public WebAssemblyExecutionContext(WebAssemblyFile file)
{
if (file.table != null)
{
InitTable(file);
}
if (file.global != null)
{
InitGlobal(file);
}
if (file.memory != null)
{
InitMemory(file);
}
if (file.data != null)
{
InitData(file);
}
if (file.import != null)
{
InitImport(file);
}
InitFunctions(file);
if (file.export != null)
{
InitExport(file);
}
// TODO: InitElement(ctx);
}
public WebAssemblyInterpreter(WebAssemblyFile file)
{
this.file = file;
if (file.type == null)
{
throw new Exception("No type information!");
}
if (file.function == null)
{
throw new Exception("No type information!");
}
if (file.code == null)
{
throw new Exception("No code to execute!");
}
if (file.start == null)
{
throw new Exception("No start function!");
}
ctx = new WebAssemblyExecutionContext(file);
ResolveExternalFunctions();
uint start_func = file.start.index;
logger.Debug($"Start function index is {start_func}. This index does {(ctx.functions.ContainsKey(start_func) ? "" : "not")} exist.");
if (!ctx.functions.ContainsKey(start_func))
{
throw new Exception("Corrupt file.");
}
}
private void InitFunctions(WebAssemblyFile file)
{
logger.Debug("Instanciating Functions.");
Dictionary <uint, FuncType> type_info = new Dictionary <uint, FuncType>();
for (uint i = 0; i < (uint)file.type.entries.Length; i++)
{
type_info[i] = file.type.entries[i];
logger.ConditionalTrace($"Type {i} = {file.type.entries[i]}.");
}
logger.ConditionalTrace($"file.function.types.Length = {file.function.types.Length} and file.code.bodies.Length = {file.code.bodies.Length}.");
if (file.function.types.Length != file.code.bodies.Length)
{
throw new Exception("Invalid file");
}
uint import_count = (uint)functions.Count;
logger.ConditionalTrace($"Import count = {import_count}.");
for (uint i = 0; i < (uint)file.code.bodies.Length; i++)
{
uint index = file.function.types[i];
FunctionBody body = file.code.bodies[i];
uint func_indx = i + import_count;
logger.ConditionalTrace($"Function {func_indx} = {body}.");
functions[func_indx] = new FunctionInstance
{
module = "this",
is_in_module = true,
code = body.code,
parameters = type_info[index].param_types,
return_type = type_info[index].return_type,
};
List <WebAssemblyType> locals_unwrapped = new List <WebAssemblyType>();
foreach (var local in body.locals)
{
locals_unwrapped.AddRange(Enumerable.Repeat(local.type, (int)local.count));
}
functions[func_indx].locals = locals_unwrapped.ToArray();
logger.ConditionalTrace($"Final object = {functions[func_indx]}.");
}
logger.Debug("Done instanciating Functions.");
}
private void InitData(WebAssemblyFile file)
{
logger.Debug("Instanciating Data.");
foreach (var entry in file.data.entries)
{
var offset = WebAssemblyHelper.GetOffset(entry.offset);
logger.ConditionalTrace($"Copying: {BitConverter.ToString(entry.data).Replace("-", "")} to [{offset},{offset + entry.data.Length}].");
Array.Copy(entry.data, 0, linear_memory[entry.memory_index].memory, offset, entry.data.Length);
}
logger.Debug("Done instanciating Data.");
}
private void InitMemory(WebAssemblyFile file)
{
logger.Debug("Instanciating Memory.");
for (uint i = 0; i < (uint)file.memory.entries.Length; i++)
{
var limits = file.memory.entries[i].limits;
logger.ConditionalTrace($"Instanciating MemoryInstance({limits.initial}, {limits.maximum}).");
linear_memory[i] = new MemoryInstance(limits.initial, limits.maximum);
}
logger.Debug("Done instanciating Memory.");
}
private void InitTable(WebAssemblyFile file)
{
logger.Debug("Instanciating Table.");
for (uint i = 0; i < (uint)file.table.entries.Length; i++)
{
var entry = file.table.entries[i];
logger.ConditionalTrace($"Instanciating TableInstance({entry.element_type}, {entry.limits.initial}, {entry.limits.maximum ?? 0}).");
tables[i] = new TableInstance(entry.element_type, entry.limits.initial, entry.limits.maximum);
}
logger.Debug("Done instanciating Table.");
}
private void InitGlobal(WebAssemblyFile file)
{
logger.Debug("Instanciating Globals.");
List <GlobalInstance> finalized_globals = new List <GlobalInstance>();
for (uint i = 0; i < (uint)file.global.globals.Length; i++)
{
var global = file.global.globals[i];
var value = WebAssemblyHelper.GetInitExpr(global.init, finalized_globals);
logger.ConditionalTrace($"Instanciating GlobalInstance({global.type.mutability}, {global.type.content_type}, {value}).");
globals[i] = new GlobalInstance(global.type.mutability, global.type.content_type, value);
finalized_globals.Add(globals[i]);
}
logger.Debug("Done instanciating Globals.");
}
private void InitExport(WebAssemblyFile file)
{
logger.Debug("Instanciating Export.");
for (uint i = 0; i < (uint)file.export.entries.Length; i++)
{
var entry = file.export.entries[i];
logger.ConditionalTrace($"Export is {entry.index}: {entry.kind} {entry.field_str}.");
switch (entry.kind)
{
case WebAssemblyExternalKind.Function:
var index = entry.index;
functions[index].is_export = true;
functions[index].name = entry.field_str;
break;
}
}
logger.Debug("Done instanciating Export.");
}
private void InitImport(WebAssemblyFile file)
{
logger.Debug("Instanciating Export.");
Dictionary <uint, FuncType> type_info = new Dictionary <uint, FuncType>();
for (uint i = 0; i < (uint)file.type.entries.Length; i++)
{
type_info[i] = file.type.entries[i];
logger.ConditionalTrace($"Type {i} = {file.type.entries[i]}.");
}
for (uint i = 0; i < (uint)file.import.entries.Length; i++)
{
var entry = file.import.entries[i];
logger.Debug($"Entry = {entry}.");
switch (entry.kind)
{
case WebAssemblyExternalKind.Function:
uint index = (uint)entry.type;
functions[i] = new FunctionInstance
{
module = entry.module_str,
name = entry.field_str,
parameters = type_info[index].param_types,
return_type = type_info[index].return_type
};
logger.ConditionalTrace($"Function {i} = {functions[i]}.");
break;
}
}
logger.Debug("Done instanciating Export.");
}