Merge pull request swiftlang#62466 from slavapestov/simplify-subst-function-type-pattern-visitor

Simplify SubstFunctionTypePatternVisitor

Author: slavapestov

lib/SIL/IR/AbstractionPattern.cpp

@@ -1745,119 +1745,31 @@ class SubstFunctionTypePatternVisitor
     }
 
     auto decl = orig->getAnyNominal();
-    
-    // Any type parameters we use as arguments to the nominal type must still
-    // satisfy the requirements on the nominal type. So we pull all of the
-    // generic requirements from the nominal type declaration into the
-    // substituted signature, then same-type-constrain those variables to the
-    // types we get by recursively visiting the bound generic arguments.
+
     auto moduleDecl = decl->getParentModule();
-    auto origSubMap = orig->getContextSubstitutionMap(moduleDecl,
-                                                decl,
-                                                decl->getGenericEnvironment());
-    auto substSubMap = subst->getContextSubstitutionMap(moduleDecl, decl,
-                                                decl->getGenericEnvironment());
-    
-    auto nomGenericSig = decl->getGenericSignature().getCanonicalSignature();
-    
-    llvm::DenseMap<GenericTypeParamType*, GenericTypeParamType*>
-      substGPMapping;
-    
-    // Create parallel generic params for the nominal type's generic params.
-    for (unsigned i = 0; i < nomGenericSig.getGenericParams().size(); ++i) {
-      auto nomTyParam = nomGenericSig.getGenericParams()[i];
-      // If the nominal type same-type constrains away this generic parameter,
-      // we don't need to visit it.
-      if (nomGenericSig->isConcreteType(nomTyParam))
-        continue;
-      
-      unsigned substGPIndex = substGenericParams.size();
-      auto substGP = GenericTypeParamType::get(false, 0,
-                                               substGPIndex, TC.Context);
-      substGenericParams.push_back(substGP);
-      substReplacementTypes.push_back(Type());
-      substGPMapping.insert({nomGenericSig.getGenericParams()[i], substGP});
-    }
+    auto origSubMap = orig->getContextSubstitutionMap(moduleDecl, decl);
+    auto substSubMap = subst->getContextSubstitutionMap(moduleDecl, decl);
 
-    // Create parallel requirements too, mapping from the generic signature's
-    // params to our parallel params.
-    auto substGPMap = SubstitutionMap::get(nomGenericSig,
-      [&](SubstitutableType *dt) -> Type {
-        auto mapping = substGPMapping.find(cast<GenericTypeParamType>(dt));
-        assert(mapping != substGPMapping.end());
-        return mapping->second;
-      }, [&](CanType dependentType,
-             Type conformingReplacementType,
-             ProtocolDecl *conformedProtocol) -> ProtocolConformanceRef {
-        // We should always be substituting type parameter for type parameter
-        return ProtocolConformanceRef(conformedProtocol);
-      });
-    
-    for (auto reqt : nomGenericSig.getRequirements()) {
-      auto firstTy = reqt.getFirstType().subst(substGPMap);
-      switch (auto kind = reqt.getKind()) {
-      case RequirementKind::SameShape:
-        llvm_unreachable("Same-shape requirement not supported here");
-
-      case RequirementKind::SameType:
-        // Skip same-type constraints that define away primary generic params,
-        // since we didn't duplicate those params.
-        if (reqt.getFirstType()->getAs<GenericTypeParamType>()
-            && nomGenericSig->isConcreteType(reqt.getFirstType()))
-          continue;
-          
-        LLVM_FALLTHROUGH;
-      case RequirementKind::Conformance:
-      case RequirementKind::Superclass: {
-        auto secondTy = reqt.getSecondType().subst(substGPMap);
-        substRequirements.push_back(Requirement(kind, firstTy, secondTy));
-        break;
-      }
-      case RequirementKind::Layout:
-        substRequirements.push_back(Requirement(kind, firstTy,
-                                                reqt.getLayoutConstraint()));
-        break;
-      }
-    }
+    auto nomGenericSig = decl->getGenericSignature();
 
