From 504dfc1b99ef5e9dc30f7d49430196a618052946 Mon Sep 17 00:00:00 2001
From: Aaron R Robinson <arobins@microsoft.com>
Date: Sat, 30 Jul 2022 09:00:07 -0700
Subject: [PATCH 1/2] Remove some undefined behavior

---
 src/coreclr/vm/methodtablebuilder.cpp | 18 +++++++++---------
 src/coreclr/vm/methodtablebuilder.h   |  4 ++--
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/coreclr/vm/methodtablebuilder.cpp b/src/coreclr/vm/methodtablebuilder.cpp
index 74479bf14c2294..9b33eaef6fc64b 100644
--- a/src/coreclr/vm/methodtablebuilder.cpp
+++ b/src/coreclr/vm/methodtablebuilder.cpp
@@ -258,8 +258,8 @@ MethodTableBuilder::LoaderFindMethodInParentClass(
                     // and return the result to the caller.
                     // We do this here to avoid recalculating pSubst.
                     *pMethodConstraintsMatch = MetaSig::CompareMethodConstraints(
-                        &methodSig.GetSubstitution(), methodSig.GetModule(), methodSig.GetToken(),
-                        &entrySig.GetSubstitution(),  entrySig.GetModule(),  entrySig.GetToken());
+                        methodSig.GetSubstitution(), methodSig.GetModule(), methodSig.GetToken(),
+                        entrySig.GetSubstitution(),  entrySig.GetModule(),  entrySig.GetToken());
                 }
 
                 return pEntryMethod;
@@ -869,8 +869,8 @@ MethodTableBuilder::MethodSignature::SignaturesEquivalent(
     STANDARD_VM_CONTRACT;
 
     return !!MetaSig::CompareMethodSigs(
-        sig1.GetSignature(), static_cast<DWORD>(sig1.GetSignatureLength()), sig1.GetModule(), &sig1.GetSubstitution(),
-        sig2.GetSignature(), static_cast<DWORD>(sig2.GetSignatureLength()), sig2.GetModule(), &sig2.GetSubstitution(),
+        sig1.GetSignature(), static_cast<DWORD>(sig1.GetSignatureLength()), sig1.GetModule(), sig1.GetSubstitution(),
+        sig2.GetSignature(), static_cast<DWORD>(sig2.GetSignatureLength()), sig2.GetModule(), sig2.GetSubstitution(),
         allowCovariantReturn);
 }
 
@@ -884,8 +884,8 @@ MethodTableBuilder::MethodSignature::SignaturesExactlyEqual(
 
     TokenPairList newVisited = TokenPairList::AdjustForTypeEquivalenceForbiddenScope(NULL);
     return !!MetaSig::CompareMethodSigs(
-        sig1.GetSignature(), static_cast<DWORD>(sig1.GetSignatureLength()), sig1.GetModule(), &sig1.GetSubstitution(),
-        sig2.GetSignature(), static_cast<DWORD>(sig2.GetSignatureLength()), sig2.GetModule(), &sig2.GetSubstitution(),
+        sig1.GetSignature(), static_cast<DWORD>(sig1.GetSignatureLength()), sig1.GetModule(), sig1.GetSubstitution(),
+        sig2.GetSignature(), static_cast<DWORD>(sig2.GetSignatureLength()), sig2.GetModule(), sig2.GetSubstitution(),
         FALSE, &newVisited);
 }
 
@@ -6257,8 +6257,8 @@ MethodTableBuilder::MethodImplCompareSignatures(
     }
 
     //now compare the method constraints
-    if (!MetaSig::CompareMethodConstraints(&implSig.GetSubstitution(), implSig.GetModule(), implSig.GetToken(),
-                                           &declSig.GetSubstitution(), declSig.GetModule(), declSig.GetToken()))
+    if (!MetaSig::CompareMethodConstraints(implSig.GetSubstitution(), implSig.GetModule(), implSig.GetToken(),
+                                           declSig.GetSubstitution(), declSig.GetModule(), declSig.GetToken()))
     {
         BuildMethodTableThrowException(dwConstraintErrorCode, implSig.GetToken());
     }
@@ -6599,7 +6599,7 @@ VOID MethodTableBuilder::PlaceInterfaceDeclarationOnClass(
     DispatchMapTypeID firstDispatchMapTypeID;
     ComputeDispatchMapTypeIDs(
         pDeclMT,
-        &pDecl->GetMethodSignature().GetSubstitution(),
+        pDecl->GetMethodSignature().GetSubstitution(),
         &firstDispatchMapTypeID,
         1,
         &cInterfaceDuplicates);
diff --git a/src/coreclr/vm/methodtablebuilder.h b/src/coreclr/vm/methodtablebuilder.h
index 1d710db458d497..175fab114b53a7 100644
--- a/src/coreclr/vm/methodtablebuilder.h
+++ b/src/coreclr/vm/methodtablebuilder.h
@@ -783,9 +783,9 @@ class MethodTableBuilder
 
         //-----------------------------------------------------------------------------------------
         // Returns the substitution to be used in interpreting the signature.
-        const Substitution &
+        const Substitution *
         GetSubstitution() const
-            { return *m_pSubst; }
+            { return m_pSubst; }
 
         //-----------------------------------------------------------------------------------------
         // Returns true if the names are equal; otherwise returns false. This is a

From b8ea81e7d17185cfd3cff2f9ead52dc8dfa944bc Mon Sep 17 00:00:00 2001
From: Aaron R Robinson <arobins@microsoft.com>
Date: Sat, 30 Jul 2022 15:46:09 -0700
Subject: [PATCH 2/2] Missed instance under debug build

---
 src/coreclr/vm/methodtablebuilder.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/coreclr/vm/methodtablebuilder.cpp b/src/coreclr/vm/methodtablebuilder.cpp
index 9b33eaef6fc64b..7f623c659c7bb8 100644
--- a/src/coreclr/vm/methodtablebuilder.cpp
+++ b/src/coreclr/vm/methodtablebuilder.cpp
@@ -6622,7 +6622,7 @@ VOID MethodTableBuilder::PlaceInterfaceDeclarationOnClass(
         DispatchMapTypeID * rgDispatchMapTypeIDs = (DispatchMapTypeID *)_alloca(sizeof(DispatchMapTypeID) * cInterfaceDuplicates);
         ComputeDispatchMapTypeIDs(
             pDeclMT,
-            &pDecl->GetMethodSignature().GetSubstitution(),
+            pDecl->GetMethodSignature().GetSubstitution(),
             rgDispatchMapTypeIDs,
             cInterfaceDuplicates,
             &cInterfaceDuplicates);