Preliminary why3 code output.

1 files changed, 115 insertions, 0 deletions

diff --git a/libsolidity/formal/Why3Translator.h b/libsolidity/formal/Why3Translator.h
new file mode 100644
index 00000000..21ead977
--- /dev/null
+++ b/libsolidity/formal/Why3Translator.h
@@ -0,0 +1,115 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum 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.
+
+	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @author Christian <c@ethdev.com>
+ * @date 2015
+ * Component that translates Solidity code into the why3 programming language.
+ */
+
+#pragma once
+
+#include <libsolidity/ast/ASTVisitor.h>
+#include <libsolidity/interface/Exceptions.h>
+#include <string>
+
+namespace dev
+{
+namespace solidity
+{
+
+class SourceUnit;
+
+/**
+ * Simple translator from Solidity to Why3.
+ *
+ * @todo detect side effects in sub-expressions and limit them to one per statement.
+ * @todo `x = y = z`
+ * @todo implicit and explicit type conversion
+ */
+class Why3Translator: private ASTConstVisitor
+{
+public:
+	Why3Translator(ErrorList& _errors): m_errors(_errors) {}
+
+	/// Appends formalisation of the given source unit to the output.
+	/// @returns false on error.
+	bool process(SourceUnit const& _source);
+
+	std::string translation() const { return m_result; }
+
+private:
+	/// Returns an error.
+	void error(ASTNode const& _node, std::string const& _description);
+	/// Reports a fatal error and throws.
+	void fatalError(ASTNode const& _node, std::string const& _description);
+
+	/// Appends imports and constants use throughout the formal code.
+	void appendPreface();
+
+	/// @returns a string representation of the corresponding formal type or the empty string
+	/// if the type is not supported.
+	std::string toFormalType(Type const& _type) const;
+
+	void indent() { m_indentation++; }
+	void unindent();
+	void addLine(std::string const& _line);
+	void add(std::string const& _str);
+	void newLine();
+
+	virtual bool visit(SourceUnit const&) override { return true; }
+	virtual bool visit(ContractDefinition const& _contract) override;
+	virtual bool visit(FunctionDefinition const& _function) override;
+	virtual bool visit(Block const&) override;
+	virtual void endVisit(Block const&) override { unindent(); addLine("end;"); }
+	virtual bool visit(IfStatement const& _node) override;
+	virtual bool visit(WhileStatement const& _node) override;
+	virtual bool visit(Return const& _node) override;
+	virtual bool visit(VariableDeclarationStatement const& _node) override;
+	virtual bool visit(ExpressionStatement const&) override;
+	virtual void endVisit(ExpressionStatement const&) override { add(";"); newLine(); }
+	virtual bool visit(Assignment const& _node) override;
+	virtual bool visit(TupleExpression const& _node) override;
+	virtual void endVisit(TupleExpression const&) override { add(")"); }
+	virtual bool visit(UnaryOperation const& _node) override;
+	virtual bool visit(BinaryOperation const& _node) override;
+	virtual bool visit(FunctionCall const& _node) override;
+	virtual bool visit(MemberAccess const& _node) override;
+	virtual bool visit(IndexAccess const& _node) override;
+	virtual bool visit(Identifier const& _node) override;
+	virtual bool visit(Literal const& _node) override;
+
+	virtual bool visitNode(ASTNode const& _node) override
+	{
+		error(_node, "Code not supported for formal verification.");
+		return false;
+	}
+
+	void addSourceFromDocStrings(DocumentedAnnotation const& _annotation);
+
+	size_t m_indentation = 0;
+	std::string m_currentLine;
+	/// True if we have already seen a contract. For now, only a single contract
+	/// is supported.
+	bool m_seenContract = false;
+	bool m_errorOccured = false;
+	std::string m_result;
+	ErrorList& m_errors;
+};
+
+
+}
+}