Add the allocsize attribute to LLVM.

`allocsize` is a function attribute that allows users to request that
LLVM treat arbitrary functions as allocation functions.

This patch makes LLVM accept the `allocsize` attribute, and makes
`@llvm.objectsize` recognize said attribute.

The review for this was split into two patches for ease of reviewing:
D18974 and D14933. As promised on the revisions, I'm landing both
patches as a single commit.

Differential Revision: http://reviews.llvm.org/D14933


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266032 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/IR/AttributeImpl.h b/lib/IR/AttributeImpl.h
index 33250433988..7b4b3bb18e7 100644
--- a/lib/IR/AttributeImpl.h
+++ b/lib/IR/AttributeImpl.h
@@ -17,6 +17,7 @@
 #define LLVM_LIB_IR_ATTRIBUTEIMPL_H
 
 #include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/TrailingObjects.h"
@@ -120,7 +121,8 @@ public:
       : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) {
     assert((Kind == Attribute::Alignment || Kind == Attribute::StackAlignment ||
             Kind == Attribute::Dereferenceable ||
-            Kind == Attribute::DereferenceableOrNull) &&
+            Kind == Attribute::DereferenceableOrNull ||
+            Kind == Attribute::AllocSize) &&
            "Wrong kind for int attribute!");
   }
 
@@ -188,6 +190,7 @@ public:
   unsigned getStackAlignment() const;
   uint64_t getDereferenceableBytes() const;
   uint64_t getDereferenceableOrNullBytes() const;
+  std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
   std::string getAsString(bool InAttrGrp) const;
 
   typedef const Attribute *iterator;