Fix loop-convert crash.

Summary: loop-convert no longer crashes when calling a member function using a member pointer which is a member of another record.

Reviewers: alexfh, klimek

Subscribers: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D12555

llvm-svn: 246655

2 files changed, 15 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/modernize/LoopConvertUtils.cpp b/clang-tools-extra/clang-tidy/modernize/LoopConvertUtils.cpp
index 732d40bd604..f2e0f552180 100644
--- a/clang-tools-extra/clang-tidy/modernize/LoopConvertUtils.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/LoopConvertUtils.cpp
@@ -370,7 +370,10 @@ static bool isAliasDecl(const Decl *TheDecl, const VarDecl *IndexVar) {
 
   case Stmt::CXXMemberCallExprClass: {
     const auto *MemCall = cast<CXXMemberCallExpr>(Init);
-    if (MemCall->getMethodDecl()->getName() == "at") {
+    // This check is needed because getMethodDecl can return nullptr if the
+    // callee is a member function pointer.
+    if (MemCall->getMethodDecl() &&
+        MemCall->getMethodDecl()->getName() == "at") {
       assert(MemCall->getNumArgs() == 1);
       return isIndexInSubscriptExpr(MemCall->getArg(0), IndexVar);
     }
diff --git a/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp b/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp
index 9d3b211bd77..7f31a5f4ca4 100644
--- a/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp
+++ b/clang-tools-extra/test/clang-tidy/modernize-loop-convert-basic.cpp
@@ -156,6 +156,17 @@ void memberFunctionPointer() {
   // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
   // CHECK-FIXES: for (auto & elem : mfpArr)
   // CHECK-FIXES-NEXT: (v.*elem)();
+
+  struct Foo {
+    int (Val::*f)();
+  } foo[N];
+
+  for (int i = 0; i < N; ++i)
+    int r = (v.*(foo[i].f))();
+  // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto & elem : foo)
+  // CHECK-FIXES-NEXT: int r = (v.*(elem.f))();
+
 }
 
 } // namespace Array