3 files changed, 372 insertions, 0 deletions
diff --git a/libjulia/backends/AbstractAssembly.h b/libjulia/backends/evm/AbstractAssembly.h
index e3afa2b6..e3afa2b6 100644
--- a/libjulia/backends/AbstractAssembly.h
+++ b/libjulia/backends/evm/AbstractAssembly.h
diff --git a/libjulia/backends/evm/EVMCodeTransform.cpp b/libjulia/backends/evm/EVMCodeTransform.cpp
new file mode 100644
index 00000000..18c3e63c
--- /dev/null
+++ b/libjulia/backends/evm/EVMCodeTransform.cpp
@@ -0,0 +1,253 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Common code generator for translating Julia / inline assembly to EVM and EVM1.5.
+ */
+
+#include <libjulia/backends/evm/EVMCodeTransform.h>
+
+#include <libsolidity/inlineasm/AsmAnalysisInfo.h>
+#include <libsolidity/inlineasm/AsmData.h>
+
+#include <libsolidity/interface/Utils.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::julia;
+using namespace dev::solidity;
+using namespace dev::solidity::assembly;
+
+CodeTransform::CodeTransform(
+	ErrorList& _errors,
+	AbstractAssembly& _assembly,
+	Block const& _block,
+	AsmAnalysisInfo& _analysisInfo,
+	ExternalIdentifierAccess const& _identifierAccess,
+	int _initialStackHeight
+):
+	m_errors(_errors),
+	m_assembly(_assembly),
+	m_info(_analysisInfo),
+	m_scope(*_analysisInfo.scopes.at(&_block)),
+	m_identifierAccess(_identifierAccess),
+	m_initialStackHeight(_initialStackHeight)
+{
+	int blockStartStackHeight = m_assembly.stackHeight();
+	std::for_each(_block.statements.begin(), _block.statements.end(), boost::apply_visitor(*this));
+
+	m_assembly.setSourceLocation(_block.location);
+
+	// pop variables
+	for (auto const& identifier: m_scope.identifiers)
+		if (identifier.second.type() == typeid(Scope::Variable))
+			m_assembly.appendInstruction(solidity::Instruction::POP);
+
+	int deposit = m_assembly.stackHeight() - blockStartStackHeight;
+	solAssert(deposit == 0, "Invalid stack height at end of block.");
+}
+
+void CodeTransform::operator()(const FunctionDefinition&)
+{
+	solAssert(false, "Function definition not removed during desugaring phase.");
+}
+
+void CodeTransform::generateAssignment(Identifier const& _variableName, SourceLocation const& _location)
+{
+	auto var = m_scope.lookup(_variableName.name);
+	if (var)
+	{
+		Scope::Variable const& _var = boost::get<Scope::Variable>(*var);
+		if (int heightDiff = variableHeightDiff(_var, _location, true))
+			m_assembly.appendInstruction(solidity::swapInstruction(heightDiff - 1));
+		m_assembly.appendInstruction(solidity::Instruction::POP);
+	}
+	else
+	{
+		solAssert(
+			m_identifierAccess.generateCode,
+			"Identifier not found and no external access available."
+		);
+		m_identifierAccess.generateCode(_variableName, IdentifierContext::LValue, m_assembly);
+	}
+}
+
+int CodeTransform::variableHeightDiff(solidity::assembly::Scope::Variable const& _var, SourceLocation const& _location, bool _forSwap)
+{
+	int heightDiff = m_assembly.stackHeight() - _var.stackHeight;
+	if (heightDiff <= (_forSwap ? 1 : 0) || heightDiff > (_forSwap ? 17 : 16))
+	{
+		//@TODO move this to analysis phase.
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::TypeError,
+			"Variable inaccessible, too deep inside stack (" + boost::lexical_cast<string>(heightDiff) + ")",
+			_location
+		));
+		return 0;
+	}
+	else
+		return heightDiff;
+}
+
+void CodeTransform::expectDeposit(int _deposit, int _oldHeight)
+{
+	solAssert(m_assembly.stackHeight() == _oldHeight + _deposit, "Invalid stack deposit.");
+}
+
+void CodeTransform::checkStackHeight(void const* _astElement)
+{
+	solAssert(m_info.stackHeightInfo.count(_astElement), "Stack height for AST element not found.");
+	solAssert(
+		m_info.stackHeightInfo.at(_astElement) == m_assembly.stackHeight() - m_initialStackHeight,
+		"Stack height mismatch between analysis and code generation phase."
