[NFC] Drop Some Superfluous Null Signature Guards

Author: CodaFi

lib/AST/ASTContext.cpp

@@ -913,7 +913,6 @@ static VarDecl *getPointeeProperty(VarDecl *&cache,
   NominalTypeDecl *nominal = (ctx.*getNominal)();
   if (!nominal) return nullptr;
   auto sig = nominal->getGenericSignature();
-  if (!sig) return nullptr;
   if (sig.getGenericParams().size() != 1) return nullptr;
 
   // There must be a property named "pointee".

lib/AST/Attr.cpp

@@ -945,10 +945,7 @@ bool DeclAttribute::printImpl(ASTPrinter &Printer, const PrintOptions &Options,
     if (target)
       Printer << "target: " << target << ", ";
     SmallVector<Requirement, 4> requirementsScratch;
-    ArrayRef<Requirement> requirements;
-    if (auto sig = attr->getSpecializedSignature())
-      requirements = sig.getRequirements();
-
+    auto requirements = attr->getSpecializedSignature().getRequirements();
     auto *FnDecl = dyn_cast_or_null<AbstractFunctionDecl>(D);
     if (FnDecl && FnDecl->getGenericSignature()) {
       auto genericSig = FnDecl->getGenericSignature();

lib/AST/GenericSignatureBuilder.cpp

@@ -5298,12 +5298,8 @@ class GenericSignatureBuilder::InferRequirementsWalker : public TypeWalker {
     // Infer from generic typealiases.
     if (auto TypeAlias = dyn_cast<TypeAliasType>(ty.getPointer())) {
       auto decl = TypeAlias->getDecl();
-      auto genericSig = decl->getGenericSignature();
-      if (!genericSig)
-        return Action::Continue;
-
       auto subMap = TypeAlias->getSubstitutionMap();
-      for (const auto &rawReq : genericSig.getRequirements()) {
+      for (const auto &rawReq : decl->getGenericSignature().getRequirements()) {
         if (auto req = rawReq.subst(subMap))
           Builder.addRequirement(*req, source, nullptr);
       }
@@ -8078,8 +8074,6 @@ void GenericSignatureBuilder::dump(llvm::raw_ostream &out) {
 }
 
 void GenericSignatureBuilder::addGenericSignature(GenericSignature sig) {
-  if (!sig) return;
-
   for (auto param : sig.getGenericParams())
     addGenericParameter(param);
 
@@ -8605,15 +8599,12 @@ AbstractGenericSignatureRequest::evaluate(
   // If there are no added requirements, we can form the signature directly
   // with the added parameters.
   if (addedRequirements.empty()) {
-    ArrayRef<Requirement> requirements;
-    if (baseSignature) {
-      addedParameters.insert(addedParameters.begin(),
-                             baseSignature.getGenericParams().begin(),
-                             baseSignature.getGenericParams().end());
-      requirements = baseSignature.getRequirements();
-    }
+    addedParameters.insert(addedParameters.begin(),
+                           baseSignature.getGenericParams().begin(),
+                           baseSignature.getGenericParams().end());
 
-    return GenericSignature::get(addedParameters, requirements);
+    return GenericSignature::get(addedParameters,
+                                 baseSignature.getRequirements());
   }
 
   // If the request is non-canonical, we won't need to build our own

lib/SILGen/SILGenLazyConformance.cpp

@@ -324,11 +324,9 @@ void SILGenModule::emitLazyConformancesForFunction(SILFunction *F) {
 void SILGenModule::emitLazyConformancesForType(NominalTypeDecl *NTD) {
   auto genericSig = NTD->getGenericSignature();
 
-  if (genericSig) {
-    for (auto reqt : genericSig.getRequirements()) {
-      if (reqt.getKind() != RequirementKind::Layout)
-        useConformancesFromType(reqt.getSecondType()->getCanonicalType());
-    }
+  for (auto reqt : genericSig.getRequirements()) {
+    if (reqt.getKind() != RequirementKind::Layout)
+      useConformancesFromType(reqt.getSecondType()->getCanonicalType());
   }
 
   if (auto *ED = dyn_cast<EnumDecl>(NTD)) {

lib/SILOptimizer/Mandatory/Differentiation.cpp

@@ -203,8 +203,6 @@ static bool diagnoseUnsatisfiedRequirements(ADContext &context,
     return false;
 
