make gdbserver use the same ptrace autoconf checks as gdb

This factors the ptrace checks out of gdb's configure.ac to a new
ptrace.m4 file, and then makes gdbserver's configure.ac source it too.

gdb/ChangeLog:
2015-07-24  Pedro Alves  <palves@redhat.com>

	* acinclude.m4: Include ptrace.m4.
	* configure.ac: Call GDB_AC_PTRACE and move ptrace checks ...
	* ptrace.m4: ... to this new file.

gdb/gdbserver/ChangeLog:
2015-07-24  Pedro Alves  <palves@redhat.com>

	* acinclude.m4: Include ../ptrace.m4.
	* configure.ac: Call GDB_AC_PTRACE.
	* config.in, configure: Regenerate.

1 files changed, 92 insertions, 0 deletions

diff --git a/gdb/ptrace.m4 b/gdb/ptrace.m4
new file mode 100644
index 00000000000..e5fe7fa9660
--- /dev/null
+++ b/gdb/ptrace.m4
@@ -0,0 +1,92 @@
+dnl Copyright (C) 2012-2015 Free Software Foundation, Inc.
+dnl
+dnl This file is part of GDB.
+dnl
+dnl This program is free software; you can redistribute it and/or modify
+dnl it under the terms of the GNU General Public License as published by
+dnl the Free Software Foundation; either version 3 of the License, or
+dnl (at your option) any later version.
+dnl
+dnl This program is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+dnl GNU General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+dnl Check the return and argument types of ptrace.
+
+AC_DEFUN([GDB_AC_PTRACE],
+[
+
+AC_CHECK_HEADERS([sys/ptrace.h ptrace.h])
+
+gdb_ptrace_headers='
+#include <sys/types.h>
+#if HAVE_SYS_PTRACE_H
+# include <sys/ptrace.h>
+#endif
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+'
+# There is no point in checking if we don't have a prototype.
+AC_CHECK_DECLS(ptrace, [], [
+  : ${gdb_cv_func_ptrace_ret='int'}
+  : ${gdb_cv_func_ptrace_args='int,int,long,long'}
+], $gdb_ptrace_headers)
+# Check return type.  Varargs (used on GNU/Linux) conflict with the
+# empty argument list, so check for that explicitly.
+AC_CACHE_CHECK([return type of ptrace], gdb_cv_func_ptrace_ret,
+  AC_TRY_COMPILE($gdb_ptrace_headers,
+    [extern long ptrace (enum __ptrace_request, ...);],
+    gdb_cv_func_ptrace_ret='long',
+    AC_TRY_COMPILE($gdb_ptrace_headers,
+      [extern int ptrace ();],
+      gdb_cv_func_ptrace_ret='int',
+      gdb_cv_func_ptrace_ret='long')))
+AC_DEFINE_UNQUOTED(PTRACE_TYPE_RET, $gdb_cv_func_ptrace_ret,
+  [Define as the return type of ptrace.])
+# Check argument types.
+AC_CACHE_CHECK([types of arguments for ptrace], gdb_cv_func_ptrace_args, [
+  AC_TRY_COMPILE($gdb_ptrace_headers,
+    [extern long ptrace (enum __ptrace_request, ...);],
+    [gdb_cv_func_ptrace_args='int,int,long,long'],[
+for gdb_arg1 in 'int' 'long'; do
+ for gdb_arg2 in 'pid_t' 'int' 'long'; do
+  for gdb_arg3 in 'int *' 'caddr_t' 'int' 'long' 'void *'; do
+   for gdb_arg4 in 'int' 'long' 'void *'; do
+     AC_TRY_COMPILE($gdb_ptrace_headers, [
+extern $gdb_cv_func_ptrace_ret
+  ptrace ($gdb_arg1, $gdb_arg2, $gdb_arg3, $gdb_arg4);
+], [gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4";
+    break 4;])
+    for gdb_arg5 in 'int *' 'int' 'long'; do
+     AC_TRY_COMPILE($gdb_ptrace_headers, [
+extern $gdb_cv_func_ptrace_ret
+  ptrace ($gdb_arg1, $gdb_arg2, $gdb_arg3, $gdb_arg4, $gdb_arg5);
+], [
+gdb_cv_func_ptrace_args="$gdb_arg1,$gdb_arg2,$gdb_arg3,$gdb_arg4,$gdb_arg5";
+    break 5;])
+    done
+   done
+  done
+ done
+done
+# Provide a safe default value.
+: ${gdb_cv_func_ptrace_args='int,int,long,long'}
+])])
+ac_save_IFS=$IFS; IFS=','
+set dummy `echo "$gdb_cv_func_ptrace_args" | sed 's/\*/\*/g'`
+IFS=$ac_save_IFS
+shift
+AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG3, $[3],
+  [Define to the type of arg 3 for ptrace.])
+AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG4, $[4],
+  [Define to the type of arg 4 for ptrace.])
+if test -n "$[5]"; then
+  AC_DEFINE_UNQUOTED(PTRACE_TYPE_ARG5, $[5],
+    [Define to the type of arg 5 for ptrace.])
+fi
+])