From b11b9939f4f06fa793648d75c3c2d3e4d82cdbf9 Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Sun, 28 Jun 2015 16:07:33 -0700
Subject: [PATCH] Add contract interface

---
 Builds/VisualStudio2013/RippleD.vcxproj       |  4 ++
 .../VisualStudio2013/RippleD.vcxproj.filters  |  3 +
 src/ripple/basics/contract.h                  | 64 +++++++++++++++++++
 src/ripple/basics/impl/contract.cpp           | 52 +++++++++++++++
 src/ripple/unity/basics.cpp                   |  1 +
 5 files changed, 124 insertions(+)
 create mode 100644 src/ripple/basics/contract.h
 create mode 100644 src/ripple/basics/impl/contract.cpp

diff --git a/Builds/VisualStudio2013/RippleD.vcxproj b/Builds/VisualStudio2013/RippleD.vcxproj
index 669533588e..303da0ca90 100644
--- a/Builds/VisualStudio2013/RippleD.vcxproj
+++ b/Builds/VisualStudio2013/RippleD.vcxproj
@@ -1885,6 +1885,10 @@
     </ClCompile>
     <ClInclude Include="..\..\src\ripple\basics\impl\CheckLibraryVersionsImpl.h">
     </ClInclude>
+    <ClCompile Include="..\..\src\ripple\basics\impl\contract.cpp">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='debug|x64'">True</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='release|x64'">True</ExcludedFromBuild>
+    </ClCompile>
     <ClCompile Include="..\..\src\ripple\basics\impl\CountedObject.cpp">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='debug|x64'">True</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='release|x64'">True</ExcludedFromBuild>
diff --git a/Builds/VisualStudio2013/RippleD.vcxproj.filters b/Builds/VisualStudio2013/RippleD.vcxproj.filters
index bb2a49d0f4..2d32fa1b4c 100644
--- a/Builds/VisualStudio2013/RippleD.vcxproj.filters
+++ b/Builds/VisualStudio2013/RippleD.vcxproj.filters
@@ -2616,6 +2616,9 @@
     <ClInclude Include="..\..\src\ripple\basics\impl\CheckLibraryVersionsImpl.h">
       <Filter>ripple\basics\impl</Filter>
     </ClInclude>
+    <ClCompile Include="..\..\src\ripple\basics\impl\contract.cpp">
+      <Filter>ripple\basics\impl</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\ripple\basics\impl\CountedObject.cpp">
       <Filter>ripple\basics\impl</Filter>
     </ClCompile>
diff --git a/src/ripple/basics/contract.h b/src/ripple/basics/contract.h
new file mode 100644
index 0000000000..a4a7a849ea
--- /dev/null
+++ b/src/ripple/basics/contract.h
@@ -0,0 +1,64 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2014 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_CONTRACT_H_INCLUDED
+#define RIPPLE_BASICS_CONTRACT_H_INCLUDED
+
+#include <exception>
+#include <string>
+#include <utility>
+
+namespace ripple {
+
+/*  Programming By Contract
+
+    This routines are used when checking
+    preconditions, postconditions, and invariants.
+*/
+
+namespace detail {
+
+void
+accessViolation();
+
+void
+throwException(
+    std::exception_ptr ep);
+
+} // detail
+
+template <class Exception,
+    class... Args>
+void
+Throw (Args&&... args)
+{
+    throwException(
+        std::make_exception_ptr(
+            Exception(std::forward<
+                Args>(args)...)));
+}
+
+/** Called when faulty logic causes a broken invariant. */
+void
+LogicError (
+    std::string const& how);
+
+} // ripple
+
+#endif
diff --git a/src/ripple/basics/impl/contract.cpp b/src/ripple/basics/impl/contract.cpp
new file mode 100644
index 0000000000..e10673d33d
--- /dev/null
+++ b/src/ripple/basics/impl/contract.cpp
@@ -0,0 +1,52 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2012, 2013 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <BeastConfig.h>
+#include <ripple/basics/contract.h>
+
+namespace ripple {
+
+namespace detail {
+
+void
+accessViolation()
+{
+    // dereference memory
+    // location zero
+    int* j = 0;
+    *j++;
+}
+
+// This hook lets you do pre or post
+// processing on exceptions to suit needs.
+void
+throwException (std::exception_ptr ep)
+{
+    std::rethrow_exception(ep);
+}
+
+} // detail
+
+void
+LogicError (std::string const&)
+{
+    detail::accessViolation();
+}
+
+} // ripple
diff --git a/src/ripple/unity/basics.cpp b/src/ripple/unity/basics.cpp
index 0e3ad14609..fa4da07fe7 100644
--- a/src/ripple/unity/basics.cpp
+++ b/src/ripple/unity/basics.cpp
@@ -21,6 +21,7 @@
 
 #include <ripple/basics/impl/BasicConfig.cpp>
 #include <ripple/basics/impl/CheckLibraryVersions.cpp>
+#include <ripple/basics/impl/contract.cpp>
 #include <ripple/basics/impl/CountedObject.cpp>
 #include <ripple/basics/impl/Log.cpp>
 #include <ripple/basics/impl/make_SSLContext.cpp>