xref: /linux/scripts/coccinelle/misc/minmax.cocci (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
1// SPDX-License-Identifier: GPL-2.0-only
2///
3/// Check for opencoded min(), max() implementations.
4/// Generated patches sometimes require adding a cast to fix compile warning.
5/// Warnings/patches scope intentionally limited to a function body.
6///
7// Confidence: Medium
8// Copyright: (C) 2021 Denis Efremov ISPRAS
9// Options: --no-includes --include-headers
10//
11// Keywords: min, max
12//
13
14
15virtual report
16virtual org
17virtual context
18virtual patch
19
20@rmax depends on !patch@
21identifier func;
22expression x, y;
23binary operator cmp = {>, >=};
24position p;
25@@
26
27func(...)
28{
29	<...
30*	((x) cmp@p (y) ? (x) : (y))
31	...>
32}
33
34@rmaxif depends on !patch@
35identifier func;
36expression x, y;
37expression max_val;
38binary operator cmp = {>, >=};
39position p;
40@@
41
42func(...)
43{
44	<...
45*	if ((x) cmp@p (y)) {
46*		max_val = (x);
47*	} else {
48*		max_val = (y);
49*	}
50	...>
51}
52
53@rmin depends on !patch@
54identifier func;
55expression x, y;
56binary operator cmp = {<, <=};
57position p;
58@@
59
60func(...)
61{
62	<...
63*	((x) cmp@p (y) ? (x) : (y))
64	...>
65}
66
67@rminif depends on !patch@
68identifier func;
69expression x, y;
70expression min_val;
71binary operator cmp = {<, <=};
72position p;
73@@
74
75func(...)
76{
77	<...
78*	if ((x) cmp@p (y)) {
79*		min_val = (x);
80*	} else {
81*		min_val = (y);
82*	}
83	...>
84}
85
86@pmax depends on patch@
87identifier func;
88expression x, y;
89binary operator cmp = {>=, >};
90@@
91
92func(...)
93{
94	<...
95-	((x) cmp (y) ? (x) : (y))
96+	max(x, y)
97	...>
98}
99
100@pmaxif depends on patch@
101identifier func;
102expression x, y;
103expression max_val;
104binary operator cmp = {>=, >};
105@@
106
107func(...)
108{
109	<...
110-	if ((x) cmp (y)) {
111-		max_val = x;
112-	} else {
113-		max_val = y;
114-	}
115+	max_val = max(x, y);
116	...>
117}
118
119// Don't generate patches for errcode returns.
120@errcode depends on patch@
121position p;
122identifier func;
123expression x;
124binary operator cmp = {<, <=};
125@@
126
127func(...)
128{
129	<...
130	return ((x) cmp@p 0 ? (x) : 0);
131	...>
132}
133
134@pmin depends on patch@
135identifier func;
136expression x, y;
137binary operator cmp = {<=, <};
138position p != errcode.p;
139@@
140
141func(...)
142{
143	<...
144-	((x) cmp@p (y) ? (x) : (y))
145+	min(x, y)
146	...>
147}
148
149@pminif depends on patch@
150identifier func;
151expression x, y;
152expression min_val;
153binary operator cmp = {<=, <};
154@@
155
156func(...)
157{
158	<...
159-	if ((x) cmp (y)) {
160-		min_val = x;
161-	} else {
162-		min_val = y;
163-	}
164+	min_val = min(x, y);
165	...>
166}
167
168@script:python depends on report@
169p << rmax.p;
170@@
171
172for p0 in p:
173	coccilib.report.print_report(p0, "WARNING opportunity for max()")
174
175@script:python depends on org@
176p << rmax.p;
177@@
178
179for p0 in p:
180	coccilib.org.print_todo(p0, "WARNING opportunity for max()")
181
182@script:python depends on report@
183p << rmaxif.p;
184@@
185
186for p0 in p:
187	coccilib.report.print_report(p0, "WARNING opportunity for max()")
188
189@script:python depends on org@
190p << rmaxif.p;
191@@
192
193for p0 in p:
194	coccilib.org.print_todo(p0, "WARNING opportunity for max()")
195
196@script:python depends on report@
197p << rmin.p;
198@@
199
200for p0 in p:
201	coccilib.report.print_report(p0, "WARNING opportunity for min()")
202
203@script:python depends on org@
204p << rmin.p;
205@@
206
207for p0 in p:
208	coccilib.org.print_todo(p0, "WARNING opportunity for min()")
209
210@script:python depends on report@
211p << rminif.p;
212@@
213
214for p0 in p:
215	coccilib.report.print_report(p0, "WARNING opportunity for min()")
216
217@script:python depends on org@
218p << rminif.p;
219@@
220
221for p0 in p:
222	coccilib.org.print_todo(p0, "WARNING opportunity for min()")
223