Crate wasmparser

A simple event-driven library for parsing WebAssembly binary files (or streams).

The parser library reports events as they happen and only stores parsing information for a brief period of time, making it very fast and memory-efficient. The event-driven model, however, has some drawbacks. If you need random access to the entire WebAssembly data-structure, this is not the right library for you. You could however, build such a data-structure using this library.

To get started, create a Parser using Parser::new and then follow the examples documented for Parser::parse or Parser::parse_all.

Modules

• collectionsvalidate
  Type definitions for maps and sets used by the wasmparser crate.
• namesvalidate
  Definitions of name-related helpers and newtypes, primarily for the component model.
• typesvalidate
  Types relating to type information provided by validation.

Macros

• for_each_operator
  A helper macro to conveniently iterate over all opcodes recognized by this crate. This can be used to work with either the Operator enumeration or the VisitOperator trait if your use case uniformly handles all operators the same way.

Structs

• ArrayType
  Represents a type of an array in a WebAssembly module.
• BinaryReader
  A binary reader of the WebAssembly structures and types.
• BinaryReaderError
  A binary reader for WebAssembly modules.
• BrTable
  A br_table entries representation.
• BranchHint
  A hint for a single branch.
• BranchHintFunction
  Branch hints for a single function.
• Comdat
  Represents COMDAT data in the linking custom section.
• ComdatSymbol
  Represents a symbol that is part of a comdat.
• ComponentExport
  Represents an export in a WebAssembly component.
• ComponentExportName
  Represents the name of a component export.
• ComponentFuncType
  Represents a type of a function in a WebAssembly component.
• ComponentImport
  Represents an import in a WebAssembly component
• ComponentImportName
  Represents the name of a component import.
• ComponentInstantiationArg
  Represents an argument to instantiating a WebAssembly component.
• ComponentStartFunction
  Represents the start function in a WebAssembly component.
• CompositeType
  Represents a composite type in a WebAssembly module.
• ConstExpr
  Represents an initialization expression.
• ContType
  Represents a type of a continuation in a WebAssembly module.
• CoreDumpInstance
  A single instance from a coredump instances section
• CoreDumpInstancesSection
  A custom section representing the instances involved in a given coredump
• CoreDumpModulesSection
  The data portion of a “coremodules” custom section. This contains a vec of module names that will be referenced by index by other coredump sections.
• CoreDumpSection
  The data portion of a custom section representing a core dump. Per the tool-conventions repo, this section just specifies the executable name that the core dump came from while the rest of the core dump information is contained in a corestack custom section
• CoreDumpStackFrame
  A single stack frame from a core dump
• CoreDumpStackSection
  The data portion of a custom section representing a core dump stack. The structure of this follows the coredump spec in the tool-conventions repo
• CustomSectionReader
  A reader for custom sections of a WebAssembly module.
• Data
  Represents a data segment in a core WebAssembly module.
• DefinedDataSymbol
  Represents the metadata about a data symbol defined in the wasm file.
• Element
  Represents a core WebAssembly element segment.
• Export
  Represents an export in a WebAssembly module.
• ExportInfo
• FieldType
  Represents a field type of an array or a struct.
• Framevalidate
  A Wasm control flow block on the control flow stack during Wasm validation.
• FuncToValidatevalidate
  Resources necessary to perform validation of a function.
• FuncType
  Represents a type of a function in a WebAssembly module.
• FuncValidatorvalidate
  Validation context for a WebAssembly function.
• FuncValidatorAllocationsvalidate
  External handle to the internal allocations used during function validation.
• FunctionBody
  Represents a WebAssembly function body.
• Global
  Represents a core WebAssembly global.
• GlobalType
  Represents a global’s type.
• Ieee32
  An IEEE binary32 immediate floating point value, represented as a u32 containing the bit pattern.
• Ieee64
  An IEEE binary64 immediate floating point value, represented as a u64 containing the bit pattern.
• Import
  Represents an import in a WebAssembly module.
• ImportInfo
• IndirectNaming
  Represents an indirect name in the names custom section.
• InitFunc
  Represents an init function in the linking custom section.
• InstantiationArg
  Represents an argument to instantiating a WebAssembly module.
• LinkingSectionReader
  A reader for the linking custom section of a WebAssembly module.
• LocalsIterator
  An iterator over locals in a function body.
• LocalsReader
  A reader for a function body’s locals.
• MemArg
  Represents a memory immediate in a WebAssembly memory instruction.
• MemInfo
  Represents a WASM_DYLINK_MEM_INFO field
• MemoryType
  Represents a memory’s type.
• Naming
  Represents a name for an index from the names section.
• OperatorsIterator
  An iterator over a function’s operators.
• OperatorsIteratorWithOffsets
  An iterator over a function’s operators with offsets.
• OperatorsReader
  A reader for a core WebAssembly function’s operators.
• PackedIndex
  A packed representation of a type index.
• Parser
  An incremental parser of a binary WebAssembly module or component.
• ProducersField
  A field from the producers custom section.
• ProducersFieldValue
  Represents a field value in the producers custom section.
• RecGroup
  Represents a recursive type group in a WebAssembly module.
• RefType
  A reference type.
• RelocSectionReader
  Reader for reloc.* sections as defined by https://github.com/WebAssembly/tool-conventions/blob/main/Linking.md#relocation-sections.
• RelocationEntry
  Single relocation entry within a reloc.* section, as defined at https://github.com/WebAssembly/tool-conventions/blob/main/Linking.md#relocation-sections.
• ResumeTable
  A representation of dispatch tables on resume and resume_throw instructions.
• SectionLimited
  A generic structure for reading a section of a WebAssembly binary which has a limited number of items within it.
• SectionLimitedIntoIter
  A consuming iterator of a SectionLimited.
• SectionLimitedIntoIterWithOffsets
  An iterator over a limited section iterator.
• Segment
  Represents extra metadata about the data segments.
• SegmentFlags
  Flags for WebAssembly segments.
• StructType
  Represents a type of a struct in a WebAssembly module.
• SubType
  Represents a subtype of possible other types in a WebAssembly module.
• Subsections
  Iterator/reader over the contents of a section which is composed of subsections.
• SymbolFlags
  Flags for WebAssembly symbols.
• Table
  Type information about a table defined in the table section of a WebAssembly module.
• TableType
  Represents a table’s type.
• TagType
  A tag’s type.
• TryTable
  A try_table entries representation.
• V128
  Represents a 128-bit vector value.
• Validatorvalidate
  Validator for a WebAssembly binary module or component.
• ValidatorIdvalidate
  A unique identifier for a particular Validator.
• ValidatorResourcesvalidate
  The implementation of WasmModuleResources used by Validator.
• VariantCase
  Represents a case in a variant type.
• WasmFeatures
  Flags for features that are enabled for validation.
• WasmFeaturesInflatedfeatures
  Inflated version of WasmFeatures that allows for exhaustive matching on fields.

