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
`wasi_snapshot_preview1` introduced a couple of ABI changes. This
commit fast-forwards the types and consts defined in `std.os.bits.wasi`
to match those changes.
* `zig test` gainst `--test-evented-io` parameter and gains the ability
to seamlessly run async tests.
* `std.ChildProcess` opens its child process pipe with O_NONBLOCK when
using evented I/O
* `std.io.getStdErr()` gives a File that is blocking even in evented
I/O mode.
* Delete `std.event.fs`. The functionality is now merged into `std.fs`
and async file system access (using a dedicated thread) is
automatically handled.
* `std.fs.File` can be configured to specify whether its handle is
expected to block, and whether that is OK to block even when in
async I/O mode. This makes async I/O work correctly for e.g. the
file system as well as network.
* `std.fs.File` has some deprecated functions removed.
* Missing readv,writev,pread,pwrite,preadv,pwritev functions are added
to `std.os` and `std.fs.File`. They are all integrated with async
I/O.
* `std.fs.Watch` is still bit rotted and needs to be audited in light
of the new async/await syntax.
* `std.io.OutStream` integrates with async I/O
* linked list nodes in the std lib have default `null` values for
`prev` and `next`.
* Windows async I/O integration is enabled for reading/writing file
handles.
* Added `std.os.mode_t`. Integer sizes need to be audited.
* Fixed#4403 which was causing compiler to crash.
This is working towards:
./zig test ../test/stage1/behavior.zig --test-evented-io
Which does not successfully build yet. I'd like to enable behavioral
tests and std lib tests with --test-evented-io in the test matrix in the
future, to prevent regressions.
