MDEV-6137 better help for SET/ENUM sysvars

Auto-generate the allowed list of values for enum/set/flagset options
in --help output. But don't do that when the help text already has them.

Also, remove lists of values from help strings of various options, where
they were simply listed without any additional information.

1 files changed, 19 insertions, 71 deletions

diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index cf92a5e6197..913ae9d4d4f 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -483,9 +483,7 @@ static Sys_var_enum Sys_binlog_format(
        "based binary logging except for those statements where only row-"
        "based is correct: those which involve user-defined functions (i.e. "
        "UDFs) or the UUID() function; for those, row-based binary logging is "
-       "automatically used. If NDBCLUSTER is enabled and binlog-format is "
-       "MIXED, the format switches to row-based and back implicitly per each "
-       "query accessing an NDBCLUSTER table",
+       "automatically used.",
        SESSION_VAR(binlog_format), CMD_LINE(REQUIRED_ARG, OPT_BINLOG_FORMAT),
        binlog_format_names, DEFAULT(BINLOG_FORMAT_STMT),
        NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(binlog_format_check),
@@ -649,8 +647,7 @@ static Sys_var_struct Sys_character_set_filesystem(
 
 static const char *completion_type_names[]= {"NO_CHAIN", "CHAIN", "RELEASE", 0};
 static Sys_var_enum Sys_completion_type(
-       "completion_type", "The transaction completion type, one of "
-       "NO_CHAIN, CHAIN, RELEASE",
+       "completion_type", "The transaction completion type",
        SESSION_VAR(completion_type), CMD_LINE(REQUIRED_ARG),
        completion_type_names, DEFAULT(0));
 
@@ -717,8 +714,7 @@ static Sys_var_struct Sys_collation_server(
 
 static const char *concurrent_insert_names[]= {"NEVER", "AUTO", "ALWAYS", 0};
 static Sys_var_enum Sys_concurrent_insert(
-       "concurrent_insert", "Use concurrent insert with MyISAM. Possible "
-       "values are NEVER, AUTO, ALWAYS",
+       "concurrent_insert", "Use concurrent insert with MyISAM",
        GLOBAL_VAR(myisam_concurrent_insert), CMD_LINE(OPT_ARG),
        concurrent_insert_names, DEFAULT(1));
 
@@ -2196,37 +2192,7 @@ static bool fix_optimizer_switch(sys_var *self, THD *thd,
 }
 static Sys_var_flagset Sys_optimizer_switch(
        "optimizer_switch",
-       "optimizer_switch=option=val[,option=val...], where option is one of {"
-        "derived_merge, "
-        "derived_with_keys, "
-        "firstmatch, "
-        "in_to_exists, "
-        "engine_condition_pushdown, "
-        "index_condition_pushdown, "
-        "index_merge, "
-        "index_merge_intersection, "
-        "index_merge_sort_intersection, "
-        "index_merge_sort_union, "
-        "index_merge_union, "
-        "join_cache_bka, "
-        "join_cache_hashed, "
-        "join_cache_incremental, "
-        "loosescan, "
-        "materialization, "
-        "mrr, "
-        "mrr_cost_based, "
-        "mrr_sort_keys, "
-        "optimize_join_buffer_size, "
-        "outer_join_with_cache, "
-        "partial_match_rowid_merge, "
-        "partial_match_table_scan, "
-        "semijoin, "
-        "semijoin_with_cache, "
-        "subquery_cache, "
-        "table_elimination, "
-        "extended_keys, "
-        "exists_to_in "
-       "} and val is one of {on, off, default}",
+       "Fine-tune the optimizer behavior",
        SESSION_VAR(optimizer_switch), CMD_LINE(REQUIRED_ARG),
        optimizer_switch_names, DEFAULT(OPTIMIZER_SWITCH_DEFAULT),
        NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL),
@@ -2546,12 +2512,8 @@ static const char *thread_handling_names[]=
 
 static Sys_var_enum Sys_thread_handling(
        "thread_handling",
-       "Define threads usage for handling queries, one of "
-       "one-thread-per-connection, no-threads"
-#ifdef HAVE_POOL_OF_THREADS
-       ", pool-of-threads"
-#endif
-       , READ_ONLY GLOBAL_VAR(thread_handling), CMD_LINE(REQUIRED_ARG),
+       "Define threads usage for handling queries",
+       READ_ONLY GLOBAL_VAR(thread_handling), CMD_LINE(REQUIRED_ARG),
        thread_handling_names, 
        DEFAULT(DEFAULT_THREAD_HANDLING)
  );
@@ -2758,11 +2720,9 @@ static Sys_var_enum Slave_run_triggers_for_rbr(
 static const char *slave_type_conversions_name[]= {"ALL_LOSSY", "ALL_NON_LOSSY", 0};
 static Sys_var_set Slave_type_conversions(
        "slave_type_conversions",
-       "Set of slave type conversions that are enabled. Legal values are:"
-       " ALL_LOSSY to enable lossy conversions and"
-       " ALL_NON_LOSSY to enable non-lossy conversions."
-       " If the variable is assigned the empty set, no conversions are"
-       " allowed and it is expected that the types match exactly.",
+       "Set of slave type conversions that are enabled."
+       " If the variable is empty, no conversions are"
+       " allowed and it is expected that the types match exactly",
        GLOBAL_VAR(slave_type_conversions_options), CMD_LINE(REQUIRED_ARG),
        slave_type_conversions_name,
        DEFAULT(0));
@@ -2785,7 +2745,7 @@ static Sys_var_mybool Sys_master_verify_checksum(
 
