From 3da2b67b674f20a59a22e80e399c7d215011b50c Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Thu, 30 Jul 2020 12:12:55 +0100
Subject: [PATCH 1/9] simplify parser

---
 libyul/AsmParser.cpp                          | 33 +++++++------------
 .../invalid/bare_instructions_disallowed.sol  |  2 +-
 .../invalid/unbalanced_negative_stack.sol     |  2 +-
 3 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index 00cdb4a22..19d0ced20 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -265,10 +265,12 @@ Expression Parser::parseExpression()
 	RecursionGuard recursionGuard(*this);
 
 	ElementaryOperation operation = parseElementaryOperation();
-	if (holds_alternative<FunctionCall>(operation) || currentToken() == Token::LParen)
-		return parseCall(std::move(operation));
-	else if (holds_alternative<Identifier>(operation))
+	if (holds_alternative<Identifier>(operation))
+	{
+		if (currentToken() == Token::LParen)
+			return parseCall(std::move(operation));
 		return std::get<Identifier>(operation);
+	}
 	else
 	{
 		yulAssert(holds_alternative<Literal>(operation), "");
@@ -284,16 +286,7 @@ Parser::ElementaryOperation Parser::parseElementaryOperation()
 	{
 	case Token::Identifier:
 	{
-		YulString literal{currentLiteral()};
-		if (m_dialect.builtin(literal))
-		{
-			Identifier identifier{currentLocation(), literal};
-			advance();
-			expectToken(Token::LParen, false);
-			return FunctionCall{identifier.location, identifier, {}};
-		}
-		else
-			ret = Identifier{currentLocation(), literal};
+		ret = Identifier{currentLocation(), YulString{currentLiteral()}};
 		advance();
 		break;
 	}
@@ -422,17 +415,13 @@ Expression Parser::parseCall(Parser::ElementaryOperation&& _initialOp)
 {
 	RecursionGuard recursionGuard(*this);
 
-	FunctionCall ret;
-	if (holds_alternative<Identifier>(_initialOp))
-	{
-		ret.functionName = std::move(std::get<Identifier>(_initialOp));
-		ret.location = ret.functionName.location;
-	}
-	else if (holds_alternative<FunctionCall>(_initialOp))
-		ret = std::move(std::get<FunctionCall>(_initialOp));
-	else
+	if (!holds_alternative<Identifier>(_initialOp))
 		fatalParserError(9980_error, "Function name expected.");
 
+	FunctionCall ret;
+	ret.functionName = std::move(std::get<Identifier>(_initialOp));
+	ret.location = ret.functionName.location;
+
 	expectToken(Token::LParen);
 	if (currentToken() != Token::RParen)
 	{
diff --git a/test/libsolidity/syntaxTests/inlineAssembly/invalid/bare_instructions_disallowed.sol b/test/libsolidity/syntaxTests/inlineAssembly/invalid/bare_instructions_disallowed.sol
index a55586af9..87884efee 100644
--- a/test/libsolidity/syntaxTests/inlineAssembly/invalid/bare_instructions_disallowed.sol
+++ b/test/libsolidity/syntaxTests/inlineAssembly/invalid/bare_instructions_disallowed.sol
@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// ParserError 2314: (95-98): Expected '(' but got identifier
+// ParserError 6913: (95-98): Call or assignment expected.
diff --git a/test/libsolidity/syntaxTests/inlineAssembly/invalid/unbalanced_negative_stack.sol b/test/libsolidity/syntaxTests/inlineAssembly/invalid/unbalanced_negative_stack.sol
index 3f92beec2..80dd3a587 100644
--- a/test/libsolidity/syntaxTests/inlineAssembly/invalid/unbalanced_negative_stack.sol
+++ b/test/libsolidity/syntaxTests/inlineAssembly/invalid/unbalanced_negative_stack.sol
@@ -6,4 +6,4 @@ contract test {
     }
 }
 // ----
-// ParserError 2314: (85-86): Expected '(' but got '}'
+// ParserError 6913: (85-86): Call or assignment expected.