   // If there are no derivative requirements, return false.
-  if (!derivativeGenSig)
-    return false;
   auto requirements = derivativeGenSig.getRequirements();
   if (requirements.empty())
     return false;

lib/SILOptimizer/Utils/Generics.cpp

@@ -1570,9 +1570,8 @@ void FunctionSignaturePartialSpecializer::addCallerRequirements() {
 
 /// Add requirements from the callee's signature.
 void FunctionSignaturePartialSpecializer::addCalleeRequirements() {
-  if (CalleeGenericSig)
-    addRequirements(CalleeGenericSig.getRequirements(),
-                    CalleeInterfaceToSpecializedInterfaceMap);
+  addRequirements(CalleeGenericSig.getRequirements(),
+                  CalleeInterfaceToSpecializedInterfaceMap);
 }
 
 std::pair<GenericEnvironment *, GenericSignature>

lib/Sema/CSSimplify.cpp

@@ -9048,13 +9048,11 @@ ConstraintSystem::simplifyOpaqueUnderlyingTypeConstraint(Type type1, Type type2,
                                   replacements);
   assert(underlyingTyVar);
 
-  if (auto dcSig = DC->getGenericSignatureOfContext()) {
-    for (auto param : dcSig.getGenericParams()) {
-      addConstraint(ConstraintKind::Bind,
-                    openType(param, replacements),
-                    DC->mapTypeIntoContext(param),
-                    locator);
-    }
+  for (auto param : DC->getGenericSignatureOfContext().getGenericParams()) {
+    addConstraint(ConstraintKind::Bind,
+                  openType(param, replacements),
+                  DC->mapTypeIntoContext(param),
+                  locator);
   }
 
   addConstraint(ConstraintKind::Equal, type1, underlyingTyVar, locator);

lib/Sema/ConstraintSystem.cpp

@@ -1402,11 +1402,7 @@ static void bindArchetypesFromContext(
       continue;
     }
 
-    // If it's not generic, there's nothing to do.
     auto genericSig = parentDC->getGenericSignatureOfContext();
-    if (!genericSig)
-      break;
-
     for (auto *paramTy : genericSig.getGenericParams()) {
       Type contextTy = cs.DC->mapTypeIntoContext(paramTy);
       bindPrimaryArchetype(paramTy, contextTy);

lib/Sema/TypeCheckEffects.cpp

@@ -112,12 +112,10 @@ PolymorphicEffectKindRequest::evaluate(Evaluator &evaluator,
     return PolymorphicEffectKind::Always;
   }
 
-  if (auto genericSig = decl->getGenericSignature()) {
-    for (auto req : genericSig.getRequirements()) {
-      if (req.getKind() == RequirementKind::Conformance) {
-        if (req.getProtocolDecl()->hasPolymorphicEffect(kind)) {
-          return PolymorphicEffectKind::ByConformance;
-        }
+  for (auto req : decl->getGenericSignature().getRequirements()) {
+    if (req.getKind() == RequirementKind::Conformance) {
+      if (req.getProtocolDecl()->hasPolymorphicEffect(kind)) {
+        return PolymorphicEffectKind::ByConformance;
       }
     }
   }

lib/Sema/TypeCheckProtocol.cpp

@@ -3703,9 +3703,6 @@ static bool hasSelfSameTypeConstraint(const ValueDecl *req) {
     return false;
 
   const auto genericSig = genCtx->getGenericSignature();
-  if (!genericSig)
-    return false;
-
   const auto selfTy = proto->getSelfInterfaceType();
   for (const auto &constr : genericSig.getRequirements()) {
     if (constr.getKind() != RequirementKind::SameType)
@@ -3728,7 +3725,6 @@ static Optional<std::pair<RequirementRepr *, Requirement>>
 getAdopteeSelfSameTypeConstraint(ClassDecl *selfClass, ValueDecl *witness) {
   auto genericSig =
     witness->getInnermostDeclContext()->getGenericSignatureOfContext();
-  if (!genericSig) return None;
 
   // First, search for any bogus requirements.
   auto it = llvm::find_if(genericSig.getRequirements(),