wasmer 7.2.0-rc.1

mod env;
use std::sync::Arc;

pub use env::*;

use super::{
    bindings::*, entities::function::env::FunctionEnv, function::Function, global::Global,
    memory::Memory, table::Table,
};
use crate::{
    AsStoreMut, BackendFunction, BackendGlobal, BackendMemory, BackendTable, Extern,
    v8::store::Store,
};
use wasmer_types::{MemoryError, RawValue};

pub use super::error::Trap;

pub(crate) type VMExtern = *mut wasm_extern_t;

// No EH for now.
pub(crate) type VMException = ();
pub(crate) type VMTag = *mut wasm_tag_t;
pub(crate) type VMExternTag = *mut wasm_tag_t;

pub(crate) type VMFunction = *mut wasm_func_t;
pub(crate) type VMFunctionBody = ();
pub(crate) type VMFunctionCallback = *mut ::std::os::raw::c_void;
pub(crate) type VMTrampoline = *mut ::std::os::raw::c_void;
pub(crate) type VMExternFunction = *mut wasm_func_t;

pub(crate) type VMGlobal = *mut wasm_global_t;
pub(crate) type VMExternGlobal = *mut wasm_global_t;

pub(crate) type VMTable = *mut wasm_table_t;
pub(crate) type VMExternTable = *mut wasm_table_t;

pub(crate) type VMInstance = *mut wasm_instance_t;

pub(crate) type VMExternObj = ();
pub(crate) type VMConfig = ();

#[allow(clippy::not_unsafe_ptr_arg_deref, clippy::unnecessary_mut_passed)]
#[allow(nonstandard_style)]
impl crate::VMExternToExtern for VMExtern {
    fn to_extern(self, store: &mut impl AsStoreMut) -> Extern {
        let kind = unsafe { wasm_extern_kind(&mut *self) };

        match kind as wasm_valkind_enum {
            wasm_externkind_enum_WASM_EXTERN_FUNC => {
                let func = unsafe { wasm_extern_as_func(&mut *self) };
                if func.is_null() {
                    panic!("V8 reported extern as function, but is not");
                }
                Extern::Function(crate::Function::from_vm_extern(
                    store,
                    crate::vm::VMExternFunction::V8(func),
                ))
            }
            wasm_externkind_enum_WASM_EXTERN_GLOBAL => {
                let global = unsafe { wasm_extern_as_global(&mut *self) };
                if global.is_null() {
                    panic!("V8 reported extern as a global, but is not");
                }
                Extern::Global(crate::Global::from_vm_extern(
                    store,
                    crate::vm::VMExternGlobal::V8(global),
                ))
            }
            wasm_externkind_enum_WASM_EXTERN_TABLE => {
                let table = unsafe { wasm_extern_as_table(&mut *self) };
                if table.is_null() {
                    panic!("V8 reported extern as a table, but is not");
                }
                Extern::Table(crate::Table::from_vm_extern(
                    store,
                    crate::vm::VMExternTable::V8(table),
                ))
            }
            wasm_externkind_enum_WASM_EXTERN_MEMORY => {
                let memory = unsafe { wasm_extern_as_memory(&mut *self) };
                if memory.is_null() {
                    panic!("V8 reported extern as a memory, but is not");
                }
                Extern::Memory(crate::Memory::from_vm_extern(
                    store,
                    crate::vm::VMExternMemory::V8(memory),
                ))
            }
            wasm_externkind_enum_WASM_EXTERN_TAG => {
                let tag = unsafe { wasm_extern_as_tag(&mut *self) };
                if tag.is_null() {
                    panic!("V8 reported extern as a tag, but is not");
                }
                Extern::Tag(crate::Tag::from_vm_extern(
                    store,
                    crate::vm::VMExternTag::V8(tag),
                ))
            }
            _ => {
                unimplemented!()
            }
        }
    }
}

pub(crate) struct VMExternRef(*mut wasm_ref_t);
impl VMExternRef {
    /// Converts the `VMExternRef` into a `RawValue`.
    pub fn into_raw(self) -> RawValue {
        unimplemented!()
    }