From 75e00573884677b6854a6aea1e4c006978f54f1e Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Thu, 30 Jul 2020 12:20:15 +0100
Subject: [PATCH 2/9] Rename parseElementaryOperation to
 parseLiteralOrIdentifier

---
 libyul/AsmParser.cpp | 16 ++++++++--------
 libyul/AsmParser.h   |  2 +-
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index 19d0ced20..94dff259d 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -138,11 +138,11 @@ Statement Parser::parseStatement()
 	default:
 		break;
 	}
+
 	// Options left:
-	// Simple instruction (might turn into functional),
-	// literal,
-	// identifier (might turn into label or functional assignment)
-	ElementaryOperation elementary(parseElementaryOperation());
+	// Expression/FunctionCall
+	// Assignment
+	ElementaryOperation elementary(parseLiteralOrIdentifier());
 
 	switch (currentToken())
 	{
@@ -184,7 +184,7 @@ Statement Parser::parseStatement()
 
 			expectToken(Token::Comma);
 
-			elementary = parseElementaryOperation();
+			elementary = parseLiteralOrIdentifier();
 		}
 
 		expectToken(Token::AssemblyAssign);
@@ -225,7 +225,7 @@ Case Parser::parseCase()
 	else if (currentToken() == Token::Case)
 	{
 		advance();
-		ElementaryOperation literal = parseElementaryOperation();
+		ElementaryOperation literal = parseLiteralOrIdentifier();
 		if (!holds_alternative<Literal>(literal))
 			fatalParserError(4805_error, "Literal expected.");
 		_case.value = make_unique<Literal>(std::get<Literal>(std::move(literal)));
@@ -264,7 +264,7 @@ Expression Parser::parseExpression()
 {
 	RecursionGuard recursionGuard(*this);
 
-	ElementaryOperation operation = parseElementaryOperation();
+	ElementaryOperation operation = parseLiteralOrIdentifier();
 	if (holds_alternative<Identifier>(operation))
 	{
 		if (currentToken() == Token::LParen)
@@ -278,7 +278,7 @@ Expression Parser::parseExpression()
 	}
 }
 
-Parser::ElementaryOperation Parser::parseElementaryOperation()
+Parser::ElementaryOperation Parser::parseLiteralOrIdentifier()
 {
 	RecursionGuard recursionGuard(*this);
 	ElementaryOperation ret;
diff --git a/libyul/AsmParser.h b/libyul/AsmParser.h
index 705711b52..2720e9760 100644
--- a/libyul/AsmParser.h
+++ b/libyul/AsmParser.h
@@ -84,7 +84,7 @@ protected:
 	Expression parseExpression();
 	/// Parses an elementary operation, i.e. a literal, identifier, instruction or
 	/// builtin functian call (only the name).
-	ElementaryOperation parseElementaryOperation();
+	ElementaryOperation parseLiteralOrIdentifier();
 	VariableDeclaration parseVariableDeclaration();
 	FunctionDefinition parseFunctionDefinition();
 	Expression parseCall(ElementaryOperation&& _initialOp);

From baa7251f1d2600b7fe1c94026342b0a283368145 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Mon, 31 Aug 2020 15:29:12 +0100
Subject: [PATCH 3/9] More clean up

---
 libyul/AsmParser.cpp | 12 ++++++------
 libyul/AsmParser.h   |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index 94dff259d..58babaaac 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -149,7 +149,7 @@ Statement Parser::parseStatement()
 	case Token::LParen:
 	{
 		Expression expr = parseCall(std::move(elementary));
-		return ExpressionStatement{locationOf(expr), expr};
+		return ExpressionStatement{locationOf(expr), move(expr)};
 	}
 	case Token::Comma:
 	case Token::AssemblyAssign:
@@ -192,7 +192,7 @@ Statement Parser::parseStatement()
 		assignment.value = make_unique<Expression>(parseExpression());
 		assignment.location.end = locationOf(*assignment.value).end;
 
