Struct wasmtime_environ::Module

pub struct Module {

    pub name: Option<String>,
    pub initializers: Vec<Initializer>,
    pub exports: IndexMap<String, EntityIndex>,
    pub start_func: Option<FuncIndex>,
    pub table_initialization: TableInitialization,
    pub memory_initialization: MemoryInitialization,
    pub passive_elements: Vec<Box<[FuncIndex]>>,
    pub passive_elements_map: BTreeMap<ElemIndex, usize>,
    pub passive_data_map: BTreeMap<DataIndex, Range<u32>>,
    pub types: PrimaryMap<TypeIndex, ModuleType>,
    pub num_imported_funcs: usize,
    pub num_imported_tables: usize,
    pub num_imported_memories: usize,
    pub num_imported_globals: usize,
    pub num_escaped_funcs: usize,
    pub functions: PrimaryMap<FuncIndex, FunctionType>,
    pub table_plans: PrimaryMap<TableIndex, TablePlan>,
    pub memory_plans: PrimaryMap<MemoryIndex, MemoryPlan>,
    pub globals: PrimaryMap<GlobalIndex, Global>,
}

A translated WebAssembly module, excluding the function bodies and memory initializers.

Fields

name: Option<String>

The name of this wasm module, often found in the wasm file.

initializers: Vec<Initializer>

All import records, in the order they are declared in the module.

exports: IndexMap<String, EntityIndex>

Exported entities.

start_func: Option<FuncIndex>

The module “start” function, if present.

table_initialization: TableInitialization

WebAssembly table initialization data, per table.

memory_initialization: MemoryInitialization

WebAssembly linear memory initializer.

passive_elements: Vec<Box<[FuncIndex]>>

WebAssembly passive elements.

passive_elements_map: BTreeMap<ElemIndex, usize>

The map from passive element index (element segment index space) to index in passive_elements.

passive_data_map: BTreeMap<DataIndex, Range<u32>>

The map from passive data index (data segment index space) to index in passive_data.

types: PrimaryMap<TypeIndex, ModuleType>

Types declared in the wasm module.

num_imported_funcs: usize

Number of imported or aliased functions in the module.

num_imported_tables: usize

Number of imported or aliased tables in the module.

num_imported_memories: usize

Number of imported or aliased memories in the module.

num_imported_globals: usize

Number of imported or aliased globals in the module.

num_escaped_funcs: usize

Number of functions that “escape” from this module may need to have a VMCallerCheckedAnyfunc constructed for them.

This is also the number of functions in the functions array below with an anyfunc index (and is the maximum anyfunc index).

functions: PrimaryMap<FuncIndex, FunctionType>

Types of functions, imported and local.

table_plans: PrimaryMap<TableIndex, TablePlan>

WebAssembly tables.

memory_plans: PrimaryMap<MemoryIndex, MemoryPlan>

WebAssembly linear memory plans.

globals: PrimaryMap<GlobalIndex, Global>

WebAssembly global variables.

Implementations

impl Module

pub fn new() -> Self

Allocates the module data structures.

pub fn func_index(&self, defined_func: DefinedFuncIndex) -> FuncIndex

Convert a DefinedFuncIndex into a FuncIndex.

pub fn defined_func_index(&self, func: FuncIndex) -> Option<DefinedFuncIndex>

Convert a FuncIndex into a DefinedFuncIndex. Returns None if the index is an imported function.

pub fn is_imported_function(&self, index: FuncIndex) -> bool

Test whether the given function index is for an imported function.

pub fn table_index(&self, defined_table: DefinedTableIndex) -> TableIndex

Convert a DefinedTableIndex into a TableIndex.

pub fn defined_table_index(&self, table: TableIndex) -> Option<DefinedTableIndex>

Convert a TableIndex into a DefinedTableIndex. Returns None if the index is an imported table.

