Merge pull request #5251 from rintaro/parse-protocol-any

[Parse] Fix parsing "protocol<Any>"

Author: rintaro

lib/Parse/ParseType.cpp

@@ -410,30 +410,20 @@ ParserResult<TypeRepr> Parser::parseTypeIdentifierOrTypeComposition() {
     SourceLoc ProtocolLoc = consumeToken(tok::kw_protocol);
     SourceLoc LAngleLoc = consumeStartingLess();
 
-    // Check for empty protocol composition.
-    if (startsWithGreater(Tok)) {
-      SourceLoc RAngleLoc = consumeStartingGreater();
-      auto AnyRange = SourceRange(ProtocolLoc, RAngleLoc);
-      
-      // Warn that 'protocol<>' is deprecated and offer to
-      // replace with the 'Any' keyword
-      diagnose(LAngleLoc, diag::deprecated_any_composition)
-        .fixItReplace(AnyRange, "Any");
-      
-      return makeParserResult(
-        ProtocolCompositionTypeRepr::createEmptyComposition(Context, ProtocolLoc));
-    }
-    
     // Parse the type-composition-list.
     ParserStatus Status;
     SmallVector<IdentTypeRepr *, 4> Protocols;
-    do {
-      // Parse the type-identifier.
-      ParserResult<TypeRepr> Protocol = parseTypeIdentifier();
-      Status |= Protocol;
-      if (auto *ident = dyn_cast_or_null<IdentTypeRepr>(Protocol.getPtrOrNull()))
-        Protocols.push_back(ident);
-    } while (consumeIf(tok::comma));
+    bool IsEmpty = startsWithGreater(Tok);
+    if (!IsEmpty) {
+      do {
+        // Parse the type-identifier.
+        ParserResult<TypeRepr> Protocol = parseTypeIdentifier();
+        Status |= Protocol;
+        if (auto *ident = dyn_cast_or_null<IdentTypeRepr>(
+                                                       Protocol.getPtrOrNull()))
+          Protocols.push_back(ident);
+      } while (consumeIf(tok::comma));
+    }
 
     // Check for the terminating '>'.
     SourceLoc RAngleLoc = PreviousLoc;
@@ -456,33 +446,40 @@ ParserResult<TypeRepr> Parser::parseTypeIdentifierOrTypeComposition() {
     if (Status.isSuccess()) {
       // Only if we have complete protocol<...> construct, diagnose deprecated.
 
-      auto extractText = [&](IdentTypeRepr *Ty) -> StringRef {
-        auto SourceRange = Ty->getSourceRange();
-        return SourceMgr.extractText(
-          Lexer::getCharSourceRangeFromSourceRange(SourceMgr, SourceRange));
-      };
       SmallString<32> replacement;
-      auto Begin = Protocols.begin();
-      replacement += extractText(*Begin);
-      while (++Begin != Protocols.end()) {
-        replacement += " & ";
+      if (Protocols.empty()) {
+        replacement = "Any";
+      } else {
+        auto extractText = [&](IdentTypeRepr *Ty) -> StringRef {
+          auto SourceRange = Ty->getSourceRange();
+          return SourceMgr.extractText(
+            Lexer::getCharSourceRangeFromSourceRange(SourceMgr, SourceRange));
+        };
+        auto Begin = Protocols.begin();
         replacement += extractText(*Begin);
+        while (++Begin != Protocols.end()) {
+          replacement += " & ";
+          replacement += extractText(*Begin);
+        }
       }
 
       // Copy trailing content after '>' to the replacement string.
       // FIXME: lexer should smartly separate '>' and trailing contents like '?'.
       StringRef TrailingContent = L->getTokenAt(RAngleLoc).getRange().str().
         substr(1);
       if (!TrailingContent.empty()) {
-        replacement.insert(replacement.begin(), '(');
-        replacement += ")";
+        if (Protocols.size() > 1) {
+          replacement.insert(replacement.begin(), '(');
+          replacement += ")";
+        }
         replacement += TrailingContent;
       }
 
       // Replace 'protocol<T1, T2>' with 'T1 & T2'
       diagnose(ProtocolLoc,
-        Protocols.size() > 1 ? diag::deprecated_protocol_composition
-                             : diag::deprecated_protocol_composition_single)
+        IsEmpty              ? diag::deprecated_any_composition :
+        Protocols.size() > 1 ? diag::deprecated_protocol_composition :
+                               diag::deprecated_protocol_composition_single)
         .highlight(composition->getSourceRange())
         .fixItReplace(composition->getSourceRange(), replacement);
     }

test/FixCode/fixits-apply.swift.result

@@ -308,4 +308,4 @@ func testBoolValue(a : BoolFoo) {
 protocol P1 {}
 protocol P2 {}
 var a : (P1 & P2)?
-var a2 : (P1)= 17 as! P1
+var a2 : P1= 17 as! P1

test/type/protocol_composition.swift

@@ -123,13 +123,17 @@ func testConversion() {
 }
 
 // Test the parser's splitting of >= into > and =.
-var x : protocol<P5>= 17 // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{9-22=(P5)=}}
+var x : protocol<P5>= 17 // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{9-22=P5=}}
+var y : protocol<P5, P7>= 17 // expected-warning {{'protocol<...>' composition syntax is deprecated; join the protocols using '&'}} {{9-26=(P5 & P7)=}}
 
-typealias A = protocol<> // expected-warning {{'protocol<>' syntax is deprecated; use 'Any' instead}} {{15-25=Any}}
+typealias A1 = protocol<> // expected-warning {{'protocol<>' syntax is deprecated; use 'Any' instead}} {{16-26=Any}}
+typealias A2 = protocol<>? // expected-warning {{'protocol<>' syntax is deprecated; use 'Any' instead}} {{16-27=Any?}}
 typealias B1 = protocol<P1,P2> // expected-warning {{'protocol<...>' composition syntax is deprecated; join the protocols using '&'}} {{16-31=P1 & P2}}
 typealias B2 = protocol<P1, P2> // expected-warning {{'protocol<...>' composition syntax is deprecated; join the protocols using '&'}} {{16-32=P1 & P2}}
 typealias B3 = protocol<P1 ,P2> // expected-warning {{'protocol<...>' composition syntax is deprecated; join the protocols using '&'}} {{16-32=P1 & P2}}
 typealias B4 = protocol<P1 , P2> // expected-warning {{'protocol<...>' composition syntax is deprecated; join the protocols using '&'}} {{16-33=P1 & P2}}
 typealias C1 = protocol<Any, P1> // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{16-33=P1}}
 typealias C2 = protocol<P1, Any> // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{16-33=P1}}
 typealias D = protocol<P1> // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{15-27=P1}}
+typealias E = protocol<Any> // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{15-28=Any}}
+typealias F = protocol<Any, Any> // expected-warning {{'protocol<...>' composition syntax is deprecated and not needed here}} {{15-33=Any}}