The -Wconversion in GCC seems to be stricter than in clang.
GCC at least since version 4.4.7 issues truncation warnings for
assignments to bitfields, while clang 10 appears to only issue
warnings when the sizes in bytes rounded to the nearest integer
powers of 2 are different.
Before GCC 10.0.0, -Wconversion required more casts and would not
allow some operations, such as x<<=1 or x+=1 on a data type that
is narrower than int.
GCC 5 (but not GCC 4, GCC 6, or any later version) is complaining
about x|=y even when x and y are compatible types that are narrower
than int. Hence, we must rewrite some x|=y as
x=static_cast<byte>(x|y) or similar, or we must disable -Wconversion.
In GCC 6 and later, the warning for assigning wider to bitfields
that are narrower than 8, 16, or 32 bits can be suppressed by
applying a bitwise & with the exact bitmask of the bitfield.
For older GCC, we must disable -Wconversion for GCC 4 or 5 in such
cases.
The bitwise negation operator appears to promote short integers
to a wider type, and hence we must add explicit truncation casts
around them. Microsoft Visual C does not allow a static_cast to
truncate a constant, such as static_cast<byte>(1) truncating int.
Hence, we will use the constructor-style cast byte(~1) for such cases.
This has been tested at least with GCC 4.8.5, 5.4.0, 7.4.0, 9.2.1, 10.0.0,
clang 9.0.1, 10.0.0, and MSVC 14.22.27905 (Microsoft Visual Studio 2019)
on 64-bit and 32-bit targets (IA-32, AMD64, POWER 8, POWER 9, ARMv8).
Such CMake check is not relevant as the oldest supported gcc is 4.8 and
compiler issue was solved in gcc-4.6 already.
https://godbolt.org/z/7G64qo
cmp_data(): simplify code
Remove the bug-compatible crc32 algorithm variant that was added
to allow an upgrade from data files from big-endian systems where
innodb_checksum_algorithm=crc32 was used on MySQL 5.6
or MariaDB 10.0 or 10.1.
Affected users should be able to recompute page checksums using
innochecksum.
In MySQL 5.7, it was noticed that files are not portable between
big-endian and little-endian processor architectures
(such as SPARC and x86), because the original implementation of
innodb_checksum_algorithm=crc32 was not byte order agnostic.
A byte order agnostic implementation of innodb_checksum_algorithm=crc32
was only added to MySQL 5.7, not backported to 5.6. Consequently,
MariaDB Server versions 10.0 and 10.1 only contain the CRC-32C
implementation that works incorrectly on big-endian architectures,
and MariaDB Server 10.2.2 got the byte-order agnostic CRC-32C
implementation from MySQL 5.7.
MySQL 5.7 introduced a "legacy crc32" variant that is functionally
equivalent to the big-endian version of the original crc32 implementation.
Thanks to this variant, old data files can be transferred from big-endian
systems to newer versions.
Introducing new variants of checksum algorithms (without introducing
new names for them, or something on the pages themselves to identify
the algorithm) generally is a bad idea, because each checksum algorithm
is like a lottery ticket. The more algorithms you try, the more likely
it will be for the checksum to match on a corrupted page.
So, essentially MySQL 5.7 weakened innodb_checksum_algorithm=crc32,
and MariaDB 10.2.2 inherited this weakening.
We introduce a build option that together with MDEV-17957
makes innodb_checksum_algorithm=strict_crc32 strict again
by only allowing one variant of the checksum to match.
WITH_INNODB_BUG_ENDIAN_CRC32: A new cmake option for enabling the
bug-compatible "legacy crc32" checksum. This is only enabled on
big-endian systems by default, to facilitate an upgrade from
MariaDB 10.0 or 10.1. Checked by #ifdef INNODB_BUG_ENDIAN_CRC32.
ut_crc32_byte_by_byte: Remove (unused function).
legacy_big_endian_checksum: Remove. This variable seems to have
unnecessarily complicated the logic. When the weakening is enabled,
we must always fall back to the buggy checksum.
buf_page_check_crc32(): A helper function to compute one or
two CRC-32C variants.
The checks that used to be enabled by the flags
UNIV_AHI_DEBUG, UNIV_DDL_DEBUG, UNIV_DEBUG_FILE_ACCESSES
were already enabled in debug builds. So, there is no point
in setting these.
Only UNIV_ZIP_DEBUG is set independently of the debug build.
