Separate expression and statement.

9 files changed, 94 insertions, 32 deletions

diff --git a/libjulia/ASTDataForward.h b/libjulia/ASTDataForward.h
index 3806e321..143b9c46 100644
--- a/libjulia/ASTDataForward.h
+++ b/libjulia/ASTDataForward.h
@@ -42,11 +42,13 @@ using If = solidity::assembly::If;
 using Case = solidity::assembly::Case;
 using Switch = solidity::assembly::Switch;
 using ForLoop = solidity::assembly::ForLoop;
+using ExpressionStatement = solidity::assembly::ExpressionStatement;
 using Block = solidity::assembly::Block;
 
 using TypedName = solidity::assembly::TypedName;
 
-using Statement = boost::variant<Instruction, Literal, Label, StackAssignment, Identifier, Assignment, FunctionCall, FunctionalInstruction, VariableDeclaration, FunctionDefinition, If, Switch, ForLoop, Block>;
+using Expression = boost::variant<FunctionalInstruction, FunctionCall, Identifier, Literal>;
+using Statement = boost::variant<ExpressionStatement, Instruction, Label, StackAssignment, Assignment, VariableDeclaration, FunctionDefinition, If, Switch, ForLoop, Block>;
 
 }
 }
diff --git a/libjulia/backends/evm/EVMCodeTransform.cpp b/libjulia/backends/evm/EVMCodeTransform.cpp
index f92939be..0c7365fb 100644
--- a/libjulia/backends/evm/EVMCodeTransform.cpp
+++ b/libjulia/backends/evm/EVMCodeTransform.cpp
@@ -77,6 +77,13 @@ void CodeTransform::operator()(StackAssignment const& _assignment)
 	checkStackHeight(&_assignment);
 }
 
+void CodeTransform::operator()(ExpressionStatement const& _statement)
+{
+	m_assembly.setSourceLocation(_statement.location);
+	boost::apply_visitor(*this, _statement.expression);
+	checkStackHeight(&_statement);
+}
+
 void CodeTransform::operator()(Label const& _label)
 {
 	m_assembly.setSourceLocation(_label.location);
@@ -460,7 +467,7 @@ AbstractAssembly::LabelID CodeTransform::functionEntryID(string const& _name, Sc
 	return m_context->functionEntryIDs[&_function];
 }
 
-void CodeTransform::visitExpression(Statement const& _expression)
+void CodeTransform::visitExpression(Expression const& _expression)
 {
 	int height = m_assembly.stackHeight();
 	boost::apply_visitor(*this, _expression);
diff --git a/libjulia/backends/evm/EVMCodeTransform.h b/libjulia/backends/evm/EVMCodeTransform.h
index 577cc8ba..0f2aaf95 100644
--- a/libjulia/backends/evm/EVMCodeTransform.h
+++ b/libjulia/backends/evm/EVMCodeTransform.h
@@ -101,6 +101,7 @@ public:
 	void operator()(Identifier const& _identifier);
 	void operator()(FunctionalInstruction const& _instr);
 	void operator()(FunctionCall const&);
+	void operator()(ExpressionStatement const& _statement);
 	void operator()(Label const& _label);
 	void operator()(StackAssignment const& _assignment);
 	void operator()(Assignment const& _assignment);
@@ -118,7 +119,7 @@ private:
 	AbstractAssembly::LabelID labelID(solidity::assembly::Scope::Label const& _label);
 	AbstractAssembly::LabelID functionEntryID(std::string const& _name, solidity::assembly::Scope::Function const& _function);
 	/// Generates code for an expression that is supposed to return a single value.
-	void visitExpression(Statement const& _expression);
+	void visitExpression(Expression const& _expression);
 
 	void visitStatements(std::vector<Statement> const& _statements);
 
diff --git a/libjulia/optimiser/ASTCopier.cpp b/libjulia/optimiser/ASTCopier.cpp
index a461f434..5c47be64 100644
--- a/libjulia/optimiser/ASTCopier.cpp
+++ b/libjulia/optimiser/ASTCopier.cpp
@@ -37,6 +37,11 @@ Statement ASTCopier::operator()(Instruction const&)
 	return {};
 }
 
+Statement ASTCopier::operator()(ExpressionStatement const& _statement)
+{
+	return ExpressionStatement{ _statement.location, translate(_statement.expression) };
+}
+
 Statement ASTCopier::operator()(VariableDeclaration const& _varDecl)
 {
 	return VariableDeclaration{
@@ -67,7 +72,7 @@ Statement ASTCopier::operator()(Label const&)
 	return {};
 }
 
-Statement ASTCopier::operator()(FunctionCall const& _call)
+Expression ASTCopier::operator()(FunctionCall const& _call)
 {
 	return FunctionCall{
 		_call.location,
@@ -76,7 +81,7 @@ Statement ASTCopier::operator()(FunctionCall const& _call)
 	};
 }
 
