[fuzz] Assertion `Val && "isa<> used on a null pointer"' failed.

[llvmbot]

Bugzilla Link	21852
Resolution	FIXED
Resolved on	Oct 21, 2016 17:45
Version	trunk
OS	Linux
Blocks	#23431
Attachments	test case
Reporter	LLVM Bugzilla Contributor
CC	@majnemer,@rnk

Extended Description

Fuzzing discovered that the attached test case, when given as input to

clang -fno-crash-diagnostics -std=c++11 -xc++ -c -emit-llvm

causes this assertion failure:

clang-3.6: include/llvm/Support/Casting.h:95: static bool llvm::isa_impl_cl<clang::ExprWithCleanups, const clang::Expr *>::doit(const From *) [To = clang::ExprWithCleanups, From = const clang::Expr *]: Assertion `Val && "isa<> used on a null pointer"' failed.

[majnemer]

reduced:
void g(int=, int);
void f() { g(0); }

[rnk]

Both tests don't crash.

[kcc]

mentioned in issue #23431