wasmex
v0.8.3

Wasmex.EngineConfig (wasmex v0.8.3)

Configures a Wasmex.Engine.

options

 Options

  • :consume_fuel - Whether or not to consume fuel when executing Wasm instructions. This defaults to false.
  • :cranelift_opt_level - Optimization level for the Cranelift code generator. This defaults to :none.
  • :wasm_backtrace_details - Whether or not backtraces in traps will parse debug info in the Wasm file to have filename/line number information. This defaults to false.

example

 Example 

iex> _config = %Wasmex.EngineConfig{}
...>           |> Wasmex.EngineConfig.consume_fuel(true)
...>           |> Wasmex.EngineConfig.cranelift_opt_level(:speed)
...>           |> Wasmex.EngineConfig.wasm_backtrace_details(false)

Link to this section Summary

Types

t()

Functions

consume_fuel(config, consume_fuel)

Configures whether execution of WebAssembly will "consume fuel" to either halt or yield execution as desired.

cranelift_opt_level(config, cranelift_opt_level)

Configures the Cranelift code generator optimization level.

wasm_backtrace_details(config, wasm_backtrace_details)

Configures whether backtraces in traps will parse debug info in the Wasm file to have filename/line number information.

Link to this section Types

Link to this type

t()

@type t() :: %Wasmex.EngineConfig{
  consume_fuel: boolean(),
  cranelift_opt_level: :none | :speed | :speed_and_size,
  wasm_backtrace_details: boolean()
}

Link to this section Functions

Link to this function

consume_fuel(config, consume_fuel)

@spec consume_fuel(t(), boolean()) :: t()

Configures whether execution of WebAssembly will "consume fuel" to either halt or yield execution as desired.

This can be used to deterministically prevent infinitely-executing WebAssembly code by instrumenting generated code to consume fuel as it executes. When fuel runs out a trap is raised.

Note that a Wasmex.Store starts with no fuel, so if you enable this option you'll have to be sure to pour some fuel into Wasmex.Store before executing some code. See Wasmex.StoreOrCaller.add_fuel/2.

example

 Example 

iex> config = %Wasmex.EngineConfig{}
...>          |> Wasmex.EngineConfig.consume_fuel(true)
iex> config.consume_fuel
true
Link to this function

cranelift_opt_level(config, cranelift_opt_level)

@spec cranelift_opt_level(t(), :none | :speed | :speed_and_size) :: t()

Configures the Cranelift code generator optimization level.

Allows one of the following values:

  • :none - No optimizations performed, minimizes compilation time by disabling most optimizations.
  • :speed - Generates the fastest possible code, but may take longer.
  • :speed_and_size - Similar to speed, but also performs transformations aimed at reducing code size.
Link to this function

wasm_backtrace_details(config, wasm_backtrace_details)

@spec wasm_backtrace_details(t(), boolean()) :: t()

Configures whether backtraces in traps will parse debug info in the Wasm file to have filename/line number information.

When enabled this will causes modules to retain debugging information found in Wasm binaries. This debug information will be used when a trap happens to symbolicate each stack frame and attempt to print a filename/line number for each Wasm frame in the stack trace.

example

 Example 

iex> config = %Wasmex.EngineConfig{}
...>          |> Wasmex.EngineConfig.wasm_backtrace_details(true)
iex> config.wasm_backtrace_details
true