Merge pull request #326 from guanqun/cond-expr

support conditional expression _ ? _ : _

17 files changed, 586 insertions, 7 deletions

diff --git a/docs/control-structures.rst b/docs/control-structures.rst
index c833fbfc..4becfcf1 100644
--- a/docs/control-structures.rst
+++ b/docs/control-structures.rst
@@ -9,7 +9,7 @@ Control Structures
 
 Most of the control structures from C/JavaScript are available in Solidity
 except for `switch` and `goto`. So
-there is: `if`, `else`, `while`, `for`, `break`, `continue`, `return`, with
+there is: `if`, `else`, `while`, `for`, `break`, `continue`, `return`, `? :`, with
 the usual semantics known from C / JavaScript.
 
 Parentheses can *not* be omitted for conditionals, but curly brances can be omitted
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 69357043..0d74ddba 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -744,6 +744,43 @@ void TypeChecker::endVisit(ExpressionStatement const& _statement)
 			typeError(_statement.expression().location(), "Invalid integer constant.");
 }
 
+bool TypeChecker::visit(Conditional const& _conditional)
+{
+	expectType(_conditional.condition(), BoolType());
+
+	_conditional.trueExpression().accept(*this);
+	_conditional.falseExpression().accept(*this);
+
+	TypePointer trueType = type(_conditional.trueExpression())->mobileType();
+	TypePointer falseType = type(_conditional.falseExpression())->mobileType();
+
+	TypePointer commonType = Type::commonType(trueType, falseType);
+	if (!commonType)
+	{
+		typeError(
+				_conditional.location(),
+				"True expression's type " +
+				trueType->toString() +
+				" doesn't match false expression's type " +
+				falseType->toString() +
+				"."
+		);
+		// even we can't find a common type, we have to set a type here,
+		// otherwise the upper statement will not be able to check the type.
+		commonType = trueType;
+	}
+
+	_conditional.annotation().type = commonType;
+
+	if (_conditional.annotation().lValueRequested)
+		typeError(
+				_conditional.location(),
+				"Conditional expression as left value is not supported yet."
+		);
+
+	return false;
+}
+
 bool TypeChecker::visit(Assignment const& _assignment)
 {
 	requireLValue(_assignment.leftHandSide());
diff --git a/libsolidity/analysis/TypeChecker.h b/libsolidity/analysis/TypeChecker.h
index 7829a23d..b884db49 100644
--- a/libsolidity/analysis/TypeChecker.h
+++ b/libsolidity/analysis/TypeChecker.h
@@ -90,6 +90,7 @@ private:
 	virtual void endVisit(Return const& _return) override;
 	virtual bool visit(VariableDeclarationStatement const& _variable) override;
 	virtual void endVisit(ExpressionStatement const& _statement) override;
+	virtual bool visit(Conditional const& _conditional) override;
 	virtual bool visit(Assignment const& _assignment) override;
 	virtual bool visit(TupleExpression const& _tuple) override;
 	virtual void endVisit(BinaryOperation const& _operation) override;
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index 4baf95d3..e1063467 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -1119,6 +1119,33 @@ public:
 	ExpressionAnnotation& annotation() const override;
 };
 
