[Parse/CodeCompletion] Cleanup code completion facilities in Parse

rintaro · rintaro · commit cd8ebe49bbb6 · 2019-11-13T03:21:03.000+09:00
- Rename code completion related names in 'PersistentParserState' so
  it's clear when you are using.
- Refactor 'performCodeCompletionSecondPass()': Inline and consolidate
  'parse*Delayed()' because they used to share many code.

rdar://problem/56926367
diff --git a/include/swift/Parse/Parser.h b/include/swift/Parse/Parser.h
@@ -43,6 +43,7 @@ namespace llvm {
 
 namespace swift {
   class CodeCompletionCallbacks;
+  class CodeCompletionCallbacksFactory;
   class DefaultArgumentInitializer;
   class DiagnosticEngine;
   class Expr;
@@ -867,8 +868,6 @@ class Parser {
                                    BraceItemListKind::Brace);
   ParserResult<BraceStmt> parseBraceItemList(Diag<> ID);
   
-  void parseTopLevelCodeDeclDelayed();
-
   //===--------------------------------------------------------------------===//
   // Decl Parsing
 
@@ -919,8 +918,6 @@ class Parser {
                                bool IsAtStartOfLineOrPreviousHadSemi,
                                llvm::function_ref<void(Decl*)> Handler);
 
-  void parseDeclDelayed();
-
   std::vector<Decl *> parseDeclListDelayed(IterableDeclContext *IDC);
 
   bool parseMemberDeclList(SourceLoc LBLoc, SourceLoc &RBLoc,
@@ -1089,7 +1086,6 @@ class Parser {
                                        bool HasFuncKeyword = true);
   void parseAbstractFunctionBody(AbstractFunctionDecl *AFD);
   BraceStmt *parseAbstractFunctionBodyDelayed(AbstractFunctionDecl *AFD);
-  void parseAbstractFunctionBodyDelayed();
   ParserResult<ProtocolDecl> parseDeclProtocol(ParseDeclOptions Flags,
                                                DeclAttributes &Attributes);
 
@@ -1583,6 +1579,16 @@ class Parser {
   parsePlatformVersionConstraintSpec();
   ParserResult<PlatformAgnosticVersionConstraintAvailabilitySpec>
   parsePlatformAgnosticVersionConstraintSpec();
+
+  //===--------------------------------------------------------------------===//
+  // Code completion second pass.
+
+  static void
+  performCodeCompletionSecondPass(PersistentParserState &ParserState,
+                                  CodeCompletionCallbacksFactory &Factory);
+
+  void performCodeCompletionSecondPassImpl(
+      PersistentParserState::CodeCompletionDelayedDeclState &info);
 };
 
 /// Describes a parsed declaration name.
diff --git a/include/swift/Parse/PersistentParserState.h b/include/swift/Parse/PersistentParserState.h
@@ -17,7 +17,6 @@
 #ifndef SWIFT_PARSE_PERSISTENTPARSERSTATE_H
 #define SWIFT_PARSE_PERSISTENTPARSERSTATE_H
 
-#include "swift/AST/LazyResolver.h"
 #include "swift/Basic/SourceLoc.h"
 #include "swift/Parse/LocalContext.h"
 #include "swift/Parse/ParserPosition.h"
@@ -26,6 +25,10 @@
 
 namespace swift {
 
+class SourceFile;
+class DeclContext;
+class IterableDeclContext;
+
 /// Parser state persistent across multiple parses.
 class PersistentParserState {
 public:
@@ -36,16 +39,16 @@ class PersistentParserState {
     bool isValid() const { return Loc.isValid(); }
   };
 
-  enum class DelayedDeclKind {
+  enum class CodeCompletionDelayedDeclKind {
     TopLevelCodeDecl,
     Decl,
     FunctionBody,
   };
 