-Statement ASTCopier::operator()(FunctionalInstruction const& _instruction)
+Expression ASTCopier::operator()(FunctionalInstruction const& _instruction)
 {
 	return FunctionalInstruction{
 		_instruction.location,
@@ -85,12 +90,12 @@ Statement ASTCopier::operator()(FunctionalInstruction const& _instruction)
 	};
 }
 
-Statement ASTCopier::operator()(Identifier const& _identifier)
+Expression ASTCopier::operator()(Identifier const& _identifier)
 {
 	return Identifier{_identifier.location, translateIdentifier(_identifier.name)};
 }
 
-Statement ASTCopier::operator()(Literal const& _literal)
+Expression ASTCopier::operator()(Literal const& _literal)
 {
 	return translate(_literal);
 }
@@ -140,9 +145,14 @@ Statement ASTCopier::operator ()(Block const& _block)
 	return translate(_block);
 }
 
+Expression ASTCopier::translate(Expression const& _expression)
+{
+	return _expression.apply_visitor(static_cast<ExpressionCopier&>(*this));
+}
+
 Statement ASTCopier::translate(Statement const& _statement)
 {
-	return boost::apply_visitor(*this, _statement);
+	return _statement.apply_visitor(static_cast<StatementCopier&>(*this));
 }
 
 Block ASTCopier::translate(Block const& _block)
diff --git a/libjulia/optimiser/ASTCopier.h b/libjulia/optimiser/ASTCopier.h
index 5dde2ce9..36a1ced5 100644
--- a/libjulia/optimiser/ASTCopier.h
+++ b/libjulia/optimiser/ASTCopier.h
@@ -34,28 +34,55 @@ namespace dev
 namespace julia
 {
 
+class ExpressionCopier: public boost::static_visitor<Expression>
+{
+public:
+	virtual Expression operator()(Literal const& _literal) = 0;
+	virtual Expression operator()(Identifier const& _identifier) = 0;
+	virtual Expression operator()(FunctionalInstruction const& _instr) = 0;
+	virtual Expression operator()(FunctionCall const&) = 0;
+};
+
+class StatementCopier: public boost::static_visitor<Statement>
+{
+public:
+	virtual Statement operator()(ExpressionStatement const& _statement) = 0;
+	virtual Statement operator()(Instruction const& _instruction) = 0;
+	virtual Statement operator()(Label const& _label) = 0;
+	virtual Statement operator()(StackAssignment const& _assignment) = 0;
+	virtual Statement operator()(Assignment const& _assignment) = 0;
+	virtual Statement operator()(VariableDeclaration const& _varDecl) = 0;
+	virtual Statement operator()(If const& _if) = 0;
+	virtual Statement operator()(Switch const& _switch) = 0;
+	virtual Statement operator()(FunctionDefinition const&) = 0;
+	virtual Statement operator()(ForLoop const&) = 0;
+	virtual Statement operator()(Block const& _block) = 0;
+};
+
 /**
  * Creates a copy of a iulia AST potentially replacing identifier names.
  * Base class to be extended.
  */
-class ASTCopier: public boost::static_visitor<Statement>
+class ASTCopier: public ExpressionCopier, public StatementCopier
 {
 public:
-	Statement operator()(Literal const& _literal);
-	Statement operator()(Instruction const& _instruction);
-	Statement operator()(Identifier const& _identifier);
-	Statement operator()(FunctionalInstruction const& _instr);
-	Statement operator()(FunctionCall const&);
-	Statement operator()(Label const& _label);
-	Statement operator()(StackAssignment const& _assignment);
-	Statement operator()(Assignment const& _assignment);
-	Statement operator()(VariableDeclaration const& _varDecl);
-	Statement operator()(If const& _if);
-	Statement operator()(Switch const& _switch);
-	Statement operator()(FunctionDefinition const&);
-	Statement operator()(ForLoop const&);
-	Statement operator()(Block const& _block);
-
+	virtual Expression operator()(Literal const& _literal) override;
+	virtual Statement operator()(Instruction const& _instruction) override;
+	virtual Expression operator()(Identifier const& _identifier) override;
+	virtual Expression operator()(FunctionalInstruction const& _instr) override;
+	virtual Expression operator()(FunctionCall const&) override;
+	virtual Statement operator()(ExpressionStatement const& _statement) override;
+	virtual Statement operator()(Label const& _label) override;
+	virtual Statement operator()(StackAssignment const& _assignment) override;
+	virtual Statement operator()(Assignment const& _assignment) override;
+	virtual Statement operator()(VariableDeclaration const& _varDecl) override;
+	virtual Statement operator()(If const& _if) override;
+	virtual Statement operator()(Switch const& _switch) override;
+	virtual Statement operator()(FunctionDefinition const&) override;
+	virtual Statement operator()(ForLoop const&) override;
+	virtual Statement operator()(Block const& _block) override;
+
+	virtual Expression translate(Expression const& _expression);
 	virtual Statement translate(Statement const& _statement);
 
 protected:
diff --git a/libjulia/optimiser/ASTWalker.cpp b/libjulia/optimiser/ASTWalker.cpp
index 0caef04e..499b4bf2 100644
--- a/libjulia/optimiser/ASTWalker.cpp
+++ b/libjulia/optimiser/ASTWalker.cpp
@@ -42,6 +42,11 @@ void ASTWalker::operator()(FunctionCall const& _funCall)
 	walkVector(_funCall.arguments | boost::adaptors::reversed);
 }
 
