Merge pull request swiftlang#73712 from slavapestov/pack-expansion-closures-part-6

Pack expansion closures, part 6

Author: slavapestov

include/swift/AST/Types.h

@@ -182,7 +182,7 @@ class RecursiveTypeProperties {
     /// Contains a PackType.
     HasPack = 0x10000,
 
-    /// Contains a PackArchetypeType.
+    /// Contains a PackArchetypeType. Also implies HasPrimaryArchetype.
     HasPackArchetype = 0x20000,
 
     Last_Property = HasPackArchetype
@@ -205,7 +205,8 @@ class RecursiveTypeProperties {
   bool hasTypeVariable() const { return Bits & HasTypeVariable; }
 
   /// Does a type with these properties structurally contain a primary
-  /// archetype?
+  /// or pack archetype? These are the archetypes instantiated from a
+  /// primary generic environment.
   bool hasPrimaryArchetype() const { return Bits & HasPrimaryArchetype; }
 
   /// Does a type with these properties structurally contain an
@@ -695,7 +696,9 @@ class alignas(1 << TypeAlignInBits) TypeBase
     return getRecursiveProperties().hasPlaceholder();
   }
 
-  /// Determine whether the type involves a primary archetype.
+  /// Determine whether the type involves a PrimaryArchetypeType *or* a
+  /// PackArchetypeType. These are the archetypes instantiated from a
+  /// primary generic environment.
   bool hasPrimaryArchetype() const {
     return getRecursiveProperties().hasPrimaryArchetype();
   }

include/swift/SIL/SILCloner.h

@@ -448,9 +448,9 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
 
   SILLocation remapLocation(SILLocation Loc) { return Loc; }
   const SILDebugScope *remapScope(const SILDebugScope *DS) { return DS; }
+
   SILType remapType(SILType Ty) {
-    // Substitute local archetypes, if we have any.
-    if (Ty.hasLocalArchetype()) {
+    if (Functor.SubsMap || Ty.hasLocalArchetype()) {
       Ty = Ty.subst(Builder.getModule(), Functor, Functor,
                     CanGenericSignature());
     }
@@ -459,16 +459,14 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
   }
 
   CanType remapASTType(CanType ty) {
-    // Substitute local archetypes, if we have any.
-    if (ty->hasLocalArchetype())
+    if (Functor.SubsMap || ty->hasLocalArchetype())
       ty = ty.subst(Functor, Functor)->getCanonicalType();
 
     return ty;
   }
 
   ProtocolConformanceRef remapConformance(Type Ty, ProtocolConformanceRef C) {
-    // If we have local archetypes to substitute, do so now.
-    if (Ty->hasLocalArchetype())
+    if (Functor.SubsMap || Ty->hasLocalArchetype())
       C = C.subst(Ty, Functor, Functor);
 
     return C;
@@ -485,7 +483,7 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
 
   SubstitutionMap remapSubstitutionMap(SubstitutionMap Subs) {
     // If we have local archetypes to substitute, do so now.
-    if (Subs.hasLocalArchetypes())
+    if (Subs.hasLocalArchetypes() || Functor.SubsMap)
       Subs = Subs.subst(Functor, Functor);
 
     return Subs;

include/swift/SIL/SILModule.h

@@ -477,6 +477,11 @@ class SILModule {
   /// This should only be the case during parsing or deserialization.
   bool hasUnresolvedLocalArchetypeDefinitions();
 
+  /// If we added any instructions that reference unresolved local archetypes
+  /// and then deleted those instructions without resolving those archetypes,
+  /// we must reclaim those unresolved local archetypes.
+  void reclaimUnresolvedLocalArchetypeDefinitions();
+
   /// Get a unique index for a struct or class field in layout order.
   ///
   /// Precondition: \p decl must be a non-resilient struct or class.

include/swift/SIL/TypeLowering.h

@@ -1073,6 +1073,12 @@ class TypeConverter {
   GenericSignatureWithCapturedEnvironments
   getGenericSignatureWithCapturedEnvironments(SILDeclRef constant);
 
+  /// Get the substitution map for calling a constant.
+  SubstitutionMap
+  getSubstitutionMapWithCapturedEnvironments(SILDeclRef constant,
+                                             const CaptureInfo &captureInfo,
+                                             SubstitutionMap subs);
+
   /// Get the generic environment for a constant.
   GenericEnvironment *getConstantGenericEnvironment(SILDeclRef constant);
 

lib/SIL/IR/SILModule.cpp

@@ -687,13 +687,16 @@ SILValue SILModule::getRootLocalArchetypeDef(CanLocalArchetypeType archetype,
   return def;
 }
 
