Implemented readline history and autocomplete by reusing
readline facilities of Tarantool console. They used to be
being hidden once Lua 'console' module is loaded. With c432e9e9
(lua: don't use public module name as internal one), now they
are available as 'console.lib'.

Closes #7738

NO_TEST=covered by refactored console_debugger_session_test.lua

@TarantoolBot document
Title: proper readline support in readline

Similar to tarantool interactive console, tdbg now uses readline
for its shell. It enables handier input editing, command history
and so on.

`console_debugger_session_test.lua` can be simplified and made more
stable with interactive_tarantool helper. With the new
`read_untill_prompt()` helper function, dbgr prompt can be used as
end-of-output marker instead of '...' in yaml-outputting main console.
This way, popen results are unambiguous and no retries are required.
At the same time, dbgr prompt is now expected with every result, thus
there is no need for an extra check. But `continue` command usually
reaches the end of the script and exits debugger, thus
'<END_OF_EXECUTION>' marker was introduced.
Empty stderr and header check were moved to interactive_tarantool helper.
This patch breaks the test without debugger readline support patch,
that is next in the patchset.

Part of #7738

NO_CHANGELOG=test refactoring
NO_DOC=test refactoring

The following changes were applied to `interactive_tarantool` helper
to adapt it for debugger tests:
* compared commands are now stripped from tabs and color codes too
* now each command independent of control symbols is being stripped
  before comparison in `execute_command()`
* created internal new function that is called from both `new()` and
  `new_debugger()`
* now user defined prompt can be set up from `new` and `new_debugger()`
* now there are several less typos in comments

Part of #7738

NO_CHANGELOG=test helper update
NO_DOC=test helper update
NO_TEST=test helper update

Runtime tuple formats are reusable, which means that a tuple format
returned by runtime_tuple_format_new may not be brand new, but actually
be used by a Lua object. As a result, if we call any function that may
trigger Lua GC between runtime_tuple_format_new and tuple_format_ref,
the tuple format may be deleted, leading to a use-after-free bug. This
is what happens in lbox_tuple_format_new. Fix this issue by moving the
runtime_tuple_format_new call after the Lua object allocation.

Closes #8889

NO_DOC=bug fix
NO_TEST=difficult to reproduce, found by ASAN

Closes #8801

@TarantoolBot document
Title: Document `box.session.new`

The new function creates a new session given a table of options:

 - `type`: string, optional. Default: "binary". [Type][session-type] of
   the new session. Currently, only "binary" is supported, which creates
   a new IPROTO session.

 - `fd`: number, mandatory. File descriptor number (fd) to be used for
   the new connection input-output. The fd must refer to a [socket] and
   be switched to the [non-blocking mode][socket-nonblock] but this
   isn't enforced, i.e. the user may pass an invalid fd, in which case
   the connection won't work as expected.

 - `user`: string, optional. Default: "guest". Name of the user to
   authenticate the new session as. Note, this doesn't prevent the other
   end to perform explicit [authentication].

 - `storage`: table, optional. Default: empty table. Initial value of
   the [session-local storage][session-storage].

On success, `box.session.new` takes ownership of the `fd` and returns
nothing. On failure, an error is raised.

Possible errors:
 - Invalid option value type.
 - `fd` isn't specified or has an invalid value.
 - `box.cfg` wasn't called.
 - `user` doesn't exist.

Example:

The code below creates a TCP server that accepts all incoming
IPROTO connections on port 3301, authenticates them as 'admin'
and sets the session-local storage to `{foo = 'bar'}`.

```lua
box.cfg()
require('socket').tcp_server('localhost', 3301, function(s)
    box.session.new({
        type = 'binary',
        fd = s:fd(),
        user = 'admin',
        storage = {foo = 'bar'},
    })
    s:detach()
end)
```

Notes:
- `box.cfg` must be called before using `box.session.new` to start
  IPROTO threads. Setting [`box.cfg.listen`][box-cfg-listen] isn't
  required though.
- The socket object must be detached after passing its fd to
  `box.session.new`, otherwise the fd would be closed on Lua garbage
  collection.

