Add map of VLA types and their sizes
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60939 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index fe88bc9..bcb51a3 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -401,3 +401,30 @@
return AddrTyped;
}
+llvm::Value *CodeGenFunction::GetVLASize(const VariableArrayType *VAT)
+{
+ llvm::Value *&SizeEntry = VLASizeMap[VAT];
+
+ if (!SizeEntry) {
+ // Get the element size;
+ llvm::Value *ElemSize;
+
+ QualType ElemTy = VAT->getElementType();
+
+ if (const VariableArrayType *ElemVAT =
+ getContext().getAsVariableArrayType(ElemTy))
+ ElemSize = GetVLASize(ElemVAT);
+ else {
+ // FIXME: We use Int32Ty here because the alloca instruction takes a
+ // 32-bit integer. What should we do about overflow?
+ ElemSize = llvm::ConstantInt::get(llvm::Type::Int32Ty,
+ getContext().getTypeSize(ElemTy) / 8);
+ }
+
+ llvm::Value *NumElements = EmitScalarExpr(VAT->getSizeExpr());
+
+ SizeEntry = Builder.CreateMul(ElemSize, NumElements);
+ }
+
+ return SizeEntry;
+}