coccinelle: replace 0/1 with false/true in functions returning bool

This semantic patch replaces "return {0,1};" with "return
{false,true};" in functions returning bool.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/coccinelle/misc/boolreturn.cocci

@@ -0,0 +1,58 @@
+/// Return statements in functions returning bool should use
+/// true/false instead of 1/0.
+//
+// Confidence: High
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual report
+virtual context
+
+@r1 depends on patch@
+identifier fn;
+typedef bool;
+symbol false;
+symbol true;
+@@
+
+bool fn ( ... )
+{
+<...
+return
+(
+- 0
++ false
+|
+- 1
++ true
+)
+  ;
+...>
+}
+
+@r2 depends on report || context@
+identifier fn;
+position p;
+@@
+
+bool fn ( ... )
+{
+<...
+return
+(
+* 0@p
+|
+* 1@p
+)
+  ;
+...>
+}
+
+
+@script:python depends on report@
+p << r2.p;
+fn << r2.fn;
+@@
+
+msg = "WARNING: return of 0/1 in function '%s' with return type bool" % fn
+coccilib.report.print_report(p[0], msg)