Refactoring: Check types outside of AST and recover from some errors.

1 files changed, 114 insertions, 0 deletions

diff --git a/libsolidity/TypeChecker.h b/libsolidity/TypeChecker.h
new file mode 100644
index 00000000..90e2a01b
--- /dev/null
+++ b/libsolidity/TypeChecker.h
@@ -0,0 +1,114 @@
+/*
+	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
+ * Type analyzer and checker.
+ */
+
+#pragma once
+
+#include <libsolidity/TypeChecker.h>
+#include <libsolidity/Types.h>
+#include <libsolidity/ASTAnnotations.h>
+#include <libsolidity/ASTForward.h>
+#include <libsolidity/ASTVisitor.h>
+
+namespace dev
+{
+namespace solidity
+{
+
+
+/**
+ * The module that performs type analysis on the AST, checks the applicability of operations on
+ * those types and stores errors for invalid operations.
+ * Provides a way to retrieve the type of an AST node.
+ */
+class TypeChecker: private ASTConstVisitor
+{
+public:
+	/// Performs type checking on the given contract and all of its sub-nodes.
+	/// @returns true iff all checks passed.
+	bool checkTypeRequirements(ContractDefinition const& _contract);
+
+	/// @returns the list of errors found during type checking.
+	std::vector<std::shared_ptr<Exception const>> const& errors() const { return m_errors; }
+
+	/// @returns the type of an expression and asserts that it is present.
+	TypePointer const& type(Expression const& _expression) const;
+	/// @returns the type of the given variable and throws if the type is not present
+	/// (this can happen for variables with non-explicit types before their types are resolved)
+	TypePointer const& type(VariableDeclaration const& _variable) const;
+
+	/// Adds a new error to the list of errors.
+	void typeError(ASTNode const& _node, std::string const& _description);
+	/// Adds a new error to the list of errors and throws to abort type checking.
+	void fatalTypeError(ASTNode const& _node, std::string const& _description);
+
+private:
+	virtual bool visit(ContractDefinition const& _contract) override;
+	/// Checks that two functions defined in this contract with the same name have different
+	/// arguments and that there is at most one constructor.
+	void checkContractDuplicateFunctions(ContractDefinition const& _contract);
+	void checkContractIllegalOverrides(ContractDefinition const& _contract);
+	void checkContractAbstractFunctions(ContractDefinition const& _contract);
+	void checkContractAbstractConstructors(ContractDefinition const& _contract);
+	/// Checks that different functions with external visibility end up having different
+	/// external argument types (i.e. different signature).
+	void checkContractExternalTypeClashes(ContractDefinition const& _contract);
+	/// Checks that all requirements for a library are fulfilled if this is a library.
+	void checkLibraryRequirements(ContractDefinition const& _contract);
+
+	virtual void endVisit(InheritanceSpecifier const& _inheritance) override;
+	virtual bool visit(StructDefinition const& _struct) override;
+	virtual bool visit(FunctionDefinition const& _function) override;
+	virtual bool visit(VariableDeclaration const& _variable) override;
+	/// We need to do this manually because we want to pass the bases of the current contract in
+	/// case this is a base constructor call.
+	void visitManually(ModifierInvocation const& _modifier, std::vector<ContractDefinition const*> const& _bases);
+	virtual bool visit(EventDefinition const& _eventDef) override;
+	virtual bool visit(IfStatement const& _ifStatement) override;
+	virtual bool visit(WhileStatement const& _whileStatement) override;
+	virtual bool visit(ForStatement const& _forStatement) override;
+	virtual void endVisit(Return const& _return) override;
+	virtual void endVisit(ExpressionStatement const& _statement) override;
+	virtual bool visit(Assignment const& _assignment) override;
+	virtual void endVisit(BinaryOperation const& _operation) override;
+	virtual bool visit(UnaryOperation const& _operation) override;
+	virtual bool visit(FunctionCall const& _functionCall) override;
+	virtual void endVisit(NewExpression const& _newExpression) override;
+	virtual bool visit(MemberAccess const& _memberAccess) override;
+	virtual bool visit(IndexAccess const& _indexAccess) override;
+	virtual bool visit(Identifier const& _identifier) override;
+	virtual void endVisit(ElementaryTypeNameExpression const& _expr) override;
+	virtual void endVisit(Literal const& _literal) override;
+
+	/// @returns the referenced declaration and throws on error.
+	Declaration const& dereference(Identifier const& _identifier);
+
+	/// Runs type checks on @a _expression to infer its type and then checks that it is implicitly
+	/// convertible to @a _expectedType.
+	void expectType(Expression const& _expression, Type const& _expectedType);
+	/// Runs type checks on @a _expression to infer its type and then checks that it is an LValue.
+	void requireLValue(Expression const& _expression);
+
+	std::vector<std::shared_ptr<Exception const>> m_errors;
+};
+
+}
+}