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Remove the fallback binder from PEAssembly and AssemblySpec #131894

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Merged
elinor-fung merged 6 commits into from
Aug 8, 2026
Merged

Remove the fallback binder from PEAssembly and AssemblySpec #131894

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96212d7
Remove the redundant fallback binder from AssemblySpec and PEAssembly
elinor-fung Aug 3, 2026
70336dc
Remove AssemblySpec::m_pAppDomain
elinor-fung Aug 5, 2026
e477ca3
Rename GetBinderFromParentAssembly to GetInitialBinder
elinor-fung Aug 5, 2026
7d4bea2
Apply batched suggestions from code review
elinor-fung Aug 5, 2026
743c88b
Update src/coreclr/vm/assemblyspec.cpp
elinor-fung Aug 5, 2026
e4518d1
Normalize line endings in assemblyspec files
elinor-fung Aug 7, 2026
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7 changes: 3 additions & 4 deletions src/coreclr/vm/appdomain.cpp
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Expand Up @@ -3138,7 +3138,6 @@ PEAssembly * AppDomain::BindAssemblySpec(
STATIC_CONTRACT_THROWS;
STATIC_CONTRACT_GC_TRIGGERS;
PRECONDITION(CheckPointer(pSpec));
PRECONDITION(pSpec->GetAppDomain() == this);
PRECONDITION(this==::GetAppDomain());

GCX_PREEMP();
Expand All @@ -3161,7 +3160,7 @@ PEAssembly * AppDomain::BindAssemblySpec(
PEAssembly* result = NULL;
{
ReleaseHolder<BINDER_SPACE::Assembly> boundAssembly;
hrBindResult = pSpec->Bind(this, &boundAssembly, &bindDiagnosticInfo);
hrBindResult = pSpec->Bind(&boundAssembly, &bindDiagnosticInfo);

if (boundAssembly)
{
Expand Down Expand Up @@ -3196,7 +3195,7 @@ PEAssembly * AppDomain::BindAssemblySpec(
if (!pSpec->IsCoreLibSatellite())
{
// Trigger the resolve event also for non-throw situation.
AssemblySpec NewSpec(this);
AssemblySpec NewSpec;
AssemblySpec *pFailedSpec = NULL;

fForceReThrow = TRUE; // Managed resolve event handler can throw
Expand All @@ -3216,7 +3215,7 @@ PEAssembly * AppDomain::BindAssemblySpec(
{
Exception *ex = GET_EXCEPTION();

AssemblySpec NewSpec(this);
AssemblySpec NewSpec;
AssemblySpec *pFailedSpec = NULL;

// Let transient exceptions or managed resolve event handler exceptions propagate
Expand Down
3 changes: 1 addition & 2 deletions src/coreclr/vm/assemblybinder.cpp
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Expand Up @@ -211,10 +211,9 @@ void AssemblyBinder::GetNameForDiagnosticsFromSpec(AssemblySpec* spec, /*out*/ S
{
_ASSERTE(spec != nullptr);

AppDomain* domain = spec->GetAppDomain();
AssemblyBinder* binder = spec->GetBinder();
if (binder == nullptr)
binder = spec->GetBinderFromParentAssembly(domain);
binder = spec->GetInitialBinder();

binder->GetNameForDiagnostics(alcName);
}
Expand Down
12 changes: 2 additions & 10 deletions src/coreclr/vm/assemblynative.cpp
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Expand Up @@ -93,18 +93,10 @@ extern "C" void QCALLTYPE AssemblyNative_InternalLoad(NativeAssemblyNameParts* p
spec.SetParentAssembly(pRefAssembly);

// Have we been passed the reference to the binder against which this load should be triggered?
// If so, then use it to set the fallback load context binder.
// If so, then bind against it instead of the requesting assembly's load context.
if (pBinder != NULL)
{
spec.SetFallbackBinderForRequestingAssembly(pBinder);
spec.SetPreferFallbackBinder();
}
else if (pRefAssembly != NULL)
{
// If the requesting assembly has Fallback LoadContext binder available,
// then set it up in the AssemblySpec.
PEAssembly *pRefAssemblyManifestFile = pRefAssembly->GetPEAssembly();
spec.SetFallbackBinderForRequestingAssembly(pRefAssemblyManifestFile->GetFallbackBinder());
spec.SetExplicitBinder(pBinder);
}

Assembly *pAssembly = spec.LoadAssembly(FILE_LOADED, fThrowOnFileNotFound);
Expand Down
68 changes: 22 additions & 46 deletions src/coreclr/vm/assemblyspec.cpp
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Expand Up @@ -263,58 +263,39 @@ void AssemblySpec::InitializeAssemblyNameRef(_In_ BINDER_SPACE::AssemblyName* as
spec.AssemblyNameInit(assemblyNameRef);
}