Examples found in repository

src/module.rs (line 422)

    pub fn try_func_table_init(&mut self) {
        // This should be large enough to support very large Wasm
        // modules with huge funcref tables, but small enough to avoid
        // OOMs or DoS on truly sparse tables.
        const MAX_FUNC_TABLE_SIZE: u32 = 1024 * 1024;

        let segments = match &self.module.table_initialization {
            TableInitialization::Segments { segments } => segments,
            TableInitialization::FuncTable { .. } => {
                // Already done!
                return;
            }
        };

        // Build the table arrays per-table.
        let mut tables = PrimaryMap::with_capacity(self.module.table_plans.len());
        // Keep the "leftovers" for eager init.
        let mut leftovers = vec![];

        for segment in segments {
            // Skip imported tables: we can't provide a preconstructed
            // table for them, because their values depend on the
            // imported table overlaid with whatever segments we have.
            if self
                .module
                .defined_table_index(segment.table_index)
                .is_none()
            {
                leftovers.push(segment.clone());
                continue;
            }

            // If this is not a funcref table, then we can't support a
            // pre-computed table of function indices.
            if self.module.table_plans[segment.table_index].table.wasm_ty != WasmType::FuncRef {
                leftovers.push(segment.clone());
                continue;
            }

            // If the base of this segment is dynamic, then we can't
            // include it in the statically-built array of initial
            // contents.
            if segment.base.is_some() {
                leftovers.push(segment.clone());
                continue;
            }

            // Get the end of this segment. If out-of-bounds, or too
            // large for our dense table representation, then skip the
            // segment.
            let top = match segment.offset.checked_add(segment.elements.len() as u32) {
                Some(top) => top,
                None => {
                    leftovers.push(segment.clone());
                    continue;
                }
            };
            let table_size = self.module.table_plans[segment.table_index].table.minimum;
            if top > table_size || top > MAX_FUNC_TABLE_SIZE {
                leftovers.push(segment.clone());
                continue;
            }

            // We can now incorporate this segment into the initializers array.
            while tables.len() <= segment.table_index.index() {
                tables.push(vec![]);
            }
            let elements = &mut tables[segment.table_index];
            if elements.is_empty() {
                elements.resize(table_size as usize, FuncIndex::reserved_value());
            }

            let dst = &mut elements[(segment.offset as usize)..(top as usize)];
            dst.copy_from_slice(&segment.elements[..]);
        }

        self.module.table_initialization = TableInitialization::FuncTable {
            tables,
            segments: leftovers,
        };
    }

pub fn is_imported_table(&self, index: TableIndex) -> bool

Test whether the given table index is for an imported table.

pub fn memory_index(&self, defined_memory: DefinedMemoryIndex) -> MemoryIndex

Convert a DefinedMemoryIndex into a MemoryIndex.

pub fn defined_memory_index(
    &self,
    memory: MemoryIndex
) -> Option<DefinedMemoryIndex>

Convert a MemoryIndex into a DefinedMemoryIndex. Returns None if the index is an imported memory.

Examples found in repository

src/module.rs (line 250)

    pub fn try_static_init(&mut self, page_size: u64, max_image_size_always_allowed: u64) {
        // This method only attempts to transform a `Segmented` memory init
        // into a `Static` one, no other state.
        if !self.module.memory_initialization.is_segmented() {
            return;
        }

        // First a dry run of memory initialization is performed. This
        // collects information about the extent of memory initialized for each
        // memory as well as the size of all data segments being copied in.
        struct Memory {
            data_size: u64,
            min_addr: u64,
            max_addr: u64,
            // The `usize` here is a pointer into `self.data` which is the list
            // of data segments corresponding to what was found in the original
            // wasm module.
            segments: Vec<(usize, StaticMemoryInitializer)>,
        }
        let mut info = PrimaryMap::with_capacity(self.module.memory_plans.len());
        for _ in 0..self.module.memory_plans.len() {
            info.push(Memory {
                data_size: 0,
                min_addr: u64::MAX,
                max_addr: 0,
                segments: Vec::new(),
            });
        }
        let mut idx = 0;
        let ok = self.module.memory_initialization.init_memory(
            InitMemory::CompileTime(&self.module),
            &mut |memory, init| {
                // Currently `Static` only applies to locally-defined memories,
                // so if a data segment references an imported memory then
                // transitioning to a `Static` memory initializer is not
                // possible.
                if self.module.defined_memory_index(memory).is_none() {
                    return false;
                };
                let info = &mut info[memory];
                let data_len = u64::from(init.data.end - init.data.start);
                if data_len > 0 {
                    info.data_size += data_len;
                    info.min_addr = info.min_addr.min(init.offset);
                    info.max_addr = info.max_addr.max(init.offset + data_len);
                    info.segments.push((idx, init.clone()));
                }
                idx += 1;
                true
            },
        );
        if !ok {
            return;
        }

