[PATCH][libgcc] Fix PR81080, build libgcov with large file support

[PATCH][libgcc] Fix PR81080, build libgcov with large file support

[Richard Biener]

The following patch makes sure we build the 32bit multilib libgcov with
large file support on x86_64-linux.  libgcov.h ends up using auto-host.h
via including tconfig.h which is only valid for the main multilib
(and on x86_64 doesn't need explicit large-file support defines).  That
libgcc ends up using that is probably from times where it wasn't at
the toplevel, some files already include auto-target.h generated by
libgcc configure but most do so after including tsystem.h which is
of course too late.  I suppose libgcc files shouldn't include tconfig.h
from gcc/, but that's a change going to far for this bug ;)

Thus, this makes libgcov.h include auto-target.h (but in the correct
position) plus adds AC_SYS_LARGEFILE to libgccs configure.

With that I properly end up with 32bit libgcov.a using fopen64 and open64
as fopen/open seem to fail for some filesystems and inode numbers that
do not fit 32bits even if the files in question are not large.  Failure
mode is:

int main(void) {
        return 0;
}

niffler:/home/mue/src # gcc -m32 --coverage -o t testit.c 
niffler:/home/mue/src # ./t 
profiling:/home/mue/src/testit.gcda:Cannot open

Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk and
branches after a while?

libgcov is the only libgcc module doing I/O.

Other than libgcov libgomp, libcilkrts, libmpx and libstdc++
are similarly affected (they use fopen on the 32bit multilib)
but not fixed.  libubsan, libasan, libssp, libbacktrace and libgfortran
use open.  While libgfortran configury has AC_SYS_LARGEFILE, the
open use leaks in through libbacktrace (ubsan/asan might have the
same issue, didn't investigate).  libbacktrace lacks AC_SYS_LARGEFILE.

Thanks,
Richard.

2017-06-14  Richard Biener  <rguenther@suse.de>

	PR gcov-profile/81080
	* configure.ac: Add AC_SYS_LARGEFILE.
	* libgcov.h: Include auto-target.h before tsystem.h to pick
	up _FILE_OFFSET_BITS which might differ for multilibs.
	* config.in: Regenerate.
	* configure: Likewise.

Index: libgcc/configure.ac
===================================================================
--- libgcc/configure.ac	(revision 249145)
+++ libgcc/configure.ac	(working copy)
@@ -191,6 +191,8 @@ GCC_NO_EXECUTABLES
 AC_PROG_CC
 AC_PROG_CPP_WERROR
 
+AC_SYS_LARGEFILE
+
 AC_CHECK_SIZEOF([double])
 AC_CHECK_SIZEOF([long double])
 AS_VAR_ARITH([double_type_size], [$ac_cv_sizeof_double \* 8])
Index: libgcc/libgcov.h
===================================================================
--- libgcc/libgcov.h	(revision 249145)
+++ libgcc/libgcov.h	(working copy)
@@ -38,6 +38,7 @@
 /* This path will be used by libgcov runtime.  */
 
 #include "tconfig.h"
+#include "auto-target.h"
 #include "tsystem.h"
 #include "coretypes.h"
 #include "tm.h"
Index: libgcc/config.in
===================================================================
--- libgcc/config.in	(revision 249145)
+++ libgcc/config.in	(working copy)
@@ -71,3 +71,9 @@
 
 /* Define to 1 if the target use emutls for thread-local storage. */
 #undef USE_EMUTLS
+
+/* Number of bits in a file offset, on hosts where this is settable. */
+#undef _FILE_OFFSET_BITS
+
+/* Define for large files, on AIX-style hosts. */
+#undef _LARGE_FILES
Index: libgcc/configure
===================================================================
--- libgcc/configure	(revision 249145)
+++ libgcc/configure	(working copy)
@@ -672,6 +672,7 @@ enable_version_specific_runtime_libs
 with_slibdir
 enable_maintainer_mode
 with_build_libsubdir
+enable_largefile
 enable_decimal_float
 with_system_libunwind
 enable_explicit_exception_frame_registration
@@ -1308,6 +1309,7 @@ Optional Features:
   --enable-maintainer-mode
                           enable make rules and dependencies not useful (and
                           sometimes confusing) to the casual installer
+  --disable-largefile     omit support for large files
   --enable-decimal-float={no,yes,bid,dpd}
 			enable decimal float extension to C.  Selecting 'bid'
 			or 'dpd' choses which decimal floating point format
@@ -4061,6 +4063,205 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 ac_c_preproc_warn_flag=yes
 
