5 files changed, 47 insertions, 1 deletions

diff --git a/libsolidity/analysis/NameAndTypeResolver.cpp b/libsolidity/analysis/NameAndTypeResolver.cpp
index 2742dcf2..aac90311 100644
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@@ -26,6 +26,8 @@
 #include <libsolidity/analysis/TypeChecker.h>
 #include <libsolidity/interface/ErrorReporter.h>
 
+#include <boost/algorithm/string.hpp>
+
 using namespace std;
 
 namespace dev
@@ -232,6 +234,26 @@ vector<Declaration const*> NameAndTypeResolver::cleanedDeclarations(
 	return uniqueFunctions;
 }
 
+void NameAndTypeResolver::warnVariablesNamedLikeInstructions()
+{
+	for (auto const& instruction: c_instructions)
+	{
+		string const instructionName{boost::algorithm::to_lower_copy(instruction.first)};
+		auto declarations = nameFromCurrentScope(instructionName);
+		for (Declaration const* const declaration: declarations)
+		{
+			solAssert(!!declaration, "");
+			if (dynamic_cast<MagicVariableDeclaration const* const>(declaration))
+				// Don't warn the user for what the user did not.
+				continue;
+			m_errorReporter.warning(
+				declaration->location(),
+				"Variable is shadowed in inline assembly by an instruction of the same name"
+			);
+		}
+	}
+}
+
 bool NameAndTypeResolver::resolveNamesAndTypesInternal(ASTNode& _node, bool _resolveInsideCode)
 {
 	if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(&_node))
diff --git a/libsolidity/analysis/NameAndTypeResolver.h b/libsolidity/analysis/NameAndTypeResolver.h
index 0441867d..84628778 100644
--- a/libsolidity/analysis/NameAndTypeResolver.h
+++ b/libsolidity/analysis/NameAndTypeResolver.h
@@ -90,6 +90,9 @@ public:
 		std::vector<Declaration const*> const& _declarations
 	);
 
+	/// Generate and store warnings about variables that are named like instructions.
+	void warnVariablesNamedLikeInstructions();
+
 private:
 	/// Internal version of @a resolveNamesAndTypes (called from there) throws exceptions on fatal errors.
 	bool resolveNamesAndTypesInternal(ASTNode& _node, bool _resolveInsideCode = true);
diff --git a/libsolidity/analysis/ReferencesResolver.cpp b/libsolidity/analysis/ReferencesResolver.cpp
index edf2fc02..2a5f27df 100644
--- a/libsolidity/analysis/ReferencesResolver.cpp
+++ b/libsolidity/analysis/ReferencesResolver.cpp
@@ -162,6 +162,8 @@ void ReferencesResolver::endVisit(ArrayTypeName const& _typeName)
 
 bool ReferencesResolver::visit(InlineAssembly const& _inlineAssembly)
 {
+	m_resolver.warnVariablesNamedLikeInstructions();
+
 	// Errors created in this stage are completely ignored because we do not yet know
 	// the type and size of external identifiers, which would result in false errors.
 	// The only purpose of this step is to fill the inline assembly annotation with
diff --git a/libsolidity/inlineasm/AsmAnalysis.cpp b/libsolidity/inlineasm/AsmAnalysis.cpp
index 13852880..36ac0e75 100644
--- a/libsolidity/inlineasm/AsmAnalysis.cpp
+++ b/libsolidity/inlineasm/AsmAnalysis.cpp
@@ -65,6 +65,7 @@ bool AsmAnalyzer::operator()(assembly::Instruction const& _instruction)
 	auto const& info = instructionInfo(_instruction.instruction);
 	m_stackHeight += info.ret - info.args;
 	m_info.stackHeightInfo[&_instruction] = m_stackHeight;
+	warnOnFutureInstruction(_instruction.instruction, _instruction.location);
 	return true;
 }
 
@@ -149,6 +150,7 @@ bool AsmAnalyzer::operator()(FunctionalInstruction const& _instr)
 	if (!(*this)(_instr.instruction))
 		success = false;
 	m_info.stackHeightInfo[&_instr] = m_stackHeight;
+	warnOnFutureInstruction(_instr.instruction.instruction, _instr.location);
 	return success;
 }
 
@@ -431,7 +433,6 @@ Scope& AsmAnalyzer::scope(Block const* _block)
 	solAssert(scopePtr, "Scope requested but not present.");
 	return *scopePtr;
 }
-
 void AsmAnalyzer::expectValidType(string const& type, SourceLocation const& _location)
 {
 	if (!m_julia)
@@ -443,3 +444,20 @@ void AsmAnalyzer::expectValidType(string const& type, SourceLocation const& _loc
 			"\"" + type + "\" is not a valid type (user defined types are not yet supported)."
 		);
 }
+
+void AsmAnalyzer::warnOnFutureInstruction(solidity::Instruction _instr, SourceLocation const& _location)
+{
+	switch (_instr)
+	{
+	case solidity::Instruction::RETURNDATASIZE:
+	case solidity::Instruction::RETURNDATACOPY:
+		m_errorReporter.warning(
+			_location,
+			"The RETURNDATASIZE/RETURNDATACOPY instructions are only available after "
+			"the Metropolis hard fork. Before that they act as an invalid instruction."
+		);
+		break;
+	default:
+		break;
+	}
+}
diff --git a/libsolidity/inlineasm/AsmAnalysis.h b/libsolidity/inlineasm/AsmAnalysis.h
index e7748bcf..55b409ba 100644
--- a/libsolidity/inlineasm/AsmAnalysis.h
+++ b/libsolidity/inlineasm/AsmAnalysis.h
@@ -97,6 +97,7 @@ private:
 
 	Scope& scope(assembly::Block const* _block);
 	void expectValidType(std::string const& type, SourceLocation const& _location);
+	void warnOnFutureInstruction(solidity::Instruction _instr, SourceLocation const& _location);
 
 	int m_stackHeight = 0;
 	julia::ExternalIdentifierAccess::Resolver m_resolver;