-    // Now recur into the type arguments, and same-type-constrain the
-    // substituted type arguments to the parallel generic parameter, giving us
-    // the intersection of constraints on the type binding and the nominal type's
-    // requirements.
-    llvm::DenseMap<GenericTypeParamType*, Type>
-      newGPMapping;
-
+    TypeSubstitutionMap replacementTypes;
     for (auto gp : nomGenericSig.getGenericParams()) {
-      if (nomGenericSig->isConcreteType(gp))
-        continue;
-      
       auto origParamTy = Type(gp).subst(origSubMap)
         ->getCanonicalType();
       auto substParamTy = Type(gp).subst(substSubMap)
         ->getCanonicalType();
-      
-      auto newParamTy = visit(substParamTy,
-                              AbstractionPattern(origSig, origParamTy));
-      newGPMapping.insert({gp, newParamTy});
-      auto substGPTy = Type(gp).subst(substGPMap)->castTo<GenericTypeParamType>();
-      substRequirements.push_back(Requirement(RequirementKind::SameType,
-                                              newParamTy,
-                                              substGPTy));
-      assert(!substReplacementTypes[substGPTy->getIndex()]);
-      substReplacementTypes[substGPTy->getIndex()] = substParamTy;
+
+      replacementTypes[gp->getCanonicalType()->castTo<SubstitutableType>()]
+          = visit(substParamTy, AbstractionPattern(origSig, origParamTy));
     }
-    
+
     auto newSubMap = SubstitutionMap::get(nomGenericSig,
-      [&](SubstitutableType *dt) -> Type {
-        auto mapping = newGPMapping.find(cast<GenericTypeParamType>(dt));
-        assert(mapping != newGPMapping.end());
-        return mapping->second;
-      }, [&](CanType dependentType,
-             Type conformingReplacementType,
-             ProtocolDecl *conformedProtocol) -> ProtocolConformanceRef {
-        // We should always be substituting type parameter for type parameter
-        return ProtocolConformanceRef(conformedProtocol);
-      });
+      QueryTypeSubstitutionMap{replacementTypes},
+      LookUpConformanceInModule(moduleDecl));
+    
+    for (auto reqt : nomGenericSig.getRequirements()) {
+      substRequirements.push_back(reqt.subst(newSubMap));
+    }
 
     return decl->getDeclaredInterfaceType().subst(newSubMap)->getCanonicalType();
   }

lib/Serialization/ModuleFormat.h

@@ -58,7 +58,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 725; // macro declarations
+const uint16_t SWIFTMODULE_VERSION_MINOR = 726; // SIL function lowering change
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///

test/SILGen/coroutine_subst_function_types.swift

@@ -63,7 +63,7 @@ class ConcreteWithInt: Generic<Int> {
     set {}
   }
 
-  // CHECK-LABEL: sil private [thunk] [ossa] @$s3mod15ConcreteWithIntC12complexTupleSiSg_SDySSSiGtvMAA7GenericCADxSg_SDySSxGtvMTV : $@yield_once @convention(method) @substituted <τ_0_0, τ_0_1, τ_0_2, τ_0_3, τ_0_4 where τ_0_0 == τ_0_1, τ_0_2 == String, τ_0_3 == τ_0_4> (@guaranteed ConcreteWithInt) -> @yields @inout (Optional<τ_0_0>, Dictionary<String, τ_0_3>) for <Int, Int, String, Int, Int>
+  // CHECK-LABEL: sil private [thunk] [ossa] @$s3mod15ConcreteWithIntC12complexTupleSiSg_SDySSSiGtvMAA7GenericCADxSg_SDySSxGtvMTV : $@yield_once @convention(method) @substituted <τ_0_0, τ_0_1> (@guaranteed ConcreteWithInt) -> @yields @inout (Optional<τ_0_0>, Dictionary<String, τ_0_1>) for <Int, Int>
   override var complexTuple: (Int?, [String: Int]) {
     get { super.complexTuple }
     set {}
@@ -110,7 +110,7 @@ extension ConcreteWithInt : ProtoWithAssoc {
 
   //   var complexTuple
   // CHECK-LABEL: sil shared [ossa] @$s3mod15ConcreteWithIntC12complexTupleSiSg_SDySSSiGtvr : $@yield_once @convention(method) (@guaranteed ConcreteWithInt) -> (@yields Optional<Int>, @yields @guaranteed Dictionary<String, Int>)
-  // CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s3mod15ConcreteWithIntCAA05ProtoC5AssocA2aDP12complexTuple0F0QzSg_SDySSAHGtvMTW : $@yield_once @convention(witness_method: ProtoWithAssoc) @substituted <τ_0_0, τ_0_1, τ_0_2, τ_0_3, τ_0_4, τ_0_5 where τ_0_1 == τ_0_2, τ_0_3 == String, τ_0_4 == τ_0_5> (@inout τ_0_0) -> @yields @inout (Optional<τ_0_1>, Dictionary<String, τ_0_4>) for <ConcreteWithInt, Int, Int, String, Int, Int>
+  // CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s3mod15ConcreteWithIntCAA05ProtoC5AssocA2aDP12complexTuple0F0QzSg_SDySSAHGtvMTW : $@yield_once @convention(witness_method: ProtoWithAssoc) @substituted <τ_0_0, τ_0_1, τ_0_2> (@inout τ_0_0) -> @yields @inout (Optional<τ_0_1>, Dictionary<String, τ_0_2>) for <ConcreteWithInt, Int, Int>
 }
 
 // CHECK-LABEL: sil_vtable ConcreteWithInt {