enhance support for pointer arithmetic

2008-03-30  Juerg Billeter  <j@bitron.ch>

	* vala/valasemanticanalyzer.vala: enhance support for pointer
	  arithmetic

svn path=/trunk/; revision=1163

diff --git a/ChangeLog b/ChangeLog
index b204817..684155e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-03-30  Jürg Billeter  <j@bitron.ch>
+
+       * vala/valasemanticanalyzer.vala: enhance support for pointer
+         arithmetic
+
 2008-03-29  Jürg Billeter  <j@bitron.ch>
 
        * vala/parser.y, vala/valaclass.vala, vala/valaconstructor.vala,

diff --git a/vala/valasemanticanalyzer.vala b/vala/valasemanticanalyzer.vala
index 8d144d3..4c42914 100644 (file)
--- a/vala/valasemanticanalyzer.vala
+++ b/vala/valasemanticanalyzer.vala
@@ -44,6 +44,7 @@ public class Vala.SemanticAnalyzer : CodeVisitor {
        DataType int_type;
        DataType uint_type;
        DataType ulong_type;
+       DataType size_t_type;
        DataType unichar_type;
        DataType type_type;
        Typesymbol pointer_type;
@@ -86,6 +87,7 @@ public class Vala.SemanticAnalyzer : CodeVisitor {
                int_type = new ValueType ((Typesymbol) root_symbol.scope.lookup ("int"));
                uint_type = new ValueType ((Typesymbol) root_symbol.scope.lookup ("uint"));
                ulong_type = new ValueType ((Typesymbol) root_symbol.scope.lookup ("ulong"));
+               size_t_type = new ValueType ((Typesymbol) root_symbol.scope.lookup ("size_t"));
                unichar_type = new ValueType ((Typesymbol) root_symbol.scope.lookup ("unichar"));
 
                // TODO: don't require GLib namespace in semantic analyzer
@@ -2547,9 +2549,12 @@ public class Vala.SemanticAnalyzer : CodeVisitor {
                                if (offset_type != null && offset_type.is_integer_type ()) {
                                        if (expr.operator == BinaryOperator.PLUS
                                            || expr.operator == BinaryOperator.MINUS) {
-                                               // pointer arithmetic
+                                               // pointer arithmetic: pointer +/- offset
                                                expr.static_type = expr.left.static_type.copy ();
                                        }
+                               } else if (expr.right.static_type is PointerType) {
+                                       // pointer arithmetic: pointer - pointer
+                                       expr.static_type = size_t_type;
                                }
                        }
 
@@ -2580,6 +2585,8 @@ public class Vala.SemanticAnalyzer : CodeVisitor {
                        if (expr.left.static_type.compatible (string_type)
                            && expr.right.static_type.compatible (string_type)) {
                                // string comparison
+                               } else if (expr.left.static_type is PointerType && expr.right.static_type is PointerType) {
+                                       // pointer arithmetic
                        } else {
                                var resulting_type = get_arithmetic_result_type (expr.left.static_type, expr.right.static_type);