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 <berrange@redhat.com>
---
 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 d3614a01fe..fafee055b4 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)
 {
-- 
2.55.0

Daniel P. Berrangé <berrange@redhat.com> writes:

> 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

Queued to testing/next, thanks.
<snip>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro