On Sun, Sep 13, 2026 at 10:08:52PM -0700, Pierrick Bouvier wrote: > On 9/10/26 11:14 AM, Alex Bennée wrote: > > From: Daniel P. Berrangé <[email protected]> > > > > When it finds a cross compiler, tests/tcg/meson.build tries > > building test_cc.c to validate that the compiler works. This > > includes "stdint.h" as a witness for working C library, however, > > that is not a good choice as it can be provided by the toolchain > > alone: > > > > $ rpm -ql gcc-s390x-linux-gnu | grep /stdint.h > > /usr/lib/gcc/s390x-linux-gnu/16/include/stdint.h > > > > As a result, if you install the s390x GCC cross compiler, but > > not any C library, meson decides to use the host compiler instead > > of the container: > > > > cc for aarch64-softmmu : aarch64-linux-gnu-gcc (from > > 'debian-all-test-cross' container) > > cc for loongarch64-softmmu : loongarch64-unknown-linux-gnu-gcc > > (from 'debian-loongarch-cross' container) > > cc for riscv64-softmmu : riscv64-linux-gnu-gcc (from > > 'debian-all-test-cross' container) > > cc for s390x-softmmu : s390x-linux-gnu-gcc > > cc for x86_64-softmmu : x86_64-linux-gnu-gcc (from > > 'debian-amd64-cross' container) > > > > Eventually this results in failure to run 'make check': > > > > [33/40] Generating tests/tcg/s390x-softmmu-hello with a custom command > > FAILED: [code=1] tests/tcg/s390x-softmmu-hello.test > > /usr/bin/s390x-linux-gnu-gcc > > /home/berrange/src/virt/qemu/tests/tcg/multiarch/system/hello.c -o > > tests/tcg/s390x-softmmu-hello.test -static -MMD -MF > > tests/tcg/s390x-softmmu-hello.d -Wall -Werror -O0 -g -fno-strict-aliasing > > -nostdlib -ffreestanding -Wa,--noexecstack -I > > /home/berrange/src/virt/qemu/tests/tcg/s390x/system/../../minilib > > /home/berrange/src/virt/qemu/tests/tcg/s390x/system/../../minilib/printf.c > > -I /home/berrange/src/virt/qemu/include/hw/s390x/ipl -march=z13 > > ../tests/tcg/s390x/system/../head64.S ../tests/tcg/s390x/system/../console.c > > In file included from ../tests/tcg/s390x/system/../console.c:8: > > ../tests/tcg/s390x/system/../../../../pc-bios/s390-ccw/sclp.c:11:10: fatal > > error: string.h: No such file or directory > > 11 | #include <string.h> > > | ^~~~~~~~~~ > > compilation terminated. > > > > Adding more include files to the test program ensures the > > meson probe makes a better decision. > > > > Fixes: e5d084d622b1 (tests/tcg/meson.build: check host cross cc is working) > > Signed-off-by: Daniel P. Berrangé <[email protected]> > > Message-ID: <[email protected]> > > Signed-off-by: Alex Bennée <[email protected]> > > --- > > tests/tcg/test_cc.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/tests/tcg/test_cc.c b/tests/tcg/test_cc.c > > index d3614a01fe6..fafee055b40 100644 > > --- a/tests/tcg/test_cc.c > > +++ b/tests/tcg/test_cc.c > > @@ -1,7 +1,11 @@ > > /* SPDX-License-Identifier: GPL-2.0-or-later */ > > -/* Include a standard header to make sure cross compiler provides them */ > > +/* Use some standard headers to ensure the cross compiler provides them */ > > #include <stdint.h> > > +#include <string.h> > > +#include <stdbool.h> > > +#include <stddef.h> > > +#include <stdio.h> > > int main(void) > > { > > Ideally, we should do separate tests for system vs user tests. > System ones are always compiled with -ffreestanding, while user ones should > provide a C library. > > From this standard: > > https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2338r3.html > ``` > A freestanding C implementation is required to provide the entirety of the > following headers: > > <float.h> > <iso646.h> > <limits.h> > <stdalign.h> > <stdarg.h> > <stdbool.h> > <stddef.h> > <stdint.h> > <stdnoreturn.h> > Most of <string.h> is required (strdup, strndup, strcoll, strxfrm, and > strerror are excluded). This includes strtok, which requires global data. > ``` > > Maybe for now we can just remove stdio.h from current patch, as it's not > supposed to be provided in a freestanding environment.
A huge number of files under tests/tcg/ have a #include <stdio.h> currently. In the example build failure in the commit message, we have tests/tcg/s390x/system/../console.c which does #include "../../../pc-bios/s390-ccw/sclp.c" and sclp.c has #include "s390-ccw.h" and that header has: #include <stdbool.h> #include <stddef.h> #include <stdint.h> #include <stdio.h> hence the 4 headers I added to the meson check. So AFAICT, our code is expecting stdio.h to be provided in a -ffreestanding build. Have we got a more fundamental mistake wrt our use of -ffreestanding, such that it is relying on unintended functionality ? With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|
