Merge pull request swiftlang#30439 from CodaFi/swift-is-an-untyped-languge-now-i-dont-make-the-rules

CodaFi · web-flow · commit ecb58a12d799 · 2020-03-16T21:17:45.000-07:00
[NFC] Break TypeChecker Down Into a Namespace
diff --git a/include/swift/AST/ASTContext.h b/include/swift/AST/ASTContext.h
@@ -105,7 +105,6 @@ namespace swift {
   class SourceManager;
   class ValueDecl;
   class DiagnosticEngine;
-  class TypeChecker;
   class TypeCheckerDebugConsumer;
   struct RawComment;
   class DocComment;
@@ -333,6 +332,32 @@ class ASTContext final {
   llvm::BumpPtrAllocator &
   getAllocator(AllocationArena arena = AllocationArena::Permanent) const;
 
+private:
+  bool SemanticQueriesEnabled = false;
+
+public:
+  /// Returns \c true if legacy semantic AST queries are enabled.
+  ///
+  /// The request evaluator generally subsumes the use of this bit. However,
+  /// there are clients - mostly SourceKit - that rely on the fact that this bit
+  /// being \c false causes some property wrapper requests to return null
+  /// sentinel values. These clients should be migrated off of this interface
+  /// to syntactic requests as soon as possible.
+  ///
+  /// rdar://60516325
+  bool areLegacySemanticQueriesEnabled() const {
+    return SemanticQueriesEnabled;
+  }
+
+  /// Enable "semantic queries".
+  ///
+  /// Setting this bit tells property wrapper requests to return a semantic
+  /// value.  It does not otherwise affect compiler behavior and should be
+  /// removed as soon as possible.
+  void setLegacySemanticQueriesEnabled() {
+    SemanticQueriesEnabled = true;
+  }
+
 public:
   /// Allocate - Allocate memory from the ASTContext bump pointer.
   void *Allocate(unsigned long bytes, unsigned alignment,
@@ -442,18 +467,7 @@ class ASTContext final {
   /// Set a new stats reporter.
   void setStatsReporter(UnifiedStatsReporter *stats);
 
-private:
-  friend class TypeChecker;
-
-  void installGlobalTypeChecker(TypeChecker *TC);
 public:
-  /// Returns if semantic AST queries are enabled. This generally means module
-  /// loading and name lookup can take place.
-  bool areSemanticQueriesEnabled() const;
-
-  /// Retrieve the global \c TypeChecker instance associated with this context.
-  TypeChecker *getLegacyGlobalTypeChecker() const;
-
   /// getIdentifier - Return the uniqued and AST-Context-owned version of the
   /// specified string.
   Identifier getIdentifier(StringRef Str) const;
diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
@@ -3597,7 +3597,6 @@ class EnumDecl final : public NominalTypeDecl {
 
   friend class EnumRawValuesRequest;
   friend class EnumRawTypeRequest;
-  friend class TypeChecker;
 
 public:
   EnumDecl(SourceLoc EnumLoc, Identifier Name, SourceLoc NameLoc,
@@ -3883,7 +3882,6 @@ class ClassDecl final : public NominalTypeDecl {
   friend class EmittedMembersRequest;
   friend class HasMissingDesignatedInitializersRequest;
   friend class InheritsSuperclassInitializersRequest;
-  friend class TypeChecker;
 
 public:
   ClassDecl(SourceLoc ClassLoc, Identifier Name, SourceLoc NameLoc,
@@ -4258,7 +4256,6 @@ class ProtocolDecl final : public NominalTypeDecl {
   friend class ProtocolRequiresClassRequest;
   friend class ExistentialConformsToSelfRequest;
   friend class ExistentialTypeSupportedRequest;
-  friend class TypeChecker;
 
 public:
   ProtocolDecl(DeclContext *DC, SourceLoc ProtocolLoc, SourceLoc NameLoc,
diff --git a/include/swift/AST/SourceFile.h b/include/swift/AST/SourceFile.h
@@ -267,6 +267,14 @@ class SourceFile final : public FileUnit {
   /// A set of synthesized declarations that need to be type checked.
   llvm::SmallVector<Decl *, 8> SynthesizedDecls;
 