-		return Statement{std::move(assignment)};
+		return Statement{move(assignment)};
 	}
 	default:
 		fatalParserError(6913_error, "Call or assignment expected.");
@@ -201,13 +201,13 @@ Statement Parser::parseStatement()
 
 	if (holds_alternative<Identifier>(elementary))
 	{
-		Identifier& identifier = std::get<Identifier>(elementary);
+		Identifier identifier = std::get<Identifier>(move(elementary));
 		return ExpressionStatement{identifier.location, { move(identifier) }};
 	}
 	else if (holds_alternative<Literal>(elementary))
 	{
-		Expression expr = std::get<Literal>(elementary);
-		return ExpressionStatement{locationOf(expr), expr};
+		Literal literal = std::get<Literal>(move(elementary));
+		return ExpressionStatement{literal.location, { move(literal) }};
 	}
 	else
 	{
@@ -411,7 +411,7 @@ FunctionDefinition Parser::parseFunctionDefinition()
 	return funDef;
 }
 
-Expression Parser::parseCall(Parser::ElementaryOperation&& _initialOp)
+FunctionCall Parser::parseCall(Parser::ElementaryOperation&& _initialOp)
 {
 	RecursionGuard recursionGuard(*this);
 
diff --git a/libyul/AsmParser.h b/libyul/AsmParser.h
index 2720e9760..2dcbcd191 100644
--- a/libyul/AsmParser.h
+++ b/libyul/AsmParser.h
@@ -87,7 +87,7 @@ protected:
 	ElementaryOperation parseLiteralOrIdentifier();
 	VariableDeclaration parseVariableDeclaration();
 	FunctionDefinition parseFunctionDefinition();
-	Expression parseCall(ElementaryOperation&& _initialOp);
+	FunctionCall parseCall(ElementaryOperation&& _initialOp);
 	TypedName parseTypedName();
 	YulString expectAsmIdentifier();
 

From 43353bb6cae0e8915160a478bf993f5e028cb355 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Wed, 4 Nov 2020 16:55:03 +0000
Subject: [PATCH 4/9] update tests

