This one changes the size of an allocation, allowing it to be relocated.
However, the implementation will still return `null` if it would be
equivalent to
new = alloc
memcpy(new, old)
free(old)
Mainly this prepares for taking advantage of `mremap` which I thought
would be a bigger deal but apparently is only available on Linux. Still,
we should use it on Linux.
This commit reworks how anonymous struct literals and tuples work.
Previously, an untyped anonymous struct literal
(e.g. `const x = .{ .a = 123 }`) was given an "anonymous struct type",
which is a special kind of struct which coerces using structural
equivalence. This mechanism was a holdover from before we used
RLS / result types as the primary mechanism of type inference. This
commit changes the language so that the type assigned here is a "normal"
struct type. It uses a form of equivalence based on the AST node and the
type's structure, much like a reified (`@Type`) type.
Additionally, tuples have been simplified. The distinction between
"simple" and "complex" tuple types is eliminated. All tuples, even those
explicitly declared using `struct { ... }` syntax, use structural
equivalence, and do not undergo staged type resolution. Tuples are very
restricted: they cannot have non-`auto` layouts, cannot have aligned
fields, and cannot have default values with the exception of `comptime`
fields. Tuples currently do not have optimized layout, but this can be
changed in the future.
This change simplifies the language, and fixes some problematic
coercions through pointers which led to unintuitive behavior.
Resolves: #16865
Follow up to #19079, which made test names fully qualified.
This fixes tests that now-redundant information in their test names. For example here's a fully qualified test name before the changes in this commit:
"priority_queue.test.std.PriorityQueue: shrinkAndFree"
and the same test's name after the changes in this commit:
"priority_queue.test.shrinkAndFree"
The code asserted that the range to be replaced is within bounds of
`self.items`.
This is now reflected in the doc comment.
The old, wrong doc comment was copied from the `insert*` fns.
With this assertion holding true, `start + len` is always within the
address space and `start + new_items.len` is, at this point, always
strictly within bounds of `self.items`.
This is useful when you want to have an array list backed by a fixed
slice of memory and no Allocator will be used.
It's an alternative to BoundedArray as you will see in the following
commit.
This reverts commit 0c99ba1eab63865592bb084feb271cd4e4b0357e, reversing
changes made to 5f92b070bf284f1493b1b5d433dd3adde2f46727.
This caused a CI failure when it landed in master branch due to a
128-bit `@byteSwap` in std.mem.
(Unmanaged)ArrayList.insert has the same inefficiency as the old insertSlice. With the new addManyAt, the solution is trivial.
Also improves the test "growing memory preserves contents". In the previous implementation, if any changes were made to the ArrayList memory growth policy (function growMemory), the list could end up with enough capacity to not trigger a memory growth, defeating the purpose of the test. The new implementation more robustly triggers a memory growth.
* Move `computeBetterCapacity` to the bottom so that `pub` stuff shows
up first.
* Rename `computeBetterCapacity` to `growCapacity`. Every function
implicitly computes something; that word is always redundant in a
function name. "better" is vague. Better in what way? Instead we
describe what is actually happening. "grow".
* Improve doc comments to be very explicit about when element pointers
are invalidated or not.
* Rename `addManyAtIndex` to `addManyAt`. The parameter is named
`index`; that is enough.
* Extract some duplicated code into `addManyAtAssumeCapacity` and make
it `pub`.
* Since I audited every line of code for correctness, I changed the
style to my personal preference.
* Avoid a redundant `@memset` to `undefined` - memory allocation does
that already.
* Fixed comment giving the wrong reason for not calling
`ensureTotalCapacity`.
Includes a more robust implementation of replaceRange, which updates the
ArrayListUnmanaged if state changes in the managed part of the code
before returning an error.
Co-authored-by: Andrew Kelley <andrew@ziglang.org>
Now that allocator.resize() is allowed to fail, programs may wish to
test code paths that handle resize() failure. The simplest way to do
this now is to replace the vtable of the testing allocator with one
that uses Allocator.noResize for the 'resize' function pointer.
An alternative way to support this testing capability is to augment the
FailingAllocator (which is already useful for testing allocation failure
scenarios) to intentionally fail on calls to resize(). To do this, add a
'resize_fail_index' parameter to the FailingAllocator that causes
resize() to fail after the given number of calls.
The 'at least' behavior of the Allocator interface was removed in #13666, so anything that used reallocAtLeast or the .at_least Exact behavior could still have doc comments that reference no-longer-true behavior.
Funnily enough, ArrayList is the only place that used this functionality (outside of allocator test cases), so its doc comments are the only things that need to be fixed. This was checked by resetting to deda6b514691c3a7ffc7931469886d0e7be2f67e and searching for all instances of `reallocAtLeast` and `.at_least` (one of which would need to be used to get the `.at_least` behavior)
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
The previous commit introduced an optimization to the LLVM backend that
makes `@memset` lower more optimally when the element is comptime-known
and has a repeating byte pattern.
By making these functions inline, if the element parameter is
comptime-known at the callsite, it will be comptime-known in the
`@memset` call, causing more use of the LLVM `memset` intrinsic rather
than an inline for loop when using the LLVM backend.
This affects, for example, std.crypto.argon2, which calls
appendNTimesAssumeCapacity with a `[128]u64` as the element. This is now
lowered with a single `memset` call.
Now they use slices or array pointers with any element type instead of
requiring byte pointers.
This is a breaking enhancement to the language.
The safety check for overlapping pointers will be implemented in a
future commit.
closes#14040
* docs(std.math): elaborate on difference between absCast and absInt
* docs(std.rand.Random.weightedIndex): elaborate on likelihood
I think this makes it easier to understand.
* langref: add small reminder
* docs(std.fs.path.extension): brevity
* docs(std.bit_set.StaticBitSet): mention the specific types
* std.debug.TTY: explain what purpose this struct serves
This should also make it clearer that this struct is not supposed to provide unrelated terminal manipulation functionality such as setting the cursor position or something because terminals are complicated and we should keep this struct simple and focused on debugging.
* langref(package listing): brevity
* langref: explain what exactly `threadlocal` causes to happen
* std.array_list: link between swapRemove and orderedRemove
Maybe this can serve as a TLDR and make it easier to decide.
* PrefetchOptions.locality: clarify docs that this is a range
This confused me previously and I thought I can only use either 0 or 3.
* fix typos and more
* std.builtin.CallingConvention: document some CCs
* langref: explain possibly cryptic names
I think it helps knowing what exactly these acronyms (@clz and @ctz) and
abbreviations (@popCount) mean.
* variadic function error: add missing preposition
* std.fmt.format docs: nicely hyphenate
* help menu: say what to optimize for
I think this is slightly more specific than just calling it
"optimizations". These are speed optimizations. I used the word
"performance" here.
