[AST] Remove GenericSignature params from GenericEnvironment methods.

The GenericEnvironment stores a signature internally.

include/swift/AST/GenericEnvironment.h

@@ -83,18 +83,16 @@ public:
   /// with contextual types instead of interface types.
   SubstitutionMap
   getSubstitutionMap(ModuleDecl *mod,
-                     GenericSignature *sig,
                      ArrayRef<Substitution> subs) const;
 
   /// Same as above, but updates an existing map.
   void
   getSubstitutionMap(ModuleDecl *mod,
-                     GenericSignature *sig,
                      ArrayRef<Substitution> subs,
                      SubstitutionMap &subMap) const;
 
   ArrayRef<Substitution>
-  getForwardingSubstitutions(ModuleDecl *M, GenericSignature *sig) const;
+  getForwardingSubstitutions(ModuleDecl *M) const;
 
   void dump() const;
 };

include/swift/SIL/TypeSubstCloner.h

@@ -41,8 +41,7 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
 
   void computeSubsMap() {
     if (auto *env = Original.getGenericEnvironment()) {
-      auto sig = Original.getLoweredFunctionType()->getGenericSignature();
-      SubsMap = env->getSubstitutionMap(SwiftMod, sig, ApplySubs);
+      SubsMap = env->getSubstitutionMap(SwiftMod, ApplySubs);
     }
   }
 

lib/AST/GenericEnvironment.cpp

@@ -89,8 +89,7 @@ GenericTypeParamType *GenericEnvironment::getSugaredType(
 }
 
 ArrayRef<Substitution>
-GenericEnvironment::getForwardingSubstitutions(
-    ModuleDecl *M, GenericSignature *sig) const {
+GenericEnvironment::getForwardingSubstitutions(ModuleDecl *M) const {
   auto lookupConformanceFn =
       [&](CanType original, Type replacement, ProtocolType *protoType)
           -> ProtocolConformanceRef {
@@ -105,16 +104,14 @@ GenericEnvironment::getForwardingSubstitutions(
 
 SubstitutionMap GenericEnvironment::
 getSubstitutionMap(ModuleDecl *mod,
-                   GenericSignature *sig,
                    ArrayRef<Substitution> subs) const {
   SubstitutionMap result;
-  getSubstitutionMap(mod, getGenericSignature(), subs, result);
+  getSubstitutionMap(mod, subs, result);
   return result;
 }
 
 void GenericEnvironment::
 getSubstitutionMap(ModuleDecl *mod,
-                   GenericSignature *sig,
                    ArrayRef<Substitution> subs,
                    SubstitutionMap &result) const {
   for (auto depTy : getGenericSignature()->getAllDependentTypes()) {

lib/AST/ProtocolConformance.cpp

@@ -379,10 +379,9 @@ SpecializedProtocolConformance::getTypeWitnessSubstAndDecl(
   auto conformingModule = conformingDC->getParentModule();
 
   auto *genericEnv = GenericConformance->getGenericEnvironment();
-  auto *genericSig = GenericConformance->getGenericSignature();
 
   auto substitutionMap = genericEnv->getSubstitutionMap(
-      conformingModule, genericSig, GenericSubstitutions);
+      conformingModule, GenericSubstitutions);
 
   auto genericWitnessAndDecl
     = GenericConformance->getTypeWitnessSubstAndDecl(assocType, resolver);
@@ -534,10 +533,9 @@ ProtocolConformance::getInheritedConformance(ProtocolDecl *protocol) const {
     auto *conformingDC = spec->getDeclContext();
     auto *conformingModule = conformingDC->getParentModule();
 
-    auto *sig = conformingDC->getGenericSignatureOfContext();
     auto *env = conformingDC->getGenericEnvironmentOfContext();
 
-    auto subMap = env->getSubstitutionMap(conformingModule, sig, subs);
+    auto subMap = env->getSubstitutionMap(conformingModule, subs);
 
     auto r = inherited->subst(conformingModule, getType(), subMap);
     assert(getType()->isEqual(r->getType())

lib/SIL/SILFunction.cpp

@@ -547,9 +547,8 @@ ArrayRef<Substitution> SILFunction::getForwardingSubstitutions() {
   if (!env)
     return {};
 