+	);
+}
+
+void CodeTransform::assignLabelIdIfUnset(Scope::Label& _label)
+{
+	if (!_label.id)
+		_label.id.reset(m_assembly.newLabelId());
+}
+
+void CodeTransform::operator()(Block const& _block)
+{
+	CodeTransform(m_errors, m_assembly, _block, m_info, m_identifierAccess, m_initialStackHeight);
+	checkStackHeight(&_block);
+}
+
+void CodeTransform::operator()(Switch const&)
+{
+	solAssert(false, "Switch not removed during desugaring phase.");
+}
+
+void CodeTransform::operator()(VariableDeclaration const& _varDecl)
+{
+	int expectedItems = _varDecl.variables.size();
+	int height = m_assembly.stackHeight();
+	boost::apply_visitor(*this, *_varDecl.value);
+	expectDeposit(expectedItems, height);
+	for (auto const& variable: _varDecl.variables)
+	{
+		auto& var = boost::get<Scope::Variable>(m_scope.identifiers.at(variable.name));
+		var.stackHeight = height++;
+		var.active = true;
+	}
+}
+
+void CodeTransform::operator()(Assignment const& _assignment)
+{
+	int height = m_assembly.stackHeight();
+	boost::apply_visitor(*this, *_assignment.value);
+	expectDeposit(1, height);
+	m_assembly.setSourceLocation(_assignment.location);
+	generateAssignment(_assignment.variableName, _assignment.location);
+	checkStackHeight(&_assignment);
+}
+
+void CodeTransform::operator()(StackAssignment const& _assignment)
+{
+	m_assembly.setSourceLocation(_assignment.location);
+	generateAssignment(_assignment.variableName, _assignment.location);
+	checkStackHeight(&_assignment);
+}
+
+void CodeTransform::operator()(Label const& _label)
+{
+	m_assembly.setSourceLocation(_label.location);
+	solAssert(m_scope.identifiers.count(_label.name), "");
+	Scope::Label& label = boost::get<Scope::Label>(m_scope.identifiers.at(_label.name));
+	assignLabelIdIfUnset(label);
+	m_assembly.appendLabel(*label.id);
+	checkStackHeight(&_label);
+}
+
+void CodeTransform::operator()(FunctionCall const&)
+{
+	solAssert(false, "Function call not removed during desugaring phase.");
+}
+
+void CodeTransform::operator()(FunctionalInstruction const& _instr)
+{
+	for (auto it = _instr.arguments.rbegin(); it != _instr.arguments.rend(); ++it)
+	{
+		int height = m_assembly.stackHeight();
+		boost::apply_visitor(*this, *it);
+		expectDeposit(1, height);
+	}
+	(*this)(_instr.instruction);
+	checkStackHeight(&_instr);
+}
+
+void CodeTransform::operator()(assembly::Identifier const& _identifier)
+{
+	m_assembly.setSourceLocation(_identifier.location);
+	// First search internals, then externals.
+	if (m_scope.lookup(_identifier.name, Scope::NonconstVisitor(
+		[=](Scope::Variable& _var)
+		{
+			if (int heightDiff = variableHeightDiff(_var, _identifier.location, false))
+				m_assembly.appendInstruction(solidity::dupInstruction(heightDiff));
+			else
+				// Store something to balance the stack
+				m_assembly.appendConstant(u256(0));
+		},
+		[=](Scope::Label& _label)
+		{
+			assignLabelIdIfUnset(_label);
+			m_assembly.appendLabelReference(*_label.id);
+		},
+		[=](Scope::Function&)
+		{
+			solAssert(false, "Function not removed during desugaring.");
+		}
+	)))
+	{
+		return;
+	}
+	solAssert(
+		m_identifierAccess.generateCode,
+		"Identifier not found and no external access available."
+	);
+	m_identifierAccess.generateCode(_identifier, IdentifierContext::RValue, m_assembly);
+	checkStackHeight(&_identifier);
+}
+
+void CodeTransform::operator()(assembly::Literal const& _literal)
+{
+	m_assembly.setSourceLocation(_literal.location);
+	if (_literal.kind == assembly::LiteralKind::Number)
+		m_assembly.appendConstant(u256(_literal.value));
+	else if (_literal.kind == assembly::LiteralKind::Boolean)
+	{
+		if (_literal.value == "true")
+			m_assembly.appendConstant(u256(1));
+		else
+			m_assembly.appendConstant(u256(0));
+	}
+	else
+	{
+		solAssert(_literal.value.size() <= 32, "");
+		m_assembly.appendConstant(u256(h256(_literal.value, h256::FromBinary, h256::AlignLeft)));
+	}
+	checkStackHeight(&_literal);
+}
+
+void CodeTransform::operator()(assembly::Instruction const& _instruction)
+{
+	m_assembly.setSourceLocation(_instruction.location);
+	m_assembly.appendInstruction(_instruction.instruction);
+	checkStackHeight(&_instruction);
+}
diff --git a/libjulia/backends/evm/EVMCodeTransform.h b/libjulia/backends/evm/EVMCodeTransform.h
new file mode 100644
index 00000000..5408a3aa
--- /dev/null
+++ b/libjulia/backends/evm/EVMCodeTransform.h
@@ -0,0 +1,119 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Common code generator for translating Julia / inline assembly to EVM and EVM1.5.
