scripts/coccinelle: add some more coccinelle tests

kmerr: verify that malloc and calloc are followed by a check to verify
that we are not out of memory.

badzero: Compare pointer-typed values to NULL rather than 0

Both checks are copied from the Linux kernel archive.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

scripts/coccinelle/null/badzero.cocci

@@ -0,0 +1,241 @@
+/// Compare pointer-typed values to NULL rather than 0
+///
+//# This makes an effort to choose between !x and x == NULL.  !x is used
+//# if it has previously been used with the function used to initialize x.
+//# This relies on type information.  More type information can be obtained
+//# using the option -all_includes and the option -I to specify an
+//# include path.
+//
+// Confidence: High
+// Copyright: (C) 2012 Julia Lawall, INRIA/LIP6.  GPLv2.
+// Copyright: (C) 2012 Gilles Muller, INRIA/LiP6.  GPLv2.
+// URL: http://coccinelle.lip6.fr/
+// Requires: 1.0.0
+// Options:
+//
+// SPDX-License-Identifier:	GPL-2.0
+//
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@initialize:ocaml@
+@@
+let negtable = Hashtbl.create 101
+
+@depends on patch@
+expression *E;
+identifier f;
+@@
+
+(
+  (E = f(...)) ==
+- 0
++ NULL
+|
+  (E = f(...)) !=
+- 0
++ NULL
+|
+- 0
++ NULL
+  == (E = f(...))
+|
+- 0
++ NULL
+  != (E = f(...))
+)
+
+
+@t1 depends on !patch@
+expression *E;
+identifier f;
+position p;
+@@
+
+(
+  (E = f(...)) ==
+* 0@p
+|
+  (E = f(...)) !=
+* 0@p
+|
+* 0@p
+  == (E = f(...))
+|
+* 0@p
+  != (E = f(...))
+)
+
+@script:python depends on org@
+p << t1.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
+
+@script:python depends on report@
+p << t1.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
+
+// Tests of returned values
+
+@s@
+identifier f;
+expression E,E1;
+@@
+
+ E = f(...)
+ ... when != E = E1
+ !E
+
+@script:ocaml depends on s@
+f << s.f;
+@@
+
+try let _ = Hashtbl.find negtable f in ()
+with Not_found -> Hashtbl.add negtable f ()
+
+@ r disable is_zero,isnt_zero exists @
+expression *E;
+identifier f;
+@@
+
+E = f(...)
+...
+(E == 0
+|E != 0
+|0 == E
+|0 != E
+)
+
+@script:ocaml@
+f << r.f;
+@@
+
+try let _ = Hashtbl.find negtable f in ()
+with Not_found -> include_match false
+
+// This rule may lead to inconsistent path problems, if E is defined in two
+// places
+@ depends on patch disable is_zero,isnt_zero @
+expression *E;
+expression E1;
+identifier r.f;
+@@
+
+E = f(...)
+<...
+(
+- E == 0
++ !E
+|
+- E != 0
++ E
+|
+- 0 == E
++ !E
+|
+- 0 != E
++ E
+)
+...>
+?E = E1
+
+@t2 depends on !patch disable is_zero,isnt_zero @
+expression *E;
+expression E1;
+identifier r.f;
+position p1;
+position p2;
+@@
+
+E = f(...)
+<...
+(
+* E == 0@p1
+|
+* E != 0@p2
+|
+* 0@p1 == E
+|
+* 0@p1 != E
+)
+...>
+?E = E1
+
+@script:python depends on org@
+p << t2.p1;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0, suggest !E")
+
+@script:python depends on org@
+p << t2.p2;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
+
+@script:python depends on report@
+p << t2.p1;
+@@
+
+coccilib.report.print_report(p[0], "WARNING comparing pointer to 0, suggest !E")
+
+@script:python depends on report@
+p << t2.p2;
+@@
+
+coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")
+
+@ depends on patch disable is_zero,isnt_zero @
+expression *E;
+@@
+
+(
+  E ==
+- 0
++ NULL
+|
+  E !=
+- 0
++ NULL
+|
+- 0
++ NULL
+  == E
+|
+- 0
++ NULL
+  != E
+)
+
+@ t3 depends on !patch disable is_zero,isnt_zero @
+expression *E;
+position p;
+@@
+
+(
+* E == 0@p
+|
+* E != 0@p
+|
+* 0@p == E
+|
+* 0@p != E
+)
+
+@script:python depends on org@
+p << t3.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING comparing pointer to 0")
+
+@script:python depends on report@
+p << t3.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING comparing pointer to 0")

scripts/coccinelle/null/kmerr.cocci

@@ -0,0 +1,75 @@
+/// This semantic patch looks for malloc etc that are not followed by a
+/// NULL check.  It only gives a report in the case where there is some
+/// error handling code later in the function, which may be helpful
+/// in determining what the error handling code for the call to malloc etc
+/// should be.
+///
+// Confidence: High
+// Copyright: (C) 2010 Nicolas Palix, DIKU.  GPLv2.
+// Copyright: (C) 2010 Julia Lawall, DIKU.  GPLv2.
+// Copyright: (C) 2010 Gilles Muller, INRIA/LiP6.  GPLv2.
+// URL: http://coccinelle.lip6.fr/
+// Comments:
+// Options: --no-includes --include-headers
+//
+// SPDX-License-Identifier:	GPL-2.0
+//
+
+virtual context
+virtual org
+virtual report
+
+@withtest@
+expression x;
+position p;
+identifier f,fld;
+@@
+
+x@p = f(...);
+... when != x->fld
+\(x == NULL \| x != NULL\)
+
+@fixed depends on context && !org && !report@
+expression x,x1;
+position p1 != withtest.p;
+statement S;
+position any withtest.p;
+identifier f;
+@@
+
+*x@p1 = \(malloc\|calloc\)(...);
+...
+*x1@p = f(...);
+if (!x1) S
+
+// ------------------------------------------------------------------------
+
+@rfixed depends on (org || report) && !context exists@
+expression x,x1;
+position p1 != withtest.p;
+position p2;
+statement S;
+position any withtest.p;
+identifier f;
+@@
+
+x@p1 = \(malloc\|calloc\)(...);
+...
+x1@p = f@p2(...);
+if (!x1) S
+
+@script:python depends on org@
+p1 << rfixed.p1;
+p2 << rfixed.p2;
+@@
+
+cocci.print_main("alloc call",p1)
+cocci.print_secs("possible model",p2)
+
+@script:python depends on report@
+p1 << rfixed.p1;
+p2 << rfixed.p2;
+@@
+
+msg = "alloc with no test, possible model on line %s" % (p2[0].line)
+coccilib.report.print_report(p1[0],msg)