[PATCH] GDB friendly assert

[Mark Kettenis <kettenis at wins dot uva dot nl>]

FYI, I have checked in a GDB-friendly replacement for <assert.h>.  So
now you can use assertions all over your code without unconditionally
crashing GDB when an assertion is tripped.  Simply use gdb_assert()
where you traditionally assert().  It calls internal_error(), so the
user gets the option of exiting GDB (with or without core dump) or
continuing the session.

Since gdb_assert() is modelled after the glibc assert(), it also
prints the name of the function that contains the assertion if GDB was
compiled with GCC or an ISO C99 compiler.

I think I addressed the objections that Andrew had with the proposal I
posted some time ago (I changed the name into gdb_assert() and
assert_perror() is gone, it isn't useful for GDB).

Mark


2000-09-03  Mark Kettenis  <kettenis@gnu.org>

	* gdb_assert.h: New file.


--- /dev/null	Thu Feb 19 16:30:24 1998
+++ gdb_assert.h	Sat Sep  2 15:19:13 2000
@@ -0,0 +1,51 @@
+/* GDB-friendly replacement for <assert.h>.
+   Copyright 2000 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef GDB_ASSERT_H
+#define GDB_ASSERT_H
+
+#define gdb_assert(expr)                                                      \
+  ((void) ((expr) ? 0 :                                                       \
+	   (gdb_assert_fail (#expr, __FILE__, __LINE__, ASSERT_FUNCTION), 0)))
+
+/* Version 2.4 and later of GCC define a magical variable `__PRETTY_FUNCTION__'
+   which contains the name of the function currently being defined.
+   This is broken in G++ before version 2.6.
+   C9x has a similar variable called __func__, but prefer the GCC one since
+   it demangles C++ function names.  */
+#if (GCC_VERSION >= 2004)
+#define ASSERT_FUNCTION		__PRETTY_FUNCTION__
+#else
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+#define ASSERT_FUNCTION		__func__
+#else
+#define ASSERT_FUNCTION		((const char *) 0)
+#endif
+#endif
+
+/* This prints an "Assertion failed" message, aksing the user if they
+   want to continue, dump core, or just exit.  */
+#define gdb_assert_fail(assertion, file, line, function)                      \
+  internal_error ("%s:%u: %s%sAssertion `%s' failed.",                        \
+		  file, line,                                                 \
+		  function ? function : "", function ? ": " : "",             \
+		  assertion)
+
+#endif /* gdb_assert.h */