Re: [Valgrind-developers] missing -Wformat warnings

[Paul F. <pj...@wa...>]

On 07/05/2025 18:55, Florian Krohm wrote:
> Greetings.
>
> I noticed that the presence of -fno-builtin suppresses -Wformat warnings.
> First I thought this to be a GCC bug but it is not.

Strange. I don't see any relationship between the two.

> -fno-builtin was added to Makefile.all.am in e8ce3f7abb mentioning 
> explicitly this to be needed for an LLVM workaround. The attached 
> patch moves this option to the COMPILER_IS_CLANG section and fixes the 
> fallout.
>
> AM_CFLAGS_PSO_BASE is not being changed because doing so causes
> memcheck/tests/wcpncpy and drd/tests/sem_open_traced to fail.
>
> Regtested on x86_64-linux-gnu and s390x-ibm-linux-gnu with no failures.
>
> OK ?

No. On openSUSE Leap 15.6 amd64 with GCC 14.2 I get link errors. We 
would need to provide a 'strlen' implementation at least for amd64 Linux.

Here are the errors:

../coregrind/link_tool_exe_linux 0x58000000 gcc-14     -o 
memcheck-amd64-linux  -m64 -O2 -g -Wall -Wmissing-prototypes -Wshadow 
-Wpointer-arith -Wstrict-prototypes -Wmissing-declarations 
-Wno-unused-result -Wcast-align -Wcast-qual -Wwrite-strings -Wempty-body 
-Wformat -Wformat-signedness -Wformat-security -Wignored-qualifiers 
-Wmissing-parameter-type -Wlogical-op -Wenum-conversion 
-Wimplicit-fallthrough=2 -Wold-style-declaration -finline-functions 
-fno-stack-protector -fno-strict-aliasing   -fomit-frame-pointer -O2 
-static -nodefaultlibs -nostartfiles -u _start  -m64 
memcheck_amd64_linux-mc_leakcheck.o 
memcheck_amd64_linux-mc_malloc_wrappers.o memcheck_amd64_linux-mc_main.o 
memcheck_amd64_linux-mc_main_asm.o memcheck_amd64_linux-mc_translate.o 
memcheck_amd64_linux-mc_machine.o memcheck_amd64_linux-mc_errors.o 
../coregrind/libcoregrind-amd64-linux.a ../VEX/libvex-amd64-linux.a 
-lgcc ../coregrind/libgcc-sup-amd64-linux.a
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: 
../coregrind/libcoregrind-amd64-linux.a(libcoregrind_amd64_linux_a-m_libcbase.o): 
in function `vgPlain_strlen':
/home/paulf/scratch/valgrind/coregrind/m_libcbase.c:263:(.text+0xc8e): 
undefined reference to `strlen'
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: 
/home/paulf/scratch/valgrind/coregrind/m_libcbase.c:263:(.text+0x106b): 
undefined reference to `strlen'
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: 
/home/paulf/scratch/valgrind/coregrind/m_libcbase.c:263:(.text+0x10db): 
undefined reference to `strlen'
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: 
/home/paulf/scratch/valgrind/coregrind/m_libcbase.c:263:(.text+0x1175): 
undefined reference to `strlen'
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: 
/home/paulf/scratch/valgrind/coregrind/m_libcbase.c:263:(.text+0x13fd): 
undefined reference to `strlen'
/usr/lib64/gcc/x86_64-suse-linux/14/../../../../x86_64-suse-linux/bin/ld: 
../coregrind/libcoregrind-amd64-linux.a(libcoregrind_amd64_linux_a-m_libcbase.o):/home/paulf/scratch/valgrind/coregrind/m_libcbase.c:263: 
more undefined references to `strlen' follow

A+

Paul