/// <summary>
/// Instantiates the tables in the given WebAssembly file.
/// </summary>
/// <param name="File">The file whose tables are to be instantiated.</param>
private void InstantiateTables(WasmFile File)
{
// Create module-defined tables.
var allTableSections = File.GetSections <TableSection>();
for (int i = 0; i < allTableSections.Count; i++)
{
foreach (var tableSpec in allTableSections[i].Tables)
{
definedTables.Add(new FunctionTable(tableSpec.Limits));
}
}
// Initialize tables by applying the segments defined by element sections.
var allElementSections = File.GetSections <ElementSection>();
for (int i = 0; i < allElementSections.Count; i++)
{
foreach (var segment in allElementSections[i].Segments)
{
var table = Tables[(int)segment.TableIndex];
var evalOffset = Evaluate <int>(segment.Offset);
for (int j = 0; j < segment.Elements.Count; j++)
{
table[(uint)(evalOffset + j)] = definedFuncs[(int)segment.Elements[j]];
}
}
}
}
private void InstantiateMemories(WasmFile File)
{
// Create module-defined memories.
var allMemorySections = File.GetSections <MemorySection>();
for (int i = 0; i < allMemorySections.Count; i++)
{
var memorySection = allMemorySections[i];
foreach (var memorySpec in memorySection.Memories)
{
definedMemories.Add(new LinearMemory(memorySpec.Limits));
}
}
// Initialize memories by applying the segments defined by data sections.
var allDataSections = File.GetSections <DataSection>();
for (int i = 0; i < allDataSections.Count; i++)
{
var dataSection = allDataSections[i];
foreach (var segment in dataSection.Segments)
{
var memoryView = Memories[(int)segment.MemoryIndex].Int8;
var evalOffset = Evaluate <int>(segment.Offset);
for (int j = 0; j < segment.Data.Length; j++)
{
memoryView[(uint)(evalOffset + j)] = (sbyte)segment.Data[j];
}
}
}
}
/// <summary>
/// Instantiates all function definitions from the given WebAssembly file.
/// </summary>
/// <param name="File">A WebAssembly file.</param>
/// <param name="FunctionTypes">The list of all function types declared by the WebAssembly file.</param>
private void InstantiateFunctionDefs(WasmFile File, List <FunctionType> FunctionTypes)
{
var funcSignatures = new List <FunctionType>();
var funcBodies = new List <FunctionBody>();
var allFuncSections = File.GetSections <FunctionSection>();
for (int i = 0; i < allFuncSections.Count; i++)
{
foreach (var funcSpec in allFuncSections[i].FunctionTypes)
{
funcSignatures.Add(FunctionTypes[(int)funcSpec]);
}
}
var allCodeSections = File.GetSections <CodeSection>();
for (int i = 0; i < allCodeSections.Count; i++)
{
funcBodies.AddRange(allCodeSections[i].Bodies);
}
if (funcSignatures.Count != funcBodies.Count)
{
throw new WasmException(
"Function declaration/definition count mismatch: module declares " +
funcSignatures.Count + " functions and defines " + funcBodies.Count + ".");
}
for (int i = 0; i < funcSignatures.Count; i++)
{
DefineFunction(funcSignatures[i], funcBodies[i]);
}
}
/// <summary>
/// Exports values specified by the given WebAssembly file.
/// </summary>
/// <param name="File">The file that specifies which values are to be exported and how.</param>
private void RegisterExports(WasmFile File)
{
var allExportSections = File.GetSections <ExportSection>();
for (int i = 0; i < allExportSections.Count; i++)
{
foreach (var export in allExportSections[i].Exports)
{
switch (export.Kind)
{
case ExternalKind.Memory:
expMemories[export.Name] = Memories[(int)export.Index];
break;
case ExternalKind.Global:
expGlobals[export.Name] = Globals[(int)export.Index];
break;
case ExternalKind.Function:
expFuncs[export.Name] = Functions[(int)export.Index];
break;
case ExternalKind.Table:
expTables[export.Name] = Tables[(int)export.Index];
break;
default:
throw new WasmException("Unknown export kind: " + export.Kind);
}
}
}
}
private void InstantiateMemories(WasmFile file, uint maxMemorySize)
{
// Create module-defined memories.
var allMemorySections = file.GetSections <MemorySection>();
for (int i = 0; i < allMemorySections.Count; i++)
{
var memorySection = allMemorySections[i];
foreach (var memorySpec in memorySection.Memories)
{
if (maxMemorySize == 0)
{
definedMemories.Add(new LinearMemory(memorySpec.Limits));
}
else
{
definedMemories.Add(
new LinearMemory(
new ResizableLimits(
memorySpec.Limits.Initial,
memorySpec.Limits.HasMaximum
? Math.Min(memorySpec.Limits.Maximum.Value, maxMemorySize)
: maxMemorySize)));
}
}
}
// Initialize memories by applying the segments defined by data sections.
var allDataSections = file.GetSections <DataSection>();
for (int i = 0; i < allDataSections.Count; i++)
{
var dataSection = allDataSections[i];
foreach (var segment in dataSection.Segments)
{
var memoryView = Memories[(int)segment.MemoryIndex].Int8;
var evalOffset = Evaluate <int>(segment.Offset);
for (int j = 0; j < segment.Data.Length; j++)
{
memoryView[(uint)(evalOffset + j)] = (sbyte)segment.Data[j];
}
}
}
}
/// <summary>
/// Uses the given importer to resolve all imported values.
