public static void EmitObject(string objectFilePath, IEnumerable <DependencyNode> nodes, NodeFactory factory, WebAssemblyCodegenCompilation compilation, IObjectDumper dumper)
{
WebAssemblyObjectWriter objectWriter = new WebAssemblyObjectWriter(objectFilePath, factory, compilation);
bool succeeded = false;
try
{
//ObjectNodeSection managedCodeSection = null;
var listOfOffsets = new List <int>();
foreach (DependencyNode depNode in nodes)
{
ObjectNode node = depNode as ObjectNode;
if (node == null)
{
continue;
}
if (node.ShouldSkipEmittingObjectNode(factory))
{
continue;
}
objectWriter.StartObjectNode(node);
ObjectData nodeContents = node.GetData(factory);
if (dumper != null)
{
dumper.DumpObjectNode(factory.NameMangler, node, nodeContents);
}
#if DEBUG
foreach (ISymbolNode definedSymbol in nodeContents.DefinedSymbols)
{
try
{
_previouslyWrittenNodeNames.Add(definedSymbol.GetMangledName(factory.NameMangler), definedSymbol);
}
catch (ArgumentException)
{
ISymbolNode alreadyWrittenSymbol = _previouslyWrittenNodeNames[definedSymbol.GetMangledName(factory.NameMangler)];
Debug.Fail("Duplicate node name emitted to file",
$"Symbol {definedSymbol.GetMangledName(factory.NameMangler)} has already been written to the output object file {objectFilePath} with symbol {alreadyWrittenSymbol}");
}
}
#endif
ObjectNodeSection section = node.Section;
if (objectWriter.ShouldShareSymbol(node))
{
section = objectWriter.GetSharedSection(section, ((ISymbolNode)node).GetMangledName(factory.NameMangler));
}
// Ensure section and alignment for the node.
objectWriter.SetSection(section);
objectWriter.EmitAlignment(nodeContents.Alignment);
objectWriter.ResetByteRunInterruptionOffsets(nodeContents.Relocs);
// Build symbol definition map.
objectWriter.BuildSymbolDefinitionMap(node, nodeContents.DefinedSymbols);
Relocation[] relocs = nodeContents.Relocs;
int nextRelocOffset = -1;
int nextRelocIndex = -1;
if (relocs.Length > 0)
{
nextRelocOffset = relocs[0].Offset;
nextRelocIndex = 0;
}
int i = 0;
listOfOffsets.Clear();
listOfOffsets.AddRange(objectWriter._byteInterruptionOffsets);
int offsetIndex = 0;
while (i < nodeContents.Data.Length)
{
// Emit symbol definitions if necessary
objectWriter.EmitSymbolDefinition(i);
if (i == nextRelocOffset)
{
Relocation reloc = relocs[nextRelocIndex];
long delta;
unsafe
{
fixed(void *location = &nodeContents.Data[i])
{
delta = Relocation.ReadValue(reloc.RelocType, location);
}
}
int size = objectWriter.EmitSymbolReference(reloc.Target, (int)delta, reloc.RelocType);
/*
* WebAssembly has no thumb
* // Emit a copy of original Thumb2 instruction that came from RyuJIT
* if (reloc.RelocType == RelocType.IMAGE_REL_BASED_THUMB_MOV32 ||
* reloc.RelocType == RelocType.IMAGE_REL_BASED_THUMB_BRANCH24)
* {
* unsafe
* {
* fixed (void* location = &nodeContents.Data[i])
* {
* objectWriter.EmitBytes((IntPtr)location, size);
* }
* }
* }*/
// Update nextRelocIndex/Offset
if (++nextRelocIndex < relocs.Length)
{
nextRelocOffset = relocs[nextRelocIndex].Offset;
}
else
{
// This is the last reloc. Set the next reloc offset to -1 in case the last reloc has a zero size,
// which means the reloc does not have vacant bytes corresponding to in the data buffer. E.g,
// IMAGE_REL_THUMB_BRANCH24 is a kind of 24-bit reloc whose bits scatte over the instruction that
// references it. We do not vacate extra bytes in the data buffer for this kind of reloc.
nextRelocOffset = -1;
}
i += size;
}
else
{
while (offsetIndex < listOfOffsets.Count && listOfOffsets[offsetIndex] <= i)
{
offsetIndex++;
}
int nextOffset = offsetIndex == listOfOffsets.Count ? nodeContents.Data.Length : listOfOffsets[offsetIndex];
unsafe
{
// Todo: Use Span<T> instead once it's available to us in this repo
fixed(byte *pContents = &nodeContents.Data[i])
{
objectWriter.EmitBytes((IntPtr)(pContents), nextOffset - i);
i += nextOffset - i;
}
}
}
}
Debug.Assert(i == nodeContents.Data.Length);
// It is possible to have a symbol just after all of the data.
objectWriter.EmitSymbolDefinition(nodeContents.Data.Length);
objectWriter.DoneObjectNode();
}
succeeded = true;
}
finally
{
objectWriter.Dispose();
if (!succeeded)
{
// If there was an exception while generating the OBJ file, make sure we don't leave the unfinished
// object file around.
try
{
File.Delete(objectFilePath);
}
catch
{
}
}
}
}
