witness6Canvas4drawuRd__S_6Pencilwx5Paintzwd__6StrokerfT5paintwxS2_6pencilqd___T_ : $@convention(method) <τ_0_0 where τ_0_0 : Ink><τ_1_0 where τ_1_0 : Pencil, τ_0_0.Paint == τ_1_0.Stroke> (@in τ_0_0.Paint, @in τ_1_0, Canvas<τ_0_0>) -> ()
+// CHECK: apply [[FN]]<τ_0_0, τ_1_0>({{.*}}) : $@convention(method) <τ_0_0 where τ_0_0 : Ink><τ_1_0 where τ_1_0 : Pencil, τ_0_0.Paint == τ_1_0.Stroke> (@in τ_0_0.Paint, @in τ_1_0, Canvas<τ_0_0>) -> ()
 // CHECK: }