various fixes

crates/wit/src/parsed_type.rs

@@ -177,14 +177,14 @@ fn parse_vec_bracket(args: &syn::PathArguments) -> syn::Result<&syn::Type> {
         syn::PathArguments::AngleBracketed(args) => Ok(args),
         _ => Err(Error::new(
             args.span(),
-            "It has to be a bracketed value after Vec",
+            "expected value in angle brackets (<>)",
         )),
     }?;
 
     let arg = generic_arg.args.first().ok_or_else(|| {
         Error::new(
             generic_arg.span(),
-            "Unsuitable type in Vec brackets, lifetimes, bindings, constraints and consts are unsupported",
+            "Invalid type in Vec brackets. (NOTE: lifetimes, bindings, constraints and consts are not supported)",
         )
     })?;
 
@@ -193,7 +193,7 @@ fn parse_vec_bracket(args: &syn::PathArguments) -> syn::Result<&syn::Type> {
         syn::GenericArgument::Type(ty) => Ok(ty),
         _ => Err(Error::new(
             arg.span(),
-            "Unsuitable type in Vec brackets, lifetimes, bindings, constraints and consts are unsupported",
+            "Invalid type in Vec brackets. (NOTE: lifetimes, bindings, constraints and consts are not supported)",
         )),
     }
 }

crates/wit/src/parsed_type/fn_epilog.rs

@@ -44,7 +44,13 @@ pub(crate) trait FnEpilogGlueCodeGenerator {
     fn generate_fn_epilog(&self) -> FnEpilogDescriptor;
 }
 
-impl FnEpilogGlueCodeGenerator for (&Vec<(String, ParsedType)>, &Vec<syn::Ident>, &Option<ParsedType>) {
+impl FnEpilogGlueCodeGenerator
+    for (
+        &Vec<(String, ParsedType)>,
+        &Vec<syn::Ident>,
+        &Option<ParsedType>,
+    )
+{
     fn generate_fn_epilog(&self) -> FnEpilogDescriptor {
         FnEpilogDescriptor {
             fn_return_type: generate_fn_return_type(self.2),
@@ -107,7 +113,7 @@ fn generate_epilog(ty: &Option<ParsedType>) -> proc_macro2::TokenStream {
                 fluence::internal::set_result_ptr(result.as_ptr() as _);
                 fluence::internal::set_result_size(result.len() as _);
             }
-        },
+        }
         Some(ParsedType::Vector(ty, _)) => {
             let generated_serializer_name = String::from("__fce_generated_vec_serializer");
             let generated_serializer_ident = new_ident!(generated_serializer_name);
@@ -130,13 +136,18 @@ fn generate_epilog(ty: &Option<ParsedType>) -> proc_macro2::TokenStream {
 /// If an export function returns a reference, probably this reference is to one
 /// of these function arguments. In this case they should preserve after the end
 /// of the function and then deleted by IT with explicitly call of deallocate.
-fn generate_mem_forget(args: &Vec<(String, ParsedType)>, converted_args: &Vec<syn::Ident>, ret_type: &Option<ParsedType>) -> proc_macro2::TokenStream {
-
+fn generate_mem_forget(
+    args: &Vec<(String, ParsedType)>,
+    converted_args: &Vec<syn::Ident>,
+    ret_type: &Option<ParsedType>,
+) -> proc_macro2::TokenStream {
     let passing_style = ret_type.as_ref().map(passing_style_of);
 
     match passing_style {
         Some(PassingStyle::ByValue) => mem_forget_by_ret_type(ret_type),
-        Some(PassingStyle::ByRef) | Some(PassingStyle::ByMutRef) => mem_forget_by_args(args, converted_args),
+        Some(PassingStyle::ByRef) | Some(PassingStyle::ByMutRef) => {
+            mem_forget_by_args(args, converted_args)
+        }
         None => quote! {},
     }
 }
@@ -148,7 +159,10 @@ fn mem_forget_by_ret_type(ret_type: &Option<ParsedType>) -> proc_macro2::TokenSt
     }
 }
 
-fn mem_forget_by_args(args: &Vec<(String, ParsedType)>, converted_args: &Vec<syn::Ident>) -> proc_macro2::TokenStream {
+fn mem_forget_by_args(
+    args: &Vec<(String, ParsedType)>,
+    converted_args: &Vec<syn::Ident>,
+) -> proc_macro2::TokenStream {
     debug_assert!(args.len() == converted_args.len());
 
     let mut res = proc_macro2::TokenStream::new();
@@ -156,7 +170,7 @@ fn mem_forget_by_args(args: &Vec<(String, ParsedType)>, converted_args: &Vec<syn
         let arg_passing_style = passing_style_of(arg);
         match arg_passing_style {
             // such values will be deleted inside an export function because they are being moved
-            PassingStyle::ByValue => {},
+            PassingStyle::ByValue => {}
             _ => res.extend(quote! { std::mem::forget(#converted_arg); }),
         }
     }

crates/wit/src/parsed_type/fn_prolog.rs

@@ -156,7 +156,7 @@ fn generate_type_lifting_prolog(
 
     TypeLifter {
         converted_arg_ident,
-        type_lifter_glue_code
+        type_lifter_glue_code,
     }
 }
 

crates/wit/src/parsed_type/foreign_mod_prolog.rs

@@ -76,6 +76,7 @@ impl ForeignModPrologGlueCodeGenerator for Vec<(String, ParsedType)> {
                 let arg_ident = new_ident!(arg_name);
                 arg_names.push(arg_ident.clone());
 
+                // arguments of following two types shouldn't be deleted after transformation to raw view
                 match ty {
                     ParsedType::Utf8String(PassingStyle::ByValue) => {
                         arg_transforms.extend(quote::quote! { let mut #arg_ident = std::mem::ManuallyDrop::new(#arg_ident); });

crates/wit/src/token_stream_generator/fn_generator.rs

@@ -57,7 +57,12 @@ impl quote::ToTokens for fce_ast_types::AstFunctionItem {
             return_expression,
             epilog,
             mem_forget,
-        } = (&signature.arguments, converted_arg_idents, &signature.output_type).generate_fn_epilog();
+        } = (
+            &signature.arguments,
+            converted_arg_idents,
+            &signature.output_type,
+        )
+            .generate_fn_epilog();
 
         // here this Option must be Some
         let original_func = &self.original;

crates/wit/src/token_stream_generator/foreign_mod_generator.rs

@@ -67,7 +67,8 @@ fn generate_extern_section_items(extern_item: &fce_ast_types::AstExternModItem)
     for import in &extern_item.imports {
         let signature = &import.signature;
 
-        let FnEpilogDescriptor { fn_return_type, .. } = (&vec![], &vec![], &signature.output_type).generate_fn_epilog();
+        let FnEpilogDescriptor { fn_return_type, .. } =
+            (&vec![], &vec![], &signature.output_type).generate_fn_epilog();
 
         let link_name = import.link_name.as_ref().unwrap_or(&signature.name);
         let import_name = generate_import_name(&signature.name);

crates/wit/src/wasm_type.rs

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2020 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 use proc_macro2::TokenStream;
 
 /// Raw Wasm types according to the spec except i128.