crates/mbe/src/benchmark.rs

   1 //! This module add real world mbe example for benchmark tests
   2
   3 use rustc_hash::FxHashMap;
   4 use syntax::{
   5     ast::{self, NameOwner},
   6     AstNode, SmolStr,
   7 };
   8 use test_utils::{bench, bench_fixture, skip_slow_tests};
   9
  10 use crate::{
  11     ast_to_token_tree,
  12     parser::{Op, RepeatKind, Separator},
  13     MacroRules,
  14 };
  15
  16 #[test]
  17 fn benchmark_parse_macro_rules() {
  18     if skip_slow_tests() {
  19         return;
  20     }
  21     let rules = macro_rules_fixtures_tt();
  22     let hash: usize = {
  23         let _pt = bench("mbe parse macro rules");
  24         rules.values().map(|it| MacroRules::parse(it).unwrap().rules.len()).sum()
  25     };
  26     assert_eq!(hash, 1144);
  27 }
  28
  29 #[test]
  30 fn benchmark_expand_macro_rules() {
  31     if skip_slow_tests() {
  32         return;
  33     }
  34     let rules = macro_rules_fixtures();
  35     let invocations = invocation_fixtures(&rules);
  36
  37     let hash: usize = {
  38         let _pt = bench("mbe expand macro rules");
  39         invocations
  40             .into_iter()
  41             .map(|(id, tt)| {
  42                 let res = rules[&id].expand(&tt);
  43                 assert!(res.err.is_none());
  44                 res.value.token_trees.len()
  45             })
  46             .sum()
  47     };
  48     assert_eq!(hash, 69413);
  49 }
  50
  51 fn macro_rules_fixtures() -> FxHashMap<String, MacroRules> {
  52     macro_rules_fixtures_tt()
  53         .into_iter()
  54         .map(|(id, tt)| (id, MacroRules::parse(&tt).unwrap()))
  55         .collect()
  56 }
  57
  58 fn macro_rules_fixtures_tt() -> FxHashMap<String, tt::Subtree> {
  59     let fixture = bench_fixture::numerous_macro_rules();
  60     let source_file = ast::SourceFile::parse(&fixture).ok().unwrap();
  61
  62     source_file
  63         .syntax()
  64         .descendants()
  65         .filter_map(ast::MacroRules::cast)
  66         .map(|rule| {
  67             let id = rule.name().unwrap().to_string();
  68             let (def_tt, _) = ast_to_token_tree(&rule.token_tree().unwrap());
  69             (id, def_tt)
  70         })
  71         .collect()
  72 }
  73
  74 /// Generate random invocation fixtures from rules
  75 fn invocation_fixtures(rules: &FxHashMap<String, MacroRules>) -> Vec<(String, tt::Subtree)> {
  76     let mut seed = 123456789;
  77     let mut res = Vec::new();
  78
  79     for (name, it) in rules {
  80         for rule in &it.rules {
  81             // Generate twice
  82             for _ in 0..2 {
  83                 // The input are generated by filling the `Op` randomly.
  84                 // However, there are some cases generated are ambiguous for expanding, for example:
  85                 // ```rust
  86                 // macro_rules! m {
  87                 //    ($($t:ident),* as $ty:ident) => {}
  88                 // }
  89                 // m!(as u32);  // error: local ambiguity: multiple parsing options: built-in NTs ident ('t') or 1 other option.
