1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145

//! Configuring the shape of generated Wasm modules.

use arbitrary::{Arbitrary, Result, Unstructured};

/// Configuration for a generated module.
///
/// Don't care to configure your generated modules? Just use
/// [`Module`][crate::Module], which internally uses
/// [`DefaultConfig`][crate::DefaultConfig].
///
/// If you want to configure generated modules, then define a `MyConfig` type,
/// implement this trait for it, and use
/// [`ConfiguredModule<MyConfig>`][crate::ConfiguredModule] instead of `Module`.
///
/// Every trait method has a provided default implementation, so that you only
/// need to override the methods for things you want to change away from the
/// default.
pub trait Config: Arbitrary + Default {
    /// The maximum number of imports to generate. Defaults to 100.
    fn max_imports(&self) -> usize {
        100
    }

    /// The maximum number of functions to generate. Defaults to 100.
    fn max_funcs(&self) -> usize {
        100
    }

    /// The maximum number of globals to generate. Defaults to 100.
    fn max_globals(&self) -> usize {
        100
    }

    /// The maximum number of exports to generate. Defaults to 100.
    fn max_exports(&self) -> usize {
        100
    }

    /// The maximum number of element segments to generate. Defaults to 100.
    fn max_element_segments(&self) -> usize {
        100
    }

    /// The maximum number of elements within a segment to generate. Defaults to
    /// 100.
    fn max_elements(&self) -> usize {
        100
    }

    /// The maximum number of data segments to generate. Defaults to 100.
    fn max_data_segments(&self) -> usize {
        100
    }

    /// The maximum number of instructions to generate in a function
    /// body. Defaults to 100.
    ///
    /// Note that some additional `end`s, `else`s, and `unreachable`s may be
    /// appended to the function body to finish block scopes.
    fn max_instructions(&self) -> usize {
        100
    }

    /// The maximum number of memories to use. Defaults to 1.
    ///
    /// Note that more than one memory is in the realm of the multi-memory wasm
    /// proposal.
    fn max_memories(&self) -> u32 {
        1
    }
}

/// The default configuration.
#[derive(Arbitrary, Debug, Default, Copy, Clone)]
pub struct DefaultConfig;

impl Config for DefaultConfig {}

/// A module configuration that uses [swarm testing].
///
/// Dynamically -- but still deterministically, via its `Arbitrary`
/// implementation -- chooses configuration options.
///
/// [swarm testing]: https://www.cs.utah.edu/~regehr/papers/swarm12.pdf
#[derive(Clone, Debug, Default)]
pub struct SwarmConfig {
    max_imports: usize,
    max_funcs: usize,
    max_globals: usize,
    max_exports: usize,
    max_element_segments: usize,
    max_elements: usize,
    max_data_segments: usize,
    max_instructions: usize,
}

impl Arbitrary for SwarmConfig {
    fn arbitrary(u: &mut Unstructured<'_>) -> Result<Self> {
        const MAX_MAXIMUM: usize = 1000;
        Ok(SwarmConfig {
            max_imports: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_funcs: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_globals: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_exports: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_element_segments: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_elements: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_data_segments: u.int_in_range(0..=MAX_MAXIMUM)?,
            max_instructions: u.int_in_range(0..=MAX_MAXIMUM)?,
        })
    }
}

impl Config for SwarmConfig {
    fn max_imports(&self) -> usize {
        self.max_imports
    }

    fn max_funcs(&self) -> usize {
        self.max_funcs
    }

    fn max_globals(&self) -> usize {
        self.max_globals
    }

    fn max_exports(&self) -> usize {
        self.max_exports
    }

    fn max_element_segments(&self) -> usize {
        self.max_element_segments
    }

    fn max_elements(&self) -> usize {
        self.max_elements
    }

    fn max_data_segments(&self) -> usize {
        self.max_data_segments
    }

    fn max_instructions(&self) -> usize {
        self.max_instructions
    }
}