-  auto sig = getLoweredFunctionType()->getGenericSignature();
   auto *M = getModule().getSwiftModule();
-  ForwardingSubs = env->getForwardingSubstitutions(M, sig);
+  ForwardingSubs = env->getForwardingSubstitutions(M);
 
   return *ForwardingSubs;
 }

lib/SIL/SILVerifier.cpp

@@ -1964,8 +1964,7 @@ public:
 
     // Map interface types to archetypes.
     if (auto *env = constantInfo.GenericEnv) {
-      auto sig = constantInfo.SILFnType->getGenericSignature();
-      auto subs = env->getForwardingSubstitutions(M, sig);
+      auto subs = env->getForwardingSubstitutions(M);
       methodTy = methodTy->substGenericArgs(F.getModule(), M, subs);
     }
     assert(!methodTy->isPolymorphic());

lib/SILGen/SILGenBridging.cpp

@@ -78,11 +78,9 @@ emitBridgeNativeToObjectiveC(SILGenFunction &gen,
     // FIXME: Substitute the type substitutions into the witness, because
     // SpecializedProtocolConformance::getWitness() doesn't do it for us.
     GenericEnvironment *witnessEnv = witness.getSyntheticEnvironment();
-    GenericSignature *witnessSig = witness.getSyntheticSignature();
-    
+
     SubstitutionMap typeSubMap = witnessEnv
       ->getSubstitutionMap(gen.SGM.SwiftModule,
-                           witnessSig,
                            typeSubstitutions);
     for (auto sub : witnessSubstitutions) {
       substitutionsBuf.push_back(sub.subst(gen.SGM.SwiftModule, typeSubMap));

lib/SILGen/SILGenConstructor.cpp

@@ -490,9 +490,8 @@ void SILGenFunction::emitClassConstructorAllocator(ConstructorDecl *ctor) {
   // Call the initializer.
   ArrayRef<Substitution> forwardingSubs;
   if (auto *genericEnv = ctor->getGenericEnvironmentOfContext()) {
-    auto *genericSig = ctor->getGenericSignatureOfContext();
     forwardingSubs = genericEnv->getForwardingSubstitutions(
-        SGM.SwiftModule, genericSig);
+        SGM.SwiftModule);
   }
   std::tie(initVal, initTy, subs)
     = emitSiblingMethodRef(Loc, selfValue, initConstant, forwardingSubs);
@@ -882,9 +881,8 @@ void SILGenFunction::emitMemberInitializers(DeclContext *dc,
         ArrayRef<Substitution> subs;
         auto *genericEnv = dc->getGenericEnvironmentOfContext();
         if (genericEnv) {
-          auto *genericSig = dc->getGenericSignatureOfContext();
           subs = genericEnv->getForwardingSubstitutions(
-              SGM.SwiftModule, genericSig);
+              SGM.SwiftModule);
         }
 
         // Get the type of the initialization result, in terms

lib/SILGen/SILGenFunction.cpp

@@ -815,8 +815,7 @@ void SILGenFunction::emitCurryThunk(ValueDecl *vd,
   ArrayRef<Substitution> subs;
   auto constantInfo = getConstantInfo(to);
   if (auto *env = constantInfo.GenericEnv) {
-    auto sig = constantInfo.SILFnType->getGenericSignature();
-    subs = env->getForwardingSubstitutions(SGM.SwiftModule, sig);
+    subs = env->getForwardingSubstitutions(SGM.SwiftModule);
   }
 
   SILValue toFn = getNextUncurryLevelRef(*this, vd, to, from.isDirectReference,

lib/SILGen/SILGenLValue.cpp

@@ -1582,9 +1582,8 @@ SILGenModule::getNonMemberVarDeclSubstitutions(VarDecl *var) {
   ArrayRef<Substitution> substitutions;
   auto *dc = var->getDeclContext();
   if (auto *genericEnv = dc->getGenericEnvironmentOfContext()) {
-    auto *genericSig = dc->getGenericSignatureOfContext();
     substitutions = genericEnv->getForwardingSubstitutions(
-        SwiftModule, genericSig);
+        SwiftModule);
   }
   return substitutions;
 }