 
+# Check whether --enable-largefile was given.
+if test "${enable_largefile+set}" = set; then :
+  enableval=$enable_largefile;
+fi
+
+if test "$enable_largefile" != no; then
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for special C compiler options needed for large files" >&5
+$as_echo_n "checking for special C compiler options needed for large files... " >&6; }
+if test "${ac_cv_sys_largefile_CC+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_cv_sys_largefile_CC=no
+     if test "$GCC" != yes; then
+       ac_save_CC=$CC
+       while :; do
+	 # IRIX 6.2 and later do not support large files by default,
+	 # so use the C compiler's -n32 option if that helps.
+	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/types.h>
+ /* Check that off_t can represent 2**63 - 1 correctly.
+    We can't simply define LARGE_OFF_T to be 9223372036854775807,
+    since some C++ compilers masquerading as C compilers
+    incorrectly reject 9223372036854775807.  */
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
+		       && LARGE_OFF_T % 2147483647 == 1)
+		      ? 1 : -1];
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+	 if ac_fn_c_try_compile "$LINENO"; then :
+  break
+fi
+rm -f core conftest.err conftest.$ac_objext
+	 CC="$CC -n32"
+	 if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_sys_largefile_CC=' -n32'; break
+fi
+rm -f core conftest.err conftest.$ac_objext
+	 break
+       done
+       CC=$ac_save_CC
+       rm -f conftest.$ac_ext
+    fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_largefile_CC" >&5
+$as_echo "$ac_cv_sys_largefile_CC" >&6; }
+  if test "$ac_cv_sys_largefile_CC" != no; then
+    CC=$CC$ac_cv_sys_largefile_CC
+  fi
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _FILE_OFFSET_BITS value needed for large files" >&5
+$as_echo_n "checking for _FILE_OFFSET_BITS value needed for large files... " >&6; }
+if test "${ac_cv_sys_file_offset_bits+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  while :; do
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/types.h>
+ /* Check that off_t can represent 2**63 - 1 correctly.
+    We can't simply define LARGE_OFF_T to be 9223372036854775807,
+    since some C++ compilers masquerading as C compilers
+    incorrectly reject 9223372036854775807.  */
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
+		       && LARGE_OFF_T % 2147483647 == 1)
+		      ? 1 : -1];
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_sys_file_offset_bits=no; break
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#define _FILE_OFFSET_BITS 64
+#include <sys/types.h>
+ /* Check that off_t can represent 2**63 - 1 correctly.
+    We can't simply define LARGE_OFF_T to be 9223372036854775807,
+    since some C++ compilers masquerading as C compilers
+    incorrectly reject 9223372036854775807.  */
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
+		       && LARGE_OFF_T % 2147483647 == 1)
+		      ? 1 : -1];
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_sys_file_offset_bits=64; break
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  ac_cv_sys_file_offset_bits=unknown
+  break
+done
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_file_offset_bits" >&5
+$as_echo "$ac_cv_sys_file_offset_bits" >&6; }
+case $ac_cv_sys_file_offset_bits in #(
+  no | unknown) ;;
+  *)
+cat >>confdefs.h <<_ACEOF
+#define _FILE_OFFSET_BITS $ac_cv_sys_file_offset_bits
+_ACEOF
+;;
+esac
+rm -rf conftest*
+  if test $ac_cv_sys_file_offset_bits = unknown; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _LARGE_FILES value needed for large files" >&5
+$as_echo_n "checking for _LARGE_FILES value needed for large files... " >&6; }
+if test "${ac_cv_sys_large_files+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  while :; do
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/types.h>
+ /* Check that off_t can represent 2**63 - 1 correctly.
+    We can't simply define LARGE_OFF_T to be 9223372036854775807,
+    since some C++ compilers masquerading as C compilers
+    incorrectly reject 9223372036854775807.  */
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
+		       && LARGE_OFF_T % 2147483647 == 1)
+		      ? 1 : -1];
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_sys_large_files=no; break
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#define _LARGE_FILES 1
+#include <sys/types.h>
+ /* Check that off_t can represent 2**63 - 1 correctly.
+    We can't simply define LARGE_OFF_T to be 9223372036854775807,
+    since some C++ compilers masquerading as C compilers
+    incorrectly reject 9223372036854775807.  */
+#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
+		       && LARGE_OFF_T % 2147483647 == 1)
+		      ? 1 : -1];
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_sys_large_files=1; break
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  ac_cv_sys_large_files=unknown
+  break
+done
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_large_files" >&5
+$as_echo "$ac_cv_sys_large_files" >&6; }
+case $ac_cv_sys_large_files in #(
+  no | unknown) ;;
+  *)
+cat >>confdefs.h <<_ACEOF
+#define _LARGE_FILES $ac_cv_sys_large_files
+_ACEOF
+;;
+esac
+rm -rf conftest*
+  fi
+fi
+
+
 