---
 scripts/error_codes.py                                         | 2 +-
 .../syntaxTests/inlineAssembly/assignment_from_opcode_like.sol | 2 +-
 .../syntaxTests/inlineAssembly/assignment_to_opcode_like.sol   | 2 +-
 test/libyul/yulSyntaxTests/builtin_identifier_3.yul            | 2 +-
 test/libyul/yulSyntaxTests/builtin_identifier_6.yul            | 3 +--
 test/libyul/yulSyntaxTests/builtin_identifier_7.yul            | 3 +--
 test/libyul/yulSyntaxTests/for_expr_invalid_5.yul              | 3 ++-
 test/libyul/yulSyntaxTests/functional_partial.yul              | 2 +-
 test/libyul/yulSyntaxTests/if_statement_invalid_1.yul          | 3 ++-
 test/libyul/yulSyntaxTests/if_statement_invalid_4.yul          | 3 ++-
 test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul           | 2 +-
 11 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/scripts/error_codes.py b/scripts/error_codes.py
index 23c1657a7..9b106d0c0 100755
--- a/scripts/error_codes.py
+++ b/scripts/error_codes.py
@@ -223,7 +223,7 @@ def examine_id_coverage(top_dir, source_id_to_file_names, new_ids_only=False):
         "1123", "1220", "1584", "1823",
         "1988", "2657", "2800", "3356",
         "3893", "3996", "4010", "4802",
-        "5073", "5272", "5622", "6272", "7128",
+        "5073", "5272", "5622", "7128",
         "7589", "7593", "7653", "8065", "8084", "8140",
         "8312", "8592", "9085", "9390"
     }
diff --git a/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol b/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
index 3296252ea..e9d6f1983 100644
--- a/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
+++ b/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// ParserError 2314: (118-119): Expected '(' but got '}'
+// Warning 8261: (52-62): Variable is shadowed in inline assembly by an instruction of the same name
diff --git a/test/libsolidity/syntaxTests/inlineAssembly/assignment_to_opcode_like.sol b/test/libsolidity/syntaxTests/inlineAssembly/assignment_to_opcode_like.sol
index 7a783b9fe..51028e50c 100644
--- a/test/libsolidity/syntaxTests/inlineAssembly/assignment_to_opcode_like.sol
+++ b/test/libsolidity/syntaxTests/inlineAssembly/assignment_to_opcode_like.sol
@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// ParserError 2314: (101-103): Expected '(' but got ':='
+// ParserError 6272: (101-103): Cannot assign to builtin function "mload".
diff --git a/test/libyul/yulSyntaxTests/builtin_identifier_3.yul b/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
index 283d64b49..ece40e793 100644
--- a/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
+++ b/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
@@ -2,4 +2,4 @@
 	function f(x) { f(add) }
 }
 // ----
-// ParserError 2314: (24-25): Expected '(' but got ')'
+// DeclarationError 8198: (21-24): Identifier not found.
diff --git a/test/libyul/yulSyntaxTests/builtin_identifier_6.yul b/test/libyul/yulSyntaxTests/builtin_identifier_6.yul
index 8f3395d79..e261354fc 100644
--- a/test/libyul/yulSyntaxTests/builtin_identifier_6.yul
+++ b/test/libyul/yulSyntaxTests/builtin_identifier_6.yul
@@ -1,6 +1,5 @@
 {
-	// Test for the unreachable 6272_error
 	add := 1
 }
 // ----
-// ParserError 2314: (47-49): Expected '(' but got ':='
+// ParserError 6272: (7-9): Cannot assign to builtin function "add".
diff --git a/test/libyul/yulSyntaxTests/builtin_identifier_7.yul b/test/libyul/yulSyntaxTests/builtin_identifier_7.yul
index 391b190d9..c34da0363 100644
--- a/test/libyul/yulSyntaxTests/builtin_identifier_7.yul
+++ b/test/libyul/yulSyntaxTests/builtin_identifier_7.yul
@@ -1,7 +1,6 @@
 {
-	// Test for the unreachable 6272_error
 	function f() -> a, b {}
 	add, mul := f()
 }
 // ----
-// ParserError 2314: (71-72): Expected '(' but got ','
+// ParserError 6272: (31-32): Cannot assign to builtin function "add".
diff --git a/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul b/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
index acf9be847..7f89fb3f4 100644
--- a/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
+++ b/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
@@ -2,4 +2,5 @@
 	for {} mload {} {}
 }
 // ----
-// ParserError 2314: (16-17): Expected '(' but got '{'
+// DeclarationError 8198: (10-15): Identifier not found.
+// TypeError 1733: (10-15): Expected a value of boolean type "bool" but got "u256"
diff --git a/test/libyul/yulSyntaxTests/functional_partial.yul b/test/libyul/yulSyntaxTests/functional_partial.yul
index f66225658..5f65cb13f 100644
--- a/test/libyul/yulSyntaxTests/functional_partial.yul
+++ b/test/libyul/yulSyntaxTests/functional_partial.yul
@@ -2,4 +2,4 @@
     let x := byte
 }
 // ----
-// ParserError 2314: (20-21): Expected '(' but got '}'
+// DeclarationError 8198: (15-19): Identifier not found.
diff --git a/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul b/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
index 5f73fcf2a..8d40479cd 100644
--- a/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
+++ b/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
@@ -2,4 +2,5 @@
     if mload {}
 }
 // ----
-// ParserError 2314: (15-16): Expected '(' but got '{'
+// DeclarationError 8198: (9-14): Identifier not found.
+// TypeError 1733: (9-14): Expected a value of boolean type "bool" but got "u256"
diff --git a/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul b/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
index ed9deeda6..546537203 100644
--- a/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
+++ b/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
@@ -2,4 +2,5 @@
     if calldatasize {}
 }
 // ----
-// ParserError 2314: (22-23): Expected '(' but got '{'
+// DeclarationError 8198: (9-21): Identifier not found.
+// TypeError 1733: (9-21): Expected a value of boolean type "bool" but got "u256"
diff --git a/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul b/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
index 842fa02f3..905b9ed1f 100644
--- a/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
+++ b/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
@@ -4,4 +4,4 @@
     default {}
 }
 // ----
-// ParserError 2314: (23-27): Expected '(' but got reserved keyword 'case'
+// DeclarationError 8198: (13-18): Identifier not found.

