commit 8d685aee7c89bc0118a4550c1bb5a3c82dfb4c4c Author: Nick Mathewson nickm@torproject.org Date: Thu Sep 5 11:48:32 2019 -0400

config: rename "contained" to "derived", and explain it better.

Don't use "derived" directly, but check its implications for listing and copying. --- src/app/config/confparse.c | 54 +++++++++++++++++++++++++++++++++++++++------- src/app/config/confparse.h | 1 - 2 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/src/app/config/confparse.c b/src/app/config/confparse.c index 1923a0c1e..361500466 100644 --- a/src/app/config/confparse.c +++ b/src/app/config/confparse.c @@ -551,13 +551,52 @@ config_var_is_gettable(const config_var_t *var) return true; }

-bool -config_var_is_contained(const config_var_t *var) +/** + * Return true iff this is variable is "derived" from another -- that is, + * inspecting this variable inspects part of another, and changing this + * variable changes part of another. + * + * Derived variables require special handling in several ways: they do not + * need to be copied independently when we are copying a config object, since + * copying the variable they are derived from copies them too. Similarly, + * they do not need to be compared independently when listing changes, since + * comparing the variable that they are derived from compares them too. + **/ +static bool +config_var_is_derived(const config_var_t *var) { return struct_var_is_contained(&var->member); }

/** + * Return true iff we need to check <b>var</b> for changes when we are + * comparing config options for changes. + * + * A false result might mean that the variable is a derived variable, and that + * comparing the variable it derives from compares this one too-- or it might + * mean that there is no data to compare. + **/ +static bool +config_var_should_list_changes(const config_var_t *var) +{ + return ! config_var_is_derived(var); +} + +/** + * Return true iff we need to copy the data for <b>var</b> when we are + * copying a config option. + * + * A false option might mean that the variable is a derived variable, and that + * copying the variable it derives from copies it-- or it might mean that + * there is no data to copy. + **/ +static bool +config_var_needs_copy(const config_var_t *var) +{ + return ! config_var_is_derived(var); +} + +/**h * Return true iff variable <b>var</b> should appear on list of variables * given to the controller or the CLI. **/ @@ -578,6 +617,9 @@ config_var_is_listable(const config_var_t *var) bool config_var_is_dumpable(const config_var_t *var) { + if (config_var_is_derived(var)) { + return false; + } return (var->flags & CVFLAG_NODUMP) == 0; }

@@ -1037,7 +1079,7 @@ config_get_changes(const config_mgr_t *mgr, config_line_t *result = NULL; config_line_t **next = &result; SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { - if (config_var_is_contained(mv->cvar)) { + if (! config_var_should_list_changes(mv->cvar)) { /* something else will check this var, or it doesn't need checking */ continue; } @@ -1073,7 +1115,7 @@ config_dup(const config_mgr_t *mgr, const void *old)

newopts = config_new(mgr); SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { - if (config_var_is_contained(mv->cvar)) { + if (! config_var_needs_copy(mv->cvar)) { // Something else will copy this option, or it doesn't need copying. continue; } @@ -1140,10 +1182,6 @@ config_dump(const config_mgr_t *mgr, const void *default_options, elements = smartlist_new(); SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { int comment_option = 0; - if (config_var_is_contained(mv->cvar)) { - // Something else will dump this option, or it doesn't need dumping. - continue; - } /* Don't save 'hidden' control variables. */ if (! config_var_is_dumpable(mv->cvar)) continue; diff --git a/src/app/config/confparse.h b/src/app/config/confparse.h index b4c32bf1b..b5d0eb3ba 100644 --- a/src/app/config/confparse.h +++ b/src/app/config/confparse.h @@ -190,7 +190,6 @@ const char *config_expand_abbrev(const config_mgr_t *mgr, void warn_deprecated_option(const char *what, const char *why);

bool config_var_is_settable(const config_var_t *var); -bool config_var_is_contained(const config_var_t *var); bool config_var_is_listable(const config_var_t *var); bool config_var_is_dumpable(const config_var_t *var);