Introduce the concept of builtin functions.

libyul/AsmAnalysis.cpp

@@ -101,7 +101,7 @@ bool AsmAnalyzer::operator()(Literal const& _literal)
 	}
 	else if (_literal.kind == LiteralKind::Boolean)
 	{
-		solAssert(m_flavour == AsmFlavour::Yul, "");
+		solAssert(m_dialect.flavour == AsmFlavour::Yul, "");
 		solAssert(_literal.value == YulString{string("true")} || _literal.value == YulString{string("false")}, "");
 	}
 	m_info.stackHeightInfo[&_literal] = m_stackHeight;
@@ -164,7 +164,7 @@ bool AsmAnalyzer::operator()(Identifier const& _identifier)
 
 bool AsmAnalyzer::operator()(FunctionalInstruction const& _instr)
 {
-	solAssert(m_flavour != AsmFlavour::Yul, "");
+	solAssert(m_dialect.flavour != AsmFlavour::Yul, "");
 	bool success = true;
 	for (auto const& arg: _instr.arguments | boost::adaptors::reversed)
 		if (!expectExpression(arg))
@@ -182,9 +182,9 @@ bool AsmAnalyzer::operator()(ExpressionStatement const& _statement)
 {
 	int initialStackHeight = m_stackHeight;
 	bool success = boost::apply_visitor(*this, _statement.expression);
-	if (m_stackHeight != initialStackHeight && (m_flavour != AsmFlavour::Loose || m_errorTypeForLoose))
+	if (m_stackHeight != initialStackHeight && (m_dialect.flavour != AsmFlavour::Loose || m_errorTypeForLoose))
 	{
-		Error::Type errorType = m_flavour == AsmFlavour::Loose ? *m_errorTypeForLoose : Error::Type::TypeError;
+		Error::Type errorType = m_dialect.flavour == AsmFlavour::Loose ? *m_errorTypeForLoose : Error::Type::TypeError;
 		string msg =
 			"Top-level expressions are not supposed to return values (this expression returns " +
 			to_string(m_stackHeight - initialStackHeight) +
@@ -563,7 +563,7 @@ Scope& AsmAnalyzer::scope(Block const* _block)
 }
 void AsmAnalyzer::expectValidType(string const& type, SourceLocation const& _location)
 {
-	if (m_flavour != AsmFlavour::Yul)
+	if (m_dialect.flavour != AsmFlavour::Yul)
 		return;
 
 	if (!builtinTypes.count(type))
@@ -623,7 +623,7 @@ void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocatio
 
 	if (_instr == solidity::Instruction::JUMP || _instr == solidity::Instruction::JUMPI || _instr == solidity::Instruction::JUMPDEST)
 	{
-		solAssert(m_flavour == AsmFlavour::Loose, "");
+		solAssert(m_dialect.flavour == AsmFlavour::Loose, "");
 		m_errorReporter.error(
 			m_errorTypeForLoose ? *m_errorTypeForLoose : Error::Type::Warning,
 			_location,
@@ -636,7 +636,7 @@ void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocatio
 
 void AsmAnalyzer::checkLooseFeature(SourceLocation const& _location, string const& _description)
 {
-	if (m_flavour != AsmFlavour::Loose)
+	if (m_dialect.flavour != AsmFlavour::Loose)
 		solAssert(false, _description);
 	else if (m_errorTypeForLoose)
 		m_errorReporter.error(*m_errorTypeForLoose, _location, _description);

libyul/AsmAnalysis.h

@@ -23,12 +23,12 @@
 #include <liblangutil/Exceptions.h>
 #include <liblangutil/EVMVersion.h>
 
+#include <libyul/Dialect.h>
 #include <libyul/AsmScope.h>
+#include <libyul/AsmDataForward.h>
 
 #include <libyul/backends/evm/AbstractAssembly.h>
 
-#include <libyul/AsmDataForward.h>
-
 #include <boost/variant.hpp>
 #include <boost/optional.hpp>
 