-bool SILModule::hasUnresolvedLocalArchetypeDefinitions() {
-  // Garbage collect dead placeholders first.
+void SILModule::reclaimUnresolvedLocalArchetypeDefinitions() {
   llvm::DenseMap<LocalArchetypeKey, SILValue> newLocalArchetypeDefs;
 
   for (auto pair : RootLocalArchetypeDefs) {
     if (auto *placeholder = dyn_cast<PlaceholderValue>(pair.second)) {
+      // If a placeholder has no uses, the instruction that introduced it
+      // was deleted before the local archetype was resolved. Reclaim the
+      // placeholder so that we don't complain.
       if (placeholder->use_empty()) {
+        assert(numUnresolvedLocalArchetypes > 0);
         --numUnresolvedLocalArchetypes;
         ::delete placeholder;
         continue;
@@ -704,7 +707,9 @@ bool SILModule::hasUnresolvedLocalArchetypeDefinitions() {
   }
 
   std::swap(newLocalArchetypeDefs, RootLocalArchetypeDefs);
+}
 
+bool SILModule::hasUnresolvedLocalArchetypeDefinitions() {
   return numUnresolvedLocalArchetypes != 0;
 }
 

lib/SIL/IR/TypeLowering.cpp

@@ -4104,12 +4104,27 @@ TypeConverter::getGenericSignatureWithCapturedEnvironments(SILDeclRef c) {
         vd->getDeclContext()->getGenericSignatureOfContext());
   case SILDeclRef::Kind::EntryPoint:
   case SILDeclRef::Kind::AsyncEntryPoint:
-    llvm_unreachable("Doesn't have generic signature");
+    return GenericSignatureWithCapturedEnvironments();
   }
 
   llvm_unreachable("Unhandled SILDeclRefKind in switch.");
 }
 
+SubstitutionMap
+TypeConverter::getSubstitutionMapWithCapturedEnvironments(
+    SILDeclRef constant, const CaptureInfo &captureInfo,
+    SubstitutionMap subs) {
+  auto sig = getGenericSignatureWithCapturedEnvironments(constant);
+  if (!sig.genericSig) {
+    assert(!sig.baseGenericSig);
+    assert(sig.capturedEnvs.empty());
+    return SubstitutionMap();
+  }
+
+  return buildSubstitutionMapWithCapturedEnvironments(
+      subs, sig.genericSig, sig.capturedEnvs);
+}
+
 GenericEnvironment *
 TypeConverter::getConstantGenericEnvironment(SILDeclRef c) {
   return getGenericSignatureWithCapturedEnvironments(c)

lib/SILGen/CMakeLists.txt

@@ -28,6 +28,7 @@ add_swift_host_library(swiftSILGen STATIC
   SILGenFunction.cpp
   SILGenGlobalVariable.cpp
   SILGenLazyConformance.cpp
+  SILGenLocalArchetype.cpp
   SILGenLValue.cpp
   SILGenPack.cpp
   SILGenPattern.cpp

lib/SILGen/SILGen.cpp

@@ -1260,6 +1260,9 @@ void SILGenModule::postEmitFunction(SILDeclRef constant,
                                     SILFunction *F) {
   emitLazyConformancesForFunction(F);
 
+  auto sig = Types.getGenericSignatureWithCapturedEnvironments(constant);
+  recontextualizeCapturedLocalArchetypes(F, sig);
+
   assert(!F->isExternalDeclaration() && "did not emit any function body?!");
   LLVM_DEBUG(llvm::dbgs() << "lowered sil:\n";
              F->print(llvm::dbgs()));

lib/SILGen/SILGen.h

@@ -625,6 +625,11 @@ class LLVM_LIBRARY_VISIBILITY SILGenModule : public ASTVisitor<SILGenModule> {
   /// Emit a property descriptor for the given storage decl if it needs one.
   void tryEmitPropertyDescriptor(AbstractStorageDecl *decl);
 
+  /// Replace local archetypes captured from outer AST contexts with primary
+  /// archetypes.
+  void recontextualizeCapturedLocalArchetypes(
+      SILFunction *F, GenericSignatureWithCapturedEnvironments sig);
+
 private:
   /// The most recent declaration we considered for emission.
   SILDeclRef lastEmittedFunction;

lib/SILGen/SILGenApply.cpp

@@ -1225,9 +1225,8 @@ class SILGenApply : public Lowering::ExprVisitor<SILGenApply> {
     auto captureInfo = SGF.SGM.Types.getLoweredLocalCaptures(constant);
     SGF.SGM.Types.setCaptureTypeExpansionContext(constant, SGF.SGM.M);
 
-    if (afd->getDeclContext()->isLocalContext() &&
-        !captureInfo.hasGenericParamCaptures())
-      subs = SubstitutionMap();
+    subs = SGF.SGM.Types.getSubstitutionMapWithCapturedEnvironments(
+        constant, captureInfo, subs);
 
     // Check whether we have to dispatch to the original implementation of a
     // dynamically_replaceable inside of a dynamic_replacement(for:) function.
@@ -1304,17 +1303,14 @@ class SILGenApply : public Lowering::ExprVisitor<SILGenApply> {
 
