[vala] Use strict non-null types with --enable-experimental-non-null

[Jürg Billeter <juergbi src gnome org>]

commit 80c18a1d1ff357be7f1d0f50f1aa331f206a0a0a
Author: Jürg Billeter <j bitron ch>
Date:   Sun Oct 18 16:04:08 2009 +0200

    Use strict non-null types with --enable-experimental-non-null
    
    Do not consider local variables nullable or nullable types compatible
    to non-null types when using --enable-experimental-non-null.

 compiler/valacompiler.vala   |   15 +--
 vala/Makefile.am             |    1 -
 vala/valacodecontext.vala    |    2 +-
 vala/valadatatype.vala       |    4 +
 vala/valanullchecker.vala    |  241 ------------------------------------------
 vala/valanulltype.vala       |   11 ++-
 vala/valasymbolresolver.vala |   18 ++-
 vapi/glib-2.0.vapi           |    8 +-
 8 files changed, 36 insertions(+), 264 deletions(-)
---
diff --git a/compiler/valacompiler.vala b/compiler/valacompiler.vala
index f2b0234..b7e5350 100644
--- a/compiler/valacompiler.vala
+++ b/compiler/valacompiler.vala
@@ -55,7 +55,7 @@ class Vala.Compiler {
 	static bool enable_checking;
 	static bool deprecated;
 	static bool experimental;
-	static bool non_null_experimental;
+	static bool experimental_non_null;
 	static bool disable_dbus_transformation;
 	static bool disable_warnings;
 	static string cc_command;
@@ -101,7 +101,7 @@ class Vala.Compiler {
 		{ "enable-deprecated", 0, 0, OptionArg.NONE, ref deprecated, "Enable deprecated features", null },
 		{ "enable-experimental", 0, 0, OptionArg.NONE, ref experimental, "Enable experimental features", null },
 		{ "disable-warnings", 0, 0, OptionArg.NONE, ref disable_warnings, "Disable warnings", null },
-		{ "enable-non-null-experimental", 0, 0, OptionArg.NONE, ref non_null_experimental, "Enable experimental enhancements for non-null types", null },
+		{ "enable-experimental-non-null", 0, 0, OptionArg.NONE, ref experimental_non_null, "Enable experimental enhancements for non-null types", null },
 		{ "disable-dbus-transformation", 0, 0, OptionArg.NONE, ref disable_dbus_transformation, "Disable transformation of D-Bus member names", null },
 		{ "cc", 0, 0, OptionArg.STRING, ref cc_command, "Use COMMAND as C compiler command", "COMMAND" },
 		{ "Xcc", 'X', 0, OptionArg.STRING_ARRAY, ref cc_options, "Pass OPTION to the C compiler", "OPTION..." },
@@ -188,7 +188,7 @@ class Vala.Compiler {
 		context.checking = enable_checking;
 		context.deprecated = deprecated;
 		context.experimental = experimental;
-		context.non_null_experimental = non_null_experimental;
+		context.experimental_non_null = experimental || experimental_non_null;
 		context.dbus_transformation = !disable_dbus_transformation;
 		context.report.enable_warnings = !disable_warnings;
 		context.report.set_verbose_errors (!quiet_mode);
@@ -355,15 +355,6 @@ class Vala.Compiler {
 			return quit ();
 		}
 
-		if (context.non_null_experimental) {
-			var null_checker = new NullChecker ();
-			null_checker.check (context);
-
-			if (context.report.get_errors () > 0) {
-				return quit ();
-			}
-		}
-
 		context.codegen.emit (context);
 		
 		if (context.report.get_errors () > 0) {
diff --git a/vala/Makefile.am b/vala/Makefile.am
index db4d5c2..3955061 100644
--- a/vala/Makefile.am
+++ b/vala/Makefile.am
@@ -98,7 +98,6 @@ libvalacore_la_VALASOURCES = \
 	valamethodcall.vala \
 	valamethodtype.vala \
 	valanamespace.vala \
-	valanullchecker.vala \
 	valanullliteral.vala \
 	valanulltype.vala \
 	valaobjectcreationexpression.vala \
diff --git a/vala/valacodecontext.vala b/vala/valacodecontext.vala
index 938e511..b079d9f 100644
--- a/vala/valacodecontext.vala
+++ b/vala/valacodecontext.vala
@@ -49,7 +49,7 @@ public class Vala.CodeContext {
 	/**
 	 * Enable experimental enhancements for non-null types.
 	 */
-	public bool non_null_experimental { get; set; }
+	public bool experimental_non_null { get; set; }
 
