Handle C++ delete expressions when the overloaded delete operator is a

"usual deallocation function" with two arguments. CodeGen will have to
handle this case specifically, since the value for the second argument
(the size of the allocated object) may have to be computed at run
time.

Fixes the Sema part of PR4782.

llvm-svn: 83080

1 files changed, 34 insertions, 0 deletions

diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index fc04ed401bf..d1aef6a5b34 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -451,6 +451,40 @@ CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD,
                                isStatic, isInline);
 }
 
+bool CXXMethodDecl::isUsualDeallocationFunction() const {
+  if (getOverloadedOperator() != OO_Delete &&
+      getOverloadedOperator() != OO_Array_Delete)
+    return false;
+  
+  // C++ [basic.stc.dynamic.deallocation]p2:
+  //   If a class T has a member deallocation function named operator delete 
+  //   with exactly one parameter, then that function is a usual (non-placement)
+  //   deallocation function. [...]
+  if (getNumParams() == 1)
+    return true;
+  
+  // C++ [basic.stc.dynamic.deallocation]p2:
+  //   [...] If class T does not declare such an operator delete but does 
+  //   declare a member deallocation function named operator delete with 
+  //   exactly two parameters, the second of which has type std::size_t (18.1),
+  //   then this function is a usual deallocation function.
+  ASTContext &Context = getASTContext();
+  if (getNumParams() != 2 ||
+      !Context.hasSameType(getParamDecl(1)->getType(), Context.getSizeType()))
+    return false;
+                 
+  // This function is a usual deallocation function if there are no 
+  // single-parameter deallocation functions of the same kind.
+  for (DeclContext::lookup_const_result R = getDeclContext()->lookup(getDeclName());
+       R.first != R.second; ++R.first) {
+    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*R.first))
+      if (FD->getNumParams() == 1)
+        return false;
+  }
+  
+  return true;
+}
+
 typedef llvm::DenseMap<const CXXMethodDecl*,
                        std::vector<const CXXMethodDecl *> *>
                        OverriddenMethodsMapTy;