add support for missing arguments to binary op

at least for strings, octets, and numerical types

That way we don't need to do

	&foo = &bar - (&baz || 0)

and we can instead just do

	&foo = &bar - &baz

diff --git a/src/lib/unlang/xlat_expr.c b/src/lib/unlang/xlat_expr.c
index 0eb4012dcb9385f89301f7a9e4357f24ce1108e3..1c6305ae032302e29740fe1114a957fd32e71022 100644 (file)
--- a/src/lib/unlang/xlat_expr.c
+++ b/src/lib/unlang/xlat_expr.c
@@ -349,8 +349,8 @@ flags:
 }
 
 static xlat_arg_parser_t const binary_op_xlat_args[] = {
-       { .required = true, .type = FR_TYPE_VOID },
-       { .required = true, .type = FR_TYPE_VOID },
+       { .required = false, .type = FR_TYPE_VOID },
+       { .required = false, .type = FR_TYPE_VOID },
        XLAT_ARG_PARSER_TERMINATOR
 };
 
@@ -371,35 +371,55 @@ static xlat_action_t xlat_binary_op(TALLOC_CTX *ctx, fr_dcursor_t *out,
        a = fr_value_box_list_head(in);
        b = fr_value_box_list_next(in, a);
 
-#ifdef STATIC_ANALYZER
-       if (!a || !b) return XLAT_ACTION_FAIL;
-#else
-       fr_assert(a != NULL);
-       fr_assert(b != NULL);
-#endif
+       if (!a && !b) return XLAT_ACTION_FAIL;
 
-       fr_assert(a->type == FR_TYPE_GROUP);
-       fr_assert(b->type == FR_TYPE_GROUP);
+       fr_assert(!a || (a->type == FR_TYPE_GROUP));
+       fr_assert(!b || (b->type == FR_TYPE_GROUP));
 
        if (fr_comparison_op[op]) {
+               if (!a || !b) return XLAT_ACTION_FAIL;
+
                rcode = fr_value_calc_list_cmp(dst, dst, &a->vb_group, op, &b->vb_group);
        } else {
-               if (fr_value_box_list_num_elements(&a->vb_group) != 1) {
+               fr_value_box_t one, two;
+
+               if (fr_value_box_list_num_elements(&a->vb_group) > 1) {
                        REDEBUG("Expected one value as the first argument, got %d",
                                fr_value_box_list_num_elements(&a->vb_group));
                        return XLAT_ACTION_FAIL;
                }
+               a = fr_value_box_list_head(&a->vb_group);
 
-               if (fr_value_box_list_num_elements(&b->vb_group) != 1) {
+               if (fr_value_box_list_num_elements(&b->vb_group) > 1) {
                        REDEBUG("Expected one value as the second argument, got %d",
                                fr_value_box_list_num_elements(&b->vb_group));
                        return XLAT_ACTION_FAIL;
                }
+               b = fr_value_box_list_head(&b->vb_group);
+
+               if (!a && !b) return XLAT_ACTION_FAIL;
+
+               if (!a) {
+                       if (!fr_type_is_numeric(b->type) && (b->type != FR_TYPE_STRING) && (b->type != FR_TYPE_OCTETS)) {
+                               REDEBUG("First argument is missing");
+                               return XLAT_ACTION_FAIL;
+                       }
+
+                       a = &one;
+                       fr_value_box_init(a, b->type, NULL, false);
+               }
+
+               if (!b) {
+                       if (!fr_type_is_numeric(a->type) && (a->type != FR_TYPE_STRING) && (a->type != FR_TYPE_OCTETS)) {
+                               REDEBUG("Second argument is missing");
+                               return XLAT_ACTION_FAIL;
+                       }
+
+                       b = &two;
+                       fr_value_box_init(b, a->type, NULL, false);
+               }
 
-               rcode = fr_value_calc_binary_op(dst, dst, default_type,
-                                               fr_value_box_list_head(&a->vb_group),
-                                               op,
-                                               fr_value_box_list_head(&b->vb_group));
+               rcode = fr_value_calc_binary_op(dst, dst, default_type, a, op, b);
        }
        if (rcode < 0) {
                RPEDEBUG("Failed calculating result, returning NULL");

diff --git a/src/tests/keywords/expr-missing b/src/tests/keywords/expr-missing
new file mode 100644 (file)
index 0000000..b40dbb4
--- /dev/null
+++ b/src/tests/keywords/expr-missing
@@ -0,0 +1,28 @@
+uint32 a
+uint32 b
+uint32 c
+
+string sa
+string sb
+string sc
+
+#
+#  b is missing, so its default value is 0
+#
+&a = 1
+&c = &a - &b
+
+if !(&c == &a) {
+       test_fail
+}
+
+&sa = "foo"
+&sc = &sa + &sb
+
+#
+#  sb is missing, so its default value is the empty string
+#
+if !(&sc == &sa) {
+       test_fail
+}
+success