[authentication]: https://www.tarantool.io/en/doc/latest/dev_guide/internals/iproto/authentication/
[box-cfg-listen]: https://www.tarantool.io/en/doc/latest/reference/configuration/#cfg-basic-listen
[session-storage]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/box_session/storage/
[session-type]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/box_session/type/
[socket]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/socket/
[socket-nonblock]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/socket/#socket-nonblock

Sometimes we need to submit a remote call over cbus without waiting for
the result or even yielding. The cbus_call_timeout function isn't apt
for that because it yields even if timeout is 0 and sets diag. Let's
introduce cbus_call_async that exits immediately after pushing the call
message to the remote thread.

NO_DOC=internal
NO_CHANGELOG=internal

Part of #8862

NO_DOC=this API is not marked as public, at least now

A set of testing helpers was added in commit 06ca83c9 ("test/config:
add several application script tests"). In particular, they allow to run
a tarantool instance with some default config file and write only
necessary config options in a test case.

In fact, if no options were set in the test, the config file was not
written. It is fixed in this commit and used in the next commit.

Part of #8862

NO_DOC=testing helper change
NO_CHANGELOG=see NO_DOC

Closes #8928

@TarantoolBot document
Title: Document `from_fd` net.box module function

The function takes a file descriptor number (fd) as its first argument
and a table of connection options as its second, optional argument. It
creates and returns a new connection object.

The fd should point to a socket and be switched to the non-blocking
mode, but this isn't enforced. If the fd is invalid, the connection may
not work as expected.

The functions takes the same options as [`connect`][net-box-connect].

The function takes the ownership of the fd, i.e. the fd must not be used
or closed after this function successfully returns.

Example:

The code below connects to a Tarantool instance at port 3301 using
the [`socket`][socket] module, then wraps the socket fd in a `net.box`
connection object.

```Lua
local net = require('net.box')
local socket = require('socket')

-- Connect a socket then wrap it in a net.box connection object.
local s = socket.tcp_connect('localhost', 3301)
assert(s ~= nil)
local conn = net.from_fd(s:fd(), {fetch_schema = false})
s:detach()

conn:call('box.schema.user.info')
conn:close()
```

[net-box-connect]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/net_box/#net-box-connect
[socket]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/socket/

Those are really nice helpers. Let's move them to the utils module so
that we can use them everywhere. Also, let's add some unit tests.

NO_DOC=refactoring
NO_CHANGELOG=refactoring

The check_param and check_param_table Lua helpers are defined in
box/lua/schema.lua but used across the whole code base. The problem is
we can't use them in files that are loaded before box/lua/schema.lua,
like box/lua/session.lua. Let's move them to a separate source file
lua/utils.lua to overcome this limitation. Also, let's add some tests.

NO_DOC=refactoring
NO_CHANGELOG=refactoring

* ci: support coveralls
* cmake: add code coverage support
* test: run flake8 static analysis via CMake
* test: fix E741 errors by pycodestyle
* test: fix E722 errors by pycodestyle
* test: fix E711 errors by pycodestyle
* test: fix E502 errors by pycodestyle
* test: fix E501 errors by pycodestyle
* test: fix E305 errors by pycodestyle
* test: fix E303 errors by pycodestyle
* test: fix E302 errors by pycodestyle
* test: fix E301 errors by pycodestyle
* test: fix E275 errors by pycodestyle
* test: fix E251 errors by pycodestyle
* test: fix E231 errors by pycodestyle
* test: fix E203 errors by pycodestyle
* test: fix E201 and E202 errors by pycodestyle
* test: suppress E131 errors by pycodestyle
* test: fix E128 errors by pycodestyle
* test: fix E122 errors by pycodestyle
* gdb: fix Python <assert> statement usage

NO_DOC=LuaJIT submodule bump
NO_TEST=LuaJIT submodule bump
NO_CHANGELOG=LuaJIT submodule bump

NO_DOC=seed corpus
NO_CHANGELOG=seed corpus
NO_TEST=seed corpus

NO_DOC=testing
NO_CHANGELOG=testing

NO_DOC=seed corpus
NO_CHANGELOG=seed corpus
NO_TEST=seed corpus

Examples of IPROTO decoding issues: #3900, #1928, #6781.
Patch adds a number of fuzzing tests that covers IPROTO decoding:

- xrow_decode_auth
- xrow_decode_begin
- xrow_decode_call
- xrow_decode_dml
- xrow_decode_id
- xrow_decode_raft
- xrow_decode_sql
- xrow_decode_watch
- xrow_greeting_decode

NO_DOC=testing
NO_CHANGELOG=testing

Now the default value of a tuple field can be computed as a result of a
function call.

