[clang] 1c0063b - [clang][Interp] Remove StoragKind limitation in Pointer assign operators

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2024-06-07T10:32:16+02:00
New Revision: 1c0063b58a4fc23c94c7f5bf5a937bbdf9703cc0

URL: https://github.com/llvm/llvm-project/commit/1c0063b58a4fc23c94c7f5bf5a937bbdf9703cc0
DIFF: https://github.com/llvm/llvm-project/commit/1c0063b58a4fc23c94c7f5bf5a937bbdf9703cc0.diff

LOG: [clang][Interp] Remove StoragKind limitation in Pointer assign operators

It's not strictly needed and did cause some test failures.

Added: 
    

Modified: 
    clang/lib/AST/Interp/Pointer.cpp
    clang/test/AST/Interp/cxx20.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/Pointer.cpp b/clang/lib/AST/Interp/Pointer.cpp
index a60b4d28b4387..e3d21f93f114e 100644
--- a/clang/lib/AST/Interp/Pointer.cpp
+++ b/clang/lib/AST/Interp/Pointer.cpp
@@ -64,26 +64,26 @@ Pointer::~Pointer() {
 }
 
 void Pointer::operator=(const Pointer &P) {
-  if (!this->isIntegralPointer() || !P.isBlockPointer())
-    assert(P.StorageKind == StorageKind || (this->isZero() && P.isZero()));
-
+  // If the current storage type is Block, we need to remove
+  // this pointer from the block.
   bool WasBlockPointer = isBlockPointer();
-  StorageKind = P.StorageKind;
   if (StorageKind == Storage::Block) {
     Block *Old = PointeeStorage.BS.Pointee;
-    if (WasBlockPointer && PointeeStorage.BS.Pointee)
+    if (WasBlockPointer && Old) {
       PointeeStorage.BS.Pointee->removePointer(this);
+      Old->cleanup();
+    }
+  }
 
-    Offset = P.Offset;
+  StorageKind = P.StorageKind;
+  Offset = P.Offset;
+
+  if (P.isBlockPointer()) {
     PointeeStorage.BS = P.PointeeStorage.BS;
 
     if (PointeeStorage.BS.Pointee)
       PointeeStorage.BS.Pointee->addPointer(this);
-
-    if (WasBlockPointer && Old)
-      Old->cleanup();
-
-  } else if (StorageKind == Storage::Int) {
+  } else if (P.isIntegralPointer()) {
     PointeeStorage.Int = P.PointeeStorage.Int;
   } else {
     assert(false && "Unhandled storage kind");
@@ -91,26 +91,26 @@ void Pointer::operator=(const Pointer &P) {
 }
 
 void Pointer::operator=(Pointer &&P) {
-  if (!this->isIntegralPointer() || !P.isBlockPointer())
-    assert(P.StorageKind == StorageKind || (this->isZero() && P.isZero()));
-
+  // If the current storage type is Block, we need to remove
+  // this pointer from the block.
   bool WasBlockPointer = isBlockPointer();
-  StorageKind = P.StorageKind;
   if (StorageKind == Storage::Block) {
     Block *Old = PointeeStorage.BS.Pointee;
-    if (WasBlockPointer && PointeeStorage.BS.Pointee)
+    if (WasBlockPointer && Old) {
       PointeeStorage.BS.Pointee->removePointer(this);
+      Old->cleanup();
+    }
+  }
 
-    Offset = P.Offset;
+  StorageKind = P.StorageKind;
+  Offset = P.Offset;
+
+  if (P.isBlockPointer()) {
     PointeeStorage.BS = P.PointeeStorage.BS;
 
     if (PointeeStorage.BS.Pointee)
       PointeeStorage.BS.Pointee->addPointer(this);
-
-    if (WasBlockPointer && Old)
-      Old->cleanup();
-
-  } else if (StorageKind == Storage::Int) {
+  } else if (P.isIntegralPointer()) {
     PointeeStorage.Int = P.PointeeStorage.Int;
   } else {
     assert(false && "Unhandled storage kind");

diff  --git a/clang/test/AST/Interp/cxx20.cpp b/clang/test/AST/Interp/cxx20.cpp
index 49ee040be392e..c750be866ca7c 100644
--- a/clang/test/AST/Interp/cxx20.cpp
+++ b/clang/test/AST/Interp/cxx20.cpp
@@ -782,3 +782,18 @@ namespace APValues {
   constexpr const A &v = get<A{}>;
   constexpr const A &w = get<A{1, &g, &A::n, "hello"}>;
 }
+
+namespace self_referencing {
+  struct S {
+    S* ptr = nullptr;
+    constexpr S(int i) : ptr(this) {
+      if (this == ptr && i)
+        ptr = nullptr;
+    }
+    constexpr ~S() {}
+  };
+
+  void test() {
+    S s(1);
+  }
+}