Methods marked as const should always only return Foo const&, never
Foo&. Previously, this only worked correctly with Foo, but not with
Foo&: If someone fetched a T const&, this would have been expanded
to Foo& const& which is just Foo&. Therefore, they were able to modify
the elements of the Vector, even though it was marked as const.
This commit fixes that by introducing VisibleType as an alias for
RemoveReference<T> and using it throughout Vector.
There are also other cases where we don't require a mutable reference
to the underlying type, only a const reference (for example in a find
operation). In these cases, we now also correctly expand the type
to Foo const&.
We have whittled away at the usages of these AK::Vector APIs in the
Kernel. This change disables them from being visible when building
the Kernel to make sure no new usages get added.
Previously, Vector::extend for a moved vector would move the other
vector into this vector if this vector was empty, thereby throwing away
existing allocated capacity. Therefore, this commit allows the move to
only happen if this vector's capacity is too small to fit the other
vector. This will also alleviate bugs where callers relied on the
capacity to never shrink with calls to unchecked_append, extend and the
like.
This mirrors the existence of append() for data pointers and is very
useful when the program needs to have a guarantee of no allocations,
as is necessary for real-time audio.
Instead of signalling allocation failure with a bool return value
(false), we now use ErrorOr<void> and return ENOMEM as appropriate.
This allows us to use TRY() and MUST() with Vector. :^)
This was required before commit 5f724b6ca1
when we were building LibC before libstdc++ headers were available in
the sysroot. However as noted in that commit, we never actually needed
to be building LibC before libstdc++, so we can go ahead and remove this
ancient hack.
This commit makes it possible to instantiate `Vector<T&>` and use it
to store references to `T` in a vector.
All non-pointer observers are made to return the reference, and the
pointer observers simply yield the underlying pointer.
Note that the 'find_*' methods act on the values and not the pointers
that are stored in the vector.
This commit also makes errors in various vector methods much more
readable by directly using requires-clauses on them.
And finally, it should be noted that Vector cannot hold temporaries :^)
The methods of this class were all over the place, this commit reorders
them to place them in a more logical order:
- Constructors/Destructor
- Observers
- Comparisons and const existence checks
- Mutators: insert
- Mutators: append
- Mutators: prepend
- Mutators: assignment
- Mutators: remove
- OOM-safe mutators: insert
- OOM-safe mutators: append
- OOM-safe mutators: prepend
- OOM-safe size management
- Size management
- Iterators
If a line was larger than 1024 bytes or the file ended without a
newline character, can_read_line would return false.
IODevice::can_read_line() now reads until a newline is found or
EOF is reached.
fixes#5907
This implements the macOS API malloc_good_size() which returns the
true allocation size for a given requested allocation size. This
allows us to make use of all the available memory in a malloc chunk.
For example, for a malloc request of 35 bytes our malloc would
internally use a chunk of size 64, however the remaining 29 bytes
would be unused.
Knowing the true allocation size allows us to request more usable
memory that would otherwise be wasted and make that available for
Vector, HashTable and potentially other callers in the future.
We call placement new for the newly added slots. However, we should
also specify an initializer so primitive data types like u64 are
initialized appropriately.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
Problem:
- Using regular functions rather than function templates results in
the arguments not being deduced. This then requires the same
function to be written multiple times and for `move` to be used
rather than `forward`.
Solution:
- Collapse multiple function overloads to a single function template
with a deduced argument. This allows the argument to be a forwarding
reference and bind to either an l-value or r-value and forward the
value.
Note:
- `append` is not being changed because there are several overloads
for appending single values and concatenating vectors. This
conflation needs to be addressed first.
Problem:
- The implementation of `find` is coupled to the implementation of `Vector`.
- `Vector::find` takes the predicate by value which might be expensive.
Solution:
- Decouple the implementation of `find` from `Vector` by using a
generic `find` algorithm.
- Change the name of `find` with a predicate to `find_if` so that a
binding reference can be used and the predicate can be forwarded to
avoid copies.
- Change all the `find(pred)` call sites to use `find_if`.
clang trunk with -std=c++20 doesn't seem to properly look for an
aggregate initializer here when the type being constructed is a simple
aggregate (e.g. `struct Thing { int a; int b; };`). This template fails
to compile in a usage added 12/16/2020 in `AK/Trie.h`.
Both forms of initialization are supposed to call the
aggregate-initializers but direct-list-initialization delegating to
aggregate initializers is a new addition in c++20 that might not be
implemented yet.
Much like with Vector::append(), you may want to append multiple items in one
go. It's actually more important to do this for prepending, because you don't
want to copy the rest of items further each time.
first_matching returns the first item in the vector that matches
the given condition.
last_matching returns the last item in the vector that matches
the given condition.
Problem:
- C++20 changes the way equality operators are generated. This results
in overload ambiguity as reported by clang.
Solution:
- Remove `AK::Vector::operator!=` because it will be automatically
generated in terms of `AK::Vector::operator==`.
- Change `AK::Vector::operator==` to be a function template so that
overload resolution is not confused about `a == b` vs `b == a`.
- Add tests to ensure the behavior works.
Notes:
- There is more info available at
https://brevzin.github.io/c++/2019/07/28/comparisons-cpp20/ for
deeper discussion about overload resolution, operator rewriting, and
generated functions.
I originally defined the bytes() method for the String class, because it
made it obvious that it's a span of bytes instead of span of characters.
This commit makes this more consistent by defining a bytes() method when
the type of the span is known to be u8.
Additionaly, the cast operator to Bytes is overloaded for ByteBuffer and
such.
The symbol name insertion scheme is different from objdump -d's.
Compare the output on Build/Userland/id:
* disasm:
...
_start (08048305-0804836b):
08048305 push ebp
...
08048366 call 0x0000df56
0804836b o16 nop
0804836d o16 nop
0804836f nop
(deregister_tm_clones (08048370-08048370))
08048370 mov eax, 0x080643e0
...
_ZN2AK8Utf8ViewC1ERKNS_6StringE (0805d9b2-0805d9b7):
_ZN2AK8Utf8ViewC2ERKNS_6StringE (0805d9b2-0805d9b7):
0805d9b2 jmp 0x00014ff2
0805d9b7 nop
* objdump -d:
08048305 <_start>:
8048305: 55 push %ebp
...
8048366: e8 9b dc 00 00 call 8056006 <exit>
804836b: 66 90 xchg %ax,%ax
804836d: 66 90 xchg %ax,%ax
804836f: 90 nop
08048370 <deregister_tm_clones>:
8048370: b8 e0 43 06 08 mov $0x80643e0,%eax
...
0805d9b2 <_ZN2AK8Utf8ViewC1ERKNS_6StringE>:
805d9b2: e9 eb f6 ff ff jmp 805d0a2 <_ZN2AK10StringViewC1ERKNS_6StringE>
805d9b7: 90 nop
Differences:
1. disasm can show multiple symbols that cover the same instructions.
I've only seen this happen for C1/C2 (and D1/D2) ctor/dtor pairs,
but it could conceivably happen with ICF as well.
2. disasm separates instructions that do not belong to a symbol with
a newline, so that nop padding isn't shown as part of a function
when it technically isn't.
3. disasm shows symbols that are skipped (due to having size 0)
in parenthesis, separated from preceding and following instructions.
Use the AK version of std::initializer_list in AK::Vector, but only
when in serenity. When building AK for a non-serenity target, the header
<initializer_list> should be always available.