+class Conditional: public Expression
+{
+public:
+	Conditional(
+		SourceLocation const& _location,
+		ASTPointer<Expression> const& _condition,
+		ASTPointer<Expression> const& _trueExpression,
+		ASTPointer<Expression> const& _falseExpression
+	):
+		Expression(_location),
+		m_condition(_condition),
+		m_trueExpression(_trueExpression),
+		m_falseExpression(_falseExpression)
+	{}
+	virtual void accept(ASTVisitor& _visitor) override;
+	virtual void accept(ASTConstVisitor& _visitor) const override;
+
+	Expression const& condition() const { return *m_condition; }
+	Expression const& trueExpression() const { return *m_trueExpression; }
+	Expression const& falseExpression() const { return *m_falseExpression; }
+
+private:
+	ASTPointer<Expression> m_condition;
+	ASTPointer<Expression> m_trueExpression;
+	ASTPointer<Expression> m_falseExpression;
+};
+
 /// Assignment, can also be a compound assignment.
 /// Examples: (a = 7 + 8) or (a *= 2)
 class Assignment: public Expression
diff --git a/libsolidity/ast/ASTForward.h b/libsolidity/ast/ASTForward.h
index 6aaa77ce..dad2b2e2 100644
--- a/libsolidity/ast/ASTForward.h
+++ b/libsolidity/ast/ASTForward.h
@@ -69,6 +69,7 @@ class Throw;
 class VariableDeclarationStatement;
 class ExpressionStatement;
 class Expression;
+class Conditional;
 class Assignment;
 class TupleExpression;
 class UnaryOperation;
diff --git a/libsolidity/ast/ASTJsonConverter.cpp b/libsolidity/ast/ASTJsonConverter.cpp
index 377fa7e6..df836afe 100644
--- a/libsolidity/ast/ASTJsonConverter.cpp
+++ b/libsolidity/ast/ASTJsonConverter.cpp
@@ -217,6 +217,12 @@ bool ASTJsonConverter::visit(ExpressionStatement const&)
 	return true;
 }
 
+bool ASTJsonConverter::visit(Conditional const&)
+{
+	addJsonNode("Conditional", {}, true);
+	return true;
+}
+
 bool ASTJsonConverter::visit(Assignment const& _node)
 {
 	addJsonNode("Assignment",
@@ -397,6 +403,11 @@ void ASTJsonConverter::endVisit(ExpressionStatement const&)
 	goUp();
 }
 
+void ASTJsonConverter::endVisit(Conditional const&)
+{
+	goUp();
+}
+
 void ASTJsonConverter::endVisit(Assignment const&)
 {
 	goUp();
diff --git a/libsolidity/ast/ASTJsonConverter.h b/libsolidity/ast/ASTJsonConverter.h
index de891cc6..b7fc84e9 100644
--- a/libsolidity/ast/ASTJsonConverter.h
+++ b/libsolidity/ast/ASTJsonConverter.h
@@ -67,6 +67,7 @@ public:
 	bool visit(Throw const& _node) override;
 	bool visit(VariableDeclarationStatement const& _node) override;
 	bool visit(ExpressionStatement const& _node) override;
+	bool visit(Conditional const& _node) override;
 	bool visit(Assignment const& _node) override;
 	bool visit(TupleExpression const& _node) override;
 	bool visit(UnaryOperation const& _node) override;
@@ -99,6 +100,7 @@ public:
 	void endVisit(Throw const&) override;
 	void endVisit(VariableDeclarationStatement const&) override;
 	void endVisit(ExpressionStatement const&) override;
+	void endVisit(Conditional const&) override;
 	void endVisit(Assignment const&) override;
 	void endVisit(TupleExpression const&) override;
 	void endVisit(UnaryOperation const&) override;
diff --git a/libsolidity/ast/ASTPrinter.cpp b/libsolidity/ast/ASTPrinter.cpp
index d4f13e47..bc981f7d 100644
--- a/libsolidity/ast/ASTPrinter.cpp
+++ b/libsolidity/ast/ASTPrinter.cpp
@@ -248,6 +248,14 @@ bool ASTPrinter::visit(ExpressionStatement const& _node)
 	return goDeeper();
 }
 
+bool ASTPrinter::visit(Conditional const& _node)
+{
+	writeLine("Conditional");
+	printType(_node);
+	printSourcePart(_node);
+	return goDeeper();
+}
+
 bool ASTPrinter::visit(Assignment const& _node)
 {
 	writeLine(string("Assignment using operator ") + Token::toString(_node.assignmentOperator()));
@@ -480,6 +488,11 @@ void ASTPrinter::endVisit(ExpressionStatement const&)
 	m_indentation--;
 }
 
