[Buildroot] [PATCH] xserver_xorg-server: disable libunwind on MIPS with 32-bit pointers

[Buildroot] [PATCH] xserver_xorg-server: disable libunwind on MIPS with 32-bit pointers

[Vicente Olivert Riera]

libunwind support in xorg-server is not only broken for MIPS64 n32 but
for all MIPS variants with 32-bit pointers. The reason is exactly the
same one. libunwind defines a uint64 variable to store the words. Then,
xorg-server casts that variable (64-bit) into a pointer (32-bit), and
the compilation fails:

backtrace.c:98:13: error: cast to pointer from integer of different size
[-Werror=int-to-pointer-cast]

Related:
  https://bugs.freedesktop.org/show_bug.cgi?id=79939

Fixes:
  http://autobuild.buildroot.net/results/87b/87be2c95957f9925c1258812e536df72689fc5da/

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
---
 .../xserver_xorg-server/xserver_xorg-server.mk     |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk b/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk
index 4164ccf..91b4f03 100644
--- a/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk
+++ b/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk
@@ -144,10 +144,11 @@ ifeq ($(BR2_PACKAGE_FREETYPE),y)
 XSERVER_XORG_SERVER_DEPENDENCIES += freetype
 endif
 
-# libunwind support is broken on MIPS64 n32
+# libunwind support is broken on all MIPS variants with 32-bit pointers
 # https://bugs.freedesktop.org/show_bug.cgi?id=79939
-ifeq ($(BR2_PACKAGE_LIBUNWIND)-$(BR2_MIPS_NABI32),y-)
+ifeq ($(BR2_PACKAGE_LIBUNWIND)-$(BR2_MIPS_OABI32)-$(BR2_MIPS_NABI32),y--)
 XSERVER_XORG_SERVER_DEPENDENCIES += libunwind
+XSERVER_XORG_SERVER_CONF_OPTS += --enable-libunwind
 else
 XSERVER_XORG_SERVER_CONF_OPTS += --disable-libunwind
 endif
-- 
1.7.1

[Buildroot] [PATCH] xserver_xorg-server: disable libunwind on MIPS with 32-bit pointers

[Thomas Petazzoni]

Dear Vicente Olivert Riera,

On Fri, 5 Dec 2014 11:17:02 +0000, Vicente Olivert Riera wrote:
> libunwind support in xorg-server is not only broken for MIPS64 n32 but
> for all MIPS variants with 32-bit pointers. The reason is exactly the
> same one. libunwind defines a uint64 variable to store the words. Then,
> xorg-server casts that variable (64-bit) into a pointer (32-bit), and
> the compilation fails:
> 
> backtrace.c:98:13: error: cast to pointer from integer of different size
> [-Werror=int-to-pointer-cast]
> 
> Related:
>   https://bugs.freedesktop.org/show_bug.cgi?id=79939
> 
> Fixes:
>   http://autobuild.buildroot.net/results/87b/87be2c95957f9925c1258812e536df72689fc5da/
> 
> Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>

Applied, thanks.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH] xserver_xorg-server: disable libunwind on MIPS with 32-bit pointers

[Peter Korsgaard]

>>>>> "Vicente" == Vicente Olivert Riera <Vincent.Riera@imgtec.com> writes:

Hi,

 > libunwind support in xorg-server is not only broken for MIPS64 n32 but
 > for all MIPS variants with 32-bit pointers. The reason is exactly the
 > same one. libunwind defines a uint64 variable to store the words. Then,
 > xorg-server casts that variable (64-bit) into a pointer (32-bit), and
 > the compilation fails:

 > backtrace.c:98:13: error: cast to pointer from integer of different size
 > [-Werror=int-to-pointer-cast]

 > Related:
 >   https://bugs.freedesktop.org/show_bug.cgi?id=79939

 > Fixes:
 >   http://autobuild.buildroot.net/results/87b/87be2c95957f9925c1258812e536df72689fc5da/

 > Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
 > ---
 >  .../xserver_xorg-server/xserver_xorg-server.mk     |    5 +++--
 >  1 files changed, 3 insertions(+), 2 deletions(-)

 > diff --git a/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk b/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk
 > index 4164ccf..91b4f03 100644
 > --- a/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk
 > +++ b/package/x11r7/xserver_xorg-server/xserver_xorg-server.mk
 > @@ -144,10 +144,11 @@ ifeq ($(BR2_PACKAGE_FREETYPE),y)
 >  XSERVER_XORG_SERVER_DEPENDENCIES += freetype
 >  endif
 
 > -# libunwind support is broken on MIPS64 n32
 > +# libunwind support is broken on all MIPS variants with 32-bit pointers
 >  # https://bugs.freedesktop.org/show_bug.cgi?id=79939
 > -ifeq ($(BR2_PACKAGE_LIBUNWIND)-$(BR2_MIPS_NABI32),y-)
 > +ifeq ($(BR2_PACKAGE_LIBUNWIND)-$(BR2_MIPS_OABI32)-$(BR2_MIPS_NABI32),y--)

The dash (-) between _OABI32 and _NABI32 is not strictly needed. The
only reason we had it before is that we wanted to detect libunwind AND
!NABI32, so when they expand to 'y' and '', and not confuse it with
!libunwind ('') AND NABI32 ('y'), so we needed a separator.

-- 
Bye, Peter Korsgaard