Use result variable in C for method results

This eliminates the long C return statements and will help when
adding support for postconditions in normal methods.

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 36e2b2cd9ed244db51bdd7e04e6931052ee07b5a..9ce9d084008b96fa775125e02b783323f2dd70d2 100644 (file)
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -1335,6 +1335,12 @@ internal class Vala.CCodeBaseModule : CCodeModule {
                                function.block.prepend_statement (cdecl);
                        }
 
+                       if (acc.readable) {
+                               var cdecl = new CCodeDeclaration (acc.value_type.get_cname ());
+                               cdecl.add_declarator (new CCodeVariableDeclarator ("result"));
+                               function.block.prepend_statement (cdecl);
+                       }
+
                        if (current_method_inner_error) {
                                var cdecl = new CCodeDeclaration ("GError *");
                                cdecl.add_declarator (new CCodeVariableDeclarator ("_inner_error_", new CCodeConstant ("NULL")));
@@ -2212,7 +2218,7 @@ internal class Vala.CCodeBaseModule : CCodeModule {
                stmt.ccodenode = cfrag;
        }
 
-       public void append_local_free (Symbol sym, CCodeFragment cfrag, bool stop_at_loop) {
+       public void append_local_free (Symbol sym, CCodeFragment cfrag, bool stop_at_loop = false) {
                var b = (Block) sym;
 
                var local_vars = b.get_local_variables ();
@@ -2281,7 +2287,7 @@ internal class Vala.CCodeBaseModule : CCodeModule {
                stmt.ccodenode = cfrag;
        }
 
-       private bool append_local_free_expr (Symbol sym, CCodeCommaExpression ccomma, bool stop_at_loop) {
+       private bool append_local_free_expr (Symbol sym, CCodeCommaExpression ccomma, bool stop_at_loop = false) {
                bool found = false;
        
                var b = (Block) sym;
@@ -2320,28 +2326,6 @@ internal class Vala.CCodeBaseModule : CCodeModule {
                return found;
        }
 
-       private void create_local_free_expr (Expression expr) {
-               var expr_type = expr.value_type;
-               if (expr.target_type != null) {
-                       expr_type = expr.target_type;
-               }
-
-               var return_expr_decl = get_temp_variable (expr_type, true, expr);
-               
-               var ccomma = new CCodeCommaExpression ();
-               ccomma.append_expression (new CCodeAssignment (get_variable_cexpression (return_expr_decl.name), (CCodeExpression) expr.ccodenode));
-
-               if (!append_local_free_expr (current_symbol, ccomma, false)) {
-                       /* no local variables need to be freed */
-                       return;
-               }
-
-               ccomma.append_expression (get_variable_cexpression (return_expr_decl.name));
-               
-               expr.ccodenode = ccomma;
-               expr.temp_vars.add (return_expr_decl);
-       }
-
        public override void visit_return_statement (ReturnStatement stmt) {
                // avoid unnecessary ref/unref pair
                if (stmt.return_expression != null) {
@@ -2398,7 +2382,13 @@ internal class Vala.CCodeBaseModule : CCodeModule {
                                stmt.return_expression.temp_vars.add (return_expr_decl);
                        }
 
-                       create_local_free_expr (stmt.return_expression);
+                       var cfrag = new CCodeFragment ();
+
+                       // assign method result to `result'
+                       cfrag.append (new CCodeExpressionStatement (new CCodeAssignment (new CCodeIdentifier ("result"), (CCodeExpression) stmt.return_expression.ccodenode)));
+
+                       // free local variables
+                       append_local_free (current_symbol, cfrag);
 
                        // Property getters of non simple structs shall return the struct value as out parameter,
                        // therefore replace any return statement with an assignment statement to the out formal
@@ -2406,14 +2396,14 @@ internal class Vala.CCodeBaseModule : CCodeModule {
                        if (current_property_accessor != null &&
                            current_property_accessor.readable &&
                            current_property_accessor.prop.property_type.is_real_struct_type()) {
-                               var cfragment = new CCodeFragment ();
-                               cfragment.append (new CCodeExpressionStatement (new CCodeAssignment (new CCodeIdentifier ("*value"), (CCodeExpression) stmt.return_expression.ccodenode)));
-                               cfragment.append (new CCodeReturnStatement ());
-                               stmt.ccodenode = cfragment;
+                               cfrag.append (new CCodeExpressionStatement (new CCodeAssignment (new CCodeIdentifier ("*value"), new CCodeIdentifier ("result"))));
+                               cfrag.append (new CCodeReturnStatement ());
                        } else {
-                               stmt.ccodenode = new CCodeReturnStatement ((CCodeExpression) stmt.return_expression.ccodenode);
+                               cfrag.append (new CCodeReturnStatement (new CCodeIdentifier ("result")));
                        }
 
+                       stmt.ccodenode = cfrag;
+
                        create_temp_decl (stmt, stmt.return_expression.temp_vars);
 
                        if (return_expression_symbol != null) {

diff --git a/codegen/valaccodemethodmodule.vala b/codegen/valaccodemethodmodule.vala
index e1e3de1af189561b4d6e0f127798bea8768cb17e..ecf15196740b5269c4c57946e1ec50a4ba97c5f1 100644 (file)
--- a/codegen/valaccodemethodmodule.vala
+++ b/codegen/valaccodemethodmodule.vala
@@ -431,6 +431,12 @@ internal class Vala.CCodeMethodModule : CCodeStructModule {
                                        }
                                }
 
+                               if (!(m.return_type is VoidType)) {
+                                       var cdecl = new CCodeDeclaration (m.return_type.get_cname ());
+                                       cdecl.add_declarator (new CCodeVariableDeclarator ("result"));
+                                       cinit.append (cdecl);
+                               }
+
                                if (inner_error) {
                                        /* always separate error parameter and inner_error local variable
                                         * as error may be set to NULL but we're always interested in inner errors