This patch is the result of running
run-clang-tidy -fix -header-filter=.* -checks='-*,modernize-use-equals-default' .
Code style changes have been done on top. The result of this change
leads to the following improvements:
1. Binary size reduction.
* For a -DBUILD_CONFIG=mysql_release build, the binary size is reduced by
~400kb.
* A raw -DCMAKE_BUILD_TYPE=Release reduces the binary size by ~1.4kb.
2. Compiler can better understand the intent of the code, thus it leads
to more optimization possibilities. Additionally it enabled detecting
unused variables that had an empty default constructor but not marked
so explicitly.
Particular change required following this patch in sql/opt_range.cc
result_keys, an unused template class Bitmap now correctly issues
unused variable warnings.
Setting Bitmap template class constructor to default allows the compiler
to identify that there are no side-effects when instantiating the class.
Previously the compiler could not issue the warning as it assumed Bitmap
class (being a template) would not be performing a NO-OP for its default
constructor. This prevented the "unused variable warning".
The easiest way to compile and test the server with UBSAN is to run:
./BUILD/compile-pentium64-ubsan
and then run mysql-test-run.
After this commit, one should be able to run this without any UBSAN
warnings. There is still a few compiler warnings that should be fixed
at some point, but these do not expose any real bugs.
The 'special' cases where we disable, suppress or circumvent UBSAN are:
- ref10 source (as here we intentionally do some shifts that UBSAN
complains about.
- x86 version of optimized int#korr() methods. UBSAN do not like unaligned
memory access of integers. Fixed by using byte_order_generic.h when
compiling with UBSAN
- We use smaller thread stack with ASAN and UBSAN, which forced me to
disable a few tests that prints the thread stack size.
- Verifying class types does not work for shared libraries. I added
suppression in mysql-test-run.pl for this case.
- Added '#ifdef WITH_UBSAN' when using integer arithmetic where it is
safe to have overflows (two cases, in item_func.cc).
Things fixed:
- Don't left shift signed values
(byte_order_generic.h, mysqltest.c, item_sum.cc and many more)
- Don't assign not non existing values to enum variables.
- Ensure that bool and enum values are properly initialized in
constructors. This was needed as UBSAN checks that these types has
correct values when one copies an object.
(gcalc_tools.h, ha_partition.cc, item_sum.cc, partition_element.h ...)
- Ensure we do not called handler functions on unallocated objects or
deleted objects.
(events.cc, sql_acl.cc).
- Fixed bugs in Item_sp::Item_sp() where we did not call constructor
on Query_arena object.
- Fixed several cast of objects to an incompatible class!
(Item.cc, Item_buff.cc, item_timefunc.cc, opt_subselect.cc, sql_acl.cc,
sql_select.cc ...)
- Ensure we do not do integer arithmetic that causes over or underflows.
This includes also ++ and -- of integers.
(Item_func.cc, Item_strfunc.cc, item_timefunc.cc, sql_base.cc ...)
- Added JSON_VALUE_UNITIALIZED to json_value_types and ensure that
value_type is initialized to this instead of to -1, which is not a valid
enum value for json_value_types.
- Ensure we do not call memcpy() when second argument could be null.
- Fixed that Item_func_str::make_empty_result() creates an empty string
instead of a null string (safer as it ensures we do not do arithmetic
on null strings).
Other things:
- Changed struct st_position to an OBJECT and added an initialization
function to it to ensure that we do not copy or use uninitialized
members. The change to a class was also motived that we used "struct
st_position" and POSITION randomly trough the code which was
confusing.
- Notably big rewrite in sql_acl.cc to avoid using deleted objects.
- Changed in sql_partition to use '^' instead of '-'. This is safe as
the operator is either 0 or 0x8000000000000000ULL.
- Added check for select_nr < INT_MAX in JOIN::build_explain() to
avoid bug when get_select() could return NULL.
- Reordered elements in POSITION for better alignment.
- Changed sql_test.cc::print_plan() to use pointers instead of objects.
- Fixed bug in find_set() where could could execute '1 << -1'.
- Added variable have_sanitizer, used by mtr. (This variable was before
only in 10.5 and up). It can now have one of two values:
ASAN or UBSAN.
- Moved ~Archive_share() from ha_archive.cc to ha_archive.h and marked
it virtual. This was an effort to get UBSAN to work with loaded storage
engines. I kept the change as the new place is better.
- Added in CONNECT engine COLBLK::SetName(), to get around a wrong cast
in tabutil.cpp.
- Added HAVE_REPLICATION around usage of rgi_slave, to get embedded
server to compile with UBSAN. (Patch from Marko).
- Added #ifdef for powerpc64 to avoid a bug in old gcc versions related
to integer arithmetic.
Changes that should not be needed but had to be done to suppress warnings
from UBSAN:
- Added static_cast<<uint16_t>> around shift to get rid of a LOT of
compiler warnings when using UBSAN.