@@ -59,14 +59,14 @@ public:
 		langutil::ErrorReporter& _errorReporter,
 		dev::solidity::EVMVersion _evmVersion,
 		boost::optional<langutil::Error::Type> _errorTypeForLoose,
-		AsmFlavour _flavour = AsmFlavour::Loose,
+		Dialect _dialect = Dialect::looseAssemblyForEVM(),
 		ExternalIdentifierAccess::Resolver const& _resolver = ExternalIdentifierAccess::Resolver()
 	):
 		m_resolver(_resolver),
 		m_info(_analysisInfo),
 		m_errorReporter(_errorReporter),
 		m_evmVersion(_evmVersion),
-		m_flavour(_flavour),
+		m_dialect(std::move(_dialect)),
 		m_errorTypeForLoose(_errorTypeForLoose)
 	{}
 
@@ -115,7 +115,7 @@ private:
 	AsmAnalysisInfo& m_info;
 	langutil::ErrorReporter& m_errorReporter;
 	dev::solidity::EVMVersion m_evmVersion;
-	AsmFlavour m_flavour = AsmFlavour::Loose;
+	Dialect m_dialect = Dialect::looseAssemblyForEVM();
 	boost::optional<langutil::Error::Type> m_errorTypeForLoose;
 };
 

libyul/AsmDataForward.h

@@ -49,11 +49,4 @@ struct TypedName;
 using Expression = boost::variant<FunctionalInstruction, FunctionCall, Identifier, Literal>;
 using Statement = boost::variant<ExpressionStatement, Instruction, Label, StackAssignment, Assignment, VariableDeclaration, FunctionDefinition, If, Switch, ForLoop, Block>;
 
-enum class AsmFlavour
-{
-	Loose,  // no types, EVM instructions as function, jumps and direct stack manipulations
-	Strict, // no types, EVM instructions as functions, but no jumps and no direct stack manipulations
-	Yul     // same as Strict mode with types
-};
-
 }

