strict aliasing violations.
Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.
As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.
The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.
This patch:
- Moves all definitions from the mysql_priv.h file into
header files for the component where the variable is
defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
Several functions (mostly in mysqld.cc) directly call
exit() function in case of errors, which is not a desired
behaviour expecially in the embedded-server library.
Fixed by making these functions return error sign instead
of exiting.
per-file comments:
include/my_getopt.h
Bug#39289 libmysqld.a calls exit() upon error
added 'error' retvalue for my_getopt_register_get_addr
libmysqld/lib_sql.cc
Bug#39289 libmysqld.a calls exit() upon error
unireg_clear() function implemented
mysys/default.c
Bug#39289 libmysqld.a calls exit() upon error
error returned instead of exit() call
mysys/mf_tempdir.c
Bug#39289 libmysqld.a calls exit() upon error
free_tmpdir() - fixed so it's not produce crash on uninitialized
tmpdir structure
mysys/my_getopt.c
Bug#39289 libmysqld.a calls exit() upon error
error returned instead of exit() call
sql/mysql_priv.h
Bug#39289 libmysqld.a calls exit() upon error
unireg_abort definition fixed for the embedded server
sql/mysqld.cc
Bug#39289 libmysqld.a calls exit() upon error
various functions fixed
error returned instead of exit() call
value" error even though the value was correct): a C function in my_getopt.c
was taking bool* in parameter and was called from C++ sql_plugin.cc,
but on some Mac OS X sizeof(bool) is 1 in C and 4 in C++, giving funny
mismatches. Fixed, all other occurences of bool in C are removed, future
ones are blocked by a "C-bool-catcher" in my_global.h (use my_bool).
Default values of variables were not subject to upper/lower bounds
and step, while setting variables was. Bounds and step are also
applied to defaults now; defaults are corrected quietly, values
given by the user are corrected, and a correction-warning is thrown
as needed. Lastly, very large values could wrap around, starting
from 0 again. They are bounded at the maximum value for the
respective data-type now if no lower maximum is specified in the
variable's definition.
"Disabled plugin is provoking Valgrind error"
If there are any auto-alloced string plug-in options, memory is
allocated during the call for handle_options(). We must free this
memory if we are not installing the plug-in.
--long-query-time is now given in seconds with microseconds as decimals
--min_examined_row_limit added for slow query log
long_query_time user variable is now double with 6 decimals
Added functions to get time in microseconds
Added faster time() functions for system that has gethrtime() (Solaris)
We now do less time() calls.
Added field->in_read_set() and field->in_write_set() for easier field manipulation by handlers
set_var.cc and my_getopt() can now handle DOUBLE variables.
All time() calls changed to my_time()
my_time() now does retry's if time() call fails.
Added debug function for stopping in mysql_admin_table() when tables are locked
Some trivial function and struct variable renames to avoid merge errors.
Fixed compiler warnings
Initialization of some time variables on windows moved to my_init()
The following type conversions was done:
- Changed byte to uchar
- Changed gptr to uchar*
- Change my_string to char *
- Change my_size_t to size_t
- Change size_s to size_t
Removed declaration of byte, gptr, my_string, my_size_t and size_s.
Following function parameter changes was done:
- All string functions in mysys/strings was changed to use size_t
instead of uint for string lengths.
- All read()/write() functions changed to use size_t (including vio).
- All protocoll functions changed to use size_t instead of uint
- Functions that used a pointer to a string length was changed to use size_t*
- Changed malloc(), free() and related functions from using gptr to use void *
as this requires fewer casts in the code and is more in line with how the
standard functions work.
- Added extra length argument to dirname_part() to return the length of the
created string.
- Changed (at least) following functions to take uchar* as argument:
- db_dump()
- my_net_write()
- net_write_command()
- net_store_data()
- DBUG_DUMP()
- decimal2bin() & bin2decimal()
- Changed my_compress() and my_uncompress() to use size_t. Changed one
argument to my_uncompress() from a pointer to a value as we only return
one value (makes function easier to use).
