fix: Prevent combinatorial explosion in test_parse

Author: skogseth

crates/libtest2/src/lib.rs

@@ -60,6 +60,7 @@ pub mod _private {
     pub use libtest2_harness::TestKind;
 
     pub use crate::_main_parse as main_parse;
+    pub use crate::_parse_ignore as parse_ignore;
     pub use crate::_test_parse as test_parse;
     pub use crate::case::DynCase;
 }

crates/libtest2/src/macros.rs

@@ -26,72 +26,35 @@ macro_rules! _test_parse {
     };
 
     // Recursively handle attributes
-    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$state:expr)?) => {
+    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$ignore:tt)?) => {
         $crate::_private::test_parse! {
             name=$name
             body=[$($item)*]
             attrs=[$(#[$parsed_attr])*]
-            $(ignore=$state)?
+            $(ignore=$ignore)?
         }
     };
-    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[#[ignore] $(#[$($unparsed_attr:tt)+])*] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$state:expr)?) => {
+    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[#[ignore $(= $reason:literal)?] $(#[$($unparsed_attr:tt)+])*] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$ignore:tt)?) => {
         $crate::_private::test_parse! {
             name=$name
             body=[$($item)*]
             unparsed_attrs=[$(#[$($unparsed_attr)*])*]
             parsed_attrs=[$(#[$parsed_attr])*]
-            ignore=()
+            ignore=[$($reason)?]
         }
     };
-    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[#[ignore = $reason:literal] $(#[$($unparsed_attr:tt)+])*] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$state:expr)?) => {
-        $crate::_private::test_parse! {
-            name=$name
-            body=[$($item)*]
-            unparsed_attrs=[$(#[$($unparsed_attr)*])*]
-            parsed_attrs=[$(#[$parsed_attr])*]
-            ignore=$reason
-        }
-    };
-    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[#[$($attr:tt)+] $(#[$($unparsed_attr:tt)+])*] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$state:expr)?) => {
+    (name=$name:ident body=[$($item:tt)*] unparsed_attrs=[#[$($attr:tt)+] $(#[$($unparsed_attr:tt)+])*] parsed_attrs=[$(#[$parsed_attr:meta])*] $(ignore=$ignore:tt)?) => {
         $crate::_private::test_parse! {
             name=$name
             body=[$($item)*]
             unparsed_attrs=[$(#[$($unparsed_attr)*])*]
             parsed_attrs=[#[$($attr)* $(#[$($parsed_attr)*])*]]
-            $(ignore=$state)?
+            $(ignore=$ignore)?
         }
     };
 
     // End result
-    (name=$name:ident body=[$($item:tt)*] attrs=[$(#[$attr:meta])*]) => {
-        #[allow(non_camel_case_types)]
-        struct $name;
-
-        impl $crate::_private::Case for $name {
-            fn name(&self) -> &str {
-                $crate::_private::push!(crate::TESTS, _: $crate::_private::DynCase = $crate::_private::DynCase(&$name));
-
-                stringify!($name)
-            }
-            fn kind(&self) -> $crate::_private::TestKind {
-                Default::default()
-            }
-            fn source(&self) -> Option<&$crate::_private::Source> {
-                None
-            }
-            fn exclusive(&self, _: &$crate::TestContext) -> bool {
-                false
-            }
-
-            fn run(&self, context: &$crate::TestContext) -> $crate::RunResult {
-                $(#[$attr])*
-                fn run $($item)*
-
-                run(context)
-            }
-        }
-    };
-    (name=$name:ident body=[$($item:tt)*] attrs=[$(#[$attr:meta])*] ignore=$reason:literal) => {
+    (name=$name:ident body=[$($item:tt)*] attrs=[$(#[$attr:meta])*] $(ignore=$ignore:tt)?) => {
         #[allow(non_camel_case_types)]
         struct $name;
 
@@ -115,37 +78,9 @@ macro_rules! _test_parse {
                 $(#[$attr])*
                 fn run $($item)*
 
-                context.ignore_for($reason)?;
-
-                run(context)
-            }
-        }
-    };
-    (name=$name:ident body=[$($item:tt)*] attrs=[$(#[$attr:meta])*] ignore=$unused:expr) => {
-        #[allow(non_camel_case_types)]
-        struct $name;
-
-        impl $crate::_private::Case for $name {
-            fn name(&self) -> &str {
-                $crate::_private::push!(crate::TESTS, _: $crate::_private::DynCase = $crate::_private::DynCase(&$name));
-
-                stringify!($name)
-            }
-            fn kind(&self) -> $crate::_private::TestKind {
-                Default::default()
-            }
-            fn source(&self) -> Option<&$crate::_private::Source> {
-                None
-            }
-            fn exclusive(&self, _: &$crate::TestContext) -> bool {
-                false
-            }
-
-            fn run(&self, context: &$crate::TestContext) -> $crate::RunResult {
-                $(#[$attr])*
-                fn run $($item)*
-
-                context.ignore()?;
+                $(
+                    $crate::_private::parse_ignore!($ignore, context)?;
+                )?
 
                 use $crate::IntoRunResult;
                 let result = run(context);
@@ -154,3 +89,14 @@ macro_rules! _test_parse {
         }
     };
 }
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! _parse_ignore {
+    ([$reason:literal], $context:expr) => {
+        $context.ignore_for($reason)
+    };
+    ([], $context:expr) => {
+        $context.ignore()
+    };
+}