From: Simon Werbeck <simon.werbeck@gmail.com>
Date: Thu, 27 Nov 2014 14:24:44 +0000 (+0100)
Subject: Allow multiple chain-up calls in the constructor
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7b06c4cc003b75b2e847ba12909cbb64e5e1c13b;p=thirdparty%2Fvala.git

Allow multiple chain-up calls in the constructor

This requires that the instance parameter is initialized at the end of
the constructor.
Another issue is the possibility of initializing 'this' more than once,
so I added a warning when this is the case.

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

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 722547848..718601fc3 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -58,6 +58,7 @@ TESTS = \
 	chainup/base-struct-invalid.test \
 	chainup/class-base.vala \
 	chainup/class-base-foo.vala \
+	chainup/class-multiple.vala \
 	chainup/class-object.vala \
 	chainup/class-this.vala \
 	chainup/class-this-foo.vala \
diff --git a/tests/chainup/class-multiple.vala b/tests/chainup/class-multiple.vala
new file mode 100644
index 000000000..3781f3101
--- /dev/null
+++ b/tests/chainup/class-multiple.vala
@@ -0,0 +1,49 @@
+public class Foo {
+	public bool success;
+
+	Foo.first () {
+		success = true;
+	}
+
+	Foo.second () {
+		assert_not_reached ();
+	}
+
+	public Foo (bool cond) {
+		if (cond) {
+			this.first ();
+		} else {
+			this.second ();
+		}
+	}
+}
+
+public class Bar {
+	public bool success;
+
+	public Bar.first () {
+		success = true;
+	}
+
+	public Bar.second () {
+		assert_not_reached ();
+	}
+}
+
+public class Baz : Bar {
+	public Baz (bool cond) {
+		if (cond) {
+			base.first ();
+		} else {
+			base.second ();
+		}
+	}
+}
+
+void main () {
+	var foo = new Foo (true);
+	assert (foo.success);
+
+	var baz = new Baz (true);
+	assert (baz.success);
+}
diff --git a/vala/valaflowanalyzer.vala b/vala/valaflowanalyzer.vala
index 853eae73d..e073c4c21 100644
--- a/vala/valaflowanalyzer.vala
+++ b/vala/valaflowanalyzer.vala
@@ -207,6 +207,16 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 					m.return_block.add_node (param_ma);
 				}
 			}
+
+			// ensure instance parameter is defined at end of creation method
+			if (m is CreationMethod) {
+				var cm = (CreationMethod) m;
+				if (cm.chain_up) {
+					var this_ma = new MemberAccess.simple ("this");
+					this_ma.symbol_reference = cm.this_parameter;
+					m.return_block.add_node (this_ma);
+				}
+			}
 		}
 
 		current_block = new BasicBlock ();
@@ -435,7 +445,7 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 
 	void check_block_variables (BasicBlock block) {
 		foreach (PhiFunction phi in block.get_phi_functions ()) {
-			Variable versioned_var = process_assignment (var_map, phi.original_variable);
+			Variable versioned_var = process_assignment (var_map, phi.original_variable, phi.original_variable.parent_symbol);
 
 			phi_functions.set (versioned_var, phi);
 		}
@@ -466,7 +476,7 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 			node.get_defined_variables (defined_variables);
 
 			foreach (Variable variable in defined_variables) {
-				process_assignment (var_map, variable);
+				process_assignment (var_map, variable, node);
 			}
 		}
 
@@ -506,7 +516,7 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 		}
 	}
 
-	Variable process_assignment (Map<Symbol, List<Variable>> var_map, Variable var_symbol) {
+	Variable process_assignment (Map<Symbol, List<Variable>> var_map, Variable var_symbol, CodeNode node_reference) {
 		var variable_stack = var_map.get (var_symbol);
 		if (variable_stack == null) {
 			variable_stack = new ArrayList<Variable> ();
@@ -519,6 +529,11 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 		if (var_symbol is LocalVariable) {
 			versioned_var = new LocalVariable (var_symbol.variable_type.copy (), var_symbol.name, null, var_symbol.source_reference);
 		} else {
+			if (var_symbol.name == "this" && var_symbol.parent_symbol is CreationMethod && ((CreationMethod) var_symbol.parent_symbol).chain_up) {
+				if (variable_stack.size > 0) {
+					Report.warning (node_reference.source_reference, "possible reassignment of `this'");
+				}
+			}
 			// parameter
 			versioned_var = new Parameter (var_symbol.name, var_symbol.variable_type.copy (), var_symbol.source_reference);
 		}
diff --git a/vala/valamethodcall.vala b/vala/valamethodcall.vala
index 415191ab6..2b43ec842 100644
--- a/vala/valamethodcall.vala
+++ b/vala/valamethodcall.vala
@@ -238,10 +238,6 @@ public class Vala.MethodCall : Expression {
 				error = true;
 				Report.error (source_reference, "invocation not supported in this context");
 				return false;
-			} else if (cm.chain_up) {
-				error = true;
-				Report.error (source_reference, "Multiple constructor calls in the same constructor are not permitted");
-				return false;
 			}
 			cm.chain_up = true;