From a4d9869cf291e6f87bf9e7adfcd9a2c4e4518172 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Wed, 17 Oct 2007 20:56:47 +0000
Subject: [PATCH] Added llvm::AlignOf, a template class whose purpose is to
portably compute the minimum memory alignment of arbitrary types.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43086 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/llvm/Support/AlignOf.h | 43 ++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
create mode 100644 include/llvm/Support/AlignOf.h
diff --git a/include/llvm/Support/AlignOf.h b/include/llvm/Support/AlignOf.h
new file mode 100644
index 00000000000..f27ecdd7130
--- /dev/null
+++ b/include/llvm/Support/AlignOf.h
@@ -0,0 +1,43 @@
+//===--- AlignOf.h - Portable calculation of type alignment -----*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Ted Kremenek and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the AlignOf function that computes alignments for
+// arbitrary types.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_ALIGNOF_H
+#define LLVM_SUPPORT_ALIGNOF_H
+
+#include <cassert>
+
+namespace llvm {
+
+template <typename T>
+struct AlignmentCalcImpl {
+ char x;
+ T t;
+private:
+ AlignmentCalcImpl() {} // Never instantiate.
+};
+
+/// AlignOf - A templated class that contains an enum value representing
+/// the alignment of the template argument. For example,
+/// AlignOf<int>::Alignment represents the alignment of type "int". The
+/// alignment calculated is the minimum alignment, and not necessarily
+/// the "desired" alignment returned by GCC's __alignof__ (for example). Note
+/// that because the alignment is an enum value, it can be used as a
+/// compile-time constant (e.g., for template instantiation).
+template <typename T>
+struct AlignOf {
+ enum { Alignment = sizeof(AlignmentCalcImpl<T>) - sizeof(T) };
+};
+
+} // end namespace llvm
+#endif