
Security News
Engineering with AI Podcast: The Promise of AI-First Development
Socket CTO Ahmad Nassri shares practical AI coding techniques, tools, and team workflows, plus what still feels noisy and why shipping remains human-led.
binaryen
Advanced tools
Browser & Node.js builds of Binaryen, a compiler infrastructure and toolchain library for WebAssembly.
binaryen.js is a port of Binaryen to the Web, allowing you to generate WebAssembly using a JavaScript API.
$> npm install binaryen
import binaryen from "binaryen";
// Create a module with a single function
var myModule = new binaryen.Module();
myModule.addFunction("add", binaryen.createType([ binaryen.i32, binaryen.i32 ]), binaryen.i32, [ binaryen.i32 ],
myModule.block(null, [
myModule.local.set(2,
myModule.i32.add(
myModule.local.get(0, binaryen.i32),
myModule.local.get(1, binaryen.i32)
)
),
myModule.return(
myModule.local.get(2, binaryen.i32)
)
])
);
myModule.addFunctionExport("add", "add");
// Optimize the module using default passes and levels
myModule.optimize();
// Validate the module
if (!myModule.validate())
throw new Error("validation error");
// Generate text format and binary
var textData = myModule.emitText();
var wasmData = myModule.emitBinary();
// Example usage with the WebAssembly API
var compiled = new WebAssembly.Module(wasmData);
var instance = new WebAssembly.Instance(compiled, {});
console.log(instance.exports.add(41, 1));
The buildbot also publishes nightly versions once a day if there have been changes. The latest nightly can be installed through
$> npm install binaryen@nightly
or you can use one of the previous versions instead if necessary.
https://cdn.jsdelivr.net/gh/AssemblyScript/binaryen.js@VERSION/index.jshttps://cdn.jsdelivr.net/npm/binaryen@VERSION/index.jshttps://unpkg.com/binaryen@VERSION/index.jsReplace VERSION with a specific version or omit it (not recommended in production) to use main/latest.
The package includes Node.js builds of Binaryen's command line tools: wasm-shell, wasm-opt, wasm-metadce, wasm2js, wasm-as, wasm-dis, wasm-ctor-eval, wasm-reduce and wasm-merge.
Please note that the Binaryen API is evolving fast and that definitions and documentation provided by the package tend to get out of sync despite our best efforts. It's a bot after all. If you rely on binaryen.js and spot an issue, please consider sending a PR our way by updating index.d.ts and README.md to reflect the current API.
Future features 🦄 might not be supported by all runtimes.
none: Type
The none type, e.g., void.
i32: Type
32-bit integer type.
i64: Type
64-bit integer type.
f32: Type
32-bit float type.
f64: Type
64-bit float (double) type.
v128: Type
128-bit vector type. 🦄
funcref: Type
A function reference. 🦄
externref: Type
An external (host) reference. 🦄
anyref: Type
Any (top type) reference. 🦄
eqref: Type
Equal reference. 🦄
i31ref: Type
i31 reference. 🦄
structref: Type
Structure reference. 🦄
stringref: Type
String reference. 🦄
unreachable: Type
Special type indicating unreachable code when obtaining information about an expression.
auto: Type
Special type used in Module#block exclusively. Lets the API figure out a block's result type automatically.
createType(types: Type[]): Type
Creates a multi-value type from an array of types.
expandType(type: Type): Type[]
Expands a multi-value type to an array of types.
new Module()
Constructs a new module.
parseText(text: string): Module
Creates a module from Binaryen's s-expression text format (not official stack-style text format).
readBinary(data: Uint8Array): Module
Creates a module from binary data.
Module#addFunction(name: string, params: Type, results: Type, vars: Type[], body: ExpressionRef): FunctionRef
Adds a function. vars indicate additional locals, in the given order.
Module#getFunction(name: string): FunctionRef
Gets a function, by name,
Module#removeFunction(name: string): void
Removes a function, by name.
Module#getNumFunctions(): number
Gets the number of functions within the module.
Module#getFunctionByIndex(index: number): FunctionRef
Gets the function at the specified index.
Module#addFunctionImport(internalName: string, externalModuleName: string, externalBaseName: string, params: Type, results: Type): void
Adds a function import.
Module#addTableImport(internalName: string, externalModuleName: string, externalBaseName: string): void
Adds a table import. There's just one table for now, using name "0".
