xref: /netbsd-src/tests/usr.bin/xlint/lint1/msg_135.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /*	$NetBSD: msg_135.c,v 1.11 2022/07/16 22:36:06 rillig Exp $	*/
2 # 3 "msg_135.c"
3 
4 // Test for message: converting '%s' to '%s' increases alignment from %u to %u [135]
5 
6 /* lint1-extra-flags: -h */
7 
8 void sink(const void *);
9 
10 unsigned
11 read_uint(const unsigned short **pp)
12 {
13 	unsigned val;
14 
15 	/* expect+1: warning: converting 'pointer to const unsigned short' to 'pointer to const unsigned int' increases alignment from 2 to 4 [135] */
16 	val = *(const unsigned *)(*pp);
17 	pp += sizeof(unsigned);
18 	return val;
19 }
20 
21 /* expect+1: warning: struct 'incomplete' never defined [233] */
22 struct incomplete;
23 
24 struct complete {
25     int member;
26 };
27 
28 /*
29  * These types of conversions are typically seen in OpenSSL, when converting
30  * from the publicly visible, incomplete 'struct lhash_st' to a private
31  * implementation type such as 'struct lhash_st_OPENSSL_STRING'.
32  *
33  * Before tree.c 1.277 from 2021-04-17, lint warned about this, even though
34  * there was not enough evidence that there really was an alignment problem,
35  * resulting in many false positives.
36  *
37  * See openssl/lhash.h.
38  */
39 void
40 pointer_to_structs(struct incomplete *incomplete)
41 {
42 	struct complete *complete;
43 
44 	complete = (struct complete *)incomplete;
45 	sink(complete);
46 }
47 
48 /*
49  * Before tree.c 1.316 from 2021-07-15, lint warned about pointer casts from
50  * unsigned char or plain char to another type.  These casts often occur in
51  * traditional code that does not use void pointers, even 30 years after C90
52  * introduced 'void'.
53  */
54 void
55 unsigned_char_to_unsigned_type(unsigned char *ucp)
56 {
57 	unsigned short *usp;
58 
59 	usp = (unsigned short *)ucp;
60 	sink(usp);
61 }
62 
63 /*
64  * Before tree.c 1.316 from 2021-07-15, lint warned about pointer casts from
65  * unsigned char or plain char to another type.  These casts often occur in
66  * traditional code that does not use void pointers, even 30 years after C90
67  * introduced 'void'.
68  */
69 void
70 plain_char_to_unsigned_type(char *cp)
71 {
72 	unsigned short *usp;
73 
74 	usp = (unsigned short *)cp;
75 	sink(usp);
76 }
77