[clang-tidy] TwineLocalCheck: add param # checking

Summary:
The statement **getArg** tries to get the first one without checking, which may cause segmentation fault.

 

Reviewers: chh, bkramer

Reviewed By: bkramer

Subscribers: cfe-commits, xazax.hun

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D33103

llvm-svn: 303001

1 files changed, 4 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/llvm/TwineLocalCheck.cpp b/clang-tools-extra/clang-tidy/llvm/TwineLocalCheck.cpp
index 3fb5f5d9f0a..67c85a6728c 100644
--- a/clang-tools-extra/clang-tidy/llvm/TwineLocalCheck.cpp
+++ b/clang-tools-extra/clang-tidy/llvm/TwineLocalCheck.cpp
@@ -35,8 +35,11 @@ void TwineLocalCheck::check(const MatchFinder::MatchResult &Result) {
     // of the initializer.
     const Expr *C = VD->getInit()->IgnoreImplicit();
 
-    while (isa<CXXConstructExpr>(C))
+    while (isa<CXXConstructExpr>(C)) {
+      if (cast<CXXConstructExpr>(C)->getNumArgs() == 0)
+        break;
       C = cast<CXXConstructExpr>(C)->getArg(0)->IgnoreParenImpCasts();
+    }
 
     SourceRange TypeRange =
         VD->getTypeSourceInfo()->getTypeLoc().getSourceRange();