>From 7b58ecb6c242e6a4b0ba6867117968b2986d6230 Mon Sep 17 00:00:00 2001
From: Yu Feng <rainwoodman localhost localdomain>
Date: Fri, 26 Jun 2009 10:01:29 +0800
Subject: [PATCH] Deduces is_all_constant in switch statements

Currently non-constant case labels are not supported.
---
 vala/valaswitchlabel.vala     |   10 +++++++++-
 vala/valaswitchsection.vala   |   12 ++++++++++++
 vala/valaswitchstatement.vala |   20 ++++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletions(-)

diff --git a/vala/valaswitchlabel.vala b/vala/valaswitchlabel.vala
index a778ce2..67cb16c 100644
--- a/vala/valaswitchlabel.vala
+++ b/vala/valaswitchlabel.vala
@@ -65,11 +65,19 @@ public class Vala.SwitchLabel : CodeNode {
 		}
 	}
 	
+	/* for default label this flag is also true */
+	private bool _is_constant = true;
+
 	public override bool check (SemanticAnalyzer analyzer) {
 		if (expression != null) {
 			expression.check (analyzer);
+			_is_constant = expression.is_constant();
 		}
-
+		
 		return true;
 	}
+
+	public bool is_constant () {
+		return _is_constant;
+	}
 }
diff --git a/vala/valaswitchsection.vala b/vala/valaswitchsection.vala
index 27c02c2..bacad15 100644
--- a/vala/valaswitchsection.vala
+++ b/vala/valaswitchsection.vala
@@ -67,6 +67,15 @@ public class Vala.SwitchSection : Block {
 		return false;
 	}
 	
+	private bool _is_all_constant = true;
+	/**
+	 * Return if all labels are constant
+	 *
+	 * @return if all labels are constant
+	 */
+	public bool is_all_constant () {
+		return _is_all_constant;
+	}
 	public override void accept (CodeVisitor visitor) {
 		visitor.visit_switch_section (this);
 	}
@@ -90,6 +99,9 @@ public class Vala.SwitchSection : Block {
 
 		foreach (SwitchLabel label in get_labels ()) {
 			label.check (analyzer);
+			if(label.is_constant() == false) {
+				_is_all_constant = false;
+			}
 		}
 
 		owner = analyzer.current_symbol.scope;
diff --git a/vala/valaswitchstatement.vala b/vala/valaswitchstatement.vala
index a66a284..5be6fac 100644
--- a/vala/valaswitchstatement.vala
+++ b/vala/valaswitchstatement.vala
@@ -43,6 +43,7 @@ public class Vala.SwitchStatement : CodeNode, Statement {
 	private Expression _expression;
 	private Gee.List<SwitchSection> sections = new ArrayList<SwitchSection> ();
 
+	private bool _is_all_constant = true;
 	/**
 	 * Creates a new switch statement.
 	 *
@@ -74,6 +75,15 @@ public class Vala.SwitchStatement : CodeNode, Statement {
 		return new ReadOnlyList<SwitchSection> (sections);
 	}
 
+	/**
+	 * Returns if all labels can be deduced into a constant
+	 *
+	 * @return if all labels can be deduced into a constant
+	 */
+	public bool is_all_constant() {
+		return _is_all_constant;
+	}
+
 	public override void accept (CodeVisitor visitor) {
 		visitor.visit_switch_statement (this);
 	}
@@ -116,8 +126,18 @@ public class Vala.SwitchStatement : CodeNode, Statement {
 
 		foreach (SwitchSection section in sections) {
 			section.check (analyzer);
+			if(section.is_all_constant() == false) {
+				_is_all_constant = false;
+			}
 		}
 
+		if(!_is_all_constant
+		&& !expression.value_type.compatible (analyzer.string_type)) {
+			Report.error (expression.source_reference, 
+			"Non-constant case labels are not yet supported");
+			error = true;
+			return false;
+		}
 		return !error;
 	}
 }
-- 
1.6.0.6