Merge pull request #2904 from ethereum/viewPure5

Enforce view with error for experimental 0.5.0.

4 files changed, 35 insertions, 11 deletions

diff --git a/Changelog.md b/Changelog.md
index cbecb3cd..e46a7c2f 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -10,6 +10,7 @@ Features:
  * Type Checker: Greatly reduce the number of duplicate errors shown for duplicate constructors and functions.
  * Type Checker: Warn on using literals as tight packing parameters in ``keccak256``, ``sha3``, ``sha256`` and ``ripemd160``.
  * Type Checker: Enforce ``view`` and ``pure``.
+ * Type Checker: Enforce ``view`` / ``constant`` with error as experimental 0.5.0 feature.
 
 Bugfixes:
  * ABI JSON: Include all overloaded events.
diff --git a/libsolidity/analysis/ViewPureChecker.cpp b/libsolidity/analysis/ViewPureChecker.cpp
index 8f9d41c9..7f28c7d2 100644
--- a/libsolidity/analysis/ViewPureChecker.cpp
+++ b/libsolidity/analysis/ViewPureChecker.cpp
@@ -20,6 +20,7 @@
 #include <libevmasm/SemanticInformation.h>
 
 #include <libsolidity/inlineasm/AsmData.h>
+#include <libsolidity/ast/ExperimentalFeatures.h>
 
 #include <functional>
 
@@ -102,22 +103,31 @@ private:
 
 bool ViewPureChecker::check()
 {
-	vector<ContractDefinition const*> contracts;
+	// The bool means "enforce view with errors".
+	map<ContractDefinition const*, bool> contracts;
 
 	for (auto const& node: m_ast)
 	{
 		SourceUnit const* source = dynamic_cast<SourceUnit const*>(node.get());
 		solAssert(source, "");
-		contracts += source->filteredNodes<ContractDefinition>(source->nodes());
+		bool enforceView = source->annotation().experimentalFeatures.count(ExperimentalFeature::V050);
+		for (ContractDefinition const* c: source->filteredNodes<ContractDefinition>(source->nodes()))
+			contracts[c] = enforceView;
 	}
 
 	// Check modifiers first to infer their state mutability.
-	for (auto const* contract: contracts)
-		for (ModifierDefinition const* mod: contract->functionModifiers())
+	for (auto const& contract: contracts)
+	{
+		m_enforceViewWithError = contract.second;
+		for (ModifierDefinition const* mod: contract.first->functionModifiers())
 			mod->accept(*this);
+	}
 
-	for (auto const* contract: contracts)
-		contract->accept(*this);
+	for (auto const& contract: contracts)
+	{
+		m_enforceViewWithError = contract.second;
+		contract.first->accept(*this);
+	}
 
 	return !m_errors;
 }
@@ -223,16 +233,18 @@ void ViewPureChecker::reportMutability(StateMutability _mutability, SourceLocati
 		else
 			solAssert(false, "");
 
-		if (m_currentFunction->stateMutability() == StateMutability::View)
-			// TODO Change this to error with 0.5.0
+		solAssert(
+			m_currentFunction->stateMutability() == StateMutability::View ||
+			m_currentFunction->stateMutability() == StateMutability::Pure,
+			""
+		);
+		if (!m_enforceViewWithError && m_currentFunction->stateMutability() == StateMutability::View)
 			m_errorReporter.warning(_location, text);
-		else if (m_currentFunction->stateMutability() == StateMutability::Pure)
+		else
 		{
 			m_errors = true;
 			m_errorReporter.typeError(_location, text);
 		}
-		else
-			solAssert(false, "");
 	}
 	if (_mutability > m_currentBestMutability)
 		m_currentBestMutability = _mutability;
diff --git a/libsolidity/analysis/ViewPureChecker.h b/libsolidity/analysis/ViewPureChecker.h
index ae303533..fec060b6 100644
--- a/libsolidity/analysis/ViewPureChecker.h
+++ b/libsolidity/analysis/ViewPureChecker.h
@@ -70,6 +70,7 @@ private:
 	ErrorReporter& m_errorReporter;
 
 	bool m_errors = false;
+	bool m_enforceViewWithError = false;
 	StateMutability m_currentBestMutability = StateMutability::Payable;
 	FunctionDefinition const* m_currentFunction = nullptr;
 	std::map<ModifierDefinition const*, StateMutability> m_inferredMutability;
diff --git a/test/libsolidity/ViewPureChecker.cpp b/test/libsolidity/ViewPureChecker.cpp
index 3f02564f..80241519 100644
--- a/test/libsolidity/ViewPureChecker.cpp
+++ b/test/libsolidity/ViewPureChecker.cpp
@@ -143,6 +143,16 @@ BOOST_AUTO_TEST_CASE(environment_access)
 	}
 }
 
+BOOST_AUTO_TEST_CASE(view_error_for_050)
+{
+	CHECK_ERROR(
+		"pragma experimental \"v0.5.0\"; contract C { uint x; function f() view { x = 2; } }",
+		TypeError,
+		"Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable."
+	);
+
+}
+
 BOOST_AUTO_TEST_CASE(modifiers)
 {
 	string text = R"(