parser: Allow to begin expression with statement keywordwip/issue/1073

Fixes https://gitlab.gnome.org/GNOME/vala/issues/1073

3 files changed, 179 insertions, 47 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0f636c50c..5d7cc13ab 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -760,6 +760,7 @@ TESTS = \
 	parser/qualified-symbol-access.vala \
 	parser/signal-no-class.test \
 	parser/signal-no-static.test \
+	parser/statement-keyword-as-identifier.vala \
 	parser/statement-outside-root.test \
 	parser/switch-statement.vala \
 	parser/template.vala \
diff --git a/tests/parser/statement-keyword-as-identifier.vala b/tests/parser/statement-keyword-as-identifier.vala
new file mode 100644
index 000000000..a88f11e46
--- /dev/null
+++ b/tests/parser/statement-keyword-as-identifier.vala
@@ -0,0 +1,85 @@
+void main () {
+	{
+		int if;
+		if = 1;
+		assert (if == 1);
+	}
+	{
+		int switch;
+		switch = 2;
+		assert (switch == 2);
+	}
+	{
+		int while;
+		while = 3;
+		assert (while == 3);
+	}
+	{
+		int do;
+		do = 4;
+		assert (do == 4);
+	}
+	{
+		int for;
+		for = 5;
+		assert (for == 5);
+	}
+	{
+		int foreach;
+		foreach = 6;
+		assert (foreach == 6);
+	}
+	{
+		//FIXME
+		//int break;
+		//break = 7;
+		//assert (break == 7);
+	}
+	{
+		//FIXME
+		//int continue;
+		//continue = 8;
+		//assert (continue == 8);
+	}
+	{
+		int return;
+		return = 9;
+		assert (return == 9);
+	}
+	{
+		//FIXME
+		//int yield;
+		//yield = 10;
+		//assert (yield == 10);
+	}
+	{
+		int throw;
+		throw = 11;
+		assert (throw == 11);
+	}
+	{
+		int try;
+		try = 12;
+		assert (try == 12);
+	}
+	{
+		int lock;
+		lock = 13;
+		assert (lock == 13);
+	}
+	{
+		int unlock;
+		unlock = 14;
+		assert (unlock == 14);
+	}
+	{
+		int delete;
+		delete = 15;
+		assert (delete == 15);
+	}
+	{
+		int with;
+		with = 16;
+		assert (with == 16);
+	}
+}
diff --git a/vala/valaparser.vala b/vala/valaparser.vala
index 216cd0a7d..74cf0f2f4 100644
--- a/vala/valaparser.vala
+++ b/vala/valaparser.vala
@@ -1584,6 +1584,81 @@ public class Vala.Parser : CodeVisitor {
 		return expr;
 	}
 