+  /// The list of functions defined in this file whose bodies have yet to be
+  /// typechecked. They must be held in this list instead of eagerly validated
+  /// because their bodies may force us to perform semantic checks of arbitrary
+  /// complexity, and we currently cannot handle those checks in isolation. E.g.
+  /// we cannot, in general, perform witness matching on singular requirements
+  /// unless the entire conformance has been evaluated.
+  std::vector<AbstractFunctionDecl *> DelayedFunctions;
+
   /// We might perform type checking on the same source file more than once,
   /// if its the main file or a REPL instance, so keep track of the last
   /// checked synthesized declaration to avoid duplicating work.
diff --git a/include/swift/AST/TypeCheckRequests.h b/include/swift/AST/TypeCheckRequests.h
@@ -498,7 +498,6 @@ class MangleLocalTypeDeclRequest :
 };
 
 void simple_display(llvm::raw_ostream &out, const KnownProtocolKind);
-class TypeChecker;
 
 // Find the type in the cache or look it up
 class DefaultTypeRequest
diff --git a/include/swift/Sema/IDETypeChecking.h b/include/swift/Sema/IDETypeChecking.h
@@ -43,7 +43,6 @@ namespace swift {
   class SubscriptDecl;
   class TopLevelCodeDecl;
   class Type;
-  class TypeChecker;
   class ValueDecl;
   struct PrintOptions;
 
diff --git a/include/swift/Subsystems.h b/include/swift/Subsystems.h
@@ -66,7 +66,6 @@ namespace swift {
   class SyntaxParsingCache;
   class Token;
   class TopLevelContext;
-  class TypeChecker;
   class TypeCheckerOptions;
   struct TypeLoc;
   class UnifiedStatsReporter;
@@ -141,12 +140,6 @@ namespace swift {
   /// lib/Sema/PCMacro.cpp for a description of the calls inserted.
   void performPCMacro(SourceFile &SF);
 
-  /// Creates a type checker instance on the given AST context, if it
-  /// doesn't already have one.
-  ///
-  /// \returns a reference to the type checker instance.
-  TypeChecker &createTypeChecker(ASTContext &Ctx);
-
   /// Bind all 'extension' visible from \p SF to the extended nominal.
   void bindExtensions(SourceFile &SF);
 
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
@@ -155,9 +155,6 @@ struct ASTContext::Implementation {
   /// The set of cleanups to be called when the ASTContext is destroyed.
   std::vector<std::function<void(void)>> Cleanups;
 
-  /// A global type checker instance..
-  TypeChecker *Checker = nullptr;
-
   // FIXME: This is a StringMap rather than a StringSet because StringSet
   // doesn't allow passing in a pre-existing allocator.
   llvm::StringMap<Identifier::Aligner, llvm::BumpPtrAllocator&>
@@ -632,19 +629,6 @@ RC<syntax::SyntaxArena> ASTContext::getSyntaxArena() const {
   return getImpl().TheSyntaxArena;
 }
 
-bool ASTContext::areSemanticQueriesEnabled() const {
-  return getLegacyGlobalTypeChecker() != nullptr;
-}
-
-TypeChecker *ASTContext::getLegacyGlobalTypeChecker() const {
-  return getImpl().Checker;
-}
-
-void ASTContext::installGlobalTypeChecker(TypeChecker *TC) {
-  assert(!getImpl().Checker);
-  getImpl().Checker = TC;
-}
-
 /// getIdentifier - Return the uniqued and AST-Context-owned version of the
 /// specified string.
 Identifier ASTContext::getIdentifier(StringRef Str) const {
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
@@ -2998,7 +2998,7 @@ bool ValueDecl::isRecursiveValidation() const {
 Type ValueDecl::getInterfaceType() const {
   auto &ctx = getASTContext();
 
-  assert(ctx.areSemanticQueriesEnabled());
+  assert(ctx.areLegacySemanticQueriesEnabled());
 
   if (auto type =
           evaluateOrDefault(ctx.evaluator,
@@ -5813,7 +5813,7 @@ StaticSpellingKind AbstractStorageDecl::getCorrectStaticSpelling() const {
 
 llvm::TinyPtrVector<CustomAttr *> VarDecl::getAttachedPropertyWrappers() const {
   auto &ctx = getASTContext();
-  if (!ctx.areSemanticQueriesEnabled()) {
+  if (!ctx.areLegacySemanticQueriesEnabled()) {
     return { };
   }
 
@@ -6786,7 +6786,7 @@ ObjCSelector
 AbstractFunctionDecl::getObjCSelector(DeclName preferredName,
                                       bool skipIsObjCResolution) const {
   // FIXME: Forces computation of the Objective-C selector.
-  if (getASTContext().areSemanticQueriesEnabled() && !skipIsObjCResolution)
+  if (getASTContext().areLegacySemanticQueriesEnabled() && !skipIsObjCResolution)
     (void)isObjC();
 
