strict aliasing violations.
One somewhat major source of strict-aliasing violations and
related warnings is the SQL_LIST structure. For example,
consider its member function `link_in_list` which takes
a pointer to pointer of type T (any type) as a pointer to
pointer to unsigned char. Dereferencing this pointer, which
is done to reset the next field, violates strict-aliasing
rules and might cause problems for surrounding code that
uses the next field of the object being added to the list.
The solution is to use templates to parametrize the SQL_LIST
structure in order to deference the pointers with compatible
types. As a side bonus, it becomes possible to remove quite
a few casts related to acessing data members of SQL_LIST.
sql/handler.h:
Use the appropriate template type argument.
sql/item.cc:
Remove now-unnecessary cast.
sql/item_subselect.cc:
Remove now-unnecessary casts.
sql/item_sum.cc:
Use the appropriate template type argument.
Remove now-unnecessary cast.
sql/mysql_priv.h:
Move SQL_LIST structure to sql_list.h
Use the appropriate template type argument.
sql/sp.cc:
Remove now-unnecessary casts.
sql/sql_delete.cc:
Use the appropriate template type argument.
Remove now-unnecessary casts.
sql/sql_derived.cc:
Remove now-unnecessary casts.
sql/sql_lex.cc:
Remove now-unnecessary casts.
sql/sql_lex.h:
SQL_LIST now takes a template type argument which must
match the type of the elements of the list. Use forward
declaration when the type is not available, it is used
in pointers anyway.
sql/sql_list.h:
Rename SQL_LIST to SQL_I_List. The template parameter is
the type of object that is stored in the list.
sql/sql_olap.cc:
Remove now-unnecessary casts.
sql/sql_parse.cc:
Remove now-unnecessary casts.
sql/sql_prepare.cc:
Remove now-unnecessary casts.
sql/sql_select.cc:
Remove now-unnecessary casts.
sql/sql_show.cc:
Remove now-unnecessary casts.
sql/sql_table.cc:
Remove now-unnecessary casts.
sql/sql_trigger.cc:
Remove now-unnecessary casts.
sql/sql_union.cc:
Remove now-unnecessary casts.
sql/sql_update.cc:
Remove now-unnecessary casts.
sql/sql_view.cc:
Remove now-unnecessary casts.
sql/sql_yacc.yy:
Remove now-unnecessary casts.
storage/myisammrg/ha_myisammrg.cc:
Remove now-unnecessary casts.
strict aliasing violations.
One somewhat major source of strict-aliasing violations and
related warnings is the SQL_LIST structure. For example,
consider its member function `link_in_list` which takes
a pointer to pointer of type T (any type) as a pointer to
pointer to unsigned char. Dereferencing this pointer, which
is done to reset the next field, violates strict-aliasing
rules and might cause problems for surrounding code that
uses the next field of the object being added to the list.
The solution is to use templates to parametrize the SQL_LIST
structure in order to deference the pointers with compatible
types. As a side bonus, it becomes possible to remove quite
a few casts related to acessing data members of SQL_LIST.
- Unify EXPLAIN printout for <subqueryN> tables with regular tables
- Update test results for <subqueryN> tables:
s/unique_key/distinct_key/g
s/1.0/100.0/ for "filtered" column
- Make join buffering take into account that join_tabs are not a
single linear array anymore
- Remove outer join + SJ-Materialization crash (OJ+SJ the processing
is most likely still incorrect)
* remove handler::index_read_last()
* create handler::keyread_read_time() (was get_index_only_read_time() in opt_range.cc)
* ha_show_status() allows engine's show_status() to fail
* remove HTON_FLUSH_AFTER_RENAME
* fix key_cmp_if_same() to work for floats and doubles
* set table->status in the server, don't force engines to do it
* increment status vars in the server, don't force engines to do it
mysql-test/r/status_user.result:
correct test results - innodb was wrongly counting internal
index searches as handler_read_* calls.
sql/ha_partition.cc:
compensate for handler incrementing status counters -
we want to count only calls to underlying engines
sql/handler.h:
inline methods moved to sql_class.h
sql/key.cc:
simplify the check
sql/opt_range.cc:
move get_index_only_read_time to the handler class
sql/sp.cc:
don't use a key that's stored in the record buffer -
the engine can overwrite the buffer with anything, destroying the key
sql/sql_class.h:
inline handler methods that need to see THD and TABLE definitions
sql/sql_select.cc:
no ha_index_read_last_map anymore
sql/sql_table.cc:
remove HTON_FLUSH_AFTER_RENAME
sql/table.cc:
set HA_CAN_MEMCMP as appropriate
sql/tztime.cc:
don't use a key that's stored in the record buffer -
the engine can overwrite the buffer with anything, destroying the key
storage/myisam/ha_myisam.cc:
engines don't need to update table->status or use ha_statistic_increment anymore
storage/myisam/ha_myisam.h:
index_read_last_map is no more
Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).
