From: Simon Werbeck <simon.werbeck@gmail.com>
Date: Wed, 26 Nov 2014 11:24:31 +0000 (+0100)
Subject: Warn when using 'this' before chain up
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3a40f6f1e7d472c1345003d4d1bbfaba6165c6f8;p=thirdparty%2Fvala.git

Warn when using 'this' before chain up

Do flow analysis on 'this' parameter in creation methods. Report a
warning if it is used before a chain up call.

https://bugzilla.gnome.org/show_bug.cgi?id=567269
---

diff --git a/vala/valaflowanalyzer.vala b/vala/valaflowanalyzer.vala
index e073c4c21..d2de29ca3 100644
--- a/vala/valaflowanalyzer.vala
+++ b/vala/valaflowanalyzer.vala
@@ -429,7 +429,11 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 							Report.error (used_var.source_reference, "use of possibly unassigned local variable `%s'".printf (used_var.name));
 						} else {
 							// parameter
-							Report.warning (used_var.source_reference, "use of possibly unassigned parameter `%s'".printf (used_var.name));
+							if (used_var.name == "this") {
+								Report.warning (used_var.source_reference, "possible reference to `this' before chaining up");
+							} else {
+								Report.warning (used_var.source_reference, "use of possibly unassigned parameter `%s'".printf (used_var.name));
+							}
 						}
 						continue;
 					}
@@ -461,7 +465,11 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 						Report.error (node.source_reference, "use of possibly unassigned local variable `%s'".printf (var_symbol.name));
 					} else {
 						// parameter
-						Report.warning (node.source_reference, "use of possibly unassigned parameter `%s'".printf (var_symbol.name));
+						if (var_symbol.name == "this") {
+							Report.warning (node.source_reference, "possible reference to `this' before chaining up");
+						} else {
+							Report.warning (node.source_reference, "use of possibly unassigned parameter `%s'".printf (var_symbol.name));
+						}
 					}
 					continue;
 				}
diff --git a/vala/valamemberaccess.vala b/vala/valamemberaccess.vala
index 3bc9eb13b..4fac98adc 100644
--- a/vala/valamemberaccess.vala
+++ b/vala/valamemberaccess.vala
@@ -950,7 +950,7 @@ public class Vala.MemberAccess : Expression {
 		var param = symbol_reference as Parameter;
 		if (local != null) {
 			collection.add (local);
-		} else if (param != null && param.direction == ParameterDirection.OUT) {
+		} else if (param != null && (param.direction == ParameterDirection.OUT || (param.name == "this" && param.parent_symbol is CreationMethod && ((CreationMethod) param.parent_symbol).chain_up))) {
 			collection.add (param);
 		}
 	}
diff --git a/vala/valamethodcall.vala b/vala/valamethodcall.vala
index 2b43ec842..5c17ef098 100644
--- a/vala/valamethodcall.vala
+++ b/vala/valamethodcall.vala
@@ -287,6 +287,7 @@ public class Vala.MethodCall : Expression {
 
 			var struct_creation_expression = new ObjectCreationExpression ((MemberAccess) call, source_reference);
 			struct_creation_expression.struct_creation = true;
+			struct_creation_expression.struct_chainup = is_chainup;
 			foreach (Expression arg in get_argument_list ()) {
 				struct_creation_expression.add_argument (arg);
 			}
@@ -677,7 +678,19 @@ public class Vala.MethodCall : Expression {
 	}
 
 	public override void get_defined_variables (Collection<Variable> collection) {
-		call.get_defined_variables (collection);
+		if (is_chainup) {
+			var this_parameter = call.symbol_reference as Parameter;
+			if (this_parameter == null) {
+				Symbol sym = (Block) parent_statement.parent_node;
+				do {
+					sym = sym.parent_symbol;
+				} while (sym is Block);
+				this_parameter = ((Method) sym).this_parameter;
+			}
+			collection.add (this_parameter);
+		} else {
+			call.get_defined_variables (collection);
+		}
 
 		foreach (Expression arg in argument_list) {
 			arg.get_defined_variables (collection);
@@ -685,7 +698,9 @@ public class Vala.MethodCall : Expression {
 	}
 
 	public override void get_used_variables (Collection<Variable> collection) {
-		call.get_used_variables (collection);
+		if (!is_chainup) {
+			call.get_used_variables (collection);
+		}
 
 		foreach (Expression arg in argument_list) {
 			arg.get_used_variables (collection);
diff --git a/vala/valaobjectcreationexpression.vala b/vala/valaobjectcreationexpression.vala
index 7a2d6fbf8..a920673b0 100644
--- a/vala/valaobjectcreationexpression.vala
+++ b/vala/valaobjectcreationexpression.vala
@@ -46,6 +46,7 @@ public class Vala.ObjectCreationExpression : Expression {
 	public bool is_yield_expression { get; set; }
 
 	public bool struct_creation { get; set; }
+	public bool struct_chainup { get; set; }
 
 	private List<Expression> argument_list = new ArrayList<Expression> ();
 
@@ -535,6 +536,18 @@ public class Vala.ObjectCreationExpression : Expression {
 	}
 
 	public override void get_defined_variables (Collection<Variable> collection) {
+		if (struct_chainup) {
+			var this_parameter = member_name.inner.symbol_reference as Parameter;
+			if (this_parameter == null) {
+				Symbol sym = (Block) parent_statement.parent_node;
+				do {
+					sym = sym.parent_symbol;
+				} while (sym is Block);
+				this_parameter = ((Method) sym).this_parameter;
+			}
+			collection.add (this_parameter);
+		}
+
 		foreach (Expression arg in argument_list) {
 			arg.get_defined_variables (collection);
 		}