Import the strerror_r-posix module and use it in GDB.

Makes sure to assign the return value of strerror_r to an int,
so that we get a compile error if we accidentally get the
wrong version.

gdb/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* config.in: Regenerate.
	* configure: Regenerate.
	* gdbsupport/common.m4: No longer check for strerror_r.
	* gdbsupport/posix-strerror.c (safe_strerror): Always call the
	POSIX version of strerror_r, now that gnulib provides it if
	necessary.

gdb/gdbserver/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* config.in: Regenerate.
	* configure: Regenerate.

gnulib/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* config.in: Regenerate.
	* configure: Regenerate.
	* import/Makefile.am: Update.
	* import/Makefile.in: Regenerate.
	* import/extra/config.rpath: New file.
	* import/glthread/lock.c: New file.
	* import/glthread/lock.h: New file.
	* import/glthread/threadlib.c: New file.
	* import/m4/gnulib-cache.m4: Update.
	* import/m4/gnulib-comp.m4: Update.
	* import/m4/lib-ld.m4: New file.
	* import/m4/lib-link.m4: New file.
	* import/m4/lib-prefix.m4: New file.
	* import/m4/lock.m4: New file.
	* import/m4/strerror_r.m4: New file.
	* import/m4/threadlib.m4: New file.
	* import/strerror_r.c: New file.
	* update-gnulib.sh: Import strerror_r-posix.

Change-Id: I5cfeb12a5203a4cd94a78581541e6085a68685c3

8 files changed, 26 insertions, 28 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 134c883..0f92504 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2019-11-15  Christian Biesinger  <cbiesinger@google.com>
+
+	* config.in: Regenerate.
+	* configure: Regenerate.
+	* gdbsupport/common.m4: No longer check for strerror_r.
+	* gdbsupport/posix-strerror.c (safe_strerror): Always call the
+	POSIX version of strerror_r, now that gnulib provides it if
+	necessary.
+
 2019-11-14  Christian Biesinger  <cbiesinger@google.com>
 
 	* README (`configure' options): Update.
diff --git a/gdb/config.in b/gdb/config.in
index 5a21fca..fc05f15 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -423,9 +423,6 @@
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
-/* Define to 1 if you have the `strerror_r' function. */
-#undef HAVE_STRERROR_R
-
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
diff --git a/gdb/configure b/gdb/configure
index 512f016..e805903 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -13480,7 +13480,7 @@ done
 
 
   for ac_func in fdwalk getrlimit pipe pipe2 socketpair sigaction \
-		  sigprocmask strerror_r
+		  sigprocmask
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index e17a7ca..0f0fc03 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2019-11-15  Christian Biesinger  <cbiesinger@google.com>
+
+	* config.in: Regenerate.
+	* configure: Regenerate.
+
 2019-11-12  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* ax.c (ax_printf): Handle size_t_arg.
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 2984281..0bce18d 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -229,9 +229,6 @@
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
-/* Define to 1 if you have the `strerror_r' function. */
-#undef HAVE_STRERROR_R
-
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 3f1f1c1..e513fc5 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -6822,7 +6822,7 @@ done
 
 
   for ac_func in fdwalk getrlimit pipe pipe2 socketpair sigaction \
-		  sigprocmask strerror_r
+		  sigprocmask
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/gdb/gdbsupport/common.m4 b/gdb/gdbsupport/common.m4
index 2e44cf4..471d705 100644
--- a/gdb/gdbsupport/common.m4
+++ b/gdb/gdbsupport/common.m4
@@ -33,7 +33,7 @@ AC_DEFUN([GDB_AC_COMMON], [
 		   dlfcn.h)
 
   AC_CHECK_FUNCS([fdwalk getrlimit pipe pipe2 socketpair sigaction \
-		  sigprocmask strerror_r])
+		  sigprocmask])
 
   AC_CHECK_DECLS([strerror, strstr])
 
diff --git a/gdb/gdbsupport/posix-strerror.c b/gdb/gdbsupport/posix-strerror.c
index 34420cf..107813f 100644
--- a/gdb/gdbsupport/posix-strerror.c
+++ b/gdb/gdbsupport/posix-strerror.c
@@ -18,6 +18,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "common-defs.h"
+#include <string.h>
 
 /* Implementation of safe_strerror as defined in common-utils.h.  */
 
@@ -26,23 +27,12 @@ safe_strerror (int errnum)
 {
   static thread_local char buf[1024];
 
-  char *msg = nullptr;
-#ifdef HAVE_STRERROR_R
-#  if !__GLIBC__ || ((_POSIX_C_SOURCE >= 200112L) && !  _GNU_SOURCE)
-  /* Glibc has two different, incompatible versions of strerror_r.  */
-  if (strerror_r (errnum, buf, sizeof (buf)) == 0)
-    msg = buf;
-#  else
-  msg = strerror_r (errnum, buf, sizeof (buf));
-#  endif
-#else
-  msg = strerror (errnum);
-#endif
-  if (msg == nullptr)
-    {
-
-      xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
-      msg = buf;
-    }
-  return (msg);
+  /* Assign the return value to an int, so we get an error if we accidentally
+     get the wrong version of this function (glibc has two of them...).  */
+  int ret = strerror_r (errnum, buf, sizeof (buf));
+  if (ret == 0)
+    return buf;
+
+  xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
+  return buf;
 }