+void ASTPrinter::endVisit(Conditional const&)
+{
+	m_indentation--;
+}
+
 void ASTPrinter::endVisit(Assignment const&)
 {
 	m_indentation--;
diff --git a/libsolidity/ast/ASTPrinter.h b/libsolidity/ast/ASTPrinter.h
index d9b5e252..334fefc7 100644
--- a/libsolidity/ast/ASTPrinter.h
+++ b/libsolidity/ast/ASTPrinter.h
@@ -75,6 +75,7 @@ public:
 	bool visit(Throw const& _node) override;
 	bool visit(VariableDeclarationStatement const& _node) override;
 	bool visit(ExpressionStatement const& _node) override;
+	bool visit(Conditional const& _node) override;
 	bool visit(Assignment const& _node) override;
 	bool visit(TupleExpression const& _node) override;
 	bool visit(UnaryOperation const& _node) override;
@@ -115,6 +116,7 @@ public:
 	void endVisit(Throw const&) override;
 	void endVisit(VariableDeclarationStatement const&) override;
 	void endVisit(ExpressionStatement const&) override;
+	void endVisit(Conditional const&) override;
 	void endVisit(Assignment const&) override;
 	void endVisit(TupleExpression const&) override;
 	void endVisit(UnaryOperation const&) override;
diff --git a/libsolidity/ast/ASTVisitor.h b/libsolidity/ast/ASTVisitor.h
index f04d9682..625f395d 100644
--- a/libsolidity/ast/ASTVisitor.h
+++ b/libsolidity/ast/ASTVisitor.h
@@ -73,6 +73,7 @@ public:
 	virtual bool visit(Throw& _node) { return visitNode(_node); }
 	virtual bool visit(VariableDeclarationStatement& _node) { return visitNode(_node); }
 	virtual bool visit(ExpressionStatement& _node) { return visitNode(_node); }
+	virtual bool visit(Conditional& _node) { return visitNode(_node); }
 	virtual bool visit(Assignment& _node) { return visitNode(_node); }
 	virtual bool visit(TupleExpression& _node) { return visitNode(_node); }
 	virtual bool visit(UnaryOperation& _node) { return visitNode(_node); }
@@ -115,6 +116,7 @@ public:
 	virtual void endVisit(Throw& _node) { endVisitNode(_node); }
 	virtual void endVisit(VariableDeclarationStatement& _node) { endVisitNode(_node); }
 	virtual void endVisit(ExpressionStatement& _node) { endVisitNode(_node); }
+	virtual void endVisit(Conditional& _node) { endVisitNode(_node); }
 	virtual void endVisit(Assignment& _node) { endVisitNode(_node); }
 	virtual void endVisit(TupleExpression& _node) { endVisitNode(_node); }
 	virtual void endVisit(UnaryOperation& _node) { endVisitNode(_node); }
@@ -169,6 +171,7 @@ public:
 	virtual bool visit(Throw const& _node) { return visitNode(_node); }
 	virtual bool visit(VariableDeclarationStatement const& _node) { return visitNode(_node); }
 	virtual bool visit(ExpressionStatement const& _node) { return visitNode(_node); }
+	virtual bool visit(Conditional const& _node) { return visitNode(_node); }
 	virtual bool visit(Assignment const& _node) { return visitNode(_node); }
 	virtual bool visit(TupleExpression const& _node) { return visitNode(_node); }
 	virtual bool visit(UnaryOperation const& _node) { return visitNode(_node); }
@@ -211,6 +214,7 @@ public:
 	virtual void endVisit(Throw const& _node) { endVisitNode(_node); }
 	virtual void endVisit(VariableDeclarationStatement const& _node) { endVisitNode(_node); }
 	virtual void endVisit(ExpressionStatement const& _node) { endVisitNode(_node); }
+	virtual void endVisit(Conditional const& _node) { endVisitNode(_node); }
 	virtual void endVisit(Assignment const& _node) { endVisitNode(_node); }
 	virtual void endVisit(TupleExpression const& _node) { endVisitNode(_node); }
 	virtual void endVisit(UnaryOperation const& _node) { endVisitNode(_node); }
diff --git a/libsolidity/ast/AST_accept.h b/libsolidity/ast/AST_accept.h
index 61370c55..dee9d5b1 100644
--- a/libsolidity/ast/AST_accept.h
+++ b/libsolidity/ast/AST_accept.h
@@ -551,6 +551,28 @@ void VariableDeclarationStatement::accept(ASTConstVisitor& _visitor) const
 	_visitor.endVisit(*this);
 }
 
