Struct ObjectBuilder

pub struct ObjectBuilder<'a> { /* private fields */ }

Helper structure to create an ELF file as a compilation artifact.

This structure exposes the process which Wasmtime will encode a core wasm module into an ELF file, notably managing data sections and all that good business going into the final file.

Implementations

impl<'a> ObjectBuilder<'a>

pub fn new( obj: Object<'a>, tunables: &'a Tunables, triple: Triple, ) -> ObjectBuilder<'a>

Creates a new builder for the obj specified.

pub fn push_debuginfo( &mut self, dwarf: &mut Vec<(u8, Range<u64>)>, debuginfo: &DebugInfoData<'_>, )

Insert the wasm raw wasm-based debuginfo into the output. Note that this is distinct from the native debuginfo possibly generated by the native compiler, hence these sections getting wasm-specific names.

pub fn append( &mut self, translation: ModuleTranslation<'_>, funcs: PrimaryMap<DefinedFuncIndex, CompiledFunctionInfo>, wasm_to_array_trampolines: Vec<(ModuleInternedTypeIndex, FunctionLoc)>, ) -> Result<CompiledModuleInfo>

Completes compilation of the translation specified, inserting everything necessary into the Object being built.

This function will consume the final results of compiling a wasm module and finish the ELF image in-progress as part of self.obj by appending any compiler-agnostic sections.

The auxiliary CompiledModuleInfo structure returned here has also been serialized into the object returned, but if the caller will quickly turn-around and invoke CompiledModule::from_artifacts after this then the information can be passed to that method to avoid extra deserialization. This is done to avoid a serialize-then-deserialize for API calls like Module::new where the compiled module is immediately going to be used.

The various arguments here are:

• translation - the core wasm translation that’s being completed.

• funcs - compilation metadata about functions within the translation as well as where the functions are located in the text section and any associated trampolines.

• wasm_to_array_trampolines - list of all trampolines necessary for Wasm callers calling array callees (e.g. Func::wrap). One for each function signature in the module. Must be sorted by SignatureIndex.

Returns the CompiledModuleInfo corresponding to this core Wasm module as a result of this append operation. This is then serialized into the final artifact by the caller.

pub fn serialize_info<T>(&mut self, info: &T)

where T: Serialize,

Creates the ELF_WASMTIME_INFO section from the given serializable data structure.

pub fn finish<T: WritableBuffer>(self, t: &mut T) -> Result<()>

Serializes self into a buffer. This can be used for execution as well as serialization.