[browser][coreCLR] Loading WebCIL (#124904)

Author: pavelsavara

docs/design/datacontracts/Loader.md

@@ -130,6 +130,7 @@ IReadOnlyDictionary<string, TargetPointer> GetLoaderAllocatorHeaps(TargetPointer
 | `PEImageLayout` | `Base` | Base address of the image layout |
 | `PEImageLayout` | `Size` | Size of the image layout |
 | `PEImageLayout` | `Flags` | Flags associated with the PEImageLayout |
+| `PEImageLayout` | `Format` | Format discriminator (PE or Webcil) for the image layout |
 | `CGrowableSymbolStream` | `Buffer` | Pointer to the raw symbol stream buffer start |
 | `CGrowableSymbolStream` | `Size` | Size of the raw symbol stream buffer |
 | `AppDomain` | `RootAssembly` | Pointer to the root assembly |
@@ -168,6 +169,11 @@ IReadOnlyDictionary<string, TargetPointer> GetLoaderAllocatorHeaps(TargetPointer
 | `DynamicILBlobTable` | `EntrySize` | Size of each table entry |
 | `DynamicILBlobTable` | `EntryMethodToken` | Offset of each entry method token from entry address |
 | `DynamicILBlobTable` | `EntryIL` | Offset of each entry IL from entry address |
+| `WebcilHeader` | `CoffSections` | Number of COFF sections in the Webcil image |
+| `WebcilSectionHeader` | `VirtualSize` | Virtual size of the section |
+| `WebcilSectionHeader` | `VirtualAddress` | RVA of the section |
+| `WebcilSectionHeader` | `SizeOfRawData` | Size of the section's raw data |
+| `WebcilSectionHeader` | `PointerToRawData` | File offset to the section's raw data |
 
 
 
@@ -183,6 +189,7 @@ IReadOnlyDictionary<string, TargetPointer> GetLoaderAllocatorHeaps(TargetPointer
 | --- | --- | --- | --- |
 | `ASSEMBLY_NOTIFYFLAGS_PROFILER_NOTIFIED` | uint | Flag in Assembly NotifyFlags indicating the Assembly will notify profilers. | `0x1` |
 | `DefaultDomainFriendlyName` | string | Friendly name returned when `AppDomain.FriendlyName` is null (matches native `DEFAULT_DOMAIN_FRIENDLY_NAME`) | `"DefaultDomain"` |
+| `MaxWebcilSections` | ushort | Maximum number of COFF sections supported in a Webcil image (must stay in sync with native `WEBCIL_MAX_SECTIONS`) | `16` |
 