libyul/AsmParser.cpp

@@ -107,7 +107,7 @@ Statement Parser::parseStatement()
 		return parseForLoop();
 	case Token::Assign:
 	{
-		if (m_flavour != AsmFlavour::Loose)
+		if (m_dialect.flavour != AsmFlavour::Loose)
 			break;
 		StackAssignment assignment = createWithLocation<StackAssignment>();
 		advance();
@@ -174,7 +174,7 @@ Statement Parser::parseStatement()
 		if (currentToken() == Token::Assign && peekNextToken() != Token::Colon)
 		{
 			Assignment assignment = createWithLocation<Assignment>(identifier.location);
-			if (m_flavour != AsmFlavour::Yul && instructions().count(identifier.name.str()))
+			if (m_dialect.flavour != AsmFlavour::Yul && instructions().count(identifier.name.str()))
 				fatalParserError("Cannot use instruction names for identifier names.");
 			advance();
 			assignment.variableNames.emplace_back(identifier);
@@ -185,7 +185,7 @@ Statement Parser::parseStatement()
 		else
 		{
 			// label
-			if (m_flavour != AsmFlavour::Loose)
+			if (m_dialect.flavour != AsmFlavour::Loose)
 				fatalParserError("Labels are not supported.");
 			Label label = createWithLocation<Label>(identifier.location);
 			label.name = identifier.name;
@@ -193,7 +193,7 @@ Statement Parser::parseStatement()
 		}
 	}
 	default:
-		if (m_flavour != AsmFlavour::Loose)
+		if (m_dialect.flavour != AsmFlavour::Loose)
 			fatalParserError("Call or assignment expected.");
 		break;
 	}
@@ -269,7 +269,7 @@ Expression Parser::parseExpression()
 				instructionNames().at(instr.instruction) +
 				"\" not allowed in this context."
 			);
-		if (m_flavour != AsmFlavour::Loose && currentToken() != Token::LParen)
+		if (m_dialect.flavour != AsmFlavour::Loose && currentToken() != Token::LParen)
 			fatalParserError(
 				"Non-functional instructions are not allowed in this context."
 			);
@@ -289,7 +289,7 @@ Expression Parser::parseExpression()
 	else if (operation.type() == typeid(Instruction))
 	{
 		// Instructions not taking arguments are allowed as expressions.
-		solAssert(m_flavour == AsmFlavour::Loose, "");
+		solAssert(m_dialect.flavour == AsmFlavour::Loose, "");
 		Instruction& instr = boost::get<Instruction>(operation);
 		return FunctionalInstruction{std::move(instr.location), instr.instruction, {}};
 	}
@@ -358,7 +358,7 @@ Parser::ElementaryOperation Parser::parseElementaryOperation()
 		else
 			literal = YulString{currentLiteral()};
 		// first search the set of instructions.
-		if (m_flavour != AsmFlavour::Yul && instructions().count(literal.str()))
+		if (m_dialect.flavour != AsmFlavour::Yul && instructions().count(literal.str()))
 		{
 			dev::solidity::Instruction const& instr = instructions().at(literal.str());
 			ret = Instruction{location(), instr};
@@ -399,7 +399,7 @@ Parser::ElementaryOperation Parser::parseElementaryOperation()
 			{}
 		};
 		advance();
-		if (m_flavour == AsmFlavour::Yul)
+		if (m_dialect.flavour == AsmFlavour::Yul)
 		{
 			expectToken(Token::Colon);
 			literal.location.end = endPosition();
@@ -412,7 +412,7 @@ Parser::ElementaryOperation Parser::parseElementaryOperation()
 	}
 	default:
 		fatalParserError(
-			m_flavour == AsmFlavour::Yul ?
+			m_dialect.flavour == AsmFlavour::Yul ?
 			"Literal or identifier expected." :
 			"Literal, identifier or instruction expected."
 		);
@@ -482,7 +482,7 @@ Expression Parser::parseCall(Parser::ElementaryOperation&& _initialOp)
 	RecursionGuard recursionGuard(*this);
 	if (_initialOp.type() == typeid(Instruction))
 	{
-		solAssert(m_flavour != AsmFlavour::Yul, "Instructions are invalid in Yul");
+		solAssert(m_dialect.flavour != AsmFlavour::Yul, "Instructions are invalid in Yul");
 		Instruction& instruction = boost::get<Instruction>(_initialOp);
 		FunctionalInstruction ret;
 		ret.instruction = instruction.instruction;
@@ -553,7 +553,7 @@ Expression Parser::parseCall(Parser::ElementaryOperation&& _initialOp)
 	}
 	else
 		fatalParserError(
-			m_flavour == AsmFlavour::Yul ?
+			m_dialect.flavour == AsmFlavour::Yul ?
 			"Function name expected." :
 			"Assembly instruction or function name required in front of \"(\")"
 		);
@@ -566,7 +566,7 @@ TypedName Parser::parseTypedName()
 	RecursionGuard recursionGuard(*this);
 	TypedName typedName = createWithLocation<TypedName>();
 	typedName.name = expectAsmIdentifier();
-	if (m_flavour == AsmFlavour::Yul)
+	if (m_dialect.flavour == AsmFlavour::Yul)
 	{
 		expectToken(Token::Colon);
 		typedName.location.end = endPosition();
@@ -578,7 +578,7 @@ TypedName Parser::parseTypedName()
 YulString Parser::expectAsmIdentifier()
 {
 	YulString name = YulString{currentLiteral()};
-	if (m_flavour == AsmFlavour::Yul)
+	if (m_dialect.flavour == AsmFlavour::Yul)
 	{
 		switch (currentToken())
 		{

libyul/AsmParser.h

@@ -22,21 +22,24 @@
 
 #pragma once
 
-#include <memory>
-#include <vector>
 #include <libyul/AsmData.h>
+#include <libyul/Dialect.h>
+
 #include <liblangutil/SourceLocation.h>
 #include <liblangutil/Scanner.h>
 #include <liblangutil/ParserBase.h>
 
+#include <memory>
+#include <vector>
+
 namespace yul
 {
 
 class Parser: public langutil::ParserBase
 {
 public:
-	explicit Parser(langutil::ErrorReporter& _errorReporter, AsmFlavour _flavour = AsmFlavour::Loose):
-		ParserBase(_errorReporter), m_flavour(_flavour) {}
+	explicit Parser(langutil::ErrorReporter& _errorReporter, Dialect _dialect = Dialect::looseAssemblyForEVM()):
+		ParserBase(_errorReporter), m_dialect(std::move(_dialect)) {}
 
