Patch to ir-gen destruction of array member elements in revers order
of their construction.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@79571 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index 72aa9fc..8b1f2fc 100644
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -412,10 +412,70 @@
EmitBlock(AfterFor, true);
}
+/// EmitCXXAggrDestructorCall - calls the default destructor on array
+/// elements in reverse order of construction.
void
CodeGenFunction::EmitCXXAggrDestructorCall(const CXXDestructorDecl *D,
const ArrayType *Array,
llvm::Value *This) {
+ const ConstantArrayType *CA = dyn_cast<ConstantArrayType>(Array);
+ assert(CA && "Do we support VLA for destruction ?");
+ llvm::Value *One = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext),
+ 1);
+ uint64_t ElementCount = 1;
+ const ConstantArrayType *CAW = CA;
+ do {
+ ElementCount *= CAW->getSize().getZExtValue();
+ CAW = dyn_cast<ConstantArrayType>(CAW->getElementType());
+ } while (CAW);
+ // Create a temporary for the loop index and initialize it with count of
+ // array elements.
+ llvm::Value *IndexPtr = CreateTempAlloca(llvm::Type::getInt64Ty(VMContext),
+ "loop.index");
+ // Index = ElementCount;
+ llvm::Value* UpperCount =
+ llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), ElementCount);
+ Builder.CreateStore(UpperCount, IndexPtr, false);
+
+ // Start the loop with a block that tests the condition.
+ llvm::BasicBlock *CondBlock = createBasicBlock("for.cond");
+ llvm::BasicBlock *AfterFor = createBasicBlock("for.end");
+
+ EmitBlock(CondBlock);
+
+ llvm::BasicBlock *ForBody = createBasicBlock("for.body");
+
+ // Generate: if (loop-index != 0 fall to the loop body,
+ // otherwise, go to the block after the for-loop.
+ llvm::Value* zeroConstant =
+ llvm::Constant::getNullValue(llvm::Type::getInt64Ty(VMContext));
+ llvm::Value *Counter = Builder.CreateLoad(IndexPtr);
+ llvm::Value *IsNE = Builder.CreateICmpNE(Counter, zeroConstant,
+ "isne");
+ // If the condition is true, execute the body.
+ Builder.CreateCondBr(IsNE, ForBody, AfterFor);
+
+ EmitBlock(ForBody);
+
+ llvm::BasicBlock *ContinueBlock = createBasicBlock("for.inc");
+ // Inside the loop body, emit the constructor call on the array element.
+ Counter = Builder.CreateLoad(IndexPtr);
+ Counter = Builder.CreateSub(Counter, One);
+ llvm::Value *Address = Builder.CreateInBoundsGEP(This, Counter, "arrayidx");
+ EmitCXXDestructorCall(D, Dtor_Complete, Address);
+
+ EmitBlock(ContinueBlock);
+
+ // Emit the decrement of the loop counter.
+ Counter = Builder.CreateLoad(IndexPtr);
+ Counter = Builder.CreateSub(Counter, One, "dec");
+ Builder.CreateStore(Counter, IndexPtr, false);
+
+ // Finally, branch back up to the condition for the next iteration.
+ EmitBranch(CondBlock);
+
+ // Emit the fall-through block.
+ EmitBlock(AfterFor, true);
}
void