From e2a756a705789e7601cc57ddd45c6f4e9ff727c6 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Thu, 5 Nov 2020 01:25:53 +0000
Subject: [PATCH 5/9] Remove dead code

---
 libyul/AsmParser.cpp | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index 58babaaac..e19f5b8ce 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -199,21 +199,8 @@ Statement Parser::parseStatement()
 		break;
 	}
 
-	if (holds_alternative<Identifier>(elementary))
-	{
-		Identifier identifier = std::get<Identifier>(move(elementary));
-		return ExpressionStatement{identifier.location, { move(identifier) }};
-	}
-	else if (holds_alternative<Literal>(elementary))
-	{
-		Literal literal = std::get<Literal>(move(elementary));
-		return ExpressionStatement{literal.location, { move(literal) }};
-	}
-	else
-	{
-		yulAssert(false, "Invalid elementary operation.");
-		return {};
-	}
+	yulAssert(false, "");
+	return {};
 }
 
 Case Parser::parseCase()

From 6c0a3bd0430fb0ddb1f1742931274c4f9d5950f6 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Thu, 5 Nov 2020 01:38:57 +0000
Subject: [PATCH 6/9] Ensure that builtins must be executed

---
 libyul/AsmParser.cpp                                           | 2 ++
 .../syntaxTests/inlineAssembly/assignment_from_opcode_like.sol | 2 +-
 test/libyul/yulSyntaxTests/builtin_identifier_3.yul            | 2 +-
 test/libyul/yulSyntaxTests/for_expr_invalid_5.yul              | 3 +--
 test/libyul/yulSyntaxTests/functional_partial.yul              | 2 +-
 test/libyul/yulSyntaxTests/if_statement_invalid_1.yul          | 3 +--
 test/libyul/yulSyntaxTests/if_statement_invalid_4.yul          | 3 +--
 test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul           | 2 +-
 8 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index e19f5b8ce..4dcc6b19a 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -256,6 +256,8 @@ Expression Parser::parseExpression()
 	{
 		if (currentToken() == Token::LParen)
 			return parseCall(std::move(operation));
+		else if (auto const& name = std::get<Identifier>(operation).name; m_dialect.builtin(name))
+			fatalParserError(7104_error, "Builtin function \"" + name.str() + "\" must be called.");
 		return std::get<Identifier>(operation);
 	}
 	else
diff --git a/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol b/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
index e9d6f1983..306604931 100644
--- a/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
+++ b/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// Warning 8261: (52-62): Variable is shadowed in inline assembly by an instruction of the same name
+// ParserError 7104: (118-119): Builtin function "mload" must be called.
diff --git a/test/libyul/yulSyntaxTests/builtin_identifier_3.yul b/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
index ece40e793..04236a8ba 100644
--- a/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
+++ b/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
@@ -2,4 +2,4 @@
 	function f(x) { f(add) }
 }
 // ----
-// DeclarationError 8198: (21-24): Identifier not found.
+// ParserError 7104: (24-25): Builtin function "add" must be called.
diff --git a/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul b/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
index 7f89fb3f4..44d8ad7c1 100644
--- a/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
+++ b/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
@@ -2,5 +2,4 @@
 	for {} mload {} {}
 }
 // ----
-// DeclarationError 8198: (10-15): Identifier not found.
-// TypeError 1733: (10-15): Expected a value of boolean type "bool" but got "u256"
+// ParserError 7104: (16-17): Builtin function "mload" must be called.
diff --git a/test/libyul/yulSyntaxTests/functional_partial.yul b/test/libyul/yulSyntaxTests/functional_partial.yul
index 5f65cb13f..1bf1c64d6 100644
--- a/test/libyul/yulSyntaxTests/functional_partial.yul
+++ b/test/libyul/yulSyntaxTests/functional_partial.yul
@@ -2,4 +2,4 @@
     let x := byte
 }
 // ----
-// DeclarationError 8198: (15-19): Identifier not found.
+// ParserError 7104: (20-21): Builtin function "byte" must be called.
diff --git a/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul b/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
index 8d40479cd..ef5e5e4da 100644
--- a/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
+++ b/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
@@ -2,5 +2,4 @@
     if mload {}
 }
 // ----
-// DeclarationError 8198: (9-14): Identifier not found.
-// TypeError 1733: (9-14): Expected a value of boolean type "bool" but got "u256"
+// ParserError 7104: (15-16): Builtin function "mload" must be called.
diff --git a/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul b/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
index 546537203..757eab328 100644
--- a/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
+++ b/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
@@ -2,5 +2,4 @@
     if calldatasize {}
 }
 // ----
-// DeclarationError 8198: (9-21): Identifier not found.
-// TypeError 1733: (9-21): Expected a value of boolean type "bool" but got "u256"
+// ParserError 7104: (22-23): Builtin function "calldatasize" must be called.
diff --git a/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul b/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
index 905b9ed1f..0886db409 100644
--- a/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
+++ b/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
@@ -4,4 +4,4 @@
     default {}
 }
 // ----
-// DeclarationError 8198: (13-18): Identifier not found.
+// ParserError 7104: (23-27): Builtin function "mload" must be called.