Closes #8609

@TarantoolBot document
Title: Document functional default field values
Product: Tarantool
Since: 3.0
Root document: https://www.tarantool.io/en/doc/latest/reference/reference_lua/box_space/format/
Depends on: tarantool/doc#3520

The format clause contains, for each field, a definition within braces:
`{name='...',type='...'[,default=...][,default_func=...]}`,
where:

* (Optional) The `default_func` string value specifies the name of a
  function, that is used to generate a default value for the field. If
  `default_func` is set, the `default` value is used as the function
  argument. See [field default functions](https://www.tarantool.io/en/doc/latest/concepts/data_model/value_store/#field-default-functions).

---

Root document: https://www.tarantool.io/en/doc/latest/concepts/data_model/value_store/#constraint-functions

**Field default functions**

Stored Lua function can be used to generate a default value for the tuple
field. It can take one optional parameter, and must return exactly one
value. To create a field default function, use func.create with function
body. The function must not yield.

Example:

```lua
box.schema.func.create('random_point', {
    language = 'Lua',
    body = 'function(param) return math.random(param.min, param.max) end'
})

box.schema.space.create('test')
box.space.test:create_index('pk')
box.space.test:format({
    {name = 'id', type = 'integer'},
    {name = 'latitude', type = 'number',
     default_func = 'random_point', default = {min = -90, max = 90}},
    {name = 'longitude', type = 'number',
     default_func = 'random_point', default = {min = -180, max = 180}}
})
```

```lua
tarantool> math.randomseed(os.time())
---
...

tarantool> box.space.test:insert{1}
---
- [1, 56, 38]
...
```

This structure will be extended in the next commit.

Part of #8609

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

This call is redundant and does nothing. Constraints are destroyed in
space_cleanup_constraints(), which is called from space_create() and
space_delete(). Standalone tuples can't have initialized constraints.

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

User id instead of function id was erroneously used there.

NO_DOC=bugfix
NO_CHANGELOG=minor

The checks in box.schema.index.create() and box.schema.index.alter()
were case sensitive, also it was possible to insert incorrect index
options directly into `box.space._index`. Fixed by adding checks
to memtx_space_check_index_def() and vinyl_space_check_index_def().

Closes #8937

NO_DOC=bugfix

And remove unused index_def_check_xc().

As index_def_dup() never returns NULL anymore, change index_create() and
index_read_view_create() return type to `void` and update their callers.

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

The `__sanitizer_start_switch_fiber()` function takes a pointer as the
first argument to store the current fake stack if there is one (it is
necessary when stack-use-after-return detection is enabled). When leaving a
fiber definitely, NULL must be passed so that the fake stack is destroyed.

Before this patch, NULL was passed for dead fibers, however this is wrong
for dead fibers that are recycled and resumed. In such cases ASAN destroys
the fake stack, and the fiber crashes trying to use it in `fiber_yield()`
upon return from `coro_transfer()`.

Closes tarantool/tarantool-qa#321

NO_DOC=bugfix
NO_TEST=tested by test-release-asan workflow

_cluster on-replace trigger parses old and new tuples into
replica_def objects. One path handles the case of new_def != NULL.
The other assumes that old_def != NULL if new_def was NULL. This
is correct, because replace wouldn't happen if both tuples are
NULL. It would mean nothing changed.

Nonetheless coverity complained here that the old tuple could be
NULL even if the new one was NULL. The patch silences this warning
by adding an assert.

NO_DOC=refactor
NO_CHANGELOG=refactor
NO_TEST=not testable

box_set_instance_name() has a scoped guard to try to restore the
replication back to normal if the connection to master was
recreated to make the applier request a new name.

The guard calls box_restart_replication() which might throw
exceptions. But in this case it apparently can only happen in
theory with bootstrap strategy legacy + high connection quorum +
failing to gather this quorum. Also iostream creation might fail.

Iostream creation failure is not testable, and the legacy
bootstrap strategy is being deprecated at some point. So the
patch simply adds try-catch without a test as it is too much
effort for too little gain to bother. This should also calm down
the coverity reporter.

