      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
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255
    256
    257
    258
    259
    260
    261
    262
    263
    264
    265
    266
    267
    268
    269
    270
    271
    272
    273
    274
    275
    276
    277
    278
    279
    280
    281
    282
    283
    284
    285
    286
    287
    288
    289
    290
    291
    292
    293
    294
    295
    296
    297
    298
    299
    300
    301
    302
    303
    304
    305
    306
    307
    308
    309
    310
    311

    use alloc::{collections::BTreeMap, string::String};

    use func::FuncRef;
    use global::GlobalRef;
    use memory::MemoryRef;
    use module::ModuleRef;
    use table::TableRef;
    use types::{GlobalDescriptor, MemoryDescriptor, TableDescriptor};
    use {Error, Signature};

    /// Resolver of a module's dependencies.
    ///
    /// A module have dependencies in a form of a list of imports (i.e.
    /// tuple of a (`module_name`, `field_name`, `descriptor`)).
    ///
    /// The job of implementations of this trait is to provide on each
    /// import a corresponding concrete reference.
    ///
    /// For simple use-cases you can use [`ImportsBuilder`].
    ///
    /// [`ImportsBuilder`]: struct.ImportsBuilder.html
    pub trait ImportResolver {
        /// Resolve a function.
        ///
        /// Returned function should match given `signature`, i.e. all parameter types and return value should have exact match.
        /// Otherwise, link-time error will occur.
        fn resolve_func(
            &self,
            _module_name: &str,
            field_name: &str,
            _signature: &Signature,
        ) -> Result<FuncRef, Error>;

        /// Resolve a global variable.
        ///
        /// Returned global should match given `descriptor`, i.e. type and mutability
        /// should match. Otherwise, link-time error will occur.
        fn resolve_global(
            &self,
            module_name: &str,
            field_name: &str,
            descriptor: &GlobalDescriptor,
        ) -> Result<GlobalRef, Error>;

        /// Resolve a memory.
        ///
        /// Returned memory should match requested memory (described by the `descriptor`),
        /// i.e. initial size of a returned memory should be equal or larger than requested memory.
        /// Furthermore, if requested memory have maximum size, returned memory either should have
        /// equal or larger maximum size or have no maximum size at all.
        /// If returned memory doesn't match the requested then link-time error will occur.
        fn resolve_memory(
            &self,
            module_name: &str,
            field_name: &str,
            descriptor: &MemoryDescriptor,
        ) -> Result<MemoryRef, Error>;

        /// Resolve a table.
        ///
        /// Returned table should match requested table (described by the `descriptor`),
        /// i.e. initial size of a returned table should be equal or larger than requested table.
        /// Furthermore, if requested memory have maximum size, returned memory either should have
        /// equal or larger maximum size or have no maximum size at all.
        /// If returned table doesn't match the requested then link-time error will occur.
        fn resolve_table(
            &self,
            module_name: &str,
            field_name: &str,
            descriptor: &TableDescriptor,
        ) -> Result<TableRef, Error>;
    }

    /// Convenience builder of [`ImportResolver`].
    ///
    /// With help of this builder, you can easily create [`ImportResolver`], just by
    /// adding needed [resolvers][`ModuleImportResolver`] by names.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use wasmi::{ModuleInstance, ImportsBuilder};
    /// #
    /// # struct EnvModuleResolver;
    /// # impl ::wasmi::ModuleImportResolver for EnvModuleResolver { }
    /// # fn func() -> Result<(), ::wasmi::Error> {
    /// # let module = wasmi::Module::from_buffer(&[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00]).unwrap();
    /// # let other_instance = ModuleInstance::new(&module, &ImportsBuilder::default())?.assert_no_start();
    ///
    /// let imports = ImportsBuilder::new()
    ///     .with_resolver("env", &EnvModuleResolver)
    ///     // Note, that ModuleInstance can be a resolver too.
    ///     .with_resolver("other_instance", &other_instance);
    /// let instance = ModuleInstance::new(&module, &imports)?.assert_no_start();
    ///
    /// # Ok(())
    /// # }
    /// ```
    ///
    /// [`ImportResolver`]: trait.ImportResolver.html
    /// [`ModuleImportResolver`]: trait.ModuleImportResolver.html
    pub struct ImportsBuilder<'a> {
        modules: BTreeMap<String, &'a dyn ModuleImportResolver>,
    }

    impl<'a> Default for ImportsBuilder<'a> {
        fn default() -> Self {
            Self::new()
        }
    }

    impl<'a> ImportsBuilder<'a> {
        /// Create an empty `ImportsBuilder`.
        pub fn new() -> ImportsBuilder<'a> {
            ImportsBuilder {
                modules: BTreeMap::new(),
            }
        }

        /// Register an resolver by a name.
        pub fn with_resolver<N: Into<String>>(
            mut self,
            name: N,
            resolver: &'a dyn ModuleImportResolver,
        ) -> Self {
            self.modules.insert(name.into(), resolver);
            self
        }

