Merge remote-tracking branch 'origin/main' into rebranch

docs/Lexicon.md

@@ -49,7 +49,7 @@ thunk helpers" sometimes seen in Swift backtraces come from.)
 
 Broadly, an "access path" is a list of "accesses" which must be chained together
 to compute some output from an input. For instance, the generics system has a
-type called a `ConformanceAccessPath` which explains how to, for example,
+type called a `ConformancePath` which explains how to, for example,
 walk from `T: Collection` to `T: Sequence` to `T.Iterator: IteratorProtocol`.
 There are several different kinds of "access path" in different parts of the compiler,
 but they all follow this basic theme.

include/swift/AST/ASTMangler.h

@@ -25,7 +25,7 @@ class NamedDecl;
 namespace swift {
 
 class AbstractClosureExpr;
-class ConformanceAccessPath;
+class ConformancePath;
 class RootProtocolConformance;
 
 namespace Mangle {
@@ -560,7 +560,7 @@ protected:
   void appendConcreteProtocolConformance(
                                         const ProtocolConformance *conformance,
                                         GenericSignature sig);
-  void appendDependentProtocolConformance(const ConformanceAccessPath &path,
+  void appendDependentProtocolConformance(const ConformancePath &path,
                                           GenericSignature sig);
   void appendOpParamForLayoutConstraint(LayoutConstraint Layout);
   

include/swift/AST/GenericSignature.h

@@ -70,7 +70,7 @@ namespace rewriting {
 /// \c Sequence conformance of \c C (because \c Collection inherits
 /// \c Sequence). Finally, it extracts the conformance of the associated type
 /// \c Iterator to \c IteratorProtocol from the \c Sequence protocol.
-class ConformanceAccessPath {
+class ConformancePath {
 public:
   /// An entry in the conformance access path, which is described by the
   /// dependent type on which the conformance is stated as the protocol to
@@ -80,7 +80,7 @@ public:
 private:
   ArrayRef<Entry> path;
 
-  ConformanceAccessPath(ArrayRef<Entry> path) : path(path) {}
+  ConformancePath(ArrayRef<Entry> path) : path(path) {}
 
   friend class GenericSignatureImpl;
   friend class rewriting::RequirementMachine;
@@ -398,20 +398,20 @@ public:
   /// signature.
   bool isValidTypeParameter(Type type) const;
 
-  /// Retrieve the conformance access path used to extract the conformance of
+  /// Retrieve the conformance path used to extract the conformance of
   /// interface \c type to the given \c protocol.
   ///
-  /// \param type The interface type whose conformance access path is to be
+  /// \param type The type parameter whose conformance path is to be
   /// queried.
   /// \param protocol A protocol to which \c type conforms.
   ///
-  /// \returns the conformance access path that starts at a requirement of
+  /// \returns the conformance path that starts at a requirement of
   /// this generic signature and ends at the conformance that makes \c type
   /// conform to \c protocol.
   ///
-  /// \seealso ConformanceAccessPath
+  /// \seealso ConformancePath
-  ConformanceAccessPath getConformanceAccessPath(Type type,
+  ConformancePath getConformancePath(Type type,
-                                                 ProtocolDecl *protocol) const;
+                                     ProtocolDecl *protocol) const;
 
   /// Lookup a nested type with the given name within this type parameter.
   TypeDecl *lookupNestedType(Type type, Identifier name) const;

include/swift/Basic/Statistics.def

@@ -230,16 +230,8 @@ FRONTEND_STATISTIC(Sema, NumRequirementMachineCompletionSteps)
 /// Number of new rules added by concrete term unification.
 FRONTEND_STATISTIC(Sema, NumRequirementMachineUnifiedConcreteTerms)
 