AssemblyBinder* AssemblySpec::GetBinderFromParentAssembly(AppDomain *pDomain)
AssemblyBinder* AssemblySpec::GetInitialBinder()
{
CONTRACTL
{
NOTHROW;
GC_NOTRIGGER;
MODE_ANY;
PRECONDITION(pDomain != NULL);
}
CONTRACTL_END;

// If the caller explicitly named the load context to bind against, it wins over the parent's context.
if (GetExplicitBinder() != NULL)
return GetExplicitBinder();

AssemblyBinder *pParentAssemblyBinder = NULL;
Assembly *pParentAssembly = GetParentAssembly();

if(pParentAssembly != NULL)
if (pParentAssembly != NULL)
{
// Get the PEAssembly associated with the parent's assembly
// Get the PEAssembly associated with the parent's assembly. For a dynamic parent this is the
// binder of the assembly that created it, which was captured at Assembly::CreateDynamic time.
PEAssembly *pParentPEAssembly = pParentAssembly->GetPEAssembly();
pParentAssemblyBinder = pParentPEAssembly->GetAssemblyBinder();
}

if (GetPreferFallbackBinder())
{
// If we have been asked to use the fallback load context binder (currently only supported for AssemblyLoadContext.LoadFromAssemblyName),
// then pretend we do not have any binder yet available.
_ASSERTE(GetFallbackBinderForRequestingAssembly() != NULL);
pParentAssemblyBinder = NULL;
}

if (pParentAssemblyBinder == NULL)
{
// If the parent assembly binder is not available, then we maybe dealing with one of the following
// assembly scenarios:
//
// 1) Entrypoint assembly
// 2) AssemblyLoadContext.LoadFromAssemblyName
//
// For (2), we will need to bind against the DefaultContext binder (aka TPA Binder). This happens
// below if we do not find the parent assembly binder.
//
// For (3), fetch the fallback load context binder reference.

pParentAssemblyBinder = GetFallbackBinderForRequestingAssembly();
}

if (!pParentAssemblyBinder)
{
// We can be here when loading assemblies via the host (e.g. ICLRRuntimeHost2::ExecuteAssembly) (see comment above for details).
// We can be here when there is no parent assembly, i.e. the entrypoint assembly, or when loading
// assemblies via the host (e.g. ICLRRuntimeHost2::ExecuteAssembly).
//
// In such a case, the parent assembly (semantically) is CoreLibrary and thus, the default binding context should be
// used as the parent assembly binder.
pParentAssemblyBinder = static_cast<AssemblyBinder*>(pDomain->GetDefaultBinder());
// In such a case, the parent assembly (semantically) is CoreLibrary and thus, the default binding
// context should be used as the parent assembly binder.
pParentAssemblyBinder = AppDomain::GetCurrentDomain()->GetDefaultBinder();
}

return pParentAssemblyBinder;
Expand All @@ -334,7 +315,7 @@ Assembly *AssemblySpec::LoadAssembly(FileLoadLevel targetLevel,
CONTRACTL_END;

ETWOnStartup (LoaderCatchCall_V1, LoaderCatchCallEnd_V1);
AppDomain* pDomain = GetAppDomain();
AppDomain* pDomain = AppDomain::GetCurrentDomain();

Assembly* assembly = pDomain->FindCachedAssembly(this);
if (assembly)
Expand Down Expand Up @@ -581,23 +562,18 @@ AssemblySpecBindingCache::AssemblyBinding* AssemblySpecBindingCache::LookupInter
UPTR key = (UPTR)pSpec->Hash();

AssemblyBinder *pBinderForLookup = NULL;
bool fGetBindingContextFromParent = true;
bool fUsedInitialBinder = false;

// Check if the AssemblySpec already has specified its binding context. This will be set for assemblies that are
// attempted to be explicitly bound using AssemblyLoadContext LoadFrom* methods.
pBinderForLookup = pSpec->GetBinder();

if (pBinderForLookup != NULL)
{
// We are working with the actual binding context in which the assembly was expected to be loaded.
// Thus, we don't need to get it from the parent assembly.
fGetBindingContextFromParent = false;
}

if (fGetBindingContextFromParent)
if (pBinderForLookup == NULL)
{
pBinderForLookup = pSpec->GetBinderFromParentAssembly(pSpec->GetAppDomain());
// No binder is associated with the spec yet, so use the one the bind would start against.
pBinderForLookup = pSpec->GetInitialBinder();
pSpec->SetBinder(pBinderForLookup);
fUsedInitialBinder = true;
}

if (pBinderForLookup)
Expand All @@ -607,9 +583,9 @@ AssemblySpecBindingCache::AssemblyBinding* AssemblySpecBindingCache::LookupInter

