[PATCH] D20451: [Parser] Fix look ahead after EOF while parsing objc message and lambdas

[Bruno Cardoso Lopes via cfe-commits]

bruno created this revision.
bruno added reviewers: doug.gregor, rsmith.
bruno added a subscriber: cfe-commits.

If a closing ')' isn't found for a macro instantiation inside a '[',
the next token is EOF, this leads to crashes if we try to look ahead of
that. This could be triggered whenever trying to parse lambdas or objs
message expressions.

http://reviews.llvm.org/D20451

Files:
  lib/Parse/ParseExprCXX.cpp
  test/Parser/objcxx11-messaging-and-lambda.mm

Index: test/Parser/objcxx11-messaging-and-lambda.mm
===================================================================
--- /dev/null
+++ test/Parser/objcxx11-messaging-and-lambda.mm
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+
+#define OBJCLASS(name) // expected-note {{macro 'OBJCLASS' defined here}}
+
+class NSMutableData;
+
+NSMutableData *test() { // // expected-note {{to match this '{'}}
+  NSMutableData *data = [[[OBJCLASS(NSMutableDataOBJCLASS( alloc] init] autorelease]; // expected-error {{unterminated function-like macro invocation}} \
+  // expected-error {{expected ';' at end of declaration}}
+  return data;
+} // expected-error {{expected expression}} expected-error {{expected '}'}}
Index: lib/Parse/ParseExprCXX.cpp
===================================================================
--- lib/Parse/ParseExprCXX.cpp
+++ lib/Parse/ParseExprCXX.cpp
@@ -739,8 +739,11 @@
          && Tok.is(tok::l_square)
          && "Not at the start of a possible lambda expression.");
 
-  const Token Next = NextToken(), After = GetLookAheadToken(2);
+  const Token Next = NextToken();
+  if (Next.is(tok::eof)) // Nothing else to lookup here...
+    return ExprEmpty();
 
+  const Token After = GetLookAheadToken(2);
   // If lookahead indicates this is a lambda...
   if (Next.is(tok::r_square) ||     // []
       Next.is(tok::equal) ||        // [=


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