From 61ed1f19864e48cf092417c3db903cc41a832472 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Thu, 5 Nov 2020 11:57:01 +0000
Subject: [PATCH 7/9] cleanup

---
 libyul/AsmParser.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index 4dcc6b19a..e1bcabaf2 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -256,9 +256,14 @@ Expression Parser::parseExpression()
 	{
 		if (currentToken() == Token::LParen)
 			return parseCall(std::move(operation));
-		else if (auto const& name = std::get<Identifier>(operation).name; m_dialect.builtin(name))
-			fatalParserError(7104_error, "Builtin function \"" + name.str() + "\" must be called.");
-		return std::get<Identifier>(operation);
+		auto identifier = std::get<Identifier>(operation);
+		if (m_dialect.builtin(identifier.name))
+			fatalParserError(
+				7104_error,
+				identifier.location,
+				"Builtin function \"" + identifier.name.str() + "\" must be called."
+			);
+		return identifier;
 	}
 	else
 	{

From a9be2e4bb8952011bab8bd6bc5382057e500f6ba Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Mon, 9 Nov 2020 23:38:08 +0000
Subject: [PATCH 8/9] update tests

---
 .../syntaxTests/inlineAssembly/assignment_from_opcode_like.sol  | 2 +-
 test/libyul/yulSyntaxTests/builtin_identifier_3.yul             | 2 +-
 test/libyul/yulSyntaxTests/for_expr_invalid_5.yul               | 2 +-
 test/libyul/yulSyntaxTests/functional_partial.yul               | 2 +-
 test/libyul/yulSyntaxTests/if_statement_invalid_1.yul           | 2 +-
 test/libyul/yulSyntaxTests/if_statement_invalid_4.yul           | 2 +-
 test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul            | 2 +-
 7 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol b/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
index 306604931..cb675ab29 100644
--- a/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
+++ b/test/libsolidity/syntaxTests/inlineAssembly/assignment_from_opcode_like.sol
@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// ParserError 7104: (118-119): Builtin function "mload" must be called.
+// ParserError 7104: (104-109): Builtin function "mload" must be called.
diff --git a/test/libyul/yulSyntaxTests/builtin_identifier_3.yul b/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
index 04236a8ba..c7969b8ef 100644
--- a/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
+++ b/test/libyul/yulSyntaxTests/builtin_identifier_3.yul
@@ -2,4 +2,4 @@
 	function f(x) { f(add) }
 }
 // ----
-// ParserError 7104: (24-25): Builtin function "add" must be called.
+// ParserError 7104: (21-24): Builtin function "add" must be called.
diff --git a/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul b/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
index 44d8ad7c1..5d739e81e 100644
--- a/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
+++ b/test/libyul/yulSyntaxTests/for_expr_invalid_5.yul
@@ -2,4 +2,4 @@
 	for {} mload {} {}
 }
 // ----
-// ParserError 7104: (16-17): Builtin function "mload" must be called.
+// ParserError 7104: (10-15): Builtin function "mload" must be called.
diff --git a/test/libyul/yulSyntaxTests/functional_partial.yul b/test/libyul/yulSyntaxTests/functional_partial.yul
index 1bf1c64d6..ea28283d4 100644
