fpc/packages/wasmtime/examples/gcd.pp
Michaël Van Canneyt 0ec4203e2c * PChar -> PAnsiChar
2023-07-15 18:22:36 +02:00

109 lines
3.0 KiB
ObjectPascal

program gcd;
uses sysutils, 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);
if (error <> Nil) then
begin
wasmtime_error_message(error, @error_message);
wasmtime_error_delete(error)
end
else
begin
wasm_trap_message(trap, @error_message);
wasm_trap_delete(trap);
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;
wat : Twasm_byte_vec_t;
wasm : twasm_byte_vec_t;
module : Pwasmtime_module_t = Nil;
error : Pwasmtime_error_t = Nil;
trap : Pwasm_trap_t = Nil;
instance : Twasmtime_instance_t;
gcd_func : Twasmtime_extern_t;
ok : Byte;
a : longint = 6;
b : longint = 27;
params : Array [0..1] of twasmtime_val_t;
results : array [0..0] of twasmtime_val_t;
begin
Writeln('Loading wasm library');
Loadwasmtime('./'+libwasmtime);
Writeln('Initializing...');
gcd_func:=Default(Twasmtime_extern_t);
engine := wasm_engine_new();
store:=wasmtime_store_new(engine, nil,nil);
context:=wasmtime_store_context(store);
F:=TMemoryStream.Create;
try
F.LoadFromFile('gcd.wat');
wasm_byte_vec_new_uninitialized(@wat, F.Size);
Move(F.Memory^,wat.data^,F.Size);
finally
F.Free;
end;
error:=wasmtime_wat2wasm(PAnsiChar(wat.data), wat.size, @wasm);
if (error<>Nil) then
exit_with_error('failed to parse wat', error, Nil);
wasm_byte_vec_delete(@wat);
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);
Writeln('Instantiating module...');
error:=wasmtime_instance_new(context, module, nil, 0, @instance, @trap);
if (error<>nil) or (trap <>Nil) then
exit_with_error('failed to instantiate', error, trap);
Writeln('Extracting export...');
ok:=wasmtime_instance_export_get(context, @instance, PAnsiChar('gcd'), 3, @gcd_func) ;
if OK=0 then
exit_with_error('failed to get gcd export', nil, nil);
if gcd_func.kind<>WASMTIME_EXTERN_FUNC then
exit_with_error('gcd is not a function', nil, nil);
Writeln('Calling export...');
params[0].kind:=WASMTIME_I32;
params[0].of_.i32:=a;
params[1].kind:=WASMTIME_I32;
params[1].of_.i32:= b;
error:=wasmtime_func_call(context, @gcd_func.of_.func, @params, 2, @results, 1, @trap);
if (error<>nil) or (trap<>nil) then
exit_with_error('failed to call function', error, trap);
writeln(Format('gcd(%d, %d) = %d',[ a, b, results[0].of_.i32]));
// Clean up after ourselves at this point
Writeln('All finished!');
wasmtime_module_delete(module);
wasmtime_store_delete(store);
wasm_engine_delete(engine);
end.