Give min and max values in warning message.

2 files changed, 29 insertions, 3 deletions

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 1c91a2b0..b276a2d4 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -964,9 +964,17 @@ bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 				{
 					int numBits = type->numBits();
 					bool isSigned = type->isSigned();
+					string minValue;
+					string maxValue;
 					if (isSigned)
+					{
 						numBits--;
-					extension = ", which can hold values up to " + string((u256(1) << numBits) - 1);
+						minValue = "-" + bigint(bigint(1) << numBits).str();
+					}
+					else
+						minValue = "0";
+					maxValue = bigint((bigint(1) << numBits) - 1).str();
+					extension = ", which can hold values between " + minValue + " and " + maxValue;
 				}
 				else
 					solAssert(dynamic_cast<FixedPointType const*>(var.annotation().type.get()), "Unknown type.");
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 3d6104db..169b33d1 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -1798,14 +1798,32 @@ BOOST_AUTO_TEST_CASE(warn_var_from_zero)
 			}
 		}
 	)";
-	CHECK_WARNING(sourceCode, "uint8, which can hold");
+	CHECK_WARNING(sourceCode, "uint8, which can hold values between 0 and 255");
+	sourceCode = R"(
+		contract test {
+			function f() {
+				var i = 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff;
+				i;
+			}
+		}
+	)";
+	CHECK_WARNING(sourceCode, "uint256, which can hold values between 0 and 115792089237316195423570985008687907853269984665640564039457584007913129639935");
+	sourceCode = R"(
+		contract test {
+			function f() {
+				var i = -2;
+				i;
+			}
+		}
+	)";
+	CHECK_WARNING(sourceCode, "int8, which can hold values between -128 and 127");
 	sourceCode = R"(
 		 contract test {
 			 function f() {
 				 for (var i = 0; i < msg.data.length; i++) { }
 			 }
 		 }
-	 )";
+	)";
 	CHECK_WARNING(sourceCode, "uint8, which can hold");
 }