fix <rdar://problem/20457938> typed pattern is not allowed on if/let condition

Swift SVN r27110

include/swift/Parse/Parser.h

@@ -1021,7 +1021,8 @@ public:
   parsePatternTupleElement();
   ParserResult<Pattern> parsePatternTuple();
   
-  ParserResult<Pattern> parseTypedMatchingPattern();
+  ParserResult<Pattern>
+  parseOptionalPatternTypeAnnotation(ParserResult<Pattern> P);
   ParserResult<Pattern> parseMatchingPattern(bool isExprBasic);
   ParserResult<Pattern> parseMatchingPatternAsLetOrVar(bool isLet,
                                                        SourceLoc VarLoc,

lib/Parse/ParseDecl.cpp

@@ -3452,7 +3452,8 @@ ParserStatus Parser::parseDeclVar(ParseDeclOptions Flags,
       llvm::SaveAndRestore<decltype(InVarOrLetPattern)>
       T(InVarOrLetPattern, isLet ? IVOLP_InLet : IVOLP_InVar);
 
-      auto patternRes = parseTypedMatchingPattern();
+      auto patternRes = parseMatchingPattern(/*isExprBasic*/true);
+      patternRes = parseOptionalPatternTypeAnnotation(patternRes);
 
       if (patternRes.hasCodeCompletion())
         return makeParserCodeCompletionStatus();

lib/Parse/ParsePattern.cpp

@@ -941,17 +941,22 @@ ParserResult<Pattern> Parser::parsePatternTuple() {
                                           EllipsisLoc.isValid(), EllipsisLoc));
 }
 
-/// Parse a pattern with an optional type annotation.
+/// Parse an optional type annotation on a pattern.
 ///
-///  typed-pattern ::= mattching-pattern (':' type)?
+///  pattern-type-annotation ::= (':' type)?
 ///
-ParserResult<Pattern> Parser::parseTypedMatchingPattern() {
-  auto result = parseMatchingPattern(/*isExprBasic*/true);
+ParserResult<Pattern> Parser::
+parseOptionalPatternTypeAnnotation(ParserResult<Pattern> result) {
 
-  // Now parse an optional type annotation.
-  if (consumeIf(tok::colon)) {
+  // Parse an optional type annotation.
+  if (!consumeIf(tok::colon))
+    return result;
+
+  Pattern *P;
   if (result.isNull())  // Recover by creating AnyPattern.
-      result = makeParserErrorResult(new (Context) AnyPattern(PreviousLoc));
+    P = new (Context) AnyPattern(Tok.getLoc());
+  else
+    P = result.get();
 
   ParserResult<TypeRepr> Ty = parseType();
   if (Ty.hasCodeCompletion())
@@ -959,11 +964,7 @@ ParserResult<Pattern> Parser::parseTypedMatchingPattern() {
   if (Ty.isNull())
     Ty = makeParserResult(new (Context) ErrorTypeRepr(PreviousLoc));
 
-    result = makeParserResult(result,
-                            new (Context) TypedPattern(result.get(), Ty.get()));
-  }
-  
-  return result;
+  return makeParserResult(new (Context) TypedPattern(P, Ty.get()));
 }
 
 

lib/Parse/ParseStmt.cpp

@@ -850,9 +850,11 @@ ParserStatus Parser::parseStmtCondition(StmtCondition &Condition,
       //
       if (Tok.is(tok::identifier) && peekToken().is(tok::colon))
         Pattern = parseSwift1IfLetPattern(IsLet, VarLoc);
-      else
+      else {
         Pattern = parseMatchingPatternAsLetOrVar(IsLet, VarLoc,
                                                  /*isExprBasic*/ true);
+        Pattern = parseOptionalPatternTypeAnnotation(Pattern);
+      }
       Status |= Pattern;
       
       if (Pattern.isNull() || Pattern.hasCodeCompletion())

test/stmt/if_while_var.swift

@@ -59,6 +59,10 @@ if 1 != 2, let x? = opt, y? = opt where x != y,
    let a? = opt, var b? = opt {
 }
 
+// <rdar://problem/20457938> typed pattern is not allowed on if/let condition
+if 1 != 2, let x? : Int? = opt {}
+
+
 // Test error recovery.
 // <rdar://problem/19939746> Improve error recovery for malformed if statements
 if 1 != 2, {  // expected-error {{expected 'let' or 'var' in conditional}}