   // If there is an @objc attribute with a name, use that name.
diff --git a/lib/AST/NameLookup.cpp b/lib/AST/NameLookup.cpp
@@ -1622,7 +1622,7 @@ QualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,
       tracker->addUsedMember({current, member.getBaseName()},isLookupCascading);
 
     // Make sure we've resolved property wrappers, if we need them.
-    if (ctx.areSemanticQueriesEnabled()) {
+    if (ctx.areLegacySemanticQueriesEnabled()) {
       installPropertyWrapperMembersIfNeeded(current, member);
     }
 
diff --git a/lib/Frontend/Frontend.cpp b/lib/Frontend/Frontend.cpp
@@ -240,7 +240,7 @@ bool CompilerInstance::setUpASTContextIfNeeded() {
   if (setUpModuleLoaders())
     return true;
 
-  createTypeChecker(*Context);
+  Context->setLegacySemanticQueriesEnabled();
   return false;
 }
 
diff --git a/lib/IDE/CodeCompletion.cpp b/lib/IDE/CodeCompletion.cpp
@@ -1638,7 +1638,7 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
         Importer(static_cast<ClangImporter *>(CurrDeclContext->getASTContext().
           getClangModuleLoader())),
         CompletionContext(CompletionContext) {
-    (void)swift::createTypeChecker(Ctx);
+    Ctx.setLegacySemanticQueriesEnabled();
 
     // Determine if we are doing code completion inside a static method.
     if (CurrDeclContext) {
@@ -4186,7 +4186,7 @@ class CompletionOverrideLookup : public swift::VisibleDeclConsumer {
                            SourceLoc introducerLoc)
       : Sink(Sink), Ctx(Ctx), CurrDeclContext(CurrDeclContext),
         ParsedKeywords(ParsedKeywords), introducerLoc(introducerLoc) {
-    (void)createTypeChecker(Ctx);
+    Ctx.setLegacySemanticQueriesEnabled();
 
     hasFuncIntroducer = isKeywordSpecified("func");
     hasVarIntroducer = isKeywordSpecified("var") ||
diff --git a/lib/Sema/CSGen.cpp b/lib/Sema/CSGen.cpp
@@ -4405,7 +4405,7 @@ getMemberDecls(InterestedMemberKind Kind) {
 ResolvedMemberResult
 swift::resolveValueMember(DeclContext &DC, Type BaseTy, DeclName Name) {
   ResolvedMemberResult Result;
-  assert(DC.getASTContext().areSemanticQueriesEnabled());
+  assert(DC.getASTContext().areLegacySemanticQueriesEnabled());
   ConstraintSystem CS(&DC, None);
 
   // Look up all members of BaseTy with the given Name.
diff --git a/lib/Sema/CodeSynthesis.h b/lib/Sema/CodeSynthesis.h
@@ -33,15 +33,12 @@ class ConstructorDecl;
 class FuncDecl;
 class GenericParamList;
 class NominalTypeDecl;
+class ObjCReason;
 class ParamDecl;
 class Type;
 class ValueDecl;
 class VarDecl;
 
-class TypeChecker;
-
-class ObjCReason;
-
 enum class SelfAccessorKind {
   /// We're building a derived accessor on top of whatever this
   /// class provides.
diff --git a/lib/Sema/ConstraintSystem.h b/lib/Sema/ConstraintSystem.h
@@ -2229,8 +2229,15 @@ class ConstraintSystem {
   /// constraint system for further exploration.
   void applySolution(const Solution &solution);
 
-  // FIXME: Allows the type checker to apply solutions.
-  friend class swift::TypeChecker;
+  // FIXME: Perhaps these belong on ConstraintSystem itself.
+  friend Optional<BraceStmt *>
+  swift::TypeChecker::applyFunctionBuilderBodyTransform(FuncDecl *func,
+                                                        Type builderType);
+  friend Optional<SolutionApplicationTarget>
+  swift::TypeChecker::typeCheckExpression(SolutionApplicationTarget &target,
+                                          bool &unresolvedTypeExprs,
+                                          TypeCheckExprOptions options,
+                                          ExprTypeCheckListener *listener);
 