Module#addMemoryImport(internalName: string, externalModuleName: string, externalBaseName: string): void
Adds a memory import. There's just one memory for now, using name "0".
Module#addGlobalImport(internalName: string, externalModuleName: string, externalBaseName: string, globalType: Type): void
Adds a global variable import. Imported globals must be immutable.
Module#addFunctionExport(internalName: string, externalName: string): ExportRef
Adds a function export.
Module#addTableExport(internalName: string, externalName: string): ExportRef
Adds a table export. There's just one table for now, using name "0".
Module#addMemoryExport(internalName: string, externalName: string): ExportRef
Adds a memory export. There's just one memory for now, using name "0".
Module#addGlobalExport(internalName: string, externalName: string): ExportRef
Adds a global variable export. Exported globals must be immutable.
Module#getNumExports(): number
Gets the number of exports witin the module.
Module#getExportByIndex(index: number): ExportRef
Gets the export at the specified index.
Module#removeExport(externalName: string): void
Removes an export, by external name.
Module#addGlobal(name: string, type: Type, mutable: number, value: ExpressionRef): GlobalRef
Adds a global instance variable.
Module#getGlobal(name: string): GlobalRef
Gets a global, by name,
Module#removeGlobal(name: string): void
Removes a global, by name.
Module#setMemory(initial: number, maximum: number, exportName: string | null, segments: MemorySegment[], shared?: boolean): void
Sets the memory. There's just one memory for now, using name "0". Providing exportName also creates a memory export.
ExpressionRefUint8ArraybooleanModule#getNumMemorySegments(): number
Gets the number of memory segments within the module.
Module#getMemorySegmentInfo(name: string): MemorySegmentInfo
Gets information about the memory segment at the specified index.
numberUint8ArraybooleanModule#getStart(): FunctionRef
Gets the start function, if any.
Module#setStart(start: FunctionRef): void
Sets the start function.
Module#getFeatures(): Features
Gets the WebAssembly features enabled for this module.
Note that the return value may be a bitmask indicating multiple features. Possible feature flags are:
FeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesFeaturesModule#setFeatures(features: Features): void
Sets the WebAssembly features enabled for this module.
Module#addCustomSection(name: string, contents: Uint8Array): void
Adds a custom section to the binary.
getFunctionInfo(ftype: FunctionRef: FunctionInfo
Obtains information about a function.
stringstring | null (if imported)string | null (if imported)TypeTypeTypeTypeExpressionRefgetGlobalInfo(global: GlobalRef): GlobalInfo
Obtains information about a global.
stringstring | null (if imported)string | null (if imported)TypebooleanExpressionRefgetTableInfo(table: TableRef): TableInfo
Obtains information about a table.
stringstring | null (if imported)string | null (if imported)number;number;getExportInfo(export_: ExportRef): ExportInfo
Obtains information about an export.
ExternalKindstringstringPossible ExternalKind values are:
ExternalKindExternalKindExternalKindExternalKindExternalKindgetTagInfo(tag: TagRef): TagInfo
Obtains information about a tag.
stringstring | null (if imported)string | null (if imported)TypeTypegetSideEffects(expr: ExpressionRef, features: FeatureFlags): SideEffects
Gets the side effects of the specified expression.
SideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsSideEffectsbooleantrue if valid, otherwise prints validation errors and returns false.Module#optimize(): void
Optimizes the module using the default optimization passes.
Module#optimizeFunction(func: FunctionRef | string): void
Optimizes a single function using the default optimization passes.
Module#runPasses(passes: string[]): void
Runs the specified passes on the module.
Module#runPassesOnFunction(func: FunctionRef | string, passes: string[]): void
Runs the specified passes on a single function.
getOptimizeLevel(): number
Gets the currently set optimize level. 0, 1, 2 correspond to -O0, -O1, -O2 (default), etc.
setOptimizeLevel(level: number): void
Sets the optimization level to use. 0, 1, 2 correspond to -O0, -O1, -O2 (default), etc.
getShrinkLevel(): number
Gets the currently set shrink level. 0, 1, 2 correspond to -O0, -Os (default), -Oz.
setShrinkLevel(level: number): void
Sets the shrink level to use. 0, 1, 2 correspond to -O0, -Os (default), -Oz.
