vala: Add Expression.is_always_true/false() helpers

5 files changed, 23 insertions, 42 deletions

diff --git a/vala/valadostatement.vala b/vala/valadostatement.vala
index d994b5abd..80df5849e 100644
--- a/vala/valadostatement.vala
+++ b/vala/valadostatement.vala
@@ -81,11 +81,6 @@ public class Vala.DoStatement : CodeNode, Statement {
 		visitor.visit_end_full_expression (condition);
 	}
 
-	bool always_true (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && literal.value);
-	}
-
 	public override void replace_expression (Expression old_node, Expression new_node) {
 		if (condition == old_node) {
 			condition = new_node;
@@ -102,7 +97,7 @@ public class Vala.DoStatement : CodeNode, Statement {
 		// convert to simple loop
 
 		// do not generate variable and if block if condition is always true
-		if (always_true (condition)) {
+		if (condition.is_always_true ()) {
 			var loop = new Loop (body, source_reference);
 
 			unowned Block parent_block = (Block) parent_node;
diff --git a/vala/valaexpression.vala b/vala/valaexpression.vala
index 2b9170e42..a02cc1c1f 100644
--- a/vala/valaexpression.vala
+++ b/vala/valaexpression.vala
@@ -86,6 +86,22 @@ public abstract class Vala.Expression : CodeNode {
 		return true;
 	}
 
+	/**
+	 * Check whether this expression is always true.
+	 */
+	public bool is_always_true () {
+		unowned BooleanLiteral? literal = this as BooleanLiteral;
+		return (literal != null && literal.value);
+	}
+
+	/**
+	 * Check whether this expression is always false.
+	 */
+	public bool is_always_false () {
+		unowned BooleanLiteral? literal = this as BooleanLiteral;
+		return (literal != null && !literal.value);
+	}
+
 	public Statement? parent_statement {
 		get {
 			unowned Expression? expr = parent_node as Expression;
diff --git a/vala/valaflowanalyzer.vala b/vala/valaflowanalyzer.vala
index 03aae237f..ea0df7a83 100644
--- a/vala/valaflowanalyzer.vala
+++ b/vala/valaflowanalyzer.vala
@@ -599,16 +599,6 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 		}
 	}
 
-	bool always_true (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && literal.value);
-	}
-
-	bool always_false (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && !literal.value);
-	}
-
 	public override void visit_if_statement (IfStatement stmt) {
 		if (unreachable (stmt)) {
 			return;
@@ -621,7 +611,7 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 
 		// true block
 		var last_block = current_block;
-		if (always_false (stmt.condition)) {
+		if (stmt.condition.is_always_false ()) {
 			mark_unreachable ();
 		} else {
 			current_block = new BasicBlock ();
@@ -632,7 +622,7 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 
 		// false block
 		var last_true_block = current_block;
-		if (always_true (stmt.condition)) {
+		if (stmt.condition.is_always_true ()) {
 			mark_unreachable ();
 		} else {
 			current_block = new BasicBlock ();
diff --git a/vala/valaforstatement.vala b/vala/valaforstatement.vala
index e5276975b..dc721163c 100644
--- a/vala/valaforstatement.vala
+++ b/vala/valaforstatement.vala
@@ -154,16 +154,6 @@ public class Vala.ForStatement : CodeNode, Statement {
 		}
 	}
 
-	bool always_true (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && literal.value);
-	}
-
-	bool always_false (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && !literal.value);
-	}
-
 	public override bool check (CodeContext context) {
 		if (checked) {
 			return !error;
@@ -181,8 +171,8 @@ public class Vala.ForStatement : CodeNode, Statement {
 		}
 
 		// do not generate if block if condition is always true
-		if (condition == null || always_true (condition)) {
-		} else if (always_false (condition)) {
+		if (condition == null || condition.is_always_true ()) {
+		} else if (condition.is_always_false ()) {
 			// do not generate if block if condition is always false
 			body.insert_statement (0, new BreakStatement (condition.source_reference));
 		} else {
diff --git a/vala/valawhilestatement.vala b/vala/valawhilestatement.vala
index 9c333960a..161252219 100644
--- a/vala/valawhilestatement.vala
+++ b/vala/valawhilestatement.vala
@@ -81,16 +81,6 @@ public class Vala.WhileStatement : CodeNode, Statement {
 		body.accept (visitor);
 	}
 
-	bool always_true (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && literal.value);
-	}
-
-	bool always_false (Expression condition) {
-		unowned BooleanLiteral? literal = condition as BooleanLiteral;
-		return (literal != null && !literal.value);
-	}
-
 	public override void replace_expression (Expression old_node, Expression new_node) {
 		if (condition == old_node) {
 			condition = new_node;
@@ -106,9 +96,9 @@ public class Vala.WhileStatement : CodeNode, Statement {
 
 		// convert to simple loop
 
-		if (always_true (condition)) {
+		if (condition.is_always_true ()) {
 			// do not generate if block if condition is always true
-		} else if (always_false (condition)) {
+		} else if (condition.is_always_false ()) {
 			// do not generate if block if condition is always false
 			body.insert_statement (0, new BreakStatement (condition.source_reference));
 		} else {