   /// Emit the fixes computed as part of the solution, returning true if we were
   /// able to emit an error message, or false if none of the fixits worked out.
diff --git a/lib/Sema/DebuggerTestingTransform.cpp b/lib/Sema/DebuggerTestingTransform.cpp
@@ -243,7 +243,7 @@ class DebuggerTestingTransform : public ASTWalker {
     // TODO: typeCheckExpression() seems to assign types to everything here,
     // but may not be sufficient in some cases.
     Expr *FinalExpr = ClosureCall;
-    (void)swift::createTypeChecker(Ctx);
+    Ctx.setLegacySemanticQueriesEnabled();
     if (!TypeChecker::typeCheckExpression(FinalExpr, getCurrentDeclContext()))
       llvm::report_fatal_error("Could not type-check instrumentation");
 
diff --git a/lib/Sema/DerivedConformances.h b/lib/Sema/DerivedConformances.h
@@ -27,7 +27,6 @@ class AccessorDecl;
 class NominalTypeDecl;
 class PatternBindingDecl;
 class Type;
-class TypeChecker;
 class ValueDecl;
 class VarDecl;
 
diff --git a/lib/Sema/IDETypeCheckingRequests.cpp b/lib/Sema/IDETypeCheckingRequests.cpp
@@ -56,7 +56,7 @@ static bool isExtensionAppliedInternal(const DeclContext *DC, Type BaseTy,
   if (!ED->isConstrainedExtension())
     return true;
 
-  (void)swift::createTypeChecker(DC->getASTContext());
+  DC->getASTContext().setLegacySemanticQueriesEnabled();
   GenericSignature genericSig = ED->getGenericSignature();
   SubstitutionMap substMap = BaseTy->getContextSubstitutionMap(
       DC->getParentModule(), ED->getExtendedNominal());
diff --git a/lib/Sema/MiscDiagnostics.h b/lib/Sema/MiscDiagnostics.h
@@ -31,7 +31,6 @@ namespace swift {
   class InFlightDiagnostic;
   class Stmt;
   class TopLevelCodeDecl;
-  class TypeChecker;
   class ValueDecl;
 
 /// Emit diagnostics for syntactic restrictions on a given expression.
diff --git a/lib/Sema/TypeCheckAccess.h b/lib/Sema/TypeCheckAccess.h
@@ -20,7 +20,6 @@
 namespace swift {
 
 class Decl;
-class TypeChecker;
 
 /// Performs access-related checks for \p D.
 ///
diff --git a/lib/Sema/TypeCheckDeclPrimary.cpp b/lib/Sema/TypeCheckDeclPrimary.cpp
diff --git a/lib/Sema/TypeCheckObjC.h b/lib/Sema/TypeCheckObjC.h
diff --git a/lib/Sema/TypeCheckPropertyWrapper.cpp b/lib/Sema/TypeCheckPropertyWrapper.cpp
diff --git a/lib/Sema/TypeCheckProtocol.h b/lib/Sema/TypeCheckProtocol.h
diff --git a/lib/Sema/TypeChecker.cpp b/lib/Sema/TypeChecker.cpp
diff --git a/lib/Sema/TypeChecker.h b/lib/Sema/TypeChecker.h
diff --git a/lib/Sema/TypoCorrection.h b/lib/Sema/TypoCorrection.h
diff --git a/tools/SourceKit/lib/SwiftLang/SwiftDocSupport.cpp b/tools/SourceKit/lib/SwiftLang/SwiftDocSupport.cpp
diff --git a/tools/SourceKit/lib/SwiftLang/SwiftIndexing.cpp b/tools/SourceKit/lib/SwiftLang/SwiftIndexing.cpp

Original file line number	Diff line number	Diff line change
`@@ -1622,7 +1622,7 @@ QualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,`
`1622`	`1622`	`tracker->addUsedMember({current, member.getBaseName()},isLookupCascading);`
`1623`	`1623`
`1624`	`1624`	`// Make sure we've resolved property wrappers, if we need them.`
`1625`		`- if (ctx.areSemanticQueriesEnabled()) {`
	`1625`	`+ if (ctx.areLegacySemanticQueriesEnabled()) {`
`1626`	`1626`	`installPropertyWrapperMembersIfNeeded(current, member);`
`1627`	`1627`	`}`
`1628`	`1628`
Original file line number	Diff line number	Diff line change
`@@ -240,7 +240,7 @@ bool CompilerInstance::setUpASTContextIfNeeded() {`
`240`	`240`	`if (setUpModuleLoaders())`
`241`	`241`	`return true;`
`242`	`242`
`243`		`- createTypeChecker(*Context);`
	`243`	`+ Context->setLegacySemanticQueriesEnabled();`
`244`	`244`	`return false;`
`245`	`245`	`}`
`246`	`246`