[vala/staging] codegen: Improve GValueModule.visit_cast_expression()

[Rico Tzschichholz <ricotz src gnome org>]

commit 87dd44b89e8330412ad349fdd4e97a8db71e59ff
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Fri Nov 13 17:15:37 2020 +0100

    codegen: Improve GValueModule.visit_cast_expression()
    
    Re-use the result of the GValue-getter invocation

 codegen/valagvaluemodule.vala | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)
---
diff --git a/codegen/valagvaluemodule.vala b/codegen/valagvaluemodule.vala
index a6109fd40..0429085e6 100644
--- a/codegen/valagvaluemodule.vala
+++ b/codegen/valagvaluemodule.vala
@@ -44,29 +44,41 @@ public class Vala.GValueModule : GAsyncModule {
                }
                ccall.add_argument (gvalue);
 
-               CCodeExpression rv = ccall;
+               CCodeExpression rv;
+               if (target_type is ArrayType) {
+                       var temp_var = get_temp_variable (target_type, true, expr, false);
+                       emit_temp_var (temp_var);
+                       var temp_ref = get_variable_cexpression (temp_var.name);
+                       ccode.add_assignment (temp_ref, ccall);
+                       rv = temp_ref;
 
-               if (expr != null && target_type is ArrayType) {
                        // null-terminated string array
                        var len_call = new CCodeFunctionCall (new CCodeIdentifier ("g_strv_length"));
                        len_call.add_argument (rv);
                        append_array_length (expr, len_call);
                } else if (target_type is StructValueType) {
-                       CodeNode node = expr != null ? (CodeNode) expr : target_type;
-                       var temp_value = create_temp_value (target_type, true, node, true);
+                       var temp_var = get_temp_variable (new PointerType (target_type), true, expr, false);
+                       emit_temp_var (temp_var);
+                       var temp_ref = get_variable_cexpression (temp_var.name);
+                       ccode.add_assignment (temp_ref, ccall);
+                       rv = temp_ref;
+
+                       // default value to fallback to
+                       var temp_value = create_temp_value (target_type, true, expr, true);
                        var ctemp = get_cvalue_ (temp_value);
 
-                       rv = new CCodeUnaryExpression (CCodeUnaryOperator.POINTER_INDIRECTION, new 
CCodeCastExpression (rv, get_ccode_name (new PointerType (target_type))));
                        var holds = new CCodeFunctionCall (new CCodeIdentifier ("G_VALUE_HOLDS"));
                        holds.add_argument (gvalue);
                        holds.add_argument (new CCodeIdentifier (get_ccode_type_id (target_type)));
-                       var cond = new CCodeBinaryExpression (CCodeBinaryOperator.AND, holds, ccall);
+                       var cond = new CCodeBinaryExpression (CCodeBinaryOperator.AND, holds, rv);
                        var warn = new CCodeFunctionCall (new CCodeIdentifier ("g_warning"));
                        warn.add_argument (new CCodeConstant ("\"Invalid GValue unboxing (wrong type or 
NULL)\""));
                        var fail = new CCodeCommaExpression ();
                        fail.append_expression (warn);
                        fail.append_expression (ctemp);
-                       rv = new CCodeConditionalExpression (cond, rv,  fail);
+                       rv = new CCodeConditionalExpression (cond, new CCodeUnaryExpression 
(CCodeUnaryOperator.POINTER_INDIRECTION, rv), fail);
+               } else {
+                       rv = ccall;
                }
 
                set_cvalue (expr, rv);