Merge pull request #3652 from ethereum/gasleft_v2

Use StaticAnalyzer to deprecate msg.gas instead of conditionally remo…

4 files changed, 24 insertions, 18 deletions

diff --git a/libsolidity/analysis/StaticAnalyzer.cpp b/libsolidity/analysis/StaticAnalyzer.cpp
index bd8ee597..d4de219a 100644
--- a/libsolidity/analysis/StaticAnalyzer.cpp
+++ b/libsolidity/analysis/StaticAnalyzer.cpp
@@ -139,6 +139,23 @@ bool StaticAnalyzer::visit(ExpressionStatement const& _statement)
 
 bool StaticAnalyzer::visit(MemberAccess const& _memberAccess)
 {
+	bool const v050 = m_currentContract->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050);
+
+	if (MagicType const* type = dynamic_cast<MagicType const*>(_memberAccess.expression().annotation().type.get()))
+		if (type->kind() == MagicType::Kind::Message && _memberAccess.memberName() == "gas")
+		{
+			if (v050)
+				m_errorReporter.typeError(
+					_memberAccess.location(),
+					"\"msg.gas\" has been deprecated in favor of \"gasleft()\""
+				);
+			else
+				m_errorReporter.warning(
+					_memberAccess.location(),
+					"\"msg.gas\" has been deprecated in favor of \"gasleft()\""
+				);
+		}
+
 	if (m_nonPayablePublic && !m_library)
 		if (MagicType const* type = dynamic_cast<MagicType const*>(_memberAccess.expression().annotation().type.get()))
 			if (type->kind() == MagicType::Kind::Message && _memberAccess.memberName() == "value")
@@ -151,7 +168,7 @@ bool StaticAnalyzer::visit(MemberAccess const& _memberAccess)
 		if (auto const* type = dynamic_cast<FunctionType const*>(_memberAccess.annotation().type.get()))
 			if (type->kind() == FunctionType::Kind::BareCallCode)
 			{
-				if (m_currentContract->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050))
+				if (v050)
 					m_errorReporter.typeError(
 						_memberAccess.location(),
 						"\"callcode\" has been deprecated in favour of \"delegatecall\"."
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 26bde1c4..771ae643 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -3000,10 +3000,8 @@ bool MagicType::operator==(Type const& _other) const
 	return other.m_kind == m_kind;
 }
 
-MemberList::MemberMap MagicType::nativeMembers(ContractDefinition const* _contract) const
+MemberList::MemberMap MagicType::nativeMembers(ContractDefinition const*) const
 {
-	solAssert(_contract, "");
-	const bool v050 = _contract->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050);
 	switch (m_kind)
 	{
 	case Kind::Block:
@@ -3016,17 +3014,13 @@ MemberList::MemberMap MagicType::nativeMembers(ContractDefinition const* _contra
 			{"gaslimit", make_shared<IntegerType>(256)}
 		});
 	case Kind::Message:
-	{
-		std::vector<MemberList::Member> members = {
+		return MemberList::MemberMap({
 			{"sender", make_shared<IntegerType>(160, IntegerType::Modifier::Address)},
+			{"gas", make_shared<IntegerType>(256)},
 			{"value", make_shared<IntegerType>(256)},
 			{"data", make_shared<ArrayType>(DataLocation::CallData)},
 			{"sig", make_shared<FixedBytesType>(4)}
-		};
-		if (!v050)
-			members.emplace_back("gas", make_shared<IntegerType>(256));
-		return members;
-	}
+		});
 	case Kind::Transaction:
 		return MemberList::MemberMap({
 			{"origin", make_shared<IntegerType>(160, IntegerType::Modifier::Address)},
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 0ce70f38..d27af7db 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -924,8 +924,6 @@ bool ExpressionCompiler::visit(NewExpression const&)
 
 bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 {
-	bool const v050 = m_context.experimentalFeatureActive(ExperimentalFeature::V050);
-
 	CompilerContext::LocationSetter locationSetter(m_context, _memberAccess);
 	// Check whether the member is a bound function.
 	ASTString const& member = _memberAccess.memberName();
@@ -1141,10 +1139,7 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 		else if (member == "origin")
 			m_context << Instruction::ORIGIN;
 		else if (member == "gas")
-		{
-			solAssert(!v050, "");
 			m_context << Instruction::GAS;
-		}
 		else if (member == "gasprice")
 			m_context << Instruction::GASPRICE;
 		else if (member == "data")
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 7b0a7d4c..b6e2cd43 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -7417,7 +7417,7 @@ BOOST_AUTO_TEST_CASE(gasleft)
 			function f() public view returns (uint256 val) { return msg.gas; }
 		}
 	)";
-	CHECK_SUCCESS_NO_WARNINGS(text);
+	CHECK_WARNING(text, "\"msg.gas\" has been deprecated in favor of \"gasleft()\"");
 
 	text = R"(
 		contract C {
@@ -7432,7 +7432,7 @@ BOOST_AUTO_TEST_CASE(gasleft)
 			function f() public returns (uint256 val) { return msg.gas; }
 		}
 	)";
-	CHECK_ERROR(text, TypeError, "Member \"gas\" not found or not visible after argument-dependent lookup in msg");
+	CHECK_ERROR(text, TypeError, "\"msg.gas\" has been deprecated in favor of \"gasleft()\"");
 }
 
 BOOST_AUTO_TEST_CASE(gasleft_shadowing)