trace2/tr2_sysenv.c

   1 #include "git-compat-util.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,
  61                          const struct config_context *ctx UNUSED, void *d)
  62 {
  63         int k;
  64
  65         if (!starts_with(key, "trace2."))
  66                 return 0;
  67
  68         for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++) {
  69                 if (!strcmp(key, tr2_sysenv_settings[k].git_config_name)) {
  70                         free(tr2_sysenv_settings[k].value);
  71                         tr2_sysenv_settings[k].value = xstrdup(value);
  72                         return 0;
  73                 }
  74         }
  75
  76         return 0;
  77 }
  78
  79 /*
  80  * Load Trace2 settings from the system config (usually "/etc/gitconfig"
  81  * unless we were built with a runtime-prefix).  These are intended to
  82  * define the default values for Trace2 as requested by the administrator.
  83  *
  84  * Then override with the Trace2 settings from the global config.
  85  */
  86 void tr2_sysenv_load(void)
  87 {
  88         if (ARRAY_SIZE(tr2_sysenv_settings) != TR2_SYSENV_MUST_BE_LAST)
  89                 BUG("tr2_sysenv_settings size is wrong");
  90
  91         read_very_early_config(tr2_sysenv_cb, NULL);
  92 }
  93
  94 /*
  95  * Return the value for the requested Trace2 setting from these sources:
  96  * the system config, the global config, and the environment.
  97  */
  98 const char *tr2_sysenv_get(enum tr2_sysenv_variable var)
  99 {
 100         if (var >= TR2_SYSENV_MUST_BE_LAST)
 101                 BUG("tr2_sysenv_get invalid var '%d'", var);
 102
 103         if (!tr2_sysenv_settings[var].getenv_called) {
 104                 const char *v = getenv(tr2_sysenv_settings[var].env_var_name);
 105                 if (v && *v) {
 106                         free(tr2_sysenv_settings[var].value);
 107                         tr2_sysenv_settings[var].value = xstrdup(v);
 108                 }
 109                 tr2_sysenv_settings[var].getenv_called = 1;
 110         }
 111
 112         return tr2_sysenv_settings[var].value;
 113 }
 114
 115 /*
 116  * Return a friendly name for this setting that is suitable for printing
 117  * in an error messages.
 118  */
 119 const char *tr2_sysenv_display_name(enum tr2_sysenv_variable var)
 120 {
 121         if (var >= TR2_SYSENV_MUST_BE_LAST)
 122                 BUG("tr2_sysenv_get invalid var '%d'", var);
 123
 124         return tr2_sysenv_settings[var].env_var_name;
 125 }
 126
 127 void tr2_sysenv_release(void)
 128 {
 129         int k;
 130
 131         for (k = 0; k < ARRAY_SIZE(tr2_sysenv_settings); k++)
 132                 free(tr2_sysenv_settings[k].value);
 133 }