std.heap.c_allocator was already doing this, however,
std.heap.raw_c_allocator, which asserts no allocations more than 16
bytes aligned, was not.
The zig compiler uses std.heap.raw_c_allocator, so it is affected by
this.
This eliminates some simple usages of `usingnamespace` in the standard
library. This construct may in future be removed from the language, and
is generally an inappropriate way to formulate code. It is also
problematic for incremental compilation, which may not initially support
projects using it.
I wasn't entirely sure what the appropriate namespacing for the types in
`std.os.uefi.tables` would be, so I ofted to preserve the current
namespacing, meaning this is not a breaking change. It's possible some
of the moved types should instead be namespaced under `BootServices`
etc, but this can be a future enhancement.
These changes enable me to use `GeneralPurposeAllocator` with my "Bring
Your Own OS" package. The previous checks for a freestanding target have
been expanded to `@hasDecl` checks.
- `root.os.heap.page_allocator` is used if it exists.
- `debug.isValidMemory` only calls `os.msync` if it's supported.
Implements issue #6451.
This was needed to support allocation on Plan 9 and now other operating
systems like DOS can also use it.
It is a modified version of the WasmAllocator since wasm also uses a
sbrk-esque allocation system.
This commit also adds the necessary system bits for sbrk to work on plan 9.
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
Anecdote 1: The generic version is way more popular than the non-generic
one in Zig codebase:
git grep -w alignForward | wc -l
56
git grep -w alignForwardGeneric | wc -l
149
git grep -w alignBackward | wc -l
6
git grep -w alignBackwardGeneric | wc -l
15
Anecdote 2: In my project (turbonss) that does much arithmetic and
alignment I exclusively use the Generic functions.
Anecdote 3: we used only the Generic versions in the Macho Man's linker
workshop.
The majority of these are in comments, some in doc comments which might
affect the generated documentation, and a few in parameter names -
nothing that should be breaking, however.
The previous version had a fatal flaw: it did ensureCapacity(1) on the
freelist when allocating, but I neglected to consider that you could
free() twice in a row. Silly!
This strategy allocates an intrusive freelist node with every
allocation, big or small. It also does not have the problems with resize
because in this case we can push the upper areas of freed stuff into the
corresponding freelist.
When a number of bytes to be allocated is so great that alignForward()
is not possible, return `error.OutOfMemory`.
Companion commit to 3f3003097cbf5a6ad9e0dfc29b2cafbe2e35dded.
Instead of making the memory alignment functions more complicated, I
added more API documentation for their existing semantics.
closes#12118closes#12135
The main purpose of this branch is to explore avoiding the
`usingnamespace` feature of the zig language, specifically with regards
to `std.os` and related functionality.
If this experiment is successful, it will provide a data point on
whether or not it would be practical to entirely remove `usingnamespace`
from the language.
In this commit, `usingnamespace` has been completely eliminated from
the Linux x86_64 compilation path, aside from io_uring.
The behavior tests pass, however that's as far as this branch goes. It is
very breaking, and a lot more work is needed before it could be
considered mergeable. I wanted to put a pull requset up early so that
zig programmers have time to provide feedback.
This is progress towards closing #6600 since it clarifies where the
actual "owner" of each declaration is, and reduces the number of
different ways to import the same declarations.
One of the main organizational strategies used here is to do namespacing
with real namespaces (e.g. structs) rather than by having declarations
share a common prefix (the C strategy). It's no coincidence that
`usingnamespace` has similar semantics to `#include` and becomes much
less necessary when using proper namespaces.
We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.
Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
