Re: sys/types.h on Android includes stdint.h before defining time_t

[Bruno Haible]

Hi Simon,

Thanks for the report.

> I think it helps, but it wasn't complete.  Below is a new
> backtrace.  It seems the system wchar.h includes the system time.h,
> which triggers the same problem...  that may be harder to fix?
> 
> arm-linux-androideabi-gcc
> --sysroot /home/jas/android-ndk-r7/platforms/android-8/arch-arm
> -DHAVE_CONFIG_H -I. -I..  -DGNULIB_STRICT_CHECKING=1   -g -O2 -MT
> vasnprintf.o -MD -MP -MF .deps/vasnprintf.Tpo -c -o vasnprintf.o
> vasnprintf.c
> In file included
> from 
> /home/jas/android-ndk-r7/platforms/android-8/arch-arm/usr/include/sys/time.h:33,
> 
> from 
> /home/jas/android-ndk-r7/platforms/android-8/arch-arm/usr/include/time.h:32,
> 
> from 
> /home/jas/android-ndk-r7/platforms/android-8/arch-arm/usr/include/wchar.h:39,
>                  from ./wchar.h:81,
>                  from ./stdint.h:531,
> 
> from 
> /home/jas/android-ndk-r7/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.4.3/include-fixed/sys/types.h:43,
> 
> from 
> /home/jas/android-ndk-r7/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.4.3/include-fixed/stdio.h:64,
>                  from ./stdio.h:44,
>                  from vasnprintf.c:71:
> /home/jas/android-ndk-r7/platforms/android-8/arch-arm/usr/include/linux/time.h:20:
>  error: expected specifier-qualifier-list before 'time_t'

I reproduce the same issue, after having tweaked stdint.h and wchar.h
like Paul did:

In file included from 
/cross/android-ndk-r7/platforms/android-8/arch-arm/usr/include/sys/time.h:33,
                 from 
/cross/android-ndk-r7/platforms/android-8/arch-arm/usr/include/time.h:32,
                 from 
/cross/android-ndk-r7/platforms/android-8/arch-arm/usr/include/wchar.h:39,
                 from ./wchar.h:48,
                 from ./stdint.h:531,
                 from 
/cross/android-ndk-r7/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.4.3/include-fixed/sys/types.h:43,
                 from 
/cross/android-ndk-r7/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.4.3/include-fixed/stdio.h:64,
                 from ./stdio.h:44,
                 from ./wchar.h:72,
                 from printf-args.h:42,
                 from printf-args.c:30:
/cross/android-ndk-r7/platforms/android-8/arch-arm/usr/include/linux/time.h:20: 
error: expected specifier-qualifier-list before 'time_t'

Your analysis is right, and you have already nicely summarized in the
subject: The problem is that include-fixed/sys/types.h contains

  at line 43:     #include <stdint.h>
  at line 113:    typedef __kernel_time_t       time_t;

So what we have to do, is to change our stdint.h replacement so that
it avoids to #include any headers that might need time_t, if it is
included from <sys/types.h>.

There are two ways of implementing this:

1) Override sys/types.h also on android/bionic systems, so that it
   contains a
     #define _GL_INCLUDING_SYS_TYPES_H
   at the beginning and a
     #undef _GL_INCLUDING_SYS_TYPES_H
   at the end, and change stdint.h to just include the system's <stdint.h>
   when _GL_INCLUDING_SYS_TYPES_H is defined.

   Or (this is just a variant):

   Override sys/types.h also on android/bionic systems, so that it
   contains a
     #define _GL_JUST_INCLUDE_SYSTEM_STDINT_H
   at the beginning and a
     #undef _GL_JUST_INCLUDE_SYSTEM_STDINT_H
   at the end. Our stdint.h already obeys _GL_JUST_INCLUDE_SYSTEM_STDINT_H.

2) Change stdint.h to just include the system's <stdint.h> when
   __BIONIC__ and _SYS_TYPES_H_ are defined but _SSIZE_T_DEFINED_ is not
   yet defined.

The latter is simpler (does not require to override sys/types.h), so I'm
applying that.

> > Another possibility would be to remove all BSD/OS hacks in gnulib.
> > BSD/OS hasn't been supported since 2004, according to Wikipedia,
> > and perhaps it's time we retire it from gnulib.
> 
> I wouldn't object to this, it was a long time since I heard anything
> about BSD/OS.

Actually it turns out that with the main problem fixed in stdint.h, Paul's
changes are not needed.


2012-01-21  Bruno Haible  <address@hidden>

        stdint: Add support for Android.
        * lib/stdint.in.h: When included from Bionic <sys/types.h>, just
        include the system's <stdint.h>.
        Reported by Simon Josefsson <address@hidden>.

--- lib/stdint.in.h.orig        Sat Jan 21 13:08:10 2012
+++ lib/stdint.in.h     Sat Jan 21 13:05:26 2012
@@ -34,6 +34,14 @@
    <inttypes.h>.  */
 #define _GL_JUST_INCLUDE_SYSTEM_INTTYPES_H
 
+/* On Android (Bionic libc), <sys/types.h> includes this file before
+   having defined 'time_t'.  Therefore in this case avoid including
+   other system header files; just include the system's <stdint.h>.  */
+#if defined __BIONIC__ \
+    && defined _SYS_TYPES_H_ && !defined _SSIZE_T_DEFINED_
+# @INCLUDE_NEXT@ @NEXT_STDINT_H@
+#else
+
 /* Get those types that are already defined in other system include
    files, so that we can "#define int8_t signed char" below without
    worrying about a later system include file containing a "typedef
@@ -606,4 +614,5 @@
 #endif
 
 #endif /* address@hidden@_STDINT_H */
+#endif /* !(defined __BIONIC__ && ...) */
 #endif /* !defined address@hidden@_STDINT_H && !defined 
_GL_JUST_INCLUDE_SYSTEM_STDINT_H */