Serialization support for SIL substituted function types

Author: jckarter

lib/AST/Type.cpp

@@ -4843,3 +4843,14 @@ CanType swift::substOpaqueTypesWithUnderlyingTypes(CanType ty,
         SubstFlags::SubstituteOpaqueArchetypes | SubstFlags::AllowLoweredTypes;
   return ty.subst(replacer, replacer, flags)->getCanonicalType();
 }
+
+CanSILFunctionType
+SILFunctionType::withSubstitutions(SubstitutionMap subs) const {
+  return SILFunctionType::get(getSubstGenericSignature(),
+                          getExtInfo(), getCoroutineKind(),
+                          getCalleeConvention(),
+                          getParameters(), getYields(), getResults(),
+                          getOptionalErrorResult(),
+                          subs, isGenericSignatureImplied(),
+                          const_cast<SILFunctionType*>(this)->getASTContext());
+}

lib/SIL/SILFunctionType.cpp

@@ -3334,17 +3334,6 @@ StringRef SILFunctionType::ABICompatibilityCheckResult::getMessage() const {
   llvm_unreachable("Covered switch isn't completely covered?!");
 }
 
-CanSILFunctionType
-SILFunctionType::withSubstitutions(SubstitutionMap subs) const {
-  return SILFunctionType::get(getSubstGenericSignature(),
-                          getExtInfo(), getCoroutineKind(),
-                          getCalleeConvention(),
-                          getParameters(), getYields(), getResults(),
-                          getOptionalErrorResult(),
-                          subs, isGenericSignatureImplied(),
-                          const_cast<SILFunctionType*>(this)->getASTContext());
-}
-
 static DeclContext *getDeclContextForExpansion(const SILFunction &f) {
   auto *dc = f.getDeclContext();
   if (!dc)

lib/Sema/TypeCheckType.cpp

@@ -2744,7 +2744,8 @@ Type TypeResolver::resolveSILFunctionType(FunctionTypeRepr *repr,
       subsMap.insert({params[i], resolved->getCanonicalType()});
     }
     subs = SubstitutionMap::get(sig, QueryTypeSubstitutionMap{subsMap},
-                                TypeChecker::LookUpConformance(DC));
+                                TypeChecker::LookUpConformance(DC))
+      .getCanonical();
   }
 
   if (hasError) {

lib/Serialization/Deserialization.cpp

@@ -5029,7 +5029,9 @@ class swift::TypeDeserializer {
     unsigned numParams;
     unsigned numYields;
     unsigned numResults;
+    bool isGenericSignatureImplied;
     GenericSignatureID rawGenericSig;
+    SubstitutionMapID rawSubs;
     ArrayRef<uint64_t> variableData;
     clang::FunctionType *clangFunctionType = nullptr;
 
@@ -5046,7 +5048,9 @@ class swift::TypeDeserializer {
                                              numParams,
                                              numYields,
                                              numResults,
+                                             isGenericSignatureImplied,
                                              rawGenericSig,
+                                             rawSubs,
                                              variableData);
 
     // Process the ExtInfo.
@@ -5166,11 +5170,13 @@ class swift::TypeDeserializer {
     }
 
     GenericSignature genericSig = MF.getGenericSignature(rawGenericSig);
+    SubstitutionMap subs = MF.getSubstitutionMap(rawSubs).getCanonical();
+    
     return SILFunctionType::get(genericSig, extInfo, coroutineKind.getValue(),
                                 calleeConvention.getValue(),
                                 allParams, allYields, allResults,
                                 errorResult,
-                                SubstitutionMap(), false,
+                                subs, isGenericSignatureImplied,
                                 ctx, witnessMethodConformance);
   }
 

