Prevent macro ambiguity errors

The previous macro_rules! parsers failed when an additional modifier was added
with ambiguity errors. The error is pretty unclear as to what exactly the cause
here is, but this change simplifies the argument parsing code such that the
error is avoided.

Author: bjorn3

compiler/rustc_macros/src/query.rs

@@ -455,28 +455,28 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream {
 
         // Pass on the fatal_cycle modifier
         if let Some(fatal_cycle) = &modifiers.fatal_cycle {
-            attributes.push(quote! { #fatal_cycle });
+            attributes.push(quote! { (#fatal_cycle) });
         };
         // Pass on the storage modifier
         if let Some(ref ty) = modifiers.storage {
             let span = ty.span();
-            attributes.push(quote_spanned! {span=> storage(#ty) });
+            attributes.push(quote_spanned! {span=> (storage #ty) });
         };
         // Pass on the cycle_delay_bug modifier
         if let Some(cycle_delay_bug) = &modifiers.cycle_delay_bug {
-            attributes.push(quote! { #cycle_delay_bug });
+            attributes.push(quote! { (#cycle_delay_bug) });
         };
         // Pass on the no_hash modifier
         if let Some(no_hash) = &modifiers.no_hash {
-            attributes.push(quote! { #no_hash });
+            attributes.push(quote! { (#no_hash) });
         };
         // Pass on the anon modifier
         if let Some(anon) = &modifiers.anon {
-            attributes.push(quote! { #anon });
+            attributes.push(quote! { (#anon) });
         };
         // Pass on the eval_always modifier
         if let Some(eval_always) = &modifiers.eval_always {
-            attributes.push(quote! { #eval_always });
+            attributes.push(quote! { (#eval_always) });
         };
 
         // This uses the span of the query definition for the commas,

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -140,11 +140,11 @@ macro_rules! is_eval_always_attr {
 }
 
 macro_rules! contains_anon_attr {
-    ($($attr:ident $(($($attr_args:tt)*))* ),*) => ({$(is_anon_attr!($attr) | )* false});
+    ($(($attr:ident $($attr_args:tt)* )),*) => ({$(is_anon_attr!($attr) | )* false});
 }
 
 macro_rules! contains_eval_always_attr {
-    ($($attr:ident $(($($attr_args:tt)*))* ),*) => ({$(is_eval_always_attr!($attr) | )* false});
+    ($(($attr:ident $($attr_args:tt)* )),*) => ({$(is_eval_always_attr!($attr) | )* false});
 }
 
 #[allow(non_upper_case_globals)]

compiler/rustc_middle/src/ty/query.rs

@@ -111,11 +111,11 @@ macro_rules! query_storage {
     ([][$K:ty, $V:ty]) => {
         <DefaultCacheSelector as CacheSelector<$K, $V>>::Cache
     };
-    ([storage($ty:ty) $($rest:tt)*][$K:ty, $V:ty]) => {
+    ([(storage $ty:ty) $($rest:tt)*][$K:ty, $V:ty]) => {
         <$ty as CacheSelector<$K, $V>>::Cache
     };
-    ([$other:ident $(($($other_args:tt)*))* $(, $($modifiers:tt)*)*][$($args:tt)*]) => {
-        query_storage!([$($($modifiers)*)*][$($args)*])
+    ([$other:tt $($modifiers:tt)*][$($args:tt)*]) => {
+        query_storage!([$($modifiers)*][$($args)*])
     };
 }
 

compiler/rustc_query_impl/src/plumbing.rs

@@ -253,53 +253,53 @@ macro_rules! handle_cycle_error {
         $error.emit();
         Value::from_cycle_error($tcx)
     }};
-    ([fatal_cycle $($rest:tt)*][$tcx:expr, $error:expr]) => {{
+    ([(fatal_cycle) $($rest:tt)*][$tcx:expr, $error:expr]) => {{
         $error.emit();
         $tcx.sess.abort_if_errors();
         unreachable!()
     }};
-    ([cycle_delay_bug $($rest:tt)*][$tcx:expr, $error:expr]) => {{
+    ([(cycle_delay_bug) $($rest:tt)*][$tcx:expr, $error:expr]) => {{
         $error.delay_as_bug();
         Value::from_cycle_error($tcx)
     }};
-    ([$other:ident $(($($other_args:tt)*))* $(, $($modifiers:tt)*)*][$($args:tt)*]) => {
-        handle_cycle_error!([$($($modifiers)*)*][$($args)*])
+    ([$other:tt $($modifiers:tt)*][$($args:tt)*]) => {
+        handle_cycle_error!([$($modifiers)*][$($args)*])
     };
 }
 
 macro_rules! is_anon {
     ([]) => {{
         false
     }};
-    ([anon $($rest:tt)*]) => {{
+    ([(anon) $($rest:tt)*]) => {{
         true
     }};
-    ([$other:ident $(($($other_args:tt)*))* $(, $($modifiers:tt)*)*]) => {
-        is_anon!([$($($modifiers)*)*])
+    ([$other:tt $($modifiers:tt)*]) => {
+        is_anon!([$($modifiers)*])
     };
 }
 
 macro_rules! is_eval_always {
     ([]) => {{
         false
     }};
-    ([eval_always $($rest:tt)*]) => {{
+    ([(eval_always) $($rest:tt)*]) => {{
         true
     }};
-    ([$other:ident $(($($other_args:tt)*))* $(, $($modifiers:tt)*)*]) => {
-        is_eval_always!([$($($modifiers)*)*])
+    ([$other:tt $($modifiers:tt)*]) => {
+        is_eval_always!([$($modifiers)*])
     };
 }
 
 macro_rules! hash_result {
     ([][$hcx:expr, $result:expr]) => {{
         dep_graph::hash_result($hcx, &$result)
     }};
-    ([no_hash $($rest:tt)*][$hcx:expr, $result:expr]) => {{
+    ([(no_hash) $($rest:tt)*][$hcx:expr, $result:expr]) => {{
         None
     }};
-    ([$other:ident $(($($other_args:tt)*))* $(, $($modifiers:tt)*)*][$($args:tt)*]) => {
-        hash_result!([$($($modifiers)*)*][$($args)*])
+    ([$other:tt $($modifiers:tt)*][$($args:tt)*]) => {
+        hash_result!([$($modifiers)*][$($args)*])
     };
 }