Add new reserved keywords. Closes #2182.

Author: ekpyron

libsolidity/parsing/Token.h

@@ -221,22 +221,43 @@ namespace solidity
 	/* Keywords reserved for future use. */                            \
 	K(Abstract, "abstract", 0)                                         \
 	K(After, "after", 0)                                               \
+	K(Alias, "alias", 0)                                               \
+	K(Apply, "apply", 0)                                               \
+	K(Auto, "auto", 0)                                                 \
 	K(Case, "case", 0)                                                 \
 	K(Catch, "catch", 0)                                               \
+	K(Const, "const", 0)                                               \
+	K(Constructor, "constructor", 0)                                   \
 	K(Default, "default", 0)                                           \
+	K(Define, "define", 0)                                             \
+	K(Fallback, "fallback", 0)                                         \
 	K(Final, "final", 0)                                               \
+	K(Immutable, "immutable", 0)                                       \
+	K(Implements, "implements", 0)                                     \
 	K(In, "in", 0)                                                     \
 	K(Inline, "inline", 0)                                             \
 	K(Let, "let", 0)                                                   \
+	K(Macro, "macro", 0)                                               \
 	K(Match, "match", 0)                                               \
+	K(Mutable, "mutable", 0)                                           \
 	K(NullLiteral, "null", 0)                                          \
 	K(Of, "of", 0)                                                     \
+	K(Override, "override", 0)                                         \
+	K(Promise, "promise", 0)                                           \
+	K(Reference, "reference", 0)                                       \
 	K(Relocatable, "relocatable", 0)                                   \
+	K(Sealed, "sealed", 0)                                             \
+	K(Sizeof, "sizeof", 0)                                             \
 	K(Static, "static", 0)                                             \
+	K(Supports, "supports", 0)                                         \
 	K(Switch, "switch", 0)                                             \
+	K(Topic, "topic", 0)                                               \
 	K(Try, "try", 0)                                                   \
 	K(Type, "type", 0)                                                 \
+	K(Typedef, "typedef", 0)                                           \
 	K(TypeOf, "typeof", 0)                                             \
+	K(Unchecked, "unchecked", 0)                                       \
+	\
 	/* Illegal token - not able to scan. */                            \
 	T(Illegal, "ILLEGAL", 0)                                           \
 	\

test/libsolidity/SolidityParser.cpp

@@ -1164,6 +1164,56 @@ BOOST_AUTO_TEST_CASE(constant_is_keyword)
 	CHECK_PARSE_ERROR(text, "Expected identifier");
 }
 
+BOOST_AUTO_TEST_CASE(keyword_is_reserved)
+{
+	auto keywords = {
+		"abstract",
+		"after",
+		"alias",
+		"apply",
+		"auto",
+		"case",
+		"catch",
+		"const",
+		"constructor",
+		"default",
+		"define",
+		"fallback",
+		"final",
+		"immutable",
+		"implements",
+		"in",
+		"inline",
+		"let",
+		"macro",
+		"match",
+		"mutable",
+		"null",
+		"of",
+		"override",
+		"promise",
+		"reference",
+		"relocatable",
+		"sealed",
+		"sizeof",
+		"static",
+		"supports",
+		"switch",
+		"topic",
+		"try",
+		"type",
+		"typedef",
+		"typeof",
+		"unchecked"
+	};
+	
+
+	for (const auto& keyword : keywords) {
+		auto text = std::string("contract ") + keyword + " {}";
+		CHECK_PARSE_ERROR(text.c_str(), "Expected identifier");
+	}
+}
+
 BOOST_AUTO_TEST_CASE(var_array)
 {
 	char const* text = R"(