This commit fixes BEGIN, COMMIT, and ROLLBACK counters in the box.stat()
output. Before this commit, they always showed 0. Now, they report
the number of started, committed, and rolled back transactions,
respectively.

Closes #7583

NO_DOC=bug fix

Currently, if a snapshot contains some correct entries, but doesn't
include system spaces, Tarantool crashes with segmentation fault, or
for Debug build: void diag_raise(): Assertion `e != NULL' failed.
This happens because memtx_engine_recover_snapshot returns -1, while
diag is not set. Let's panic instead of a crash.

Closes #7800

NO_DOC=bugfix

We need this option to implement a basic MT-safe read view C API
in the EE repository.

Closes #7815

NO_DOC=internal
NO_CHANGELOG=internal
NO_TEST=will be added to the EE repository

We need the options to optionally disable tuple decompression in memtx.

Needed for #7815

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

memtx_read_view_opts contains the only flag include_temporary_tuples,
which is set to read_view_opts.enable_temporary_spaces. Let's drop this
intermediary structure and pass read_view_opts to the allocator instead.

NO_DOC=refactoring
NO_CHANGELOG=refactoring

needs_FOO looks awkward for a flag name. Let's rename the flags to
enable_FOO. The new names will also look better in conjunction with the
disable_decompression flag that will be added in the scope of #7815.

NO_DOC=internal
NO_TEST=internal
NO_CHANGELOG=internal

0xc1 isn't a valid MsgPack header, but it was allowed by mp_check.
As a result, msgpack.decode crashed while trying to decode it.
This commit updates the msgpuck library to fix this issue.

Closes #7818

NO_DOC=bug fix

So one can easily check current box status.

NO_DOC=minor change

Closes #7255

cord() can't be NULL anymore - it's created on demand if not created
explicitly with cord_create().

Follow-up #7814

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

We're planning to introduce a basic C API for user read views (EE-only).
Like all other box C API functions, the new API functions will use the
existing box error C API for reporting errors. The problem is that
a read view created using C API should be usable from user threads
(started with the pthread lib) while the box error C API doesn't work
in user threads, because those threads don't have the cord pointer
initialized (a diagnostic area is stored in a cord object).

To address this issue, let's create a new cord object automatically on
first use of cord() if it wasn't created explicitly. Automatically
created object is destroyed at thread exit (to achieve that, we use
the C++ RAII concept).

Closes #7814

NO_DOC=The C API documentation doesn't say anything about threads.
       Let's keep it this way for now. We're planning to introduce
       a new C API to work with threads in C modules. We'll update
       the doc when it's ready.

Closes #7797

NO_DOC=security fix
NO_TEST=security fix

getenv() return values cannot be trusted, because an attacker might set
them. For instance, we shouldn't expect, that getenv() returns a value
of some sane size.

Another problem is that getenv() returns a pointer to one of
`char **environ` members, which might change upon next setenv().

Introduce a wrapper, getenv_safe(), which returns the value only when
it fits in a buffer of a specified size, and copies the value onto the
buffer. Use this wrapper everywhere in our code.

Below's a slightly decorated output of `grep -rwn getenv ./src --include
*.c --include *.h --include *.cc --include *.cpp --include *.hpp
--exclude *.lua.c` as of 2022-10-14.
`-` marks invalid occurences (comments, for example),
`*` marks the places that are already guarded before this patch,
`X` mars the places guarded in this patch, and
`^` marks places fixed in the next commit:

NO_WRAP
```
* ./src/lib/core/coio_file.c:509:	const char *tmpdir = getenv("TMPDIR");
X ./src/lib/core/errinj.c:75: const char *env_value = getenv(inj->name);
- ./src/proc_title.c:202: * that might try to hang onto a getenv() result.)
- ./src/proc_title.c:241:	* is mandatory to flush internal libc caches on getenv/setenv
X ./src/systemd.c:54: sd_unix_path = getenv("NOTIFY_SOCKET");
* ./src/box/module_cache.c:300: const char *tmpdir = getenv("TMPDIR");
X ./src/box/sql/os_unix.c:1441: azDirs[0] = getenv("SQL_TMPDIR");
X ./src/box/sql/os_unix.c:1446: azDirs[1] = getenv("TMPDIR");
* ./src/box/lua/console.c:394: const char *envvar = getenv("TT_CONSOLE_HIDE_SHOW_PROMPT");
^ ./src/box/lua/console.lua:771: local home_dir = os.getenv('HOME')
^ ./src/box/lua/load_cfg.lua:1007: local raw_value = os.getenv(env_var_name)
X ./src/lua/init.c:575: const char *path = getenv(envname);
X ./src/lua/init.c:592: const char *home = getenv("HOME");
* ./src/find_path.c:77: snprintf(buf, sizeof(buf) - 1, "%s", getenv("_"));
```
NO_WRAP

Part-of #7797

NO_DOC=security

This patch fixes the issue described in issue #5310 when the tuple
format has more fields than the space format. This solution is more
general than the solution in 89057a21.