 	/**
 	 * Enable transformation of D-Bus member names in dynamic client support.
diff --git a/vala/valadatatype.vala b/vala/valadatatype.vala
index b792ef1..b8b6ceb 100644
--- a/vala/valadatatype.vala
+++ b/vala/valadatatype.vala
@@ -297,6 +297,10 @@ public abstract class Vala.DataType : CodeNode {
 	}
 
 	public virtual bool compatible (DataType target_type) {
+		if (CodeContext.get ().experimental_non_null && nullable && !target_type.nullable) {
+			return false;
+		}
+
 		if (target_type.get_type_id () == "G_TYPE_VALUE" && get_type_id () != null) {
 			// allow implicit conversion to GValue
 			return true;
diff --git a/vala/valanulltype.vala b/vala/valanulltype.vala
index f58cce3..cbe0419 100644
--- a/vala/valanulltype.vala
+++ b/vala/valanulltype.vala
@@ -1,6 +1,6 @@
 /* valanulltype.vala
  *
- * Copyright (C) 2007-2008  Jürg Billeter
+ * Copyright (C) 2007-2009  Jürg Billeter
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -27,10 +27,15 @@ using GLib;
  */
 public class Vala.NullType : ReferenceType {
 	public NullType (SourceReference source_reference) {
+		this.nullable = true;
 		this.source_reference = source_reference;
 	}
 
 	public override bool compatible (DataType target_type) {
+		if (CodeContext.get ().experimental_non_null) {
+			return target_type.nullable;
+		}
+
 		if (!(target_type is PointerType) && (target_type is NullType || (target_type.data_type == null && target_type.type_parameter == null))) {
 			return true;
 		}
@@ -64,4 +69,8 @@ public class Vala.NullType : ReferenceType {
 	public override bool is_disposable () {
 		return false;
 	}
+
+	public override string to_qualified_string (Scope? scope = null) {
+		return "null";
+	}
 }
diff --git a/vala/valasymbolresolver.vala b/vala/valasymbolresolver.vala
index 39fa9b9..de31696 100644
--- a/vala/valasymbolresolver.vala
+++ b/vala/valasymbolresolver.vala
@@ -28,6 +28,7 @@ using GLib;
  * Code visitor resolving symbol names.
  */
 public class Vala.SymbolResolver : CodeVisitor {
+	CodeContext context;
 	Symbol root_symbol;
 	Scope current_scope;
 	
@@ -37,6 +38,7 @@ public class Vala.SymbolResolver : CodeVisitor {
 	 * @param context a code context
 	 */
 	public void resolve (CodeContext context) {
+		this.context = context;
 		root_symbol = context.root;
 
 		context.root.accept (this);
@@ -348,12 +350,16 @@ public class Vala.SymbolResolver : CodeVisitor {
 
 	public override void visit_local_variable (LocalVariable local) {
 		local.accept_children (this);
-		if (local.variable_type is ReferenceType) {
-			var array_type = local.variable_type as ArrayType;
-			if (array_type != null && array_type.fixed_length) {
-				// local fixed length arrays are not nullable
-			} else {
-				local.variable_type.nullable = true;
+		if (!context.experimental_non_null) {
+			// local reference variables are considered nullable
+			// except when using experimental non-null enhancements
+			if (local.variable_type is ReferenceType) {
+				var array_type = local.variable_type as ArrayType;
+				if (array_type != null && array_type.fixed_length) {
+					// local fixed length arrays are not nullable
+				} else {
+					local.variable_type.nullable = true;
+				}
 			}
 		}
 	}
diff --git a/vapi/glib-2.0.vapi b/vapi/glib-2.0.vapi
index 2d31384..d16c2ec 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -2484,7 +2484,7 @@ namespace GLib {
 
 		public string? read_line () {
 			int c;
-			StringBuilder ret = null;
+			StringBuilder? ret = null;
 			while ((c = getc ()) != EOF) {
 				if (ret == null) {
 					ret = new StringBuilder ();
@@ -2494,7 +2494,11 @@ namespace GLib {
 				}
 				ret.append_c ((char) c);
 			}
-			return ret == null ? null : ret.str;
+			if (ret == null) {
+				return null;
+			} else {
+				return ret.str;
+			}
 		}
 	}