tarantool / luajit / 13201246580 / 1

93%

tarantool/master: 93%

push

github

Handle all stack layouts in (delayed) TRACE vmevent.

Thanks to Sergey Bronnikov and Peter Cawley.

(cherry picked from commit b138ccfa9)

When recording a trace using a Lua code like
`repeat until `a >= 'b' > 'b'` a Lua error is encountered
(`attempt to compare string with nil`), which (along with
raising the error) causes an asynchronous trace abort.
The trace abort remains pending until the next reentrance to the
LuaJIT VM via `lj_vm_call()` or `lj_vm_pcall().

On handling abort LuaJIT is searching for the topmost Lua frame
on the stack, that was active when the trace abort happened,
it is needed to generate a better error message.
Unfortunately, because the abort was due to an error, and
the error was caught by a `lua_pcall` with an unspecified
error function (4th argument), the Lua frame that caused the abort
was already removed as part of error processing, so the search
cannot find it. Furthermore, in this particular case, there are
no Lua frames on the stack, which isn't something the search code
had considered possible.

Sergey Bronnikov:
* added the description and the test for the problem

Part of tarantool/tarantool#11055

5700 of 6035 branches covered (94.45%)

Branch coverage included in aggregate %.

21721 of 23442 relevant lines covered (92.66%)

2962997.97 hits per line