Forgot to tag as RFC.
Cc'ing mjt to have feedback from Debian packaging.
On 5/15/21 8:35 PM, Philippe Mathieu-Daudé wrote:
> When selecting an ARM target on Debian unstable, we get:
>
> Compiling C++ object libcommon.fa.p/disas_libvixl_vixl_utils.cc.o
> FAILED: libcommon.fa.p/disas_libvixl_vixl_utils.cc.o
> c++ -Ilibcommon.fa.p -I. -I.. [...] -o
> libcommon.fa.p/disas_libvixl_vixl_utils.cc.o -c ../disas/libvixl/vixl/utils.cc
> In file included from /home/philmd/qemu/disas/libvixl/vixl/utils.h:30,
> from ../disas/libvixl/vixl/utils.cc:27:
> /usr/include/string.h:36:43: error: missing binary operator before token "("
> 36 | #if defined __cplusplus && (__GNUC_PREREQ (4, 4) \
> | ^
> /usr/include/string.h:53:62: error: missing binary operator before token "("
> 53 | #if defined __USE_MISC || defined __USE_XOPEN || __GLIBC_USE
> (ISOC2X)
> | ^
> /usr/include/string.h:165:21: error: missing binary operator before token
> "("
> 165 | || __GLIBC_USE (LIB_EXT2) || __GLIBC_USE (ISOC2X))
> | ^
> /usr/include/string.h:174:43: error: missing binary operator before token
> "("
> 174 | #if defined __USE_XOPEN2K8 || __GLIBC_USE (LIB_EXT2) || __GLIBC_USE
> (ISOC2X)
> | ^
> /usr/include/string.h:492:19: error: missing binary operator before token
> "("
> 492 | #if __GNUC_PREREQ (3,4)
> | ^
>
> Similarly to commit 875df03b221 ('osdep: protect qemu/osdep.h with
> extern "C"'), guard the <string.h> system header with 'extern "C"'.
>
> Relevant information from the host:
>
> $ lsb_release -d
> Description: Debian GNU/Linux 11 (bullseye)
> $ gcc --version
> gcc (Debian 10.2.1-6) 10.2.1 20210110
> $ dpkg -S /usr/include/string.h
> libc6-dev: /usr/include/string.h
> $ apt-cache show libc6-dev
> Package: libc6-dev
> Version: 2.31-11
>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1914870
> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> ---
> RFC because I've no idea about C++, but this fixes the build for me.
>
> Quick reproducer:
>
> $ ../configure --disable-tools --target-list=aarch64-linux-user
>
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Cc: Daniel P. Berrangé <berra...@redhat.com>
> Cc: Peter Maydell <peter.mayd...@linaro.org>
> Cc: Richard Henderson <richard.hender...@linaro.org>
> Cc: Eric Blake <ebl...@redhat.com>
> Cc: Thomas Huth <th...@redhat.com>
> ---
> disas/libvixl/vixl/utils.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/disas/libvixl/vixl/utils.h b/disas/libvixl/vixl/utils.h
> index 5ab134e240a..fc28d7456c1 100644
> --- a/disas/libvixl/vixl/utils.h
> +++ b/disas/libvixl/vixl/utils.h
> @@ -27,8 +27,10 @@
> #ifndef VIXL_UTILS_H
> #define VIXL_UTILS_H
>
> -#include <string.h>
> #include <cmath>
> +extern "C" {
> +#include <string.h>
> +}
> #include "vixl/globals.h"
> #include "vixl/compiler-intrinsics.h"
>
>