+void Conditional::accept(ASTVisitor& _visitor)
+{
+	if (_visitor.visit(*this))
+	{
+		m_condition->accept(_visitor);
+		m_trueExpression->accept(_visitor);
+		m_falseExpression->accept(_visitor);
+	}
+	_visitor.endVisit(*this);
+}
+
+void Conditional::accept(ASTConstVisitor& _visitor) const
+{
+	if (_visitor.visit(*this))
+	{
+		m_condition->accept(_visitor);
+		m_trueExpression->accept(_visitor);
+		m_falseExpression->accept(_visitor);
+	}
+	_visitor.endVisit(*this);
+}
+
 void Assignment::accept(ASTVisitor& _visitor)
 {
 	if (_visitor.visit(*this))
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 040217da..9536c727 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -176,6 +176,22 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 	m_context.appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
 }
 
+bool ExpressionCompiler::visit(Conditional const& _condition)
+{
+	CompilerContext::LocationSetter locationSetter(m_context, _condition);
+	_condition.condition().accept(*this);
+	eth::AssemblyItem trueTag = m_context.appendConditionalJump();
+	_condition.falseExpression().accept(*this);
+	utils().convertType(*_condition.falseExpression().annotation().type, *_condition.annotation().type);
+	eth::AssemblyItem endTag = m_context.appendJumpToNew();
+	m_context << trueTag;
+	m_context.adjustStackOffset(-_condition.annotation().type->sizeOnStack());
+	_condition.trueExpression().accept(*this);
+	utils().convertType(*_condition.trueExpression().annotation().type, *_condition.annotation().type);
+	m_context << endTag;
+	return false;
+}
+
 bool ExpressionCompiler::visit(Assignment const& _assignment)
 {
 	CompilerContext::LocationSetter locationSetter(m_context, _assignment);
diff --git a/libsolidity/codegen/ExpressionCompiler.h b/libsolidity/codegen/ExpressionCompiler.h
index 379aa65a..f00b24e8 100644
--- a/libsolidity/codegen/ExpressionCompiler.h
+++ b/libsolidity/codegen/ExpressionCompiler.h
@@ -71,6 +71,7 @@ public:
 	void appendConstStateVariableAccessor(const VariableDeclaration& _varDecl);
 
 private:
+	virtual bool visit(Conditional const& _condition) override;
 	virtual bool visit(Assignment const& _assignment) override;
 	virtual bool visit(TupleExpression const& _tuple) override;
 	virtual bool visit(UnaryOperation const& _unaryOperation) override;
diff --git a/libsolidity/parsing/Parser.cpp b/libsolidity/parsing/Parser.cpp
index 4ac3381c..d9ec1a49 100644
--- a/libsolidity/parsing/Parser.cpp
+++ b/libsolidity/parsing/Parser.cpp
@@ -932,13 +932,26 @@ ASTPointer<Expression> Parser::parseExpression(
 )
 {
 	ASTPointer<Expression> expression = parseBinaryExpression(4, _lookAheadIndexAccessStructure);
-	if (!Token::isAssignmentOp(m_scanner->currentToken()))
+	if (Token::isAssignmentOp(m_scanner->currentToken()))
+	{
+		Token::Value assignmentOperator = expectAssignmentOperator();
+		ASTPointer<Expression> rightHandSide = parseExpression();
+		ASTNodeFactory nodeFactory(*this, expression);
+		nodeFactory.setEndPositionFromNode(rightHandSide);
+		return nodeFactory.createNode<Assignment>(expression, assignmentOperator, rightHandSide);
+	}
+	else if (m_scanner->currentToken() == Token::Value::Conditional)
+	{
+		m_scanner->next();
+		ASTPointer<Expression> trueExpression = parseExpression();
+		expectToken(Token::Colon);
+		ASTPointer<Expression> falseExpression = parseExpression();
+		ASTNodeFactory nodeFactory(*this, expression);
+		nodeFactory.setEndPositionFromNode(falseExpression);
+		return nodeFactory.createNode<Conditional>(expression, trueExpression, falseExpression);
+	}
+	else
 		return expression;
-	Token::Value assignmentOperator = expectAssignmentOperator();
-	ASTPointer<Expression> rightHandSide = parseExpression();
-	ASTNodeFactory nodeFactory(*this, expression);
-	nodeFactory.setEndPositionFromNode(rightHandSide);
-	return nodeFactory.createNode<Assignment>(expression, assignmentOperator, rightHandSide);
 }
 
