Merge pull request #26876 from apple/revert-26478-gsoc-2019-parser-types

Revert "[Parser] Decouple the parser from AST creation (part 2)"

Author: rintaro

include/swift/Parse/ASTGen.h

@@ -14,108 +14,54 @@
 #define SWIFT_PARSE_ASTGEN_H
 
 #include "swift/AST/ASTContext.h"
-#include "swift/AST/Decl.h"
 #include "swift/AST/Expr.h"
-#include "swift/Parse/PersistentParserState.h"
 #include "swift/Syntax/SyntaxNodes.h"
 #include "llvm/ADT/DenseMap.h"
 
 namespace swift {
 /// Generates AST nodes from Syntax nodes.
 class ASTGen {
   ASTContext &Context;
-
-  /// Type cache to prevent multiple transformations of the same syntax node.
-  llvm::DenseMap<syntax::SyntaxNodeId, TypeRepr *> TypeCache;
-
-  PersistentParserState **ParserState;
-
-  // FIXME: remove when Syntax can represent all types and ASTGen can handle them
-  /// Types that cannot be represented by Syntax or generated by ASTGen.
-  llvm::DenseMap<SourceLoc, TypeRepr *> Types;
+  // A stack of source locations of syntax constructs. Allows us to get the
+  // SourceLoc necessary to create AST nodes for nodes in not-yet-complete
+  // Syntax tree. The topmost item should always correspond to the token/node
+  // that has been parsed/transformed most recently.
+  // todo [gsoc]: remove when possible
+  llvm::SmallVector<SourceLoc, 16> LocStack;
 
 public:
-  ASTGen(ASTContext &Context, PersistentParserState **ParserState)
-      : Context(Context), ParserState(ParserState) {}
-
-  SourceLoc generate(syntax::TokenSyntax Tok, SourceLoc &Loc);
-
-  Expr *generate(syntax::IntegerLiteralExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::FloatLiteralExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::NilLiteralExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::BooleanLiteralExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::PoundFileExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::PoundLineExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::PoundColumnExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::PoundFunctionExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::PoundDsohandleExprSyntax &Expr, SourceLoc &Loc);
-  Expr *generate(syntax::UnknownExprSyntax &Expr, SourceLoc &Loc);
-
-  TypeRepr *generate(syntax::TypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::SomeTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::CompositionTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::SimpleTypeIdentifierSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::MemberTypeIdentifierSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::DictionaryTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::ArrayTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::TupleTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::AttributedTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::FunctionTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::MetatypeTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::OptionalTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::ImplicitlyUnwrappedOptionalTypeSyntax Type, SourceLoc &Loc);
-  TypeRepr *generate(syntax::UnknownTypeSyntax Type, SourceLoc &Loc);
-
-  TypeRepr *generate(syntax::GenericArgumentSyntax Arg, SourceLoc &Loc);
-  llvm::SmallVector<TypeRepr *, 4>
-  generate(syntax::GenericArgumentListSyntax Args, SourceLoc &Loc);
+  explicit ASTGen(ASTContext &Context) : Context(Context) {}
+
+  IntegerLiteralExpr *generate(syntax::IntegerLiteralExprSyntax &Expr);
+  FloatLiteralExpr *generate(syntax::FloatLiteralExprSyntax &Expr);
+  NilLiteralExpr *generate(syntax::NilLiteralExprSyntax &Expr);
+  BooleanLiteralExpr *generate(syntax::BooleanLiteralExprSyntax &Expr);
+  MagicIdentifierLiteralExpr *generate(syntax::PoundFileExprSyntax &Expr);
+  MagicIdentifierLiteralExpr *generate(syntax::PoundLineExprSyntax &Expr);
+  MagicIdentifierLiteralExpr *generate(syntax::PoundColumnExprSyntax &Expr);
+  MagicIdentifierLiteralExpr *generate(syntax::PoundFunctionExprSyntax &Expr);
+  MagicIdentifierLiteralExpr *generate(syntax::PoundDsohandleExprSyntax &Expr);
+  Expr *generate(syntax::UnknownExprSyntax &Expr);
+
+  /// Stores source location necessary for AST creation.
+  void pushLoc(SourceLoc Loc);
 
