From 7dda73a223c2c2bc48ba37f2cc3c1fd7b976c186 Mon Sep 17 00:00:00 2001 From: Brian Gesiak Date: Mon, 7 Jan 2019 03:25:59 +0000 Subject: [PATCH] [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 Co-authored-by: Mara Bos Reviewers: rsmith Reviewed By: rsmith Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D56271 llvm-svn: 350501 --- clang/lib/Sema/SemaTemplateVariadic.cpp | 2 +- clang/test/SemaCXX/alias-template.cpp | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) 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 @@ namespace { // 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); diff --git a/clang/test/SemaCXX/alias-template.cpp b/clang/test/SemaCXX/alias-template.cpp index f2ba04d..0a92b9d 100644 --- a/clang/test/SemaCXX/alias-template.cpp +++ b/clang/test/SemaCXX/alias-template.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -verify -std=c++11 %s +// RUN: %clang_cc1 -verify -std=c++14 -fcxx-exceptions %s namespace RedeclAliasTypedef { template using T = int; @@ -189,3 +189,7 @@ int sfinae_me() { return 0; } // expected-note{{candidate template ignored: subs int g = sfinae_me(); // expected-error{{no matching function for call to 'sfinae_me'}} } + +namespace NullExceptionDecl { +template auto get = []() { try { } catch(...) {}; return I; }; // expected-error{{initializer contains unexpanded parameter pack 'I'}} +} -- 2.7.4