-/// Number of generic signature builders constructed. Rough proxy for
+/// Number of conformance paths we had to compute.
-/// amount of work the GSB does analyzing type signatures.
+FRONTEND_STATISTIC(Sema, NumConformancePathsRecorded)
-FRONTEND_STATISTIC(Sema, NumGenericSignatureBuilders)
-
-/// Number of steps in the GSB's redundant requirements algorithm, which is in
-/// the worst-case exponential.
-FRONTEND_STATISTIC(Sema, NumRedundantRequirementSteps)
-
-/// Number of conformance access paths we had to compute.
-FRONTEND_STATISTIC(Sema, NumConformanceAccessPathsRecorded)
 
 /// Number of lazy requirement signatures registered.
 FRONTEND_STATISTIC(Sema, NumLazyRequirementSignatures)

lib/AST/ASTMangler.cpp

@@ -3357,9 +3357,9 @@ void ASTMangler::appendProtocolConformanceRef(
 }
 
 /// Retrieve the index of the conformance requirement indicated by the
-/// conformance access path entry within the given set of requirements.
+/// conformance path entry within the given set of requirements.
 static unsigned conformanceRequirementIndex(
-                                      const ConformanceAccessPath::Entry &entry,
+                                      const ConformancePath::Entry &entry,
                                       ArrayRef<Requirement> requirements) {
   unsigned result = 0;
   for (const auto &req : requirements) {
@@ -3377,7 +3377,7 @@ static unsigned conformanceRequirementIndex(
 }
 
 void ASTMangler::appendDependentProtocolConformance(
-                                            const ConformanceAccessPath &path,
+                                            const ConformancePath &path,
                                             GenericSignature sig) {
   ProtocolDecl *currentProtocol = nullptr;
   for (const auto &entry : path) {
@@ -3441,19 +3441,19 @@ void ASTMangler::appendAnyProtocolConformance(
 
   if (conformingType->isTypeParameter()) {
     assert(genericSig && "Need a generic signature to resolve conformance");
-    auto path = genericSig->getConformanceAccessPath(conformingType,
+    auto path = genericSig->getConformancePath(conformingType,
-                                                     conformance.getAbstract());
+                                               conformance.getAbstract());
     appendDependentProtocolConformance(path, genericSig);
   } else if (auto opaqueType = conformingType->getAs<OpaqueTypeArchetypeType>()) {
     GenericSignature opaqueSignature =
         opaqueType->getDecl()->getOpaqueInterfaceGenericSignature();
-    ConformanceAccessPath conformanceAccessPath =
+    ConformancePath conformancePath =
-        opaqueSignature->getConformanceAccessPath(
+        opaqueSignature->getConformancePath(
           opaqueType->getInterfaceType(),
           conformance.getAbstract());
 
-    // Append the conformance access path with the signature of the opaque type.
+    // Append the conformance path with the signature of the opaque type.
-    appendDependentProtocolConformance(conformanceAccessPath, opaqueSignature);
+    appendDependentProtocolConformance(conformancePath, opaqueSignature);
     appendType(conformingType, genericSig);
     appendOperator("HO");
   } else {

lib/AST/GenericSignature.cpp

@@ -29,7 +29,7 @@
 
 using namespace swift;
 
-void ConformanceAccessPath::print(raw_ostream &out) const {
+void ConformancePath::print(raw_ostream &out) const {
   llvm::interleave(
       begin(), end(),
       [&](const Entry &entry) {
@@ -39,7 +39,7 @@ void ConformanceAccessPath::print(raw_ostream &out) const {
       [&] { out << " -> "; });
 }
 
-void ConformanceAccessPath::dump() const {
+void ConformancePath::dump() const {
   print(llvm::errs());
   llvm::errs() << "\n";
 }
@@ -475,10 +475,10 @@ CanGenericSignature::getGenericParams() const {
   return {base, params.size()};
 }
 
