Error building gcc master: gcc/opts.cc: -Werror=format-truncation

[Alejandro Colomar]

Hi,

I'm getting this error while building GCC from the master branch:

alx@debian:~/src/gnu/gcc/.tmp$ make 'BOOT_CFLAGS=-march=native' bootstrap
[...]
/home/alx/src/gnu/gcc/.tmp/./prev-gcc/xg++ -B/home/alx/src/gnu/gcc/.tmp/./prev-gcc/ -B/opt/gnu/gcc/alx/Wusi/1/x86_64-pc-linux-gnu/bin/ -nostdinc++ -B/home/alx/src/gnu/gcc/.tmp/prev-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs -B/home/alx/src/gnu/gcc/.tmp/prev-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs  -I/home/alx/src/gnu/gcc/.tmp/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu  -I/home/alx/src/gnu/gcc/.tmp/prev-x86_64-pc-linux-gnu/libstdc++-v3/include  -I/home/alx/src/gnu/gcc/libstdc++-v3/libsupc++ -L/home/alx/src/gnu/gcc/.tmp/prev-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs -L/home/alx/src/gnu/gcc/.tmp/prev-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs  -fno-PIE -c   -march=native -fno-checking -gtoggle -DIN_GCC     -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -Wconditionally-supported -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common  -DHAVE_CONFIG_H -I. -I. -I../../gcc -I../../gcc/. -I../../gcc/../include  -I../../gcc/../libcpp/include -I../../gcc/../libcody  -I../../gcc/../libdecnumber -I../../gcc/../libdecnumber/bid -I../libdecnumber -I../../gcc/../libbacktrace   -o opts.o -MT opts.o -MMD -MP -MF ./.deps/opts.TPo ../../gcc/opts.cc
../../gcc/opts.cc: In function ‘void print_filtered_help(unsigned int, unsigned int, unsigned int, unsigned int, gcc_options*, unsigned int)’:
../../gcc/opts.cc:1685:26: error: ‘  ’ directive output may be truncated writing 2 bytes into a region of size between 1 and 256 [-Werror=format-truncation=]
 1685 |                       "%s  %s", help, _(use_diagnosed_msg));
      |                          ^~
../../gcc/opts.cc:1684:22: note: ‘snprintf’ output 3 or more bytes (assuming 258) into a destination of size 256
 1684 |             snprintf (new_help, sizeof new_help,
      |             ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
 1685 |                       "%s  %s", help, _(use_diagnosed_msg));
      |                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
make[3]: *** [Makefile:1152: opts.o] Error 1


My system is Debian Sid, and GCC 12.2.0:
$ gcc --version
gcc (Debian 12.2.0-14) 12.2.0
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


Is it some known issue?  I was trying to test a patch I'm developing,
but I can't even build from master.

Thanks,

Alex


-- 
<http://www.alejandro-colomar.es/>
GPG key fingerprint: A9348594CE31283A826FBDD8D57633D441E25BB5
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