Hi Joshua,
On Fri, Jul 12, 2024 at 12:38:59PM +0000, Joshua Lant wrote:
> Adding this configure option fixes compilation errors which occur when
> building with musl-libc. These are known issues with musl that cause structure
> redefinition errors in headers between linux/if_ether.h and
> netinet/ether.h.
>
> Signed-off-by: Joshua Lant joshualant@xxxxxxxxx
> ---
> INSTALL | 7 +++++++
> configure.ac | 10 +++++++++-
> 2 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/INSTALL b/INSTALL
> index d62b428c..8095b0bb 100644
> --- a/INSTALL
> +++ b/INSTALL
> @@ -63,6 +63,13 @@ Configuring and compiling
> optionally specify a search path to include anyway. This is
> probably only useful for development.
>
> +--enable-musl-build
> +
> + When compiling against musl-libc, you may encounter issues with
> + redefinitions of structures in headers between musl and the kernel.
> + This is a known issue with musl-libc, and setting this option
> + should fix your build.
> +
> If you want to enable debugging, use
>
> ./configure CFLAGS="-ggdb3 -O0"
Niggle: Since at lease gdb 11.2, `info gdb` section
'4.1 Compiling for Debugging' says this:
> | Older versions of the GNU C compiler permitted a variant option '-gg'
> |for debugging information. GDB no longer supports this format; if your
> |GNU C compiler has this option, do not use it.
I suggest `-g3 -gdwarf-4`. This enables gdb commands like `info macro`.
There is also a `-Og` option. Personally, I'm not sure that I like it.
> diff --git a/configure.ac b/configure.ac
> index 2293702b..7f54ccd1 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -77,6 +77,9 @@ AC_ARG_WITH([xt-lock-name], AS_HELP_STRING([--with-xt-lock-name=PATH],
> AC_ARG_ENABLE([profiling],
> AS_HELP_STRING([--enable-profiling], [build for use of gcov/gprof]),
> [enable_profiling="$enableval"], [enable_profiling="no"])
> +AC_ARG_ENABLE([musl-build],
> + AS_HELP_STRING([--enable-musl-build], [Set this option if you encounter compilation errors when building with musl-libc]),
> + [enable_musl_build="$enableval"], [enable_musl_build="no"])
>
> AC_MSG_CHECKING([whether $LD knows -Wl,--no-undefined])
> saved_LDFLAGS="$LDFLAGS";
> @@ -206,6 +209,10 @@ if test "x$enable_profiling" = "xyes"; then
> regular_LDFLAGS+=" -lgcov --coverage"
> fi
>
> +if test "x$enable_musl_build" = "xyes"; then
> + regular_CFLAGS+=" -D__UAPI_DEF_ETHHDR=0"
> +fi
> +
> define([EXPAND_VARIABLE],
> [$2=[$]$1
> if test $prefix = 'NONE'; then
> @@ -277,7 +284,8 @@ Build parameters:
> Installation prefix (--prefix): ${prefix}
> Xtables extension directory: ${e_xtlibdir}
> Pkg-config directory: ${e_pkgconfigdir}
> - Xtables lock file: ${xt_lock_name}"
> + Xtables lock file: ${xt_lock_name}
> + Build against musl-libc: ${enable_musl_build}"
>
> if [[ -n "$ksourcedir" ]]; then
> echo " Kernel source directory: ${ksourcedir}"
> --
> 2.25.1
>
>
Cheers ... Duncan.