-ConformanceAccessPath
+ConformancePath
-GenericSignatureImpl::getConformanceAccessPath(Type type,
+GenericSignatureImpl::getConformancePath(Type type,
-                                               ProtocolDecl *protocol) const {
+                                         ProtocolDecl *protocol) const {
-  return getRequirementMachine()->getConformanceAccessPath(type, protocol);
+  return getRequirementMachine()->getConformancePath(type, protocol);
 }
 
 TypeDecl *

lib/AST/RequirementMachine/GenericSignatureQueries.cpp

@@ -28,7 +28,7 @@
 // arbitrary type, not just a type parameter, and recursively transfozms the
 // type parameters it contains, if any.
 //
-// Also, getConformanceAccessPath() is another one-off operation.
+// Also, getConformancePath() is another one-off operation.
 //
 //===----------------------------------------------------------------------===//
 
@@ -469,7 +469,7 @@ bool RequirementMachine::isValidTypeParameter(Type type) const {
   return (prefix == term);
 }
 
-/// Retrieve the conformance access path used to extract the conformance of
+/// Retrieve the conformance path used to extract the conformance of
 /// interface \c type to the given \c protocol.
 ///
 /// \param type The interface type whose conformance access path is to be
@@ -480,10 +480,10 @@ bool RequirementMachine::isValidTypeParameter(Type type) const {
 /// this generic signature and ends at the conformance that makes \c type
 /// conform to \c protocol.
 ///
-/// \seealso ConformanceAccessPath
+/// \seealso ConformancePath
-ConformanceAccessPath
+ConformancePath
-RequirementMachine::getConformanceAccessPath(Type type,
+RequirementMachine::getConformancePath(Type type,
-                                             ProtocolDecl *protocol) {
+                                       ProtocolDecl *protocol) {
   assert(type->isTypeParameter());
 
   auto mutTerm = Context.getMutableTermForType(type->getCanonicalType(),
@@ -505,9 +505,9 @@ RequirementMachine::getConformanceAccessPath(Type type,
   auto term = Term::get(mutTerm, Context);
 
   // Check if we've already cached the result before doing anything else.
-  auto found = ConformanceAccessPaths.find(
+  auto found = ConformancePaths.find(
       std::make_pair(term, protocol));
-  if (found != ConformanceAccessPaths.end()) {
+  if (found != ConformancePaths.end()) {
     return found->second;
   }
 
@@ -516,25 +516,25 @@ RequirementMachine::getConformanceAccessPath(Type type,
   FrontendStatsTracer tracer(Stats, "get-conformance-access-path");
 
   auto recordPath = [&](Term term, ProtocolDecl *proto,
-                        ConformanceAccessPath path) {
+                        ConformancePath path) {
     // Add the path to the buffer.
-    CurrentConformanceAccessPaths.emplace_back(term, path);
+    CurrentConformancePaths.emplace_back(term, path);
 
     // Add the path to the map.
     auto key = std::make_pair(term, proto);
-    auto inserted = ConformanceAccessPaths.insert(
+    auto inserted = ConformancePaths.insert(
         std::make_pair(key, path));
     assert(inserted.second);
     (void) inserted;
 
     if (Stats)
-      ++Stats->getFrontendCounters().NumConformanceAccessPathsRecorded;
+      ++Stats->getFrontendCounters().NumConformancePathsRecorded;
   };
 
   // If this is the first time we're asked to look up a conformance access path,
   // visit all of the root conformance requirements in our generic signature and
   // add them to the buffer.
-  if (ConformanceAccessPaths.empty()) {
+  if (ConformancePaths.empty()) {
     for (const auto &req : Sig.getRequirements()) {
       // We only care about conformance requirements.
       if (req.getKind() != RequirementKind::Conformance)
@@ -543,9 +543,9 @@ RequirementMachine::getConformanceAccessPath(Type type,
       auto rootType = CanType(req.getFirstType());
       auto *rootProto = req.getProtocolDecl();
 
