New file, for use by the pool allocator project

llvm-svn: 9702

include/Support/MallocAllocator.h

@@ -0,0 +1,68 @@
+//===-- Support/MallocAllocator.h - Allocator using malloc/free -*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file defines MallocAllocator class, an STL compatible allocator which
+// just uses malloc/free to get and release memory.  The default allocator uses
+// the STL pool allocator runtime library, this explicitly avoids it.
+//
+// This file is used for variety of purposes, including the pool allocator
+// project and testing, regardless of whether or not it's used directly in the
+// LLVM code, so don't delete this from CVS if you think it's unused!
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_MALLOCALLOCATOR_H
+#define SUPPORT_MALLOCALLOCATOR_H
+
+#include <cstdlib>
+#include <memory>
+
+template<typename T>
+struct MallocAllocator {
+  typedef size_t size_type;
+  typedef ptrdiff_t difference_type;
+  typedef T* pointer;
+  typedef const T* const_pointer;
+  typedef T& reference;
+  typedef const T& const_reference;
+  typedef T value_type;
+  template <class U> struct rebind {
+    typedef MallocAllocator<U> other;
+  };
+
+  pointer address(reference x) const { return &x; }
+  const_pointer address(const_reference x) const { return &x; }
+  size_type max_size() const { return ~0 / sizeof(T); }
+  
+  pointer allocate(size_t n, void* hint = 0) {
+    return (pointer)malloc(n*sizeof(T));
+  }
+
+  void deallocate(pointer p, size_t n) {
+    free((void*)p);
+  }
+
+  void construct(pointer p, const T &val) {
+    new((void*)p) T(val);
+  }
+  void destroy(pointer p) {
+    p->~T();
+  }
+};
+
+template<typename T>
+inline bool operator==(const MallocAllocator<T> &, const MallocAllocator<T> &) {
+  return true;
+}
+template<typename T>
+inline bool operator!=(const MallocAllocator<T>&, const MallocAllocator<T>&) {
+  return false;
+}
+
+#endif