Use error.AccessDenied for permissions (rights) failures on Wasi
(`EACCES`) and error.PermissionDenied (`EPERM`) for systemic failures.
And pass-through underlying Wasi errors (PermissionDenied or AccessDenied)
without mapping.
Windows defines an `ACCESS_DENIED` error code. There is no
PERMISSION_DENIED (or its equivalent) which seems to only exist on POSIX
systems. Fix a couple Windows calls code to return `error.AccessDenied`
for `ACCESS_DENIED` and to stop mapping AccessDenied into
PermissionDenied.
Emscripten currently implements `emscripten_return_address()` by calling
out into JavaScript and parsing a stack trace, which introduces
significant overhead that we would prefer to avoid in release builds.
This is especially problematic for allocators because the generic parts
of `std.mem.Allocator` make frequent use of `@returnAddress`, even
though very few allocator implementations even observe the return
address, which makes allocators nigh unusable for performance-critical
applications like games if the compiler is unable to devirtualize the
allocator calls.
Both sliceTo and indexOfScalarPos use SIMD when available to speed up the search. On my x86_64 machine, this leads to getenvW being around 2-3x faster overall.
Additionally, any future improvements to sliceTo/indexOfScalarPos will benefit getenvW.
Too many bugs have been found with `truncate` at this point, so it was
rewritten from scratch.
Based on the doc comment, the utility of `convertToTwosComplement` over
`r.truncate(a, .unsigned, bit_count)` is unclear and it has a subtle
behavior difference that is almost certainly a bug, so it was deleted.
This code previously added 4 NUL code units, but that was likely due to a misinterpretation of this part of the CreateProcess documentation:
> A Unicode environment block is terminated by four zero bytes: two for the last string, two more to terminate the block.
(four zero *bytes* means *two* zero code units)
Additionally, the second zero code unit is only actually needed when the environment is empty due to a quirk of the CreateProcess implementation. In the case of a non-empty environment, there always ends up being two trailing NUL code units since one will come after the last environment variable in the block.
The code did one useless thing and two wrong things:
- ref counting was basically a noop
- last_dir_fd was chosen from the wrong index and also under the wrong
condition
This caused regular crashes on macOS which are now gone.
* use `tmp.dir.realpathAlloc()` to get full path into tmpDir instances
* use `testing.allocator` where that simplifies things (vs. manual ArenaAllocator for 1 or 2 allocs)
* Trust `TmpDir.cleanup()` to clean up contained files and sub-trees
* Remove some unnecessary absolute paths (enabling WASI to run the tests)
* Drop some no-longer necessary `[_][]const u8` casts
* Add scopes to reduce `var` usage in favor of `const`
This commits adds the following distinct integer types to std.zig.Ast:
- OptionalTokenIndex
- TokenOffset
- OptionalTokenOffset
- Node.OptionalIndex
- Node.Offset
- Node.OptionalOffset
The `Node.Index` type has also been converted to a distinct type while
`TokenIndex` remains unchanged.
`Ast.Node.Data` has also been changed to a (untagged) union to provide
safety checks.
This function checks for various possibilities that are never produced
by the parser.
Given that lastToken is unsafe to call on an Ast with errors, I also
removed code paths that would be reachable on an Ast with errors.