        // Validate that the memory information collected is indeed valid for
        // static memory initialization.
        for info in info.values().filter(|i| i.data_size > 0) {
            let image_size = info.max_addr - info.min_addr;

            // If the range of memory being initialized is less than twice the
            // total size of the data itself then it's assumed that static
            // initialization is ok. This means we'll at most double memory
            // consumption during the memory image creation process, which is
            // currently assumed to "probably be ok" but this will likely need
            // tweaks over time.
            if image_size < info.data_size.saturating_mul(2) {
                continue;
            }

            // If the memory initialization image is larger than the size of all
            // data, then we still allow memory initialization if the image will
            // be of a relatively modest size, such as 1MB here.
            if image_size < max_image_size_always_allowed {
                continue;
            }

            // At this point memory initialization is concluded to be too
            // expensive to do at compile time so it's entirely deferred to
            // happen at runtime.
            return;
        }

        // Here's where we've now committed to changing to static memory. The
        // memory initialization image is built here from the page data and then
        // it's converted to a single initializer.
        let data = mem::replace(&mut self.data, Vec::new());
        let mut map = PrimaryMap::with_capacity(info.len());
        let mut module_data_size = 0u32;
        for (memory, info) in info.iter() {
            // Create the in-memory `image` which is the initialized contents of
            // this linear memory.
            let extent = if info.segments.len() > 0 {
                (info.max_addr - info.min_addr) as usize
            } else {
                0
            };
            let mut image = Vec::with_capacity(extent);
            for (idx, init) in info.segments.iter() {
                let data = &data[*idx];
                assert_eq!(data.len(), init.data.len());
                let offset = usize::try_from(init.offset - info.min_addr).unwrap();
                if image.len() < offset {
                    image.resize(offset, 0u8);
                    image.extend_from_slice(data);
                } else {
                    image.splice(
                        offset..(offset + data.len()).min(image.len()),
                        data.iter().copied(),
                    );
                }
            }
            assert_eq!(image.len(), extent);
            assert_eq!(image.capacity(), extent);
            let mut offset = if info.segments.len() > 0 {
                info.min_addr
            } else {
                0
            };

            // Chop off trailing zeros from the image as memory is already
            // zero-initialized. Note that `i` is the position of a nonzero
            // entry here, so to not lose it we truncate to `i + 1`.
            if let Some(i) = image.iter().rposition(|i| *i != 0) {
                image.truncate(i + 1);
            }

            // Also chop off leading zeros, if any.
            if let Some(i) = image.iter().position(|i| *i != 0) {
                offset += i as u64;
                image.drain(..i);
            }
            let mut len = u64::try_from(image.len()).unwrap();

            // The goal is to enable mapping this image directly into memory, so
            // the offset into linear memory must be a multiple of the page
            // size. If that's not already the case then the image is padded at
            // the front and back with extra zeros as necessary
            if offset % page_size != 0 {
                let zero_padding = offset % page_size;
                self.data.push(vec![0; zero_padding as usize].into());
                offset -= zero_padding;
                len += zero_padding;
            }
            self.data.push(image.into());
            if len % page_size != 0 {
                let zero_padding = page_size - (len % page_size);
                self.data.push(vec![0; zero_padding as usize].into());
                len += zero_padding;
            }

            // Offset/length should now always be page-aligned.
            assert!(offset % page_size == 0);
            assert!(len % page_size == 0);

            // Create the `StaticMemoryInitializer` which describes this image,
            // only needed if the image is actually present and has a nonzero
            // length. The `offset` has been calculates above, originally
            // sourced from `info.min_addr`. The `data` field is the extent
            // within the final data segment we'll emit to an ELF image, which
            // is the concatenation of `self.data`, so here it's the size of
            // the section-so-far plus the current segment we're appending.
            let len = u32::try_from(len).unwrap();
            let init = if len > 0 {
                Some(StaticMemoryInitializer {
                    offset,
                    data: module_data_size..module_data_size + len,
                })
            } else {
                None
            };
            let idx = map.push(init);
            assert_eq!(idx, memory);
            module_data_size += len;
        }
        self.data_align = Some(page_size);
        self.module.memory_initialization = MemoryInitialization::Static { map };
    }

pub fn owned_memory_index(&self, memory: DefinedMemoryIndex) -> OwnedMemoryIndex

Convert a DefinedMemoryIndex into an OwnedMemoryIndex. Returns None if the index is an imported memory.