Enums

• AbstractHeapType
  An abstract heap type.
• BlockType
  Represents a block type.
• CanonicalFunction
  Represents a canonical function in a WebAssembly component.
• CanonicalOption
  Represents options for component functions.
• Catch
  Catch clauses that can be specified in TryTable.
• Chunk
  A successful return payload from Parser::parse.
• ComdatSymbolKind
  Represents a symbol kind.
• ComponentAlias
  Represents an alias in a WebAssembly component.
• ComponentDefinedType
  Represents a defined type in a WebAssembly component.
• ComponentExternalKind
  Represents the kind of an external items of a WebAssembly component.
• ComponentFuncResult
  Represents the result type of a component function.
• ComponentInstance
  Represents an instance in a WebAssembly component.
• ComponentName
  Represents a name read from the names custom section.
• ComponentOuterAliasKind
  Represents the kind of an outer alias in a WebAssembly component.
• ComponentType
  Represents a type in a WebAssembly component.
• ComponentTypeDeclaration
  Represents part of a component type declaration in a WebAssembly component.
• ComponentTypeRef
  Represents a reference to a component type.
• ComponentValType
  Represents a value type in a WebAssembly component.
• CompositeInnerType
  A CompositeType can contain one of these types.
• CoreDumpValue
  Local and stack values are encoded using one byte for the type (similar to Wasm’s Number Types) followed by bytes representing the actual value See the tool-conventions repo for more details.
• CoreType
  Represents a core type in a WebAssembly component.
• DataKind
  The kind of data segment.
• Dylink0Subsection
  Possible subsections of the dylink.0 custom section.
• ElementItems
  Represents the items of an element segment.
• ElementKind
  The kind of element segment.
• Encoding
  The supported encoding formats for the parser.
• ExternalKind
  External types as defined here.
• FrameKind
  The kind of a control flow [Frame].
• Handle
  Handle clauses that can be specified in ResumeTable.
• HeapType
  A heap type.
• Instance
  Represents an instance of a WebAssembly module.
• InstanceTypeDeclaration
  Represents an instance type declaration in a WebAssembly component.
• InstantiationArgKind
  Represents the kind of an instantiation argument for a core instance.
• KnownCustom
  Return value of CustomSectionReader::as_known.
• Linking
  Represents a subsection read from the linking custom section.
• ModuleTypeDeclaration
  Represents a module type declaration in a WebAssembly component.
• Name
  Represents a name read from the names custom section.
• Operator
  Instructions as defined here.
• Ordering
  Represents the memory ordering for atomic instructions.
• OuterAliasKind
  Represents the kind of an outer core alias in a WebAssembly component.
• Payload
  Values that can be parsed from a WebAssembly module or component.
• PrimitiveValType
  Represents a primitive value type.
• RelocAddendKind
  Indicates the kind of addend that applies to a relocation entry.
• RelocationType
  Relocation entry type. Each entry type corresponds to one of the R_WASM_* constants defined at https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/BinaryFormat/WasmRelocs.def and https://github.com/WebAssembly/tool-conventions/blob/main/Linking.md#relocation-sections.
• StorageType
  Represents storage types introduced in the GC spec for array and struct fields.
• SymbolInfo
  Represents extra information about symbols in the linking custom section.
• TableInit
  Different modes of initializing a table.
• TagKind
  Represents a tag kind.
• TypeBounds
  Represents the type bounds for imports and exports.
• TypeRef
  Represents a reference to a type definition in a WebAssembly module.
• UnpackedIndex
  The uncompressed form of a PackedIndex.
• ValType
  Represents the types of values in a WebAssembly module.
• ValidPayloadvalidate
  Possible return values from Validator::payload.