getDebugInfo(): boolean
Gets whether generating debug information is currently enabled or not.
setDebugInfo(on: boolean): void
Enables or disables debug information in emitted binaries.
getTrapsNeverHappen(): boolean
Gets whether no traps can be considered reached at runtime when optimizing.
setTrapsNeverHappen(on: boolean): void
Enables or disables whether no traps can be considered reached at runtime when optimizing.
getClosedWorld(): boolean
Gets whether considering that the code outside of the module does not inspect or interact with GC and function references.
setClosedWorld(on: boolean): void
Enables or disables whether considering that the code outside of the module does not inspect or interact with GC and function references.
getLowMemoryUnused(): boolean
Gets whether the low 1K of memory can be considered unused when optimizing.
setLowMemoryUnused(on: boolean): void
Enables or disables whether the low 1K of memory can be considered unused when optimizing.
getZeroFilledMemory(): boolean
Gets whether an imported memory is considered zero-initialized.
setZeroFilledMemory(on: boolean): void
Enables or disables whether an imported memory is considered zero-initialized.
getFastMath(): boolean
Gets whether fast math optimizations are enabled, ignoring for example corner cases of floating-point math like NaN changes.
setFastMath(on: boolean): void
Enables or disables fast math optimizations, ignoring for example corner cases of floating-point math like NaN changes.
getGenerateStackIR(): boolean
Gets whether to generate StackIR during binary writing.
setGenerateStackIR(on: boolean): void
Enable or disable StackIR generation during binary writing.
getOptimizeStackIR(): boolean
Gets whether to optimize StackIR during binary writing.
setOptimizeStackIR(on: boolean): void
Enable or disable StackIR optimisation during binary writing.
getPassArgument(key: string): string | null
Gets the value of the specified arbitrary pass argument.
setPassArgument(key: string, value: string | null): void
Sets the value of the specified arbitrary pass argument. Removes the respective argument if value is null.
clearPassArguments(): void
Clears all arbitrary pass arguments.
hasPassToSkip(pass: string): boolean
Gets whether a pass is in the set of passes to skip.
addPassToSkip(pass: string): void
Add a pass to the set of passes to skip.
clearPassesToSkip(): void
Clears the set of passes to skip.
getAlwaysInlineMaxSize(): number
Gets the function size at which we always inline.
setAlwaysInlineMaxSize(size: number): void
Sets the function size at which we always inline.
getFlexibleInlineMaxSize(): number
Gets the function size which we inline when functions are lightweight.
setFlexibleInlineMaxSize(size: number): void
Sets the function size which we inline when functions are lightweight.
getOneCallerInlineMaxSize(): number
Gets the function size which we inline when there is only one caller.
setOneCallerInlineMaxSize(size: number): void
Sets the function size which we inline when there is only one caller.
Module#emitBinary(): Uint8Array
Returns the module in binary format.
Module#emitBinary(sourceMapUrl: string | null): BinaryWithSourceMap
Returns the module in binary format with its source map. If sourceMapUrl is null, source map generation is skipped.
Uint8Arraystring | nullModule#emitText(): string
Returns the module in Binaryen's s-expression text format (not official stack-style text format).
Module#emitStackIR(): string
Returns the module in official stack-style text format.
Module#emitAsmjs(): string
Returns the asm.js representation of the module.
Module#dispose(): void
Releases the resources held by the module once it isn't needed anymore.
Module#block(label: string | null, children: ExpressionRef[], resultType?: Type): ExpressionRef
Creates a block. resultType defaults to none.
Module#if(condition: ExpressionRef, ifTrue: ExpressionRef, ifFalse?: ExpressionRef): ExpressionRef
Creates an if or if/else combination.
Module#loop(label: string | null, body: ExpressionRef): ExpressionRef
Creates a loop.
Module#br(label: string, condition?: ExpressionRef, value?: ExpressionRef): ExpressionRef
Creates a branch (br) to a label.
Module#switch(labels: string[], defaultLabel: string, condition: ExpressionRef, value?: ExpressionRef): ExpressionRef
Creates a switch (br_table).
Module#nop(): ExpressionRef
Creates a no-operation (nop) instruction.
Module#return(value?: ExpressionRef): ExpressionRef
Creates a return.
Module#unreachable(): ExpressionRef
Creates an unreachable instruction that will always trap.
