[committed] analyzer: more state machine documentation
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gcc/analyzer/ChangeLog:
* sm-fd.dot: Fix typo in comment.
* sm-file.dot: New file.
* varargs.cc: Fix typo in comment.
* varargs.dot: New file.
Signed-off-by: David Malcolm <dmalcolm@redhat.com>
---
gcc/analyzer/sm-fd.dot | 2 +-
gcc/analyzer/sm-file.dot | 67 ++++++++++++++++++++++++++++++++++++++++
gcc/analyzer/varargs.cc | 2 +-
gcc/analyzer/varargs.dot | 56 +++++++++++++++++++++++++++++++++
4 files changed, 125 insertions(+), 2 deletions(-)
create mode 100644 gcc/analyzer/sm-file.dot
create mode 100644 gcc/analyzer/varargs.dot
@@ -18,7 +18,7 @@ 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 sm-dot.cc */
+/* Keep this in-sync with sm-fd.cc */
digraph "fd" {
new file mode 100644
@@ -0,0 +1,67 @@
+/* An overview of the state machine from sm-file.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 sm-file.cc */
+
+digraph "file" {
+
+ /* STATES. */
+
+ /* Start state. */
+ start;
+
+ /* State for a FILE * returned from fopen that hasn't been checked for
+ NULL.
+ It could be an open stream, or could be NULL. */
+ unchecked;
+
+ /* State for a FILE * that's known to be NULL. */
+ null;
+
+ /* State for a FILE * that's known to be a non-NULL open stream. */
+ nonnull;
+
+ /* State for a FILE * that's had fclose called on it. */
+ closed;
+
+ /* Stop state, for a FILE * we don't want to track any more. */
+ stop;
+
+ /* TRANSITIONS. */
+
+ /* On "fopen". */
+ start -> unchecked [label="on 'X = fopen(...);'"];
+
+ /* On "fclose". */
+ start -> closed [label="on 'close(X);'"];
+ /* TODO: is it safe to call fclose (NULL) ? */
+ unchecked -> closed [label="on 'close(X);'"];
+ null -> closed [label="on 'close(X);'"];
+ nonnull -> closed [label="on 'close(X);'"];
+ closed -> stop [label="on 'close(X);':\nWarn('double fclose')"];
+
+ /* on_condition. */
+ unchecked -> nonnull [label="on 'X != 0'"];
+ unchecked -> null [label="on 'X == 0'"];
+
+ /* Leaks. */
+ unchecked -> stop [label="on leak:\nWarn('leak')"];
+ nonnull -> stop [label="on leak:\nWarn('leak')"];
+}
@@ -216,7 +216,7 @@ public:
}
std::unique_ptr<pending_diagnostic> on_leak (tree var) const final override;
- /* State for a va_list that the result of a va_start or va_copy. */
+ /* State for a va_list that is the result of a va_start or va_copy. */
state_t m_started;
/* State for a va_list that has had va_end called on it. */
new file mode 100644
@@ -0,0 +1,56 @@
+/* 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')"];
+}