[Buildroot] [PATCH] modem-manager: remove -Werror from CFLAGS

[Peter Korsgaard <peter@korsgaard.com>]

>>>>> "Carlos" == Carlos Santos <casantos@datacom.ind.br> writes:

 > We are aproaching the 2018.05 release and modem-manager is still broken
 > due to warnings like this:

 >   mm-base-manager.c: In function 'handle_set_logging':
 >   mm-base-manager.c:680:15: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
 ctx-> self = g_object_ref (manager);
 >                  ^

 > There is a macro defined in build/libglib2-2.56.1/gobject/gobject.h
 > which leads to the assignment errors:

 >   511 /* Make reference APIs type safe with macros */
 >   512 #define g_object_ref(Obj)      ((__typeof__(Obj)) (g_object_ref) (Obj))

 > The problem can be easily reproduced with this sample code:

 >   $ cat test.c
 >   extern void *g_object_ref(void *);
 >   #define g_object_ref(Obj) ((__typeof__(Obj)) (g_object_ref) (Obj))
 >   extern double *new_double(int *);
 >   double *new_double(int *ip) {
 >     double *dp;
 >     dp = g_object_ref(ip);
 >     return dp;
 >   }

 >   $ gcc -Wall -Werror -c /tmp/test.c -o /tmp/test.o
 >   /tmp/test.c: In function ?new_context?:
 >   /tmp/test.c:19:13: error: assignment from incompatible pointer type [-Werror=incompatible-pointer-types]
 ctx-> self = g_object_ref(om);
 >                ^
 >   cc1: all warnings being treated as errors

 > Fixing the code would require either changing the 120 ofending calls to
 > g_object_ref or a refactoring to make all types assignment compatible.
 > Let's take a simpler approach, disabling -Werror, and wait for the next
 > release of ModemManager.

 > Signed-off-by: Carlos Santos <casantos@datacom.ind.br>
 > ---
 >  package/modem-manager/modem-manager.mk | 6 ++++++
 >  1 file changed, 6 insertions(+)

 > diff --git a/package/modem-manager/modem-manager.mk b/package/modem-manager/modem-manager.mk
 > index 100c4a2941..ba4711b6c2 100644
 > --- a/package/modem-manager/modem-manager.mk
 > +++ b/package/modem-manager/modem-manager.mk
 > @@ -19,6 +19,12 @@ else
 >  MODEM_MANAGER_CONF_OPTS += --without-qmi
 >  endif
 
 > +define MODEM_MANAGER_REMOVE_WERROR
 > +	$(SED) 's: -Werror::' $(@D)/configure
 > +endef

-Werror seems to come from m4/compiler_warnings.m4:

AC_ARG_ENABLE(more-warnings,
        AS_HELP_STRING([--enable-more-warnings], [Maximum compiler warnings]),
        set_more_warnings="$enableval",set_more_warnings=yes)
AC_MSG_CHECKING(for more warnings, including -Werror)
if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
        AC_MSG_RESULT(yes)
        CFLAGS="-Wall -Werror -std=gnu89 $CFLAGS"

Wouldn't passing --disable-more-warnings work instead of hacking up
configure?

-- 
Bye, Peter Korsgaard