Commit Graph

42 Commits

Author SHA1 Message Date
Nico Weber
9fb0de1cfe AK: Mark Error nodiscard
...instead of manually marking all methods returning Error nodiscard.

No real behavior change.
2023-07-12 17:03:07 +02:00
Sam Atkins
c140b67be3 AK: Verify that we don't call Error::from_errno(0)
We shouldn't ever make an Error if there wasn't actually an error. :^)
2023-05-28 05:51:27 -06:00
Ali Mohammad Pur
7e6341587b AK+Everywhere: Disallow Error::from_string_view(FooString)
That pattern seems to show up a lot in code written by people that
aren't intimately familiar with the lifetime model of Error and Strings.
This commit makes the compiler detect it and present a more helpful
diagnostic than "garbage string at runtime".
2023-04-28 05:55:20 +02:00
Tim Schumacher
332b253a47 AK: Provide is_errno for Kernel Errors
It wouldn't make much sense on its own (as the Kernel only has errno
Errors), but it's an easy fix for not having to ifdef away every single
usage of `is_errno` in code that is shared between Userland and Kernel.
2023-02-10 12:15:02 +01:00
Tim Schumacher
be25602d44 AK: Allow explicitly copying Errors in the Kernel 2023-02-10 12:15:02 +01:00
Tim Schumacher
cc8874b5aa AK: Fix a linting issue in Error.h
I'm not sure why, but `clang-format` gets unhappy if we touch the
adjacent line.
2023-02-10 12:15:02 +01:00
Liav A
048fb2c204 AK: Disallow returning of string literals for errors in kernel code
This code should not be used in the kernel - we should always propagate
proper errno codes in case we need to return those to userland so it
could decode it in a reasonable way.
2023-02-10 09:14:20 +00:00
Liav A
ab27fce86f AK: Add a new method to propagate errno while printing errors in Kernel
This new method is meant to be used in both userspace and kernel code.
The idea is to allow printing of a verbose message and then returning an
errno code which is the proper mechanism for kernel code because we
should almost always assume that such error will be propagated back to
userspace in some way, so the userspace code could reasonably decode it.

For userspace code however, this new method is meant to be a simple
wrapper for Error::from_string_view, because for most invocations, it's
much more useful to have a verbose & literal error than a errno code, so
we simply ignore that errno code completely in such context.
2023-02-10 09:14:20 +00:00
Timothy Flynn
8eb3d79129 AK: Disallow implicitly copying Error and ErrorOr instances
In the rare cases that a copy is actually needed, the Error::copy
factory will suffice.
2023-02-10 09:08:52 +00:00
Timothy Flynn
945f392392 AK: Add an explicit Error factory to copy an existing error
As of now, there is a default copy constructor on Error. A future commit
will make this non-public to prevent implicit copies, so to prepare for
that, this adds a factory for the few cases where a copy is really
needed.
2023-02-10 09:08:52 +00:00
Ben Wiederhake
3281050359 Everywhere: Remove "LibC/" includes, add lint-rule against it 2023-01-07 10:01:37 -07:00
Sam Atkins
feb0eb9309 AK: Fix constructing ErrorOr from ErrorOr of a related type
Mark other ErrorOr types as friends, and fix a typo in the &&
constructor, so that we can create an ErrorOr<Core::Object> from an
ErrorOr<GUI::Widget>. Also, add some requires() clauses to these
constructors so the error messages are clearer.
2022-12-28 22:34:00 -05:00
Nico Weber
8932b28b8a AK: Mark Error::from_ functions as [[nodiscard]]
Prevents mistakes like the one fixed in #16672.
2022-12-26 13:56:13 -05:00
Timothy Flynn
4b4b15adb1 AK: Rearrange Error's members to reduce its size by 8 bytes
This shrinks sizeof(Error) from 32 bytes to 24 bytes, which in turn will
shrink sizeof(ErrorOr<T>) by the same amount (in cases where sizeof(T)
is less than sizeof(Error)).
2022-12-22 14:13:56 -05:00
Ali Mohammad Pur
1cc8cdcd23 AK: Add a Error::__jakt_from_string_literal(StringView) factory function
Note that Jakt only allows StringView creation from string literals, so
none of the invariants in the class are broken by this (if used only
from within Jakt).
2022-12-11 20:44:54 +03:30
Ali Mohammad Pur
537924a8d0 AK: Let ErrorOr<T, E> expose its result/error types
`ErrorOr<T, E>::ResultType` can now refer to `T`.
2022-12-11 20:44:54 +03:30
Ali Mohammad Pur
58252a7684 AK: Elaborate the Error constructors a bit
The old constraints were making clang mad, so express them in a less
complex way.
2022-12-11 20:44:54 +03:30
Linus Groh
d26aabff04 Everywhere: Run clang-format 2022-12-03 23:52:23 +00:00
Andreas Kling
ae3ffdd521 AK: Make it possible to not using AK classes into the global namespace
This patch adds the `USING_AK_GLOBALLY` macro which is enabled by
default, but can be overridden by build flags.

