[Format/ObjC] Fix [foo bar]->baz formatting as lambda arrow

Summary:
Currently, `UnwrappedLineParser` thinks an arrow token after
an ObjC method expression is a C++ lambda arrow, so it formats:

```
[foo bar]->baz
```

as:

```
[foo bar] -> baz
```

Because `UnwrappedLineParser` runs before `TokenAnnotator`, it can't
know if the arrow token is after an ObjC method expression or not.

This diff makes `TokenAnnotator` remove the TT_LambdaArrow on
the arrow token if it follows an ObjC method expression.

Test Plan: New test added. Ran test with:
  % ninja FormatTests && ./tools/clang/unittests/Format/FormatTests
  Confirmed test failed before diff and passed after diff.

Reviewers: krasimir, djasper, sammccall

Reviewed By: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D57923

llvm-svn: 353531

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/unittests/Format/FormatTestObjC.cpp b/clang/unittests/Format/FormatTestObjC.cpp
index 0d3a5d85bb7..ef725a81a88 100644
--- a/clang/unittests/Format/FormatTestObjC.cpp
+++ b/clang/unittests/Format/FormatTestObjC.cpp
@@ -611,6 +611,7 @@ TEST_F(FormatTestObjC, FormatObjCMethodDeclarations) {
 
 TEST_F(FormatTestObjC, FormatObjCMethodExpr) {
   verifyFormat("[foo bar:baz];");
+  verifyFormat("[foo bar]->baz;");
   verifyFormat("return [foo bar:baz];");
   verifyFormat("return (a)[foo bar:baz];");
   verifyFormat("f([foo bar:baz]);");