macros: improve error messages (#1420)

This commit is contained in:
Taiki Endo
2019-08-09 10:28:22 -07:00
committed by Carl Lerche
parent 73102760cf
commit f7b41c9dcc
+27 -28
View File
@@ -7,8 +7,7 @@
extern crate proc_macro; extern crate proc_macro;
use proc_macro::TokenStream; use proc_macro::TokenStream;
use quote::{quote, quote_spanned}; use quote::quote;
use syn::spanned::Spanned;
/// Marks async function to be executed by selected runtime. /// Marks async function to be executed by selected runtime.
/// ///
@@ -56,17 +55,15 @@ pub fn main(args: TokenStream, item: TokenStream) -> TokenStream {
let attrs = &input.attrs; let attrs = &input.attrs;
if input.asyncness.is_none() { if input.asyncness.is_none() {
let tokens = quote_spanned! { input.span() => let msg = "the async keyword is missing from the function declaration";
compile_error!("the async keyword is missing from the function declaration"); return syn::Error::new_spanned(input.decl.fn_token, msg)
}; .to_compile_error()
.into();
return TokenStream::from(tokens);
} else if !input.decl.inputs.is_empty() { } else if !input.decl.inputs.is_empty() {
let tokens = quote_spanned! { input.span() => let msg = "the main function cannot accept arguments";
compile_error!("the main function cannot accept arguments"); return syn::Error::new_spanned(&input.decl.inputs, msg)
}; .to_compile_error()
.into();
return TokenStream::from(tokens);
} }
let mut runtime = RuntimeType::Multi; let mut runtime = RuntimeType::Multi;
@@ -76,7 +73,12 @@ pub fn main(args: TokenStream, item: TokenStream) -> TokenStream {
match ident.to_string().to_lowercase().as_str() { match ident.to_string().to_lowercase().as_str() {
"multi_thread" => runtime = RuntimeType::Multi, "multi_thread" => runtime = RuntimeType::Multi,
"single_thread" => runtime = RuntimeType::Single, "single_thread" => runtime = RuntimeType::Single,
name => panic!("Unknown attribute {} is specified", name), name => {
let msg = format!("Unknown attribute {} is specified", name);
return syn::Error::new_spanned(ident, msg)
.to_compile_error()
.into();
}
} }
} }
} }
@@ -126,26 +128,23 @@ pub fn test(_attr: TokenStream, item: TokenStream) -> TokenStream {
for attr in attrs { for attr in attrs {
if attr.path.is_ident("test") { if attr.path.is_ident("test") {
let tokens = quote_spanned! { input.span() => let msg = "second test attribute is supplied";
compile_error!("second test attribute is supplied"); return syn::Error::new_spanned(&attr, msg)
}; .to_compile_error()
.into();
return TokenStream::from(tokens);
} }
} }
if input.asyncness.is_none() { if input.asyncness.is_none() {
let tokens = quote_spanned! { input.span() => let msg = "the async keyword is missing from the function declaration";
compile_error!("the async keyword is missing from the function declaration"); return syn::Error::new_spanned(&input, msg)
}; .to_compile_error()
.into();
return TokenStream::from(tokens);
} else if !input.decl.inputs.is_empty() { } else if !input.decl.inputs.is_empty() {
let tokens = quote_spanned! { input.span() => let msg = "the test function cannot accept arguments";
compile_error!("the test function cannot accept arguments"); return syn::Error::new_spanned(&input.decl.inputs, msg)
}; .to_compile_error()
.into();
return TokenStream::from(tokens);
} }
let result = quote! { let result = quote! {