Merge branch 'jk/harden-protocol-v2-delim-handling'
[git] / trace2 / tr2_sysenv.c
1 #include "cache.h"
2 #include "config.h"
3 #include "dir.h"
4 #include "tr2_sysenv.h"
5
6 /*
7  * Each entry represents a trace2 setting.
8  * See Documentation/technical/api-trace2.txt
9  */
10 struct tr2_sysenv_entry {
11         const char *env_var_name;
12         const char *git_config_name;
13
14         char *value;
15         unsigned int getenv_called : 1;
16 };
17
18 /*
19  * This table must match "enum tr2_sysenv_variable" in tr2_sysenv.h.
20  *
21  * The strings in this table are constant and must match the published
22  * config and environment variable names as described in the documentation.
23  *
24  * We do not define entries for the GIT_TRACE2_PARENT_* environment
25  * variables because they are transient and used to pass information
26  * from parent to child git processes, rather than settings.
27  */
28 /* clang-format off */
29 static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
30         [TR2_SYSENV_CFG_PARAM]     = { "GIT_TRACE2_CONFIG_PARAMS",
31                                        "trace2.configparams" },
32         [TR2_SYSENV_ENV_VARS]      = { "GIT_TRACE2_ENV_VARS",
33                                        "trace2.envvars" },
34
35         [TR2_SYSENV_DST_DEBUG]     = { "GIT_TRACE2_DST_DEBUG",
36                                        "trace2.destinationdebug" },
37
38         [TR2_SYSENV_NORMAL]        = { "GIT_TRACE2",
39                                        "trace2.normaltarget" },
40         [TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TRACE2_BRIEF",
41                                        "trace2.normalbrief" },
42
43         [TR2_SYSENV_EVENT]         = { "GIT_TRACE2_EVENT",
44                                        "trace2.eventtarget" },
45         [TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TRACE2_EVENT_BRIEF",
46                                        "trace2.eventbrief" },
47         [TR2_SYSENV_EVENT_NESTING] = { "GIT_TRACE2_EVENT_NESTING",
48                                        "trace2.eventnesting" },
49
50         [TR2_SYSENV_PERF]          = { "GIT_TRACE2_PERF",
51                                        "trace2.perftarget" },
52         [TR2_SYSENV_PERF_BRIEF]    = { "GIT_TRACE2_PERF_BRIEF",
53                                        "trace2.perfbrief" },
54
55         [TR2_SYSENV_MAX_FILES]     = { "GIT_TRACE2_MAX_FILES",
56                                        "trace2.maxfiles" },
57 };
58 /* clang-format on */
59
60 static int tr2_sysenv_cb(const char *key, const char *value, void *d)
61 {
62         int k;
63
64         if (!starts_with(key, "trace2."))
65                 return 0;
66
67         for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
68                 if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
69                         free(tr2_sysenv_settings[k].value);
70                         tr2_sysenv_settings[k].value = xstrdup(value);
71                         return 0;
72                 }
73         }
74
75         return 0;
76 }
77
78 /*
79  * Load Trace2 settings from the system config (usually "/etc/gitconfig"
80  * unless we were built with a runtime-prefix).  These are intended to
81  * define the default values for Trace2 as requested by the administrator.
82  *
83  * Then override with the Trace2 settings from the global config.
84  */
85 void tr2_sysenv_load(void)
86 {
87         if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
88                 BUG("tr2_sysenv_settings size is wrong");
89
90         read_very_early_config(tr2_sysenv_cb, NULL);
91 }
92
93 /*
94  * Return the value for the requested Trace2 setting from these sources:
95  * the system config, the global config, and the environment.
96  */
97 const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
98 {
99         if (var >= TR2_SYSENV_MUST_BE_LAST)
100                 BUG("tr2_sysenv_get invalid var '%d'", var);
101
102         if (!tr2_sysenv_settings[var].getenv_called) {
103                 const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
104                 if (v && *v) {
105                         free(tr2_sysenv_settings[var].value);
106                         tr2_sysenv_settings[var].value = xstrdup(v);
107                 }
108                 tr2_sysenv_settings[var].getenv_called = 1;
109         }
110
111         return tr2_sysenv_settings[var].value;
112 }
113
114 /*
115  * Return a friendly name for this setting that is suitable for printing
116  * in an error messages.
117  */
118 const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
119 {
120         if (var >= TR2_SYSENV_MUST_BE_LAST)
121                 BUG("tr2_sysenv_get invalid var '%d'", var);
122
123         return tr2_sysenv_settings[var].env_var_name;
124 }
125
126 void tr2_sysenv_release(void)
127 {
128         int k;
129
130         for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
131                 free(tr2_sysenv_settings[k].value);
132 }