AST: Remove legacy GSB-based GenericSignature query implementation

include/swift/AST/ASTContext.h

@@ -95,7 +95,6 @@ namespace swift {
   class TypeVariableType;
   class TupleType;
   class FunctionType;
-  class GenericSignatureBuilder;
   class ArchetypeType;
   class Identifier;
   class InheritedNameSet;
@@ -1225,26 +1224,13 @@ class ASTContext final {
   /// Increments \c NumTypoCorrections then checks this against the limit in
   /// the language options.
   bool shouldPerformTypoCorrection();
-
-private:
-  /// Register the given generic signature builder to be used as the canonical
-  /// generic signature builder for the given signature, if we don't already
-  /// have one.
-  void registerGenericSignatureBuilder(GenericSignature sig,
-                                       GenericSignatureBuilder &&builder);
-  friend class GenericSignatureBuilder;
 
 private:
   friend class IntrinsicInfo;
   /// Retrieve an LLVMContext that is used for scratch space for intrinsic lookup.
   llvm::LLVMContext &getIntrinsicScratchContext() const;
 
 public:
-  /// Retrieve or create the stored generic signature builder for the given
-  /// canonical generic signature and module.
-  GenericSignatureBuilder *getOrCreateGenericSignatureBuilder(
-                                                     CanGenericSignature sig);
-
   rewriting::RewriteContext &getRewriteContext();
 
   /// This is a hack to break cycles. Don't introduce new callers of this

include/swift/AST/GenericSignature.h

@@ -30,7 +30,6 @@
 
 namespace swift {
 
-class GenericSignatureBuilder;
 class ProtocolConformanceRef;
 class ProtocolType;
 class SubstitutionMap;
@@ -84,7 +83,6 @@ class ConformanceAccessPath {
   ConformanceAccessPath(ArrayRef<Entry> path) : path(path) {}
 
   friend class GenericSignatureImpl;
-  friend class GenericSignatureBuilder;
   friend class rewriting::RequirementMachine;
 
 public:
@@ -338,9 +336,6 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
 
   ASTContext &getASTContext() const;
 
-  /// Retrieve the generic signature builder for the given generic signature.
-  GenericSignatureBuilder *getGenericSignatureBuilder() const;
-
   /// Retrieve the requirement machine for the given generic signature.
   rewriting::RequirementMachine *getRequirementMachine() const;
 
@@ -385,8 +380,6 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
   ///
   /// The type parameters must be known to not be concrete within the context.
   bool areSameTypeParameterInContext(Type type1, Type type2) const;
-  bool areSameTypeParameterInContext(Type type1, Type type2,
-                                     GenericSignatureBuilder &builder) const;
 
   /// Determine if \c sig can prove \c requirement, meaning that it can deduce
   /// T: Foo or T == U (etc.) with the information it knows. This includes
@@ -396,8 +389,6 @@ class alignas(1 << TypeAlignInBits) GenericSignatureImpl final
       Requirement requirement, bool allowMissing = false) const;
 
   bool isCanonicalTypeInContext(Type type) const;
-  bool isCanonicalTypeInContext(Type type,
-                                GenericSignatureBuilder &builder) const;
 
   /// Retrieve the conformance access path used to extract the conformance of
   /// interface \c type to the given \c protocol.

include/swift/Basic/LangOptions.h

@@ -477,10 +477,6 @@ namespace swift {
     ASTVerifierOverrideKind ASTVerifierOverride =
         ASTVerifierOverrideKind::NoOverride;
 
-    /// Whether the new experimental generics implementation is enabled.
-    RequirementMachineMode EnableRequirementMachine =
-        RequirementMachineMode::Enabled;
-
     /// Enables merged associated type support, which might go away.
     bool RequirementMachineMergedAssociatedTypes = true;
 

include/swift/Option/Options.td

@@ -616,10 +616,6 @@ def no_emit_module_separately:
   Flags<[NoInteractiveOption, HelpHidden]>,
   HelpText<"Force using merge-module as the incremental build mode (new Driver only)">;
 
-def requirement_machine_EQ : Joined<["-"], "requirement-machine=">,
-  Flags<[FrontendOption, ModuleInterfaceOption]>,
-  HelpText<"Control usage of experimental generics implementation: 'on', 'off', or 'verify'">;
-
 def requirement_machine_protocol_signatures_EQ : Joined<["-"], "requirement-machine-protocol-signatures=">,
   Flags<[FrontendOption]>,
   HelpText<"Control usage of experimental protocol requirement signature minimization: 'on', 'off', or 'verify'">;

lib/AST/ASTContext.cpp

@@ -17,7 +17,6 @@
 #include "swift/AST/ASTContext.h"
 #include "ClangTypeConverter.h"
 #include "ForeignRepresentationInfo.h"
-#include "GenericSignatureBuilder.h"
 #include "SubstitutionMapStorage.h"
 #include "swift/AST/ClangModuleLoader.h"
 #include "swift/AST/ConcreteDeclRef.h"
@@ -72,17 +71,9 @@
 using namespace swift;
 
 #define DEBUG_TYPE "ASTContext"
-STATISTIC(NumRegisteredGenericSignatureBuilders,
-          "# of generic signature builders successfully registered");
-STATISTIC(NumRegisteredGenericSignatureBuildersAlready,
-          "# of generic signature builders already registered");
 STATISTIC(NumCollapsedSpecializedProtocolConformances,
           "# of specialized protocol conformances collapsed");
 