+ */
+
+#include <libjulia/backends/evm/AbstractAssembly.h>
+
+#include <libsolidity/interface/Exceptions.h>
+
+#include <libsolidity/inlineasm/AsmStack.h>
+#include <libsolidity/inlineasm/AsmScope.h>
+
+#include <boost/variant.hpp>
+
+namespace dev
+{
+namespace solidity
+{
+namespace assembly
+{
+struct Literal;
+struct Block;
+struct Switch;
+struct Label;
+struct FunctionalInstruction;
+struct Assignment;
+struct VariableDeclaration;
+struct Instruction;
+struct Identifier;
+struct StackAssignment;
+struct FunctionDefinition;
+struct FunctionCall;
+
+struct AsmAnalysisInfo;
+}
+}
+namespace julia
+{
+
+class CodeTransform: public boost::static_visitor<>
+{
+public:
+	/// Create the code transformer which appends assembly to _assembly as a side-effect
+	/// of its creation.
+	/// @param _identifierAccess used to resolve identifiers external to the inline assembly
+	CodeTransform(
+		solidity::ErrorList& _errors,
+		julia::AbstractAssembly& _assembly,
+		solidity::assembly::Block const& _block,
+		solidity::assembly::AsmAnalysisInfo& _analysisInfo,
+		ExternalIdentifierAccess const& _identifierAccess = ExternalIdentifierAccess()
+	): CodeTransform(_errors, _assembly, _block, _analysisInfo, _identifierAccess, _assembly.stackHeight())
+	{
+	}
+
+private:
+	CodeTransform(
+		solidity::ErrorList& _errors,
+		julia::AbstractAssembly& _assembly,
+		solidity::assembly::Block const& _block,
+		solidity::assembly::AsmAnalysisInfo& _analysisInfo,
+		ExternalIdentifierAccess const& _identifierAccess,
+		int _initialStackHeight
+	);
+
+public:
+	void operator()(solidity::assembly::Instruction const& _instruction);
+	void operator()(solidity::assembly::Literal const& _literal);
+	void operator()(solidity::assembly::Identifier const& _identifier);
+	void operator()(solidity::assembly::FunctionalInstruction const& _instr);
+	void operator()(solidity::assembly::FunctionCall const&);
+	void operator()(solidity::assembly::Label const& _label);
+	void operator()(solidity::assembly::StackAssignment const& _assignment);
+	void operator()(solidity::assembly::Assignment const& _assignment);
+	void operator()(solidity::assembly::VariableDeclaration const& _varDecl);
+	void operator()(solidity::assembly::Block const& _block);
+	void operator()(solidity::assembly::Switch const& _switch);
+	void operator()(solidity::assembly::FunctionDefinition const&);
+
+private:
+	void generateAssignment(solidity::assembly::Identifier const& _variableName, SourceLocation const& _location);
+
+	/// Determines the stack height difference to the given variables. Automatically generates
+	/// errors if it is not yet in scope or the height difference is too large. Returns 0 on
+	/// errors and the (positive) stack height difference otherwise.
+	int variableHeightDiff(solidity::assembly::Scope::Variable const& _var, SourceLocation const& _location, bool _forSwap);
+
+	void expectDeposit(int _deposit, int _oldHeight);
+
+	void checkStackHeight(void const* _astElement);
+
+	/// Assigns the label's id to a value taken from eth::Assembly if it has not yet been set.
+	void assignLabelIdIfUnset(solidity::assembly::Scope::Label& _label);
+
+	solidity::ErrorList& m_errors;
+	julia::AbstractAssembly& m_assembly;
+	solidity::assembly::AsmAnalysisInfo& m_info;
+	solidity::assembly::Scope& m_scope;
+	ExternalIdentifierAccess m_identifierAccess;
+	int const m_initialStackHeight;
+};
+
+}
+}