--- a/test/libyul/yulSyntaxTests/functional_partial.yul
+++ b/test/libyul/yulSyntaxTests/functional_partial.yul
@@ -2,4 +2,4 @@
     let x := byte
 }
 // ----
-// ParserError 7104: (20-21): Builtin function "byte" must be called.
+// ParserError 7104: (15-19): Builtin function "byte" must be called.
diff --git a/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul b/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
index ef5e5e4da..0a4f33844 100644
--- a/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
+++ b/test/libyul/yulSyntaxTests/if_statement_invalid_1.yul
@@ -2,4 +2,4 @@
     if mload {}
 }
 // ----
-// ParserError 7104: (15-16): Builtin function "mload" must be called.
+// ParserError 7104: (9-14): Builtin function "mload" must be called.
diff --git a/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul b/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
index 757eab328..b84004a8d 100644
--- a/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
+++ b/test/libyul/yulSyntaxTests/if_statement_invalid_4.yul
@@ -2,4 +2,4 @@
     if calldatasize {}
 }
 // ----
-// ParserError 7104: (22-23): Builtin function "calldatasize" must be called.
+// ParserError 7104: (9-21): Builtin function "calldatasize" must be called.
diff --git a/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul b/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
index 0886db409..9378297ca 100644
--- a/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
+++ b/test/libyul/yulSyntaxTests/switch_invalid_expr_2.yul
@@ -4,4 +4,4 @@
     default {}
 }
 // ----
-// ParserError 7104: (23-27): Builtin function "mload" must be called.
+// ParserError 7104: (13-18): Builtin function "mload" must be called.

From 5071709b2593cf9f7b15e1f8f3b84b2a5a6388ca Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Thu, 3 Dec 2020 17:44:11 +0100
Subject: [PATCH 9/9] Remove FunctionCall from ElementaryOperation.

---
 libyul/AsmParser.cpp | 57 ++++++++++++++++++++++----------------------
 libyul/AsmParser.h   |  6 ++---
 2 files changed, 30 insertions(+), 33 deletions(-)

diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index e1bcabaf2..c43066ee0 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -27,6 +27,7 @@
 #include <liblangutil/Scanner.h>
 #include <liblangutil/ErrorReporter.h>
 #include <libsolutil/Common.h>
+#include <libsolutil/Visitor.h>
 
 #include <boost/algorithm/string.hpp>
 
@@ -142,7 +143,7 @@ Statement Parser::parseStatement()
 	// Options left:
 	// Expression/FunctionCall
 	// Assignment
-	ElementaryOperation elementary(parseLiteralOrIdentifier());
+	variant<Literal, Identifier> elementary(parseLiteralOrIdentifier());
 
 	switch (currentToken())
 	{
@@ -212,7 +213,7 @@ Case Parser::parseCase()
 	else if (currentToken() == Token::Case)
 	{
 		advance();
-		ElementaryOperation literal = parseLiteralOrIdentifier();
+		variant<Literal, Identifier> literal = parseLiteralOrIdentifier();
 		if (!holds_alternative<Literal>(literal))
 			fatalParserError(4805_error, "Literal expected.");
 		_case.value = make_unique<Literal>(std::get<Literal>(std::move(literal)));
@@ -251,38 +252,37 @@ Expression Parser::parseExpression()
 {
 	RecursionGuard recursionGuard(*this);
 
