xref: /linux/tools/lib/subcmd/subcmd-util.h (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
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 
9 #define NORETURN __attribute__((__noreturn__))
10 
11 static inline void report(const char *prefix, const char *err, va_list params)
12 {
13 	char msg[1024];
14 	vsnprintf(msg, sizeof(msg), err, params);
15 	fprintf(stderr, " %s%s\n", prefix, msg);
16 }
17 
18 static NORETURN inline void die(const char *err, ...)
19 {
20 	va_list params;
21 
22 	va_start(params, err);
23 	report(" Fatal: ", err, params);
24 	exit(128);
25 	va_end(params);
26 }
27 
28 #define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
29 
30 #define alloc_nr(x) (((x)+16)*3/2)
31 
32 /*
33  * Realloc the buffer pointed at by variable 'x' so that it can hold
34  * at least 'nr' entries; the number of entries currently allocated
35  * is 'alloc', using the standard growing factor alloc_nr() macro.
36  *
37  * DO NOT USE any expression with side-effect for 'x' or 'alloc'.
38  */
39 #define ALLOC_GROW(x, nr, alloc) \
40 	do { \
41 		if ((nr) > alloc) { \
42 			if (alloc_nr(alloc) < (nr)) \
43 				alloc = (nr); \
44 			else \
45 				alloc = alloc_nr(alloc); \
46 			x = xrealloc((x), alloc * sizeof(*(x))); \
47 		} \
48 	} while(0)
49 
50 static inline void *xrealloc(void *ptr, size_t size)
51 {
52 	void *ret = realloc(ptr, size);
53 	if (!ret && !size)
54 		ret = realloc(ptr, 1);
55 	if (!ret) {
56 		ret = realloc(ptr, size);
57 		if (!ret && !size)
58 			ret = realloc(ptr, 1);
59 		if (!ret)
60 			die("Out of memory, realloc failed");
61 	}
62 	return ret;
63 }
64 
65 #define astrcatf(out, fmt, ...)						\
66 ({									\
67 	char *tmp = *(out);						\
68 	if (asprintf((out), "%s" fmt, tmp ?: "", ## __VA_ARGS__) == -1)	\
69 		die("asprintf failed");					\
70 	free(tmp);							\
71 })
72 
73 static inline void astrcat(char **out, const char *add)
74 {
75 	char *tmp = *out;
76 
77 	if (asprintf(out, "%s%s", tmp ?: "", add) == -1)
78 		die("asprintf failed");
79 
80 	free(tmp);
81 }
82 
83 #endif /* __SUBCMD_UTIL_H */
84