fpc/packages/wasmtime/examples/wasi.pp
2023-10-30 09:17:01 +01:00

117 lines
3.3 KiB
ObjectPascal

{$mode objfpc}
{$h+}
program wasi;
uses classes,ctypes, wasmtime;
procedure exit_with_error(message : PAnsiChar; error : Pwasmtime_error_t; trap: Pwasm_trap_t); cdecl;
var
error_message : Twasm_byte_vec_t ;
S : AnsiString;
begin
Writeln(stderr, 'error: ', message);
S:='';
if Trap<>nil then
begin
write('Trap: ');
wasm_trap_message(trap, @error_message);
wasm_trap_delete(trap);
end
else
begin
write('Error: ');
wasmtime_error_message(error, @error_message);
wasmtime_error_delete(error)
end;
SetLength(S,error_message.size);
Move(error_message.data^,S[1],error_message.size);
Writeln(stderr, '>>',S,'<<');
wasm_byte_vec_delete(@error_message);
halt(1);
end;
Var
engine : Pwasm_engine_t = Nil;
store : Pwasmtime_store_t = Nil;
context : Pwasmtime_context_t = Nil;
F : TMemoryStream;
wasm : twasm_byte_vec_t;
module : Pwasmtime_module_t = Nil;
error : Pwasmtime_error_t = Nil;
func : Twasmtime_func_t;
trap : Pwasm_trap_t = Nil;
linker : Pwasmtime_linker_t;
wasi_config : Pwasi_config_t;
status : cint;
begin
Writeln('Loading wasm library');
Loadwasmtime('./'+libwasmtime);
Writeln('Initializing...');
engine := wasm_engine_new();
store:=wasmtime_store_new(engine, nil,nil);
context:=wasmtime_store_context(store);
linker:= wasmtime_linker_new(engine);
error:=wasmtime_linker_define_wasi(linker);
if (error<>Nil) then
exit_with_error('failed to define link wasi', error, Nil);
F:=TMemoryStream.Create;
try
F.LoadFromFile('hello.wasm');
wasm_byte_vec_new_uninitialized(@wasm, F.Size);
Move(F.Memory^,wasm.data^,F.Size);
finally
F.Free;
end;
// Now that we've got our binary webassembly we can compile our module.
Writeln('Compiling module...');
error:=wasmtime_module_new(engine, Puint8_t(wasm.data), wasm.size, @module);
wasm_byte_vec_delete(@wasm);
if (error <> nil) then
exit_with_error('failed to compile module', error, nil);
wasi_config:=wasi_config_new();
if (wasi_config=nil) then
exit_with_error('failed to create wasi config', Nil, nil);
wasi_config_inherit_argv(wasi_config);
wasi_config_inherit_env(wasi_config);
wasi_config_inherit_stdin(wasi_config);
wasi_config_inherit_stdout(wasi_config);
wasi_config_inherit_stderr(wasi_config);
wasi_config_preopen_dir(wasi_config,PAnsiChar('.'),PAnsiChar('.'));
error:=wasmtime_context_set_wasi(context, wasi_config);
if (error<>Nil) then
exit_with_error('failed to instantiate WASI', error, nil);
// Instantiate the module
error:=wasmtime_linker_module(linker, context, Nil, 0, module);
if (error<>nil) then
exit_with_error('failed to instantiate module', Nil, Nil);
error:=wasmtime_linker_get_default(linker, context, nil, 0, @func);
if (error<>nil) then
exit_with_error('failed to locate default export for module', error, nil);
// And call it!
Writeln('Calling export...');
error:=wasmtime_func_call(context, @func, nil, 0, nil, 0, @trap);
if wasmtime_error_exit_status(error,@status)<>0 then
Writeln('Wasm program exited with status: ',Status)
else
exit_with_error('Error while running default export for module', error, trap);
// Clean up after ourselves at this point
Writeln('All finished!\n');
wasmtime_module_delete(module);
wasmtime_store_delete(store);
wasm_engine_delete(engine);
end.