client/mysql.cc:
Mismatch between prototype and declaration.
client/mysqltest.cc:
mysqltest used to be C code. Use C linkage where appropriate.
cmd-line-utils/readline/input.c:
Isolate unreachable code.
include/my_alloc.h:
Function type must have C linkage.
include/my_base.h:
Function type must have C linkage.
include/my_global.h:
Add helper macros to avoid spurious namespace indentation.
include/mysql.h.pp:
Update ABI file.
mysys/my_gethwaddr.c:
Remove stray carriage return and fix coding style.
plugin/semisync/semisync_master_plugin.cc:
Callback function types have C linkage.
plugin/semisync/semisync_slave_plugin.cc:
Callback function types have C linkage.
sql/derror.cc:
Expected function type has C linkage.
sql/field.cc:
Use helper macro and fix indentation.
sql/handler.cc:
Expected function type has C linkage.
sql/item_sum.cc:
Correct function linkages. Remove now unnecessary cast.
sql/item_sum.h:
Add prototypes with the appropriate linkage as otherwise they
are distinct.
sql/mysqld.cc:
Wrap functions in C linkage mode.
sql/opt_range.cc:
C language linkage is ignored for class member functions.
sql/partition_info.cc:
Add wrapper functions with C linkage for class member functions.
sql/rpl_utility.h:
Use helper macro and fix indentation.
sql/sql_class.cc:
Change type of thd argument -- THD is a class.
Use helper macro and fix indentation.
sql/sql_class.h:
Change type of thd argument -- THD is a class.
sql/sql_select.cc:
Expected function type has C linkage.
sql/sql_select.h:
Move prototype to sql_test.h
sql/sql_show.cc:
Expected function type has C linkage.
sql/sql_test.cc:
Fix required function prototype and fix coding style.
sql/sql_test.h:
Removed unnecessary export and add another.
storage/myisammrg/ha_myisammrg.cc:
Expected function type has C linkage.
storage/perfschema/pfs.cc:
PSI headers are declared with C language linkage, which also
applies to function types.
Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).
There are two problems:
1. In simplify_joins function we calculate table dependencies. If STRAIGHT_JOIN hint
is used for whole SELECT we do not count it and as result some dependendecies
might be lost. It leads to incorrect table order which is returned by
join_tab_cmp_straight() function.
2. make_join_statistics() calculate the transitive closure for relations a particular
JOIN_TAB is 'dependent on'.
We aggregate the dependent table_map of a JOIN_TAB by adding dependencies from other
tables which we depend on. However, this may also cause new dependencies to be
available after we have completed processing a certain JOIN_TAB.
Both these problems affect condition pushdown and as result condition might be pushed
into wrong table which leads to crash or even omitted which leads to wrong result.
The fix:
1. Use modified 'transitive closure' algorithm provided by Ole John Aske
2. Update table dependences in simplify_joins according to
global STRAIGHT_JOIN hint.
Note: the patch also fixes bugs 46091 & 51492
mysql-test/r/join_outer.result:
test case
mysql-test/t/join_outer.test:
test case
sql/sql_select.cc:
1. Use modified 'transitive closure' algorithm provided by Ole John Aske
2. Update table dependences in simplify_joins according to
global STRAIGHT_JOIN hint.
There are two problems:
1. In simplify_joins function we calculate table dependencies. If STRAIGHT_JOIN hint
is used for whole SELECT we do not count it and as result some dependendecies
might be lost. It leads to incorrect table order which is returned by
join_tab_cmp_straight() function.
2. make_join_statistics() calculate the transitive closure for relations a particular
JOIN_TAB is 'dependent on'.
We aggregate the dependent table_map of a JOIN_TAB by adding dependencies from other
tables which we depend on. However, this may also cause new dependencies to be
available after we have completed processing a certain JOIN_TAB.
Both these problems affect condition pushdown and as result condition might be pushed
into wrong table which leads to crash or even omitted which leads to wrong result.
The fix:
1. Use modified 'transitive closure' algorithm provided by Ole John Aske
2. Update table dependences in simplify_joins according to
global STRAIGHT_JOIN hint.
Note: the patch also fixes bugs 46091 & 51492
- Change "SUBQUERY#n" to "<subquery{n}>" in EXPLAIN output. We need to it to be
lowercase so that EXPLAIN results do not differ in case between systems with
case-sensitive and case-insensitive filesystems.