lib/Serialization/ModuleFormat.h

@@ -55,7 +55,7 @@ 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 = 528; // @derivative attribute
+const uint16_t SWIFTMODULE_VERSION_MINOR = 529; // SILFunctionType substitutions
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///
@@ -990,11 +990,14 @@ namespace decls_block {
     BCVBR<6>,              // number of parameters
     BCVBR<5>,              // number of yields
     BCVBR<5>,              // number of results
+    BCFixed<1>,            // generic signature implied
     GenericSignatureIDField, // generic signature
+    SubstitutionMapIDField, // substitutions
     BCArray<TypeIDField>   // parameter types/conventions, alternating
                            // followed by result types/conventions, alternating
                            // followed by error result type/convention
     // Optionally a protocol conformance (for witness_methods)
+    // Optionally a substitution map (for substituted function types)
   >;
 
   using SILBlockStorageTypeLayout = BCRecordLayout<

lib/Serialization/Serialization.cpp

@@ -4091,7 +4091,10 @@ class Serializer::TypeSerializer : public TypeVisitor<TypeSerializer> {
         stableRepresentation, fnTy->isPseudogeneric(), fnTy->isNoEscape(),
         stableDiffKind, fnTy->hasErrorResult(), fnTy->getParameters().size(),
         fnTy->getNumYields(), fnTy->getNumResults(),
-        S.addGenericSignatureRef(sig), variableData);
+        fnTy->isGenericSignatureImplied(),
+        S.addGenericSignatureRef(sig),
+        S.addSubstitutionMapRef(fnTy->getSubstitutions()),
+        variableData);
 
     if (auto conformance = fnTy->getWitnessMethodConformanceOrInvalid())
       S.writeConformance(conformance, S.DeclTypeAbbrCodes);

test/SIL/Serialization/basic.sil

@@ -38,6 +38,12 @@ struct Int32 {
   var x: Builtin.Int32
 }
 
+// CHECK-LABEL: sil [serialized] [ossa] @test_subst_function_type : $@convention(thin) (@guaranteed @callee_guaranteed <τ_0_0, τ_0_1> in (@in τ_0_0, @in τ_0_1) -> () for <Builtin.Int32, Builtin.Int64>) -> ()
+sil [serialized] [ossa] @test_subst_function_type : $@convention(thin) (@guaranteed @callee_guaranteed <A, B> in (@in A, @in B) -> () for <Builtin.Int32, Builtin.Int64>) -> () {
+entry(%0 : @guaranteed $@callee_guaranteed <C, D> in (@in C, @in D) -> () for <Builtin.Int32, Builtin.Int64>):
+  return undef : $()
+}
+
 sil [ossa] @test_destructure_struct_tuple : $@convention(thin) (@owned (Builtin.NativeObject, Builtin.Int32), @owned TestArray2) -> @owned (Builtin.NativeObject, Builtin.Int32, TestArrayStorage, Int32, TestArrayStorage) {
 bb0(%0 : @owned $(Builtin.NativeObject, Builtin.Int32), %1 : @owned $TestArray2):
   (%2, %3) = destructure_tuple %0 : $(Builtin.NativeObject, Builtin.Int32)
@@ -46,6 +52,12 @@ bb0(%0 : @owned $(Builtin.NativeObject, Builtin.Int32), %1 : @owned $TestArray2)
   return %7 : $(Builtin.NativeObject, Builtin.Int32, TestArrayStorage, Int32, TestArrayStorage)
 }
 
+// CHECK-LABEL: sil [serialized] [ossa] @test_subst_function_type_generic_context : $@convention(thin) <X, Y> (@guaranteed @callee_guaranteed <τ_0_0, τ_0_1> in (@in τ_0_0, @in τ_0_1) -> () for <X, Y>) -> ()
+sil [serialized] [ossa] @test_subst_function_type_generic_context : $@convention(thin) <X, Y> (@guaranteed @callee_guaranteed <A, B> in (@in A, @in B) -> () for <X, Y>) -> () {
+entry(%0 : @guaranteed $@callee_guaranteed <C, D> in (@in C, @in D) -> () for <X, Y>):
+  return undef : $()
+}
+
 struct EmptyStruct {}
 
 sil @test_empty_destructure : $@convention(thin) () -> () {