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
Now there are 3 types:
* std.math.big.int.Const
- the memory is immutable, only stores limbs and is_positive
- all methods operating on constant data go here
* std.math.big.int.Mutable
- the memory is mutable, stores capacity in addition to limbs and
is_positive
- methods here have some Mutable parameters and some Const
parameters. These methods expect callers to pre-calculate the
amount of resources required, and asserts that the resources are
available.
* std.math.big.int.Managed
- the memory is mutable and additionally stores an allocator.
- methods here perform the resource calculations for the programmer.
- this is the high level abstraction from before
Each of these 3 types can be converted to the other ones.
You can see the use case for this in the self-hosted compiler, where we
only store limbs, and construct the big ints as needed.
This gets rid of the hack where the allocator was optional and the
notion of "fixed" versions of the struct. Such things are now modeled
with the `big.int.Const` type.
Zig now supports a more fine-grained sense of what is native and what is
not. Some examples:
This is now allowed:
-target native
Different OS but native CPU, default Windows C ABI:
-target native-windows
This could be useful for example when running in Wine.
Different CPU but native OS, native C ABI.
-target x86_64-native -mcpu=skylake
Different C ABI but otherwise native target:
-target native-native-musl
-target native-native-gnu
Lots of breaking changes to related std lib APIs.
Calls to getOs() will need to be changed to getOsTag().
Calls to getArch() will need to be changed to getCpuArch().
Usage of Target.Cross and Target.Native need to be updated to use
CrossTarget API.
`std.build.Builder.standardTargetOptions` is changed to accept its
parameters as a struct with default values. It now has the ability to
specify a whitelist of targets allowed, as well as the default target.
Rather than two different ways of collecting the target, it's now always
a string that is validated, and prints helpful diagnostics for invalid
targets. This feature should now be actually useful, and contributions
welcome to further improve the user experience.
`std.build.LibExeObjStep.setTheTarget` is removed.
`std.build.LibExeObjStep.setTarget` is updated to take a CrossTarget
parameter.
`std.build.LibExeObjStep.setTargetGLibC` is removed. glibc versions are
handled in the CrossTarget API and can be specified with the `-target`
triple.
`std.builtin.Version` gains a `format` method.
This change was mostly made with `zig fmt` and this also modified some whitespace. Note that in some files, `zig fmt` produced incorrect code, so the change was made manually.
Show differing pointer values when comparing pointers instead of the
content they point to.
It's confusing for a test to say "expected S{.x = 1}, found S{.x = 1}"
as illustrated below when it was the pointers that differed.
There seems to be different rules for when a pointer is dereferenced by
the printing routine depending on its type. I don't fully grok this but
it's also illustrated below.
const std = @import("std");
const S = struct { x: u32 };
// before: ...expected S{ .x = 1 }, found S{ .x = 1 }
// after: ...expected S@7ffcd20b7798, found S@7ffcd20b7790
test "compare_ptr_to_struct" {
var a = S{.x = 1};
var b = S{.x = 1};
std.testing.expectEqual(&a, &b);
}
// before: ...expected u32@7fff316ba31c, found u32@7fff316ba318
// after: ...expected u32@7ffecec622dc, found u32@7ffecec622d8
test "compare_ptr_to_scalar" {
var a: u32 = 1;
var b: u32 = 1;
std.testing.expectEqual(&a, &b);
}