[PATCH, libstdc++]: Fix configure check for linux/random.h

[Uros Bizjak]

Hello!

linux/random.h uses __u32 types, which are defined through inclusion
of linux/types.h header. On some older systems (e.g. CentOS 5.11)
linux/random.h doesn't include linux/types.h by itself, and configure
declares found linux/random.h as unusable.

Attached patch fixes detection by including linux/types.h in the
configure check.

2018-01-18  Uros Bizjak  <ubiz...@gmail.com>

    * configure.ac (AC_CHECK_HEADERS): Add linux/types.h.  Conditionally
    include linux/types.h when checking linux/random.h header.
    * config.h.in: Regenerate.
    * configure: Ditto.
    * src/c++11/random.cc: Conditionally include linux/types.h.

Patch was bootstrapped and regression tested on x86_64-linux-gnu
{,-m32} CentOS 5.11 and Fedora 26.

OK for mainline?

Uros.

diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index e31e054..5a0f067 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -270,6 +270,9 @@
 /* Define to 1 if you have the <linux/random.h> header file. */
 #undef HAVE_LINUX_RANDOM_H
 
+/* Define to 1 if you have the <linux/types.h> header file. */
+#undef HAVE_LINUX_TYPES_H
+
 /* Define to 1 if you have the <locale.h> header file. */
 #undef HAVE_LOCALE_H
 
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index f5798d3..69845f4 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -21799,7 +21799,7 @@ for ac_header in endian.h execinfo.h float.h fp.h 
ieeefp.h inttypes.h \
 locale.h machine/endian.h machine/param.h nan.h stdint.h stdlib.h string.h \
 strings.h sys/ipc.h sys/isa_defs.h sys/machine.h sys/param.h \
 sys/resource.h sys/sem.h sys/stat.h sys/time.h sys/types.h unistd.h \
-wchar.h wctype.h linux/random.h
+wchar.h wctype.h linux/types.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" 
"$ac_includes_default"
@@ -21814,6 +21814,23 @@ fi
 done
 
 
+for ac_header in linux/random.h
+do :
+  ac_fn_c_check_header_compile "$LINENO" "linux/random.h" 
"ac_cv_header_linux_random_h" "#ifdef HAVE_LINUX_TYPES_H
+# include <linux/types.h>
+#endif
+
+"
+if test "x$ac_cv_header_linux_random_h" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LINUX_RANDOM_H 1
+_ACEOF
+
+fi
+
+done
+
+
 # Only do link tests if native. Else, hardcode.
 if $GLIBCXX_IS_NATIVE; then
 
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index c90c509..e110f57 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -237,7 +237,13 @@ AC_CHECK_HEADERS([endian.h execinfo.h float.h fp.h 
ieeefp.h inttypes.h \
 locale.h machine/endian.h machine/param.h nan.h stdint.h stdlib.h string.h \
 strings.h sys/ipc.h sys/isa_defs.h sys/machine.h sys/param.h \
 sys/resource.h sys/sem.h sys/stat.h sys/time.h sys/types.h unistd.h \
-wchar.h wctype.h linux/random.h])
+wchar.h wctype.h linux/types.h])
+
+AC_CHECK_HEADERS([linux/random.h], [], [],
+[[#ifdef HAVE_LINUX_TYPES_H
+# include <linux/types.h>
+#endif
+]])
 
 # Only do link tests if native. Else, hardcode.
 if $GLIBCXX_IS_NATIVE; then
diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc
index 415f794..19daf6d 100644
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -42,6 +42,10 @@
 # include <sys/ioctl.h>
 #endif
 
+#ifdef _GLIBCXX_HAVE_LINUX_TYPES_H
+# include <linux/types.h>
+#endif
+
 #ifdef _GLIBCXX_HAVE_LINUX_RANDOM_H
 # include <linux/random.h>
 #endif