rustc_target/spec/targets/wasm32_wasip1.rs
1//! The `wasm32-wasip1` enables compiling to WebAssembly using the first
2//! version of the WASI standard, called "preview1". This version of the
3//! standard was never formally specified and WASI has since evolved to a
4//! "preview2". This target in rustc uses the previous version of the proposal.
5//!
6//! This target uses the syscalls defined at
7//! <https://github.com/WebAssembly/WASI/tree/main/legacy/preview1>.
8//!
9//! Note that this target was historically called `wasm32-wasi` originally and
10//! was since renamed to `wasm32-wasip1` after the preview2 target was
11//! introduced.
12
13use crate::spec::{
14 Cc, LinkSelfContainedDefault, LinkerFlavor, Target, TargetMetadata, base, crt_objects,
15};
16
17pub(crate) fn target() -> Target {
18 let mut options = base::wasm::options();
19
20 options.os = "wasi".into();
21 options.env = "p1".into();
22 options.add_pre_link_args(LinkerFlavor::WasmLld(Cc::Yes), &["--target=wasm32-wasip1"]);
23
24 options.pre_link_objects_self_contained = crt_objects::pre_wasi_self_contained();
25 options.post_link_objects_self_contained = crt_objects::post_wasi_self_contained();
26
27 // FIXME: Figure out cases in which WASM needs to link with a native toolchain.
28 options.link_self_contained = LinkSelfContainedDefault::True;
29
30 // Right now this is a bit of a workaround but we're currently saying that
31 // the target by default has a static crt which we're taking as a signal
32 // for "use the bundled crt". If that's turned off then the system's crt
33 // will be used, but this means that default usage of this target doesn't
34 // need an external compiler but it's still interoperable with an external
35 // compiler if configured correctly.
36 options.crt_static_default = true;
37 options.crt_static_respected = true;
38
39 // Allow `+crt-static` to create a "cdylib" output which is just a wasm file
40 // without a main function.
41 options.crt_static_allows_dylibs = true;
42
43 // WASI's `sys::args::init` function ignores its arguments; instead,
44 // `args::args()` makes the WASI API calls itself.
45 options.main_needs_argc_argv = false;
46
47 // And, WASI mangles the name of "main" to distinguish between different
48 // signatures.
49 options.entry_name = "__main_void".into();
50
51 Target {
52 llvm_target: "wasm32-wasip1".into(),
53 metadata: TargetMetadata {
54 description: Some("WebAssembly with WASI".into()),
55 tier: Some(2),
56 host_tools: Some(false),
57 std: Some(true),
58 },
59 pointer_width: 32,
60 data_layout: "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20".into(),
61 arch: "wasm32".into(),
62 options,
63 }
64}