-  class DelayedDeclState {
+  class CodeCompletionDelayedDeclState {
     friend class PersistentParserState;
     friend class Parser;
-    DelayedDeclKind Kind;
+    CodeCompletionDelayedDeclKind Kind;
     unsigned Flags;
     DeclContext *ParentContext;
     ParserPos BodyPos;
@@ -57,13 +60,13 @@ class PersistentParserState {
     }
 
   public:
-    DelayedDeclState(DelayedDeclKind Kind, unsigned Flags,
-                     DeclContext *ParentContext, SourceRange BodyRange,
-                     SourceLoc PreviousLoc, SavedScope &&Scope)
-      : Kind(Kind), Flags(Flags), ParentContext(ParentContext),
-        BodyPos{BodyRange.Start, PreviousLoc},
-        BodyEnd(BodyRange.End), Scope(std::move(Scope))
-    {}
+    CodeCompletionDelayedDeclState(CodeCompletionDelayedDeclKind Kind,
+                                   unsigned Flags, DeclContext *ParentContext,
+                                   SourceRange BodyRange, SourceLoc PreviousLoc,
+                                   SavedScope &&Scope)
+        : Kind(Kind), Flags(Flags),
+          ParentContext(ParentContext), BodyPos{BodyRange.Start, PreviousLoc},
+          BodyEnd(BodyRange.End), Scope(std::move(Scope)) {}
   };
 
   bool InPoundLineEnvironment = false;
@@ -76,7 +79,7 @@ class PersistentParserState {
   /// Parser sets this if it stopped parsing before the buffer ended.
   ParserPosition MarkedPos;
 
-  std::unique_ptr<DelayedDeclState> CodeCompletionDelayedDeclState;
+  std::unique_ptr<CodeCompletionDelayedDeclState> CodeCompletionDelayedDeclStat;
 
   std::vector<IterableDeclContext *> DelayedDeclLists;
 
@@ -89,28 +92,24 @@ class PersistentParserState {
   PersistentParserState(ASTContext &ctx) : PersistentParserState() { }
   ~PersistentParserState();
 
-  void delayDecl(DelayedDeclKind Kind, unsigned Flags,
-                 DeclContext *ParentContext,
-                 SourceRange BodyRange, SourceLoc PreviousLoc);
-
-  void delayDeclList(IterableDeclContext *D);
+  void setCodeCompletionDelayedDeclState(CodeCompletionDelayedDeclKind Kind,
+                                         unsigned Flags,
+                                         DeclContext *ParentContext,
+                                         SourceRange BodyRange,
+                                         SourceLoc PreviousLoc);
 
-  bool hasDelayedDecl() {
-    return CodeCompletionDelayedDeclState.get() != nullptr;
-  }
-  DelayedDeclKind getDelayedDeclKind() {
-    return CodeCompletionDelayedDeclState->Kind;
-  }
-  SourceLoc getDelayedDeclLoc() {
-    return CodeCompletionDelayedDeclState->BodyPos.Loc;
+  bool hasCodeCompletionDelayedDeclState() {
+    return CodeCompletionDelayedDeclStat.get() != nullptr;
   }
-  DeclContext *getDelayedDeclContext() {
-    return CodeCompletionDelayedDeclState->ParentContext;
-  }
-  std::unique_ptr<DelayedDeclState> takeDelayedDeclState() {
-    return std::move(CodeCompletionDelayedDeclState);
+
+  std::unique_ptr<CodeCompletionDelayedDeclState>
+  takeCodeCompletionDelayedDeclState() {
+    assert(hasCodeCompletionDelayedDeclState());
+    return std::move(CodeCompletionDelayedDeclStat);
   }
 
+  void delayDeclList(IterableDeclContext *D);
+
   void parseAllDelayedDeclLists();
 
   TopLevelContext &getTopLevelContext() {
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
@@ -3008,9 +3008,10 @@ void Parser::consumeDecl(ParserPosition BeginParserPosition,
   backtrackToPosition(BeginParserPosition);
   SourceLoc BeginLoc = Tok.getLoc();
 
