https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66323
Bug ID: 66323
Summary: runtime error with zero sized std::array using begin
and end methods
Product: gcc
Version: 5.1.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: tnozicka at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
Target Milestone: ---
Hi, there is a bug either in undefined behaviour sanitizer or STL. Following
code should be valid according to N3797 draft saying:
1. array shall provide support for the special case N == 0.
2. In the case that N == 0, begin() == end() == unique value.
But compiling and running following code results in sanitizer error:
/opt/szn/include/c++/5.1/array:222:32: runtime error: reference binding to null
pointer of type 'int'
Compiled and run with gcc 5.1 as:
/opt/szn/bin/g++ -std=c++14 -Wall -Wextra -fsanitize=undefined
-Wl,-rpath=/opt/szn/lib/gcc/x86_64-linux-gnu/current -o program main.cpp &&
./program
// === TEST ===
#include <array>
int main()
{
std::array<int, 0> array{};
array.begin();
array.end();
return 0;
}
// === END OF TEST ===
Compiler info: $ /szn/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/opt/szn/bin/g++
COLLECT_LTO_WRAPPER=/opt/szn/lib/gcc/x86_64-linux-gnu/5.1.0/lto-wrapper
Target: x86_64-linux-gnu
Configured with: /home/tnozicka/generic/gcc/gcc-5.1.0/configure
--prefix=/opt/szn --program-suffix=-5.1 --enable-languages=c++
--disable-multilib --with-default-libstdcxx-abi=c++98 --enable-shared
--enable-threads=posix --enable-checking=release --enable-__cxa_atexit
--enable-gnu-unique-object --enable-linker-build-id
--with-linker-hash-style=gnu --enable-plugin --with-tune=generic
--enable-libstdcxx-time=yes --enable-libstdcxx-debug
--enable-version-specific-runtime-libs --enable-objc-gc --enable-clocale=gnu
--disable-install-libiberty --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu --libdir=/opt/szn/lib --libexecdir=/opt/szn/lib
--infodir=/opt/szn/share/info-gcc-5.1 --localedir=/opt/szn/share/locale-gcc-5.1
--mandir=/opt/szn/share/man-gcc-5.1
--with-gxx-include-dir=/opt/szn/include/c++/5.1
Thread model: posix
gcc version 5.1.0 (GCC)