pub fn is_imported_memory(&self, index: MemoryIndex) -> bool

Test whether the given memory index is for an imported memory.

pub fn global_index(&self, defined_global: DefinedGlobalIndex) -> GlobalIndex

Convert a DefinedGlobalIndex into a GlobalIndex.

pub fn defined_global_index(
    &self,
    global: GlobalIndex
) -> Option<DefinedGlobalIndex>

Convert a GlobalIndex into a DefinedGlobalIndex. Returns None if the index is an imported global.

pub fn is_imported_global(&self, index: GlobalIndex) -> bool

Test whether the given global index is for an imported global.

pub fn imports(&self) -> impl ExactSizeIterator<Item = (&str, &str, EntityType)>

Returns an iterator of all the imports in this module, along with their module name, field name, and type that’s being imported.

pub fn type_of(&self, index: EntityIndex) -> EntityType

Returns the type of an item based on its index

Examples found in repository

src/module.rs (line 980)

    pub fn imports(&self) -> impl ExactSizeIterator<Item = (&str, &str, EntityType)> {
        self.initializers.iter().map(move |i| match i {
            Initializer::Import { name, field, index } => {
                (name.as_str(), field.as_str(), self.type_of(*index))
            }
        })
    }

pub fn push_function(&mut self, signature: SignatureIndex) -> FuncIndex

Appends a new function to this module with the given type information, used for functions that either don’t escape or aren’t certain whether they escape yet.

Examples found in repository

src/module_environ.rs (line 294)

    fn translate_payload(&mut self, payload: Payload<'data>) -> WasmResult<()> {
        match payload {
            Payload::Version {
                num,
                encoding,
                range,
            } => {
                self.validator.version(num, encoding, &range)?;
                match encoding {
                    Encoding::Module => {}
                    Encoding::Component => {
                        return Err(WasmError::Unsupported(format!("component model")));
                    }
                }
            }

            Payload::End(offset) => {
                self.result.types = Some(self.validator.end(offset)?);

                // With the `escaped_funcs` set of functions finished
                // we can calculate the set of signatures that are exported as
                // the set of exported functions' signatures.
                self.result.exported_signatures = self
                    .result
                    .module
                    .functions
                    .iter()
                    .filter_map(|(_, func)| {
                        if func.is_escaping() {
                            Some(func.signature)
                        } else {
                            None
                        }
                    })
                    .collect();
                self.result.exported_signatures.sort_unstable();
                self.result.exported_signatures.dedup();
            }

            Payload::TypeSection(types) => {
                self.validator.type_section(&types)?;
                let num = usize::try_from(types.get_count()).unwrap();
                self.result.module.types.reserve(num);
                self.types.reserve_wasm_signatures(num);

                for ty in types {
                    match ty? {
                        Type::Func(wasm_func_ty) => {
                            self.declare_type_func(wasm_func_ty.try_into()?)?;
                        }
                    }
                }
            }

            Payload::ImportSection(imports) => {
                self.validator.import_section(&imports)?;

                let cnt = usize::try_from(imports.get_count()).unwrap();
                self.result.module.initializers.reserve(cnt);

                for entry in imports {
                    let import = entry?;
                    let ty = match import.ty {
                        TypeRef::Func(index) => {
                            let index = TypeIndex::from_u32(index);
                            let sig_index = self.result.module.types[index].unwrap_function();
                            self.result.module.num_imported_funcs += 1;
                            self.result.debuginfo.wasm_file.imported_func_count += 1;
                            EntityType::Function(sig_index)
                        }
                        TypeRef::Memory(ty) => {
                            self.result.module.num_imported_memories += 1;
                            EntityType::Memory(ty.into())
                        }
                        TypeRef::Global(ty) => {
                            self.result.module.num_imported_globals += 1;
                            EntityType::Global(Global::new(ty, GlobalInit::Import)?)
                        }
                        TypeRef::Table(ty) => {
                            self.result.module.num_imported_tables += 1;
                            EntityType::Table(ty.try_into()?)
                        }

