[PATCH] gdb: remove HAVE_DECL_PTRACE

[Simon Marchi <simon.marchi@efficios.com>]

I stumbled on this snippet in nat/gdb_ptrace.h:

    /* Some systems, in particular DEC OSF/1, Digital Unix, Compaq Tru64
       or whatever it's called these days, don't provide a prototype for
       ptrace.  Provide one to silence compiler warnings.  */

    #ifndef HAVE_DECL_PTRACE
    extern PTRACE_TYPE_RET ptrace();
    #endif

I believe this is unnecessary today and should be removed.  First, the
comment only mentions OSes we don't support (and to be honest, I had
never even heard of).

But most importantly, in C++, a declaration with empty parenthesis
declares a function that accepts no arguments, unlike in C.  So if this
declaration was really used, GDB wouldn't build, since all ptrace call
sites pass some arguments.  Since we haven't heard anything about this
causing some build failures since we have transitioned to C++, I
conclude that it's not used.

This patch removes it as well as the corresponding configure check.

gdb/ChangeLog:

	* ptrace.m4: Don't check for ptrace declaration.
	* config.in: Re-generate.
	* configure: Re-generate.
	* nat/gdb_ptrace.h: Don't declare ptrace if HAVE_DECL_PTRACE is
	not defined.

gdbserver/ChangeLog:

	* config.in: Re-generate.
	* configure: Re-generate.

gdbsupport/ChangeLog:

	* config.in: Re-generate.
	* configure: Re-generate.
---
 gdb/config.in        |  4 ----
 gdb/configure        | 20 --------------------
 gdb/nat/gdb_ptrace.h |  8 --------
 gdb/ptrace.m4        |  6 +-----
 gdbserver/config.in  |  4 ----
 gdbserver/configure  | 20 --------------------
 gdbsupport/config.in |  4 ----
 gdbsupport/configure | 20 --------------------
 8 files changed, 1 insertion(+), 85 deletions(-)

diff --git a/gdb/config.in b/gdb/config.in
index 7a34b85e5754..118e424580e5 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -109,10 +109,6 @@
    don't. */
 #undef HAVE_DECL_GETTHRDS
 
-/* Define to 1 if you have the declaration of `ptrace', and to 0 if you don't.
-   */
-#undef HAVE_DECL_PTRACE
-
 /* Define to 1 if you have the declaration of `snprintf', and to 0 if you
    don't. */
 #undef HAVE_DECL_SNPRINTF
diff --git a/gdb/configure b/gdb/configure
index 614f3402c3d6..afafc2c8d181 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -15000,26 +15000,6 @@ gdb_ptrace_headers='
 # include <unistd.h>
 #endif
 '
-# There is no point in checking if we don't have a prototype.
-ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers
-"
-if test "x$ac_cv_have_decl_ptrace" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_PTRACE $ac_have_decl
-_ACEOF
-if test $ac_have_decl = 1; then :
-
-else
-
-  : ${gdb_cv_func_ptrace_ret='int'}
-  : ${gdb_cv_func_ptrace_args='int,int,long,long'}
-
-fi
 
 # Check return type.  Varargs (used on GNU/Linux) conflict with the
 # empty argument list, so check for that explicitly.
diff --git a/gdb/nat/gdb_ptrace.h b/gdb/nat/gdb_ptrace.h
index 9c2587f2e822..1278246559c0 100644
--- a/gdb/nat/gdb_ptrace.h
+++ b/gdb/nat/gdb_ptrace.h
@@ -121,14 +121,6 @@
 # endif
 #endif
 
-/* Some systems, in particular DEC OSF/1, Digital Unix, Compaq Tru64
-   or whatever it's called these days, don't provide a prototype for
-   ptrace.  Provide one to silence compiler warnings.  */
-
-#ifndef HAVE_DECL_PTRACE
-extern PTRACE_TYPE_RET ptrace();
-#endif
-
 /* Some systems, at least AIX and HP-UX have a ptrace with five
    arguments.  Since we never use the fifth argument, define a ptrace
    macro that calls the real ptrace with the last argument set to
diff --git a/gdb/ptrace.m4 b/gdb/ptrace.m4
index 4cd7652718a9..0fcd855aa8fd 100644
--- a/gdb/ptrace.m4
+++ b/gdb/ptrace.m4
@@ -31,11 +31,7 @@ gdb_ptrace_headers='
 # 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,
diff --git a/gdbserver/config.in b/gdbserver/config.in
index e62795072f20..da1bdbe3d946 100644
--- a/gdbserver/config.in
+++ b/gdbserver/config.in
@@ -50,10 +50,6 @@
    */
 #undef HAVE_DECL_PERROR
 
-/* Define to 1 if you have the declaration of `ptrace', and to 0 if you don't.
-   */
-#undef HAVE_DECL_PTRACE
-
 /* Define to 1 if you have the declaration of `snprintf', and to 0 if you
    don't. */
 #undef HAVE_DECL_SNPRINTF
diff --git a/gdbserver/configure b/gdbserver/configure
index 55cf2416b568..0de11f7ee619 100755
--- a/gdbserver/configure
+++ b/gdbserver/configure
@@ -9413,26 +9413,6 @@ gdb_ptrace_headers='
 # include <unistd.h>
 #endif
 '
-# There is no point in checking if we don't have a prototype.
-ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers
-"
-if test "x$ac_cv_have_decl_ptrace" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_PTRACE $ac_have_decl
-_ACEOF
-if test $ac_have_decl = 1; then :
-
-else
-
-  : ${gdb_cv_func_ptrace_ret='int'}
-  : ${gdb_cv_func_ptrace_args='int,int,long,long'}
-
-fi
 
 # Check return type.  Varargs (used on GNU/Linux) conflict with the
 # empty argument list, so check for that explicitly.
diff --git a/gdbsupport/config.in b/gdbsupport/config.in
index 6a6b0bc74f09..94e90ecc5451 100644
--- a/gdbsupport/config.in
+++ b/gdbsupport/config.in
@@ -43,10 +43,6 @@
 /* Define to 1 if you have the declaration of `ffs', and to 0 if you don't. */
 #undef HAVE_DECL_FFS
 
-/* Define to 1 if you have the declaration of `ptrace', and to 0 if you don't.
-   */
-#undef HAVE_DECL_PTRACE
-
 /* Define to 1 if you have the declaration of `snprintf', and to 0 if you
    don't. */
 #undef HAVE_DECL_SNPRINTF
diff --git a/gdbsupport/configure b/gdbsupport/configure
index 2ffe539eb092..186cac6d5745 100755
--- a/gdbsupport/configure
+++ b/gdbsupport/configure
@@ -10666,26 +10666,6 @@ gdb_ptrace_headers='
 # include <unistd.h>
 #endif
 '
-# There is no point in checking if we don't have a prototype.
-ac_fn_c_check_decl "$LINENO" "ptrace" "ac_cv_have_decl_ptrace" "$gdb_ptrace_headers
-"
-if test "x$ac_cv_have_decl_ptrace" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_PTRACE $ac_have_decl
-_ACEOF
-if test $ac_have_decl = 1; then :
-
-else
-
-  : ${gdb_cv_func_ptrace_ret='int'}
-  : ${gdb_cv_func_ptrace_args='int,int,long,long'}
-
-fi
 
 # Check return type.  Varargs (used on GNU/Linux) conflict with the
 # empty argument list, so check for that explicitly.
-- 
2.25.1