        /// Register an resolver by a name.
        ///
        /// Mutable borrowed version.
        pub fn push_resolver<N: Into<String>>(
            &mut self,
            name: N,
            resolver: &'a dyn ModuleImportResolver,
        ) {
            self.modules.insert(name.into(), resolver);
        }

        fn resolver(&self, name: &str) -> Option<&dyn ModuleImportResolver> {
            self.modules.get(name).cloned()
        }
    }

    impl<'a> ImportResolver for ImportsBuilder<'a> {
        fn resolve_func(
            &self,
            module_name: &str,
            field_name: &str,
            signature: &Signature,
        ) -> Result<FuncRef, Error> {
            self.resolver(module_name)
                .ok_or_else(|| Error::Instantiation(format!("Module {} not found", module_name)))?
                .resolve_func(field_name, signature)
        }

        fn resolve_global(
            &self,
            module_name: &str,
            field_name: &str,
            global_type: &GlobalDescriptor,
        ) -> Result<GlobalRef, Error> {
            self.resolver(module_name)
                .ok_or_else(|| Error::Instantiation(format!("Module {} not found", module_name)))?
                .resolve_global(field_name, global_type)
        }

        fn resolve_memory(
            &self,
            module_name: &str,
            field_name: &str,
            memory_type: &MemoryDescriptor,
        ) -> Result<MemoryRef, Error> {
            self.resolver(module_name)
                .ok_or_else(|| Error::Instantiation(format!("Module {} not found", module_name)))?
                .resolve_memory(field_name, memory_type)
        }

        fn resolve_table(
            &self,
            module_name: &str,
            field_name: &str,
            table_type: &TableDescriptor,
        ) -> Result<TableRef, Error> {
            self.resolver(module_name)
                .ok_or_else(|| Error::Instantiation(format!("Module {} not found", module_name)))?
                .resolve_table(field_name, table_type)
        }
    }

    /// Version of [`ImportResolver`] specialized for a single module.
    ///
    /// [`ImportResolver`]: trait.ImportResolver.html
    pub trait ModuleImportResolver {
        /// Resolve a function.
        ///
        /// See [`ImportResolver::resolve_func`] for details.
        ///
        /// [`ImportResolver::resolve_func`]: trait.ImportResolver.html#tymethod.resolve_func
        fn resolve_func(&self, field_name: &str, _signature: &Signature) -> Result<FuncRef, Error> {
            Err(Error::Instantiation(format!(
                "Export {} not found",
                field_name
            )))
        }

        /// Resolve a global variable.
        ///
        /// See [`ImportResolver::resolve_global`] for details.
        ///
        /// [`ImportResolver::resolve_global`]: trait.ImportResolver.html#tymethod.resolve_global
        fn resolve_global(
            &self,
            field_name: &str,
            _global_type: &GlobalDescriptor,
        ) -> Result<GlobalRef, Error> {
            Err(Error::Instantiation(format!(
                "Export {} not found",
                field_name
            )))
        }

        /// Resolve a memory.
        ///
        /// See [`ImportResolver::resolve_memory`] for details.
        ///
        /// [`ImportResolver::resolve_memory`]: trait.ImportResolver.html#tymethod.resolve_memory
        fn resolve_memory(
            &self,
            field_name: &str,
            _memory_type: &MemoryDescriptor,
        ) -> Result<MemoryRef, Error> {
            Err(Error::Instantiation(format!(
                "Export {} not found",
                field_name
            )))
        }

        /// Resolve a table.
        ///
        /// See [`ImportResolver::resolve_table`] for details.
        ///
        /// [`ImportResolver::resolve_table`]: trait.ImportResolver.html#tymethod.resolve_table
        fn resolve_table(
            &self,
            field_name: &str,
            _table_type: &TableDescriptor,
        ) -> Result<TableRef, Error> {
            Err(Error::Instantiation(format!(
                "Export {} not found",
                field_name
            )))
        }
    }

    impl ModuleImportResolver for ModuleRef {
        fn resolve_func(&self, field_name: &str, _signature: &Signature) -> Result<FuncRef, Error> {
            Ok(self
                .export_by_name(field_name)
                .ok_or_else(|| Error::Instantiation(format!("Export {} not found", field_name)))?
                .as_func()
                .cloned()
                .ok_or_else(|| {
                    Error::Instantiation(format!("Export {} is not a function", field_name))
                })?)
        }

        fn resolve_global(
            &self,
            field_name: &str,
            _global_type: &GlobalDescriptor,
        ) -> Result<GlobalRef, Error> {
            Ok(self
                .export_by_name(field_name)
                .ok_or_else(|| Error::Instantiation(format!("Export {} not found", field_name)))?
                .as_global()
                .cloned()
                .ok_or_else(|| {
                    Error::Instantiation(format!("Export {} is not a global", field_name))
                })?)
        }

        fn resolve_memory(
            &self,
            field_name: &str,
            _memory_type: &MemoryDescriptor,
        ) -> Result<MemoryRef, Error> {
            Ok(self
                .export_by_name(field_name)
                .ok_or_else(|| Error::Instantiation(format!("Export {} not found", field_name)))?
                .as_memory()
                .cloned()
                .ok_or_else(|| {
                    Error::Instantiation(format!("Export {} is not a memory", field_name))
                })?)
        }

        fn resolve_table(
            &self,
            field_name: &str,
            _table_type: &TableDescriptor,
        ) -> Result<TableRef, Error> {
            Ok(self
                .export_by_name(field_name)
                .ok_or_else(|| Error::Instantiation(format!("Export {} not found", field_name)))?
                .as_table()
                .cloned()
                .ok_or_else(|| Error::Instantiation(format!("Export {} is not a table", field_name)))?)
        }
    }

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g., `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g., `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g., `str,u8` or `String,struct:Vec,test`)