Follow-up #5310
Closes #4666

NO_DOC=bugfix

Since our diagnostics use the `__FILE__` macro, they provide absolute
paths, which is kind of redundant and inconsistent: replace them with
relative ones.

As for debugging information, replacing absolute paths with relative ones
also requires an extra command to tell the debugger where to find the
source files, which is not convenient for developers: provide a new
`DEV_BUILD` option (turned off by default), which replaces absolute paths
with relative ones in debugging information if turned off.

Strip the prefix map flags from compiler flags exported to tarantool via
`src/trvia/config.h`.

Closes #7808

NO_DOC=<verbosity>
NO_TEST=<verbosity>

Fixes bug with determination of debug build (tarantool/test-run#352).

NO_CHANGELOG=<internal submodule version update>
NO_TEST=<submodule version update>
NO_DOC=<submodule version update>

Setting hardening compiler flags is used in three places: default build,
static build and enterprise build — refactor it into a separate module.

Follow-up e6abe1c9

NO_CHANGELOG=refactoring
NO_DOC=refactoring
NO_TEST=refactoring

e6abe1c9 passes compiler flags to dependencies via a `<project>_build` macro
parameter, which is, firstly, inconvenient, and, secondly, as a result, not
all dependencies got the required compiler flags passed: use global
variables instead and pass these flags to skipped dependencies.

Follow-up e6abe1c9

NO_CHANGELOG=refactoring
NO_DOC=refactoring
NO_TEST=refactoring

`add_compile_flags` macro relied on undefined behaviour: instead of
unsetting the `_lang` and `_flag` variables, it tried to unset their
values — fix this.

NO_CHANGELOG=build
NO_DOC=build
NO_TEST=build

Add missing .gitignore entry for autogenerated .lua.c translation units
located in <third_party/lua> directory.

Follows up #7593

NO_DOC=.gitignore
NO_TEST=.gitignore
NO_CHANGELOG=.gitignore

Signed-off-by: Igor Munkin <imun@tarantool.org>

If we raise different errors in case of entering an invalid password and
entering the login of a non-existent user during authorization, it will
open the door for an unauthorized person to enumerate users.
So let's unify raised errors in the cases described above.

Closes #tarantool/security#16

NO_DOC=security fix

Information about test code coverage is useful on code review.
This patch enables code coverage job in default ci.

NO_CHANGELOG=not a user-visible change
NO_DOC=not a user-visible change
NO_TEST=ci

This is a straightforward patch that makes the read view iterator struct
fixed-size so that it can be allocated on stack. This is a pre-requisite
for the raw C API for read views: the function that creates an iterator
should allocate no memory.

Closes #7813

NO_DOC=refactoring
NO_TEST=refactoring
NO_CHANGELOG=refactoring

At the moment we are not yet compatible with readline
support inside of Tarantool console. Diagnose that situation
at the moment debugger started and bail out.

NO_TEST=interactive
NO_DOC=Markdown updated

NO_TEST=see it elsewhere

Part of #7593

@TarantoolBot document
Title: Console debugger for Lua

Console debugger luadebug.lua
==============================

Module `luadebug.lua` is available as console debugger of Lua scripts.
It's activated via:

```
local debugger = require 'luadebug'
debugger()
```

Originally we have used 3rd-party code from slembcke/debugger.lua but
significantly refactored since then.

Currently available console shell commands are:
```
    c|cont|continue
    - continue execution
    d|down
    - move down the stack by one frame
    e|eval $expression
    - execute the statement
    f|finish|step_out
    - step forward until exiting the current function
    h|help|?
    - print this help message
    l|locals
    - print the function arguments, locals and upvalues
    n|next|step_over
    - step forward by one line (skipping over functions)
    p|print $expression
    - execute the expression and print the result
    q|quit
    - exit debugger
    s|st|step|step_into
    - step forward by one line (into functions)
    t|trace|bt
    - print the stack trace
    u|up
    - move up the stack by one frame
    w|where $linecount
    - print source code around the current line
```

Console debugger `luadebug.lua` allows to see sources of builtin
Tarantool module (e.g. `@builtin/datetime.lua`), and it uses new
function introduced for that purpose `tarantool.debug.getsources()`,
one could use this function in any external GUI debugger (i.e. vscode
or JetBrains) if need to show sources of builtin modules while they
have been debugged.

