[clang] [clang][bytecode][NFC] Dead blocks are always uninitialized (PR #152699)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

We always call the descriptor dtor before, so they are never initialized.

---
Full diff: https://github.com/llvm/llvm-project/pull/152699.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/InterpBlock.cpp (+1-2) 
- (modified) clang/lib/AST/ByteCode/InterpState.cpp (+2-4) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/InterpBlock.cpp b/clang/lib/AST/ByteCode/InterpBlock.cpp
index b0e048bc867e9..8b7f6a750040b 100644
--- a/clang/lib/AST/ByteCode/InterpBlock.cpp
+++ b/clang/lib/AST/ByteCode/InterpBlock.cpp
@@ -133,8 +133,7 @@ DeadBlock::DeadBlock(DeadBlock *&Root, Block *Blk)
 }
 
 void DeadBlock::free() {
-  if (B.IsInitialized)
-    B.invokeDtor();
+  assert(!B.isInitialized());
 
   if (Prev)
     Prev->Next = Next;
diff --git a/clang/lib/AST/ByteCode/InterpState.cpp b/clang/lib/AST/ByteCode/InterpState.cpp
index f7f03e593301f..5593531bdabe3 100644
--- a/clang/lib/AST/ByteCode/InterpState.cpp
+++ b/clang/lib/AST/ByteCode/InterpState.cpp
@@ -85,6 +85,7 @@ void InterpState::deallocate(Block *B) {
   if (B->IsInitialized)
     B->invokeDtor();
 
+  assert(!B->isInitialized());
   if (B->hasPointers()) {
     size_t Size = B->getSize();
     // Allocate a new block, transferring over pointers.
@@ -94,10 +95,7 @@ void InterpState::deallocate(Block *B) {
     // Since the block doesn't hold any actual data anymore, we can just
     // memcpy() everything over.
     std::memcpy(D->rawData(), B->rawData(), B->getSize());
-    D->B.IsInitialized = B->IsInitialized;
-
-    // We moved the contents over to the DeadBlock.
-    B->IsInitialized = false;
+    D->B.IsInitialized = false;
   }
 }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/152699