gcc/analyzer/varargs.dot

/* An overview of the state machine from varargs.cc
   Copyright (C) 2022 Free Software Foundation, Inc.
   Contributed by David Malcolm <dmalcolm@redhat.com>.

This file is part of GCC.

GCC 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 3, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

/* Keep this in-sync with varargs.cc  */

digraph "va_list" {

  /* STATES. */

  /* Start state.  */
  start;

  /* State for a va_list that is the result of a va_start or va_copy.  */
  started;

  /* State for a va_list that has had va_end called on it.  */
  ended;

  /* TRANSITIONS. */

  /* on_va_start: */
  start -> started [label="on 'va_start(X, ...)'"];

  /* on_va_copy: */
  start -> started [label="on 'va_copy(X, ...)'"];
  // in check_for_ended_va_list:
  ended -> ended [label="on 'va_copy(X, ...)':\nWarn('use after va_end')"];

  /* on_va_arg: */
  started -> started [label="on 'va_arg(X, ...)'"];
  started -> started [label="on 'va_copy(..., X)'"];
  // in check_for_ended_va_list:
  ended -> ended [label="on 'va_arg(X, ...)':\nWarn('use after va_end')"];

  /* on_va_end: */
  started -> ended [label="on 'va_end(X)'"];
  // in check_for_ended_va_list:
  ended -> ended [label="on 'va_end(X)':\nWarn('use after va_end')"];
}