NO_DOC=bugfix/refactor
NO_CHANGELOG=hardly possible to observe this bug
NO_TEST=too hard to repro

Fuzzing test for LuaJIT generates random Lua programs and executes them.
We want to build a fuzzing test that will produce Lua programs that will
not contain semantic errors and will trigger as much as possible
components in LuaJIT.

This proposed patch introduces metrics that gathered after running the
test. LuaJIT metrics gathered using LuaJIT getmetrics module [1]. All
gathered metrics test will output after running with a finite number of
runs or finite duration of time (options `-runs` and `-max_total_time`)
or after sending SIGUSR1 to a test process.

```
$ ./build/test/fuzz/luaL_loadbuffer/luaL_loadbuffer_fuzzer -runs=1000

<snipped>

Done 1000 runs in 1 second(s)
Total number of samples: 1000
Total number of samples with errors: 438 (43%)
Total number of samples with recorded traces: 87 (8%)
Total number of samples with snap restores: 30 (3%)
Total number of samples with abort traces: 55 (5%)
```

1. https://www.tarantool.io/en/doc/latest/reference/tooling/luajit_getmetrics/#getmetrics-c-api

NO_CHANGELOG=testing
NO_DOC=testing

The function can't be called on an unconfigured instance because it
needs IPROTO threads up and running. Let's raise an error to avoid
a crash.

Since we have two other places where we need to raise the same error
(box.session.su and box.__index), let's introduce the new code
ER_UNCONFIGURED for this error.

Closes #8975

NO_DOC=bug fix

The `popen_new()` function may be called with inherit_fds = NULL,
nr_inherit_fds = 0. The lua/popen.c code actually does this.

It leads to the following memcpy() call.

```
memcpy(dst, NULL, 0);
```

According to the C11 standard (n1256, 7.21.1), the pointer argument
should have a valid value, which means pointing to some area in the
program's address space, not NULL. The standard doesn't make an
exception for a zero size array.

Personally I doubt that any memcpy() implementation attempts to
dereference the source pointer in case of a zero size, but it is my
assumption, while the standard is the standard.

The problem is found by Coverity.

Follows up #8926

NO_DOC=it is a bug
NO_CHANGELOG=this code is not released yet
NO_TEST=verified by existing test cases, which call popen.new() without
        the inherit_fds option

Closes #8802

@TarantoolBot document
Title: Deprecate box.session.push

The `box.session.push` Lua function and `box_session_push` C API
function are deprecated starting from Tarantool 3.0. Calling any
of these functions for the first time results in printing a warning
message to the log.

The new compat module option `box_session_push_deprecation` was
introduced to control whether the functions are still available.
With the old behavior, which is the default in Tarantool 3.0,
`box.session.push` is still available. With the new behavior,
any attempt to use it raises an exception.

(Please create https://tarantool.io/compat/box_session_push_deprecation)

We are planning to switch the compat option to the new behavior
starting from Tarantool 4.0 with the ability to revert to the
old behavior. Starting from Tarantool 5.0 we are planning to
drop `box.session.push` completely.

It lists the environment variables that are taken into account by the
config module.

Part of #8862

NO_DOC=reflected in https://github.com/tarantool/doc/issues/3544

The next commit needs to output a lot of environment variables, their
types in the config schema, defaults and so on. It looks much more
readable when formatted in the tabular form.

This commits adds a simple tabular formatter for this purpose.

Part of #8862

NO_DOC=the new module is internal
NO_CHANGELOG=see NO_DOC

Sometimes we need to know somethings about ancestor nodes during
processing of a current node.

Now, the `<schema node>.computed.annotations` table represents all the
annotations from the root of the schema down to the given schema node
merged into a flat table. If the same named annotation met several times
on the path, the descendant value is preferred.

This computed annotations table is available everywhere, where the
schema node is returned or passed as a callback's argument. For example,
in values of the `<schema>:pairs()` iterator and in the `validate()`
schema node's callback.

It will be used in one of the next commits this way:

```lua
for _, w in instance_config:pairs() do
    if w.schema.computed.annotations.enterprise_edition then
        <...>
    else
        <...>
    end
end
```

Part of #8862

NO_DOC=the schema module is internal, at least now
NO_CHANGELOG=see NO_DOC

Pin in cache the collation identifiers that are referenced by space format
and/or indexes, so that they can't be deleted.

