std.ast uses a singly linked list for lists of things. This is a
breaking change to the self-hosted parser API.
std.ast.Tree has been separated into a private "Parser" type which
represents in-progress parsing, and std.ast.Tree which has only
"output" data. This means cleaner, but breaking, API for parse results.
Specifically, `tokens` and `errors` are no longer SegmentedList but a
slice.
The way to iterate over AST nodes has necessarily changed since lists of
nodes are now singly linked lists rather than SegmentedList.
From these changes, I observe the following on the
self-hosted-parser benchmark from ziglang/gotta-go-fast:
throughput: 45.6 MiB/s => 55.6 MiB/s
maxrss: 359 KB => 342 KB
This commit breaks the build; more updates are necessary to fix API
usage of the self-hosted parser.
This rather large commit adds/fixes missing WASI functionality
in `libstd` needed to pass the `libstd` tests. As such, now by
default tests targeting `wasm32-wasi` target are enabled in
`test/tests.zig` module. However, they can be disabled by passing
the `-Dskip-wasi=true` flag when invoking the `zig build test`
command. When the flag is set to `false`, i.e., when WASI tests are
included, `wasmtime` with `--dir=.` is used as the default testing
command.
Since the majority of `libstd` tests were relying on `fs.cwd()`
call to get current working directory handle wrapped in `Dir`
struct, in order to make the tests WASI-friendly, `fs.cwd()`
call was replaced with `testing.getTestDir()` function which
resolved to either `fs.cwd()` for non-WASI targets, or tries to
fetch the preopen list from the WASI runtime and extract a
preopen for '.' path.
The summary of changes introduced by this commit:
* implement `Dir.makeDir` and `Dir.openDir` targeting WASI
* implement `Dir.deleteFile` and `Dir.deleteDir` targeting WASI
* fix `os.close` and map errors in `unlinkat`
* move WASI-specific `mkdirat` and `unlinkat` from `std.fs.wasi`
to `std.os` module
* implement `lseek_{SET, CUR, END}` targeting WASI
* implement `futimens` targeting WASI
* implement `ftruncate` targeting WASI
* implement `readv`, `writev`, `pread{v}`, `pwrite{v}` targeting WASI
* make sure ANSI escape codes are _not_ used in stderr or stdout
in WASI, as WASI always sanitizes stderr, and sanitizes stdout if
fd is a TTY
* fix specifying WASI rights when opening/creating files/dirs
* tweak `AtomicFile` to be WASI-compatible
* implement `os.renameatWasi` for WASI-compliant `os.renameat` function
* implement sleep() targeting WASI
* fix `process.getEnvMap` targeting WASI
