Debugging

Using source maps

To enable source map support for your WebAssembly binary for example for more convenient error reporting or debugging, it is currently necessary to either:

• Include an absolute URL in the WebAssembly binary when instantiating a module from a buffer or
• If the binary includes a relative URL, instantiate the WebAssembly binary with WebAssembly.instantiateStreaming

The exact source map URL included in the binary can be provided to asc as an argument to the --sourceMap parameter. Also note that WebAssembly source maps are not supported by all browsers, yet, but it is known that latest Firefox supports them.

Articles

• Making Web Assembly Even Faster: Debugging Web Assembly Performance with AssemblyScript and a Gameboy Emulator (Aaron Turner, March 2018)