[vala] codegen: Use separate C statements for postfix expressions

[Jürg Billeter <juergbi src gnome org>]

commit a74bc78f3aedc5fd4104b255f82fcddba9d2f287
Author: Jürg Billeter <j bitron ch>
Date:   Tue Dec 21 17:05:56 2010 +0100

    codegen: Use separate C statements for postfix expressions

 codegen/valaccodebasemodule.vala |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)
---
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 1373345..abd7d0e 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -3727,10 +3727,25 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			set_cvalue (expr, get_variable_cexpression (temp_decl.name));
 			return;
 		}
-	
-		var op = expr.increment ? CCodeUnaryOperator.POSTFIX_INCREMENT : CCodeUnaryOperator.POSTFIX_DECREMENT;
-	
-		set_cvalue (expr, new CCodeUnaryExpression (op, get_cvalue (expr.inner)));
+
+		if (expr.parent_node is ExpressionStatement) {
+			var op = expr.increment ? CCodeUnaryOperator.POSTFIX_INCREMENT : CCodeUnaryOperator.POSTFIX_DECREMENT;
+
+			ccode.add_expression (new CCodeUnaryExpression (op, get_cvalue (expr.inner)));
+		} else {
+			// assign current value to temp variable
+			var temp_decl = get_temp_variable (expr.inner.value_type, true, expr, false);
+			emit_temp_var (temp_decl);
+			ccode.add_expression (new CCodeAssignment (get_variable_cexpression (temp_decl.name), get_cvalue (expr.inner)));
+
+			// increment/decrement variable
+			var op = expr.increment ? CCodeBinaryOperator.PLUS : CCodeBinaryOperator.MINUS;
+			var cexpr = new CCodeBinaryExpression (op, get_variable_cexpression (temp_decl.name), new CCodeConstant ("1"));
+			ccode.add_expression (new CCodeAssignment (get_cvalue (expr.inner), cexpr));
+
+			// return previous value
+			set_cvalue (expr, get_variable_cexpression (temp_decl.name));
+		}
 	}
 	
 	private MemberAccess? find_property_access (Expression expr) {