-	ElementaryOperation operation = parseLiteralOrIdentifier();
-	if (holds_alternative<Identifier>(operation))
-	{
-		if (currentToken() == Token::LParen)
-			return parseCall(std::move(operation));
-		auto identifier = std::get<Identifier>(operation);
-		if (m_dialect.builtin(identifier.name))
-			fatalParserError(
-				7104_error,
-				identifier.location,
-				"Builtin function \"" + identifier.name.str() + "\" must be called."
-			);
-		return identifier;
-	}
-	else
-	{
-		yulAssert(holds_alternative<Literal>(operation), "");
-		return std::get<Literal>(operation);
-	}
+	variant<Literal, Identifier> operation = parseLiteralOrIdentifier();
+	return visit(GenericVisitor{
+		[&](Identifier& _identifier) -> Expression
+		{
+			if (currentToken() == Token::LParen)
+				return parseCall(std::move(operation));
+			if (m_dialect.builtin(_identifier.name))
+				fatalParserError(
+					7104_error,
+					_identifier.location,
+					"Builtin function \"" + _identifier.name.str() + "\" must be called."
+				);
+			return move(_identifier);
+		},
+		[&](Literal& _literal) -> Expression
+		{
+			return move(_literal);
+		}
+	}, operation);
 }
 
-Parser::ElementaryOperation Parser::parseLiteralOrIdentifier()
+variant<Literal, Identifier> Parser::parseLiteralOrIdentifier()
 {
 	RecursionGuard recursionGuard(*this);
-	ElementaryOperation ret;
 	switch (currentToken())
 	{
 	case Token::Identifier:
 	{
-		ret = Identifier{currentLocation(), YulString{currentLiteral()}};
+		Identifier identifier{currentLocation(), YulString{currentLiteral()}};
 		advance();
-		break;
+		return identifier;
 	}
 	case Token::StringLiteral:
 	case Token::Number:
@@ -322,8 +322,7 @@ Parser::ElementaryOperation Parser::parseLiteralOrIdentifier()
 			literal.type = expectAsmIdentifier();
 		}
 
-		ret = std::move(literal);
-		break;
+		return literal;
 	}
 	case Token::HexStringLiteral:
 		fatalParserError(3772_error, "Hex literals are not valid in this context.");
@@ -331,7 +330,7 @@ Parser::ElementaryOperation Parser::parseLiteralOrIdentifier()
 	default:
 		fatalParserError(1856_error, "Literal or identifier expected.");
 	}
-	return ret;
+	return {};
 }
 
 VariableDeclaration Parser::parseVariableDeclaration()
@@ -405,7 +404,7 @@ FunctionDefinition Parser::parseFunctionDefinition()
 	return funDef;
 }
 
-FunctionCall Parser::parseCall(Parser::ElementaryOperation&& _initialOp)
+FunctionCall Parser::parseCall(variant<Literal, Identifier>&& _initialOp)
 {
 	RecursionGuard recursionGuard(*this);
 
diff --git a/libyul/AsmParser.h b/libyul/AsmParser.h
index 2dcbcd191..d1294b111 100644
--- a/libyul/AsmParser.h
+++ b/libyul/AsmParser.h
@@ -61,8 +61,6 @@ public:
 	std::unique_ptr<Block> parse(std::shared_ptr<langutil::Scanner> const& _scanner, bool _reuseScanner);
 
 protected:
-	using ElementaryOperation = std::variant<Literal, Identifier, FunctionCall>;
-
 	langutil::SourceLocation currentLocation() const override
 	{
 		return m_locationOverride ? *m_locationOverride : ParserBase::currentLocation();
@@ -84,10 +82,10 @@ protected:
 	Expression parseExpression();
 	/// Parses an elementary operation, i.e. a literal, identifier, instruction or
 	/// builtin functian call (only the name).
-	ElementaryOperation parseLiteralOrIdentifier();
+	std::variant<Literal, Identifier> parseLiteralOrIdentifier();
 	VariableDeclaration parseVariableDeclaration();
 	FunctionDefinition parseFunctionDefinition();
-	FunctionCall parseCall(ElementaryOperation&& _initialOp);
+	FunctionCall parseCall(std::variant<Literal, Identifier>&& _initialOp);
 	TypedName parseTypedName();
 	YulString expectAsmIdentifier();