 # The cast to long int works around a bug in the HP C Compiler
 # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects

Re: [PATCH][libgcc] Fix PR81080, build libgcov with large file support

[Joseph Myers]

On Wed, 14 Jun 2017, Richard Biener wrote:

> The following patch makes sure we build the 32bit multilib libgcov with
> large file support on x86_64-linux.  libgcov.h ends up using auto-host.h
> via including tconfig.h which is only valid for the main multilib
> (and on x86_64 doesn't need explicit large-file support defines).  That
> libgcc ends up using that is probably from times where it wasn't at
> the toplevel, some files already include auto-target.h generated by
> libgcc configure but most do so after including tsystem.h which is
> of course too late.  I suppose libgcc files shouldn't include tconfig.h
> from gcc/, but that's a change going to far for this bug ;)

tconfig.h shouldn't include host-specific configure test results (as the 
relevant bits of config.in should be conditioned on USED_FOR_TARGET), 
though that doesn't mean everything is indeed properly conditioned (and 
ideally we'd avoid configuration information from the gcc/ directory 
needing to be used in target libraries at all).

> Other than libgcov libgomp, libcilkrts, libmpx and libstdc++
> are similarly affected (they use fopen on the 32bit multilib)
> but not fixed.  libubsan, libasan, libssp, libbacktrace and libgfortran
> use open.  While libgfortran configury has AC_SYS_LARGEFILE, the
> open use leaks in through libbacktrace (ubsan/asan might have the
> same issue, didn't investigate).  libbacktrace lacks AC_SYS_LARGEFILE.

In general, watch out for off_t etc. as part of the ABI for such libraries 
(in which case AC_SYS_LARGEFILE could break the ABI).  And if the code 
uses fseek/ftell, it needs to change to fseeko/ftello (where available) to 
handle large offsets.

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [PATCH][libgcc] Fix PR81080, build libgcov with large file support

[Richard Biener]

On June 14, 2017 6:25:52 PM GMT+02:00, Joseph Myers <joseph@codesourcery.com> wrote:
>On Wed, 14 Jun 2017, Richard Biener wrote:
>
>> The following patch makes sure we build the 32bit multilib libgcov
>with
>> large file support on x86_64-linux.  libgcov.h ends up using
>auto-host.h
>> via including tconfig.h which is only valid for the main multilib
>> (and on x86_64 doesn't need explicit large-file support defines). 
>That
>> libgcc ends up using that is probably from times where it wasn't at
>> the toplevel, some files already include auto-target.h generated by
>> libgcc configure but most do so after including tsystem.h which is
>> of course too late.  I suppose libgcc files shouldn't include
>tconfig.h
>> from gcc/, but that's a change going to far for this bug ;)
>
>tconfig.h shouldn't include host-specific configure test results (as
>the 
>relevant bits of config.in should be conditioned on USED_FOR_TARGET), 
>though that doesn't mean everything is indeed properly conditioned (and
>
>ideally we'd avoid configuration information from the gcc/ directory 
>needing to be used in target libraries at all).

But it seems it assumes that the results are independent on the multilib variant which is exactly the problem here - the main multilib not needing _FILE_OFFSET_BITS=32 while the 32bit one does.

>> Other than libgcov libgomp, libcilkrts, libmpx and libstdc++
>> are similarly affected (they use fopen on the 32bit multilib)
>> but not fixed.  libubsan, libasan, libssp, libbacktrace and
>libgfortran
>> use open.  While libgfortran configury has AC_SYS_LARGEFILE, the
>> open use leaks in through libbacktrace (ubsan/asan might have the
>> same issue, didn't investigate).  libbacktrace lacks
>AC_SYS_LARGEFILE.
>
>In general, watch out for off_t etc. as part of the ABI for such
>libraries 
>(in which case AC_SYS_LARGEFILE could break the ABI).  And if the code 
>uses fseek/ftell, it needs to change to fseeko/ftello (where available)
>to 
>handle large offsets.

True.  Large files should be the very exception though.

Richard.

