Module vmcontext

This file declares VMContext and several related structs which contain fields that compiled wasm code accesses directly.

Structs

VMBuiltinFunctionsArray

An array that stores addresses of builtin functions. We translate code to use indirect calls. This way, we don’t have to patch the code.

VMCallerCheckedAnyfunc

The VM caller-checked “anyfunc” record, for caller-side signature checking. It consists of the actual function pointer and a signature id to be checked by the caller.

VMContext

The VM “context”, which is pointed to by the vmctx arg in the compiler. This has information about globals, memories, tables, and other runtime state associated with the current instance.

VMDynamicFunctionContext

The VMDynamicFunctionContext is the context that dynamic functions will receive when called (rather than vmctx). A dynamic function is a function for which we don’t know the signature until runtime.

VMFunctionImport

An imported function.

VMGlobalDefinition

The storage for a WebAssembly global defined within the instance.

VMGlobalImport

The fields compiled code needs to access to utilize a WebAssembly global variable imported from another instance.

VMMemoryDefinition

The fields compiled code needs to access to utilize a WebAssembly linear memory defined within the instance, namely the start address and the size in bytes.

VMMemoryImport

The fields compiled code needs to access to utilize a WebAssembly linear memory imported from another instance.

VMSharedSignatureIndex

An index into the shared signature registry, usable for checking signatures at indirect calls.

VMSharedTagIndex

A tag index, unique within the Store in which the instance was created. Usable for translating module-local tag indices to store-unique ones.

VMTableDefinition

The fields compiled code needs to access to utilize a WebAssembly table defined within the instance.

VMTableImport

The fields compiled code needs to access to utilize a WebAssembly table imported from another instance.

Enums

VMFunctionKind

A function kind is a calling convention into and out of wasm code.

Functions

memory32_atomic_check32 🔒 ^⚠

Perform the memory32.atomic.check32 operation for the memory. Return 0 if same, 1 if different

memory32_atomic_check64 🔒 ^⚠

Perform the memory32.atomic.check64 operation for the memory. Return 0 if same, 1 if different

memory_copy 🔒 ^⚠

Do an unsynchronized, non-atomic memory.copy for the memory.

memory_fill 🔒 ^⚠

Perform the memory.fill operation for the memory in an unsynchronized, non-atomic way.

Type Aliases

VMTrampoline

The type for tramplines in the VM.

Unions

VMFunctionContext

Union representing the first parameter passed when calling a function.