Compiling as C++ changes nothing semantically, but ensures that we don't
break C++ compatibility while also retaining C compatibility.
C++ compatibility is useful for tooling and additional diagnostics and
analyses.
- Any non-externally-visible declarations should be `static`.
- Casting away the `const` qualifier from pointers-to-const is
dangerous. All but one instance of this are now correct. The one
instance where we can't keep `const` is one where toxav code actually
writes to a chunk of memory marked as `const`. This code also assumes
4 byte alignment of data packets. I don't know whether that is a valid
assumption, but it's likely unportable, and *not* obviously correct.
- Replaced empty parameter lists with `(void)` to avoid passing
parameters to it. Empty parameter lists are old style declarations for
unknown number and type of arguments.
- Commented out (as `#if DHT_HARDENING` block) the hardening code that
was never executed.
- Minor style fix: don't use `default` in enum-switches unless the number
of enumerators in the default case is very large. In this case, it was
2, so we want to list them both explicitly to be warned about missing
one if we add one in the future.
- Removed the only two function declarations from nTox.h and put them
into nTox.c. They are not used outside and nTox is not a library.
- Don't cast between object and function pointers.
- Use standard compliant `__VA_ARGS__` in macros.
- Add explicit `__extension__` on unnamed union in struct (it's a GNU
extension).
- Remove ; after function definitions.
- Replace `const T foo = 3;` for integral types `T` with `enum { foo = 3 };`.
Folding integral constants like that as compile time constants is a GNU
extension. Arrays allocated with `foo` as dimension are VLAs on strictly
compliant C99 compilers.
- Replace empty initialiser list `{}` with zero-initialiser-list `{0}`.
The former is a GNU extension meaning the latter.
- Cast `T*` (where `T != void`) to `void *` in format arguments. While any
object pointer can be implicitly converted to and from `void *`, this
conversion does not happen in variadic function calls.
- Replace arithmetic on `void *` with arithmetic on `char *`. The former
is non-compliant.
- Replace non-`int`-derived types (like `uint16_t`, which is
`short`-derived) in bit fields with `int`-derived types. Using any type
other than `int` or `unsigned int` (or any of their aliases) in bit
fields is a GNU extension.
Added request_id.
request_id must be obtained with tox_generate_dns3_string, stored,
then passed to tox_decrypt_dns3_TXT when we want to decrypt the
received response.