[PING] Re: [PATCH][libgcc] Fix PR81080, build libgcov with large file support

[Richard Biener]

On Wed, 14 Jun 2017, Richard Biener wrote:

> 
> The following patch makes sure we build the 32bit multilib libgcov with
> large file support on x86_64-linux.  libgcov.h ends up using auto-host.h
> via including tconfig.h which is only valid for the main multilib
> (and on x86_64 doesn't need explicit large-file support defines).  That
> libgcc ends up using that is probably from times where it wasn't at
> the toplevel, some files already include auto-target.h generated by
> libgcc configure but most do so after including tsystem.h which is
> of course too late.  I suppose libgcc files shouldn't include tconfig.h
> from gcc/, but that's a change going to far for this bug ;)
> 
> Thus, this makes libgcov.h include auto-target.h (but in the correct
> position) plus adds AC_SYS_LARGEFILE to libgccs configure.
> 
> With that I properly end up with 32bit libgcov.a using fopen64 and open64
> as fopen/open seem to fail for some filesystems and inode numbers that
> do not fit 32bits even if the files in question are not large.  Failure
> mode is:
> 
> int main(void) {
>         return 0;
> }
> 
> niffler:/home/mue/src # gcc -m32 --coverage -o t testit.c 
> niffler:/home/mue/src # ./t 
> profiling:/home/mue/src/testit.gcda:Cannot open
> 
> Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk and
> branches after a while?
> 
> libgcov is the only libgcc module doing I/O.
> 
> Other than libgcov libgomp, libcilkrts, libmpx and libstdc++
> are similarly affected (they use fopen on the 32bit multilib)
> but not fixed.  libubsan, libasan, libssp, libbacktrace and libgfortran
> use open.  While libgfortran configury has AC_SYS_LARGEFILE, the
> open use leaks in through libbacktrace (ubsan/asan might have the
> same issue, didn't investigate).  libbacktrace lacks AC_SYS_LARGEFILE.

Ping.

Richard.

