1 #include "cache.h"
2 #include "exec_cmd.h"
3 #include "quote.h"
4 
5 #include <string.h>
6 
7 #define MAX_ARGS	32
8 
9 static const char *argv_exec_path;
10 static const char *argv0_path;
11 
system_path(const char * path)12 const char *system_path(const char *path)
13 {
14 	static const char *prefix = PREFIX;
15 	struct strbuf d = STRBUF_INIT;
16 
17 	if (is_absolute_path(path))
18 		return path;
19 
20 	strbuf_addf(&d, "%s/%s", prefix, path);
21 	path = strbuf_detach(&d, NULL);
22 	return path;
23 }
24 
perf_extract_argv0_path(const char * argv0)25 const char *perf_extract_argv0_path(const char *argv0)
26 {
27 	const char *slash;
28 
29 	if (!argv0 || !*argv0)
30 		return NULL;
31 	slash = argv0 + strlen(argv0);
32 
33 	while (argv0 <= slash && !is_dir_sep(*slash))
34 		slash--;
35 
36 	if (slash >= argv0) {
37 		argv0_path = strndup(argv0, slash - argv0);
38 		return argv0_path ? slash + 1 : NULL;
39 	}
40 
41 	return argv0;
42 }
43 
perf_set_argv_exec_path(const char * exec_path)44 void perf_set_argv_exec_path(const char *exec_path)
45 {
46 	argv_exec_path = exec_path;
47 	/*
48 	 * Propagate this setting to external programs.
49 	 */
50 	setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
51 }
52 
53 
54 /* Returns the highest-priority, location to look for perf programs. */
perf_exec_path(void)55 const char *perf_exec_path(void)
56 {
57 	const char *env;
58 
59 	if (argv_exec_path)
60 		return argv_exec_path;
61 
62 	env = getenv(EXEC_PATH_ENVIRONMENT);
63 	if (env && *env) {
64 		return env;
65 	}
66 
67 	return system_path(PERF_EXEC_PATH);
68 }
69 
add_path(struct strbuf * out,const char * path)70 static void add_path(struct strbuf *out, const char *path)
71 {
72 	if (path && *path) {
73 		if (is_absolute_path(path))
74 			strbuf_addstr(out, path);
75 		else
76 			strbuf_addstr(out, make_nonrelative_path(path));
77 
78 		strbuf_addch(out, PATH_SEP);
79 	}
80 }
81 
setup_path(void)82 void setup_path(void)
83 {
84 	const char *old_path = getenv("PATH");
85 	struct strbuf new_path = STRBUF_INIT;
86 
87 	add_path(&new_path, perf_exec_path());
88 	add_path(&new_path, argv0_path);
89 
90 	if (old_path)
91 		strbuf_addstr(&new_path, old_path);
92 	else
93 		strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
94 
95 	setenv("PATH", new_path.buf, 1);
96 
97 	strbuf_release(&new_path);
98 }
99 
prepare_perf_cmd(const char ** argv)100 static const char **prepare_perf_cmd(const char **argv)
101 {
102 	int argc;
103 	const char **nargv;
104 
105 	for (argc = 0; argv[argc]; argc++)
106 		; /* just counting */
107 	nargv = malloc(sizeof(*nargv) * (argc + 2));
108 
109 	nargv[0] = "perf";
110 	for (argc = 0; argv[argc]; argc++)
111 		nargv[argc + 1] = argv[argc];
112 	nargv[argc + 1] = NULL;
113 	return nargv;
114 }
115 
execv_perf_cmd(const char ** argv)116 int execv_perf_cmd(const char **argv) {
117 	const char **nargv = prepare_perf_cmd(argv);
118 
119 	/* execvp() can only ever return if it fails */
120 	execvp("perf", (char **)nargv);
121 
122 	free(nargv);
123 	return -1;
124 }
125 
126 
execl_perf_cmd(const char * cmd,...)127 int execl_perf_cmd(const char *cmd,...)
128 {
129 	int argc;
130 	const char *argv[MAX_ARGS + 1];
131 	const char *arg;
132 	va_list param;
133 
134 	va_start(param, cmd);
135 	argv[0] = cmd;
136 	argc = 1;
137 	while (argc < MAX_ARGS) {
138 		arg = argv[argc++] = va_arg(param, char *);
139 		if (!arg)
140 			break;
141 	}
142 	va_end(param);
143 	if (MAX_ARGS <= argc)
144 		return error("too many args to run %s", cmd);
145 
146 	argv[argc] = NULL;
147 	return execv_perf_cmd(argv);
148 }
149