Replace a destructor of EHCleanupScope with a Destroy() method to reflect the current usage.

[kcc]

Summary

The current code uses memset to re-initialize EHCleanupScope objects
with breaks the assumptions of the upcoming asan's intra-object-overflow checker.
If there is no DTOR, the new checker will refuse to work.

[rnk]

lgtm

lib/CodeGen/CGCleanup.h

287

This needs LLVM_DELETED_FUNCTION due to MSVC 2012.

[kcc]

use LLVM_DELETED_FUNCTION

lib/CodeGen/CGCleanup.h

EHCleanupScope(bool isNormal, bool isEH, bool isActive,
     CleanupBits.TestFlagInNormalCleanup = false;
     CleanupBits.TestFlagInEHCleanup = false;
     CleanupBits.CleanupSize = cleanupSize;
     CleanupBits.FixupDepth = fixupDepth;
 
     assert(CleanupBits.CleanupSize == cleanupSize && "cleanup size overflow");
   }
 
-  ~EHCleanupScope() {
+  void Destroy() {
     delete ExtInfo;
   }
+  // Objects of EHCleanupScope are not destructed. Use Destroy().
+  ~EHCleanupScope() LLVM_DELETED_FUNCTION;
 
   bool isNormalCleanup() const { return CleanupBits.IsNormalCleanup; }
   llvm::BasicBlock *getNormalBlock() const { return NormalBlock; }
   void setNormalBlock(llvm::BasicBlock *BB) { NormalBlock = BB; }
 
   bool isEHCleanup() const { return CleanupBits.IsEHCleanup; }
   llvm::BasicBlock *getEHBlock() const { return getCachedEHDispatchBlock(); }
   void setEHBlock(llvm::BasicBlock *BB) { setCachedEHDispatchBlock(BB); }

lib/CodeGen/CGCleanup.cpp

void EHScopeStack::popCleanup() {
 
   assert(isa<EHCleanupScope>(*begin()));
   EHCleanupScope &Cleanup = cast<EHCleanupScope>(*begin());
   InnermostNormalCleanup = Cleanup.getEnclosingNormalCleanup();
   InnermostEHScope = Cleanup.getEnclosingEHScope();
   StartOfData += Cleanup.getAllocatedSize();
 
   // Destroy the cleanup.
-  Cleanup.~EHCleanupScope();
+  Cleanup.Destroy();
 
   // Check whether we can shrink the branch-fixups stack.
   if (!BranchFixups.empty()) {
     // If we no longer have any normal cleanups, all the fixups are
     // complete.
     if (!hasNormalCleanups())
       BranchFixups.clear();