> Please see third_party/lua/README-luadebug.md for a fuller description
> of an original luadebug.lua implementation.

Created luatest test for interactive debugger luadebug.lua.
We use separate debug-target.lua for execution under
control of debugger session.

NO_DOC=test
NO_CHANGELOG=test

Number of 'call' hook invocations is always greater than
number of 'return' hook events. (i.e. ffi functions does use
`call` but there is no `return`. Same is for builtin functions
like `assert` or `error`).

We count number of stack frames available, and stop once
level is once again less or equal to the necessary one.
Math.huge is used to stop on each line (trace mode).

NO_CHANGELOG=internal
NO_DOC=internal
NO_TEST=internal

Do not use non-standard DBG_NOCOLOR, but use NO_COLOR [^1]
for disabling color output on terminals.

[^1]: https://no-color.org/

NO_DOC=later
NO_CHANGELOG=internal
NO_TEST=internal

Show debugger header only when repl is called.

NO_TEST=bugfix
NO_DOC=bugfix
NO_CHANGELOG=bugfix

Create command matcher and help map using convenient
builder function.

Commands described in a form:
```
    {'f.inish|step_out', 'step out', cmd_finish},
    {'p.rint $expression', 'execute the expression', cmd_print},
```
where we could introduce multiple aliases, commands with arguments,
commands descriptions and function handlers.

NO_DOC=internal
NO_CHANGELOG=internal
NO_TEST=internal

- refactor setmetatable usage to be more idiomatic;
- get rid of hardcode of `luadebug.lua` and use DEBUGGER
  instead. It will be necessary later for controlling
  of a name displayed by shell;
- refactor colored output facilities.

NO_TEST=refactoring
NO_DOC=refactoring
NO_CHANGELOG=refactoring

Get rid of all irrelevant for the Tarantool code:
- branches of code for non-LuaJIT interpreter;
- LuaJIT, but Windows-specific code;
- luadebug.lua (former debugger.lua) readline functions
  were incompatible with Tarantool console readline,
  so disable it entirely;
- Also fixed multiple luacheck warnings.

NO_DOC=refactoring
NO_CHANGELOG=refactoring
NO_TEST=refactoring

Extend Tarantool kernel internal API with the call
`tarantool.debug.getsources()` to allow to retrieve sources
of a Tarantool `builtin/*` modules to show them in the
debugger shell.

Created simple luatest script for checking consistency
of a values returned from `require 'tarantool'.debug.getsources()`
and an ctual script file content we expected to receive.

NO_DOC=see future commit
NO_CHANGELOG=see future commit

Enable automatical visualization of current context
after every next debugger step - so called "autolisting".

This supposedly resemble lldb behaviour, which is simplifying
debugging in CHUI.

NO_DOC=internal
NO_CHANGELOG=internal
NO_TEST=internal

Attempt to better format style of the imported
luadebug.lua (formerly known as debugger.lua)

NO_DOC=refactoring
NO_CHANGELOG=rafactoring
NO_TEST=refactoring

Use 3rd-party module https://github.com/slembcke/debugger.lua
as a basis for our debugger CLI shell, rename it to
luadebug.lua to avoid collision with vscode and JetBrains
debugger helper scripts.

NO_DOC=yet
NO_CHANGELOG=yet
NO_TEST=yet

The _vfunc system space is the sysview for the _func system space.
However, the _vfunc format is different from the _func format. This
patch makes the _vfunc format the same as the _func format.

Closes #7822

NO_DOC=bugfix

Allocation of URI parameters and their values dynamic arrays is done
inefficiently: they are reallocated each time a new parameter or parameter
value is added — grow them exponentially instead.

`struct uri_param` and `struct uri` are exposed in Lua via FFI
(see src/lua/uri.lua): add warnings about the necessity of reflecting
changes to them in `ffi.cdecl`.