/// </summary>
/// <param name="Importer">The importer.</param>
private void ResolveImports(
WasmFile File,
IImporter Importer,
List <FunctionType> FunctionTypes)
{
var allImportSections = File.GetSections <ImportSection>();
for (int i = 0; i < allImportSections.Count; i++)
{
var importSection = allImportSections[i];
foreach (var import in importSection.Imports)
{
if (import is ImportedMemory)
{
var memory = Importer.ImportMemory((ImportedMemory)import);
if (memory == null)
{
ThrowCannotResolveImport(import, "linear memory");
}
definedMemories.Add(memory);
}
else if (import is ImportedGlobal)
{
var globalVar = Importer.ImportGlobal((ImportedGlobal)import);
if (globalVar == null)
{
ThrowCannotResolveImport(import, "global variable");
}
definedGlobals.Add(globalVar);
}
else if (import is ImportedFunction)
{
var funcImport = (ImportedFunction)import;
var funcDef = Importer.ImportFunction(funcImport, FunctionTypes[(int)funcImport.TypeIndex]);
if (funcDef == null)
{
ThrowCannotResolveImport(import, "function");
}
definedFuncs.Add(funcDef);
}
else if (import is ImportedTable)
{
var table = Importer.ImportTable((ImportedTable)import);
if (table == null)
{
ThrowCannotResolveImport(import, "table");
}
definedTables.Add(table);
}
else
{
throw new WasmException("Unknown import type: " + import.ToString());
}
}
}
}
/// <summary>
/// Gets a list of all function types declared by the given WebAssembly file.
/// </summary>
/// <param name="File">The WebAssembly file to examine.</param>
/// <returns>The list of function types.</returns>
private static List <FunctionType> GetFunctionTypes(WasmFile File)
{
var allFuncTypes = new List <FunctionType>();
var allTypeSections = File.GetSections <TypeSection>();
for (int i = 0; i < allTypeSections.Count; i++)
{
allFuncTypes.AddRange(allTypeSections[i].FunctionTypes);
}
return(allFuncTypes);
}
/// <summary>
/// Rewrites function type references in the given WebAssembly file
/// by replacing keys from the rewrite map with their corresponding
/// values.
/// </summary>
/// <param name="File">The WebAssembly file to rewrite.</param>
/// <param name="RewriteMap">A mapping of original type indices to new type indices.</param>
public static void RewriteFunctionTypeReferences(
this WasmFile File,
IReadOnlyDictionary <uint, uint> RewriteMap)
{
// Type references occur only in the import and function sections.
var importSections = File.GetSections <ImportSection>();
for (int i = 0; i < importSections.Count; i++)
{
var importSec = importSections[i];
for (int j = 0; j < importSec.Imports.Count; j++)
{
var importDecl = importSec.Imports[j] as ImportedFunction;
uint newIndex;
if (importDecl != null && RewriteMap.TryGetValue(importDecl.TypeIndex, out newIndex))
{
importDecl.TypeIndex = newIndex;
}
}
}
var funcSections = File.GetSections <FunctionSection>();
for (int i = 0; i < funcSections.Count; i++)
{
var funcSec = funcSections[i];
for (int j = 0; j < funcSec.FunctionTypes.Count; j++)
{
uint newIndex;
if (RewriteMap.TryGetValue(funcSec.FunctionTypes[j], out newIndex))
{
funcSec.FunctionTypes[j] = newIndex;
}
}
}
}
/// <summary>
/// Instantiates all function definitions from the given WebAssembly file.
/// </summary>
/// <param name="file">A WebAssembly file.</param>
/// <param name="compiler">A compiler to use for instantiating function definitions.</param>
/// <param name="functionTypes">The list of all function types declared by the WebAssembly file.</param>
private void InstantiateFunctionDefs(WasmFile file, ModuleCompiler compiler, List <FunctionType> functionTypes)
{
var funcSignatures = new List <FunctionType>();
var funcBodies = new List <FunctionBody>();
var allFuncSections = file.GetSections <FunctionSection>();
for (int i = 0; i < allFuncSections.Count; i++)
{
foreach (var funcSpec in allFuncSections[i].FunctionTypes)
{
funcSignatures.Add(functionTypes[(int)funcSpec]);
}
}
var allCodeSections = file.GetSections <CodeSection>();
for (int i = 0; i < allCodeSections.Count; i++)
{
funcBodies.AddRange(allCodeSections[i].Bodies);
}
if (funcSignatures.Count != funcBodies.Count)
{
throw new WasmException(
"Function declaration/definition count mismatch: module declares " +
funcSignatures.Count + " functions and defines " + funcBodies.Count + ".");
}
compiler.Initialize(this, definedFuncs.Count, funcSignatures);
for (int i = 0; i < funcSignatures.Count; i++)
{
DefineFunction(compiler.Compile(i, funcBodies[i]));
}
compiler.Finish();
}
private void InstantiateGlobals(WasmFile File)
{
// Create module-defined globals.
var allGlobalSections = File.GetSections <GlobalSection>();
for (int i = 0; i < allGlobalSections.Count; i++)
{
var globalSection = allGlobalSections[i];
foreach (var globalSpec in globalSection.GlobalVariables)
{
definedGlobals.Add(
Variable.Create <object>(
globalSpec.Type.ContentType,
globalSpec.Type.IsMutable,
Evaluate <object>(globalSpec.InitialValue)));
}
}
}