[clang] 4c367b4 - [clang][bytecode] Remove double pointer type checks in Load{,Pop} (#225802)

[via cfe-commits]

Author: Timm Baeder
Date: 2026-09-24T07:20:49+02:00
New Revision: 4c367b4ff3cf60fe5fb8e7eba02ed0b42b9e40ab

URL: https://github.com/llvm/llvm-project/commit/4c367b4ff3cf60fe5fb8e7eba02ed0b42b9e40ab
DIFF: https://github.com/llvm/llvm-project/commit/4c367b4ff3cf60fe5fb8e7eba02ed0b42b9e40ab.diff

LOG: [clang][bytecode] Remove double pointer type checks in Load{,Pop} (#225802)

Make sure that `CheckLoad` only returns true if the load is actually
valid.

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Interp.cpp
    clang/lib/AST/ByteCode/Interp.h
    clang/lib/AST/ByteCode/InterpHelpers.h

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index b0c4c9b66c308..f885c0dc9cdb2 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -1052,7 +1052,7 @@ bool CheckLoad(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
 
   // Block and string pointers are the only ones we can actually read from.
   if (!Ptr.isReadablePointerType())
-    return CheckDummy(S, OpPC, Ptr, AK);
+    return diagnoseDummy(S, OpPC, Ptr, AK);
 
   assert(Ptr.isStringPointer());
 
@@ -1070,7 +1070,7 @@ bool CheckLoad(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
 bool CheckFinalLoad(InterpState &S, CodePtr OpPC, const Pointer &Ptr) {
   assert(!Ptr.isZero());
   if (!Ptr.isReadablePointerType())
-    return CheckDummy(S, OpPC, Ptr, AK_Read);
+    return diagnoseDummy(S, OpPC, Ptr, AK_Read);
 
   if (Ptr.isBlockPointer() && !Ptr.block()->isAccessible()) {
     if (!CheckLive(S, OpPC, Ptr, AK_Read))
@@ -1107,7 +1107,7 @@ bool CheckStore(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
     return false;
 
   if (Ptr.isOpaquePointer())
-    return CheckDummy(S, OpPC, Ptr, AK);
+    return diagnoseDummy(S, OpPC, Ptr, AK);
 
   if (!Ptr.isBlockPointer())
     return false;
@@ -1428,11 +1428,8 @@ bool InvalidDeclRef(InterpState &S, CodePtr OpPC, const DeclRefExpr *DR,
   return CheckDeclRef(S, OpPC, DR);
 }
 
-bool CheckDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
-                AccessKinds AK) {
-  if (!Ptr.isDummy())
-    return true;
-
+bool diagnoseDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
+                   AccessKinds AK) {
   if (!S.diagnosing())
     return false;
 
@@ -1448,6 +1445,13 @@ bool CheckDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
   return false;
 }
 
+bool CheckDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
+                AccessKinds AK) {
+  if (!Ptr.isDummy())
+    return true;
+  return diagnoseDummy(S, OpPC, Ptr, AK);
+}
+
 static bool CheckNonNullArgs(InterpState &S, CodePtr OpPC, const Function *F,
                              const CallExpr *CE, unsigned ArgSize) {
   auto Args = ArrayRef(CE->getArgs(), CE->getNumArgs());
@@ -2839,8 +2843,10 @@ bool CheckNewTypeMismatch(InterpState &S, CodePtr OpPC, const Expr *E,
     return false;
   }
 
+  if (Ptr.isDummy())
+    return diagnoseDummy(S, OpPC, Ptr, AK_Construct);
   if (!Ptr.isBlockPointer())
-    return CheckDummy(S, OpPC, Ptr, AK_Construct);
+    return false;
 
   if (!CheckRange(S, OpPC, Ptr, AK_Construct))
     return false;
@@ -2854,7 +2860,7 @@ bool CheckNewTypeMismatch(InterpState &S, CodePtr OpPC, const Expr *E,
       return false;
     if (!CheckLive(S, OpPC, Ptr, AK_Construct))
       return false;
-    return CheckDummy(S, OpPC, Ptr, AK_Construct);
+    return diagnoseDummy(S, OpPC, Ptr, AK_Construct);
   }
   if (!CheckTemporary(S, OpPC, Ptr, AK_Construct))
     return false;

diff  --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h
index aec352bc08b32..14988eb9acb53 100644
--- a/clang/lib/AST/ByteCode/Interp.h
+++ b/clang/lib/AST/ByteCode/Interp.h
@@ -2220,8 +2220,6 @@ bool Load(InterpState &S, CodePtr OpPC) {
   const Pointer &Ptr = S.Stk.peek<Pointer>();
   if (!CheckLoad(S, OpPC, Ptr))
     return false;
-  if (!Ptr.isReadablePointerType())
-    return false;
   if (!Ptr.canDeref(Name))
     return false;
   S.Stk.push<T>(Ptr.load<T>());
@@ -2233,8 +2231,6 @@ bool LoadPop(InterpState &S, CodePtr OpPC) {
   const Pointer &Ptr = S.Stk.pop<Pointer>();
   if (!CheckLoad(S, OpPC, Ptr))
     return false;
-  if (!Ptr.isReadablePointerType())
-    return false;
   if (!Ptr.canDeref(Name))
     return false;
   S.Stk.push<T>(Ptr.load<T>());

diff  --git a/clang/lib/AST/ByteCode/InterpHelpers.h b/clang/lib/AST/ByteCode/InterpHelpers.h
index 38a69b72e0c12..50f0462a93f16 100644
--- a/clang/lib/AST/ByteCode/InterpHelpers.h
+++ b/clang/lib/AST/ByteCode/InterpHelpers.h
@@ -42,6 +42,8 @@ bool CheckLive(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
 /// Checks if a pointer is a dummy pointer.
 bool CheckDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
                 AccessKinds AK);
+bool diagnoseDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
+                   AccessKinds AK);
 
 bool arrayElemPtrOpaque(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
                         APSInt &&Index, bool AllowReplace = true);