compilation failure for global/src/sketch.c #374
Description
The default gcc with the newly released opensuse 16.0 has been configured to have -Werror=return-type by default:
# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/15/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-suse-linux
Configured with: ../configure CFLAGS=' -O2 -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g' CXXFLAGS=' -O2 -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g' XCFLAGS=' -O2 -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g' TCFLAGS=' -O2 -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g' GDCFLAGS=' -O2 -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -g' --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64 --enable-languages=c,c++,objc,fortran,obj-c++,ada,go,d,jit,m2 --enable-host-pie --enable-offload-targets=nvptx-none,amdgcn-amdhsa, --enable-offload-defaulted --without-cuda-driver --enable-host-shared --enable-checking=release --disable-werror --with-gxx-include-dir=/usr/include/c++/15 --with-libstdcxx-zoneinfo=/usr/share/zoneinfo --enable-ssp --disable-libssp --disable-libvtv --enable-cet=auto --disable-libcc1 --disable-plugin --with-bugurl=https://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --with-slibdir=/lib64 --with-system-zlib --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-libphobos --enable-version-specific-runtime-libs --with-gcc-major-version-only --enable-linker-build-id --enable-linux-futex --enable-gnu-indirect-function --program-suffix=-15 --without-system-libunwind --enable-multilib --with-arch-32=x86-64-v2 --with-arch=x86-64-v2 --with-tune=generic --with-build-config=bootstrap-lto-lean --enable-link-serialization --build=x86_64-suse-linux --host=x86_64-suse-linux
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.1.1 20250714 (SUSE Linux)
This results in:
libtool: compile: mpicc -DHAVE_CONFIG_H -I. -Ima -I./ma -I./LinAlg/lapack+blas -Iglobal/src -I./global/src -I./global/testing -I./pario/dra -I./pario/eaf -I./pario/elio -I./pario/sf -Igaf2c -I./gaf2c -I./tcgmsg -I./tcgmsg/tcgmsg-mpi -I./comex/src-armci -fno-aggressive-loop-optimizations -fno-tree-slp-vectorize -std=gnu17 -MT global/src/sketch.lo -MD -MP -MF global/src/.deps/sketch.Tpo -c global/src/sketch.c -o global/src/sketch.o
global/src/sketch.c: In function 'pnga_sprs_array_count_sketch':
global/src/sketch.c:102:18: warning: unused variable 'kcnt' [-Wunused-variable]
102 | Integer k, kk, kcnt;
| ^~~~
global/src/sketch.c:88:21: warning: unused variable 'jj' [-Wunused-variable]
88 | Integer i, ii, j, jj, n, hdl, g_a;
| ^~
global/src/sketch.c:88:18: warning: unused variable 'j' [-Wunused-variable]
88 | Integer i, ii, j, jj, n, hdl, g_a;
| ^
global/src/sketch.c:88:14: warning: unused variable 'ii' [-Wunused-variable]
88 | Integer i, ii, j, jj, n, hdl, g_a;
| ^~
global/src/sketch.c: In function 'pnga_sprs_array_num_nonzeros':
global/src/sketch.c:441:1: error: control reaches end of non-void function [-Werror=return-type]
441 | }
| ^
cc1: some warnings being treated as error
For now one can work around this by explicitly disabling this at configure time:
./configure CFLAGS='-Wno-error=return-type' ...