[vala/wip/transform: 84/98] Return (owned) for temp variables when possible to avoid useless copies

[Luca Bruno <lucabru src gnome org>]

commit c40f5a6f2bed524ba9ed5c717736366675b8a571
Author: Luca Bruno <lucabru src gnome org>
Date:   Sat Feb 1 11:10:52 2014 +0100

    Return (owned) for temp variables when possible to avoid useless copies

 codegen/valaccodetransformer.vala |   14 ++++++--------
 vala/valacodebuilder.vala         |    3 +--
 vala/valacodetransformer.vala     |   17 +++++++++++++++++
 vala/valasemanticanalyzer.vala    |   16 ----------------
 4 files changed, 24 insertions(+), 26 deletions(-)
---
diff --git a/codegen/valaccodetransformer.vala b/codegen/valaccodetransformer.vala
index 0f286fc..3b158e1 100644
--- a/codegen/valaccodetransformer.vala
+++ b/codegen/valaccodetransformer.vala
@@ -377,11 +377,9 @@ public class Vala.CCodeTransformer : CodeTransformer {
                                var target_type = copy_type (expr.target_type);
                                push_builder (new CodeBuilder (context, expr.parent_statement, 
expr.source_reference));
 
-                               // FIXME: use create_temp_access behavior
-                               var replacement = expression (b.add_temp_declaration (copy_type 
(expr.value_type), expr, true));
+                               var local = b.add_temp_declaration (copy_type (expr.value_type), expr);
+                               var replacement = return_temp_access (local, expr.value_type, target_type, 
formal_target_type);
 
-                               replacement.target_type = copy_type (target_type);
-                               replacement.formal_target_type = copy_type (formal_target_type);
                                context.analyzer.replaced_nodes.add (expr);
                                old_parent_node.replace_expression (expr, replacement);
                                b.check (this);
@@ -514,13 +512,13 @@ public class Vala.CCodeTransformer : CodeTransformer {
                                Report.error (expr.source_reference, "Field initializers must not throw 
errors");
                        } else {
                                var old_parent_node = expr.parent_node;
-                               var target_type = expr.target_type != null ? expr.target_type.copy () : null;
+                               var target_type = copy_type (expr.target_type);
+                               var formal_target_type = copy_type (expr.formal_target_type);
                                push_builder (new CodeBuilder (context, expr.parent_statement, 
expr.source_reference));
 
-                               // FIXME: use create_temp_access behavior
-                               var replacement = expression (b.add_temp_declaration (expr.value_type, expr, 
true));
+                               var local = b.add_temp_declaration (expr.value_type, expr);
+                               var replacement = return_temp_access (local, expr.value_type, target_type, 
formal_target_type);
 
-                               replacement.target_type = target_type;
                                context.analyzer.replaced_nodes.add (expr);
                                old_parent_node.replace_expression (expr, replacement);
                                b.check (this);
diff --git a/vala/valacodebuilder.vala b/vala/valacodebuilder.vala
index 2d5e364..1c2c03e 100644
--- a/vala/valacodebuilder.vala
+++ b/vala/valacodebuilder.vala
@@ -247,9 +247,8 @@ public class Vala.CodeBuilder {
                add_statement (new ContinueStatement (source_reference));
        }
 
-       public string add_temp_declaration (DataType? type, Expression? initializer = null, bool floating = 
false) {
+       public string add_temp_declaration (DataType? type, Expression? initializer = null) {
                var local = new LocalVariable (type, CodeNode.get_temp_name (), initializer, 
source_reference);
-               // FIXME: use create_temp_access behavior
                var stmt = new DeclarationStatement (local, source_reference);
                insert_block.insert_before (insert_statement, stmt);
                decl_nodes.add (stmt);
diff --git a/vala/valacodetransformer.vala b/vala/valacodetransformer.vala
index 551df45..cffeb99 100644
--- a/vala/valacodetransformer.vala
+++ b/vala/valacodetransformer.vala
@@ -77,6 +77,23 @@ public class Vala.CodeTransformer : CodeVisitor {
                return ret;
        }
 
+       // Create an access to a temporary variable, with proper reference transfer if needed to avoid 
unnecessary copies
+       public Expression return_temp_access (string local, DataType value_type, DataType? target_type, 
DataType? formal_target_type = null) {
+               Expression temp_access = new MemberAccess.simple (local, b.source_reference);
+
+               var target_owned = target_type == null || target_type.value_owned;
+               if (target_owned && value_type.is_disposable ()) {
+                       temp_access = new ReferenceTransferExpression (temp_access, b.source_reference);
+                       temp_access.target_type = target_type != null ? target_type.copy () : value_type.copy 
();
+                       temp_access.target_type.value_owned = true;
+                       temp_access.formal_target_type = copy_type (formal_target_type);
+               } else {
+                       temp_access.target_type = copy_type (target_type);
+               }
+               
+               return temp_access;
+       }
+
        public bool get_cached_wrapper (string key, out CodeNode node) {
                node = wrapper_cache.get (key);
                return node != null;
diff --git a/vala/valasemanticanalyzer.vala b/vala/valasemanticanalyzer.vala
index 1f6e751..4dac0ac 100644
--- a/vala/valasemanticanalyzer.vala
+++ b/vala/valasemanticanalyzer.vala
@@ -777,22 +777,6 @@ public class Vala.SemanticAnalyzer : CodeVisitor {
 
                return false;
        }
-
-       // Create an access to a temporary variable, with proper reference transfer if needed
-       public static Expression create_temp_access (LocalVariable local, DataType? target_type) {
-               Expression temp_access = new MemberAccess.simple (local.name, local.source_reference);
-
-               var target_owned = target_type == null || target_type.value_owned;
-               if (target_owned && local.variable_type.is_disposable ()) {
-                       temp_access = new ReferenceTransferExpression (temp_access, local.source_reference);
-                       temp_access.target_type = target_type != null ? target_type.copy () : 
local.variable_type.copy ();
-                       temp_access.target_type.value_owned = true;
-               } else {
-                       temp_access.target_type = target_type != null ? target_type.copy () : null;
-               }
-               
-               return temp_access;
-       }
        
        public void visit_member_initializer (MemberInitializer init, DataType type) {
                init.symbol_reference = symbol_lookup_inherited (type.data_type, init.name);