[CodeComplete] Fix completion at the end of keywords

Summary:
Make completion behave consistently no matter if it is run at the
start, in the middle or at the end of an identifier that happens to
be a keyword or a macro name. Since completion is often ran on
incomplete identifiers, they may turn into keywords by accident.

For example, we should produce same results for all of these
completion points:

    // ^ is completion point.
    ^class
    cla^ss
    class^

Previously clang produced different results for the last case (as if
the completion point was after a space: `class ^`).

This change also updates some offsets in tests that (unintentionally?)
relied on the old behavior.

Reviewers: sammccall, bkramer, arphaman, aaron.ballman

Reviewed By: sammccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D45887

llvm-svn: 330717

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/test/CodeCompletion/end-of-ident.cpp b/clang/test/CodeCompletion/end-of-ident.cpp
new file mode 100644
index 00000000000..f1d3700ce28
--- /dev/null
+++ b/clang/test/CodeCompletion/end-of-ident.cpp
@@ -0,0 +1,20 @@
+class classifier {};
+// We should get all three completions when the cursor is at the beginning,
+// middle, or end.
+class cls
+// ^class cls
+// RUN: %clang_cc1 -code-completion-at=%s:4:1 %s | FileCheck --check-prefix=CHECK-CLS %s
+// cl^ass cls
+// RUN: %clang_cc1 -code-completion-at=%s:4:3 %s | FileCheck --check-prefix=CHECK-CLS %s
+// class^ cls
+// RUN: %clang_cc1 -code-completion-at=%s:4:6 %s | FileCheck --check-prefix=CHECK-CLS %s
+
+// CHECK-CLS: COMPLETION: class{{$}}
+// CHECK-CLS: COMPLETION: classifier : classifier
+
+// class ^cls
+// RUN: %clang_cc1 -code-completion-at=%s:4:7 %s | FileCheck --check-prefix=CHECK-NO-CLS %s
+// class c^ls
+// RUN: %clang_cc1 -code-completion-at=%s:4:8 %s | FileCheck --check-prefix=CHECK-NO-CLS %s
+// CHECK-NO-CLS-NOT: COMPLETION: class{{$}}
+// CHECK-NO-CLS: COMPLETION: classifier : classifier