RE: [PATCH, Android] MIPS support

["Fu, Chao-Ying" <fu@mips.com>]

Maxim Kuvyrkov wrote:

> > 
> >> For now, two MIPS changes in gnu-user.h and 
> unwind-dw2-fde-dip.c can be posted for comment.
> >> (I didn't tested this patch, though.)
> 
> You need to test your patches before posting them for review. 
>  Below are a couple of comments on your current version.

  I can test if this patch doesn't break existing MIPS Linux GCC build.

> 
> >> After starting to build toolchains for Android with 
> Bionic, we may find new files to
> >> patch.  Ex: Comment out getpagesize() for bionic.
> >> 
> >> Any comment?  Thanks a lot!
> >> 
> >> Regards,
> >> Chao-ying
> >> 
> >> Index: gcc/gcc/config/mips/gnu-user.h
> >> ===================================================================
> >> --- gcc.orig/gcc/config/mips/gnu-user.h	2012-04-03 
> 17:39:50.000000000 -0700
> >> +++ gcc/gcc/config/mips/gnu-user.h	2012-04-04 
> 14:31:50.804236000 -0700
> >> @@ -45,8 +45,8 @@ along with GCC; see the file COPYING3.  
> >> /* A standard GNU/Linux mapping.  On most targets, it is 
> included in
> >>   CC1_SPEC itself by config/linux.h, but mips.h overrides CC1_SPEC
> >>   and provides this hook instead.  */
> >> -#undef SUBTARGET_CC1_SPEC
> >> -#define SUBTARGET_CC1_SPEC "%{profile:-p}"
> >> +#undef GNU_USER_SUBTARGET_CC1_SPEC
> >> +#define GNU_USER_SUBTARGET_CC1_SPEC "%{profile:-p}"
> >> 
> >> /* -G is incompatible with -KPIC which is the default, so 
> only allow objects
> >>   in the small data section if the user explicitly asks for it.  */
> >> @@ -54,8 +54,8 @@ along with GCC; see the file COPYING3.  
> >> #define MIPS_DEFAULT_GVALUE 0
> >> 
> >> /* Borrowed from sparc/linux.h */
> >> -#undef LINK_SPEC
> >> -#define LINK_SPEC \
> >> +#undef GNU_USER_TARGET_LINK_SPEC
> >> +#define GNU_USER_TARGET_LINK_SPEC \
> >> "%(endian_spec) \
> >>  %{shared:-shared} \
> >>  %{!shared: \
> >> @@ -89,8 +89,8 @@ along with GCC; see the file COPYING3.  
> >> #undef ASM_OUTPUT_REG_PUSH
> >> #undef ASM_OUTPUT_REG_POP
> >> 
> >> -#undef LIB_SPEC
> >> -#define LIB_SPEC "\
> >> +#undef GNU_USER_TARGET_LIB_SPEC
> >> +#define GNU_USER_TARGET_LIB_SPEC "\
> >> %{pthread:-lpthread} \
> >> %{shared:-lc} \
> >> %{!shared: \
> >> @@ -133,7 +133,34 @@ extern const char *host_detect_local_cpu
> >>  LINUX_DRIVER_SELF_SPECS
> >> 
> >> /* Similar to standard Linux, but adding -ffast-math support.  */
> >> -#undef  ENDFILE_SPEC
> >> -#define ENDFILE_SPEC \
> >> +#undef  GNU_USER_TARGET_ENDFILE_SPEC
> >> +#define GNN_USER_TARGET_ENDFILE_SPEC \
> >>  "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
> >>   %{shared|pie:crtendS.o%s;:crtend.o%s} crtn.o%s"
> 
> Above definitions are OK.

  Thanks!

> 
> >> +
> >> +#undef  LINK_SPEC
> >> +#define LINK_SPEC						
> 	\
> >> +  LINUX_OR_ANDROID_LD (GNU_USER_TARGET_LINK_SPEC,		
> 	\
> >> +		       GNU_USER_TARGET_LINK_SPEC " " ANDROID_LINK_SPEC)
> >> +
> >> +#undef  SUBTARGET_CC1_SPEC
> >> +#define SUBTARGET_CC1_SPEC				
> 		\
> >> +  LINUX_OR_ANDROID_CC (GNU_USER_SUBTARGET_CC1_SPEC,	
> 		\
> >> +		       GNU_USER_SUBTARGET_CC1_SPEC " " ANDROID_CC1_SPEC)
> >> +
> >> +#undef  CC1PLUS_SPEC
> >> +#define CC1PLUS_SPEC					
> 		\
> >> +  LINUX_OR_ANDROID_CC ("", ANDROID_CC1PLUS_SPEC)
> >> +
> >> +#undef  LIB_SPEC
> >> +#define LIB_SPEC						
> 	\
> >> +  LINUX_OR_ANDROID_LD (GNU_USER_TARGET_LIB_SPEC,		
> 	\
> >> +		       GNU_USER_TARGET_LIB_SPEC " " ANDROID_LIB_SPEC)
> >> +
> >> +#undef  STARTFILE_SPEC
> >> +#define STARTFILE_SPEC					
> 		\
> >> +  LINUX_OR_ANDROID_LD (GNU_USER_TARGET_STARTFILE_SPEC, 
> ANDROID_STARTFILE_SPEC)
> >> +
> >> +#undef  ENDFILE_SPEC
> >> +#define ENDFILE_SPEC					
> 		\
> >> +  LINUX_OR_ANDROID_LD (GNU_USER_TARGET_ENDFILE_SPEC, 
> ANDROID_ENDFILE_SPEC)
> 
> The LINUX_OR_ANDROID_* definitions should be moved out of 
> gnu-user.h, as this header is used for systems besides Linux, 
> e.g., kFreeBSD and Hurd.  Please move these definitions to 
> mips/linux-common.h, which will be a new file, similarly as 
> i386 did in http://gcc.gnu.org/ml/gcc-patches/2012-04/msg00944.html .

  I will check this message.

> 
> >> Index: gcc/libgcc/unwind-dw2-fde-dip.c
> >> ===================================================================
> >> --- gcc.orig/libgcc/unwind-dw2-fde-dip.c	2012-04-03 
> 17:07:28.000000000 -0700
> >> +++ gcc/libgcc/unwind-dw2-fde-dip.c	2012-04-04 
> 14:51:01.338074000 -0700
> >> @@ -48,8 +48,9 @@
> >> #include "gthr.h"
> >> 
> >> #if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
> >> -    && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
> >> -	|| (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && 
> defined(DT_CONFIG)))
> >> +    && ((defined(__BIONIC__) && (defined(mips) || 
> defined(__mips__))) \
> >> +        || (__GLIBC__ > 2 || (__GLIBC__ == 2 && 
> __GLIBC_MINOR__ > 2) \
> >> +	|| (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && 
> defined(DT_CONFIG))))
> >> # define USE_PT_GNU_EH_FRAME
> >> #endif
> 
> What is this change for?

  For stack unwinding, MIPS needs supporting functions in libgcc to 
work with eh_frame for Android.
(Note that ARM has its own unwinding functions in gcc/config/arm/.  It doesn't use eh_frame.)
The file is enabled for GLIBC originally.  Thus, I add a new test to enable it
for MIPS Android BIONIC build.

  Thanks!

Regards,
Chao-ying