- Changed type of 'pack_data' argument to packfrm() to avoid casts.
- Changed in readfrm() and writefrom(), ha_discover and handler::discover()
the type for argument 'frmdata' to uchar** to avoid casts.
- Changed most Field functions to use uchar* instead of char* (reduced a lot of
casts).
- Changed field->val_xxx(xxx, new_ptr) to take const pointers.
Other changes:
- Removed a lot of not needed casts
- Added a few new cast required by other changes
- Added some cast to my_multi_malloc() arguments for safety (as string lengths
needs to be uint, not size_t).
- Fixed all calls to hash-get-key functions to use size_t*. (Needed to be done
explicitely as this conflict was often hided by casting the function to
hash_get_key).
- Changed some buffers to memory regions to uchar* to avoid casts.
- Changed some string lengths from uint to size_t.
- Changed field->ptr to be uchar* instead of char*. This allowed us to
get rid of a lot of casts.
- Some changes from true -> TRUE, false -> FALSE, unsigned char -> uchar
- Include zlib.h in some files as we needed declaration of crc32()
- Changed MY_FILE_ERROR to be (size_t) -1.
- Changed many variables to hold the result of my_read() / my_write() to be
size_t. This was needed to properly detect errors (which are
returned as (size_t) -1).
- Removed some very old VMS code
- Changed packfrm()/unpackfrm() to not be depending on uint size
(portability fix)
- Removed windows specific code to restore cursor position as this
causes slowdown on windows and we should not mix read() and pread()
calls anyway as this is not thread safe. Updated function comment to
reflect this. Changed function that depended on original behavior of
my_pwrite() to itself restore the cursor position (one such case).
- Added some missing checking of return value of malloc().
- Changed definition of MOD_PAD_CHAR_TO_FULL_LENGTH to avoid 'long' overflow.
- Changed type of table_def::m_size from my_size_t to ulong to reflect that
m_size is the number of elements in the array, not a string/memory
length.
- Moved THD::max_row_length() to table.cc (as it's not depending on THD).
Inlined max_row_length_blob() into this function.
- More function comments
- Fixed some compiler warnings when compiled without partitions.
- Removed setting of LEX_STRING() arguments in declaration (portability fix).
- Some trivial indentation/variable name changes.
- Some trivial code simplifications:
- Replaced some calls to alloc_root + memcpy to use
strmake_root()/strdup_root().
- Changed some calls from memdup() to strmake() (Safety fix)
- Simpler loops in client-simple.c
"Server Variables for Plugins"
Implement support for plugins to declare server variables.
Demonstrate functionality by removing InnoDB specific code from sql/*
New feature for HASH - HASH_UNIQUE flag
New feature for DYNAMIC_ARRAY - initializer accepts preallocated ptr.
Completed support for plugin reference counting.
Corrected spelling in copyright text
Makefile.am:
Don't update the files from BitKeeper
Many files:
Removed "MySQL Finland AB & TCX DataKonsult AB" from copyright header
Adjusted year(s) in copyright header
Many files:
Added GPL copyright text
Removed files:
Docs/Support/colspec-fix.pl
Docs/Support/docbook-fixup.pl
Docs/Support/docbook-prefix.pl
Docs/Support/docbook-split
Docs/Support/make-docbook
Docs/Support/make-makefile
Docs/Support/test-make-manual
Docs/Support/test-make-manual-de
Docs/Support/xwf
used in the handle_options() function (instead of using additional
handle_option() parameter). The default value of the
my_getopt_error_reporter is default_reporter(). One can set it to
other functions if case of need.
my_getopt.c:
Moved the inclusion of my_getopt.h down below the inclusion of my_sys.h so that enum loglevel definition would be available
my_sys.h, my_getopt.h:
moved definition of enum loglevel from my_getopt.h to my_sys.h
mysqld.cc:
Changed LOGLEVEL enum to loglevel
mysql_priv.h, log.cc:
Changed LOGLEVEL to loglevel. Removed startup_ from some of the DBUG_ENTER macros. Removed the print_msg_to_log function as it was unused.
