[NFC] Clean up IRGen generic-requirements collection APIs

Author: rjmccall

lib/IRGen/GenProto.cpp

@@ -3172,7 +3172,7 @@ void EmitPolymorphicArguments::emit(SubstitutionMap subs,
   // For now, treat all archetypes independently.
   enumerateUnfulfilledRequirements([&](GenericRequirement requirement) {
     llvm::Value *requiredValue =
-      emitGenericRequirementFromSubstitutions(IGF, Generics, M,
+      emitGenericRequirementFromSubstitutions(IGF, Generics,
                                               requirement, subs);
     out.add(requiredValue);
   });
@@ -3294,14 +3294,17 @@ NecessaryBindings NecessaryBindings::computeBindings(
 /// that takes the (thick) parent metatype as an argument.
 GenericTypeRequirements::GenericTypeRequirements(IRGenModule &IGM,
                                                  NominalTypeDecl *typeDecl)
-    : TheDecl(typeDecl) {
+  : GenericTypeRequirements(IGM, typeDecl->getGenericSignatureOfContext()) {}
+
+GenericTypeRequirements::GenericTypeRequirements(IRGenModule &IGM,
+                                                 GenericSignature ncGenerics) {
   // We only need to do something here if the declaration context is
   // somehow generic.
-  auto ncGenerics = typeDecl->getGenericSignatureOfContext();
   if (!ncGenerics || ncGenerics->areAllParamsConcrete()) return;
 
   // Construct a representative function type.
   auto generics = ncGenerics.getCanonicalSignature();
+  Generics = generics;
   auto fnType = SILFunctionType::get(generics, SILFunctionType::ExtInfo(),
                                 SILCoroutineKind::None,
                                 /*callee*/ ParameterConvention::Direct_Unowned,
@@ -3345,12 +3348,9 @@ void GenericTypeRequirements::emitInitOfBuffer(IRGenFunction &IGF,
                                                Address buffer) {
   if (Requirements.empty()) return;
 
-  auto generics =
-      TheDecl->getGenericSignatureOfContext().getCanonicalSignature();
-  auto &module = *TheDecl->getParentModule();
   emitInitOfGenericRequirementsBuffer(IGF, Requirements, buffer,
                                       [&](GenericRequirement requirement) {
-    return emitGenericRequirementFromSubstitutions(IGF, generics, module,
+    return emitGenericRequirementFromSubstitutions(IGF, Generics,
                                                    requirement, subs);
   });
 }
@@ -3383,7 +3383,6 @@ void irgen::emitInitOfGenericRequirementsBuffer(IRGenFunction &IGF,
 llvm::Value *
 irgen::emitGenericRequirementFromSubstitutions(IRGenFunction &IGF,
                                                CanGenericSignature generics,
-                                               ModuleDecl &module,
                                                GenericRequirement requirement,
                                                SubstitutionMap subs) {
   CanType depTy = requirement.TypeParameter;

lib/IRGen/GenericArguments.h

@@ -73,10 +73,14 @@ struct GenericArguments {
   }
 
   void collect(IRGenFunction &IGF, CanType type) {
-    auto *decl = type.getNominalOrBoundGenericNominal();
-    GenericTypeRequirements requirements(IGF.IGM, decl);
-
+    auto decl = type.getNominalOrBoundGenericNominal();
     auto subs = type->getContextSubstitutionMap(IGF.IGM.getSwiftModule(), decl);
+    collect(IGF, subs);
+  }
+
+  void collect(IRGenFunction &IGF, SubstitutionMap subs) {
+    GenericTypeRequirements requirements(IGF.IGM, subs.getGenericSignature());
+
     requirements.enumerateFulfillments(
         IGF.IGM, subs,
         [&](unsigned reqtIndex, CanType type, ProtocolConformanceRef conf) {
@@ -87,7 +91,7 @@ struct GenericArguments {
           }
         });
 
-    collectTypes(IGF.IGM, decl);
+    collectTypes(IGF.IGM, requirements);
     assert(Types.size() == Values.size());
   }
 };

lib/IRGen/GenericRequirement.h

@@ -60,7 +60,6 @@ void enumerateGenericSignatureRequirements(CanGenericSignature signature,
 llvm::Value *
 emitGenericRequirementFromSubstitutions(IRGenFunction &IGF,
                                         CanGenericSignature signature,
-                                        ModuleDecl &module,
                                         GenericRequirement requirement,
                                         SubstitutionMap subs);
 
@@ -99,11 +98,12 @@ void bindFromGenericRequirementsBuffer(IRGenFunction &IGF,
 /// root conformances of the context established by the type, again minus
 /// anything fulfillable from its parent type metadata).
 class GenericTypeRequirements {
-  NominalTypeDecl *TheDecl;
   llvm::SmallVector<GenericRequirement, 4> Requirements;
+  CanGenericSignature Generics;
 
 public:
   GenericTypeRequirements(IRGenModule &IGM, NominalTypeDecl *decl);
+  GenericTypeRequirements(IRGenModule &IGM, GenericSignature sig);
 
   /// Return the layout chunks.
   ArrayRef<GenericRequirement> getRequirements() const {

lib/IRGen/IRGenSIL.cpp

@@ -6473,8 +6473,7 @@ void IRGenSILFunction::visitKeyPathInst(swift::KeyPathInst *I) {
       emitInitOfGenericRequirementsBuffer(*this, requirements, argsBuf,
         [&](GenericRequirement reqt) -> llvm::Value * {
           return emitGenericRequirementFromSubstitutions(*this, sig,
-                                           *IGM.getSwiftModule(),
-                                           reqt, subs);
+                                                         reqt, subs);
         });
     }