Add match-stress benchmark.

This combines the two existing `match-stress-*` benchmarks. They will be
removed soon.

Author: nnethercote

collector/benchmarks/README.md

@@ -81,8 +81,8 @@ compiler in interesting ways.
 - **deep-vector**: A test containing a single large vector of zeroes, which
   caused [poor performance](https://github.com/rust-lang/rust/issues/20936) in
   the past.
-- **derive**: A large amount of simple structs with a `#[derive]` attribute for common built-in traits such as Copy and Debug.
-- **externs**: A large amount of extern functions has caused [slowdowns in the past](https://github.com/rust-lang/rust/pull/78448).
+- **derive**: A large number of simple structs with a `#[derive]` attribute for common built-in traits such as Copy and Debug.
+- **externs**: A large number of extern functions has caused [slowdowns in the past](https://github.com/rust-lang/rust/pull/78448).
 - **issue-46449**: A small program that caused [poor
   performance](https://github.com/rust-lang/rust/issues/46449) in the past.
 - **issue-58319**: A small program that caused [poor
@@ -95,6 +95,11 @@ compiler in interesting ways.
 - **many-assoc-items**: Contains a struct with many associated items, which
   caused [quadratic behavior](https://github.com/rust-lang/rust/issues/68957)
   in the past.
+- **match-stress**: Contains examples 
+  (one involving [a huge enum](https://github.com/rust-lang/rust/issues/7462),
+  one involving
+  [`exhaustive_patterns`](https://github.com/rust-lang/rust/pull/79394)) of
+  `match` code that caused bad performance in the past.
 - **match-stress-enum**: Contains a match against a huge enum, which used to
   have [quadratic runtime](https://github.com/rust-lang/rust/issues/7462).
 - **match-stress-exhaustive_patterns**: Contains code extracted from the `syn`

collector/benchmarks/match-stress/Cargo.lock

@@ -0,0 +1,5 @@
+[package]
+name = "match-stress"
+version = "0.1.0"
+
+[workspace]

collector/benchmarks/match-stress/Cargo.toml

@@ -0,0 +1,4 @@
+{
+    "touch_file": "src/lib.rs",
+    "category": "secondary"
+}

collector/benchmarks/match-stress/perf-config.json

@@ -0,0 +1,78 @@
+use super::*;
+use delimited::Delimited;
+
+ast_enum! {
+    /// Distinguishes between Attributes that decorate items and Attributes that
+    /// are contained as statements within items. These two cases need to be
+    /// distinguished for pretty-printing.
+    pub enum AttrStyle {
+        /// Attribute of the form `#[...]`.
+        Outer,
+
+        /// Attribute of the form `#![...]`.
+        Inner(tokens::Bang),
+    }
+}
+
+ast_enum_of_structs! {
+    /// A compile-time attribute item.
+    ///
+    /// E.g. `#[test]`, `#[derive(..)]` or `#[feature = "foo"]`
+    pub enum MetaItem {
+        /// Term meta item.
+        ///
+        /// E.g. `test` as in `#[test]`
+        pub Term(Ident),
+
+        /// List meta item.
+        ///
+        /// E.g. `derive(..)` as in `#[derive(..)]`
+        pub List(MetaItemList {
+            /// Name of this attribute.
+            ///
+            /// E.g. `derive` in `#[derive(..)]`
+            pub ident: Ident,
+
+            pub paren_token: tokens::Paren,
+
+            /// Arguments to this attribute
+            ///
+            /// E.g. `..` in `#[derive(..)]`
+            pub nested: Delimited,
+        }),
+
+        /// Name-value meta item.
+        ///
+        /// E.g. `feature = "foo"` as in `#[feature = "foo"]`
+        pub NameValue(MetaNameValue {
+            /// Name of this attribute.
+            ///
+            /// E.g. `feature` in `#[feature = "foo"]`
+            pub ident: Ident,
+
+            pub eq_token: tokens::Eq,
+
+            /// Arguments to this attribute
+            ///
+            /// E.g. `"foo"` in `#[feature = "foo"]`
+            pub lit: Lit,
+        }),
+    }
+}
+
+ast_enum_of_structs! {
+    /// Possible values inside of compile-time attribute lists.
+    ///
+    /// E.g. the '..' in `#[name(..)]`.
+    pub enum NestedMetaItem {
+        /// A full `MetaItem`.
+        ///
+        /// E.g. `Copy` in `#[derive(Copy)]` would be a `MetaItem::Term(Ident::from("Copy"))`.
+        pub MetaItem(MetaItem),
+
+        /// A Rust literal.
+        ///
+        /// E.g. `"name"` in `#[rename("name")]`.
+        pub Literal(Lit),
+    }
+}

collector/benchmarks/match-stress/src/attr.rs

@@ -0,0 +1,84 @@
+use super::*;
+use delimited::Delimited;
+
+ast_struct! {
+    /// An enum variant.
+    pub struct Variant {
+        /// Name of the variant.
+        pub ident: Ident,
+
+        /// Attributes tagged on the variant.
+        pub attrs: Vec<u64>,
+
+        /// Type of variant.
+        pub data: VariantData,
+
+        /// Explicit discriminant, e.g. `Foo = 1`
+        pub discriminant: Option<Expr>,
+
+        pub eq_token: Option<tokens::Eq>,
+    }
+}
+
+ast_enum! {
+    /// Data stored within an enum variant or struct.
+    pub enum VariantData {
+        /// Struct variant, e.g. `Point { x: f64, y: f64 }`.
+        Struct(Delimited, tokens::Brace),
+
+        /// Tuple variant, e.g. `Some(T)`.
+        Tuple(Delimited, tokens::Paren),
+
+        /// Unit variant, e.g. `None`.
+        Unit,
+    }
+}
+
+ast_struct! {
+    /// A field of a struct or enum variant.
+    pub struct Field {
+        /// Name of the field, if any.
+        ///
+        /// Fields of tuple structs have no names.
+        pub ident: Option<Ident>,
+
+        /// Visibility of the field.
+        pub vis: Visibility,
+
+        /// Attributes tagged on the field.
+        pub attrs: Vec<u64>,
+
+        /// Type of the field.
+        pub ty: Ty,
+
+        pub colon_token: Option<tokens::Colon>,
+    }
+}
+
+ast_enum_of_structs! {
+    /// Visibility level of an item.
+    pub enum Visibility {
+        /// Public, i.e. `pub`.
+        pub Public(VisPublic {
+            pub pub_token: tokens::Pub,
+        }),
+
+        /// Crate-visible, i.e. `pub(crate)`.
+        pub Crate(VisCrate {
+            pub pub_token: tokens::Pub,
+            pub paren_token: tokens::Paren,
+            pub crate_token: tokens::Crate,
+        }),
+
+        /// Restricted, e.g. `pub(self)` or `pub(super)` or `pub(in some::module)`.
+        pub Restricted(VisRestricted {
+            pub pub_token: tokens::Pub,
+            pub paren_token: tokens::Paren,
+            pub in_token: Option<tokens::In>,
+            pub path: Box<u64>,
+        }),
+
+        /// Inherited, i.e. private.
+        pub Inherited(VisInherited {}),
+    }
+}