 Contracts used:
 | Contract Name |
@@ -205,6 +212,13 @@ private enum PEImageFlags : uint
 {
     FLAG_MAPPED             = 0x01, // the file is mapped/hydrated (vs. the raw disk layout)
 };
+
+// Must stay in sync with native PEImageLayout::ImageFormat values.
+private enum ImageFormat : uint
+{
+    PE = 0,
+    Webcil = 1,
+}
 ```
 
 ### Method Implementations
@@ -396,48 +410,90 @@ TargetPointer ILoader.GetILAddr(TargetPointer peAssemblyPtr, int rva)
     }
     else
     {
-        // find NT headers using DOS header
-        uint dosHeaderLfanew = target.Read<uint>(baseAddress + /* ImageDosHeader::LfanewOffset */);
-        TargetPointer ntHeadersPtr = baseAddress + dosHeaderLfanew;
+        offset = RvaToOffset(rva, peImageLayout);
+    }
+    return baseAddress + offset;
+}
 
-        TargetPointer optionalHeaderPtr = ntHeadersPtr + /* ImageNTHeaders::OptionalHeaderOffset */;
+uint RvaToOffset(int rva, Data.PEImageLayout imageLayout)
+{
+    uint format = target.Read<uint>(imageLayout + /* PEImageLayout::Format offset */);
+    if (format == (uint)ImageFormat.Webcil)
+        return WebcilRvaToOffset(rva, imageLayout);
 
-        // Get number of sections from file header
-        TargetPointer fileHeaderPtr = ntHeadersPtr + /* ImageNTHeaders::FileHeaderOffset */;
-        uint numberOfSections = target.Read<uint>(fileHeaderPtr + /* ImageFileHeader::NumberOfSectionsOffset */);
+    TargetPointer baseAddress = target.ReadPointer(imageLayout + /* PEImageLayout::Base offset */);
 
-        // Calculate first section address (after NT headers and optional header)
-        uint imageFileHeaderSize = target.Read<ushort>(fileHeaderPtr + /* ImageFileHeader::SizeOfOptionalHeaderOffset */);
-        TargetPointer firstSectionPtr = ntHeadersPtr + /* ImageNTHeaders::OptionalHeaderOffset */ + imageFileHeaderSize;
+    // find NT headers using DOS header
+    uint dosHeaderLfanew = target.Read<uint>(baseAddress + /* ImageDosHeader::LfanewOffset */);
+    TargetPointer ntHeadersPtr = baseAddress + dosHeaderLfanew;
 
-        // Find the section containing this RVA
-        TargetPointer sectionPtr = TargetPointer.Null;
-        uint sectionHeaderSize = /* sizeof(ImageSectionHeader native struct) */;
+    // Get number of sections from file header
+    TargetPointer fileHeaderPtr = ntHeadersPtr + /* ImageNTHeaders::FileHeaderOffset */;
+    uint numberOfSections = target.Read<uint>(fileHeaderPtr + /* ImageFileHeader::NumberOfSectionsOffset */);
 
-        for (uint i = 0; i < numberOfSections; i++)
-        {
-            TargetPointer currentSectionPtr = firstSectionPtr + (i * sectionHeaderSize);
-            uint virtualAddress = target.Read<uint>(currentSectionPtr + /* ImageSectionHeader::VirtualAddressOffset */);
-            uint sizeOfRawData = target.Read<uint>(currentSectionPtr + /* ImageSectionHeader::SizeOfRawDataOffset */);
+    // Calculate first section address (after NT headers and optional header)
+    uint imageFileHeaderSize = target.Read<ushort>(fileHeaderPtr + /* ImageFileHeader::SizeOfOptionalHeaderOffset */);
+    TargetPointer firstSectionPtr = ntHeadersPtr + /* ImageNTHeaders::OptionalHeaderOffset */ + imageFileHeaderSize;
 
-            if (rva >= VirtualAddress && rva < VirtualAddress + SizeOfRawData)
-            {
-                sectionPtr = currentSectionPtr;
-            }
-        }
-        if (sectionPtr == TargetPointer.Null)
+    // Find the section containing this RVA
+    TargetPointer sectionPtr = TargetPointer.Null;
+    uint sectionHeaderSize = /* sizeof(ImageSectionHeader native struct) */;
+
+    for (uint i = 0; i < numberOfSections; i++)
+    {
+        TargetPointer currentSectionPtr = firstSectionPtr + (i * sectionHeaderSize);
+        uint virtualAddress = target.Read<uint>(currentSectionPtr + /* ImageSectionHeader::VirtualAddressOffset */);
+        uint sizeOfRawData = target.Read<uint>(currentSectionPtr + /* ImageSectionHeader::SizeOfRawDataOffset */);
