66832e3a introduced change that prints core dumps in very detailed
format. That's completely out of user-friendliness but serves as a
measure for debugging hard-reproducible bugs.
The proper way to implement this:
1. it must be controlled by command-line and environment variable;
2. detailed traces must be default for buildbots only, for user
invocations normal stack traces should be printed.
Options for control are: MTR_PRINT_CORE and --print-core that accept
the following values:
no Don't print core
short Print stack trace of failed thread
medium Print stack traces of all threads
detailed Print all stack traces with debug context
custom:<code> Use debugger commands <code> to print stack trace
Default setting is: short (see env_or_default() call in pre_setup())
For environment variable wrong values are silently ignored (falls back
to default setting, see env_or_default()).
Command-line option --print-core (or -C) overrides environment
variable. Its default value is 'short' if not specified explicitly
(same env_or_default() call in pre_setup()). Explicit values are
checked for validity.
--print-method option can specify by which debugger we print
cores. For Windows there is only one choice: cdb. For Unix the values
are: gdb, dbx, lldb, auto. Default value is: auto
In 'auto' we try to use all possible debuggers until success.
bt full - to include args and locals.
set print sevenbit on
- it is more useful to be able to see the exact bytes
(in case something is dumped as a string and not hexadecimal digits)
set print static-members off
- there are many interesting (non-const) static members
set frame-arguments all
- even non-printables are useful to see.
Let's make our bb logs give a little bit more detail on those
hard to reproduce bugs.
Tests on rhel7's gdb-7.6.1-120.el7
Added --result-file option, which will produce var/mtr-results.txt
Output has a simple format:
<tag> : <value> for general info on test run
{
<tag> : <value>
....
} for each test
Output from failed tests are included but may be truncated.
See WL for more details.
- output callstacks from crash using cdb debugger which is part
of "Debugging Tools for Windows". Output other interesting
information - function parameters, possibly source code fragment
and other goodies of "!analyze" cdb extension.
SIGABRT is sent to relevant processes after a timeout
client/mysqltest.cc:
Fixed signal handlers to mysqltest actually dumps core
mysql-test/lib/My/CoreDump.pm:
Added support for dbx
mysql-test/lib/My/SafeProcess.pm:
Added dump_core to force process to dump core
mysql-test/lib/My/SafeProcess/safe_process.cc:
Traps SIGABRT and sends this on to child
mysql-test/mysql-test-run.pl:
When test times out, force core dumps on mysqltest and servers
Post-push fixes making it work on pushbuild's valgrind host, and clarifying the output.
mysql-test/lib/My/CoreDump.pm:
- Improved parsing of mtr output so that it works on pushbuild's "valgrind" host.
- Added stack trace for the thread that coredumped, to make output more readable when there are many threads.
- Added explanation of what the output consists of.
- Added early removal of temp file.