 	/// Parses an inline assembly block starting with `{` and ending with `}`.
 	/// @param _reuseScanner if true, do check for end of input after the `}`.
@@ -83,7 +86,7 @@ protected:
 	static bool isValidNumberLiteral(std::string const& _literal);
 
 private:
-	AsmFlavour m_flavour = AsmFlavour::Loose;
+	Dialect m_dialect = Dialect::looseAssemblyForEVM();
 };
 
 }

libyul/Dialect.h

@@ -0,0 +1,82 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Yul dialect.
+ */
+
+#pragma once
+
+#include <libyul/YulString.h>
+
+#include <memory>
+
+namespace yul
+{
+
+class YulString;
+using Type = YulString;
+
+enum class AsmFlavour
+{
+	Loose,  // no types, EVM instructions as function, jumps and direct stack manipulations
+	Strict, // no types, EVM instructions as functions, but no jumps and no direct stack manipulations
+	Yul     // same as Strict mode with types
+};
+
+struct BuiltinFunction
+{
+	YulString name;
+	std::vector<Type> parameters;
+	std::vector<Type> returns;
+	bool movable;
+};
+
+/**
+ * Class to query for builtin functions and their semantics.
+ */
+struct Builtins
+{
+	virtual ~Builtins() = default;
+	/// @returns the builtin function of the given name or a nullptr if it is not a builtin function.
+	virtual BuiltinFunction const* query(YulString /*_name*/) const { return nullptr; }
+};
+
+struct Dialect
+{
+	AsmFlavour flavour = AsmFlavour::Loose;
+	std::shared_ptr<Builtins> builtins;
+
+	Dialect(AsmFlavour _flavour, std::shared_ptr<Builtins> _builtins):
+		flavour(_flavour), builtins(std::move(_builtins))
+	{}
+	static Dialect looseAssemblyForEVM()
+	{
+		return Dialect{AsmFlavour::Loose, std::make_shared<Builtins>()};
+	}
+	static Dialect strictAssemblyForEVM()
+	{
+		// The EVM instructions will be moved to builtins at some point.
+		return Dialect{AsmFlavour::Strict, std::make_shared<Builtins>()};
+	}
+	static Dialect yul()
+	{
+		// Will have to add builtins later.
+		return Dialect{AsmFlavour::Yul, std::make_shared<Builtins>()};
+	}
+};
+
+}

libyul/ObjectParser.cpp

@@ -104,7 +104,7 @@ shared_ptr<Block> ObjectParser::parseCode()
 
 shared_ptr<Block> ObjectParser::parseBlock()
 {
-	Parser parser(m_errorReporter, m_flavour);
+	Parser parser(m_errorReporter, m_dialect);
 	shared_ptr<Block> block = parser.parse(m_scanner, true);
 	yulAssert(block || m_errorReporter.hasErrors(), "Invalid block but no error!");
 	return block;

libyul/ObjectParser.h

@@ -22,6 +22,7 @@
 
 #include <libyul/YulString.h>
 #include <libyul/Object.h>
+#include <libyul/Dialect.h>
 
 #include <liblangutil/ErrorReporter.h>
 #include <liblangutil/ParserBase.h>
@@ -46,9 +47,9 @@ class ObjectParser: public langutil::ParserBase
 public:
 	explicit ObjectParser(
 		langutil::ErrorReporter& _errorReporter,
-		yul::AsmFlavour _flavour = yul::AsmFlavour::Loose
+		Dialect _dialect = Dialect::looseAssemblyForEVM()
 	):
-		ParserBase(_errorReporter), m_flavour(_flavour) {}
+		ParserBase(_errorReporter), m_dialect(std::move(_dialect)) {}
 
 	/// Parses a Yul object.
 	/// Falls back to code-only parsing if the source starts with `{`.
@@ -66,7 +67,7 @@ private:
 	YulString parseUniqueName(Object const* _containingObject);
 	void addNamedSubObject(Object& _container, YulString _name, std::shared_ptr<ObjectNode> _subObject);
 
-	yul::AsmFlavour m_flavour;
+	Dialect m_dialect;
 };
 
 }