                        // doesn't get past validation
                        TypeRef::Tag(_) => unreachable!(),
                    };
                    self.declare_import(import.module, import.name, ty);
                }
            }

            Payload::FunctionSection(functions) => {
                self.validator.function_section(&functions)?;

                let cnt = usize::try_from(functions.get_count()).unwrap();
                self.result.module.functions.reserve_exact(cnt);

                for entry in functions {
                    let sigindex = entry?;
                    let ty = TypeIndex::from_u32(sigindex);
                    let sig_index = self.result.module.types[ty].unwrap_function();
                    self.result.module.push_function(sig_index);
                }
            }

            Payload::TableSection(tables) => {
                self.validator.table_section(&tables)?;
                let cnt = usize::try_from(tables.get_count()).unwrap();
                self.result.module.table_plans.reserve_exact(cnt);

                for entry in tables {
                    let table = entry?.try_into()?;
                    let plan = TablePlan::for_table(table, &self.tunables);
                    self.result.module.table_plans.push(plan);
                }
            }

            Payload::MemorySection(memories) => {
                self.validator.memory_section(&memories)?;

                let cnt = usize::try_from(memories.get_count()).unwrap();
                self.result.module.memory_plans.reserve_exact(cnt);

                for entry in memories {
                    let memory = entry?;
                    let plan = MemoryPlan::for_memory(memory.into(), &self.tunables);
                    self.result.module.memory_plans.push(plan);
                }
            }

            Payload::TagSection(tags) => {
                self.validator.tag_section(&tags)?;

                // This feature isn't enabled at this time, so we should
                // never get here.
                unreachable!();
            }

            Payload::GlobalSection(globals) => {
                self.validator.global_section(&globals)?;

                let cnt = usize::try_from(globals.get_count()).unwrap();
                self.result.module.globals.reserve_exact(cnt);

                for entry in globals {
                    let wasmparser::Global { ty, init_expr } = entry?;
                    let mut init_expr_reader = init_expr.get_binary_reader();
                    let initializer = match init_expr_reader.read_operator()? {
                        Operator::I32Const { value } => GlobalInit::I32Const(value),
                        Operator::I64Const { value } => GlobalInit::I64Const(value),
                        Operator::F32Const { value } => GlobalInit::F32Const(value.bits()),
                        Operator::F64Const { value } => GlobalInit::F64Const(value.bits()),
                        Operator::V128Const { value } => {
                            GlobalInit::V128Const(u128::from_le_bytes(*value.bytes()))
                        }
                        Operator::RefNull { ty: _ } => GlobalInit::RefNullConst,
                        Operator::RefFunc { function_index } => {
                            let index = FuncIndex::from_u32(function_index);
                            self.flag_func_escaped(index);
                            GlobalInit::RefFunc(index)
                        }
                        Operator::GlobalGet { global_index } => {
                            GlobalInit::GetGlobal(GlobalIndex::from_u32(global_index))
                        }
                        s => {
                            return Err(WasmError::Unsupported(format!(
                                "unsupported init expr in global section: {:?}",
                                s
                            )));
                        }
                    };
                    let ty = Global::new(ty, initializer)?;
                    self.result.module.globals.push(ty);
                }
            }

            Payload::ExportSection(exports) => {
                self.validator.export_section(&exports)?;

                let cnt = usize::try_from(exports.get_count()).unwrap();
                self.result.module.exports.reserve(cnt);

                for entry in exports {
                    let wasmparser::Export { name, kind, index } = entry?;
                    let entity = match kind {
                        ExternalKind::Func => {
                            let index = FuncIndex::from_u32(index);
                            self.flag_func_escaped(index);
                            EntityIndex::Function(index)
                        }
                        ExternalKind::Table => EntityIndex::Table(TableIndex::from_u32(index)),
                        ExternalKind::Memory => EntityIndex::Memory(MemoryIndex::from_u32(index)),
                        ExternalKind::Global => EntityIndex::Global(GlobalIndex::from_u32(index)),

                        // this never gets past validation
                        ExternalKind::Tag => unreachable!(),
                    };
                    self.result
                        .module
                        .exports
                        .insert(String::from(name), entity);
                }
            }

