[cdac] Implement ISOSDacInterface::GetModule and IXCLRDataModule::GetFileName

docs/design/datacontracts/Loader.md

@@ -34,6 +34,7 @@ ModuleHandle GetModuleHandle(TargetPointer module);
 TargetPointer GetAssembly(ModuleHandle handle);
 ModuleFlags GetFlags(ModuleHandle handle);
 string GetPath(ModuleHandle handle);
+string GetFileName(ModuleHandle handle);
 TargetPointer GetLoaderAllocator(ModuleHandle handle);
 TargetPointer GetThunkHeap(ModuleHandle handle);
 TargetPointer GetILBase(ModuleHandle handle);
@@ -52,6 +53,7 @@ Data descriptors used:
 | `Module` | `LoaderAllocator` | LoaderAllocator of the Module |
 | `Module` | `ThunkHeap` | Pointer to the thunk heap |
 | `Module` | `Path` | Path of the Module (UTF-16, null-terminated) |
+| `Module` | `FileName` | File name of the Module (UTF-16, null-terminated) |
 | `Module` | `FieldDefToDescMap` | Mapping table |
 | `Module` | `ManifestModuleReferencesMap` | Mapping table |
 | `Module` | `MemberRefToDescMap` | Mapping table |
@@ -86,6 +88,13 @@ string GetPath(ModuleHandle handle)
     return new string(path);
 }
 
+string GetFileName(ModuleHandle handle)
+{
+    TargetPointer fileNameStart = target.ReadPointer(handle.Address + /* Module::FileName offset */);
+    char[] fileName = // Read<char> from target starting at fileNameStart until null terminator
+    return new string(fileName);
+}
+
 TargetPointer GetLoaderAllocator(ModuleHandle handle)
 {
     return target.ReadPointer(handle.Address + /* Module::LoaderAllocator offset */);

src/coreclr/debug/runtimeinfo/datadescriptor.h

@@ -221,11 +221,12 @@ CDAC_TYPE_BEGIN(Module)
 CDAC_TYPE_INDETERMINATE(Module)
 CDAC_TYPE_FIELD(Module, /*pointer*/, Assembly, cdac_data<Module>::Assembly)
 CDAC_TYPE_FIELD(Module, /*pointer*/, Base, cdac_data<Module>::Base)
-CDAC_TYPE_FIELD(Module, /*pointer*/, Flags, cdac_data<Module>::Flags)
+CDAC_TYPE_FIELD(Module, /*uint32*/, Flags, cdac_data<Module>::Flags)
 CDAC_TYPE_FIELD(Module, /*pointer*/, LoaderAllocator, cdac_data<Module>::LoaderAllocator)
 CDAC_TYPE_FIELD(Module, /*pointer*/, ThunkHeap, cdac_data<Module>::ThunkHeap)
 CDAC_TYPE_FIELD(Module, /*pointer*/, DynamicMetadata, cdac_data<Module>::DynamicMetadata)
 CDAC_TYPE_FIELD(Module, /*pointer*/, Path, cdac_data<Module>::Path)
+CDAC_TYPE_FIELD(Module, /*pointer*/, FileName, cdac_data<Module>::FileName)
 
 CDAC_TYPE_FIELD(Module, /*pointer*/, FieldDefToDescMap, cdac_data<Module>::FieldDefToDescMap)
 CDAC_TYPE_FIELD(Module, /*pointer*/, ManifestModuleReferencesMap, cdac_data<Module>::ManifestModuleReferencesMap)

src/coreclr/vm/ceeload.cpp

@@ -416,6 +416,7 @@ void Module::Initialize(AllocMemTracker *pamTracker, LPCWSTR szName)
     m_loaderAllocator = GetAssembly()->GetLoaderAllocator();
     m_pSimpleName = m_pPEAssembly->GetSimpleName();
     m_path = m_pPEAssembly->GetPath().GetUnicode();
+    m_fileName = m_pPEAssembly->GetModuleFileNameHint();
     _ASSERTE(m_path != NULL);
     m_baseAddress = m_pPEAssembly->HasLoadedPEImage() ? m_pPEAssembly->GetLoadedLayout()->GetBase() : NULL;
     if (m_pPEAssembly->IsReflectionEmit())