 /* These names must match RPL_SKIP_XXX #defines in slave.h. */
 static const char *replicate_events_marked_for_skip_names[]= {
-  "replicate", "filter_on_slave", "filter_on_master", 0
+  "REPLICATE", "FILTER_ON_SLAVE", "FILTER_ON_MASTER", 0
 };
 
 bool
@@ -2931,8 +2891,7 @@ export bool sql_mode_string_representation(THD *thd, ulonglong sql_mode,
 */
 static Sys_var_set Sys_sql_mode(
        "sql_mode",
-       "Syntax: sql-mode=mode[,mode[,mode...]]. See the manual for the "
-       "complete list of valid sql modes",
+       "Sets the sql mode",
        SESSION_VAR(sql_mode), CMD_LINE(REQUIRED_ARG),
        sql_mode_names, DEFAULT(0), NO_MUTEX_GUARD, NOT_IN_BINLOG,
        ON_CHECK(check_sql_mode), ON_UPDATE(fix_sql_mode));
@@ -2957,9 +2916,7 @@ export bool old_mode_string_representation(THD *thd, ulonglong sql_mode,
 */
 static Sys_var_set Sys_old_behavior(
        "old_mode",
-       "Used to emulate old behavior from earlier MariaDB or MySQL versions. "
-       "Syntax: old_mode=mode[,mode[,mode...]]. "
-       "See the manual for the complete list of valid old modes",
+       "Used to emulate old behavior from earlier MariaDB or MySQL versions",
        SESSION_VAR(old_behavior), CMD_LINE(REQUIRED_ARG),
        old_mode_names, DEFAULT(0), NO_MUTEX_GUARD, NOT_IN_BINLOG);
 
@@ -4009,8 +3966,7 @@ static bool fix_log_output(sys_var *self, THD *thd, enum_var_type type)
 static const char *log_output_names[] = { "NONE", "FILE", "TABLE", NULL};
 
 static Sys_var_set Sys_log_output(
-       "log_output", "Syntax: log-output=value[,value...], "
-       "where \"value\" could be TABLE, FILE or NONE",
+       "log_output", "How logs should be written",
        GLOBAL_VAR(log_output_options), CMD_LINE(REQUIRED_ARG),
        log_output_names, DEFAULT(LOG_FILE), NO_MUTEX_GUARD, NOT_IN_BINLOG,
        ON_CHECK(check_not_empty_set), ON_UPDATE(fix_log_output));
@@ -4494,9 +4450,8 @@ export const char *plugin_maturity_names[]=
 { "unknown", "experimental", "alpha", "beta", "gamma", "stable", 0 };
 static Sys_var_enum Sys_plugin_maturity(
        "plugin_maturity",
-       "The lowest desirable plugin maturity "
-       "(unknown, experimental, alpha, beta, gamma, or stable). "
-       "Plugins less mature than that will not be installed or loaded.",
+       "The lowest desirable plugin maturity. "
+       "Plugins less mature than that will not be installed or loaded",
        READ_ONLY GLOBAL_VAR(plugin_maturity), CMD_LINE(REQUIRED_ARG),
        plugin_maturity_names, DEFAULT(MariaDB_PLUGIN_MATURITY_UNKNOWN));
 
@@ -4567,10 +4522,7 @@ static const char *log_slow_filter_names[]=
 };
 static Sys_var_set Sys_log_slow_filter(
        "log_slow_filter",
-       "Log only certain types of queries. Multiple "
-       "flags can be specified, separated by commas. Valid values are admin, "
-       "slave, filesort, filesort_on_disk, full_join, full_scan, query_cache, "
-       "query_cache_miss, tmp_table, tmp_table_on_disk",
+       "Log only certain types of queries",
        SESSION_VAR(log_slow_filter), CMD_LINE(REQUIRED_ARG),
        log_slow_filter_names,
        DEFAULT(MAX_SET(array_elements(log_slow_filter_names)-1)));
@@ -4608,9 +4560,7 @@ int default_regex_flags_pcre(const THD *thd)
 }
 static Sys_var_set Sys_default_regex_flags(
        "default_regex_flags",
-       "Default flags for the regex library. "
-       "Syntax: default-regex-flags='[flag[,flag[,flag...]]]'. "
-       "See the manual for the complete list of valid flags",
+       "Default flags for the regex library",
        SESSION_VAR(default_regex_flags), CMD_LINE(REQUIRED_ARG),
        default_regex_flags_names,
        DEFAULT(0));
@@ -4627,8 +4577,7 @@ static const char *log_slow_verbosity_names[]= { "innodb", "query_plan",
                                                  "explain", 0 };
 static Sys_var_set Sys_log_slow_verbosity(
        "log_slow_verbosity",
-       "log-slow-verbosity=[value[,value ...]] where value is one of "
-       "'innodb', 'query_plan', 'explain' ",
+       "Verbosity level for the slow log",
        SESSION_VAR(log_slow_verbosity), CMD_LINE(REQUIRED_ARG),
        log_slow_verbosity_names, DEFAULT(LOG_SLOW_VERBOSITY_INIT));
 
@@ -4694,8 +4643,7 @@ const char *use_stat_tables_modes[] =
            {"NEVER", "COMPLEMENTARY", "PREFERABLY", 0};
 static Sys_var_enum Sys_optimizer_use_stat_tables(
        "use_stat_tables",
-       "Specifies how to use system statistics tables. Possible values are "
-       "NEVER, COMPLEMENTARY, PREFERABLY",
+       "Specifies how to use system statistics tables",
        SESSION_VAR(use_stat_tables), CMD_LINE(REQUIRED_ARG),
        use_stat_tables_modes, DEFAULT(0));