  90                 // ```
  91                 //
  92                 // So we just skip any error cases and try again
  93                 let mut try_cnt = 0;
  94                 loop {
  95                     let mut subtree = tt::Subtree::default();
  96                     for op in rule.lhs.iter() {
  97                         collect_from_op(op, &mut subtree, &mut seed);
  98                     }
  99                     if it.expand(&subtree).err.is_none() {
 100                         res.push((name.clone(), subtree));
 101                         break;
 102                     }
 103                     try_cnt += 1;
 104                     if try_cnt > 100 {
 105                         panic!("invocaton fixture {} cannot be generated.\n", name);
 106                     }
 107                 }
 108             }
 109         }
 110     }
 111     return res;
 112
 113     fn collect_from_op(op: &Op, parent: &mut tt::Subtree, seed: &mut usize) {
 114         return match op {
 115             Op::Var { kind, .. } => match kind.as_ref().map(|it| it.as_str()) {
 116                 Some("ident") => parent.token_trees.push(make_ident("foo")),
 117                 Some("ty") => parent.token_trees.push(make_ident("Foo")),
 118                 Some("tt") => parent.token_trees.push(make_ident("foo")),
 119                 Some("vis") => parent.token_trees.push(make_ident("pub")),
 120                 Some("pat") => parent.token_trees.push(make_ident("foo")),
 121                 Some("path") => parent.token_trees.push(make_ident("foo")),
 122                 Some("literal") => parent.token_trees.push(make_literal("1")),
 123                 Some("expr") => parent.token_trees.push(make_ident("foo")),
 124                 Some("lifetime") => {
 125                     parent.token_trees.push(make_punct('\''));
 126                     parent.token_trees.push(make_ident("a"));
 127                 }
 128                 Some("block") => {
 129                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Brace, None))
 130                 }
 131                 Some("item") => {
 132                     parent.token_trees.push(make_ident("fn"));
 133                     parent.token_trees.push(make_ident("foo"));
 134                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Parenthesis, None));
 135                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Brace, None));
 136                 }
 137                 Some("meta") => {
 138                     parent.token_trees.push(make_ident("foo"));
 139                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Parenthesis, None));
 140                 }
 141
 142                 None => (),
 143                 Some(kind) => panic!("Unhandled kind {}", kind),
 144             },
 145             Op::Leaf(leaf) => parent.token_trees.push(leaf.clone().into()),
 146             Op::Repeat { tokens, kind, separator } => {
 147                 let max = 10;
 148                 let cnt = match kind {
 149                     RepeatKind::ZeroOrMore => rand(seed) % max,
 150                     RepeatKind::OneOrMore => 1 + rand(seed) % max,
 151                     RepeatKind::ZeroOrOne => rand(seed) % 2,
 152                 };
 153                 for i in 0..cnt {
 154                     for it in tokens.iter() {
 155                         collect_from_op(it, parent, seed);
 156                     }
 157                     if i + 1 != cnt {
 158                         if let Some(sep) = separator {
 159                             match sep {
 160                                 Separator::Literal(it) => {
 161                                     parent.token_trees.push(tt::Leaf::Literal(it.clone()).into())
 162                                 }
 163                                 Separator::Ident(it) => {
 164                                     parent.token_trees.push(tt::Leaf::Ident(it.clone()).into())
 165                                 }
 166                                 Separator::Puncts(puncts) => {
 167                                     for it in puncts {
 168                                         parent.token_trees.push(tt::Leaf::Punct(*it).into())
 169                                     }
 170                                 }
 171                             };
 172                         }
 173                     }
 174                 }
 175             }
 176             Op::Subtree { tokens, delimiter } => {
 177                 let mut subtree = tt::Subtree { delimiter: *delimiter, token_trees: Vec::new() };
 178                 tokens.iter().for_each(|it| {
 179                     collect_from_op(it, &mut subtree, seed);
 180                 });
 181                 parent.token_trees.push(subtree.into());
 182             }
 183         };
 184
 185         // Simple linear congruential generator for determistic result
 186         fn rand(seed: &mut usize) -> usize {
 187             let a = 1664525;
 188             let c = 1013904223;
 189             *seed = usize::wrapping_add(usize::wrapping_mul(*seed, a), c);
 190             *seed
 191         }
 192         fn make_ident(ident: &str) -> tt::TokenTree {
 193             tt::Leaf::Ident(tt::Ident { id: tt::TokenId::unspecified(), text: SmolStr::new(ident) })
 194                 .into()
 195         }
 196         fn make_punct(char: char) -> tt::TokenTree {
 197             tt::Leaf::Punct(tt::Punct {
 198                 id: tt::TokenId::unspecified(),
 199                 char,
 200                 spacing: tt::Spacing::Alone,
 201             })
 202             .into()
 203         }
 204         fn make_literal(lit: &str) -> tt::TokenTree {
 205             tt::Leaf::Literal(tt::Literal {
 206                 id: tt::TokenId::unspecified(),
 207                 text: SmolStr::new(lit),
 208             })
 209             .into()
 210         }
 211         fn make_subtree(
 212             kind: tt::DelimiterKind,
 213             token_trees: Option<Vec<tt::TokenTree>>,
 214         ) -> tt::TokenTree {
 215             tt::Subtree {
 216                 delimiter: Some(tt::Delimiter { id: tt::TokenId::unspecified(), kind }),
 217                 token_trees: token_trees.unwrap_or_default(),
 218             }
 219             .into()
 220         }
 221     }
 222 }