AssemblyBinding* pEntry = (AssemblyBinding *)m_map.LookupValue(key, pSpec);

// Reset the binding context if one was originally never present in the AssemblySpec and we didnt find any entry
// Reset the binder if one was originally never present in the AssemblySpec and we didn't find any entry
// in the cache.
if (fGetBindingContextFromParent)
if (fUsedInitialBinder)
{
if (pEntry == (AssemblyBinding *) INVALIDENTRY)
{
Expand Down Expand Up @@ -1009,7 +985,7 @@ BOOL AssemblySpecBindingCache::StoreException(AssemblySpec *pSpec, Exception* pE
pBinderToSaveException = pSpec->GetBinder();
if (pBinderToSaveException == NULL)
{
pBinderToSaveException = pSpec->GetBinderFromParentAssembly(pSpec->GetAppDomain());
pBinderToSaveException = pSpec->GetInitialBinder();
key = key ^ (UPTR)pBinderToSaveException;
}
}
Expand Down
67 changes: 11 additions & 56 deletions src/coreclr/vm/assemblyspec.hpp
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Expand Up @@ -51,14 +51,11 @@ enum NotificationStatus
class AssemblySpec : public BaseAssemblySpec
{
private:
AppDomain *m_pAppDomain;
Assembly *m_pParentAssembly;

// Contains the reference to the fallback load context associated with RefEmitted assembly requesting the load of another assembly (static or dynamic)
AssemblyBinder *m_pFallbackBinder;

// Flag to indicate if we should prefer the fallback load context binder for binding or not.
bool m_fPreferFallbackBinder;
// The initial binder to use when the caller explicitly provided a load context for this load.
// When set, it takes precedence over the binder of the parent assembly as the initial binder.
AssemblyBinder *m_pExplicitBinder;

HRESULT InitializeSpecInternal(mdToken kAssemblyRefOrDef,
IMDInternalImport *pImport,
Expand All @@ -73,32 +70,16 @@ class AssemblySpec : public BaseAssemblySpec

public:

#ifndef DACCESS_COMPILE
AssemblySpec() : m_pAppDomain(::GetAppDomain())
AssemblySpec()
{
LIMITED_METHOD_CONTRACT;
m_pParentAssembly = NULL;

m_pFallbackBinder = NULL;
m_fPreferFallbackBinder = false;

m_pExplicitBinder = NULL;
}
#endif //!DACCESS_COMPILE

AssemblySpec(AppDomain *pAppDomain) : m_pAppDomain(pAppDomain)
{
LIMITED_METHOD_CONTRACT
m_pParentAssembly = NULL;

m_pFallbackBinder = NULL;
m_fPreferFallbackBinder = false;

}


Assembly* GetParentAssembly();

AssemblyBinder* GetBinderFromParentAssembly(AppDomain *pDomain);
AssemblyBinder* GetInitialBinder();

bool HasParentAssembly()
{ WRAPPER_NO_CONTRACT; return GetParentAssembly() != NULL; }
Expand Down Expand Up @@ -139,32 +120,18 @@ class AssemblySpec : public BaseAssemblySpec
m_pParentAssembly = pAssembly;
}

void SetFallbackBinderForRequestingAssembly(AssemblyBinder *pFallbackBinder)
{
LIMITED_METHOD_CONTRACT;

m_pFallbackBinder = pFallbackBinder;
}

AssemblyBinder* GetFallbackBinderForRequestingAssembly()
void SetExplicitBinder(AssemblyBinder *pBinder)
{
LIMITED_METHOD_CONTRACT;

return m_pFallbackBinder;
m_pExplicitBinder = pBinder;
}

void SetPreferFallbackBinder()
AssemblyBinder* GetExplicitBinder()
{
LIMITED_METHOD_CONTRACT;

m_fPreferFallbackBinder = true;
}

bool GetPreferFallbackBinder()
{
LIMITED_METHOD_CONTRACT;

return m_fPreferFallbackBinder;
return m_pExplicitBinder;
}

// Note that this method does not clone the fields!
Expand All @@ -181,10 +148,7 @@ class AssemblySpec : public BaseAssemblySpec
BaseAssemblySpec::CopyFrom(pSource);

SetParentAssembly(pSource->GetParentAssembly());

// Copy the details of the fallback load context binder
SetFallbackBinderForRequestingAssembly(pSource->GetFallbackBinderForRequestingAssembly());
m_fPreferFallbackBinder = pSource->GetPreferFallbackBinder();
SetExplicitBinder(pSource->GetExplicitBinder());
}

