From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Wed, 25 Apr 2018 14:08:06 +0000 (+0200)
Subject: parser: Add support for explicit "unlock" syntax
X-Git-Tag: 0.41.90~154
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8898e125d66455b0e072dc563e27998cf7a75f73;p=thirdparty%2Fvala.git

parser: Add support for explicit "unlock" syntax

By providing more control over the internal support for Mutex creation and
usage, this allows a more complex resource control while having an explicit
way to unlock a previously locked lockable.

  lock (foo);
  ...
  unlock (foo);

https://bugzilla.gnome.org/show_bug.cgi?id=795545
---

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 025d0f891..134369b6c 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -420,6 +420,7 @@ TESTS = \
 	parser/function-syntax-error.test \
 	parser/inner-array-size.test \
 	parser/invalid-brace.test \
+	parser/lock-statement.vala \
 	parser/method-no-abstract-override.test \
 	parser/method-no-abstract-virtual-override.test \
 	parser/method-no-abstract-virtual.test \
diff --git a/tests/parser/lock-statement.vala b/tests/parser/lock-statement.vala
new file mode 100644
index 000000000..65d9d82b6
--- /dev/null
+++ b/tests/parser/lock-statement.vala
@@ -0,0 +1,19 @@
+class Foo {
+	int lockable;
+
+	public void explicit_unlocking () {
+		lock (lockable);
+		unlock (lockable);
+	}
+
+	public void implicit_unlocking () {
+		lock (lockable) {
+		}
+	}
+}
+
+void main () {
+	var foo = new Foo ();
+	foo.explicit_unlocking ();
+	foo.implicit_unlocking ();
+}
diff --git a/vala/valaparser.vala b/vala/valaparser.vala
index 3df315d1f..eca5565cf 100644
--- a/vala/valaparser.vala
+++ b/vala/valaparser.vala
@@ -238,6 +238,7 @@ public class Vala.Parser : CodeVisitor {
 		case TokenType.TRUE:
 		case TokenType.TRY:
 		case TokenType.TYPEOF:
+		case TokenType.UNLOCK:
 		case TokenType.UNOWNED:
 		case TokenType.USING:
 		case TokenType.VAR:
@@ -1576,6 +1577,9 @@ public class Vala.Parser : CodeVisitor {
 				case TokenType.LOCK:
 					stmt = parse_lock_statement ();
 					break;
+				case TokenType.UNLOCK:
+					stmt = parse_unlock_statement ();
+					break;
 				case TokenType.DELETE:
 					stmt = parse_delete_statement ();
 					break;
@@ -1740,6 +1744,7 @@ public class Vala.Parser : CodeVisitor {
 		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.VAR:
 		case TokenType.CONST:
@@ -2134,10 +2139,23 @@ public class Vala.Parser : CodeVisitor {
 		expect (TokenType.OPEN_PARENS);
 		var expr = parse_expression ();
 		expect (TokenType.CLOSE_PARENS);
-		var stmt = parse_embedded_statement ("lock", false);
+		Block? stmt = null;
+		if (current () != TokenType.SEMICOLON) {
+			stmt = parse_embedded_statement ("lock", false);
+		}
 		return new LockStatement (expr, stmt, get_src (begin));
 	}
 
+	Statement parse_unlock_statement () throws ParseError {
+		var begin = get_location ();
+		expect (TokenType.UNLOCK);
+		expect (TokenType.OPEN_PARENS);
+		var expr = parse_expression ();
+		expect (TokenType.CLOSE_PARENS);
+		expect (TokenType.SEMICOLON);
+		return new UnlockStatement (expr, get_src (begin));
+	}
+
 	Statement parse_delete_statement () throws ParseError {
 		var begin = get_location ();
 		expect (TokenType.DELETE);
@@ -2265,6 +2283,7 @@ public class Vala.Parser : CodeVisitor {
 		case TokenType.THROW:
 		case TokenType.TRY:
 		case TokenType.LOCK:
+		case TokenType.UNLOCK:
 		case TokenType.DELETE:
 		case TokenType.VAR:
 		case TokenType.OP_INC:
@@ -2450,6 +2469,7 @@ public class Vala.Parser : CodeVisitor {
 			case TokenType.SWITCH:
 			case TokenType.THROW:
 			case TokenType.TRY:
+			case TokenType.UNLOCK:
 			case TokenType.VAR:
 			case TokenType.WHILE:
 			case TokenType.YIELD:
diff --git a/vala/valascanner.vala b/vala/valascanner.vala
index 8b50a59d4..2cb705064 100644
--- a/vala/valascanner.vala
+++ b/vala/valascanner.vala
@@ -473,6 +473,9 @@ public class Vala.Scanner {
 					break;
 				}
 				break;
+			case 'u':
+				if (matches (begin, "unlock")) return TokenType.UNLOCK;
+				break;
 			}
 			break;
 		case 7:
diff --git a/vala/valatokentype.vala b/vala/valatokentype.vala
index a3867f5fb..38be631b7 100644
--- a/vala/valatokentype.vala
+++ b/vala/valatokentype.vala
@@ -143,6 +143,7 @@ public enum Vala.TokenType {
 	TRUE,
 	TRY,
 	TYPEOF,
+	UNLOCK,
 	UNOWNED,
 	USING,
 	VAR,
@@ -275,6 +276,7 @@ public enum Vala.TokenType {
 		case TRUE: return "`true'";
 		case TRY: return "`try'";
 		case TYPEOF: return "`typeof'";
+		case UNLOCK: return "`unlock'";
 		case UNOWNED: return "`unowned'";
 		case USING: return "`using'";
 		case VAR: return "`var'";