-/// Define this to 1 to enable expensive assertions of the
-/// GenericSignatureBuilder.
-#define SWIFT_GSB_EXPENSIVE_ASSERTIONS 0
-
 void ModuleLoader::anchor() {}
 void ClangModuleLoader::anchor() {}
 
@@ -480,10 +471,6 @@ struct ASTContext::Implementation {
 
   llvm::FoldingSet<GenericSignatureImpl> GenericSignatures;
 
-  /// Stored generic signature builders for canonical generic signatures.
-  llvm::DenseMap<GenericSignature, std::unique_ptr<GenericSignatureBuilder>>
-    GenericSignatureBuilders;
-
   /// A cache of information about whether particular nominal types
   /// are representable in a foreign language.
   llvm::DenseMap<NominalTypeDecl *, ForeignRepresentationInfo>
@@ -1938,111 +1925,6 @@ void ASTContext::addLoadedModule(ModuleDecl *M) {
   getImpl().LoadedModules[M->getRealName()] = M;
 }
 
-void ASTContext::registerGenericSignatureBuilder(
-                                       GenericSignature sig,
-                                       GenericSignatureBuilder &&builder) {
-  if (LangOpts.EnableRequirementMachine == RequirementMachineMode::Enabled)
-    return;
-
-  auto canSig = sig.getCanonicalSignature();
-  auto &genericSignatureBuilders = getImpl().GenericSignatureBuilders;
-  auto known = genericSignatureBuilders.find(canSig);
-  if (known != genericSignatureBuilders.end()) {
-    ++NumRegisteredGenericSignatureBuildersAlready;
-    return;
-  }
-
-  ++NumRegisteredGenericSignatureBuilders;
-  genericSignatureBuilders[canSig] =
-    std::make_unique<GenericSignatureBuilder>(std::move(builder));
-}
-
-GenericSignatureBuilder *ASTContext::getOrCreateGenericSignatureBuilder(
-                                                      CanGenericSignature sig) {
-  // We should only create GenericSignatureBuilders if the requirement machine
-  // mode is ::Disabled or ::Verify.
-  assert(LangOpts.EnableRequirementMachine != RequirementMachineMode::Enabled &&
-         "Shouldn't create GenericSignatureBuilder when RequirementMachine "
-         "is enabled");
-
-  // Check whether we already have a generic signature builder for this
-  // signature and module.
-  auto &genericSignatureBuilders = getImpl().GenericSignatureBuilders;
-  auto known = genericSignatureBuilders.find(sig);
-  if (known != genericSignatureBuilders.end())
-    return known->second.get();
-
-  // Create a new generic signature builder with the given signature.
-  auto builder = new GenericSignatureBuilder(*this);
-
-  // Store this generic signature builder (no generic environment yet).
-  genericSignatureBuilders[sig] =
-    std::unique_ptr<GenericSignatureBuilder>(builder);
-
-  builder->addGenericSignature(sig);
-
-#if SWIFT_GSB_EXPENSIVE_ASSERTIONS
-  auto builderSig =
-    builder->computeGenericSignature(/*allowConcreteGenericParams=*/true);
-  if (builderSig.getCanonicalSignature() != sig) {
-    llvm::errs() << "ERROR: generic signature builder is not idempotent.\n";
-    llvm::errs() << "Original generic signature   : ";
-    sig->print(llvm::errs());
-    llvm::errs() << "\nReprocessed generic signature: ";
-    auto reprocessedSig = builderSig.getCanonicalSignature();
-
-    reprocessedSig->print(llvm::errs());
-    llvm::errs() << "\n";
-
-    if (sig.getGenericParams().size() ==
-          reprocessedSig.getGenericParams().size() &&
-        sig.getRequirements().size() ==
-          reprocessedSig.getRequirements().size()) {
-      for (unsigned i : indices(sig.getRequirements())) {
-        auto sigReq = sig.getRequirements()[i];
-        auto reprocessedReq = reprocessedSig.getRequirements()[i];
-        if (sigReq.getKind() != reprocessedReq.getKind()) {
-          llvm::errs() << "Requirement mismatch:\n";
-          llvm::errs() << "  Original: ";
-          sigReq.print(llvm::errs(), PrintOptions());
-          llvm::errs() << "\n  Reprocessed: ";
-          reprocessedReq.print(llvm::errs(), PrintOptions());
-          llvm::errs() << "\n";
-          break;
-        }
-
-        if (!sigReq.getFirstType()->isEqual(reprocessedReq.getFirstType())) {
-          llvm::errs() << "First type mismatch, original is:\n";
-          sigReq.getFirstType().dump(llvm::errs());
-          llvm::errs() << "Reprocessed:\n";
-          reprocessedReq.getFirstType().dump(llvm::errs());
-          llvm::errs() << "\n";
-          break;
-        }
-
-        if (sigReq.getKind() == RequirementKind::SameType &&
-            !sigReq.getSecondType()->isEqual(reprocessedReq.getSecondType())) {
-          llvm::errs() << "Second type mismatch, original is:\n";
-          sigReq.getSecondType().dump(llvm::errs());
-          llvm::errs() << "Reprocessed:\n";
-          reprocessedReq.getSecondType().dump(llvm::errs());
-          llvm::errs() << "\n";
-          break;
-        }
-      }
-    }
-
-    llvm_unreachable("idempotency problem with a generic signature");
-  }
-#else
-  // FIXME: This should be handled lazily in the future, and therefore not
-  // required.
-  builder->processDelayedRequirements();
-#endif
-
-  return builder;
-}
-
 rewriting::RewriteContext &
 ASTContext::getRewriteContext() {
   auto &rewriteCtx = getImpl().TheRewriteContext;