From 2505b8ed9007a9c4c1423d3ad460d7ed8f81b8ef Mon Sep 17 00:00:00 2001
From: chriseth <c@ethdev.com>
Date: Mon, 16 Mar 2015 16:15:13 +0100
Subject: [PATCH] Provide access to storage offsets via contract type.

---
 libsolidity/Compiler.cpp | 17 +++--------------
 libsolidity/Types.cpp    | 26 +++++++++++++++++++++++---
 libsolidity/Types.h      |  4 ++++
 3 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/libsolidity/Compiler.cpp b/libsolidity/Compiler.cpp
index db61cc4a1..8e2634499 100644
--- a/libsolidity/Compiler.cpp
+++ b/libsolidity/Compiler.cpp
@@ -20,12 +20,12 @@
  * Solidity compiler.
  */
 
+#include <libsolidity/Compiler.h>
 #include <algorithm>
 #include <boost/range/adaptor/reversed.hpp>
 #include <libevmcore/Instruction.h>
 #include <libevmcore/Assembly.h>
 #include <libsolidity/AST.h>
-#include <libsolidity/Compiler.h>
 #include <libsolidity/ExpressionCompiler.h>
 #include <libsolidity/CompilerUtils.h>
 
@@ -274,19 +274,8 @@ void Compiler::appendReturnValuePacker(TypePointers const& _typeParameters)
 
 void Compiler::registerStateVariables(ContractDefinition const& _contract)
 {
-	vector<VariableDeclaration const*> variables;
-	for (ContractDefinition const* contract: boost::adaptors::reverse(_contract.getLinearizedBaseContracts()))
-		for (ASTPointer<VariableDeclaration> const& variable: contract->getStateVariables())
-			if (!variable->isConstant())
-				variables.push_back(variable.get());
-	TypePointers types;
-	for (auto variable: variables)
-		types.push_back(variable->getType());
-	StorageOffsets offsets;
-	offsets.computeOffsets(types);
-	for (size_t index = 0; index < variables.size(); ++index)
-		if (auto const* offset = offsets.getOffset(index))
-			m_context.addStateVariable(*variables[index], offset->first, offset->second);
+	for (auto const& var: ContractType(_contract).getStateVariables())
+		m_context.addStateVariable(*get<0>(var), get<1>(var), get<2>(var));
 }
 
 void Compiler::initializeStateVariables(ContractDefinition const& _contract)
diff --git a/libsolidity/Types.cpp b/libsolidity/Types.cpp
index 04f86b922..ed3cb8fd1 100644
--- a/libsolidity/Types.cpp
+++ b/libsolidity/Types.cpp
@@ -20,14 +20,14 @@
  * Solidity data types
  */
 
+#include <libsolidity/Types.h>
+#include <limits>
+#include <boost/range/adaptor/reversed.hpp>
 #include <libdevcore/CommonIO.h>
 #include <libdevcore/CommonData.h>
 #include <libsolidity/Utils.h>
-#include <libsolidity/Types.h>
 #include <libsolidity/AST.h>
 
-#include <limits>
-
 using namespace std;
 
 namespace dev
@@ -812,6 +812,26 @@ u256 ContractType::getFunctionIdentifier(string const& _functionName) const
 	return Invalid256;
 }
 
+vector<tuple<VariableDeclaration const*, u256, unsigned>> ContractType::getStateVariables() const
+{
+	vector<VariableDeclaration const*> variables;
+	for (ContractDefinition const* contract: boost::adaptors::reverse(m_contract.getLinearizedBaseContracts()))
+		for (ASTPointer<VariableDeclaration> const& variable: contract->getStateVariables())
+			if (!variable->isConstant())
+				variables.push_back(variable.get());
+	TypePointers types;
+	for (auto variable: variables)
+		types.push_back(variable->getType());
+	StorageOffsets offsets;
+	offsets.computeOffsets(types);
+
+	vector<tuple<VariableDeclaration const*, u256, unsigned>> variablesAndOffsets;
+	for (size_t index = 0; index < variables.size(); ++index)
+		if (auto const* offset = offsets.getOffset(index))
+			variablesAndOffsets.push_back(make_tuple(variables[index], offset->first, offset->second));
+	return variablesAndOffsets;
+}
+
 TypePointer StructType::unaryOperatorResult(Token::Value _operator) const
 {
 	return _operator == Token::Delete ? make_shared<VoidType>() : TypePointer();
diff --git a/libsolidity/Types.h b/libsolidity/Types.h
index e7601fde8..c7dbcdeb9 100644
--- a/libsolidity/Types.h
+++ b/libsolidity/Types.h
@@ -403,6 +403,10 @@ public:
 	/// not exist.
 	u256 getFunctionIdentifier(std::string const& _functionName) const;
 
+	/// @returns a list of all state variables (including inherited) of the contract and their
+	/// offsets in storage.
+	std::vector<std::tuple<VariableDeclaration const*, u256, unsigned>> getStateVariables() const;
+
 private:
 	ContractDefinition const& m_contract;
 	/// If true, it is the "super" type of the current contract, i.e. it contains only inherited