Build filesystem library with large file support

Enable AC_SYS_LARGEFILE to set the macros needed for large file APIs to
be used by default. We do not want to define those macros in the
public headers that users include. The values of the macros are copied
to a separate file that is only included by the filesystem sources
during the build, and then the macros in <bits/c++config.h> are renamed
so that they don't have any effect in user code including our headers.

Also use larger type for result of filesystem::file_size to avoid
truncation of large values on 32-bit systems (PR 91947).

	PR libstdc++/81091
	PR libstdc++/91947
	* configure.ac: Use AC_SYS_LARGEFILE to enable 64-bit file APIs.
	* config.h.in: Regenerate:
	* configure: Regenerate:
	* include/Makefile.am (${host_builddir}/largefile-config.h): New
	target to generate config header for filesystem library.
	(${host_builddir}/c++config.h): Rename macros for large file support.
	* include/Makefile.in: Regenerate.
	* src/c++17/fs_dir.cc: Include new config header.
	* src/c++17/fs_ops.cc: Likewise.
	(filesystem::file_size): Use uintmax_t for size.
	* src/filesystem/dir.cc: Include new config header.
	* src/filesystem/ops.cc: Likewise.
	(experimental::filesystem::file_size): Use uintmax_t for size.

From-SVN: r276585

1 files changed, 213 insertions, 10 deletions

diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index e646c41..cb67581 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -895,6 +895,7 @@ ac_user_opts='
 enable_option_checking
 enable_multilib
 enable_silent_rules
+enable_largefile
 with_target_subdir
 with_cross_host
 with_newlib
@@ -1579,6 +1580,7 @@ Optional Features:
   --enable-multilib       build many library versions (default)
   --enable-silent-rules   less verbose build output (undo: "make V=1")
   --disable-silent-rules  verbose build output (undo: "make V=0")
+  --disable-largefile     omit support for large files
   --enable-maintainer-mode
                           enable make rules and dependencies not useful (and
                           sometimes confusing) to the casual installer
@@ -4928,9 +4930,210 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 CXXFLAGS="$save_CXXFLAGS"
 
+
+# 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 ${ac_cv_sys_largefile_CC+:} false; 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 ${ac_cv_sys_file_offset_bits+:} false; 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 ${ac_cv_sys_large_files+:} false; 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 $ac_cv_sys_large_files
+_ACEOF
+;;
+esac
+rm -rf conftest*
+  fi
+
+
+fi
+
+
 # Runs configure.host, and assorted other critical bits.  Sets
 # up critical shell variables.
-
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -11850,7 +12053,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11853 "configure"
+#line 12056 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11956,7 +12159,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11959 "configure"
+#line 12162 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -15648,7 +15851,7 @@ $as_echo "$glibcxx_cv_atomic_long_long" >&6; }
   # Fake what AC_TRY_COMPILE does.
 
     cat > conftest.$ac_ext << EOF
-#line 15651 "configure"
+#line 15854 "configure"
 int main()
 {
   typedef bool atomic_type;
@@ -15683,7 +15886,7 @@ $as_echo "$glibcxx_cv_atomic_bool" >&6; }
     rm -f conftest*
 
     cat > conftest.$ac_ext << EOF
-#line 15686 "configure"
+#line 15889 "configure"
 int main()
 {
   typedef short atomic_type;
@@ -15718,7 +15921,7 @@ $as_echo "$glibcxx_cv_atomic_short" >&6; }
     rm -f conftest*
 
     cat > conftest.$ac_ext << EOF
-#line 15721 "configure"
+#line 15924 "configure"
 int main()
 {
   // NB: _Atomic_word not necessarily int.
@@ -15754,7 +15957,7 @@ $as_echo "$glibcxx_cv_atomic_int" >&6; }
     rm -f conftest*
 
     cat > conftest.$ac_ext << EOF
-#line 15757 "configure"
+#line 15960 "configure"
 int main()
 {
   typedef long long atomic_type;
@@ -15907,7 +16110,7 @@ $as_echo "mutex" >&6; }
   # unnecessary for this test.
 
     cat > conftest.$ac_ext << EOF
-#line 15910 "configure"
+#line 16113 "configure"
 int main()
 {
   _Decimal32 d1;
@@ -15949,7 +16152,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
   # unnecessary for this test.
 
     cat > conftest.$ac_ext << EOF
-#line 15952 "configure"
+#line 16155 "configure"
 template<typename T1, typename T2>
   struct same
   { typedef T2 type; };
@@ -15983,7 +16186,7 @@ $as_echo "$enable_int128" >&6; }
     rm -f conftest*
 
     cat > conftest.$ac_ext << EOF
-#line 15986 "configure"
+#line 16189 "configure"
 template<typename T1, typename T2>
   struct same
   { typedef T2 type; };