[SemaCXX] Fix ICE for unexpanded parameter pack
Summary:
The documentation for RecursiveASTVisitor::TraverseDecl states that the
Decl being traversed may be null. In fact, this is the case when a
CXXCatchStmt with no exception decl is traversed. Because the visitor
for diagnosing unexpanded parameter packs does not check for null, it
ends up crashing when it attempts to call the Decl::isParameterPack
method on a null Decl pointer.
Add a null check to prevent an ICE, and a test case that would crash
otherwise. Also, because the test requires C++ exceptions and C++14,
change the test parameters for the entire test file. (Alternatively, I
thought about adding a new test file, but went with this approach for my
own convenience.)
Co-authored-by: Andreas Molzer <andreas.molzer@gmx.de>
Co-authored-by: Mara Bos <m-ou.se@m-ou.se>
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D56271
llvm-svn: 350501
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index 3338cec..0e7fc20 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -164,7 +164,7 @@
// A function parameter pack is a pack expansion, so cannot contain
// an unexpanded parameter pack. Likewise for a template parameter
// pack that contains any references to other packs.
- if (D->isParameterPack())
+ if (D && D->isParameterPack())
return true;
return inherited::TraverseDecl(D);