            Payload::StartSection { func, range } => {
                self.validator.start_section(func, &range)?;

                let func_index = FuncIndex::from_u32(func);
                self.flag_func_escaped(func_index);
                debug_assert!(self.result.module.start_func.is_none());
                self.result.module.start_func = Some(func_index);
            }

            Payload::ElementSection(elements) => {
                self.validator.element_section(&elements)?;

                for (index, entry) in elements.into_iter().enumerate() {
                    let wasmparser::Element {
                        kind,
                        items,
                        ty: _,
                        range: _,
                    } = entry?;

                    // Build up a list of `FuncIndex` corresponding to all the
                    // entries listed in this segment. Note that it's not
                    // possible to create anything other than a `ref.null
                    // extern` for externref segments, so those just get
                    // translated to the reserved value of `FuncIndex`.
                    let items_reader = items.get_items_reader()?;
                    let mut elements =
                        Vec::with_capacity(usize::try_from(items_reader.get_count()).unwrap());
                    for item in items_reader {
                        let func = match item? {
                            ElementItem::Func(f) => Some(f),
                            ElementItem::Expr(init) => {
                                match init.get_binary_reader().read_operator()? {
                                    Operator::RefNull { .. } => None,
                                    Operator::RefFunc { function_index } => Some(function_index),
                                    s => {
                                        return Err(WasmError::Unsupported(format!(
                                            "unsupported init expr in element section: {:?}",
                                            s
                                        )));
                                    }
                                }
                            }
                        };
                        elements.push(match func {
                            Some(f) => {
                                let f = FuncIndex::from_u32(f);
                                self.flag_func_escaped(f);
                                f
                            }
                            None => FuncIndex::reserved_value(),
                        });
                    }

                    match kind {
                        ElementKind::Active {
                            table_index,
                            offset_expr,
                        } => {
                            let table_index = TableIndex::from_u32(table_index);
                            let mut offset_expr_reader = offset_expr.get_binary_reader();
                            let (base, offset) = match offset_expr_reader.read_operator()? {
                                Operator::I32Const { value } => (None, value as u32),
                                Operator::GlobalGet { global_index } => {
                                    (Some(GlobalIndex::from_u32(global_index)), 0)
                                }
                                ref s => {
                                    return Err(WasmError::Unsupported(format!(
                                        "unsupported init expr in element section: {:?}",
                                        s
                                    )));
                                }
                            };

                            let table_segments = match &mut self.result.module.table_initialization
                            {
                                TableInitialization::Segments { segments } => segments,
                                TableInitialization::FuncTable { .. } => unreachable!(),
                            };
                            table_segments.push(TableInitializer {
                                table_index,
                                base,
                                offset,
                                elements: elements.into(),
                            });
                        }

                        ElementKind::Passive => {
                            let elem_index = ElemIndex::from_u32(index as u32);
                            let index = self.result.module.passive_elements.len();
                            self.result.module.passive_elements.push(elements.into());
                            self.result
                                .module
                                .passive_elements_map
                                .insert(elem_index, index);
                        }

                        ElementKind::Declared => {}
                    }
                }
            }

            Payload::CodeSectionStart { count, range, .. } => {
                self.validator.code_section_start(count, &range)?;
                let cnt = usize::try_from(count).unwrap();
                self.result.function_body_inputs.reserve_exact(cnt);
                self.result.debuginfo.wasm_file.code_section_offset = range.start as u64;
            }

            Payload::CodeSectionEntry(mut body) => {
                let validator = self.validator.code_section_entry(&body)?;
                let func_index =
                    self.result.code_index + self.result.module.num_imported_funcs as u32;
                let func_index = FuncIndex::from_u32(func_index);

                if self.tunables.generate_native_debuginfo {
                    let sig_index = self.result.module.functions[func_index].signature;
                    let sig = &self.types[sig_index];
                    let mut locals = Vec::new();
                    for pair in body.get_locals_reader()? {
                        locals.push(pair?);
                    }
                    self.result
                        .debuginfo
                        .wasm_file
                        .funcs
                        .push(FunctionMetadata {
                            locals: locals.into_boxed_slice(),
                            params: sig.params().iter().cloned().map(|i| i.into()).collect(),
                        });
                }
                body.allow_memarg64(self.validator.features().memory64);
                self.result
                    .function_body_inputs
                    .push(FunctionBodyData { validator, body });
                self.result.code_index += 1;
            }