   /// Copy a numeric literal value into AST-owned memory, stripping underscores
   /// so the semantic part of the value can be parsed by APInt/APFloat parsers.
   static StringRef copyAndStripUnderscores(StringRef Orig, ASTContext &Context);
 
 private:
-  Expr *generateMagicIdentifierLiteralExpression(syntax::TokenSyntax PoundToken,
-                                                 SourceLoc &Loc);
-
-  TupleTypeRepr *generateTuple(syntax::TokenSyntax LParen,
-                               syntax::TupleTypeElementListSyntax Elements,
-                               syntax::TokenSyntax RParen, SourceLoc &Loc,
-                               bool IsFunction = false);
-
-  void gatherTypeIdentifierComponents(
-      syntax::TypeSyntax Component, SourceLoc &Loc,
-      llvm::SmallVectorImpl<ComponentIdentTypeRepr *> &Components);
-
-  template <typename T>
-  TypeRepr *generateSimpleOrMemberIdentifier(T Type, SourceLoc &Loc);
-
-  template <typename T>
-  ComponentIdentTypeRepr *generateIdentifier(T Type, SourceLoc &Loc);
-
   StringRef copyAndStripUnderscores(StringRef Orig);
 
-  static SourceLoc advanceLocBegin(const SourceLoc &Loc,
-                                   const syntax::Syntax &Node);
-  static SourceLoc advanceLocEnd(const SourceLoc &Loc,
-                                 const syntax::TokenSyntax &Token);
-  static SourceLoc advanceLocAfter(const SourceLoc &Loc,
-                                   const syntax::Syntax &Node);
-
-  static MagicIdentifierLiteralExpr::Kind getMagicIdentifierLiteralKind(tok Kind);
-
-  ValueDecl *lookupInScope(DeclName Name);
-
-  TypeRepr *cacheType(syntax::TypeSyntax Type, TypeRepr *TypeAST);
-
-  TypeRepr *lookupType(syntax::TypeSyntax Type);
-
-public:
-  TypeRepr *addType(TypeRepr *Type, const SourceLoc &Loc);
+  SourceLoc topLoc();
 
-  bool hasType(const SourceLoc &Loc) const;
+  MagicIdentifierLiteralExpr *
+  generateMagicIdentifierLiteralExpr(const syntax::TokenSyntax &PoundToken);
 
-  TypeRepr *getType(const SourceLoc &Loc) const;
+  /// Map magic literal tokens such as #file to their MagicIdentifierLiteralExpr
+  /// kind.
+  static MagicIdentifierLiteralExpr::Kind
+  getMagicIdentifierLiteralKind(tok Kind);
 };
 } // namespace swift
 

include/swift/Parse/ParsedRawSyntaxNode.h

@@ -136,20 +136,9 @@ class ParsedRawSyntaxNode {
   /// Primary used for a deferred missing token.
   bool isMissing() const { return IsMissing; }
 
-  CharSourceRange getDeferredRange() const {
-    switch (DK) { 
-    case DataKind::DeferredLayout:
-      return getDeferredLayoutRange();
-    case DataKind::DeferredToken:
-      return getDeferredTokenRangeWithoutBackticks();
-    default:
-      llvm_unreachable("node not deferred");
-    }
-  }
-  
   // Recorded Data ===========================================================//
 
-  CharSourceRange getRecordedRange() const {
+  CharSourceRange getRange() const {
     assert(isRecorded());
     return RecordedData.Range;
   }
@@ -160,20 +149,6 @@ class ParsedRawSyntaxNode {
 
   // Deferred Layout Data ====================================================//
 
-  CharSourceRange getDeferredLayoutRange() const {
-    assert(DK == DataKind::DeferredLayout);
-    assert(!DeferredLayout.Children.empty());
-    auto getLastNonNullChild = [this]() {
-      for (auto &&Child : llvm::reverse(getDeferredChildren()))
-        if (!Child.isNull())
-          return Child;
-      llvm_unreachable("layout node without non-null children");
-    };
-    auto firstRange = DeferredLayout.Children.front().getDeferredRange();
-    auto lastRange = getLastNonNullChild().getDeferredRange();
-    firstRange.widen(lastRange);
-    return firstRange;
-  }
   ArrayRef<ParsedRawSyntaxNode> getDeferredChildren() const {
     assert(DK == DataKind::DeferredLayout);
     return DeferredLayout.Children;