my_getopt.c, my_getopt.h:
Renamed LOGLEVEL to loglevel to match coding standards
mysqld.cc:
Changed option_error_reporter to match new function header that includes LOGLEVEL enum
mysql_priv.h:
Removed the MY_ERROR style bitmask. Changed function headers to use new LOGLEVEL enum
log.cc:
Changed print_buffer_to_log to print_buffer_to_file. Remove the timestamp bool and now all log entries written to stderr are timestamped. Removed some unused commented code. changed to use the new LOGLEVEL enum.
my_getopt.c:
Changed functions to use the new LOGLEVEL enum and changed the included error reporter to be default_reporter. This reporter is used in handle_options if a reporter is not given
my_getopt.h:
changed typedefs to use better naming convention. Moved error bitmask into the LOGLEVEL enum and included it here.
Added declarations for print_msg_to_log and vprint_msg_to_log. sql_print_error are simple functions that wrap calls to print_msg_to_log. Define the different error types with MY_ERROR_TYPE, MY_WARNING_TYPE, and MY_INFORMATION_TYPE
gen_lex_hash.cc:
Added NULL error reporting parameter to handle_options
log.cc:
Add print_msg_to_log, print_buffer_to_log, and vprint_msg_to_log. Print_msg_to_log will write the message to the windows event log if on NT. We now have error, warning, and information versions of sql_print_xxxx. T his is a variation of a similar changeset WAX did.
mysqld.cc:
Added option_error_reporter callback function and pass that into handle_options
mysql.cc:
Added NULL as error reporter arg to the end of handle_options
Many files:
Added NULL error reporter parameter as the last paramter to handle_options
my_getopt.c:
Added second function pointer to server as an error reporting callback. Added local function report_option_error that will either write the error to stderr or to the error reporting callback. changed all calls in handle_options from fprintf(stderr, ... ) to report_option_error
my_getopt.h:
Changed declaration of handle_options to use typedefs for the two function pointers. added second function pointer to server as an error reporting callback
mysqld.dsp:
Added custom build step for compiling message file and added message resource file (output of mc)
- Fixed Bug#2346
- Fixed Bug#2378
- Fixed bug in pager (no Bug#ID (?))
- Added support for new special situations option type, GET_DISABLED.
See handling of --debug in mysql.cc. compiled wihtout debugging, as an
example.
Made a some new buffers thread specific and changeable.
Resize of key_buffer.
AUTO_COMMIT -> AUTOCOMMIT
Fixed mutex bug in DROP DATABASE
Fixed bug when using auto_increment as second part of a key where first part could include NULL.
Split handler->extra() to extra() and extra_opt() to be able to support thread specific buffers.
Don't write message to error log when slave reconnects becasue of timeout.
Fixed possible update problem when using DELETE/UPDATE on small tables
(In some cases we used index even if table scanning would be better)
A lot of minior code cleanups
of an error in option handling. This can sometimes be useful in
scripts.
Changed some exit code names and corresponding numbers.
Fixed a bug in mysqld.cc, in replication related options.
Added a global flag in my_getopt, which can be set by any program
that is using my_getopt, which tells whether the client should
print the error message itself, or whether my_getopt should do it.
The default is that my_getopt will print the error messages.
- Fixed some bugs, wrongly freed pointers, in some clients.
- Removed unneccessary code.
- Fixed some other minor bugs and added some options into
variables category, which had accidently been left out earlier.
Bug fix when using --no-deaults
Sets ref_length to right value (faster rnd_pos() handling in InnoDB).
Fixed problem with multi-table-delete and InnoDB
Fixed problem with truncate table, which required a COMMIT before.
Fixed multi-table-delete bug with InnoDB.
Remove not used index from EXPLAIN
Test of unsigned BIGINT values
Fixes for queries-per-hour
Cleanup of replication code (comments and portability fixes)
Make most of the binary log code 4G clean
Changed syntax for GRANT ... QUERIES PER HOUR