-      ConformanceAccessPath::Entry root(rootType, rootProto);
+      ConformancePath::Entry root(rootType, rootProto);
-      ArrayRef<ConformanceAccessPath::Entry> path(root);
+      ArrayRef<ConformancePath::Entry> path(root);
-      ConformanceAccessPath result(ctx.AllocateCopy(path));
+      ConformancePath result(ctx.AllocateCopy(path));
 
       auto mutTerm = Context.getMutableTermForType(rootType, nullptr);
       System.simplify(mutTerm);
@@ -555,17 +555,17 @@ RequirementMachine::getConformanceAccessPath(Type type,
     }
   }
 
-  // We enumerate conformance access paths in shortlex order until we find the
+  // We enumerate conformance paths in shortlex order until we find the
   // path whose corresponding type reduces to the one we are looking for.
   while (true) {
-    auto found = ConformanceAccessPaths.find(
+    auto found = ConformancePaths.find(
         std::make_pair(term, protocol));
-    if (found != ConformanceAccessPaths.end()) {
+    if (found != ConformancePaths.end()) {
       return found->second;
     }
 
-    if (CurrentConformanceAccessPaths.empty()) {
+    if (CurrentConformancePaths.empty()) {
-      llvm::errs() << "Failed to find conformance access path for ";
+      llvm::errs() << "Failed to find conformance path for ";
       llvm::errs() << type << " (" << term << ")" << " : ";
       llvm::errs() << protocol->getName() << ":\n";
       type.dump(llvm::errs());
@@ -574,18 +574,18 @@ RequirementMachine::getConformanceAccessPath(Type type,
       abort();
     }
 
-    // The buffer consists of all conformance access paths of length N.
+    // The buffer consists of all conformance paths of length N.
     // Swap it out with an empty buffer, and fill it with all paths of
     // length N+1.
-    std::vector<std::pair<Term, ConformanceAccessPath>> oldPaths;
+    std::vector<std::pair<Term, ConformancePath>> oldPaths;
-    std::swap(CurrentConformanceAccessPaths, oldPaths);
+    std::swap(CurrentConformancePaths, oldPaths);
 
     for (const auto &pair : oldPaths) {
       const auto &lastElt = pair.second.back();
       auto *lastProto = lastElt.second;
 
       // A copy of the current path, populated as needed.
-      SmallVector<ConformanceAccessPath::Entry, 4> entries;
+      SmallVector<ConformancePath::Entry, 4> entries;
 
       auto reqs = lastProto->getRequirementSignature().getRequirements();
       for (const auto &req : reqs) {
@@ -607,7 +607,7 @@ RequirementMachine::getConformanceAccessPath(Type type,
         // don't add it to the buffer. Note that because we iterate over
         // conformance access paths in shortlex order, the existing
         // conformance access path is shorter than the one we found just now.
-        if (ConformanceAccessPaths.count(
+        if (ConformancePaths.count(
                 std::make_pair(nextTerm, nextProto)))
           continue;
 
@@ -620,7 +620,7 @@ RequirementMachine::getConformanceAccessPath(Type type,
 
         // Add the next entry.
         entries.emplace_back(nextSubjectType, nextProto);
-        ConformanceAccessPath result = ctx.AllocateCopy(entries);
+        ConformancePath result = ctx.AllocateCopy(entries);
         entries.pop_back();
 
         recordPath(nextTerm, nextProto, result);

lib/AST/RequirementMachine/RequirementMachine.cpp

@@ -565,8 +565,8 @@ void RequirementMachine::dump(llvm::raw_ostream &out) const {
   System.dump(out);
   Map.dump(out);
 
-  out << "Conformance access paths: {\n";
+  out << "Conformance paths: {\n";
-  for (auto pair : ConformanceAccessPaths) {
+  for (auto pair : ConformancePaths) {
     out << "- " << pair.first.first << " : ";
     out << pair.first.second->getName() << " => ";
     pair.second.print(out);

lib/AST/RequirementMachine/RequirementMachine.h

@@ -71,16 +71,15 @@ class RequirementMachine final {
 
   UnifiedStatsReporter *Stats;
 