+
+        if (rva >= virtualAddress && rva < virtualAddress + sizeOfRawData)
         {
-            throw new InvalidOperationException("Failed to read from image.");
+            sectionPtr = currentSectionPtr;
         }
-        else
+    }
+    if (sectionPtr == TargetPointer.Null)
+    {
+        throw new InvalidOperationException("Failed to read from image.");
+    }
+
+    // Convert RVA to file offset using section information
+    uint sectionVirtualAddress = target.Read<uint>(sectionPtr + /* ImageSectionHeader::VirtualAddressOffset */);
+    uint sectionPointerToRawData = target.Read<uint>(sectionPtr + /* ImageSectionHeader::PointerToRawDataOffset */);
+    return (rva - sectionVirtualAddress) + sectionPointerToRawData;
+}
+
+uint WebcilRvaToOffset(int rva, Data.PEImageLayout imageLayout)
+{
+    if (rva < 0)
+        throw new InvalidOperationException("Negative RVA in Webcil image.");
+
+    TargetPointer headerBase = imageLayout.Base;
+    Data.WebcilHeader webcilHeader = // read WebcilHeader at headerBase
+    uint webcilHeaderSize = /* sizeof(WebcilHeader) from type info */;
+    uint webcilSectionSize = /* sizeof(WebcilSectionHeader) from type info */;
+
+    ushort numSections = webcilHeader.CoffSections;
+    if (numSections == 0 || numSections > MaxWebcilSections)
+        throw new InvalidOperationException("Invalid Webcil section count.");
+
+    TargetPointer sectionTableBase = headerBase + webcilHeaderSize;
+
+    for (int i = 0; i < numSections; i++)
+    {
+        TargetPointer sectionPtr = sectionTableBase + (uint)(i * (int)webcilSectionSize);
+        Data.WebcilSectionHeader section = // read WebcilSectionHeader at sectionPtr
+
+        uint rvaUnsigned = (uint)rva;
+        if (rvaUnsigned >= section.VirtualAddress)
         {
-            // Convert RVA to file offset using section information
-            uint sectionVirtualAddress = target.Read<uint>(sectionPtr + /* ImageSectionHeader::VirtualAddressOffset */);
-            uint sectionPointerToRawData = target.Read<uint>(sectionPtr + /* ImageSectionHeader::PointerToRawDataOffset */);
-            offset = ((rva - sectionVirtualAddress) + sectionPointerToRawData);
+            uint offset = rvaUnsigned - section.VirtualAddress;
+            if (offset < section.VirtualSize && offset < section.SizeOfRawData)
+            {
+                return offset + section.PointerToRawData;
+            }
         }
     }
-    return baseAddress + offset;
+
+    throw new InvalidOperationException("Failed to resolve RVA in Webcil image.");
 }
 
 bool TryGetSymbolStream(ModuleHandle handle, out TargetPointer buffer, out uint size)

eng/testing/tests.browser.targets

@@ -59,10 +59,9 @@
     <WasmTestLogExitCode>true</WasmTestLogExitCode>
   </PropertyGroup>
 
-  <!-- TODO-WASM https://github.com/dotnet/runtime/issues/120248 (CoreCLR on wasm defaults) -->
+  <!-- TODO-WASM https://github.com/dotnet/runtime/issues/120226 (CoreCLR on wasm defaults) -->
   <PropertyGroup Condition="'$(RuntimeFlavor)' == 'CoreCLR'">
     <InvariantGlobalization Condition="'$(InvariantGlobalization)' == ''">false</InvariantGlobalization>
-    <WasmEnableWebcil>false</WasmEnableWebcil>
   </PropertyGroup>
 
   <ItemGroup>

src/coreclr/clrdefinitions.cmake

@@ -148,6 +148,10 @@ if(FEATURE_OBJCMARSHAL)
   add_compile_definitions(FEATURE_OBJCMARSHAL)
 endif()
 
+if(FEATURE_WEBCIL)
+  add_compile_definitions(FEATURE_WEBCIL)
+endif()
+
 add_compile_definitions($<${FEATURE_JAVAMARSHAL}:FEATURE_JAVAMARSHAL>)
 
 add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:DAC_COMPONENT>>>:FEATURE_PROFAPI_ATTACH_DETACH>)

src/coreclr/clrfeatures.cmake

@@ -43,6 +43,10 @@ if(CLR_CMAKE_TARGET_ARCH_WASM)
   set(FEATURE_PORTABLE_HELPERS 1)
 endif(CLR_CMAKE_TARGET_ARCH_WASM)
 
+if(CLR_CMAKE_TARGET_BROWSER)
+  set(FEATURE_WEBCIL 1)
+endif()
+
 if(NOT DEFINED FEATURE_INTERPRETER)
   if(CLR_CMAKE_TARGET_ANDROID)
     set(FEATURE_INTERPRETER 0)