[vala/wip/transform] Make Method.yield_count be stateless

[Luca Bruno <lucabru src gnome org>]

commit cc8e157820babed625b311178fb9f48e3e818dc0
Author: Luca Bruno <lucabru src gnome org>
Date:   Sat Oct 27 18:32:59 2012 +0200

    Make Method.yield_count be stateless

 codegen/valaccodemethodmodule.vala     |   28 +++++++++++++++++++++++++++-
 vala/valamethod.vala                   |    2 --
 vala/valamethodcall.vala               |    1 -
 vala/valaobjectcreationexpression.vala |    1 -
 vala/valayieldstatement.vala           |    2 --
 5 files changed, 27 insertions(+), 7 deletions(-)
---
diff --git a/codegen/valaccodemethodmodule.vala b/codegen/valaccodemethodmodule.vala
index 238db83..1667978 100644
--- a/codegen/valaccodemethodmodule.vala
+++ b/codegen/valaccodemethodmodule.vala
@@ -283,6 +283,30 @@ public abstract class Vala.CCodeMethodModule : CCodeStructModule {
 		ccode.add_expression (register_call);
 	}
 
+	int get_yield_count (Method m) {
+		int yield_count = 0;
+		var traverse = new TraverseVisitor ((n) => {
+				if (n is Method && n != m) {
+					return TraverseStatus.STOP;
+				} else if (n is MethodCall) {
+					var expr = (MethodCall) n;
+					if (expr.is_yield_expression) {
+						yield_count++;
+					}
+				} else if (n is YieldStatement) {
+					yield_count++;
+				} else if (n is ObjectCreationExpression) {
+					var expr = (ObjectCreationExpression) n;
+					if (expr.is_yield_expression) {
+						yield_count++;
+					}
+				}
+				return TraverseStatus.CONTINUE;
+			});
+		m.accept (traverse);
+		return yield_count;
+	}
+
 	/**
 	 * This function generates the code the given method. If the method is
 	 * a constructor, _construct is generated, unless it's variadic, in which
@@ -463,7 +487,9 @@ public abstract class Vala.CCodeMethodModule : CCodeStructModule {
 					ccode.add_case (new CCodeConstant ("0"));
 					ccode.add_goto ("_state_0");
 
-					for (int state = 1; state <= m.yield_count; state++) {
+					var yield_count = get_yield_count (m);
+
+					for (int state = 1; state <= yield_count; state++) {
 						ccode.add_case (new CCodeConstant (state.to_string ()));
 						ccode.add_goto ("_state_%d".printf (state));
 					}
diff --git a/vala/valamethod.vala b/vala/valamethod.vala
index 8713b9c..6a47542 100644
--- a/vala/valamethod.vala
+++ b/vala/valamethod.vala
@@ -172,8 +172,6 @@ public class Vala.Method : Subroutine {
 
 	public bool is_async_callback { get; set; }
 
-	public int yield_count { get; set; }
-
 	private List<Parameter> parameters = new ArrayList<Parameter> ();
 	private List<Expression> preconditions;
 	private List<Expression> postconditions;
diff --git a/vala/valamethodcall.vala b/vala/valamethodcall.vala
index 32e346f..b9d78b6 100644
--- a/vala/valamethodcall.vala
+++ b/vala/valamethodcall.vala
@@ -608,7 +608,6 @@ public class Vala.MethodCall : Expression {
 					error = true;
 					Report.error (source_reference, "yield expression not available outside async method");
 				}
-				current_method.yield_count++;
 			}
 			if (m.returns_floating_reference) {
 				value_type.floating_reference = true;
diff --git a/vala/valaobjectcreationexpression.vala b/vala/valaobjectcreationexpression.vala
index fbe870b..0efee81 100644
--- a/vala/valaobjectcreationexpression.vala
+++ b/vala/valaobjectcreationexpression.vala
@@ -342,7 +342,6 @@ public class Vala.ObjectCreationExpression : Expression {
 					error = true;
 					Report.error (source_reference, "yield expression not available outside async method");
 				}
-				current_method.yield_count++;
 			}
 
 			var args = get_argument_list ();
diff --git a/vala/valayieldstatement.vala b/vala/valayieldstatement.vala
index 18b49de..718f366 100644
--- a/vala/valayieldstatement.vala
+++ b/vala/valayieldstatement.vala
@@ -75,8 +75,6 @@ public class Vala.YieldStatement : BaseStatement {
 			error = yield_expression.error;
 		}
 
-		context.analyzer.get_current_method (this).yield_count++;
-
 		return !error;
 	}