-  State->delayDecl(PersistentParserState::DelayedDeclKind::Decl, Flags.toRaw(),
-                   CurDeclContext, {BeginLoc, EndLoc},
-                   BeginParserPosition.PreviousLoc);
+  State->setCodeCompletionDelayedDeclState(
+      PersistentParserState::CodeCompletionDelayedDeclKind::Decl,
+      Flags.toRaw(), CurDeclContext, {BeginLoc, EndLoc},
+      BeginParserPosition.PreviousLoc);
 
   while (SourceMgr.isBeforeInBuffer(Tok.getLoc(), CurrentLoc))
     consumeToken();
@@ -3575,48 +3576,6 @@ std::vector<Decl *> Parser::parseDeclListDelayed(IterableDeclContext *IDC) {
   return parseDeclList(LBLoc, RBLoc, Id, Options, IDC, hadError);
 }
 
-void Parser::parseDeclDelayed() {
-  auto DelayedState = State->takeDelayedDeclState();
-  assert(DelayedState.get() && "should have delayed state");
-
-  auto BeginParserPosition = getParserPosition(DelayedState->BodyPos);
-  auto EndLexerState = L->getStateForEndOfTokenLoc(DelayedState->BodyEnd);
-
-  // ParserPositionRAII needs a primed parser to restore to.
-  if (Tok.is(tok::NUM_TOKENS))
-    consumeTokenWithoutFeedingReceiver();
-
-  // Ensure that we restore the parser state at exit.
-  ParserPositionRAII PPR(*this);
-
-  // Create a lexer that cannot go past the end state.
-  Lexer LocalLex(*L, BeginParserPosition.LS, EndLexerState);
-
-  // Temporarily swap out the parser's current lexer with our new one.
-  llvm::SaveAndRestore<Lexer *> T(L, &LocalLex);
-
-  // Rewind to the beginning of the decl.
-  restoreParserPosition(BeginParserPosition);
-
-  // Re-enter the lexical scope.
-  Scope S(this, DelayedState->takeScope());
-  ContextChange CC(*this, DelayedState->ParentContext);
-
-  parseDecl(ParseDeclOptions(DelayedState->Flags),
-            /*IsAtStartOfLineOrPreviousHadSemi=*/true,
-            [&](Decl *D) {
-    if (auto *parent = DelayedState->ParentContext) {
-      if (auto *NTD = dyn_cast<NominalTypeDecl>(parent)) {
-        NTD->addMember(D);
-      } else if (auto *ED = dyn_cast<ExtensionDecl>(parent)) {
-        ED->addMember(D);
-      } else if (auto *SF = dyn_cast<SourceFile>(parent)) {
-        SF->Decls.push_back(D);
-      }
-    }
-  });
-}
-
 /// Parse an 'import' declaration, doing no token skipping on error.
 ///
 /// \verbatim
@@ -5640,9 +5599,9 @@ void Parser::consumeAbstractFunctionBody(AbstractFunctionDecl *AFD,
 
   if (isCodeCompletionFirstPass()) {
     if (SourceMgr.rangeContainsCodeCompletionLoc(BodyRange)) {
-      State->delayDecl(PersistentParserState::DelayedDeclKind::FunctionBody,
-                       PD_Default, AFD, BodyRange,
-                       BeginParserPosition.PreviousLoc);
+      State->setCodeCompletionDelayedDeclState(
+          PersistentParserState::CodeCompletionDelayedDeclKind::FunctionBody,
+          PD_Default, AFD, BodyRange, BeginParserPosition.PreviousLoc);
     } else {
       AFD->setBodySkipped(BodyRange);
     }
@@ -5957,20 +5916,6 @@ BraceStmt *Parser::parseAbstractFunctionBodyDelayed(AbstractFunctionDecl *AFD) {
   return parseBraceItemList(diag::func_decl_without_brace).getPtrOrNull();
 }
 
