Use include_bytes! in shader! for automatic recompilation (#1523)

vulkano-shaders/src/codegen.rs

@@ -191,6 +191,7 @@ pub(super) fn reflect(
     name: &str,
     spirv: &[u32],
     types_meta: TypesMeta,
+    full_path: Option<&str>,
     dump: bool,
 ) -> Result<TokenStream, Error> {
     let struct_name = Ident::new(&name, Span::call_site());
@@ -255,6 +256,12 @@ pub(super) fn reflect(
         }
     }
 
+    let include_bytes = full_path.map(|s| quote! {
+        // using include_bytes here ensures that changing the shader will force recompilation.
+        // The bytes themselves can be optimized out by the compiler as they are unused.
+        let _bytes = ::std::include_bytes!( #s );
+    }).unwrap_or(TokenStream::new());
+
     let structs = structs::write_structs(&doc, &types_meta);
     let specialization_constants = spec_consts::write_specialization_constants(&doc, &types_meta);
     let uses = &types_meta.uses;
@@ -308,6 +315,8 @@ pub(super) fn reflect(
             pub fn load(device: ::std::sync::Arc<::vulkano::device::Device>)
                         -> Result<#struct_name, ::vulkano::OomError>
             {
+                #include_bytes
+
                 #( #cap_checks )*
                 static WORDS: &[u32] = &[ #( #spirv ),* ];
 

vulkano-shaders/src/lib.rs

@@ -574,23 +574,27 @@ pub fn shader(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
             "Shader",
             unsafe { from_raw_parts(bytes.as_slice().as_ptr() as *const u32, bytes.len() / 4) },
             input.types_meta,
+            None,
             input.dump,
         )
         .unwrap()
         .into()
     } else {
-        let (path, source_code) = match input.source_kind {
-            SourceKind::Src(source) => (None, source),
-            SourceKind::Path(path) => (Some(path.clone()), {
+        let (path, full_path, source_code) = match input.source_kind {
+            SourceKind::Src(source) => (None, None, source),
+            SourceKind::Path(path) => {
                 let full_path = root_path.join(&path);
 
                 if full_path.is_file() {
+                    (Some(path.clone()),
+                     Some(full_path.to_str()
+                          .expect("Path {:?} could not be converted to UTF-8").to_owned()),
                     read_file_to_string(&full_path)
-                        .expect(&format!("Error reading source from {:?}", path))
+                        .expect(&format!("Error reading source from {:?}", path)))
                 } else {
                     panic!("File {:?} was not found ; note that the path must be relative to your Cargo.toml", path);
                 }
-            }),
+            }
             SourceKind::Bytes(_) => unreachable!(),
         };
 
@@ -617,7 +621,7 @@ pub fn shader(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
             Err(e) => panic!("{}", e.replace("(s): ", "(s):\n")),
         };
 
-        codegen::reflect("Shader", content.as_binary(), input.types_meta, input.dump)
+        codegen::reflect("Shader", content.as_binary(), input.types_meta, full_path.as_deref(), input.dump)
             .unwrap()
             .into()
     }