From 0f8ad1d68f60270fb22057e787ff689318c31fa9 Mon Sep 17 00:00:00 2001
From: Federico Bond <federicobond@gmail.com>
Date: Thu, 15 Jun 2017 12:36:14 -0300
Subject: [PATCH] Fix segmentation fault with constant function parameters

---
 Changelog.md                                  |  1 +
 libsolidity/analysis/TypeChecker.cpp          |  9 ++++++++-
 .../SolidityNameAndTypeResolution.cpp         | 20 +++++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/Changelog.md b/Changelog.md
index 0fb2fe5ce..4bf85d5f7 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -16,6 +16,7 @@ Bugfixes:
  * Fixed crash concerning non-callable types.
  * Unused variable warnings no longer issued for variables used inside inline assembly.
  * Inline Assembly: Enforce function arguments when parsing functional instructions.
+ * Fixed segfault with constant function parameters
 
 ### 0.4.11 (2017-05-03)
 
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 2a8d1ff6a..4194e1c25 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -463,6 +463,8 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 			m_errorReporter.typeError(var->location(), "Type is required to live outside storage.");
 		if (_function.visibility() >= FunctionDefinition::Visibility::Public && !(type(*var)->interfaceType(isLibraryFunction)))
 			m_errorReporter.fatalTypeError(var->location(), "Internal type is not allowed for public or external functions.");
+
+		var->accept(*this);
 	}
 	for (ASTPointer<ModifierInvocation> const& modifier: _function.modifiers())
 		visitManually(
@@ -487,7 +489,12 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 
 bool TypeChecker::visit(VariableDeclaration const& _variable)
 {
-	if (m_scope->contractKind() == ContractDefinition::ContractKind::Interface)
+	// Forbid any variable declarations inside interfaces unless they are part of
+	// a function's input/output parameters.
+	if (
+		m_scope->contractKind() == ContractDefinition::ContractKind::Interface
+		&& !_variable.isCallableParameter()
+	)
 		m_errorReporter.typeError(_variable.location(), "Variables cannot be declared in interfaces.");
 
 	// Variables can be declared without type (with "var"), in which case the first assignment
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 0b3cb481b..c4b1250f9 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -1597,6 +1597,16 @@ BOOST_AUTO_TEST_CASE(empty_name_input_parameter)
 	CHECK_SUCCESS(text);
 }
 
+BOOST_AUTO_TEST_CASE(constant_input_parameter)
+{
+	char const* text = R"(
+		contract test {
+			function f(uint[] constant a) { }
+		}
+	)";
+	CHECK_ERROR_ALLOW_MULTI(text, TypeError, "Illegal use of \"constant\" specifier.");
+}
+
 BOOST_AUTO_TEST_CASE(empty_name_return_parameter)
 {
 	char const* text = R"(
@@ -5582,6 +5592,16 @@ BOOST_AUTO_TEST_CASE(interface_variables)
 	CHECK_ERROR(text, TypeError, "Variables cannot be declared in interfaces");
 }
 
+BOOST_AUTO_TEST_CASE(interface_function_parameters)
+{
+	char const* text = R"(
+		interface I {
+			function f(uint a) returns(bool);
+		}
+	)";
+	success(text);
+}
+
 BOOST_AUTO_TEST_CASE(interface_enums)
 {
 	char const* text = R"(