src/coreclr/vm/ceeload.h

@@ -608,8 +608,9 @@ class Module : public ModuleBase
     VPTR_VTABLE_CLASS(Module, ModuleBase)
 
 private:
-    PTR_CUTF8               m_pSimpleName; // Cached simple name for better performance and easier diagnostics
-    const WCHAR*            m_path;        // Cached path for easier diagnostics
+    PTR_CUTF8               m_pSimpleName;  // Cached simple name for better performance and easier diagnostics
+    const WCHAR*            m_path;         // Cached path for easier diagnostics
+    const WCHAR*            m_fileName;     // Cached file name for easier diagnostics
 
     PTR_PEAssembly          m_pPEAssembly;
     PTR_VOID                m_baseAddress; // Cached base address for easier diagnostics
@@ -1647,6 +1648,7 @@ struct cdac_data<Module>
     static constexpr size_t ThunkHeap = offsetof(Module, m_pThunkHeap);
     static constexpr size_t DynamicMetadata = offsetof(Module, m_pDynamicMetadata);
     static constexpr size_t Path = offsetof(Module, m_path);
+    static constexpr size_t FileName = offsetof(Module, m_fileName);
 
     // Lookup map pointers
     static constexpr size_t FieldDefToDescMap = offsetof(Module, m_FieldDefToDescMap);

src/coreclr/vm/peassembly.h

@@ -116,10 +116,11 @@ class PEAssembly final
     const SString& GetPath();
     const SString& GetIdentityPath();
 
-#ifdef DACCESS_COMPILE
-    // This is the metadata module name. Used as a hint as file name.
+    // This is the module file name. Used as a hint as file name.
+    // For assemblies loaded from a path or single-file bundle, this is the file name portion of the path
+    // For assemblies loaded from memory, this is the module file name from metadata
+    // For reflection emitted assemblies, this is an empty string
     const SString &GetModuleFileNameHint();
-#endif // DACCESS_COMPILE
 
     LPCWSTR GetPathForErrorMessages();
 

src/coreclr/vm/peassembly.inl

@@ -182,7 +182,6 @@ inline const SString& PEAssembly::GetIdentityPath()
     return m_PEImage->GetPath();
 }
 
-#ifdef DACCESS_COMPILE
 inline const SString &PEAssembly::GetModuleFileNameHint()
 {
     CONTRACTL
@@ -201,7 +200,6 @@ inline const SString &PEAssembly::GetModuleFileNameHint()
     else
         return m_PEImage->GetModuleFileNameHintForDAC();
 }
-#endif // DACCESS_COMPILE
 
 #ifdef LOGGING
 inline LPCUTF8 PEAssembly::GetDebugName()

src/coreclr/vm/peimage.cpp

@@ -536,10 +536,11 @@ void PEImage::EnumMemoryRegions(CLRDataEnumMemoryFlags flags)
     // these necessary fields enumerated no matter what.
     m_path.EnumMemoryRegions(flags);
 
-    // We always want this field in mini/triage/heap dumps.
+    // SString skips enumeration for triage dumps, but we always want this field, so we specify
+    // CLRDATA_ENUM_MEM_DEFAULT as the flags. This value is used in cases where we either can't
+    // use the full path (triage dumps) or don't have a path (in-memory assembly)
     m_sModuleFileNameHintUsedByDac.EnumMemoryRegions(CLRDATA_ENUM_MEM_DEFAULT);
 
-
     EX_TRY
     {
         if (HasLoadedLayout() && HasNTHeaders() && HasDirectoryEntry(IMAGE_DIRECTORY_ENTRY_DEBUG))

src/coreclr/vm/peimage.h

@@ -182,8 +182,8 @@ class PEImage final
     void SetModuleFileNameHintForDAC();
 #ifdef DACCESS_COMPILE
     void EnumMemoryRegions(CLRDataEnumMemoryFlags flags);
-    const SString &GetModuleFileNameHintForDAC();
 #endif
+    const SString &GetModuleFileNameHintForDAC();
 
 private:
 #ifndef DACCESS_COMPILE
@@ -302,12 +302,10 @@ class PEImage final
     DWORD m_dwPEKind;
     DWORD m_dwMachine;
 
