1 //! A "bare wasm" target representing a WebAssembly output that makes zero
2 //! assumptions about its environment.
4 //! The `wasm32-unknown-unknown` target is intended to encapsulate use cases
5 //! that do not rely on any imported functionality. The binaries generated are
6 //! entirely self-contained by default when using the standard library. Although
7 //! the standard library is available, most of it returns an error immediately
8 //! (e.g. trying to create a TCP stream or something like that).
10 //! This target is more or less managed by the Rust and WebAssembly Working
11 //! Group nowadays at https://github.com/rustwasm.
13 use super::wasm32_base;
14 use super::{LinkerFlavor, LldFlavor, Target};
16 pub fn target() -> Result<Target, String> {
17 let mut options = wasm32_base::options();
18 let clang_args = options.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap();
20 // Make sure clang uses LLD as its linker and is configured appropriately
22 clang_args.push("--target=wasm32-unknown-unknown".to_string());
24 // Disable attempting to link crt1.o since it typically isn't present and
25 // isn't needed currently.
26 clang_args.push("-nostdlib".to_string());
28 // For now this target just never has an entry symbol no matter the output
29 // type, so unconditionally pass this.
30 clang_args.push("-Wl,--no-entry".to_string());
33 .get_mut(&LinkerFlavor::Lld(LldFlavor::Wasm))
35 .push("--no-entry".to_string());
38 llvm_target: "wasm32-unknown-unknown".to_string(),
39 target_endian: "little".to_string(),
40 target_pointer_width: "32".to_string(),
41 target_c_int_width: "32".to_string(),
42 target_os: "unknown".to_string(),
43 target_env: String::new(),
44 target_vendor: "unknown".to_string(),
45 data_layout: "e-m:e-p:32:32-i64:64-n32:64-S128".to_string(),
46 arch: "wasm32".to_string(),
47 linker_flavor: LinkerFlavor::Lld(LldFlavor::Wasm),