1 //! Test case generators.
2 //!
3 //! Test case generators take raw, unstructured input from a fuzzer
4 //! (e.g. libFuzzer) and translate that into a structured test case (e.g. a
5 //! valid Wasm binary).
6 //!
7 //! These are generally implementations of the `Arbitrary` trait, or some
8 //! wrapper over an external tool, such that the wrapper implements the
9 //! `Arbitrary` trait for the wrapped external tool.
10 
11 pub mod api;
12 
13 pub mod table_ops;
14 
15 use arbitrary::{Arbitrary, Unstructured};
16 
17 /// A description of configuration options that we should do differential
18 /// testing between.
19 #[derive(Arbitrary, Clone, Debug, PartialEq, Eq, Hash)]
20 pub struct DifferentialConfig {
21     strategy: DifferentialStrategy,
22     opt_level: OptLevel,
23 }
24 
25 impl DifferentialConfig {
26     /// Convert this differential fuzzing config into a `wasmtime::Config`.
27     pub fn to_wasmtime_config(&self) -> anyhow::Result<wasmtime::Config> {
28         let mut config = crate::fuzz_default_config(match self.strategy {
29             DifferentialStrategy::Cranelift => wasmtime::Strategy::Cranelift,
30             DifferentialStrategy::Lightbeam => wasmtime::Strategy::Lightbeam,
31         })?;
32         config.cranelift_opt_level(self.opt_level.to_wasmtime());
33         Ok(config)
34     }
35 }
36 
37 #[derive(Arbitrary, Clone, Debug, PartialEq, Eq, Hash)]
38 enum DifferentialStrategy {
39     Cranelift,
40     Lightbeam,
41 }
42 
43 #[derive(Arbitrary, Clone, Debug, PartialEq, Eq, Hash)]
44 enum OptLevel {
45     None,
46     Speed,
47     SpeedAndSize,
48 }
49 
50 impl OptLevel {
51     fn to_wasmtime(&self) -> wasmtime::OptLevel {
52         match self {
53             OptLevel::None => wasmtime::OptLevel::None,
54             OptLevel::Speed => wasmtime::OptLevel::Speed,
55             OptLevel::SpeedAndSize => wasmtime::OptLevel::SpeedAndSize,
56         }
57     }
58 }
59 
60 /// Implementation of generating a `wasmtime::Config` arbitrarily
61 #[derive(Arbitrary, Debug)]
62 pub struct Config {
63     opt_level: OptLevel,
64     debug_info: bool,
65     canonicalize_nans: bool,
66     interruptable: bool,
67     #[allow(missing_docs)]
68     pub consume_fuel: bool,
69 
70     // Note that we use 32-bit values here to avoid blowing the 64-bit address
71     // space by requesting ungodly-large sizes/guards.
72     static_memory_maximum_size: Option<u32>,
73     static_memory_guard_size: Option<u32>,
74     dynamic_memory_guard_size: Option<u32>,
75 }
76 
77 impl Config {
78     /// Converts this to a `wasmtime::Config` object
79     pub fn to_wasmtime(&self) -> wasmtime::Config {
80         let mut cfg = crate::fuzz_default_config(wasmtime::Strategy::Auto).unwrap();
81         cfg.debug_info(self.debug_info)
82             .static_memory_maximum_size(self.static_memory_maximum_size.unwrap_or(0).into())
83             .static_memory_guard_size(self.static_memory_guard_size.unwrap_or(0).into())
84             .dynamic_memory_guard_size(self.dynamic_memory_guard_size.unwrap_or(0).into())
85             .cranelift_nan_canonicalization(self.canonicalize_nans)
86             .cranelift_opt_level(self.opt_level.to_wasmtime())
87             .interruptable(self.interruptable)
88             .consume_fuel(self.consume_fuel);
89         return cfg;
90     }
91 }
92 
93 include!(concat!(env!("OUT_DIR"), "/spectests.rs"));
94 
95 /// A spec test from the upstream wast testsuite, arbitrarily chosen from the
96 /// list of known spec tests.
97 #[derive(Debug)]
98 pub struct SpecTest {
99     /// The filename of the spec test
100     pub file: &'static str,
101     /// The `*.wast` contents of the spec test
102     pub contents: &'static str,
103 }
104 
105 impl<'a> Arbitrary<'a> for SpecTest {
106     fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
107         // NB: this does get a uniform value in the provided range.
108         let i = u.int_in_range(0..=FILES.len() - 1)?;
109         let (file, contents) = FILES[i];
110         Ok(SpecTest { file, contents })
111     }
112 
113     fn size_hint(_depth: usize) -> (usize, Option<usize>) {
114         (1, Some(std::mem::size_of::<usize>()))
115     }
116 }
117