> Thanks,
> Richard.
> 
> 2017-06-14  Richard Biener  <rguenther@suse.de>
> 
> 	PR gcov-profile/81080
> 	* configure.ac: Add AC_SYS_LARGEFILE.
> 	* libgcov.h: Include auto-target.h before tsystem.h to pick
> 	up _FILE_OFFSET_BITS which might differ for multilibs.
> 	* config.in: Regenerate.
> 	* configure: Likewise.
> 
> Index: libgcc/configure.ac
> ===================================================================
> --- libgcc/configure.ac	(revision 249145)
> +++ libgcc/configure.ac	(working copy)
> @@ -191,6 +191,8 @@ GCC_NO_EXECUTABLES
>  AC_PROG_CC
>  AC_PROG_CPP_WERROR
>  
> +AC_SYS_LARGEFILE
> +
>  AC_CHECK_SIZEOF([double])
>  AC_CHECK_SIZEOF([long double])
>  AS_VAR_ARITH([double_type_size], [$ac_cv_sizeof_double \* 8])
> Index: libgcc/libgcov.h
> ===================================================================
> --- libgcc/libgcov.h	(revision 249145)
> +++ libgcc/libgcov.h	(working copy)
> @@ -38,6 +38,7 @@
>  /* This path will be used by libgcov runtime.  */
>  
>  #include "tconfig.h"
> +#include "auto-target.h"
>  #include "tsystem.h"
>  #include "coretypes.h"
>  #include "tm.h"
> Index: libgcc/config.in
> ===================================================================
> --- libgcc/config.in	(revision 249145)
> +++ libgcc/config.in	(working copy)
> @@ -71,3 +71,9 @@
>  
>  /* Define to 1 if the target use emutls for thread-local storage. */
>  #undef USE_EMUTLS
> +
> +/* Number of bits in a file offset, on hosts where this is settable. */
> +#undef _FILE_OFFSET_BITS
> +
> +/* Define for large files, on AIX-style hosts. */
> +#undef _LARGE_FILES
> Index: libgcc/configure
> ===================================================================
> --- libgcc/configure	(revision 249145)
> +++ libgcc/configure	(working copy)
> @@ -672,6 +672,7 @@ enable_version_specific_runtime_libs
>  with_slibdir
>  enable_maintainer_mode
>  with_build_libsubdir
> +enable_largefile
>  enable_decimal_float
>  with_system_libunwind
>  enable_explicit_exception_frame_registration
> @@ -1308,6 +1309,7 @@ Optional Features:
>    --enable-maintainer-mode
>                            enable make rules and dependencies not useful (and
>                            sometimes confusing) to the casual installer
> +  --disable-largefile     omit support for large files
>    --enable-decimal-float={no,yes,bid,dpd}
>  			enable decimal float extension to C.  Selecting 'bid'
>  			or 'dpd' choses which decimal floating point format
> @@ -4061,6 +4063,205 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
>  ac_c_preproc_warn_flag=yes
>  
>  
> +# Check whether --enable-largefile was given.
> +if test "${enable_largefile+set}" = set; then :
> +  enableval=$enable_largefile;
> +fi
> +
> +if test "$enable_largefile" != no; then
> +
> +  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for special C compiler options needed for large files" >&5
> +$as_echo_n "checking for special C compiler options needed for large files... " >&6; }
> +if test "${ac_cv_sys_largefile_CC+set}" = set; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  ac_cv_sys_largefile_CC=no
> +     if test "$GCC" != yes; then
> +       ac_save_CC=$CC
> +       while :; do
> +	 # IRIX 6.2 and later do not support large files by default,
> +	 # so use the C compiler's -n32 option if that helps.
> +	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#include <sys/types.h>
> + /* Check that off_t can represent 2**63 - 1 correctly.
> +    We can't simply define LARGE_OFF_T to be 9223372036854775807,
> +    since some C++ compilers masquerading as C compilers
> +    incorrectly reject 9223372036854775807.  */
> +#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
> +  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
> +		       && LARGE_OFF_T % 2147483647 == 1)
> +		      ? 1 : -1];
> +int
> +main ()
> +{
> +
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +	 if ac_fn_c_try_compile "$LINENO"; then :
> +  break
> +fi
> +rm -f core conftest.err conftest.$ac_objext
> +	 CC="$CC -n32"
> +	 if ac_fn_c_try_compile "$LINENO"; then :
> +  ac_cv_sys_largefile_CC=' -n32'; break
> +fi
> +rm -f core conftest.err conftest.$ac_objext
> +	 break
> +       done
> +       CC=$ac_save_CC
> +       rm -f conftest.$ac_ext
> +    fi
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_largefile_CC" >&5
> +$as_echo "$ac_cv_sys_largefile_CC" >&6; }
> +  if test "$ac_cv_sys_largefile_CC" != no; then
> +    CC=$CC$ac_cv_sys_largefile_CC
> +  fi
> +
> +  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _FILE_OFFSET_BITS value needed for large files" >&5
> +$as_echo_n "checking for _FILE_OFFSET_BITS value needed for large files... " >&6; }
> +if test "${ac_cv_sys_file_offset_bits+set}" = set; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  while :; do
> +  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#include <sys/types.h>
> + /* Check that off_t can represent 2**63 - 1 correctly.
> +    We can't simply define LARGE_OFF_T to be 9223372036854775807,
> +    since some C++ compilers masquerading as C compilers
> +    incorrectly reject 9223372036854775807.  */
> +#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
> +  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
> +		       && LARGE_OFF_T % 2147483647 == 1)
> +		      ? 1 : -1];
> +int
> +main ()
> +{
> +
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +if ac_fn_c_try_compile "$LINENO"; then :
> +  ac_cv_sys_file_offset_bits=no; break
> +fi
> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> +  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#define _FILE_OFFSET_BITS 64
> +#include <sys/types.h>
> + /* Check that off_t can represent 2**63 - 1 correctly.
> +    We can't simply define LARGE_OFF_T to be 9223372036854775807,
> +    since some C++ compilers masquerading as C compilers
> +    incorrectly reject 9223372036854775807.  */
> +#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
> +  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
> +		       && LARGE_OFF_T % 2147483647 == 1)
> +		      ? 1 : -1];
> +int
> +main ()
> +{
> +
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +if ac_fn_c_try_compile "$LINENO"; then :
> +  ac_cv_sys_file_offset_bits=64; break
> +fi
> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> +  ac_cv_sys_file_offset_bits=unknown
> +  break
> +done
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_file_offset_bits" >&5
> +$as_echo "$ac_cv_sys_file_offset_bits" >&6; }
> +case $ac_cv_sys_file_offset_bits in #(
> +  no | unknown) ;;
> +  *)
> +cat >>confdefs.h <<_ACEOF
> +#define _FILE_OFFSET_BITS $ac_cv_sys_file_offset_bits
> +_ACEOF
> +;;
> +esac
> +rm -rf conftest*
> +  if test $ac_cv_sys_file_offset_bits = unknown; then
> +    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _LARGE_FILES value needed for large files" >&5
> +$as_echo_n "checking for _LARGE_FILES value needed for large files... " >&6; }
> +if test "${ac_cv_sys_large_files+set}" = set; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  while :; do
> +  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#include <sys/types.h>
> + /* Check that off_t can represent 2**63 - 1 correctly.
> +    We can't simply define LARGE_OFF_T to be 9223372036854775807,
> +    since some C++ compilers masquerading as C compilers
> +    incorrectly reject 9223372036854775807.  */
> +#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
> +  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
> +		       && LARGE_OFF_T % 2147483647 == 1)
> +		      ? 1 : -1];
> +int
> +main ()
> +{
> +
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +if ac_fn_c_try_compile "$LINENO"; then :
> +  ac_cv_sys_large_files=no; break
> +fi
> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> +  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#define _LARGE_FILES 1
> +#include <sys/types.h>
> + /* Check that off_t can represent 2**63 - 1 correctly.
> +    We can't simply define LARGE_OFF_T to be 9223372036854775807,
> +    since some C++ compilers masquerading as C compilers
> +    incorrectly reject 9223372036854775807.  */
> +#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
> +  int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
> +		       && LARGE_OFF_T % 2147483647 == 1)
> +		      ? 1 : -1];
> +int
> +main ()
> +{
> +
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +if ac_fn_c_try_compile "$LINENO"; then :
> +  ac_cv_sys_large_files=1; break
> +fi
> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> +  ac_cv_sys_large_files=unknown
> +  break
> +done
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sys_large_files" >&5
> +$as_echo "$ac_cv_sys_large_files" >&6; }
> +case $ac_cv_sys_large_files in #(
> +  no | unknown) ;;
> +  *)
> +cat >>confdefs.h <<_ACEOF
> +#define _LARGE_FILES $ac_cv_sys_large_files
> +_ACEOF
> +;;
> +esac
> +rm -rf conftest*
> +  fi
> +fi
> +
> +
>  
>  # The cast to long int works around a bug in the HP C Compiler
>  # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)