 ASTPointer<Expression> Parser::parseBinaryExpression(
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 3ef5ebbe..73e2d662 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -86,6 +86,192 @@ BOOST_AUTO_TEST_CASE(exp_operator_const_signed)
 	BOOST_CHECK(callContractFunction("f()", bytes()) == toBigEndian(u256(-8)));
 }
 
+BOOST_AUTO_TEST_CASE(conditional_expression_true_literal)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f() returns(uint d) {
+				return true ? 5 : 10;
+ 			}
+		})";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f()", bytes()) == toBigEndian(u256(5)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_false_literal)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f() returns(uint d) {
+				return false ? 5 : 10;
+ 			}
+		})";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f()", bytes()) == toBigEndian(u256(10)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_multiple)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f(uint x) returns(uint d) {
+				return x > 100 ? 
+							x > 1000 ? 1000 : 100
+							:
+							x > 50 ? 50 : 10;
+ 			}
+		})";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(uint256)", u256(1001)) == toBigEndian(u256(1000)));
+	BOOST_CHECK(callContractFunction("f(uint256)", u256(500)) == toBigEndian(u256(100)));
+	BOOST_CHECK(callContractFunction("f(uint256)", u256(80)) == toBigEndian(u256(50)));
+	BOOST_CHECK(callContractFunction("f(uint256)", u256(40)) == toBigEndian(u256(10)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_with_return_values)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f(bool cond, uint v) returns (uint a, uint b) {
+				cond ? a = v : b = v;
+ 			}
+		})";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool,uint256)", true, u256(20)) == encodeArgs(u256(20), u256(0)));
+	BOOST_CHECK(callContractFunction("f(bool,uint256)", false, u256(20)) == encodeArgs(u256(0), u256(20)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_storage_memory_1)
+{
+	char const* sourceCode = R"(
+		contract test {
+			bytes2[2] data1;
+			function f(bool cond) returns (uint) {
+				bytes2[2] memory x;
+				x[0] = "aa";
+				bytes2[2] memory y;
+				y[0] = "bb";
+
+				data1 = cond ? x : y;
+
+				uint ret = 0;
+				if (data1[0] == "aa")
+				{
+					ret = 1;
+				}
+
+				if (data1[0] == "bb")
+				{
+					ret = 2;
+				}
+
+				return ret;
+			}    
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool)", true) == encodeArgs(u256(1)));
+	BOOST_CHECK(callContractFunction("f(bool)", false) == encodeArgs(u256(2)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_storage_memory_2)
+{
+	char const* sourceCode = R"(
+		contract test {
+			bytes2[2] data1;
+			function f(bool cond) returns (uint) {
+				data1[0] = "cc";
+
+				bytes2[2] memory x;
+				bytes2[2] memory y;
+				y[0] = "bb";
+
+				x = cond ? y : data1;
+
+				uint ret = 0;
+				if (x[0] == "bb")
+				{
+					ret = 1;
+				}
+
+				if (x[0] == "cc")
+				{
+					ret = 2;
+				}
+
+				return ret;
+			}    
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool)", true) == encodeArgs(u256(1)));
+	BOOST_CHECK(callContractFunction("f(bool)", false) == encodeArgs(u256(2)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_different_types)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f(bool cond) returns (uint) {
+				uint8 x = 0xcd;
+				uint16 y = 0xabab;
+				return cond ? x : y;
+			}    
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool)", true) == encodeArgs(u256(0xcd)));
+	BOOST_CHECK(callContractFunction("f(bool)", false) == encodeArgs(u256(0xabab)));
+}
+
+/* let's add this back when I figure out the correct type conversion.
+BOOST_AUTO_TEST_CASE(conditional_expression_string_literal)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f(bool cond) returns (bytes32) {
+				return cond ? "true" : "false";
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool)", true) == encodeArgs(string("true", 4)));
+	BOOST_CHECK(callContractFunction("f(bool)", false) == encodeArgs(string("false", 5)));
+}
+*/
+
+BOOST_AUTO_TEST_CASE(conditional_expression_tuples)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function f(bool cond) returns (uint, uint) {
+				return cond ? (1, 2) : (3, 4);
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool)", true) == encodeArgs(u256(1), u256(2)));
+	BOOST_CHECK(callContractFunction("f(bool)", false) == encodeArgs(u256(3), u256(4)));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_functions)
+{
+	char const* sourceCode = R"(
+		contract test {
+			function x() returns (uint) { return 1; }
+			function y() returns (uint) { return 2; }
+
+			function f(bool cond) returns (uint) {
+				var z = cond ? x : y;
+				return z();
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("f(bool)", true) == encodeArgs(u256(1)));
+	BOOST_CHECK(callContractFunction("f(bool)", false) == encodeArgs(u256(2)));
+}
+
 BOOST_AUTO_TEST_CASE(recursive_calls)
 {
 	char const* sourceCode = "contract test {\n"
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index c8e901e4..820fd7d0 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -2960,6 +2960,182 @@ BOOST_AUTO_TEST_CASE(continue_not_in_loop_2)
 	BOOST_CHECK(expectError(text) == Error::Type::SyntaxError);
 }
 
