[clang] a15adf5 - [clang][bytecode][NFC] Add Pointer::stripBaseCasts() helper (#176875)

[via cfe-commits]

Author: Timm Baeder
Date: 2026-01-20T11:21:22+01:00
New Revision: a15adf5b9be33d557c45a5a1cb381f82782e5199

URL: https://github.com/llvm/llvm-project/commit/a15adf5b9be33d557c45a5a1cb381f82782e5199
DIFF: https://github.com/llvm/llvm-project/commit/a15adf5b9be33d557c45a5a1cb381f82782e5199.diff

LOG: [clang][bytecode][NFC] Add Pointer::stripBaseCasts() helper (#176875)

We do this is in a few places, so add a helper function for it.

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Interp.cpp
    clang/lib/AST/ByteCode/Interp.h
    clang/lib/AST/ByteCode/InterpBuiltin.cpp
    clang/lib/AST/ByteCode/Pointer.h

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 0205d840fd71e..768e24c038cda 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -1320,8 +1320,7 @@ bool Free(InterpState &S, CodePtr OpPC, bool DeleteIsArrayForm,
 
     // Remove base casts.
     QualType InitialType = Ptr.getType();
-    while (Ptr.isBaseClass())
-      Ptr = Ptr.getBase();
+    Ptr = Ptr.stripBaseCasts();
 
     Source = Ptr.getDeclDesc()->asExpr();
     BlockToDelete = Ptr.block();
@@ -1709,8 +1708,7 @@ bool Call(InterpState &S, CodePtr OpPC, const Function *Func,
 
 static bool GetDynamicDecl(InterpState &S, CodePtr OpPC, Pointer TypePtr,
                            const CXXRecordDecl *&DynamicDecl) {
-  while (TypePtr.isBaseClass())
-    TypePtr = TypePtr.getBase();
+  TypePtr = TypePtr.stripBaseCasts();
 
   QualType DynamicType = TypePtr.getType();
   if (TypePtr.isStatic() || TypePtr.isConst()) {
@@ -1794,8 +1792,7 @@ bool CallVirt(InterpState &S, CodePtr OpPC, const Function *Func,
       // If the function we call is further DOWN the hierarchy than the
       // FieldDesc of our pointer, just go up the hierarchy of this field
       // the furthest we can go.
-      while (ThisPtr.isBaseClass())
-        ThisPtr = ThisPtr.getBase();
+      ThisPtr = ThisPtr.stripBaseCasts();
     }
   }
 

diff  --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h
index 0eae7848b4fe0..75961126fbce9 100644
--- a/clang/lib/AST/ByteCode/Interp.h
+++ b/clang/lib/AST/ByteCode/Interp.h
@@ -1908,10 +1908,7 @@ inline bool CheckNull(InterpState &S, CodePtr OpPC) {
 
 inline bool VirtBaseHelper(InterpState &S, CodePtr OpPC, const RecordDecl *Decl,
                            const Pointer &Ptr) {
-  Pointer Base = Ptr;
-  while (Base.isBaseClass())
-    Base = Base.getBase();
-
+  Pointer Base = Ptr.stripBaseCasts();
   const Record::Base *VirtBase = Base.getRecord()->getVirtualBase(Decl);
   S.Stk.push<Pointer>(Base.atField(VirtBase->Offset));
   return true;

diff  --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 1b651413f43d7..5d3b6aa77685b 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -1894,13 +1894,8 @@ static bool interp__builtin_memcpy(InterpState &S, CodePtr OpPC,
   // Check for overlapping memory regions.
   if (!Move && Pointer::pointToSameBlock(SrcPtr, DestPtr)) {
     // Remove base casts.
-    Pointer SrcP = SrcPtr;
-    while (SrcP.isBaseClass())
-      SrcP = SrcP.getBase();
-
-    Pointer DestP = DestPtr;
-    while (DestP.isBaseClass())
-      DestP = DestP.getBase();
+    Pointer SrcP = SrcPtr.stripBaseCasts();
+    Pointer DestP = DestPtr.stripBaseCasts();
 
     unsigned SrcIndex = SrcP.expand().getIndex() * SrcP.elemSize();
     unsigned DstIndex = DestP.expand().getIndex() * DestP.elemSize();
@@ -2334,10 +2329,8 @@ static bool interp__builtin_object_size(InterpState &S, CodePtr OpPC,
 
   // The "closest surrounding subobject" is NOT a base class,
   // so strip the base class casts.
-  if (UseFieldDesc && Ptr.isBaseClass()) {
-    while (Ptr.isBaseClass())
-      Ptr = Ptr.getBase();
-  }
+  if (UseFieldDesc && Ptr.isBaseClass())
+    Ptr = Ptr.stripBaseCasts();
 
   const Descriptor *Desc = UseFieldDesc ? Ptr.getFieldDesc() : DeclDesc;
   assert(Desc);

diff  --git a/clang/lib/AST/ByteCode/Pointer.h b/clang/lib/AST/ByteCode/Pointer.h
index 202508cb71e5a..32e1c3268484e 100644
--- a/clang/lib/AST/ByteCode/Pointer.h
+++ b/clang/lib/AST/ByteCode/Pointer.h
@@ -751,6 +751,16 @@ class Pointer {
     getInlineDesc()->LifeState = Lifetime::Started;
   }
 
+  /// Strip base casts from this Pointer.
+  /// The result is either a root pointer or something
+  /// that isn't a base class anymore.
+  [[nodiscard]] Pointer stripBaseCasts() const {
+    Pointer P = *this;
+    while (P.isBaseClass())
+      P = P.getBase();
+    return P;
+  }
+
   /// Compare two pointers.
   ComparisonCategoryResult compare(const Pointer &Other) const {
     if (!hasSameBase(*this, Other))