-    // This variable will have the data of module name.
-    // It is only used by DAC to remap fusion loaded modules back to
-    // disk IL. This really is a workaround. The real fix is for fusion loader
-    // hook (public API on hosting) to take an additional file name hint.
-    // We are piggy backing on the fact that module name is the same as file name!!!
-    SString   m_sModuleFileNameHintUsedByDac; // This is only used by DAC
+    // This only used by DAC
+    // For assemblies loaded from a path or single-file bundle, this is the file name portion of the path
+    // For assemblies loaded from memory, this is the module file name from metadata
+    SString   m_sModuleFileNameHintUsedByDac;
 
     enum
     {

src/coreclr/vm/peimage.inl

@@ -88,16 +88,12 @@ inline void PEImage::SetModuleFileNameHintForDAC()
     }
 }
 
-#ifdef DACCESS_COMPILE
 inline const SString &PEImage::GetModuleFileNameHintForDAC()
 {
     LIMITED_METHOD_CONTRACT;
 
     return m_sModuleFileNameHintUsedByDac;
 }
-#endif
-
-
 
 inline BOOL PEImage::IsFile()
 {

src/native/managed/cdacreader/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/ILoader.cs

@@ -41,6 +41,7 @@ internal interface ILoader : IContract
     public virtual TargetPointer GetAssembly(ModuleHandle handle) => throw new NotImplementedException();
     public virtual ModuleFlags GetFlags(ModuleHandle handle) => throw new NotImplementedException();
     public virtual string GetPath(ModuleHandle handle) => throw new NotImplementedException();
+    public virtual string GetFileName(ModuleHandle handle) => throw new NotImplementedException();
 
     public virtual TargetPointer GetLoaderAllocator(ModuleHandle handle) => throw new NotImplementedException();
     public virtual TargetPointer GetThunkHeap(ModuleHandle handle) => throw new NotImplementedException();

src/native/managed/cdacreader/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/Loader_1.cs

@@ -37,7 +37,17 @@ ModuleFlags ILoader.GetFlags(ModuleHandle handle)
     string ILoader.GetPath(ModuleHandle handle)
     {
         Data.Module module = _target.ProcessedData.GetOrAdd<Data.Module>(handle.Address);
-        return _target.ReadUtf16String(module.Path);
+        return module.Path != TargetPointer.Null
+            ? _target.ReadUtf16String(module.Path)
+            : string.Empty;
+    }
+
+    string ILoader.GetFileName(ModuleHandle handle)
+    {
+        Data.Module module = _target.ProcessedData.GetOrAdd<Data.Module>(handle.Address);
+        return module.FileName != TargetPointer.Null
+            ? _target.ReadUtf16String(module.FileName)
+            : string.Empty;
     }
 
     TargetPointer ILoader.GetLoaderAllocator(ModuleHandle handle)

src/native/managed/cdacreader/Microsoft.Diagnostics.DataContractReader.Contracts/Data/Module.cs

@@ -24,6 +24,7 @@ public Module(Target target, TargetPointer address)
         ThunkHeap = target.ReadPointer(address + (ulong)type.Fields[nameof(ThunkHeap)].Offset);
         DynamicMetadata = target.ReadPointer(address + (ulong)type.Fields[nameof(DynamicMetadata)].Offset);
         Path = target.ReadPointer(address + (ulong)type.Fields[nameof(Path)].Offset);
+        FileName = target.ReadPointer(address + (ulong)type.Fields[nameof(FileName)].Offset);
 
         FieldDefToDescMap = address + (ulong)type.Fields[nameof(FieldDefToDescMap)].Offset;
         ManifestModuleReferencesMap = address + (ulong)type.Fields[nameof(ManifestModuleReferencesMap)].Offset;
@@ -41,6 +42,7 @@ public Module(Target target, TargetPointer address)
     public TargetPointer ThunkHeap { get; init; }
     public TargetPointer DynamicMetadata { get; init; }
     public TargetPointer Path { get; init; }
+    public TargetPointer FileName { get; init; }
 
     public TargetPointer FieldDefToDescMap { get; init; }
     public TargetPointer ManifestModuleReferencesMap { get; init; }