Allow memory-safe inline assembly dialect flag.

Author: ekpyron

libsolidity/analysis/DocStringTagParser.cpp

@@ -202,7 +202,17 @@ bool DocStringTagParser::visit(InlineAssembly const& _assembly)
 				if (valuesSeen.insert(value).second)
 				{
 					if (value == "memory-safe-assembly")
+					{
+						if (_assembly.annotation().markedMemorySafe)
+							m_errorReporter.warning(
+								8544_error,
+								_assembly.location(),
+								"Inline assembly marked as memory safe using both a NatSpec tag and an assembly flag. "
+								"If you are not concerned with backwards compatibility, only use the assembly flag, "
+								"otherwise only use the NatSpec tag."
+							);
 						_assembly.annotation().markedMemorySafe = true;
+					}
 					else
 						m_errorReporter.warning(
 							8787_error,

libsolidity/analysis/SyntaxChecker.cpp

@@ -334,6 +334,27 @@ bool SyntaxChecker::visit(UnaryOperation const& _operation)
 
 bool SyntaxChecker::visit(InlineAssembly const& _inlineAssembly)
 {
+	if (_inlineAssembly.flags())
+		for (auto flag: *_inlineAssembly.flags())
+		{
+			if (*flag == "memory-safe")
+			{
+				if (_inlineAssembly.annotation().markedMemorySafe)
+					m_errorReporter.syntaxError(
+						7026_error,
+						_inlineAssembly.location(),
+						"Inline assembly marked memory-safe multiple times."
+					);
+				_inlineAssembly.annotation().markedMemorySafe = true;
+			}
+			else
+				m_errorReporter.warning(
+					4430_error,
+					_inlineAssembly.location(),
+					"Unknown inline assembly flag: \"" + *flag + "\""
+				);
+		}
+
 	if (!m_useYulOptimizer)
 		return false;
 

libsolidity/ast/AST.h

@@ -1463,19 +1463,26 @@ class InlineAssembly: public Statement
 		SourceLocation const& _location,
 		ASTPointer<ASTString> const& _docString,
 		yul::Dialect const& _dialect,
+		ASTPointer<std::vector<ASTPointer<ASTString>>> _flags,
 		std::shared_ptr<yul::Block> _operations
 	):
-		Statement(_id, _location, _docString), m_dialect(_dialect), m_operations(std::move(_operations)) {}
+		Statement(_id, _location, _docString),
+		m_dialect(_dialect),
+		m_flags(move(_flags)),
+		m_operations(std::move(_operations))
+	{}
 	void accept(ASTVisitor& _visitor) override;
 	void accept(ASTConstVisitor& _visitor) const override;
 
 	yul::Dialect const& dialect() const { return m_dialect; }
 	yul::Block const& operations() const { return *m_operations; }
+	ASTPointer<std::vector<ASTPointer<ASTString>>> const& flags() const { return m_flags; }
 
 	InlineAssemblyAnnotation& annotation() const override;
 
 private:
 	yul::Dialect const& m_dialect;
+	ASTPointer<std::vector<ASTPointer<ASTString>>> m_flags;
 	std::shared_ptr<yul::Block> m_operations;
 };
 

libsolidity/ast/ASTJsonConverter.cpp

@@ -600,11 +600,23 @@ bool ASTJsonConverter::visit(InlineAssembly const& _node)
 	for (Json::Value& it: externalReferences | ranges::views::values)
 		externalReferencesJson.append(std::move(it));
 
-	setJsonNode(_node, "InlineAssembly", {
+	std::vector<pair<string, Json::Value>> attributes = {
 		make_pair("AST", Json::Value(yul::AsmJsonConverter(sourceIndexFromLocation(_node.location()))(_node.operations()))),
 		make_pair("externalReferences", std::move(externalReferencesJson)),
 		make_pair("evmVersion", dynamic_cast<solidity::yul::EVMDialect const&>(_node.dialect()).evmVersion().name())
-	});
+	};
+
+	if (_node.flags())
+	{
+		Json::Value flags(Json::arrayValue);
+		for (auto const& flag: *_node.flags())
+			if (flag)
+				flags.append(*flag);
+			else
+				flags.append(Json::nullValue);
+		attributes.emplace_back(make_pair("flags", move(flags)));
+	}
+	setJsonNode(_node, "InlineAssembly", move(attributes));
 
 	return false;
 }

libsolidity/ast/ASTJsonImporter.cpp

@@ -626,11 +626,24 @@ ASTPointer<InlineAssembly> ASTJsonImporter::createInlineAssembly(Json::Value con
 	astAssert(m_evmVersion == evmVersion, "Imported tree evm version differs from configured evm version!");
 
 	yul::Dialect const& dialect = yul::EVMDialect::strictAssemblyForEVM(evmVersion.value());
+	ASTPointer<vector<ASTPointer<ASTString>>> flags;
+	if (_node.isMember("flags"))
+	{
+		flags = make_shared<vector<ASTPointer<ASTString>>>();
+		Json::Value const& flagsNode = _node["flags"];
+		astAssert(flagsNode.isArray(), "Assembly flags must be an array.");
+		for (Json::ArrayIndex i = 0; i < flagsNode.size(); ++i)
+		{
+			astAssert(flagsNode[i].isString(), "Assembly flag must be a string.");
+			flags->emplace_back(make_shared<ASTString>(flagsNode[i].asString()));
+		}
+	}
 	shared_ptr<yul::Block> operations = make_shared<yul::Block>(yul::AsmJsonImporter(m_sourceNames).createBlock(member(_node, "AST")));
 	return createASTNode<InlineAssembly>(
 		_node,
 		nullOrASTString(_node, "documentation"),
 		dialect,
+		move(flags),
 		operations
 	);
 }

libsolidity/parsing/Parser.cpp

@@ -1321,13 +1321,28 @@ ASTPointer<InlineAssembly> Parser::parseInlineAssembly(ASTPointer<ASTString> con
 		advance();
 	}
 
+	ASTPointer<vector<ASTPointer<ASTString>>> flags;
+	if (m_scanner->currentToken() == Token::LParen)
+	{
+		flags = make_shared<vector<ASTPointer<ASTString>>>();
+		do
+		{
+			advance();
+			expectToken(Token::StringLiteral, false);
+			flags->emplace_back(make_shared<ASTString>(m_scanner->currentLiteral()));
+			advance();
+		}
+		while (m_scanner->currentToken() == Token::Comma);
+		expectToken(Token::RParen);
+	}
+
 	yul::Parser asmParser(m_errorReporter, dialect);
 	shared_ptr<yul::Block> block = asmParser.parseInline(m_scanner);
 	if (block == nullptr)
 		BOOST_THROW_EXCEPTION(FatalError());
 
 	location.end = nativeLocationOf(*block).end;
-	return make_shared<InlineAssembly>(nextID(), location, _docString, dialect, block);
+	return make_shared<InlineAssembly>(nextID(), location, _docString, dialect, move(flags), block);
 }
 
 ASTPointer<IfStatement> Parser::parseIfStatement(ASTPointer<ASTString> const& _docString)