[Parse] Make parseDeclVar() always return the ParserResult for PatternBindingDecl

Author: rintaro

include/swift/Parse/Parser.h

@@ -743,11 +743,12 @@ class Parser {
   ParserResult<ClassDecl>
   parseDeclClass(SourceLoc ClassLoc,
                  ParseDeclOptions Flags, DeclAttributes &Attributes);
-  ParserStatus parseDeclVar(ParseDeclOptions Flags, DeclAttributes &Attributes,
-                            SmallVectorImpl<Decl *> &Decls,
-                            SourceLoc StaticLoc,
-                            StaticSpellingKind StaticSpelling,
-                            SourceLoc TryLoc);
+  ParserResult<PatternBindingDecl>
+  parseDeclVar(ParseDeclOptions Flags, DeclAttributes &Attributes,
+               SmallVectorImpl<Decl *> &Decls,
+               SourceLoc StaticLoc,
+               StaticSpellingKind StaticSpelling,
+               SourceLoc TryLoc);
 
   void consumeGetSetBody(AbstractFunctionDecl *AFD, SourceLoc LBLoc);
 

lib/Parse/ParseDecl.cpp

@@ -2239,11 +2239,14 @@ ParserStatus Parser::parseDecl(ParseDeclOptions Flags,
     case tok::kw_let:
     case tok::kw_var: {
       llvm::SmallVector<Decl *, 4> Entries;
-      Status = parseDeclVar(Flags, Attributes, Entries, StaticLoc,
-                            StaticSpelling, tryLoc);
+      DeclResult = parseDeclVar(Flags, Attributes, Entries, StaticLoc,
+                                StaticSpelling, tryLoc);
+      Status = DeclResult;
       StaticLoc = SourceLoc();   // we handled static if present.
       MayNeedOverrideCompletion = true;
       std::for_each(Entries.begin(), Entries.end(), InternalHandler);
+      if (auto *D = DeclResult.getPtrOrNull())
+        markWasHandled(D);
       break;
     }
     case tok::kw_typealias:
@@ -4221,12 +4224,13 @@ void Parser::ParsedAccessors::record(Parser &P, AbstractStorageDecl *storage,
 
 
 /// \brief Parse a 'var' or 'let' declaration, doing no token skipping on error.
-ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
-                                  DeclAttributes &Attributes,
-                                  SmallVectorImpl<Decl *> &Decls,
-                                  SourceLoc StaticLoc,
-                                  StaticSpellingKind StaticSpelling,
-                                  SourceLoc TryLoc) {
+ParserResult<PatternBindingDecl>
+Parser::parseDeclVar(ParseDeclOptions Flags,
+                     DeclAttributes &Attributes,
+                     SmallVectorImpl<Decl *> &Decls,
+                     SourceLoc StaticLoc,
+                     StaticSpellingKind StaticSpelling,
+                     SourceLoc TryLoc) {
   assert(StaticLoc.isInvalid() || StaticSpelling != StaticSpellingKind::None);
 
   if (StaticLoc.isValid()) {
@@ -4266,19 +4270,22 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
   // In var/let decl with multiple patterns, accumulate them all in this list
   // so we can build our singular PatternBindingDecl at the end.
   SmallVector<PatternBindingEntry, 4> PBDEntries;
+  auto BaseContext = CurDeclContext;
 
   // No matter what error path we take, make sure the
   // PatternBindingDecl/TopLevel code block are added.
-  SWIFT_DEFER {
+  auto makeResult =
+    [&](ParserStatus Status) -> ParserResult<PatternBindingDecl> {
+
     // If we didn't parse any patterns, don't create the pattern binding decl.
     if (PBDEntries.empty())
-      return;
+      return Status;
 
     // Now that we've parsed all of our patterns, initializers and accessors, we
     // can finally create our PatternBindingDecl to represent the
     // pattern/initializer pairs.
     auto PBD = PatternBindingDecl::create(Context, StaticLoc, StaticSpelling,
-                                          VarLoc, PBDEntries, CurDeclContext);
+                                          VarLoc, PBDEntries, BaseContext);
 
     // Wire up any initializer contexts we needed.
     for (unsigned i : indices(PBDEntries)) {
@@ -4295,13 +4302,16 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
       topLevelDecl->setBody(BraceStmt::create(Context, range.Start,
                                               ASTNode(PBD), range.End, true));
       Decls.insert(Decls.begin()+NumDeclsInResult, topLevelDecl);
-      return;
+      return makeParserResult(Status, PBD);
     }
 
     // Otherwise return the PBD in "Decls" to the caller.  We add it at a
     // specific spot to get it in before any accessors, which SILGen seems to
     // want.
     Decls.insert(Decls.begin()+NumDeclsInResult, PBD);
+
+    // Always return the result for PBD.
+    return makeParserResult(Status, PBD);
   };
 
   do {
@@ -4313,9 +4323,9 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
 
       auto patternRes = parseTypedPattern();
       if (patternRes.hasCodeCompletion())
-        return makeParserCodeCompletionStatus();
+        return makeResult(makeParserCodeCompletionStatus());
       if (patternRes.isNull())
-        return makeParserError();
+        return makeResult(makeParserError());
 
       pattern = patternRes.get();
     }
@@ -4404,12 +4414,13 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
       if (init.hasCodeCompletion() && isCodeCompletionFirstPass()) {
 
         // Register the end of the init as the end of the delayed parsing.
-        DelayedDeclEnd = init.getPtrOrNull() ? init.get()->getEndLoc() : SourceLoc();
-        return makeParserCodeCompletionStatus();
+        DelayedDeclEnd
+          = init.getPtrOrNull() ? init.get()->getEndLoc() : SourceLoc();
+        return makeResult(makeParserCodeCompletionStatus());
       }
 
       if (init.isNull())
-        return makeParserError();
+        return makeResult(makeParserError());
     }
 
     // Parse a behavior block if present.
@@ -4420,9 +4431,9 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
       auto type = parseType(diag::expected_behavior_name,
                             /*handle completion*/ true);
       if (type.isParseError())
-        return makeParserError();
+        return makeResult(makeParserError());
       if (type.hasCodeCompletion())
-        return makeParserCodeCompletionStatus();
+        return makeResult(makeParserCodeCompletionStatus());
 
       // Parse a following trailing closure argument.
       // FIXME: Handle generalized parameters.
@@ -4464,9 +4475,9 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
         PBDEntries.back().setInitContext(initContext);
 
         if (closure.isParseError())
-          return makeParserError();
+          return makeResult(makeParserError());
         if (closure.hasCodeCompletion())
-          return makeParserCodeCompletionStatus();
+          return makeResult(makeParserCodeCompletionStatus());
         paramExpr = closure.get();
       }
 
@@ -4546,10 +4557,7 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
     }
   }
 
-  // NOTE: At this point, the DoAtScopeExit object is destroyed and the PBD
-  // is added to the program.
-  
-  return Status;
+  return makeResult(Status);
 }
 
 void Parser::consumeAbstractFunctionBody(AbstractFunctionDecl *AFD,