- Had to change some '/' of 2 base integers to shift to get rid of
some compile time warnings.
Reviewed by:
- Json changes: Alexey Botchkov
- Charset changes in ctype-uca.c: Alexander Barkov
- InnoDB changes & Embedded server: Marko Mäkelä
- sql_acl.cc changes: Vicențiu Ciorbaru
- build_explain() changes: Sergey Petrunia
The assertion failed in handler::ha_reset upon SELECT under
READ UNCOMMITTED from table with index on virtual column.
This was the debug-only failure, though the problem is mush wider:
* MY_BITMAP is a structure containing my_bitmap_map, the latter is a raw
bitmap.
* read_set, write_set and vcol_set of TABLE are the pointers to MY_BITMAP
* The rest of MY_BITMAPs are stored in TABLE and TABLE_SHARE
* The pointers to the stored MY_BITMAPs, like orig_read_set etc, and
sometimes all_set and tmp_set, are assigned to the pointers.
* Sometimes tmp_use_all_columns is used to substitute the raw bitmap
directly with all_set.bitmap
* Sometimes even bitmaps are directly modified, like in
TABLE::update_virtual_field(): bitmap_clear_all(&tmp_set) is called.
The last three bullets in the list, when used together (which is mostly
always) make the program flow cumbersome and impossible to follow,
notwithstanding the errors they cause, like this MDEV-17556, where tmp_set
pointer was assigned to read_set, write_set and vcol_set, then its bitmap
was substituted with all_set.bitmap by dbug_tmp_use_all_columns() call,
and then bitmap_clear_all(&tmp_set) was applied to all this.
To untangle this knot, the rule should be applied:
* Never substitute bitmaps! This patch is about this.
orig_*, all_set bitmaps are never substituted already.
This patch changes the following function prototypes:
* tmp_use_all_columns, dbug_tmp_use_all_columns
to accept MY_BITMAP** and to return MY_BITMAP * instead of my_bitmap_map*
* tmp_restore_column_map, dbug_tmp_restore_column_maps to accept
MY_BITMAP* instead of my_bitmap_map*
These functions now will substitute read_set/write_set/vcol_set directly,
and won't touch underlying bitmaps.
now we can afford it. Fix -Werror errors. Note:
* old gcc is bad at detecting uninit variables, disable it.
* time_t is int or long, cast it for printf's
main.derived_cond_pushdown: Move all 10.3 tests to the end,
trim trailing white space, and add an "End of 10.3 tests" marker.
Add --sorted_result to tests where the ordering is not deterministic.
main.win_percentile: Add --sorted_result to tests where the
ordering is no longer deterministic.
Tests were failing because in TIME_from_longlong_datetime_packed() GCC8
at -O2 assumed that tmp is always positive and used mul and shr while it
used imul and sar at -O1 (where tests passed). GCC8 used multiplication
(by 0x4ec4ec4ec4ec4ec5) and shift to implement division by 13. It could
assume that tmp is always positive, because the function starts with
`if (tmp < 0) tmp= -tmp;`
But this assumption breaks if tmp=0x8000000000000000;
This is invalid value and TIME_from_longlong_datetime_packed() should
never see it, garbage in - garbage out.
It was getting this invalid value because mroonga tried to convert a
NULL key part to MYSQL_TIME. If the key part value is NULL, datetime2
value of it happens to be bzero-ed, which is invalid binary datetime2
value.
The correct behavior is not to try to interpret the key part value, if
it is marked as NULL. But this minimal fix only covers the datetime2 type.
Storage engine independent support for column compression.
TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT,
VARCHAR and VARBINARY columns can be compressed.
New COMPRESSED column attribute added:
COMPRESSED[=<compression_method>]
System variables added:
column_compression_threshold
column_compression_zlib_level
column_compression_zlib_strategy
column_compression_zlib_wrap
Status variables added:
Column_compressions
Column_decompressions
Limitations:
- the only supported method currently is zlib
- CSV storage engine stores data uncompressed on-disk even if COMPRESSED
attribute is present
- it is not possible to create indexes over compressed columns.
If compiling a non DBUG binary with
-DDBUG_ASSERT_AS_PRINTF asserts will be
changed to printf + stack trace (of stack
trace are enabled).
- Changed #ifndef DBUG_OFF to
#ifdef DBUG_ASSERT_EXISTS
for those DBUG_OFF that was just used to enable
assert
- Assert checking that could greatly impact
performance where changed to DBUG_ASSERT_SLOW which
is not affected by DBUG_ASSERT_AS_PRINTF
- Added one extra option to my_print_stacktrace() to
get more silent in case of stack trace printing as
part of assert.
Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)
Changes:
- This caused some ABI changes
- lex_string_set now uses LEX_CSTRING
- Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
code
- Added item_empty_name and item_used_name to be able to distingush between
items that was given an empty name and items that was not given a name
This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
give the error.
TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
(as part of lower_case_table_names)