+	Statement? parse_statement (TokenType type) throws ParseError {
+		Statement? stmt = null;
+		var begin = get_location ();
+		try {
+			switch (type) {
+			case TokenType.IF:
+				stmt = parse_if_statement ();
+				break;
+			case TokenType.SWITCH:
+				stmt = parse_switch_statement ();
+				break;
+			case TokenType.WHILE:
+				stmt = parse_while_statement ();
+				break;
+			case TokenType.DO:
+				stmt = parse_do_statement ();
+				break;
+			case TokenType.FOR:
+				stmt = parse_for_statement ();
+				break;
+			case TokenType.FOREACH:
+				stmt = parse_foreach_statement ();
+				break;
+			case TokenType.BREAK:
+				stmt = parse_break_statement ();
+				break;
+			case TokenType.CONTINUE:
+				stmt = parse_continue_statement ();
+				break;
+			case TokenType.RETURN:
+				stmt = parse_return_statement ();
+				break;
+			case TokenType.YIELD:
+				stmt = parse_yield_statement ();
+				break;
+			case TokenType.THROW:
+				stmt = parse_throw_statement ();
+				break;
+			case TokenType.TRY:
+				stmt = parse_try_statement ();
+				break;
+			case TokenType.LOCK:
+				stmt = parse_lock_statement ();
+				break;
+			case TokenType.UNLOCK:
+				stmt = parse_unlock_statement ();
+				break;
+			case TokenType.DELETE:
+				stmt = parse_delete_statement ();
+				break;
+			case TokenType.WITH:
+				stmt = parse_with_statement ();
+				break;
+			default:
+				assert_not_reached ();
+			}
+		} catch (ParseError e) {
+			var e_begin = get_location ();
+			string token = ((EnumClass) typeof (TokenType).class_ref ()).get_value (type).value_nick;
+			try {
+				rollback (begin);
+				stmt = parse_expression_statement ();
+				Report.warning (get_src (begin), "`%s' is a syntax keyword, replace with `@%s'".printf (token, token));
+			} catch (ParseError e2) {
+				var e2_begin = get_location ();
+				rollback (e_begin);
+				next ();
+				Report.error (get_src (e_begin), "Possible `%s-statement' syntax error, %s".printf (token, e.message));
+				rollback (e2_begin);
+				throw e2;
+			}
+		}
+		return stmt;
+	}
+
 	void parse_statements (Block block) throws ParseError {
 		while (current () != TokenType.CLOSE_BRACE
 		       && current () != TokenType.CASE
@@ -1602,52 +1677,22 @@ public class Vala.Parser : CodeVisitor {
 					stmt = parse_empty_statement ();
 					break;
 				case TokenType.IF:
-					stmt = parse_if_statement ();
-					break;
 				case TokenType.SWITCH:
-					stmt = parse_switch_statement ();
-					break;
 				case TokenType.WHILE:
-					stmt = parse_while_statement ();
-					break;
 				case TokenType.DO:
-					stmt = parse_do_statement ();
-					break;
 				case TokenType.FOR:
-					stmt = parse_for_statement ();
-					break;
 				case TokenType.FOREACH:
-					stmt = parse_foreach_statement ();
-					break;
 				case TokenType.BREAK:
-					stmt = parse_break_statement ();
-					break;
 				case TokenType.CONTINUE:
-					stmt = parse_continue_statement ();
-					break;
 				case TokenType.RETURN:
-					stmt = parse_return_statement ();
-					break;
 				case TokenType.YIELD:
-					stmt = parse_yield_statement ();
-					break;
 				case TokenType.THROW:
-					stmt = parse_throw_statement ();
-					break;
 				case TokenType.TRY:
-					stmt = parse_try_statement ();
-					break;
 				case TokenType.LOCK:
-					stmt = parse_lock_statement ();
-					break;
 				case TokenType.UNLOCK:
-					stmt = parse_unlock_statement ();
-					break;
 				case TokenType.DELETE:
-					stmt = parse_delete_statement ();
-					break;
 				case TokenType.WITH:
-					stmt = parse_with_statement ();
+					stmt = parse_statement (current ());
 					break;
 				case TokenType.VAR:
 					is_decl = true;
@@ -1821,22 +1866,23 @@ public class Vala.Parser : CodeVisitor {
 				Report.warning (get_current_src (), "%s-statement without body".printf (statement_name));
 			}
 			return parse_empty_statement ();
-		case TokenType.IF:        return parse_if_statement ();
-		case TokenType.SWITCH:    return parse_switch_statement ();
-		case TokenType.WHILE:     return parse_while_statement ();
-		case TokenType.DO:        return parse_do_statement ();
-		case TokenType.FOR:       return parse_for_statement ();
-		case TokenType.FOREACH:   return parse_foreach_statement ();
-		case TokenType.BREAK:     return parse_break_statement ();
-		case TokenType.CONTINUE:  return parse_continue_statement ();
-		case TokenType.RETURN:    return parse_return_statement ();
-		case TokenType.YIELD:     return parse_yield_statement ();
-		case TokenType.THROW:     return parse_throw_statement ();
-		case TokenType.TRY:       return parse_try_statement ();
-		case TokenType.LOCK:      return parse_lock_statement ();
-		case TokenType.UNLOCK:    return parse_unlock_statement ();
-		case TokenType.DELETE:    return parse_delete_statement ();
-		case TokenType.WITH:      return parse_with_statement ();
+		case TokenType.IF:
+		case TokenType.SWITCH:
+		case TokenType.WHILE:
+		case TokenType.DO:
+		case TokenType.FOR:
+		case TokenType.FOREACH:
+		case TokenType.BREAK:
+		case TokenType.CONTINUE:
+		case TokenType.RETURN:
+		case TokenType.YIELD:
+		case TokenType.THROW:
+		case TokenType.TRY:
+		case TokenType.LOCK:
+		case TokenType.UNLOCK:
+		case TokenType.DELETE:
+		case TokenType.WITH:
+			return parse_statement (current ());
 		case TokenType.VAR:
 		case TokenType.CONST:
 			throw new ParseError.SYNTAX ("embedded statement cannot be declaration ");