+void ASTWalker::operator()(ExpressionStatement const& _statement)
+{
+	boost::apply_visitor(*this, _statement.expression);
+}
+
 void ASTWalker::operator()(Assignment const& _assignment)
 {
 	for (auto const& name: _assignment.variableNames)
@@ -100,6 +105,11 @@ void ASTModifier::operator()(FunctionCall& _funCall)
 	walkVector(_funCall.arguments | boost::adaptors::reversed);
 }
 
+void ASTModifier::operator()(ExpressionStatement& _statement)
+{
+	boost::apply_visitor(*this, _statement.expression);
+}
+
 void ASTModifier::operator()(Assignment& _assignment)
 {
 	for (auto& name: _assignment.variableNames)
diff --git a/libjulia/optimiser/ASTWalker.h b/libjulia/optimiser/ASTWalker.h
index 8bd867d5..4652a353 100644
--- a/libjulia/optimiser/ASTWalker.h
+++ b/libjulia/optimiser/ASTWalker.h
@@ -47,6 +47,7 @@ public:
 	virtual void operator()(Identifier const&) {}
 	virtual void operator()(FunctionalInstruction const& _instr);
 	virtual void operator()(FunctionCall const& _funCall);
+	virtual void operator()(ExpressionStatement const& _statement);
 	virtual void operator()(Label const&) { solAssert(false, ""); }
 	virtual void operator()(StackAssignment const&) { solAssert(false, ""); }
 	virtual void operator()(Assignment const& _assignment);
@@ -77,6 +78,7 @@ public:
 	virtual void operator()(Identifier&) {}
 	virtual void operator()(FunctionalInstruction& _instr);
 	virtual void operator()(FunctionCall& _funCall);
+	virtual void operator()(ExpressionStatement& _statement);
 	virtual void operator()(Label&) { solAssert(false, ""); }
 	virtual void operator()(StackAssignment&) { solAssert(false, ""); }
 	virtual void operator()(Assignment& _assignment);
@@ -98,6 +100,10 @@ protected:
 	{
 		boost::apply_visitor(*this, _st);
 	}
+	virtual void visit(Expression& _e)
+	{
+		boost::apply_visitor(*this, _e);
+	}
 };
 
 }
diff --git a/libjulia/optimiser/Substitution.cpp b/libjulia/optimiser/Substitution.cpp
index a49f1f7a..668b6cb6 100644
--- a/libjulia/optimiser/Substitution.cpp
+++ b/libjulia/optimiser/Substitution.cpp
@@ -26,14 +26,14 @@ using namespace std;
 using namespace dev;
 using namespace dev::julia;
 
-Statement Substitution::translate(Statement const& _statement)
+Expression Substitution::translate(Expression const& _expression)
 {
-	if (_statement.type() == typeid(Identifier))
+	if (_expression.type() == typeid(Identifier))
 	{
-		string const& name = boost::get<Identifier>(_statement).name;
+		string const& name = boost::get<Identifier>(_expression).name;
 		if (m_substitutions.count(name))
 			// No recursive substitution
 			return ASTCopier().translate(*m_substitutions.at(name));
 	}
-	return ASTCopier::translate(_statement);
+	return ASTCopier::translate(_expression);
 }
diff --git a/libjulia/optimiser/Substitution.h b/libjulia/optimiser/Substitution.h
index 10bdf32e..313a08d7 100644
--- a/libjulia/optimiser/Substitution.h
+++ b/libjulia/optimiser/Substitution.h
@@ -33,18 +33,17 @@ namespace julia
 
 /**
  * Specific AST copier that replaces certain identifiers with expressions.
- * Only works on ASTs that are expressions.
  */
 class Substitution: public ASTCopier
 {
 public:
-	Substitution(std::map<std::string, Statement const*> const& _substitutions):
+	Substitution(std::map<std::string, Expression const*> const& _substitutions):
 		m_substitutions(_substitutions)
 	{}
-	virtual Statement translate(Statement const& _statement) override;
+	virtual Expression translate(Expression const& _expression) override;
 
 private:
-	std::map<std::string, Statement const*> const& m_substitutions;
+	std::map<std::string, Expression const*> const& m_substitutions;
 };
 
 }