This is a step towards integrating Jakt and AK types.
2022-11-26 15:51:34 +01:00
Andrew Kaster
828441852f Everywhere: Replace uses of __serenity__ with AK_OS_SERENITY
Now that we have OS macros for essentially every supported OS, let's try
to use them everywhere.
2022-10-10 12:23:12 +02:00
Timothy Flynn
e897008449 AK: Change ErrorOr to contain a Variant rather than inherit from it
GCC seems to get tripped up over this inheritance when converting from
an ErrorOr<StringView> to the partially specialized ErrorOr<void>. See
the following snippet:

    NEVER_INLINE ErrorOr<StringView> foo()
    {
        auto string = "abc"sv;
        outln("{:p}", string.characters_without_null_termination());
        return string;
    }

    NEVER_INLINE ErrorOr<void> bar()
    {
        auto string = TRY(foo());
        outln("{:p}", string.characters_without_null_termination());

        VERIFY(!string.starts_with('#'));
        return {};
    }

    int main()
    {
        MUST(bar());
    }

On some machines, bar() will contain a StringView whose pointer has had
its upper bits set to 0:

    0x000000010cafd6f8
    0x000000000cafd6f8

I'm not 100% clear on what's happening in the default-generated Variant
destructor that causes this. Probably worth investigating further.

The error would also be alleviated by making the Variant destructor
virtual, but rather than that, let's make ErrorOr simply contain a
Variant rather than inherit from it.

Fixes #15449.
2022-10-07 18:21:40 +01:00
Lucas CHOLLET
42518867d7 AK: Make ErrorOr::error() const and return a const reference 2022-09-27 21:29:44 +01:00
sin-ack
e5f09ea170 Everywhere: Split Error::from_string_literal and Error::from_string_view
Error::from_string_literal now takes direct char const*s, while
Error::from_string_view does what Error::from_string_literal used to do:
taking StringViews. This change will remove the need to insert `sv`
after error strings when returning string literal errors once
StringView(char const*) is removed.

