[Cocci] [coccicheck PATCH 2/5] Deletion of unnecessary checks before specific function calls

SF Markus Elfring elfring at users.sourceforge.net
Wed Oct 1 16:06:45 CEST 2014


>>> If you are convinced that dropping the null tests is a good idea, then you 
>>> can submit the patch that makes the change to the relevant maintainers and 
>>> mailing lists.

>From 1d2de3c3cfa43cc3c78a91200c41cef438b26a8f Mon Sep 17 00:00:00 2001
From: Markus Elfring <elfring at users.sourceforge.net>
Date: Wed, 5 Mar 2014 18:38:43 +0100
Subject: [PATCH 2/5] Addition of a semantic patch file for listing of
 functions that check their single parameter

This semantic patch pattern tries to find functions that check their single
parameter for usability.

Example:
Null pointer checks are often performed as input parameter validation.

It uses Python statements to write information about the found source code
places in a data format that is a variant of a CSV text file.

Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 .../list_input_parameter_validation1.cocci         | 55 ++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644
scripts/coccinelle/deletions/list_input_parameter_validation1.cocci

diff --git a/scripts/coccinelle/deletions/list_input_parameter_validation1.cocci
b/scripts/coccinelle/deletions/list_input_parameter_validation1.cocci
new file mode 100644
index 0000000..b0a5a52
--- /dev/null
+++ b/scripts/coccinelle/deletions/list_input_parameter_validation1.cocci
@@ -0,0 +1,55 @@
+ at initialize:python@
+@@
+import sys
+result = []
+mark = ['"', '', '"']
+delimiter = '|'
+
+def store_positions(fun, typ, point, places):
+    """Add source code positions to an internal list."""
+    for place in places:
+        fields = []
+        fields.append(fun)
+
+        mark[1] = typ
+        fields.append(''.join(mark))
+
+        fields.append(point)
+
+        mark[1] = place.file.replace('"', '""')
+        fields.append(''.join(mark))
+
+        fields.append(place.line)
+        fields.append(str(int(place.column) + 1))
+        result.append(delimiter.join(fields))
+
+ at safety_check@
+identifier work, input;
+type data_type;
+position pos;
+statement is, es;
+@@
+ void work at pos(data_type input)
+ {
+  ... when any
+( if (input) is else es
+| if (likely(input)) is else es
+)
+  ... when any
+ }
+
+ at script:python collection depends on safety_check@
+typ << safety_check.data_type;
+fun << safety_check.work;
+point << safety_check.input;
+places << safety_check.pos;
+@@
+store_positions(fun, typ, point, places)
+
+ at finalize:python@
+@@
+if result:
+   result.insert(0, delimiter.join(("function", '"data type"', '"parameter"',
'"source file"', "line", "column")))
+   print("\r\n".join(result))
+else:
+   sys.stderr.write("No result for this analysis!\n")
-- 
1.9.0




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