Module#drop(value: ExpressionRef): ExpressionRef
Creates a drop of a value.
Module#select(condition: ExpressionRef, ifTrue: ExpressionRef, ifFalse: ExpressionRef): ExpressionRef
Creates a select of one of two values.
Module#local.get(index: number, type: Type): ExpressionRef
Creates a local.get for the local at the specified index. Note that we must specify the type here as we may not have created the local being accessed yet.
Module#local.set(index: number, value: ExpressionRef): ExpressionRef
Creates a local.set for the local at the specified index.
Module#local.tee(index: number, value: ExpressionRef, type: Type): ExpressionRef
Creates a local.tee for the local at the specified index. A tee differs from a set in that the value remains on the stack. Note that we must specify the type here as we may not have created the local being accessed yet.
Module#global.get(name: string, type: Type): ExpressionRef
Creates a global.get for the global with the specified name. Note that we must specify the type here as we may not have created the global being accessed yet.
Module#global.set(name: string, value: ExpressionRef): ExpressionRef
Creates a global.set for the global with the specified name.
number): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefnumber, high: number): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefnumber): ExpressionRefnumber): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefnumber): ExpressionRefnumber): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefModule#call(name: string, operands: ExpressionRef[], returnType: Type): ExpressionRef
Creates a call to a function. Note that we must specify the return type here as we may not have created the function being called yet.
Module#return_call(name: string, operands: ExpressionRef[], returnType: Type): ExpressionRef
Like call, but creates a tail-call. 🦄
Module#call_indirect(target: ExpressionRef, operands: ExpressionRef[], params: Type, results: Type): ExpressionRef
Similar to call, but calls indirectly, i.e., via a function pointer, so an expression replaces the name as the called value.
Module#return_call_indirect(target: ExpressionRef, operands: ExpressionRef[], params: Type, results: Type): ExpressionRef
Like call_indirect, but creates a tail-call. 🦄
number, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefExpressionRefnumber): ExpressionRefUint8Array): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef, cond: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number, value: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number, value: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number, value: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number, value: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, shift: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number, value: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, b: ExpressionRef, c: ExpressionRef): ExpressionRefExpressionRef, b: ExpressionRef, c: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, index: number): ExpressionRefExpressionRef, index: number, value: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, b: ExpressionRef, c: ExpressionRef): ExpressionRefExpressionRef, b: ExpressionRef, c: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef, mask: Uint8Array): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, align: number, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, value: ExpressionRef): ExpressionRefnumber, ptr: ExpressionRef, expected: ExpressionRef, replacement: ExpressionRef): ExpressionRefExpressionRef, expected: ExpressionRef, timeout: ExpressionRef): ExpressionRefExpressionRef, expected: ExpressionRef, timeout: ExpressionRef): ExpressionRefExpressionRef, notifyCount: ExpressionRef): ExpressionRefExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefNote that these are pseudo instructions enabling Binaryen to reason about multiple values on the stack.
ExpressionRef): ExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRef[]): ExpressionRefExpressionRef, index: number): ExpressionRefstring, body: ExpressionRef, catchTags: string[], catchBodies: ExpressionRef[], delegateTarget?: string): ExpressionRefstring, operands: ExpressionRef[]): ExpressionRefstring): ExpressionRefstring, params: Type, results: Type): TagRefstring): TagRefstirng): voidstring, externalModuleName: string, externalBaseName: string, params: Type, results: Type): voidstring, externalName: string): ExportRefType): ExpressionRefExpressionRef): ExpressionRefExpressionRef): ExpressionRefstring, type: Type): ExpressionRefExpressionRef): ExpressionRefExpressionRef, right: ExpressionRef): ExpressionRefstring, dest: ExpressionRef, offset: ExpressionRef, size: ExpressionRef): ExpressionRefExpressionRef, source: ExpressionRef, size: ExpressionRef): ExpressionRefExpressionRef, value: ExpressionRef, size: ExpressionRef): ExpressionRefstring): ExpressionRefgetExpressionId(expr: ExpressionRef): ExpressionId
Gets the id (kind) of the specified expression. Possible values are:
ExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdExpressionIdgetExpressionType(expr: ExpressionRef): Type
Gets the type of the specified expression.
