new smatch

@@ -62,10 +62,11 @@
         EXPR_INDEX,             // index in initializer
         EXPR_POS,               // position in initializer
         EXPR_FVALUE,
         EXPR_SLICE,
         EXPR_OFFSETOF,
+        EXPR_ASM_OPERAND,
 };
 
 
 /*
  * Flags for tracking the promotion of constness related attributes

@@ -192,11 +193,12 @@
                 // EXPR_SLICE
                 struct /* slice */ {
                         struct expression *base;
                         unsigned r_bitpos, r_nrbits;
                 };
-                // EXPR_CAST and EXPR_SIZEOF
+                // EXPR_CAST, EXPR_FORCE_CAST, EXPR_IMPLIED_CAST,
+                // EXPR_SIZEOF, EXPR_ALIGNOF and EXPR_PTRSIZEOF
                 struct /* cast_arg */ {
                         struct symbol *cast_type;
                         struct expression *cast_expression;
                 };
                 // EXPR_CONDITIONAL

@@ -239,16 +241,36 @@
                         union {
                                 struct ident *ident;
                                 struct expression *index;
                         };
                 };
+                // EXPR_ASM_OPERAND
+                struct {
+                        struct ident *name;
+                        struct expression *constraint;
+                        struct expression *expr;
         };
+        };
 };
 
-/* Constant expression values */
-int is_zero_constant(struct expression *);
+///
+// Constant expression values
+// --------------------------
+
+///
+// test if an expression evaluates to the constant ``0``.
+// @return: ``1`` if @expr evaluate to ``0``,
+//      ``0`` otherwise.
+int is_zero_constant(struct expression *expr);
+
+///
+// test the compile time truth value of an expression
+// @return:
+//      * ``-1`` if @expr is not constant,
+//      * ``0`` or ``1`` depending on the truth value of @expr.
 int expr_truth_value(struct expression *expr);
+
 long long get_expression_value(struct expression *);
 long long const_expression_value(struct expression *);
 long long get_expression_value_silent(struct expression *expr);
 
 /* Expression parsing */