Allow WITH_INNODB_EXTRA_DEBUG to be set for non-debug builds as well.
Currently it only implies UNIV_ZIP_DEBUG, that is, extra validation
for operations on ROW_FORMAT=COMPRESSED tables.
page_zip_validate_low(): Allow the code to be built on non-debug server.
buf_LRU_block_remove_hashed(): Allow the code to be built without
WITH_INNODB_AHI.
- compile_flags already include from top CMakeLists.txt
- MY_CHECK_CXX_COMPILER_FLAG() accepts only one parameter
- output variable of MY_CHECK_CXX_COMPILER_FLAG() is have_CXX__Wa__nH
- same check for mariabackup
Based on contribution by satanson (PR#466).
Compiler optimizations were switched off due to
MySQL Bug #19424, #36366, #34297, due to an alleged compiler bug.
No proper analysis of code generation was done back then, thus proof of
a compiler bug is missing.
Even if there was a compiler bug 13 years ago, it could have been fixed.
Will wait and see if there are any complains or crashes
The InnoDB adaptive hash index is sometimes degrading the performance of
InnoDB, and it is sometimes disabled to get more consistent performance.
We should have a compile-time option to disable the adaptive hash index.
Let us introduce two options:
OPTION(WITH_INNODB_AHI "Include innodb_adaptive_hash_index" ON)
OPTION(WITH_INNODB_ROOT_GUESS "Cache index root block descriptors" ON)
where WITH_INNODB_AHI always implies WITH_INNODB_ROOT_GUESS.
As part of this change, the misleadingly named function
trx_search_latch_release_if_reserved(trx) will be replaced with the macro
trx_assert_no_search_latch(trx) that will be empty unless
BTR_CUR_HASH_ADAPT is defined (cmake -DWITH_INNODB_AHI=ON).
We will also remove the unused column
INFORMATION_SCHEMA.INNODB_TRX.TRX_ADAPTIVE_HASH_TIMEOUT.
In MariaDB Server 10.1, it used to reflect the value of
trx_t::search_latch_timeout which could be adjusted during
row_search_for_mysql(). In 10.2, there is no such field.
Other than the removal of the unused column TRX_ADAPTIVE_HASH_TIMEOUT,
this is an almost non-functional change to the server when using the
default build options.
Some tests are adjusted so that they will work with both
-DWITH_INNODB_AHI=ON and -DWITH_INNODB_AHI=OFF. The test
innodb.innodb_monitor has been renamed to innodb.monitor
in order to track MySQL 5.7, and the duplicate tests
sys_vars.innodb_monitor_* are removed.
The MariaDB 10.1 page_compression is incompatible with the Oracle
implementation that was introduced in MySQL 5.7 later.
Remove the Oracle implementation. Also remove the remaining traces of
MYSQL_ENCRYPTION.
This will also remove traces of PUNCH_HOLE until it is implemented
better. The only effective call to os_file_punch_hole() was in
fil_node_create_low() to test if the operation is supported for the file.
In other words, it looks like page_compression is not working in
MariaDB 10.2, because no code equivalent to the 10.1 os_file_trim()
is enabled.
Clean-up periodic mutex/rwlock waiters wake up. This was a hack needed to
workaround broken mutexes/rwlocks implementation. We must have sane
implementations now and don't need these anymore: release thread is
guaranteed to wake up waiters.
Removed redundant ifdef that has equivalent code in both branches.
Removed os0atomic.h and os0atomic.ic: not used anymore.
Clean-up unused cmake checks.
Contains also:
MDEV-10549 mysqld: sql/handler.cc:2692: int handler::ha_index_first(uchar*): Assertion `table_share->tmp_table != NO_TMP_TABLE || m_lock_type != 2' failed. (branch bb-10.2-jan)
Unlike MySQL, InnoDB still uses THR_LOCK in MariaDB
MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan)
enable tests that were fixed in MDEV-10549
MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan)
fix main.innodb_mysql_sync - re-enable online alter for partitioned innodb tables
Contains also
MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7
The failure happened because 5.7 has changed the signature of
the bool handler::primary_key_is_clustered() const
virtual function ("const" was added). InnoDB was using the old
signature which caused the function not to be used.
MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7
Fixed mutexing problem on lock_trx_handle_wait. Note that
rpl_parallel and rpl_optimistic_parallel tests still
fail.
MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan)
Reason: incorrect merge
MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan)
Reason: incorrect merge
