Properly handle invalid input

See https://savannah.gnu.org/bugs/?44113

* src/parser.c (cleanup_stack): Ignore negative deltas.
(parse_function_declaration): Don't set caller if the symbol
is in automatic storage. Note: that means nested function definitions
can't be handled.
* tests/invalid.at: New test case.
* tests/Makefile.am: Add new test case.
* tests/testsuite.at: Likewise.

5 files changed, 42 insertions, 2 deletions

diff --git a/.gitignore b/.gitignore
index 60d871e..9039854 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,2 +15,3 @@ ChangeLog
 INSTALL
+TAGS
 Makefile
diff --git a/src/parser.c b/src/parser.c
index 4126145..4be9d4e 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -276,5 +276,6 @@ cleanup_stack()
 
-     if (delta) 
+     if (delta > 0) 
 	  memmove(token_stack, token_stack+curs, delta*sizeof(token_stack[0]));
-
+     else if (delta < 0) /* Invalid input */
+	  delta = 0;
      tos = delta;
@@ -654,2 +655,4 @@ parse_function_declaration(Ident *ident, int parm)
 	       caller = lookup(ident->name);
+	       if (caller && caller->storage == AutoStorage)
+		    caller = NULL;
 	       func_body();
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 5f7d77c..4173c5f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -50,2 +50,3 @@ TESTSUITE_AT = \
  include.at\
+ invalid.at\
  knr.at\
diff --git a/tests/invalid.at b/tests/invalid.at
new file mode 100644
index 0000000..581f8eb
--- /dev/null
+++ b/tests/invalid.at
@@ -0,0 +1,34 @@
+# This file is part of GNU cflow testsuite. -*- Autotest -*-
+# Copyright (C) 2016 Sergey Poznyakoff
+#
+# 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 3, 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, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([invalid input])
+AT_KEYWORDS([invalid])
+
+# See https://savannah.gnu.org/bugs/?44113
+CFLOW_CHECK([
+m{int
+r(a(n){}e 
+])
+
+CFLOW_CHECK([
+e(S,t)e(S{ 
+])
+
+CFLOW_CHECK([
+n{void y(r(i){}a
+])
+
+AT_CLEANUP
diff --git a/tests/testsuite.at b/tests/testsuite.at
index e516a78..7ed3d7a 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -73,2 +73,3 @@ m4_include([struct04.at])
 m4_include([decl01.at])
+m4_include([invalid.at])