Traits

• FromReader
  A trait implemented for items that can be decoded directly from a BinaryReader, or that which can be parsed from the WebAssembly binary format.
• ModuleArity
  To compute the arity (param and result counts) of “variable-arity” operators, the operator_arity macro needs information about the module’s types and the current control stack. The ModuleArity trait exposes this information.
• Subsection
  A trait implemented for subsections of another outer section.
• VisitOperator
  Trait implemented by types that can visit all Operator variants.
• WasmModuleResourcesvalidate
  Types that qualify as Wasm validation database.

Functions

• validatevalidate
  Test whether the given buffer contains a valid WebAssembly module or component, analogous to WebAssembly.validate in the JS API.

Type Aliases

• BranchHintSectionReader
  A reader for the metadata.code.branch_hint custom section.
• CodeSectionReader
  A reader for the code section of a WebAssembly module.
• ComdatMap
  Represents a reader for COMDAT data from the linking custom section.
• ComponentAliasSectionReader
  Section reader for the component alias section
• ComponentCanonicalSectionReader
  A reader for the canonical section of a WebAssembly component.
• ComponentExportSectionReader
  A reader for the export section of a WebAssembly component.
• ComponentImportSectionReader
  A reader for the import section of a WebAssembly component.
• ComponentInstanceSectionReader
  A reader for the component instance section of a WebAssembly component.
• ComponentNameSectionReader
  Type used to iterate and parse the contents of the component-name custom section in compnents, similar to the name section of core modules.
• ComponentTypeSectionReader
  A reader for the type section of a WebAssembly component.
• CoreTypeSectionReader
  A reader for the core type section of a WebAssembly component.
• DataSectionReader
  A reader for the data section of a WebAssembly module.
• Dylink0SectionReader
  Parser for the dynamic linking dylink.0 custom section.
• ElementSectionReader
  A reader for the element section of a WebAssembly module.
• ExportSectionReader
  A reader for the export section of a WebAssembly module.
• FunctionSectionReader
  A reader for the function section of a WebAssembly module.
• GlobalSectionReader
  A reader for the global section of a WebAssembly module.
• ImportSectionReader
  A reader for the import section of a WebAssembly module.
• IndirectNameMap
  Represents a reader for indirect names from the names custom section.
• InitFuncMap
  Represents a reader for init functions from the linking custom section.
• InstanceSectionReader
  A reader for the core instance section of a WebAssembly component.
• MemorySectionReader
  A reader for the memory section of a WebAssembly module.
• NameMap
  Represents a name map from the names custom section.
• NameSectionReader
  A reader for the name custom section of a WebAssembly module.
• ProducersSectionReader
  A reader for the producers custom section of a WebAssembly module.
• RelocationEntryReader
  Reader for relocation entries within a reloc.* section.
• Result
  The result for BinaryReader operations.
• SegmentMap
  Represents a reader for segments from the linking custom section.
• SymbolInfoMap
  Represents a reader for symbol info from the linking custom section.
• TableSectionReader
  A reader for the table section of a WebAssembly module.
• TagSectionReader
  A reader for the tags section of a WebAssembly module.
• TypeSectionReader
  A reader for the type section of a WebAssembly module.