xref: /linux/tools/lib/subcmd/subcmd-util.h (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __SUBCMD_UTIL_H
3 #define __SUBCMD_UTIL_H
4 
5 #include <stdarg.h>
6 #include <stdlib.h>
7 #include <stdio.h>
8 #include <linux/compiler.h>
9 
10 static inline void report(const char *prefix, const char *err, va_list params)
11 {
12 	char msg[1024];
13 	vsnprintf(msg, sizeof(msg), err, params);
14 	fprintf(stderr, " %s%s\n", prefix, msg);
15 }
16 
17 static __noreturn inline void die(const char *err, ...)
18 {
19 	va_list params;
20 
21 	va_start(params, err);
22 	report(" Fatal: ", err, params);
23 	exit(128);
24 	va_end(params);
25 }
26 
27 #define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
28 
29 #define alloc_nr(x) (((x)+16)*3/2)
30 
31 /*
32  * Realloc the buffer pointed at by variable 'x' so that it can hold
33  * at least 'nr' entries; the number of entries currently allocated
34  * is 'alloc', using the standard growing factor alloc_nr() macro.
35  *
36  * DO NOT USE any expression with side-effect for 'x' or 'alloc'.
37  */
38 #define ALLOC_GROW(x, nr, alloc) \
39 	do { \
40 		if ((nr) > alloc) { \
41 			if (alloc_nr(alloc) < (nr)) \
42 				alloc = (nr); \
43 			else \
44 				alloc = alloc_nr(alloc); \
45 			x = xrealloc((x), alloc * sizeof(*(x))); \
46 		} \
47 	} while(0)
48 
49 static inline void *xrealloc(void *ptr, size_t size)
50 {
51 	void *ret = realloc(ptr, size);
52 	if (!ret)
53 		die("Out of memory, realloc failed");
54 	return ret;
55 }
56 
57 #define astrcatf(out, fmt, ...)						\
58 ({									\
59 	char *tmp = *(out);						\
60 	if (asprintf((out), "%s" fmt, tmp ?: "", ## __VA_ARGS__) == -1)	\
61 		die("asprintf failed");					\
62 	free(tmp);							\
63 })
64 
65 static inline void astrcat(char **out, const char *add)
66 {
67 	char *tmp = *out;
68 
69 	if (asprintf(out, "%s%s", tmp ?: "", add) == -1)
70 		die("asprintf failed");
71 
72 	free(tmp);
73 }
74 
75 #endif /* __SUBCMD_UTIL_H */
76