Re: [PATCH][libgcc] Fix PR81080, build libgcov with large file support

[Ian Lance Taylor via gcc-patches]

On Wed, Jun 14, 2017 at 1:01 AM, Richard Biener <rguenther@suse.de> wrote:
>
> The following patch makes sure we build the 32bit multilib libgcov with
> large file support on x86_64-linux.  libgcov.h ends up using auto-host.h
> via including tconfig.h which is only valid for the main multilib
> (and on x86_64 doesn't need explicit large-file support defines).  That
> libgcc ends up using that is probably from times where it wasn't at
> the toplevel, some files already include auto-target.h generated by
> libgcc configure but most do so after including tsystem.h which is
> of course too late.  I suppose libgcc files shouldn't include tconfig.h
> from gcc/, but that's a change going to far for this bug ;)
>
> Thus, this makes libgcov.h include auto-target.h (but in the correct
> position) plus adds AC_SYS_LARGEFILE to libgccs configure.
>
> With that I properly end up with 32bit libgcov.a using fopen64 and open64
> as fopen/open seem to fail for some filesystems and inode numbers that
> do not fit 32bits even if the files in question are not large.  Failure
> mode is:
>
> int main(void) {
>         return 0;
> }
>
> niffler:/home/mue/src # gcc -m32 --coverage -o t testit.c
> niffler:/home/mue/src # ./t
> profiling:/home/mue/src/testit.gcda:Cannot open
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk and
> branches after a while?
>
> libgcov is the only libgcc module doing I/O.
>
> Other than libgcov libgomp, libcilkrts, libmpx and libstdc++
> are similarly affected (they use fopen on the 32bit multilib)
> but not fixed.  libubsan, libasan, libssp, libbacktrace and libgfortran
> use open.  While libgfortran configury has AC_SYS_LARGEFILE, the
> open use leaks in through libbacktrace (ubsan/asan might have the
> same issue, didn't investigate).  libbacktrace lacks AC_SYS_LARGEFILE.
>
> Thanks,
> Richard.
>
> 2017-06-14  Richard Biener  <rguenther@suse.de>
>
>         PR gcov-profile/81080
>         * configure.ac: Add AC_SYS_LARGEFILE.
>         * libgcov.h: Include auto-target.h before tsystem.h to pick
>         up _FILE_OFFSET_BITS which might differ for multilibs.
>         * config.in: Regenerate.
>         * configure: Likewise.


This is OK.

Thanks.

Ian