From 4608d2402725cb2d967fd5b3b4c56cf50f7ec7eb Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Wed, 14 Aug 2019 11:27:49 +1000
Subject: [PATCH] debug/memory: add asan and valgrind annotation functions

---
 CMakeLists.txt   |   2 +
 debug/memory.cpp | 129 +++++++++++++++++++++++++++++++++++++++++++++++
 debug/memory.hpp |  40 +++++++++++++++
 3 files changed, 171 insertions(+)
 create mode 100644 debug/memory.cpp
 create mode 100644 debug/memory.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0c01969d..dbd3fd5c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -305,6 +305,8 @@ list (
     debug/compiler.hpp
     debug/debugger.cpp
     debug/debugger.hpp
+    debug/memory.cpp
+    debug/memory.hpp
     debug/panic.cpp
     debug/panic.hpp
     debug/system.cpp
diff --git a/debug/memory.cpp b/debug/memory.cpp
new file mode 100644
index 00000000..e9e615a6
--- /dev/null
+++ b/debug/memory.cpp
@@ -0,0 +1,129 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright 2019 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "memory.hpp"
+
+#include "std.hpp"
+#include "maths.hpp"
+#include "debug/panic.hpp"
+
+
+///////////////////////////////////////////////////////////////////////////////
+#ifndef __has_feature
+#define __has_feature(X) 0
+#endif
+
+
+//-----------------------------------------------------------------------------
+#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
+#include <sanitizer/asan_interface.h>
+static std::align_val_t asan_alignment (void)
+{
+    return std::align_val_t {8u};
+}
+
+
+static void asan_undefined (void const volatile *addr, std::size_t size)
+{
+    return ASAN_POISON_MEMORY_REGION ((addr), (size));
+}
+
+
+static void asan_defined (void const volatile *addr, std::size_t size)
+{
+    return ASAN_UNPOISON_MEMORY_REGION ((addr), (size));
+}
+#else
+static std::align_val_t asan_alignment (void)
+{
+    return std::align_val_t {1u};
+}
+
+
+static void asan_undefined (void const volatile *addr, std::size_t size)
+{
+    (void)addr;
+    (void)size;
+}
+
+
+static void asan_defined (void const volatile *addr, std::size_t size)
+{
+    (void)addr;
+    (void)size;
+}
+#endif
+
+
+///////////////////////////////////////////////////////////////////////////////
+static std::align_val_t vg_alignment (void)
+{
+    return std::align_val_t {1u};
+}
+
+
+//-----------------------------------------------------------------------------
+#if __has_include("valgrind/memcheck.h")
+#include <valgrind/memcheck.h>
+static void vg_undefined (void const volatile *addr, std::size_t len)
+{
+    VALGRIND_MAKE_MEM_UNDEFINED (addr, len);
+}
+
+
+//-----------------------------------------------------------------------------
+static void vg_defined (void const volatile *addr, std::size_t len)
+{
+    VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (addr, len);
+}
+#else
+//-----------------------------------------------------------------------------
+static void vg_undefined (void const volatile *addr, std::size_t len)
+{
+    (void)addr;
+    (void)len;
+}
+
+
+//-----------------------------------------------------------------------------
+static void vg_defined (void const volatile *addr, std::size_t len)
+{
+    (void)addr;
+    (void)len;
+}
+#endif
+
+
+///////////////////////////////////////////////////////////////////////////////
+std::align_val_t
+cruft::debug::memory::instrumentation_alignment (void)
+{
+    return cruft::max (
+        asan_alignment (),
+        vg_alignment (),
+        std::align_val_t {1u}
+    );
+}
+
+
+//-----------------------------------------------------------------------------
+void
+cruft::debug::memory::mark_undefined (void const volatile *ptr, std::size_t len)
+{
+    asan_undefined (ptr, len);
+    vg_undefined (ptr, len);
+}
+
+
+//-----------------------------------------------------------------------------
+void
+cruft::debug::memory::mark_defined (void const volatile *ptr, std::size_t len)
+{
+    asan_defined (ptr, len);
+    vg_defined (ptr, len);
+}
diff --git a/debug/memory.hpp b/debug/memory.hpp
new file mode 100644
index 00000000..887ec58d
--- /dev/null
+++ b/debug/memory.hpp
@@ -0,0 +1,40 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright 2019 Danny Robson <danny@nerdcruft.net>
+ */
+
+#pragma once
+
+#include "../view.hpp"
+
+namespace cruft::debug::memory {
+    /// Returns the required alignment for instrumented memory accesses.
+    std::align_val_t instrumentation_alignment (void);
+
+
+    /// Label the contents of this memory region as undefined.
+    void mark_undefined (void const volatile*, std::size_t);
+
+
+    //-------------------------------------------------------------------------
+    template <typename ValueT>
+    void mark_undefined (cruft::view<ValueT const *> mem)
+    {
+        return mark_undefined (mem.data (), mem.size () * sizeof (ValueT));
+    }
+
+
+    /// Label the contents of this memory region as defined
+    void mark_defined (void const volatile*, std::size_t);
+
+
+    //-------------------------------------------------------------------------
+    template <typename ValueT>
+    void mark_defined (cruft::view<ValueT const *> mem)
+    {
+        return mark_defined (mem.data (), mem.size () * sizeof (ValueT));
+    }
+}