- Remove garbage comments, add better comments.
Fixed some bugs introduced in 5.1.47
Disabled some tests until we have merged with latest Xtradb
configure.in:
Added testing if valgrind/memcheck.h exists
storage/pbxt/src/ha_pbxt.cc:
LOCK_plugin is not anymore locked in init
- Code cleanu.
- Make MWL#90 code require @@optimizer_switch='semijoin=on'
- Update test results with the above
- Fork subselect_mat.test - we want to check both semi-join materialization,
which now has broader scope and non-semijoin materialization.
- INSERT with RAND() doesn't require row based logging again
- Some bugs fixed in opt_range() where we table->key_read was wrongly used
.bzrignore:
Ignore new xtstat binary
mysql-test/r/index_merge_myisam.result:
Update results (old result was wrong)
mysql-test/suite/binlog/r/binlog_stm_binlog.result:
Added drop table first
mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
Added test for when RAND() requires row based logging
mysql-test/suite/binlog/t/binlog_stm_binlog.test:
Added drop table first
mysql-test/suite/binlog/t/binlog_stm_unsafe_warning.test:
Added test for when RAND() requires row based logging
scripts/make_binary_distribution.sh:
Removed type from last commit
sql/item_create.cc:
Don't require row based logging when using RAND() with INSERT
sql/opt_range.cc:
Revert wrong patch from Oracle:
- As QUICK_RANGE_SELECT uses it's own 'file' handler to the tables, one can't use 'table->key_read' as a flag to detect if index only read (keyread) is used or not
- Don't set keyread if keyread is already enabled
- Don't disable key read, if we didn't enable it ourselves
- Simplify code (and ensure that we do proper cleanup of index only read)
sql/opt_range.h:
Added flags to detect if the range optimizer enabled index only read (key read) or not
sql/opt_sum.cc:
Use our more optimized macros
sql/sql_lex.h:
Added 'readable' function to check if we are in a sub query function or not (not normal query or sub query in FROM clause)
sql/sql_select.cc:
Use our more optimized keyread macros
Added ASSERTS early
Simplify code on eliminate_item_equal()
Fixed that substitute_for_best_equal_field() doesn't core dump in case of out of memory conditions.
Removed not needed test for 'field->maybe_null()'
Replaced master_unit()->item with is_subquery_function() (More readable)
sql/sql_update.cc:
Use our more optimized keyread macros
sql/table.cc:
Use our more optimized keyread macros
sql/table.h:
Use separate functions to enable/disable Index only reads
- Safer, more readable, better logging and faster.
Conflicts:
Text conflict in mysql-test/r/grant.result
Text conflict in mysql-test/t/grant.test
Text conflict in mysys/mf_loadpath.c
Text conflict in sql/slave.cc
Text conflict in sql/sql_priv.h
Conflicts:
Text conflict in mysql-test/r/grant.result
Text conflict in mysql-test/t/grant.test
Text conflict in mysys/mf_loadpath.c
Text conflict in sql/slave.cc
Text conflict in sql/sql_priv.h
Conflicts:
Text conflict in mysql-test/r/explain.result
Text conflict in mysql-test/t/explain.test
Text conflict in sql/net_serv.cc
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_priv.h
Conflicts:
Text conflict in mysql-test/r/explain.result
Text conflict in mysql-test/t/explain.test
Text conflict in sql/net_serv.cc
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_priv.h
The fix actually reverts the change introduced
by the patch for bug 51494.
The fact is that patches for bugs 52177&48419
fix bugs 51194&50575 as well.
mysql-test/r/innodb_mysql.result:
test case
mysql-test/t/innodb_mysql.test:
test case
sql/sql_select.cc:
reverted wrong fix for bug 51494
greedy_search optimizer_search_depth=0
The algorithm inside restore_prev_nj_state failed to
properly update the counters within the NESTED_JOIN
tree. The counter was decremented each time a table in the
node was removed from the QEP, the correct thing to do being
only to decrement it when the last table in the child node
was removed from the plan. This lead to node counters
getting negative values and the plan thus appeared
impossible. An assertion caught this.
Fixed by not recursing up the tree unless the last table in
the join nest node is removed from the plan
greedy_search optimizer_search_depth=0
The algorithm inside restore_prev_nj_state failed to
properly update the counters within the NESTED_JOIN
tree. The counter was decremented each time a table in the
node was removed from the QEP, the correct thing to do being
only to decrement it when the last table in the child node
was removed from the plan. This lead to node counters
getting negative values and the plan thus appeared
impossible. An assertion caught this.
Fixed by not recursing up the tree unless the last table in
the join nest node is removed from the plan