    /// Extracts a `VMExternRef` from a `RawValue`.
    ///
    /// # Safety
    /// `raw` must be a valid `VMExternRef` instance.
    pub unsafe fn from_raw(_raw: RawValue) -> Option<Self> {
        unimplemented!();
    }
}

pub(crate) struct VMFuncRef(*mut wasm_ref_t);
impl VMFuncRef {
    /// Converts the `VMExternRef` into a `RawValue`.
    pub fn into_raw(self) -> RawValue {
        unimplemented!()
    }

    /// Extracts a `VMExternRef` from a `RawValue`.
    ///
    /// # Safety
    /// `raw` must be a valid `VMExternRef` instance.
    pub unsafe fn from_raw(_raw: RawValue) -> Option<Self> {
        unimplemented!();
    }
}

pub struct VMExceptionRef(*mut wasm_ref_t);
impl VMExceptionRef {
    /// Converts the `VMExceptionRef` into a `RawValue`.
    pub fn into_raw(self) -> RawValue {
        unimplemented!()
    }

    /// Extracts a `VMExceptionRef` from a `RawValue`.
    ///
    /// # Safety
    /// `raw` must be a valid `VMExceptionRef` instance.
    pub unsafe fn from_raw(_raw: RawValue) -> Option<Self> {
        unimplemented!();
    }
}

#[derive(Debug, Clone)]
pub struct VMMemory(pub(super) *mut wasm_memory_t);
struct SharedMemoryPointer(*mut wasm_shared_memory_t);
pub struct VMSharedMemory(Arc<SharedMemoryPointer>);
pub(crate) type VMExternMemory = *mut wasm_memory_t;

impl SharedMemoryPointer {
    fn new(ptr: *mut wasm_shared_memory_t) -> Self {
        Self(ptr)
    }
}

impl Drop for SharedMemoryPointer {
    fn drop(&mut self) {
        unsafe {
            wasm_shared_memory_delete(self.0);
        }
    }
}

/// # SAFETY: The WASM V8 memory is attached to a Store and cannot be accessed
/// from a different thread (long-term goal would removal of the unsafe Send/Sync).
unsafe impl Send for VMMemory {}
unsafe impl Sync for VMMemory {}

/// # SAFETY: Shared memory handles are safe to send across thread boundaries.
unsafe impl Send for SharedMemoryPointer {}
unsafe impl Sync for SharedMemoryPointer {}

impl VMMemory {
    /// Created a shared detached memory that can be attached in another Store.
    pub(crate) fn as_shared(&self) -> Result<VMSharedMemory, MemoryError> {
        let memory_type = unsafe { wasm_memory_type(self.0) };
        let limits = unsafe { wasm_memorytype_limits(memory_type) };
        if !unsafe { (*limits).shared } {
            unsafe {
                wasm_memorytype_delete(memory_type);
            }
            return Err(MemoryError::MemoryNotShared);
        }
        unsafe {
            wasm_memorytype_delete(memory_type);
        }

        let shared = unsafe { wasm_memory_share(self.0) };
        if shared.is_null() {
            return Err(MemoryError::Generic(
                "Failed to clone the memory".to_string(),
            ));
        }

        Ok(VMSharedMemory(Arc::new(SharedMemoryPointer::new(shared))))
    }
}

impl VMSharedMemory {
    /// We can clone a shared memory handle as we want.
    pub(crate) fn clone(&self) -> Self {
        Self(self.0.clone())
    }

    /// Attach the shared memory handle to a new Store and convert it to VMMemory
    pub(crate) fn into_vm_memory(self, store: &mut Store) -> VMMemory {
        let memory = unsafe { wasm_memory_obtain(store.inner, self.0.0) };
        assert!(
            !memory.is_null(),
            "Failed to obtain V8 shared memory: wasm_memory_obtain returned null"
        );
        VMMemory(memory)
    }
}