+BOOST_AUTO_TEST_CASE(invalid_different_types_for_conditional_expression)
+{
+	char const* text = R"(
+		contract C {
+			function f() {
+				true ? true : 2;
+			}
+		}
+	)";
+	BOOST_CHECK(expectError(text) == Error::Type::TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(left_value_in_conditional_expression_not_supported_yet)
+{
+	char const* text = R"(
+		contract C {
+			function f() {
+				uint x;
+				uint y;
+				(true ? x : y) = 1;
+			}
+		}
+	)";
+	BOOST_CHECK(expectError(text) == Error::Type::TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_with_different_struct)
+{
+	char const* text = R"(
+		contract C {
+			struct s1 {
+				uint x;
+			}
+			struct s2 {
+				uint x;
+			}
+			function f() {
+				s1 x;
+				s2 y;
+				true ? x : y;
+			}
+		}
+	)";
+	BOOST_CHECK(expectError(text) == Error::Type::TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_with_different_function_type)
+{
+	char const* text = R"(
+		contract C {
+			function x(bool) {}
+			function y() {}
+
+			function f() {
+				true ? x : y;
+			}
+		}
+	)";
+	BOOST_CHECK(expectError(text) == Error::Type::TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_with_different_enum)
+{
+	char const* text = R"(
+		contract C {
+			enum small { A, B, C, D }
+			enum big { A, B, C, D }
+
+			function f() {
+				small x;
+				big y;
+
+				true ? x : y;
+			}
+		}
+	)";
+	BOOST_CHECK(expectError(text) == Error::Type::TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(conditional_expression_with_different_mapping)
+{
+	char const* text = R"(
+		contract C {
+			mapping(uint8 => uint8) table1;
+			mapping(uint32 => uint8) table2;
+
+			function f() {
+				true ? table1 : table2;
+			}
+		}
+	)";
+	BOOST_CHECK(expectError(text) == Error::Type::TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(conditional_with_all_types)
+{
+	char const* text = R"(
+		contract C {
+			struct s1 {
+				uint x;
+			}
+			s1 struct_x;
+			s1 struct_y;
+
+			function fun_x() {}
+			function fun_y() {}
+
+			enum small { A, B, C, D }
+
+			mapping(uint8 => uint8) table1;
+			mapping(uint8 => uint8) table2;
+
+			function f() {
+				// integers
+				uint x;
+				uint y;
+				true ? x : y;
+
+				// integer constants
+				true ? 1 : 3;
+
+				// string literal
+				true ? "hello" : "world";
+
+				// bool
+				true ? true : false;
+
+				// real is not there yet.
+
+				// array
+				byte[2] memory a;
+				byte[2] memory b;
+				true ? a : b;
+
+				bytes memory e;
+				bytes memory f;
+				true ? e : f;
+
+				// fixed bytes
+				bytes2 c;
+				bytes2 d;
+				true ? c : d;
+
+				// contract doesn't fit in here
+
+				// struct
+				true ? struct_x : struct_y;
+
+				// function
+				true ? fun_x : fun_y;
+
+				// enum
+				small enum_x;
+				small enum_y;
+				true ? enum_x : enum_y;
+
+				// tuple
+				true ? (1, 2) : (3, 4);
+
+				// mapping
+				true ? table1 : table2;
+
+				// typetype
+				true ? uint32(1) : uint32(2);
+
+				// modifier doesn't fit in here
+
+				// magic doesn't fit in here
+
+				// module doesn't fit in here
+			}
+		}
+	)";
+	BOOST_CHECK(success(text));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }
diff --git a/test/libsolidity/SolidityParser.cpp b/test/libsolidity/SolidityParser.cpp
index 8e0bf77e..055fae49 100644
--- a/test/libsolidity/SolidityParser.cpp
+++ b/test/libsolidity/SolidityParser.cpp
@@ -1111,6 +1111,73 @@ BOOST_AUTO_TEST_CASE(inline_array_empty_cells_check_without_lvalue)
 	BOOST_CHECK(!successParse(text));
 }
 