No functional changes.
2022-07-12 23:11:35 +02:00
Lucas CHOLLET
dad4716cc2 AK: Add Error::operator==(Error const&) 2022-06-09 22:08:04 +02:00
Sam Atkins
1a4dd47d5f AK: VERIFY inside release_value_but_fixme_should_propagate_errors()
While the code did already VERIFY that the ErrorOr holds a value, this
was done by Variant, so the error message was just that `has<T>()` is
false. This is less helpful than I would like, especially if backtraces
are not working and this is all you have to go on. Adding this extra
VERIFY means the assertion message (`!is_error()`) is easier to
understand.
2022-02-16 19:49:41 -05:00
Andreas Kling
452a5531be AK+LibMain: Improve formatter for AK::Error in userspace
Print the full associated string metadata by default (if available.)
2021-12-20 21:13:42 +01:00
sin-ack
69ef211925 Kernel+LibC: Move errno definitions to Kernel/API/POSIX
This fixes at least half of our LibC includes in the kernel. The source
of truth for errno codes and their description strings now lives in
Kernel/API/POSIX/errno.h as an enumeration, which LibC includes.
2021-12-16 22:21:35 +03:30
Ben Wiederhake
208d85e707 AK+Tests: Use less space in ErrorOr 2021-12-16 09:32:51 +01:00
Ben Wiederhake
6f37510a71 AK: Implement missing const getters in AK::Error, fix typo
Note that the return type for the non-const method error() changed. This
is most likely an accident, hidden by the fact that ErrorType typically
is Error.
2021-12-05 22:59:09 +01:00
Andreas Kling
4e530135d5 AK+LibSystem+LibMain: Add Error::from_syscall() for syscall failures
This creates an error that contains the name of the syscall that failed.
This allows error handlers to print out the name of the call if they
want to. :^)
2021-11-22 19:28:31 +01:00
Andreas Kling
216e21a1fa AK: Convert AK::Format formatting helpers to returning ErrorOr<void>
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
2021-11-17 00:21:13 +01:00
Andreas Kling
11aad74dce AK: Forward declare Error and ErrorOr in AK/Forward.h 2021-11-17 00:21:12 +01:00
Andreas Kling
7ee10c6926 AK: Add some more ways to construct Error and ErrorOr<T>
This is preparation for using Error in the kernel instead of KResult.
2021-11-08 00:36:35 +01:00
Andreas Kling
5e473a63d3 AK: Make Error.h pull in Try.h
Users of this API will want TRY().
2021-11-08 00:36:19 +01:00
Andreas Kling
e253cf694e AK: Allow subclassing Error 2021-11-08 00:35:27 +01:00
Andreas Kling
202950bb01 AK: Make Error and ErrorOr<T> work in Lagom as well :^)
ErrnoCode is not a thing outside __serenity__, so let's not make
assumptions about it existing.
2021-11-08 00:35:27 +01:00
Andreas Kling
2116620db8 AK: Add ErrorOr<T>::release_value_but_fixme_should_propagate_errors()
This is an alternative to ErrorOr<T>::release_value() that can be used
when converting code to signal that we're releasing the value without
error propagation as a way to move forward now.

This makes these cases much easier to find later on, once more paths for
error propagation are available.
2021-11-08 00:35:27 +01:00
Andreas Kling
e5dde37e24 AK: Bring AK::Error into the global namespace 2021-11-08 00:35:27 +01:00
Andreas Kling
c4edb9f6c2 AK: Add Error and ErrorOr<T>
The goal with these is to eventually replace AK::Result, KResult and
KResultOr<T> with something that works (and makes sense) in both kernel
and userspace.

This first cut of Error can be made from an errno code, or from a string
literal (StringView)
2021-11-08 00:35:27 +01:00
Andreas Kling
59cd181ed9 AK: Remove unused Error template 2020-04-21 16:19:18 +02:00
Andreas Kling
94ca55cefd Meta: Add license header to source files
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.

For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.

Going forward, all new source files should include a license header.
2020-01-18 09:45:54 +01:00
Robin Burchell
7dd25141cd Add Error<>
Put simply, Error<> is a way of forcing error handling onto an API user.

Given a function like:

    bool might_work();

The following code might have been written previously:

    might_work(); // but what if it didn't?

The easy way to work around this is of course to [[nodiscard]] might_work.
But this doesn't work for more complex cases like, for instance, a
hypothetical read() function which might return one of _many_ errors
(typically signalled with an int, let's say).

    int might_read();

In such a case, the result is often _read_, but not properly handled. Like:

    return buffer.substr(0, might_read()); // but what if might_read returned an error?

This is where Error<> comes in:

    typedef Error<int, 0> ReadError;
    ReadError might_read();

    auto res = might_read();
    if (might_read.failed()) {
        switch (res.value()) {
        case EBADF:
            ...
        }
    }

Error<> uses clang's consumable attributes to force failed() to be
checked on an Error instance. If it's not checked, then you get smacked.
2019-07-31 09:06:39 +02:00