            Payload::DataSection(data) => {
                self.validator.data_section(&data)?;

                let initializers = match &mut self.result.module.memory_initialization {
                    MemoryInitialization::Segmented(i) => i,
                    _ => unreachable!(),
                };

                let cnt = usize::try_from(data.get_count()).unwrap();
                initializers.reserve_exact(cnt);
                self.result.data.reserve_exact(cnt);

                for (index, entry) in data.into_iter().enumerate() {
                    let wasmparser::Data {
                        kind,
                        data,
                        range: _,
                    } = entry?;
                    let mk_range = |total: &mut u32| -> Result<_, WasmError> {
                        let range = u32::try_from(data.len())
                            .ok()
                            .and_then(|size| {
                                let start = *total;
                                let end = start.checked_add(size)?;
                                Some(start..end)
                            })
                            .ok_or_else(|| {
                                WasmError::Unsupported(format!(
                                    "more than 4 gigabytes of data in wasm module",
                                ))
                            })?;
                        *total += range.end - range.start;
                        Ok(range)
                    };
                    match kind {
                        DataKind::Active {
                            memory_index,
                            offset_expr,
                        } => {
                            let range = mk_range(&mut self.result.total_data)?;
                            let memory_index = MemoryIndex::from_u32(memory_index);
                            let mut offset_expr_reader = offset_expr.get_binary_reader();
                            let (base, offset) = match offset_expr_reader.read_operator()? {
                                Operator::I32Const { value } => (None, value as u64),
                                Operator::I64Const { value } => (None, value as u64),
                                Operator::GlobalGet { global_index } => {
                                    (Some(GlobalIndex::from_u32(global_index)), 0)
                                }
                                s => {
                                    return Err(WasmError::Unsupported(format!(
                                        "unsupported init expr in data section: {:?}",
                                        s
                                    )));
                                }
                            };

                            initializers.push(MemoryInitializer {
                                memory_index,
                                base,
                                offset,
                                data: range,
                            });
                            self.result.data.push(data.into());
                        }
                        DataKind::Passive => {
                            let data_index = DataIndex::from_u32(index as u32);
                            let range = mk_range(&mut self.result.total_passive_data)?;
                            self.result.passive_data.push(data);
                            self.result
                                .module
                                .passive_data_map
                                .insert(data_index, range);
                        }
                    }
                }
            }

            Payload::DataCountSection { count, range } => {
                self.validator.data_count_section(count, &range)?;

                // Note: the count passed in here is the *total* segment count
                // There is no way to reserve for just the passive segments as
                // they are discovered when iterating the data section entries
                // Given that the total segment count might be much larger than
                // the passive count, do not reserve anything here.
            }

            Payload::CustomSection(s) if s.name() == "name" => {
                let result = NameSectionReader::new(s.data(), s.data_offset())
                    .map_err(|e| e.into())
                    .and_then(|s| self.name_section(s));
                if let Err(e) = result {
                    log::warn!("failed to parse name section {:?}", e);
                }
            }

            Payload::CustomSection(s)
                if s.name() == "webidl-bindings" || s.name() == "wasm-interface-types" =>
            {
                return Err(WasmError::Unsupported(
                    "\
Support for interface types has temporarily been removed from `wasmtime`.

For more information about this temporary change you can read on the issue online:

    https://github.com/bytecodealliance/wasmtime/issues/1271

and for re-adding support for interface types you can see this issue:

    https://github.com/bytecodealliance/wasmtime/issues/677
"
                    .to_string(),
                ))
            }

            Payload::CustomSection(s) => {
                self.register_dwarf_section(&s);
            }

