Expose hex literal to the Yul parser

This allows nicer error messages.

liblangutil/Scanner.cpp

@@ -668,7 +668,7 @@ void Scanner::scanToken()
 				tie(token, m, n) = scanIdentifierOrKeyword();
 
 				// Special case for hexadecimal literals
-				if (token == Token::Hex && m_kind != ScannerKind::Yul)
+				if (token == Token::Hex)
 				{
 					// reset
 					m = 0;

liblangutil/Token.h

@@ -324,7 +324,7 @@ namespace TokenTraits
 	{
 		return tok == Token::Function || tok == Token::Let || tok == Token::If || tok == Token::Switch || tok == Token::Case ||
 			tok == Token::Default || tok == Token::For || tok == Token::Break || tok == Token::Continue || tok == Token::Leave ||
-			tok == Token::TrueLiteral || tok == Token::FalseLiteral;
+			tok == Token::TrueLiteral || tok == Token::FalseLiteral || tok == Token::HexStringLiteral || tok == Token::Hex;
 	}
 
 	inline Token AssignmentToBinaryOp(Token op)

libyul/AsmParser.cpp

@@ -337,6 +337,9 @@ Parser::ElementaryOperation Parser::parseElementaryOperation()
 		ret = std::move(literal);
 		break;
 	}
+	case Token::HexStringLiteral:
+		fatalParserError(3772_error, "Hex literals are not valid in this context.");
+		break;
 	default:
 		fatalParserError(1856_error, "Literal or identifier expected.");
 	}

test/liblangutil/Scanner.cpp

@@ -652,9 +652,8 @@ BOOST_AUTO_TEST_CASE(hex_prefix_only)
 	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalToken);
 	scanner.reset(CharStream("{ hex", ""));
 	scanner.setScannerMode(ScannerKind::Yul);
-	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
+	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
-	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
+	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalToken);
-	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "hex");
 }
 
 BOOST_AUTO_TEST_CASE(hex_invalid_space)
@@ -674,10 +673,8 @@ BOOST_AUTO_TEST_CASE(hex_invalid_token)
 	scanner.reset(CharStream("{ hex test", ""));
 	scanner.setScannerMode(ScannerKind::Yul);
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
-	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
+	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
-	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "hex");
+	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalToken);
-	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
-	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "test");
 }
 
 BOOST_AUTO_TEST_CASE(valid_hex_literal)

test/libsolidity/syntaxTests/inlineAssembly/hex_assignment.sol

@@ -6,4 +6,4 @@ contract C {
   }
 }
 // ----
-// ParserError 6913: (86-87): Call or assignment expected.
+// ParserError 3772: (72-81): Hex literals are not valid in this context.

test/libsolidity/syntaxTests/inlineAssembly/hex_expression.sol

@@ -6,4 +6,4 @@ contract C {
   }
 }
 // ----
-// ParserError 2314: (70-76): Expected ',' but got 'StringLiteral'
+// ParserError 3772: (67-76): Hex literals are not valid in this context.

test/libsolidity/syntaxTests/inlineAssembly/hex_switch_case.sol

@@ -8,4 +8,4 @@ contract C {
   }
 }
 // ----
-// ParserError 4805: (95-99): Literal expected.
+// ParserError 3772: (92-99): Hex literals are not valid in this context.

test/libsolidity/syntaxTests/inlineAssembly/solidity_keywords.sol

@@ -21,7 +21,7 @@ contract C {
   let fallback := 1
   // for is a Yul keyword
   // function is a Yul keyword
-  let hex := 1
+  // hex is a Yul keyword
   // if is a Yul keyword
   let indexed := 1
   let interface := 1
@@ -110,4 +110,4 @@ contract C {
   }
 }
 // ----
-// Warning 5740: (944-2157): Unreachable code.
+// Warning 5740: (955-2168): Unreachable code.

test/libyul/yulSyntaxTests/hex_assignment.yul

@@ -2,4 +2,4 @@
     let x := hex"0011"
 }
 // ----
-// ParserError 6913: (25-26): Call or assignment expected.
+// ParserError 3772: (15-24): Hex literals are not valid in this context.

test/libyul/yulSyntaxTests/hex_expression.yul

@@ -2,4 +2,4 @@
     pop(hex"2233")
 }
 // ----
-// ParserError 2314: (13-19): Expected ',' but got 'StringLiteral'
+// ParserError 3772: (10-19): Hex literals are not valid in this context.

test/libyul/yulSyntaxTests/hex_switch_case.yul

@@ -4,4 +4,4 @@
     case hex"1122" {}
 }
 // ----
-// ParserError 4805: (36-40): Literal expected.
+// ParserError 3772: (33-40): Hex literals are not valid in this context.

test/libyul/yulSyntaxTests/solidity_keywords.yul

@@ -19,7 +19,7 @@
   let fallback := 1
   // for is a Yul keyword
   // function is a Yul keyword
-  let hex := 1
+  // hex is a Yul keyword
   // if is a Yul keyword
   let indexed := 1
   let interface := 1