On Sat, Feb 23, 2019 at 01:02:20AM +0000, Jonathan Wakely wrote:
> PR libstdc++/89446
> * include/bits/char_traits.h (__constant_char_array): Check index is
> in range before dereferencing.
> * testsuite/21_strings/basic_string_view/operators/char/89446.cc:
> New test.
>
> Tested x86_64-linux, committed to gcc-8-branch and gcc-7-branch.
And not trunk? The bug is still there, even when it should be usually
ifdefed out because __builtin_is_constexpr_evaluated() should be supported.
> commit b639a9cac6e2532eb852b03df6ac40d34f1dd28c
> Author: Jonathan Wakely <jwak...@redhat.com>
> Date: Fri Feb 22 20:33:16 2019 +0000
>
> PR libstdc++/89446 fix null pointer dereference in char_traits
>
> PR libstdc++/89446
> * include/bits/char_traits.h (__constant_char_array): Check index
> is
> in range before dereferencing.
> * testsuite/21_strings/basic_string_view/operators/char/89446.cc:
> New test.
>
> diff --git a/libstdc++-v3/include/bits/char_traits.h
> b/libstdc++-v3/include/bits/char_traits.h
> index 1945494d7e2..a2a883f3565 100644
> --- a/libstdc++-v3/include/bits/char_traits.h
> +++ b/libstdc++-v3/include/bits/char_traits.h
> @@ -248,7 +248,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __constant_char_array_p(const _CharT* __a, size_t __n)
> {
> size_t __i = 0;
> - while (__builtin_constant_p(__a[__i]) && __i < __n)
> + while (__i < __n && __builtin_constant_p(__a[__i]))
> __i++;
> return __i == __n;
> }
Jakub