getExpressionInfo(expr: ExpressionRef): ExpressionInfo
Obtains information about an expression, always including:
ExpressionIdTypeAdditional properties depend on the expression's id and are usually equivalent to the respective parameters when creating such an expression:
stringExpressionRef[]ExpressionRefExpressionRefExpressionRef | nullstringExpressionRefstringExpressionRef | nullExpressionRef | nullstring[]string | nullExpressionRefExpressionRef | nullstringExpressionRef[]stringExpressionRef[]ExpressionRefExpressionRef[]numberbooleannumberExpressionRefstringstringExpressionRefbooleanbooleannumbernumbernumberExpressionRefbooleannumbernumbernumberExpressionRefExpressionRefnumber | { low: number, high: number }numberExpressionRefnumberExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRef | nullExpressionRefnumbernumbernumberExpressionRefExpressionRefnumbernumberExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefTypeExpressionRefExpressionRefOpExpressionRefExpressionRefOpExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefUint8ArrayOpExpressionRefExpressionRefExpressionRefOpExpressionRefExpressionRefOpnumbernumberExpressionRefstringExpressionRefExpressionRefExpressionRefstringExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefExpressionRefOperationsExpressionRefOperationsExpressionRefstringExpressionRefExpressionRefstringExpressionRefExpressionRef[]ExpressionRef[];boolean;string;boolean;stringExpressionRef[]stringExpressionRef[]ExpressionRefnumberExpressionRefExpressionRefbooleanExpressionRefemitText(expression: ExpressionRef): string
Emits the expression in Binaryen's s-expression text format (not official stack-style text format).
copyExpression(expression: ExpressionRef): ExpressionRef
Creates a deep copy of an expression.
new Relooper()
Constructs a relooper instance. This lets you provide an arbitrary CFG, and the relooper will structure it for WebAssembly.
Relooper#addBlock(code: ExpressionRef): RelooperBlockRef
Adds a new block to the CFG, containing the provided code as its body.
Relooper#addBranch(from: RelooperBlockRef, to: RelooperBlockRef, condition: ExpressionRef, code: ExpressionRef): void
Adds a branch from a block to another block, with a condition (or nothing, if this is the default branch to take from the origin - each block must have one such branch), and optional code to execute on the branch (useful for phis).
Relooper#addBlockWithSwitch(code: ExpressionRef, condition: ExpressionRef): RelooperBlockRef
Adds a new block, which ends with a switch/br_table, with provided code and condition (that determines where we go in the switch).
Relooper#addBranchForSwitch(from: RelooperBlockRef, to: RelooperBlockRef, indexes: number[], code: ExpressionRef): void
Adds a branch from a block ending in a switch, to another block, using an array of indexes that determine where to go, and optional code to execute on the branch.
Relooper#renderAndDispose(entry: RelooperBlockRef, labelHelper: number, module: Module): ExpressionRef
Renders and cleans up the Relooper instance. Call this after you have created all the blocks and branches, giving it the entry block (where control flow begins), a label helper variable (an index of a local we can use, necessary for irreducible control flow), and the module. This returns an expression - normal WebAssembly code - that you can use normally anywhere.
Module#addDebugInfoFileName(filename: string): number
Adds a debug info file name to the module and returns its index.
Module#getDebugInfoFileName(index: number): string | null
Gets the name of the debug info file at the specified index.
Module#setDebugLocation(func: FunctionRef, expr: ExpressionRef, fileIndex: number, lineNumber: number, columnNumber: number): void
Sets the debug location of the specified ExpressionRef within the specified FunctionRef.
voidFAQs
Browser & Node.js builds of Binaryen, a compiler infrastructure and toolchain library for WebAssembly.
The npm package binaryen receives a total of 135,828 weekly downloads. As such, binaryen popularity was classified as popular.
We found that binaryen demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
Did you know?

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Security News
Socket CTO Ahmad Nassri shares practical AI coding techniques, tools, and team workflows, plus what still feels noisy and why shipping remains human-led.

Research
/Security News
A five-month operation turned 27 npm packages into durable hosting for browser-run lures that mimic document-sharing portals and Microsoft sign-in, targeting 25 organizations across manufacturing, industrial automation, plastics, and healthcare for credential theft.

Research
Fake “Phantom Shuttle” VPN Chrome extensions (active since 2017) hijack proxy auth to intercept traffic and continuously exfiltrate user credentials to attacker infrastructure.