clang-format: Fix segfault in 'incomplete' macros.

The code leading to a segfault was:
  #pragma omp threadprivate(y)), // long comment leading to a line break

This fixes llvm.org/PR16513.

llvm-svn: 189460

2 files changed, 7 insertions, 3 deletions

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 199fc022048..798e4f3aecd 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -536,9 +536,10 @@ unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
 
   // If we encounter a closing ), ], } or >, we can remove a level from our
   // stacks.
-  if (Current.isOneOf(tok::r_paren, tok::r_square) ||
-      (Current.is(tok::r_brace) && State.NextToken != Line.First) ||
-      State.NextToken->Type == TT_TemplateCloser) {
+  if (State.Stack.size() > 1 &&
+      (Current.isOneOf(tok::r_paren, tok::r_square) ||
+       (Current.is(tok::r_brace) && State.NextToken != Line.First) ||
+       State.NextToken->Type == TT_TemplateCloser)) {
     State.Stack.pop_back();
     --State.ParenLevel;
   }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index d80011ba175..067a259b2ce 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -1942,6 +1942,9 @@ TEST_F(FormatTest, MacroDefinitionsWithIncompleteCode) {
   verifyFormat("#define A template <typename T>");
   verifyFormat("#define STR(x) #x\n"
                "f(STR(this_is_a_string_literal{));");
+  verifyFormat("#pragma omp threadprivate( \\\n"
+               "    y)), // expected-warning",
+               getLLVMStyleWithColumns(28));
 }
 
 TEST_F(FormatTest, MacrosWithoutTrailingSemicolon) {