+BOOST_AUTO_TEST_CASE(conditional_true_false_literal)
+{
+	char const* text = R"(
+		contract A {
+			function f() {
+				uint x = true ? 1 : 0;
+				uint y = false ? 0 : 1;
+			}
+		}
+	)";
+	BOOST_CHECK(successParse(text));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_with_constants)
+{
+	char const* text = R"(
+		contract A {
+			function f() {
+				uint x = 3 > 0 ? 3 : 0;
+				uint y = (3 > 0) ? 3 : 0;
+			}
+		}
+	)";
+	BOOST_CHECK(successParse(text));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_with_variables)
+{
+	char const* text = R"(
+		contract A {
+			function f() {
+				uint x = 3;
+				uint y = 1;
+				uint z = (x > y) ? x : y;
+				uint w = x > y ? x : y;
+			}
+		}
+	)";
+	BOOST_CHECK(successParse(text));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_multiple)
+{
+	char const* text = R"(
+		contract A {
+			function f() {
+				uint x = 3 < 0 ? 2 > 1 ? 2 : 1 : 7 > 2 ? 7 : 6;
+			}
+		}
+	)";
+	BOOST_CHECK(successParse(text));
+}
+
+BOOST_AUTO_TEST_CASE(conditional_with_assignment)
+{
+	char const* text = R"(
+		contract A {
+			function f() {
+				uint y = 1;
+				uint x = 3 < 0 ? x = 3 : 6;
+				true ? x = 3 : 4;
+			}
+		}
+	)";
+	BOOST_CHECK(successParse(text));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }