Turn non-constant constants error into warning.

3 files changed, 8 insertions, 5 deletions

diff --git a/Changelog.md b/Changelog.md
index a80f23f4..ba802834 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -17,7 +17,7 @@ Bugfixes:
  * Type system: Detect cyclic dependencies between constants.
  * Type system: Disallow arrays with negative length.
  * Type system: Fix a crash related to invalid binary operators.
- * Type system: Only allow compile-time constants for constant state variables.
+ * Type system: Warn if constant state variables are not compile-time constants.
  * Type system: Disallow ``var`` declaration with empty tuple type.
  * Type system: Correctly convert function argument types to pointers for member functions.
  * Type system: Move privateness of constructor into AST itself.
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 41636db7..8e7ec29b 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -484,9 +484,10 @@ bool TypeChecker::visit(VariableDeclaration const& _variable)
 		if (!_variable.value())
 			typeError(_variable.location(), "Uninitialized \"constant\" variable.");
 		else if (!_variable.value()->annotation().isPure)
-			typeError(
+			warning(
 				_variable.value()->location(),
-				"Initial value for constant variable has to be compile-time constant."
+				"Initial value for constant variable has to be compile-time constant. "
+				"This will fail to compile with the next breaking version change."
 			);
 	}
 	if (!_variable.isStateVariable())
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 71fef32d..27791775 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -2180,7 +2180,8 @@ BOOST_AUTO_TEST_CASE(assigning_state_to_const_variable)
 			address constant x = msg.sender;
 		}
 	)";
-	CHECK_ERROR(text, TypeError, "Initial value for constant variable has to be compile-time constant.");
+	// Change to TypeError for 0.5.0.
+	CHECK_WARNING(text, "Initial value for constant variable has to be compile-time constant.");
 }
 
 BOOST_AUTO_TEST_CASE(constant_string_literal_disallows_assignment)
@@ -2207,7 +2208,8 @@ BOOST_AUTO_TEST_CASE(assign_constant_function_value_to_constant)
 			uint constant y = x();
 		}
 	)";
-	CHECK_ERROR(text, TypeError, "Initial value for constant variable has to be compile-time constant.");
+	// Change to TypeError for 0.5.0.
+	CHECK_WARNING(text, "Initial value for constant variable has to be compile-time constant.");
 }
 
 BOOST_AUTO_TEST_CASE(assignment_to_const_var_involving_conversion)