Closes #7155

NO_DOC=optimization
NO_TEST=optimization

We used to ignore timezone difference (in `tzoffset`) for
datetime subtraction operation:

```
tarantool> datetime.new{tz='MSK'} - datetime.new{tz='UTC'}
---
- +0 seconds
...

tarantool> datetime.new{tz='MSK'}.timestamp -
           datetime.new{tz='UTC'}.timestamp
---
- -10800
...
```

Now we accumulate tzoffset difference in the minute component
of a resultant interval:

```
tarantool> datetime.new{tz='MSK'} - datetime.new{tz='UTC'}
---
- -180 minutes
...
```

Closes #7698

NO_DOC=bugfix

We did not take into consideration the fact that
as result of date/time arithmetic we could get
in a different timezone, if DST boundary has been
crossed during operation.

```
tarantool> datetime.new{year=2008, month=1, day=1,
			tz='Europe/Moscow'} +
	   datetime.interval.new{month=6}
---
- 2008-07-01T01:00:00 Europe/Moscow
...
```

Now we resolve tzoffset at the end of operation if
tzindex is not 0.

Fixes #7700

NO_DOC=bugfix

In PR #7791 the coverage stuff is slightly updated. The changes are
related to excluding some directories where the coverage will not be
calculated. The patch itself is straightforward enough, but I can see
the problems with uploading the results to coveralls.io:

NO_WRAP
    Using lcov file: ./coverage.info
    FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory

    <--- Last few GCs --->

    [2683200:0x327c000]    27836 ms: Scavenge 2033.4 (2038.7) -> 2033.2 (2044.2) MB, 6.8 / 0.0 ms  (average mu = 0.258, current mu = 0.243) allocation failure
    [2683200:0x327c000]    27854 ms: Scavenge 2036.7 (2044.2) -> 2037.1 (2044.4) MB, 15.6 / 0.0 ms  (average mu = 0.258, current mu = 0.243) allocation failure
    [2683200:0x327c000]    27871 ms: Scavenge 2037.2 (2044.4) -> 2036.7 (2055.9) MB, 17.1 / 0.0 ms  (average mu = 0.258, current mu = 0.243) allocation failure

    <--- JS stacktrace --->

    ==== JS stack trace =========================================

        0: ExitFrame [pc: 0x140dc19]
    Security context: 0x2481918808d1 <JSObject>
        1: encode(aka encode) [0x23ec5e514a11] [/opt/actions-runner/_work/_actions/coverallsapp/github-action/v1.1.2/node_modules/qs/lib/utils.js:~118] [pc=0x193ecd3d5d82](this=0x35d34e4804b1 <undefined>,0x1e5895380119 <Very long string[60387428]>)
        2: stringify(aka stringify) [0x23ec5e5174c9] [/opt/actions-runner/_work/_actions/coverallsapp/github-action/v1.1.2/n...

     1: 0xa1a640 node::Abort() [/opt/actions-runner/externals/node12/bin/node]
     2: 0xa1aa4c node::OnFatalError(char const*, char const*) [/opt/actions-runner/externals/node12/bin/node]
     3: 0xb9a62e v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [/opt/actions-runner/externals/node12/bin/node]
     4: 0xb9a9a9 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [/opt/actions-runner/externals/node12/bin/node]
     5: 0xd57c25  [/opt/actions-runner/externals/node12/bin/node]
     6: 0xd582b6 v8::internal::Heap::RecomputeLimits(v8::internal::GarbageCollector) [/opt/actions-runner/externals/node12/bin/node]
     7: 0xd64b75 v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector, v8::GCCallbackFlags) [/opt/actions-runner/externals/node12/bin/node]
     8: 0xd65a25 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [/opt/actions-runner/externals/node12/bin/node]
     9: 0xd670cf v8::internal::Heap::HandleGCRequest() [/opt/actions-runner/externals/node12/bin/node]
    10: 0xd15b35 v8::internal::StackGuard::HandleInterrupts() [/opt/actions-runner/externals/node12/bin/node]
    11: 0x1071176 v8::internal::Runtime_StackGuard(int, unsigned long*, v8::internal::Isolate*) [/opt/actions-runner/externals/node12/bin/node]
    12: 0x140dc19  [/opt/actions-runner/externals/node12/bin/node]
NO_WRAP

I have tried to use the latest version of the action (1.1.3), but I have
got the same issue.

It looks like it is a `coverallsapp/github-action` issue due to issue
in JavaScript due to inefficient amount of memory. The corresponding
bug [1] was filed against the repo.

So I suggest switching to the console utility `coveralls-lcov`. I did
some internal testing and it works fine.

[1] https://github.com/coverallsapp/github-action/issues/133

Fixes tarantool/tarantool-qa#278

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci