diff --git a/Cargo.toml b/Cargo.toml
index 3c60739c39..803c506f9b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -25,10 +25,11 @@ default = []
 glsl-in = ["pomelo"]
 glsl-validate = []
 glsl-out = []
+msl-out = []
 serialize = ["serde"]
 deserialize = ["serde"]
-spirv-in = ["petgraph", "spirv"]
-spirv-out = ["spirv"]
+spv-in = ["petgraph", "spirv"]
+spv-out = ["spirv"]
 wgsl-in = []
 
 [dev-dependencies]
diff --git a/examples/convert.rs b/examples/convert.rs
index 76f5a156e5..3b219540c5 100644
--- a/examples/convert.rs
+++ b/examples/convert.rs
@@ -35,7 +35,7 @@ fn main() {
         .to_str()
         .unwrap()
     {
-        #[cfg(feature = "spirv-in")]
+        #[cfg(feature = "spv-in")]
         "spv" => {
             let input = fs::read(&args[1]).unwrap();
             naga::front::spv::parse_u8_slice(&input).unwrap()
@@ -80,7 +80,13 @@ fn main() {
             let mut input = fs::File::open(&args[1]).unwrap();
             ron::de::from_reader(&mut input).unwrap()
         }
-        other => panic!("Unknown input extension: {}", other),
+        other => {
+            if true {
+                // prevent "unreachable_code" warnings
+                panic!("Unknown input extension: {}", other);
+            }
+            naga::Module::generate_empty()
+        }
     };
 
     if args.len() <= 2 {
@@ -100,6 +106,7 @@ fn main() {
         .to_str()
         .unwrap()
     {
+        #[cfg(feature = "msl-out")]
         "metal" => {
             use naga::back::msl;
             let mut binding_map = msl::BindingMap::default();
@@ -123,7 +130,7 @@ fn main() {
             let msl = msl::write_string(&module, options).unwrap();
             fs::write(&args[2], msl).unwrap();
         }
-        #[cfg(feature = "spirv-out")]
+        #[cfg(feature = "spv-out")]
         "spv" => {
             use naga::back::spv;
 
@@ -189,6 +196,7 @@ fn main() {
             fs::write(&args[2], output).unwrap();
         }
         other => {
+            let _ = params;
             panic!("Unknown output extension: {}", other);
         }
     }
diff --git a/src/back/mod.rs b/src/back/mod.rs
index fc601cd9fc..bc96dd3496 100644
--- a/src/back/mod.rs
+++ b/src/back/mod.rs
@@ -2,6 +2,7 @@
 
 #[cfg(feature = "glsl-out")]
 pub mod glsl;
+#[cfg(feature = "msl-out")]
 pub mod msl;
-#[cfg(feature = "spirv-out")]
+#[cfg(feature = "spv-out")]
 pub mod spv;
diff --git a/src/front/mod.rs b/src/front/mod.rs
index ec7738963d..3e74645776 100644
--- a/src/front/mod.rs
+++ b/src/front/mod.rs
@@ -2,7 +2,7 @@
 
 #[cfg(feature = "glsl-in")]
 pub mod glsl;
-#[cfg(feature = "spirv-in")]
+#[cfg(feature = "spv-in")]
 pub mod spv;
 #[cfg(feature = "wgsl-in")]
 pub mod wgsl;
@@ -11,9 +11,8 @@ use crate::arena::Arena;
 
 pub const GENERATOR: u32 = 0;
 
-#[allow(dead_code)]
 impl crate::Module {
-    fn from_header(header: crate::Header) -> Self {
+    pub fn from_header(header: crate::Header) -> Self {
         crate::Module {
             header,
             types: Arena::new(),
@@ -24,7 +23,7 @@ impl crate::Module {
         }
     }
 
-    fn generate_empty() -> Self {
+    pub fn generate_empty() -> Self {
         Self::from_header(crate::Header {
             version: (1, 0, 0),
             generator: GENERATOR,
diff --git a/tests/convert.rs b/tests/convert.rs
index a95d4affd6..d6a1243c39 100644
--- a/tests/convert.rs
+++ b/tests/convert.rs
@@ -1,3 +1,4 @@
+#[allow(dead_code)]
 fn load_test_data(name: &str) -> String {
     let path = format!("{}/test-data/{}", env!("CARGO_MANIFEST_DIR"), name);
     std::fs::read_to_string(path).unwrap()
@@ -9,7 +10,7 @@ fn load_wgsl(name: &str) -> naga::Module {
     naga::front::wgsl::parse_str(&input).unwrap()
 }
 
-#[cfg(feature = "spirv-in")]
+#[cfg(feature = "spv-in")]
 fn load_spv(name: &str) -> naga::Module {
     let path = format!("{}/test-data/spv/{}", env!("CARGO_MANIFEST_DIR"), name);
     let input = std::fs::read(path).unwrap();
@@ -27,6 +28,7 @@ fn load_glsl(name: &str, entry: &str, stage: naga::ShaderStage) -> naga::Module
 fn convert_quad() {
     let module = load_wgsl("quad.wgsl");
     naga::proc::Validator::new().validate(&module).unwrap();
+    #[cfg(feature = "msl-out")]
     {
         use naga::back::msl;
         let mut binding_map = msl::BindingMap::default();
@@ -60,6 +62,7 @@ fn convert_quad() {
 fn convert_boids() {
     let module = load_wgsl("boids.wgsl");
     naga::proc::Validator::new().validate(&module).unwrap();
+    #[cfg(feature = "msl-out")]
     {
         use naga::back::msl;
         let mut binding_map = msl::BindingMap::default();
@@ -97,7 +100,7 @@ fn convert_boids() {
     }
 }
 
-#[cfg(feature = "spirv-in")]
+#[cfg(feature = "spv-in")]
 #[test]
 fn convert_cube() {
     let mut validator = naga::proc::Validator::new();
@@ -105,7 +108,7 @@ fn convert_cube() {
     validator.validate(&vs).unwrap();
     let fs = load_spv("cube.frag.spv");
     validator.validate(&fs).unwrap();
-
+    #[cfg(feature = "msl-out")]
     {
         use naga::back::msl;
         let mut binding_map = msl::BindingMap::default();