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

/// Helper macro to iterate over all builtin functions and their signatures.
#[macro_export]
macro_rules! foreach_builtin_function {
    ($mac:ident) => {
        $mac! {
            /// Returns an index for wasm's `memory.grow` builtin function.
            memory32_grow(vmctx: vmctx, delta: i64, index: i32) -> pointer;
            /// Returns an index for wasm's `table.copy` when both tables are locally
            /// defined.
            table_copy(vmctx: vmctx, dst_index: i32, src_index: i32, dst: i32, src: i32, len: i32);
            /// Returns an index for wasm's `table.init`.
            table_init(vmctx: vmctx, table: i32, elem: i32, dst: i32, src: i32, len: i32);
            /// Returns an index for wasm's `elem.drop`.
            elem_drop(vmctx: vmctx, elem: i32);
            /// Returns an index for wasm's `memory.copy`
            memory_copy(vmctx: vmctx, dst_index: i32, dst: i64, src_index: i32, src: i64, len: i64);
            /// Returns an index for wasm's `memory.fill` instruction.
            memory_fill(vmctx: vmctx, memory: i32, dst: i64, val: i32, len: i64);
            /// Returns an index for wasm's `memory.init` instruction.
            memory_init(vmctx: vmctx, memory: i32, data: i32, dst: i64, src: i32, len: i32);
            /// Returns a value for wasm's `ref.func` instruction.
            ref_func(vmctx: vmctx, func: i32) -> pointer;
            /// Returns an index for wasm's `data.drop` instruction.
            data_drop(vmctx: vmctx, data: i32);
            /// Returns a table entry after lazily initializing it.
            table_get_lazy_init_func_ref(vmctx: vmctx, table: i32, index: i32) -> pointer;
            /// Returns an index for Wasm's `table.grow` instruction for `funcref`s.
            table_grow_func_ref(vmctx: vmctx, table: i32, delta: i32, init: pointer) -> i32;
            /// Returns an index for Wasm's `table.grow` instruction for `externref`s.
            table_grow_externref(vmctx: vmctx, table: i32, delta: i32, init: reference) -> i32;
            /// Returns an index for Wasm's `table.fill` instruction for `externref`s.
            table_fill_externref(vmctx: vmctx, table: i32, dst: i32, val: reference, len: i32);
            /// Returns an index for Wasm's `table.fill` instruction for `funcref`s.
            table_fill_func_ref(vmctx: vmctx, table: i32, dst: i32, val: pointer, len: i32);
            /// Returns an index to drop a `VMExternRef`.
            drop_externref(vmctx: vmctx, val: pointer);
            /// Returns an index to do a GC and then insert a `VMExternRef` into the
            /// `VMExternRefActivationsTable`.
            activations_table_insert_with_gc(vmctx: vmctx, val: reference);
            /// Returns an index for Wasm's `global.get` instruction for `externref`s.
            externref_global_get(vmctx: vmctx, global: i32) -> reference;
            /// Returns an index for Wasm's `global.get` instruction for `externref`s.
            externref_global_set(vmctx: vmctx, global: i32, val: reference);
            /// Returns an index for wasm's `memory.atomic.notify` instruction.
            memory_atomic_notify(vmctx: vmctx, memory: i32, addr: i64, count: i32) -> i32;
            /// Returns an index for wasm's `memory.atomic.wait32` instruction.
            memory_atomic_wait32(vmctx: vmctx, memory: i32, addr: i64, expected: i32, timeout: i64) -> i32;
            /// Returns an index for wasm's `memory.atomic.wait64` instruction.
            memory_atomic_wait64(vmctx: vmctx, memory: i32, addr: i64, expected: i64, timeout: i64) -> i32;
            /// Invoked when fuel has run out while executing a function.
            out_of_gas(vmctx: vmctx);
            /// Invoked when we reach a new epoch.
            new_epoch(vmctx: vmctx) -> i64;
            /// Invoked before malloc returns.
            check_malloc(vmctx: vmctx, addr: i32, len: i32) -> i32;
            /// Invoked before the free returns.
            check_free(vmctx: vmctx, addr: i32) -> i32;
            /// Invoked before a load is executed.
            check_load(vmctx: vmctx, num_bytes: i32, addr: i32, offset: i32) -> i32;
            /// Invoked before a store is executed.
            check_store(vmctx: vmctx, num_bytes: i32, addr: i32, offset: i32) -> i32;
            /// Invoked after malloc is called.
            malloc_start(vmctx: vmctx);
            /// Invoked after free is called.
            free_start(vmctx: vmctx);
            /// Invoked when wasm stack pointer is updated.
            update_stack_pointer(vmctx: vmctx, value: i32);
            /// Invoked before memory.grow is called.
            update_mem_size(vmctx: vmctx, num_bytes: i32);
        }
    };
}

/// An index type for builtin functions.
#[derive(Copy, Clone, Debug)]
pub struct BuiltinFunctionIndex(u32);

impl BuiltinFunctionIndex {
    /// Create a new `BuiltinFunctionIndex` from its index
    pub const fn from_u32(i: u32) -> Self {
        Self(i)
    }

    /// Return the index as an u32 number.
    pub const fn index(&self) -> u32 {
        self.0
    }
}

macro_rules! declare_indexes {
    (
        $(
            $( #[$attr:meta] )*
            $name:ident( $( $pname:ident: $param:ident ),* ) $( -> $result:ident )?;
        )*
    ) => {
        impl BuiltinFunctionIndex {
            declare_indexes!(
                @indices;
                0;
                $( $( #[$attr] )* $name; )*
            );
        }
    };

    // Base case: no more indices to declare, so define the total number of
    // function indices.
    (
        @indices;
        $len:expr;
    ) => {
        /// Returns the total number of builtin functions.
        pub const fn builtin_functions_total_number() -> u32 {
            $len
        }
    };

    // Recursive case: declare the next index, and then keep declaring the rest of
    // the indices.
    (
         @indices;
         $index:expr;
         $( #[$this_attr:meta] )*
         $this_name:ident;
         $(
             $( #[$rest_attr:meta] )*
             $rest_name:ident;
         )*
    ) => {
        $( #[$this_attr] )*
        pub const fn $this_name() -> Self {
            Self($index)
        }

        declare_indexes!(
            @indices;
            ($index + 1);
            $( $( #[$rest_attr] )* $rest_name; )*
        );
    }
}

foreach_builtin_function!(declare_indexes);