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authorJulia Lawall <Julia.Lawall@lip6.fr>2014-08-23 07:34:45 +0200
committerMichal Marek <mmarek@suse.cz>2014-09-26 13:42:31 +0200
commit932058a5d5f9fd919b90aaa2275d54b37340d585 (patch)
treec23f98f5f4d8fd69401db4092fc067336d944b82
parent22739edfc563fa42f02a2f7323fd352061ef32b3 (diff)
coccinelle: misc: semantic patch to delete overly complex return code processing
This semantic patch simplifies cases where the effect of the processing of a function call's return code is just to return the result of the function directly. It may also delete a local return flag variable, if this is no longer used. This was proposed by Uwe Kleine-König. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Michal Marek <mmarek@suse.cz>
-rw-r--r--scripts/coccinelle/misc/simple_return.cocci180
1 files changed, 180 insertions, 0 deletions
diff --git a/scripts/coccinelle/misc/simple_return.cocci b/scripts/coccinelle/misc/simple_return.cocci
new file mode 100644
index 000000000000..47f7084b6360
--- /dev/null
+++ b/scripts/coccinelle/misc/simple_return.cocci
@@ -0,0 +1,180 @@
+/// Simplify a trivial if-return sequence. Possibly combine with a
+/// preceding function call.
+//
+// Confidence: High
+// Copyright: (C) 2014 Julia Lawall, INRIA/LIP6. GPLv2.
+// Copyright: (C) 2014 Gilles Muller, INRIA/LiP6. GPLv2.
+// URL: http://coccinelle.lip6.fr/
+// Comments:
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@r depends on patch@
+local idexpression e;
+identifier i,f,fn;
+@@
+
+fn(...) { <...
+- e@i =
++ return
+ f(...);
+-if (i != 0) return i;
+-return 0;
+...> }
+
+@depends on patch@
+identifier r.i;
+type t;
+@@
+
+-t i;
+ ... when != i
+
+@depends on patch@
+expression e;
+@@
+
+-if (e != 0)
+ return e;
+-return 0;
+
+// -----------------------------------------------------------------------
+
+@s1 depends on context || org || report@
+local idexpression e;
+identifier i,f,fn;
+position p,p1,p2;
+@@
+
+fn(...) { <...
+* e@i@p = f(...);
+ if (\(i@p1 != 0\|i@p2 < 0\))
+ return i;
+ return 0;
+...> }
+
+@s2 depends on context || org || report forall@
+identifier s1.i;
+type t;
+position q,s1.p;
+expression e,f;
+@@
+
+* t i@q;
+ ... when != i
+ e@p = f(...);
+
+@s3 depends on context || org || report@
+expression e;
+position p1!=s1.p1;
+position p2!=s1.p2;
+@@
+
+*if (\(e@p1 != 0\|e@p2 < 0\))
+ return e;
+ return 0;
+
+// -----------------------------------------------------------------------
+
+@script:python depends on org@
+p << s1.p;
+p1 << s1.p1;
+q << s2.q;
+@@
+
+cocci.print_main("decl",q)
+cocci.print_secs("use",p)
+cocci.include_match(False)
+
+@script:python depends on org@
+p << s1.p;
+p2 << s1.p2;
+q << s2.q;
+@@
+
+cocci.print_main("decl",q)
+cocci.print_secs("use with questionable test",p)
+cocci.include_match(False)
+
+@script:python depends on org@
+p << s1.p;
+p1 << s1.p1;
+@@
+
+cocci.print_main("use",p)
+
+@script:python depends on org@
+p << s1.p;
+p2 << s1.p2;
+@@
+
+cocci.print_main("use with questionable test",p)
+
+@script:python depends on org@
+p << s3.p1;
+@@
+
+cocci.print_main("test",p)
+
+@script:python depends on org@
+p << s3.p2;
+@@
+
+cocci.print_main("questionable test",p)
+
+// -----------------------------------------------------------------------
+
+@script:python depends on report@
+p << s1.p;
+p1 << s1.p1;
+q << s2.q;
+@@
+
+msg = "WARNING: end returns can be simpified and declaration on line %s can be dropped" % (q[0].line)
+coccilib.report.print_report(p[0],msg)
+cocci.include_match(False)
+
+@script:python depends on report@
+p << s1.p;
+p1 << s1.p1;
+q << s2.q
+;
+@@
+
+msg = "WARNING: end returns may be simpified if negative or 0 value and declaration on line %s can be dropped" % (q[0].line)
+coccilib.report.print_report(p[0],msg)
+cocci.include_match(False)
+
+@script:python depends on report@
+p << s1.p;
+p1 << s1.p1;
+@@
+
+msg = "WARNING: end returns can be simpified"
+coccilib.report.print_report(p[0],msg)
+
+@script:python depends on report@
+p << s1.p;
+p2 << s1.p2;
+@@
+
+msg = "WARNING: end returns can be simpified if negative or 0 value"
+coccilib.report.print_report(p[0],msg)
+
+@script:python depends on report@
+p << s3.p1;
+@@
+
+msg = "WARNING: end returns can be simpified"
+coccilib.report.print_report(p[0],msg)
+
+@script:python depends on report@
+p << s3.p2;
+@@
+
+msg = "WARNING: end returns can be simpified if tested value is negative or 0"
+coccilib.report.print_report(p[0],msg)