[llvm] r259942 - More workarounds for undefined behavior exposed when compiling in C++14 with

Richard Smith via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 5 14:32:52 PST 2016


Author: rsmith
Date: Fri Feb  5 16:32:52 2016
New Revision: 259942

URL: http://llvm.org/viewvc/llvm-project?rev=259942&view=rev
Log:
More workarounds for undefined behavior exposed when compiling in C++14 with
-fsized-deallocation. Disable sized deallocation for all objects derived from
TrailingObjects, as we expect the storage allocated for these objects to be
larger than the size of their dynamic type.

Modified:
    llvm/trunk/include/llvm/Support/TrailingObjects.h
    llvm/trunk/lib/IR/AttributeImpl.h
    llvm/trunk/unittests/Support/TrailingObjectsTest.cpp

Modified: llvm/trunk/include/llvm/Support/TrailingObjects.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/TrailingObjects.h?rev=259942&r1=259941&r2=259942&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/TrailingObjects.h (original)
+++ llvm/trunk/include/llvm/Support/TrailingObjects.h Fri Feb  5 16:32:52 2016
@@ -79,6 +79,11 @@ public:
 
 /// The base class for TrailingObjects* classes.
 class TrailingObjectsBase {
+public:
+  /// Disable sized deallocation for all objects with trailing object storage;
+  /// the inferred size will typically not be correct.
+  void operator delete(void *P) { return ::operator delete(P); }
+
 protected:
   /// OverloadToken's purpose is to allow specifying function overloads
   /// for different types, without actually taking the types as
@@ -290,7 +295,8 @@ class TrailingObjects : private trailing
   }
 
 public:
-  // make this (privately inherited) class public.
+  // Make these (privately inherited) members public.
+  using ParentType::operator delete;
   using ParentType::OverloadToken;
 
   /// Returns a pointer to the trailing object array of the given type

Modified: llvm/trunk/lib/IR/AttributeImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/AttributeImpl.h?rev=259942&r1=259941&r2=259942&view=diff
==============================================================================
--- llvm/trunk/lib/IR/AttributeImpl.h (original)
+++ llvm/trunk/lib/IR/AttributeImpl.h Fri Feb  5 16:32:52 2016
@@ -171,6 +171,8 @@ class AttributeSetNode final
   void operator=(const AttributeSetNode &) = delete;
   AttributeSetNode(const AttributeSetNode &) = delete;
 public:
+  using TrailingObjects::operator delete;
+
   static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
 
   bool hasAttribute(Attribute::AttrKind Kind) const {
@@ -266,6 +268,8 @@ public:
     }
   }
 
+  using TrailingObjects::operator delete;
+
   /// \brief Get the context that created this AttributeSetImpl.
   LLVMContext &getContext() { return Context; }
 

Modified: llvm/trunk/unittests/Support/TrailingObjectsTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/TrailingObjectsTest.cpp?rev=259942&r1=259941&r2=259942&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/TrailingObjectsTest.cpp (original)
+++ llvm/trunk/unittests/Support/TrailingObjectsTest.cpp Fri Feb  5 16:32:52 2016
@@ -34,6 +34,7 @@ public:
     void *Mem = ::operator new(totalSizeToAlloc<short>(NumShorts));
     return new (Mem) Class1(ShortArray, NumShorts);
   }
+  using TrailingObjects::operator delete;
 
   short get(unsigned Num) const { return getTrailingObjects<short>()[Num]; }
 
@@ -78,6 +79,7 @@ public:
       *C->getTrailingObjects<double>() = D;
     return C;
   }
+  using TrailingObjects::operator delete;
 
   short getShort() const {
     if (!HasShort)




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