HRESULT CheckFriendAssemblyName();
Expand All @@ -193,7 +157,6 @@ class AssemblySpec : public BaseAssemblySpec
mdAssemblyRef *pToken);

HRESULT Bind(
AppDomain* pAppDomain,
BINDER_SPACE::Assembly** ppAssembly,
SString* pDiagnosticInfo = NULL);

Expand All @@ -213,14 +176,6 @@ class AssemblySpec : public BaseAssemblySpec

// Initialize an AssemblyName managed object based on the specified assemblyName
static void InitializeAssemblyNameRef(_In_ BINDER_SPACE::AssemblyName* assemblyName, _Out_ ASSEMBLYNAMEREF* assemblyNameRef);

public:
AppDomain *GetAppDomain()
{
LIMITED_METHOD_CONTRACT;
return m_pAppDomain;
}

};

#define INITIAL_ASM_SPEC_HASH_SIZE 7
Expand Down
6 changes: 2 additions & 4 deletions src/coreclr/vm/coreassemblyspec.cpp
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Expand Up @@ -26,22 +26,20 @@
#include "../binder/inc/assemblybindercommon.hpp"
#include "../binder/inc/applicationcontext.hpp"

HRESULT AssemblySpec::Bind(AppDomain *pAppDomain, BINDER_SPACE::Assembly** ppAssembly, SString* pDiagnosticInfo)
HRESULT AssemblySpec::Bind(BINDER_SPACE::Assembly** ppAssembly, SString* pDiagnosticInfo)
{
CONTRACTL
{
INSTANCE_CHECK;
STANDARD_VM_CHECK;
PRECONDITION(CheckPointer(ppAssembly));
PRECONDITION(CheckPointer(pAppDomain));
PRECONDITION(IsCoreLib() == FALSE); // This should never be called for CoreLib (explicit loading)
}
CONTRACTL_END;

HRESULT hr=S_OK;

// Have a default binding context setup
AssemblyBinder *pBinder = GetBinderFromParentAssembly(pAppDomain);
AssemblyBinder *pBinder = GetInitialBinder();

ReleaseHolder<BINDER_SPACE::Assembly> pPrivAsm;
_ASSERTE(pBinder != NULL);
Expand Down
10 changes: 5 additions & 5 deletions src/coreclr/vm/peassembly.cpp
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Expand Up @@ -642,7 +642,7 @@ PEAssembly::PEAssembly(
BINDER_SPACE::Assembly* pBindResultInfo,
IMetaDataEmit* pEmit,
BOOL isSystem,
AssemblyBinder* pFallbackBinder /*= NULL*/,
AssemblyBinder* pDynamicAssemblyBinder /*= NULL*/,
PEImage * pPEImage /*= NULL*/,
BINDER_SPACE::Assembly * pHostAssembly /*= NULL*/)
{
Expand Down Expand Up @@ -723,7 +723,7 @@ PEAssembly::PEAssembly(
}
else
{
m_pAssemblyBinder = pFallbackBinder;
m_pAssemblyBinder = pDynamicAssemblyBinder;
}

#ifdef LOGGING
Expand All @@ -744,7 +744,7 @@ PEAssembly *PEAssembly::Open(
nullptr, // BindResult
nullptr, // IMetaDataEmit
FALSE, // isSystem
nullptr, // FallbackBinder
nullptr, // DynamicAssemblyBinder
pPEImageIL,
pHostAssembly);

Expand Down Expand Up @@ -837,7 +837,7 @@ PEAssembly* PEAssembly::Open(BINDER_SPACE::Assembly* pBindResult)
};

/* static */
PEAssembly *PEAssembly::Create(IMetaDataAssemblyEmit *pAssemblyEmit, AssemblyBinder *pFallbackBinder)
PEAssembly *PEAssembly::Create(IMetaDataAssemblyEmit *pAssemblyEmit, AssemblyBinder *pDynamicAssemblyBinder)
{
CONTRACTL
{
Expand All @@ -850,7 +850,7 @@ PEAssembly *PEAssembly::Create(IMetaDataAssemblyEmit *pAssemblyEmit, AssemblyBin
// we have.)
ReleaseHolder<IMetaDataEmit> pEmit;
pAssemblyEmit->QueryInterface(IID_IMetaDataEmit, (void **)&pEmit);
return new PEAssembly(NULL, pEmit, FALSE, pFallbackBinder);
return new PEAssembly(NULL, pEmit, FALSE, pDynamicAssemblyBinder);
}

#endif // #ifndef DACCESS_COMPILE
Expand Down
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