            // It's expected that validation will probably reject other
            // payloads such as `UnknownSection` or those related to the
            // component model. If, however, something gets past validation then
            // that's a bug in Wasmtime as we forgot to implement something.
            other => {
                self.validator.payload(&other)?;
                panic!("unimplemented section in wasm file {:?}", other);
            }
        }
        Ok(())
    }

    fn register_dwarf_section(&mut self, section: &CustomSectionReader<'data>) {
        let name = section.name();
        if !name.starts_with(".debug_") {
            return;
        }
        if !self.tunables.generate_native_debuginfo && !self.tunables.parse_wasm_debuginfo {
            self.result.has_unparsed_debuginfo = true;
            return;
        }
        let info = &mut self.result.debuginfo;
        let dwarf = &mut info.dwarf;
        let endian = gimli::LittleEndian;
        let data = section.data();
        let slice = gimli::EndianSlice::new(data, endian);

        match name {
            // `gimli::Dwarf` fields.
            ".debug_abbrev" => dwarf.debug_abbrev = gimli::DebugAbbrev::new(data, endian),
            ".debug_addr" => dwarf.debug_addr = gimli::DebugAddr::from(slice),
            ".debug_info" => dwarf.debug_info = gimli::DebugInfo::new(data, endian),
            ".debug_line" => dwarf.debug_line = gimli::DebugLine::new(data, endian),
            ".debug_line_str" => dwarf.debug_line_str = gimli::DebugLineStr::from(slice),
            ".debug_str" => dwarf.debug_str = gimli::DebugStr::new(data, endian),
            ".debug_str_offsets" => dwarf.debug_str_offsets = gimli::DebugStrOffsets::from(slice),
            ".debug_str_sup" => {
                let mut dwarf_sup: Dwarf<'data> = Default::default();
                dwarf_sup.debug_str = gimli::DebugStr::from(slice);
                dwarf.sup = Some(Arc::new(dwarf_sup));
            }
            ".debug_types" => dwarf.debug_types = gimli::DebugTypes::from(slice),

            // Additional fields.
            ".debug_loc" => info.debug_loc = gimli::DebugLoc::from(slice),
            ".debug_loclists" => info.debug_loclists = gimli::DebugLocLists::from(slice),
            ".debug_ranges" => info.debug_ranges = gimli::DebugRanges::new(data, endian),
            ".debug_rnglists" => info.debug_rnglists = gimli::DebugRngLists::new(data, endian),

            // We don't use these at the moment.
            ".debug_aranges" | ".debug_pubnames" | ".debug_pubtypes" => return,

            other => {
                log::warn!("unknown debug section `{}`", other);
                return;
            }
        }

        dwarf.ranges = gimli::RangeLists::new(info.debug_ranges, info.debug_rnglists);
        dwarf.locations = gimli::LocationLists::new(info.debug_loc, info.debug_loclists);
    }

    /// Declares a new import with the `module` and `field` names, importing the
    /// `ty` specified.
    ///
    /// Note that this method is somewhat tricky due to the implementation of
    /// the module linking proposal. In the module linking proposal two-level
    /// imports are recast as single-level imports of instances. That recasting
    /// happens here by recording an import of an instance for the first time
    /// we see a two-level import.
    ///
    /// When the module linking proposal is disabled, however, disregard this
    /// logic and instead work directly with two-level imports since no
    /// instances are defined.
    fn declare_import(&mut self, module: &'data str, field: &'data str, ty: EntityType) {
        let index = self.push_type(ty);
        self.result.module.initializers.push(Initializer::Import {
            name: module.to_owned(),
            field: field.to_owned(),
            index,
        });
    }

    fn push_type(&mut self, ty: EntityType) -> EntityIndex {
        match ty {
            EntityType::Function(ty) => EntityIndex::Function(self.result.module.push_function(ty)),
            EntityType::Table(ty) => {
                let plan = TablePlan::for_table(ty, &self.tunables);
                EntityIndex::Table(self.result.module.table_plans.push(plan))
            }
            EntityType::Memory(ty) => {
                let plan = MemoryPlan::for_memory(ty, &self.tunables);
                EntityIndex::Memory(self.result.module.memory_plans.push(plan))
            }
            EntityType::Global(ty) => EntityIndex::Global(self.result.module.globals.push(ty)),
            EntityType::Tag(_) => unimplemented!(),
        }
    }

pub fn push_escaped_function(
    &mut self,
    signature: SignatureIndex,
    anyfunc: AnyfuncIndex
) -> FuncIndex

Appends a new function to this module with the given type information.

Trait Implementations

impl Debug for Module

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Module

fn default() -> Module

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Module

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
    __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Module

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>where
    __S: Serializer,

Serialize this value into the given Serde serializer.