-  /// All conformance access paths computed so far.
+  /// All conformance paths computed so far.
   llvm::DenseMap<std::pair<Term, ProtocolDecl *>,
-                 ConformanceAccessPath> ConformanceAccessPaths;
+                 ConformancePath> ConformancePaths;
 
   /// Conformance access paths computed during the last round. All elements
   /// have the same length. If a conformance access path of greater length
-  /// is requested, we refill CurrentConformanceAccessPaths with all paths of
+  /// is requested, we refill CurrentConformancePaths with all paths of
-  /// length N+1, and add them to the ConformanceAccessPaths map.
+  /// length N+1, and add them to the ConformancePaths map.
-  std::vector<std::pair<Term, ConformanceAccessPath>>
+  std::vector<std::pair<Term, ConformancePath>> CurrentConformancePaths;
-      CurrentConformanceAccessPaths;
 
   explicit RequirementMachine(RewriteContext &rewriteCtx);
 
@@ -158,8 +157,7 @@ public:
   Type getReducedType(Type type,
                       TypeArrayView<GenericTypeParamType> genericParams) const;
   bool isValidTypeParameter(Type type) const;
-  ConformanceAccessPath getConformanceAccessPath(Type type,
+  ConformancePath getConformancePath(Type type, ProtocolDecl *protocol);
-                                                 ProtocolDecl *protocol);
   TypeDecl *lookupNestedType(Type depType, Identifier name) const;
 
   llvm::DenseMap<const ProtocolDecl *, RequirementSignature>

lib/AST/RequirementMachine/RequirementMachineRequests.cpp

@@ -482,7 +482,7 @@ RequirementMachine::computeMinimalGenericSignature(
   auto sig = GenericSignature::get(getGenericParams(), reqs);
 
   // Remember the signature for generic signature queries. In particular,
-  // getConformanceAccessPath() needs the current requirement machine's
+  // getConformancePath() needs the current requirement machine's
   // generic signature.
   Sig = sig.getCanonicalSignature();
 

lib/AST/SubstitutionMap.cpp

@@ -367,11 +367,10 @@ SubstitutionMap::lookupConformance(CanType type, ProtocolDecl *proto) const {
     return ProtocolConformanceRef::forMissingOrInvalid(substType, proto);
   }
 
-  auto accessPath =
+  auto path = genericSig->getConformancePath(type, proto);
-    genericSig->getConformanceAccessPath(type, proto);
 
   ProtocolConformanceRef conformance;
-  for (const auto &step : accessPath) {
+  for (const auto &step : path) {
     // For the first step, grab the initial conformance.
     if (conformance.isInvalid()) {
       if (auto initialConformance = getSignatureConformance(

lib/IRGen/GenArchetype.cpp

@@ -191,8 +191,7 @@ llvm::Value *irgen::emitArchetypeWitnessTableRef(IRGenFunction &IGF,
 
   auto environment = archetype->getGenericEnvironment();
 
-  // Otherwise, ask the generic signature for the environment for the best
+  // Otherwise, ask the generic signature for the best path to the conformance.
-  // path to the conformance.
   // TODO: this isn't necessarily optimal if the direct conformance isn't
   // concretely available; we really ought to be comparing the full paths
   // to this conformance from concrete sources.
@@ -200,8 +199,7 @@ llvm::Value *irgen::emitArchetypeWitnessTableRef(IRGenFunction &IGF,
   auto signature = environment->getGenericSignature().getCanonicalSignature();
   auto archetypeDepType = archetype->getInterfaceType();
 
-  auto astPath = signature->getConformanceAccessPath(archetypeDepType,
+  auto astPath = signature->getConformancePath(archetypeDepType, protocol);
-                                                     protocol);
 
   auto i = astPath.begin(), e = astPath.end();
   assert(i != e && "empty path!");