-/// Parse a delayed function body from the 'PersistentParserState'.
-void Parser::parseAbstractFunctionBodyDelayed() {
-  auto DelayedState = State->takeDelayedDeclState();
-  assert(DelayedState.get() && "should have delayed state");
-  auto CD = DelayedState->ParentContext->getAsDecl();
-  auto AFD = cast<AbstractFunctionDecl>(CD);
-
-  // Eagarly parse local decls or nested function bodies inside the body.
-  llvm::SaveAndRestore<bool> DisableDelayedBody(DelayBodyParsing, false);
-
-  auto body = parseAbstractFunctionBodyDelayed(AFD);
-  AFD->setBodyParsed(body);
-}
-
 /// Parse a 'enum' declaration, returning true (and doing no token
 /// skipping) on error.
 ///
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
@@ -256,9 +256,9 @@ void Parser::consumeTopLevelDecl(ParserPosition BeginParserPosition,
   SourceLoc EndLoc = PreviousLoc;
   backtrackToPosition(BeginParserPosition);
   SourceLoc BeginLoc = Tok.getLoc();
-  State->delayDecl(PersistentParserState::DelayedDeclKind::TopLevelCodeDecl,
-                   PD_Default, TLCD, {BeginLoc, EndLoc},
-                   BeginParserPosition.PreviousLoc);
+  State->setCodeCompletionDelayedDeclState(
+      PersistentParserState::CodeCompletionDelayedDeclKind::TopLevelCodeDecl,
+      PD_Default, TLCD, {BeginLoc, EndLoc}, BeginParserPosition.PreviousLoc);
 
   // Skip the rest of the file to prevent the parser from constructing the AST
   // for it.  Forward references are not allowed at the top level.
@@ -520,53 +520,6 @@ ParserStatus Parser::parseBraceItems(SmallVectorImpl<ASTNode> &Entries,
   return BraceItemsStatus;
 }
 
-void Parser::parseTopLevelCodeDeclDelayed() {
-  auto DelayedState = State->takeDelayedDeclState();
-  assert(DelayedState.get() && "should have delayed state");
-
-  auto BeginParserPosition = getParserPosition(DelayedState->BodyPos);
-  auto EndLexerState = L->getStateForEndOfTokenLoc(DelayedState->BodyEnd);
-
-  // ParserPositionRAII needs a primed parser to restore to.
-  if (Tok.is(tok::NUM_TOKENS))
-    consumeTokenWithoutFeedingReceiver();
-
-  // Ensure that we restore the parser state at exit.
-  ParserPositionRAII PPR(*this);
-
-  // Create a lexer that cannot go past the end state.
-  Lexer LocalLex(*L, BeginParserPosition.LS, EndLexerState);
-
-  // Temporarily swap out the parser's current lexer with our new one.
-  llvm::SaveAndRestore<Lexer *> T(L, &LocalLex);
-
-  // Rewind to the beginning of the top-level code.
-  restoreParserPosition(BeginParserPosition);
-
-  // Re-enter the lexical scope.
-  Scope S(this, DelayedState->takeScope());
-
-  // Re-enter the top-level decl context.
-  // FIXME: this can issue discriminators out-of-order?
-  auto *TLCD = cast<TopLevelCodeDecl>(DelayedState->ParentContext);
-  ContextChange CC(*this, TLCD, &State->getTopLevelContext());
-
-  SourceLoc StartLoc = Tok.getLoc();
-  ASTNode Result;
-
-  // Expressions can't begin with a closure literal at statement position. This
-  // prevents potential ambiguities with trailing closure syntax.
-  if (Tok.is(tok::l_brace)) {
-    diagnose(Tok, diag::statement_begins_with_closure);
-  }
-
-  parseExprOrStmt(Result);
-  if (!Result.isNull()) {
-    auto Brace = BraceStmt::create(Context, StartLoc, Result, Tok.getLoc());
-    TLCD->setBody(Brace);
-  }
-}
-
 /// Recover from a 'case' or 'default' outside of a 'switch' by consuming up to
 /// the next ':'.
 static ParserResult<Stmt> recoverFromInvalidCase(Parser &P) {
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
diff --git a/lib/Parse/PersistentParserState.cpp b/lib/Parse/PersistentParserState.cpp
