Update upstream source from tag 'upstream/1.52.1+dfsg1'

[rustc.git] / vendor / rustc-ap-rustc_target / src / spec / wasm32_unknown_unknown.rs

diff --git a/vendor/rustc-ap-rustc_target/src/spec/wasm32_unknown_unknown.rs b/vendor/rustc-ap-rustc_target/src/spec/wasm32_unknown_unknown.rs
new file mode 100644 (file)
index 0000000..5e89ba2
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+++ b/vendor/rustc-ap-rustc_target/src/spec/wasm32_unknown_unknown.rs
@@ -0,0 +1,49 @@
+//! A "bare wasm" target representing a WebAssembly output that makes zero
+//! assumptions about its environment.
+//!
+//! The `wasm32-unknown-unknown` target is intended to encapsulate use cases
+//! that do not rely on any imported functionality. The binaries generated are
+//! entirely self-contained by default when using the standard library. Although
+//! the standard library is available, most of it returns an error immediately
+//! (e.g. trying to create a TCP stream or something like that).
+//!
+//! This target is more or less managed by the Rust and WebAssembly Working
+//! Group nowadays at <https://github.com/rustwasm>.
+
+use super::wasm32_base;
+use super::{LinkerFlavor, LldFlavor, Target};
+
+pub fn target() -> Target {
+    let mut options = wasm32_base::options();
+    options.os = "unknown".to_string();
+    options.linker_flavor = LinkerFlavor::Lld(LldFlavor::Wasm);
+    let clang_args = options.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap();
+
+    // Make sure clang uses LLD as its linker and is configured appropriately
+    // otherwise
+    clang_args.push("--target=wasm32-unknown-unknown".to_string());
+
+    // For now this target just never has an entry symbol no matter the output
+    // type, so unconditionally pass this.
+    clang_args.push("-Wl,--no-entry".to_string());
+
+    // Rust really needs a way for users to specify exports and imports in
+    // the source code. --export-dynamic isn't the right tool for this job,
+    // however it does have the side effect of automatically exporting a lot
+    // of symbols, which approximates what people want when compiling for
+    // wasm32-unknown-unknown expect, so use it for now.
+    clang_args.push("-Wl,--export-dynamic".to_string());
+
+    // Add the flags to wasm-ld's args too.
+    let lld_args = options.pre_link_args.get_mut(&LinkerFlavor::Lld(LldFlavor::Wasm)).unwrap();
+    lld_args.push("--no-entry".to_string());
+    lld_args.push("--export-dynamic".to_string());
+
+    Target {
+        llvm_target: "wasm32-unknown-unknown".to_string(),
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-i64:64-n32:64-S128".to_string(),
+        arch: "wasm32".to_string(),
+        options,
+    }
+}