From aed6c22318dcc763342d434b2b85e125d1d02610 Mon Sep 17 00:00:00 2001
From: Harikrishnan Mulackal <webmail.hari@gmail.com>
Date: Tue, 5 May 2020 16:34:01 +0530
Subject: [PATCH] solidity-upgrade can now change now to block.timestamp

---
 docs/070-breaking-changes.rst           |  1 +
 docs/using-the-compiler.rst             |  6 ++++++
 tools/solidityUpgrade/SourceTransform.h | 18 ++++++++++++++++++
 tools/solidityUpgrade/SourceUpgrade.cpp |  2 ++
 tools/solidityUpgrade/SourceUpgrade.h   |  8 ++++++--
 tools/solidityUpgrade/Upgrade070.cpp    | 19 +++++++++++++++++++
 tools/solidityUpgrade/Upgrade070.h      |  9 +++++++++
 7 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/docs/070-breaking-changes.rst b/docs/070-breaking-changes.rst
index 1d8dd695d..f273dcd0b 100644
--- a/docs/070-breaking-changes.rst
+++ b/docs/070-breaking-changes.rst
@@ -15,3 +15,4 @@ This section gives detailed instructions on how to update prior code for every b
 
 * Change ``f.value(...)()`` to ``f{value: ...}()``. Similarly ``(new C).value(...)()`` to
   ``(new C){value: ...}()`` and ``f.gas(...)()`` to ``f{gas: ...}()``.
+* Change ``now`` to ``block.timestamp``.
diff --git a/docs/using-the-compiler.rst b/docs/using-the-compiler.rst
index e409323fa..08f817670 100644
--- a/docs/using-the-compiler.rst
+++ b/docs/using-the-compiler.rst
@@ -580,6 +580,12 @@ Available upgrade modules
 |                 |         | ``f{gas: ..., value: ...}()`` and                |
 |                 |         | ``(new C){value: ...}()``.                       |
 +-----------------+---------+--------------------------------------------------+
+| ``now``         | 0.7.0   | The ``now`` keyword is deprecated. Use           |
+|                 |         | ``block.timestamp`` instead.                     |
+|                 |         |                                                  |
+|                 |         |                                                  |
+|                 |         |                                                  |
++-----------------+---------+--------------------------------------------------+
 
 Please read :doc:`0.5.0 release notes <050-breaking-changes>`,
 :doc:`0.6.0 release notes <060-breaking-changes>` and
diff --git a/tools/solidityUpgrade/SourceTransform.h b/tools/solidityUpgrade/SourceTransform.h
index b9250ae6a..200c20e5b 100644
--- a/tools/solidityUpgrade/SourceTransform.h
+++ b/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 "";
+	}
 };
 
 }
diff --git a/tools/solidityUpgrade/SourceUpgrade.cpp b/tools/solidityUpgrade/SourceUpgrade.cpp
index 04f83eeee..6fffc074d 100644
--- a/tools/solidityUpgrade/SourceUpgrade.cpp
+++ b/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;
diff --git a/tools/solidityUpgrade/SourceUpgrade.h b/tools/solidityUpgrade/SourceUpgrade.h
index 9fb7a5ee2..8b82b310e 100644
--- a/tools/solidityUpgrade/SourceUpgrade.h
+++ b/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
 		};
 	};
 
diff --git a/tools/solidityUpgrade/Upgrade070.cpp b/tools/solidityUpgrade/Upgrade070.cpp
index c38ae2b97..8e921ce11 100644
--- a/tools/solidityUpgrade/Upgrade070.cpp
+++ b/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())
+			);
+		}
+	}
+}
diff --git a/tools/solidityUpgrade/Upgrade070.h b/tools/solidityUpgrade/Upgrade070.h
index 29d689f97..bfa07ce51 100644
--- a/tools/solidityUpgrade/Upgrade070.h
+++ b/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;
+};
+
 }