Closes #4544

NO_DOC=bugfix

It was possible to delete a collation, which is in use by a key_def.

Part of #4544

NO_DOC=bugfix
NO_CHANGELOG=next commit

Since number type was introduced we can not assume if tuples are
equal by comparison then their sizes are equal too. So the place
the assumption is used is fixed.

Closes #8899

NO_DOC=bugfix

Getting rid of C++ exception is our long term goal. This commit removes
the exceptions from the IPROTO code as follows:

- Make iproto_set_msg_max return -1 instead of raising an exception
  on error. Update box_set_net_msg_max accordingly.
- Make box_process_auth return -1 instead of raising an exception on
  error. Move it along with box_process_vote (which never fails) to
  the extern "C" namespace.
- Remove try/catch from iproto_connection_on_input, tx_process_misc,
  tx_process_connect. Use a label instead.
- Panic instead of raising an exception on an error starting an IPROTO
  thread in iproto_init. It should be fine because the function is
  called only at startup and shouldn't normally fail.
- Remove try/catch from iproto_do_cfg_f. It turns out that this function
  never fails so we don't even need to use an error label.
- Drop iproto_do_cfg_crit and move the assertion to iproto_do_cfg
  because this function should never fail and so we don't need the
  wrapper.

After this commit, the only exception-handling piece of code left in
IPROTO is tx_process_replication. Dropping it would entail patching
replication, relay, and recovery code so it was postponed.

NO_DOC=code cleanup
NO_TEST=code cleanup
NO_CHANGELOG=code cleanup

The buffer is unlimited so allocations from it never fail. Even if
decide to add a hard limit some day, it's better to do it somewhere in
one place to simplify testing so the dropped code isn't going to be
needed.

NO_DOC=code cleanup
NO_TEST=code cleanup
NO_CHANGELOG=code cleanup

The mempools are unlimited so allocations from them never fail. Even if
we decide to add a hard limit some day, it's better to do it somewhere
in one place to simplify testing so the dropped code isn't going to be
needed.

NO_DOC=code cleanup
NO_TEST=code cleanup
NO_CHANGELOG=code cleanup

malloc isn't supposed to fail so let's use xmalloc helper in rmean_new
and get rid of allocation failure paths.

NO_DOC=code cleanup
NO_TEST=code cleanup
NO_CHANGELOG=code cleanup

The new function is a wrapper around the socketpair system call.
It takes the same arguments as the socket constructor and returns
two socket objects representing the two ends of the newly created
socket pair on success.

It may be useful for establishing a communication channel between
related processes.

Closes #8927

@TarantoolBot document
Title: Document new socket functions

Two socket module functions and one socket object method were added to
Tarantool 3.0:

- `socket.from_fd(fd)`: constructs a socket object from the file
  descriptor number. Returns the new socket object on success. Never
  fails. Note, the function doesn't perform any checks on the given
  file descriptor so technically it's possible to pass a closed file
  descriptor or a file descriptor that refers to a file, in which case
  the new socket object methods may not work as expected.

- `socket:detach()`: like `socket:close()` but doesn't close the socket
  file descriptor, only switches the socket object to the closed state.
  Returns nothing. If the socket was already detached or closed, raises
  an exception.

  Along with `socket.from_fd`, this method may be used for transferring
  file descriptor ownership from one socket to another:

  ```Lua
  local socket = require('socket')
  local s1 = socket('AF_INET', 'SOCK_STREAM', 'tcp')
  local s2 = socket.from_fd(s1:fd())
  s1:detach()
  ```

- `socket.socketpair(domain, type, proto)`: a wrapper around the
  [`socketpair`][1] system call. Returns two socket objects representing
  the two ends of the new socket pair on success. On failure, returns
  nil and sets [`errno`][2].

  Example:

  ```Lua
  local errno = require('errno')
  local socket = require('socket')
  local s1, s1 = socket.socketpair('AF_UNIX', 'SOCK_STREAM', 0)
  if not s1 then
      error('socketpair: ' .. errno.strerror())
  end
  s1:send('foo')
  assert(s2:recv() == 'foo')
  s1:close()
  s2:close()
  ```

[1]: https://man7.org/linux/man-pages/man2/socketpair.2.html
[2]: https://www.tarantool.io/en/doc/latest/reference/reference_lua/errno/