lkml.org 
[lkml]   [2013]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] coccinelle: Add a script to find and remove unnecessary ifs with no body
This script matches code like:

if (foo) {}

and either eliminates it (if foo has no side effects) or replaces it
with foo (if foo has side effects).

Works perfectly in report mode; the results of patch mode are
semantically correct but may still benefit from further simplification.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
---
scripts/coccinelle/misc/unnecessary-if.cocci | 40 ++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
create mode 100644 scripts/coccinelle/misc/unnecessary-if.cocci

diff --git a/scripts/coccinelle/misc/unnecessary-if.cocci b/scripts/coccinelle/misc/unnecessary-if.cocci
new file mode 100644
index 0000000..7ed721f
--- /dev/null
+++ b/scripts/coccinelle/misc/unnecessary-if.cocci
@@ -0,0 +1,40 @@
+/// Remove unnecessary ifs with no statements.
+//
+// Confidence: High
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual report
+virtual context
+
+@r1 depends on patch@
+expression E, E2, f;
+@@
+(
+- if (
+ <+... \(f(...)\|++E\|--E\|E++\|E--\|E=E2\) ...+>
+- ) {}
++ ;
+|
+- if (E) {}
+)
+
+@r2 depends on report || context@
+expression E, E2, f;
+position p;
+@@
+(
+- if@p (
+ <+... \(f(...)\|++E\|--E\|E++\|E--\|E=E2\) ...+>
+- ) {}
++ ;
+|
+- if@p (E) {}
+)
+
+@script:python depends on report@
+p << r2.p;
+@@
+
+msg = "WARNING: Unnecessary if with no body."
+coccilib.report.print_report(p[0], msg)
--
1.8.4.2


\
 
 \ /
  Last update: 2013-11-02 15:41    [W:0.509 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site