     // A directly-called closure can be emitted as a direct call instead of
     // really producing a closure object.
-
-    auto captureInfo = SGF.SGM.M.Types.getLoweredLocalCaptures(constant);
-
     SubstitutionMap subs;
-    if (captureInfo.hasGenericParamCaptures())
-      subs = SGF.getForwardingSubstitutionMap();
+    std::tie(std::ignore, std::ignore, subs)
+        = SGF.SGM.Types.getForwardingSubstitutionsForLowering(constant);
 
     setCallee(Callee::forDirect(SGF, constant, subs, e));
 
     // If the closure requires captures, emit them.
-    if (!captureInfo.getCaptures().empty()) {
+    if (SGF.SGM.Types.hasLoweredLocalCaptures(constant)) {
       SmallVector<ManagedValue, 4> captures;
       SGF.emitCaptures(e, constant, CaptureEmission::ImmediateApplication,
                        captures);
@@ -6712,14 +6708,9 @@ static Callee getBaseAccessorFunctionRef(SILGenFunction &SGF,
         subs, loc, true);
   }
 
-  // The accessor might be a local function that does not capture any
-  // generic parameters, in which case we don't want to pass in any
-  // substitutions.
   auto captureInfo = SGF.SGM.Types.getLoweredLocalCaptures(constant);
-  if (decl->getDeclContext()->isLocalContext() &&
-      !captureInfo.hasGenericParamCaptures()) {
-    subs = SubstitutionMap();
-  }
+  subs = SGF.SGM.Types.getSubstitutionMapWithCapturedEnvironments(
+      constant, captureInfo, subs);
 
   // If this is a method in a protocol, generate it as a protocol call.
   if (isa<ProtocolDecl>(decl->getDeclContext())) {

lib/SILGen/SILGenExpr.cpp

@@ -3028,14 +3028,11 @@ RValueEmitter::emitClosureReference(AbstractClosureExpr *e,
   // Emit the closure body.
   SGF.SGM.emitClosure(e, contextInfo);
 
-  SubstitutionMap subs;
-  if (e->getCaptureInfo().hasGenericParamCaptures())
-    subs = SGF.getForwardingSubstitutionMap();
-
   // Generate the closure value (if any) for the closure expr's function
   // reference.
   SILLocation loc = e;
-  return SGF.emitClosureValue(loc, SILDeclRef(e), contextInfo, subs);
+  return SGF.emitClosureValue(loc, SILDeclRef(e), contextInfo,
+                              SubstitutionMap());
 }
 
 RValue RValueEmitter::

lib/SILGen/SILGenFunction.cpp

@@ -977,28 +977,26 @@ SILGenFunction::emitClosureValue(SILLocation loc, SILDeclRef constant,
   // Apply substitutions.
   auto pft = constantInfo.SILFnType;
 
-  auto closure = *constant.getAnyFunctionRef();
-  auto *dc = closure.getAsDeclContext()->getParent();
-  if (dc->isLocalContext() && !loweredCaptureInfo.hasGenericParamCaptures()) {
-    // If the lowered function type is not polymorphic but we were given
-    // substitutions, we have a closure in a generic context which does not
-    // capture generic parameters. Just drop the substitutions.
-    subs = { };
-  } else if (closure.getAbstractClosureExpr()) {
+  if (constant.getAbstractClosureExpr()) {
     // If we have a closure expression in generic context, Sema won't give
     // us substitutions, so we just use the forwarding substitutions from
     // context.
-    subs = getForwardingSubstitutionMap();
+    std::tie(std::ignore, std::ignore, subs)
+        = SGM.Types.getForwardingSubstitutionsForLowering(constant);
+  } else {
+    subs = SGM.Types.getSubstitutionMapWithCapturedEnvironments(
+        constant, loweredCaptureInfo, subs);
   }
 
-  bool wasSpecialized = false;
-  if (!subs.empty()) {
+  if (subs) {
     auto specialized =
         pft->substGenericArgs(F.getModule(), subs, getTypeExpansionContext());
     functionTy = SILType::getPrimitiveObjectType(specialized);
-    wasSpecialized = true;
   }
 
+  auto closure = *constant.getAnyFunctionRef();
+  auto *dc = closure.getAsDeclContext()->getParent();
+
   // If we're in top-level code, we don't need to physically capture script
   // globals, but we still need to mark them as escaping so that DI can flag
   // uninitialized uses.
@@ -1011,7 +1009,7 @@ SILGenFunction::emitClosureValue(SILLocation loc, SILDeclRef constant,
     typeContext.ExpectedLoweredType->hasErasedIsolation();
 
   ManagedValue result;
-  if (loweredCaptureInfo.getCaptures().empty() && !wasSpecialized &&
+  if (loweredCaptureInfo.getCaptures().empty() && !subs &&
       !hasErasedIsolation) {
     result = ManagedValue::forObjectRValueWithoutOwnership(functionRef);
   } else {

lib/SILGen/SILGenLazyConformance.cpp

@@ -9,6 +9,11 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
+//
+//  This file forces emission of lazily-generated ClangImporter-synthesized
+//  conformances.
+//
+//===----------------------------------------------------------------------===//
 
 #include "SILGen.h"
 #include "swift/AST/Decl.h"