Merge branch 'feature/wasi-return-exit-code' of github.com:wasmerio/wasmer into feature/wasi-return-exit-code

CHANGELOG.md

@@ -5,6 +5,7 @@ All PRs to the Wasmer repository must add to this file.
 Blocks of changes will separated by version increments.
 
 ## **[Unreleased]**
+- [#382](https://github.com/wasmerio/wasmer/pull/382) Improve error message on `--backend` flag to only suggest currently enabled backends
 - [#381](https://github.com/wasmerio/wasmer/pull/381) Allow retrieving propagated user errors.
 - [#379](https://github.com/wasmerio/wasmer/pull/379) Fix small return types from imported functions.
 - [#371](https://github.com/wasmerio/wasmer/pull/371) Add more Debug impl for WASI types

src/bin/wasmer.rs

@@ -108,7 +108,13 @@ enum Backend {
 
 impl Backend {
     pub fn variants() -> &'static [&'static str] {
-        &["singlepass", "cranelift", "llvm"]
+        &[
+            "cranelift",
+            #[cfg(feature = "backend:singlepass")]
+            "singlepass",
+            #[cfg(feature = "backend:llvm")]
+            "llvm",
+        ]
     }
 }