solidity-upgrade can now change now to block.timestamp

tools/solidityUpgrade/SourceTransform.h

@@ -267,6 +267,24 @@ public:
 
 		return "";
 	}
+
+	static std::string nowUpdate(langutil::SourceLocation const& _location)
+	{
+		std::regex nowRegex{"now"};
+
+		if (regex_search(_location.text(), nowRegex))
+		{
+			return regex_replace(_location.text(), nowRegex, "block.timestamp");
+		}
+		else
+			solAssert(
+				false,
+				LocationHelper() << "Could not fix: " << _location.text() << " at " << _location <<
+				"\nNeeds to be fixed manually."
+			);
+
+		return "";
+	}
 };
 
 }

tools/solidityUpgrade/SourceUpgrade.cpp

@@ -196,6 +196,8 @@ Allowed options)",
 				m_suite.activateModule(Module::VirtualFunction);
 			else if (module == "dotsyntax")
 				m_suite.activateModule(Module::DotSyntax);
+			else if (module == "now")
+				m_suite.activateModule(Module::NowKeyword);
 			else
 			{
 				error() << "Unknown upgrade module \"" + module + "\"" << endl;

tools/solidityUpgrade/SourceUpgrade.h

@@ -58,7 +58,8 @@ private:
 		AbstractContract,
 		OverridingFunction,
 		VirtualFunction,
-		DotSyntax
+		DotSyntax,
+		NowKeyword
 	};
 
 	/// Upgrade suite that hosts all available modules.
@@ -84,6 +85,8 @@ private:
 			/// Solidity 0.7.0
 			if (isActivated(Module::DotSyntax))
 				DotSyntax{m_changes}.analyze(_sourceUnit);
+			if (isActivated(Module::NowKeyword))
+				NowKeyword{m_changes}.analyze(_sourceUnit);
 		}
 
 		void activateModule(Module _module) { m_modules.insert(_module); }
@@ -103,7 +106,8 @@ private:
 			Module::AbstractContract,
 			Module::OverridingFunction,
 			Module::VirtualFunction,
-			Module::DotSyntax
+			Module::DotSyntax,
+			Module::NowKeyword
 		};
 	};
 

tools/solidityUpgrade/Upgrade070.cpp

@@ -40,3 +40,22 @@ void DotSyntax::endVisit(FunctionCall const& _functionCall)
 			);
 	}
 }
+
+void NowKeyword::endVisit(Identifier const& _identifier)
+{
+	IdentifierAnnotation& annotation = _identifier.annotation();
+
+	if (MagicVariableDeclaration const* magicVar
+		= dynamic_cast<MagicVariableDeclaration const*>(annotation.referencedDeclaration))
+	{
+		if (magicVar->type()->category() == Type::Category::Integer)
+		{
+			solAssert(_identifier.name() == "now", "");
+			m_changes.emplace_back(
+				UpgradeChange::Level::Safe,
+				_identifier.location(),
+				SourceTransform::nowUpdate(_identifier.location())
+			);
+		}
+	}
+}

tools/solidityUpgrade/Upgrade070.h

@@ -32,4 +32,13 @@ private:
 	void endVisit(frontend::FunctionCall const& _expression) override;
 };
 
+class NowKeyword: public AnalysisUpgrade
+{
+public:
+	using AnalysisUpgrade::AnalysisUpgrade;
+	void analyze(frontend::SourceUnit const& _sourceUnit) { _sourceUnit.accept(*this); }
+private:
+	void endVisit(frontend::Identifier const& _expression) override;
+};
+
 }