/// <summary>
/// Reads the child instructions of a WebAssembly block from the given reader.
/// </summary>
/// <param name="blockType">The type of value returned by the resulting block.</param>
/// <param name="reader">The WebAssembly file reader.</param>
/// <returns>A WebAssembly block instruction.</returns>
public static IfElseInstruction ReadBlockContents(WasmType blockType, BinaryWasmReader reader)
{
var ifBranch = new List <Instruction>();
List <Instruction> elseBranch = null;
while (true)
{
byte opCode = reader.ReadByte();
if (opCode == Operators.EndOpCode)
{
return(new IfElseInstruction(blockType, ifBranch, elseBranch));
}
else if (opCode == Operators.ElseOpCode)
{
if (elseBranch != null)
{
throw new WasmException("More than one 'else' opcode in an 'if' instruction");
}
elseBranch = new List <Instruction>();
}
else
{
var op = Operators.GetOperatorByOpCode(opCode);
(elseBranch == null ? ifBranch : elseBranch).Add(op.ReadImmediates(reader));
}
}
}
/// <summary>
/// Reads the child instructions of a WebAssembly block from the given reader.
/// </summary>
/// <param name="BlockType">The type of value returned by the resulting block.</param>
/// <param name="Reader">The WebAssembly file reader.</param>
/// <returns>A WebAssembly block instruction.</returns>
public BlockInstruction ReadBlockContents(WasmType BlockType, BinaryWasmReader Reader)
{
var contents = new List <Instruction>();
while (true)
{
byte opCode = Reader.ReadByte();
if (opCode == Operators.EndOpCode)
{
return(Create(BlockType, contents));
}
else
{
var op = Operators.GetOperatorByOpCode(opCode);
contents.Add(op.ReadImmediates(Reader));
}
}
}
/// <summary>
/// Reads the export section with the given header.
/// </summary>
/// <param name="header">The section header.</param>
/// <param name="reader">A reader for a binary WebAssembly file.</param>
/// <returns>The parsed section.</returns>
public static ExportSection ReadSectionPayload(
SectionHeader header, BinaryWasmReader reader)
{
long startPos = reader.Position;
// Read the function indices.
uint count = reader.ReadVarUInt32();
var exportedVals = new List <ExportedValue>();
for (uint i = 0; i < count; i++)
{
exportedVals.Add(
new ExportedValue(
reader.ReadString(),
(ExternalKind)reader.ReadByte(),
reader.ReadVarUInt32()));
}
// Skip any remaining bytes.
var extraPayload = reader.ReadRemainingPayload(startPos, header);
return(new ExportSection(exportedVals, extraPayload));
}
/// <summary>
/// Reads an imported value from the given binary WebAssembly reader.
/// </summary>
/// <param name="Reader">The WebAssembly reader.</param>
/// <returns>The imported value that was read.</returns>
public static ImportedValue ReadFrom(BinaryWasmReader Reader)
{
string moduleName = Reader.ReadString();
string fieldName = Reader.ReadString();
var kind = (ExternalKind)Reader.ReadByte();
switch (kind)
{
case ExternalKind.Function:
return(new ImportedFunction(moduleName, fieldName, Reader.ReadVarUInt32()));
case ExternalKind.Global:
return(new ImportedGlobal(moduleName, fieldName, GlobalType.ReadFrom(Reader)));
case ExternalKind.Memory:
return(new ImportedMemory(moduleName, fieldName, MemoryType.ReadFrom(Reader)));
case ExternalKind.Table:
return(new ImportedTable(moduleName, fieldName, TableType.ReadFrom(Reader)));
default:
throw new WasmException("Unknown imported value kind: " + kind);
}
}