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
  33         [TR2_SYSENV_DST_DEBUG]     = { "GIT_TRACE2_DST_DEBUG",
  34                                        "trace2.destinationdebug" },
  35
  36         [TR2_SYSENV_NORMAL]        = { "GIT_TRACE2",
  37                                        "trace2.normaltarget" },
  38         [TR2_SYSENV_NORMAL_BRIEF]  = { "GIT_TRACE2_BRIEF",
  39                                        "trace2.normalbrief" },
  40
  41         [TR2_SYSENV_EVENT]         = { "GIT_TRACE2_EVENT",
  42                                        "trace2.eventtarget" },
  43         [TR2_SYSENV_EVENT_BRIEF]   = { "GIT_TRACE2_EVENT_BRIEF",
  44                                        "trace2.eventbrief" },
  45         [TR2_SYSENV_EVENT_NESTING] = { "GIT_TRACE2_EVENT_NESTING",
  46                                        "trace2.eventnesting" },
  47
  48         [TR2_SYSENV_PERF]          = { "GIT_TRACE2_PERF",
  49                                        "trace2.perftarget" },
  50         [TR2_SYSENV_PERF_BRIEF]    = { "GIT_TRACE2_PERF_BRIEF",
  51                                        "trace2.perfbrief" },
  52 };
  53 /* clang-format on */
  54
  55 static int tr2_sysenv_cb(const char *key, const char *value, void *d)
  56 {
  57         int k;
  58
  59         if (!starts_with(key, "trace2."))
  60                 return 0;
  61
  62         for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
  63                 if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
  64                         free(tr2_sysenv_settings[k].value);
  65                         tr2_sysenv_settings[k].value = xstrdup(value);
  66                         return 0;
  67                 }
  68         }
  69
  70         return 0;
  71 }
  72
  73 /*
  74  * Load Trace2 settings from the system config (usually "/etc/gitconfig"
  75  * unless we were built with a runtime-prefix).  These are intended to
  76  * define the default values for Trace2 as requested by the administrator.
  77  *
  78  * Then override with the Trace2 settings from the global config.
  79  */
  80 void tr2_sysenv_load(void)
  81 {
  82         if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
  83                 BUG("tr2_sysenv_settings size is wrong");
  84
  85         read_very_early_config(tr2_sysenv_cb, NULL);
  86 }
  87
  88 /*
  89  * Return the value for the requested Trace2 setting from these sources:
  90  * the system config, the global config, and the environment.
  91  */
  92 const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
  93 {
  94         if (var >= TR2_SYSENV_MUST_BE_LAST)
  95                 BUG("tr2_sysenv_get invalid var '%d'", var);
  96
  97         if (!tr2_sysenv_settings[var].getenv_called) {
  98                 const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
  99                 if (v && *v) {
 100                         free(tr2_sysenv_settings[var].value);
 101                         tr2_sysenv_settings[var].value = xstrdup(v);
 102                 }
 103                 tr2_sysenv_settings[var].getenv_called = 1;
 104         }
 105
 106         return tr2_sysenv_settings[var].value;
 107 }
 108
 109 /*
 110  * Return a friendly name for this setting that is suitable for printing
 111  * in an error messages.
 112  */
 113 const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
 114 {
 115         if (var >= TR2_SYSENV_MUST_BE_LAST)
 116                 BUG("tr2_sysenv_get invalid var '%d'", var);
 117
 118         return tr2_sysenv_settings[var].env_var_name;
 119 }
 120
 121 void tr2_sysenv_release(void)
 122 {
 123         int k;
 124
 125         for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
 126                 free(tr2_sysenv_settings[k].value);
 127 }