[−][src]Module wasmer_vm::libcalls

Runtime library calls.

Note that Wasm compilers may sometimes perform these inline rather than calling them, particularly when CPUs have special instructions which compute them directly.

These functions are called by compiled Wasm code, and therefore must take certain care about some things:

They must always be pub extern "C" and should only contain basic, raw i32/i64/f32/f64/pointer parameters that are safe to pass across the system ABI!
If any nested function propagates an Err(trap) out to the library function frame, we need to raise it. This involves some nasty and quite unsafe code under the covers! Notable, after raising the trap, drops will not be run for local variables! This can lead to things like leaking InstanceHandles which leads to never deallocating JIT code, instances, and modules! Therefore, always use nested blocks to ensure drops run before raising a trap:

ⓘThis example is not tested
```
pub extern "C" fn my_lib_function(...) {
    let result = {
        // Do everything in here so drops run at the end of the block.
        ...
    };
    if let Err(trap) = result {
        // Now we can safely raise the trap without leaking!
        raise_lib_trap(trap);
    }
}
```

Enums

LibCall

The name of a runtime library routine.

Functions

wasmer_data_drop ^⚠	Implementation of `data.drop`.
wasmer_elem_drop ^⚠	Implementation of `elem.drop`.
wasmer_f32_ceil	Implementation of f32.ceil
wasmer_f32_floor	Implementation of f32.floor
wasmer_f32_nearest	Implementation of f32.nearest
wasmer_f32_trunc	Implementation of f32.trunc
wasmer_f64_ceil	Implementation of f64.ceil
wasmer_f64_floor	Implementation of f64.floor
wasmer_f64_nearest	Implementation of f64.nearest
wasmer_f64_trunc	Implementation of f64.trunc
wasmer_imported_memory32_grow ^⚠	Implementation of memory.grow for imported 32-bit memories.
wasmer_imported_memory32_size ^⚠	Implementation of memory.size for imported 32-bit memories.
wasmer_imported_memory_copy ^⚠	Implementation of `memory.copy` for imported memories.
wasmer_imported_memory_fill ^⚠	Implementation of `memory.fill` for imported memories.
wasmer_local_memory_copy ^⚠	Implementation of `memory.copy` for locally defined memories.
wasmer_memory32_grow ^⚠	Implementation of memory.grow for locally-defined 32-bit memories.
wasmer_memory32_size ^⚠	Implementation of memory.size for locally-defined 32-bit memories.
wasmer_memory_fill ^⚠	Implementation of `memory.fill` for locally defined memories.
wasmer_memory_init ^⚠	Implementation of `memory.init`.
wasmer_probestack ^⚠	Probestack check
wasmer_raise_trap ^⚠	Implementation for raising a trap
wasmer_table_copy ^⚠	Implementation of `table.copy`.
wasmer_table_init ^⚠	Implementation of `table.init`.