Project not compiling with gcc-13

[NicolasIriarte]

It seems later versions of GCC requires the -O to FORTIFY this makes the compilation error fail with:

[115/198] Building CXX object _deps/catch2-build/src/CMakeFiles/Catch2.dir/catch2/matchers/catch_matchers_string.cpp.o
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/matchers/catch_matchers_string.cpp:8:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/matchers/catch_matchers_string.hpp:11:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/matchers/catch_matchers.hpp:11:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/matchers/internal/catch_matchers_impl.hpp:11:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/internal/catch_test_macro_impl.hpp:12:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/internal/catch_assertion_handler.hpp:11:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/catch_assertion_info.hpp:12:
In file included from /home/user/.cache/CPM/catch2/8336fa0dd617945aa607363db497172b01dc4bf1/src/catch2/../catch2/internal/catch_source_line_info.hpp:11:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.1.1/../../../../include/c++/13.1.1/cstddef:49:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.1.1/../../../../include/c++/13.1.1/x86_64-pc-linux-gnu/bits/c++config.h:679:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.1.1/../../../../include/c++/13.1.1/x86_64-pc-linux-gnu/bits/os_defines.h:39:
/usr/include/features.h:413:4: warning: _FORTIFY_SOURCE requires compiling with optimization (-O) [-W#warnings]
#  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
   ^
1 warning generated.

For all sources files, and as -Werror is enabled the whole compilation fails for GCC and CLANG.

I inspected the problematic file /usr/include/features.h:413:4 and here is the content:

#if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0
# if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0
#  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
# elif !__GNUC_PREREQ (4, 1)
#  warning _FORTIFY_SOURCE requires GCC 4.1 or later
# elif _FORTIFY_SOURCE > 2 && (__glibc_clang_prereq (9, 0)		      \
			       || __GNUC_PREREQ (12, 0))

#  if _FORTIFY_SOURCE > 3
#   warning _FORTIFY_SOURCE > 3 is treated like 3 on this platform
#  endif
#  define __USE_FORTIFY_LEVEL 3
# elif _FORTIFY_SOURCE > 1
#  if _FORTIFY_SOURCE > 2
#   warning _FORTIFY_SOURCE > 2 is treated like 2 on this platform
#  endif
#  define __USE_FORTIFY_LEVEL 2
# else
#  define __USE_FORTIFY_LEVEL 1
# endif
#endif
#ifndef __USE_FORTIFY_LEVEL
# define __USE_FORTIFY_LEVEL 0
#endif

It seems it only wants to use FORTIFY for __OPTIMIZE__ > 0.

---

For the meantime, do you recommend disabling FORTIFY or downgrading GCC?

Thanks for your time and this great repository.

EDIT 1:

• Platform: ArchLinux
• GCC: 13.1.1 20230429