report: make "help" and "?" field implicit

Making "help" and "?" implicit also simplifies code since the
dm_report_init caller (lvm/dmsetup) doesn't need to check on
dm_report_init return whether "help" or "?" was hit while parsing
fields/sort keys in libdevmapper.

The libdevmapper now sets internal "RH_ALREADY_REPORTED" flag
after it reports the "help" or "?" implicit field. Then libdevmapper
itself checks for this flag in dm_report_object and if found,
the actual reporting is skipped (because the "help" implicit field
was reported instead of the actual report).

diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM
index 9e6f92e7ed168d9d425065fa5bc7bb1c56f50e9a..3d1eee158380e11a2497be413c6d63a342826418 100644 (file)
--- a/WHATS_NEW_DM
+++ b/WHATS_NEW_DM
@@ -1,5 +1,6 @@
 Version 1.02.88 - 
 =================================
+  Make "help" and "?" reporting fields implicit.
   Recognize implicit "selected" field if using dm_report_init_with_selection.
   Add support for implicit reporting fields which are predefined in libdm.
   Add DM_REPORT_FIELD_TYPE_PERCENT: separate number and percent fields.

diff --git a/libdm/libdm-report.c b/libdm/libdm-report.c
index 00b99c89c813d409d985249b9a308472f6e8a453..8e46f78a150ee1e992c11af5e34c5c7d00ec3fce 100644 (file)
--- a/libdm/libdm-report.c
+++ b/libdm/libdm-report.c
@@ -24,6 +24,7 @@
  */
 #define RH_SORT_REQUIRED       0x00000100
 #define RH_HEADINGS_PRINTED    0x00000200
+#define RH_ALREADY_REPORTED    0x00000400
 
 struct dm_report {
        struct dm_pool *mem;
@@ -191,29 +192,24 @@ struct row {
 /*
  * Implicit report types and fields.
  */
-static const struct dm_report_object_type _implicit_void_report_types[] = {
-       { 0, "", "", NULL }
-};
-
-static const struct dm_report_field_type _implicit_void_report_fields[] = {
-       { 0, 0, 0, 0, "", "", 0, 0}
-};
-
-static const struct dm_report_object_type *_implicit_report_types = _implicit_void_report_types;
-static const struct dm_report_field_type *_implicit_report_fields = _implicit_void_report_fields;
-
 #define COMMON_REPORT_TYPE 0x80000000
 #define COMMON_FIELD_SELECTED_ID "selected"
+#define COMMON_FIELD_HELP_ID DM_REPORT_FIELD_RESERVED_NAME_HELP
+#define COMMON_FIELD_HELP_ALT_ID DM_REPORT_FIELD_RESERVED_NAME_HELP_ALT
 
-static void *_null_returning_fn(void *obj)
+static void *_null_returning_fn(void *obj __attribute__((unused)))
 {
        return NULL;
 }
 
-static const struct dm_report_object_type _implicit_common_report_types[] = {
-       { COMMON_REPORT_TYPE, "Common", "common_", _null_returning_fn },
-       { 0, "", "", NULL }
-};
+static int _no_report_fn(struct dm_report *rh __attribute__((unused)),
+                        struct dm_pool *mem __attribute__((unused)),
+                        struct dm_report_field *field __attribute__((unused)),
+                        const void *data __attribute__((unused)),
+                        void *private __attribute__((unused)))
+{
+       return 1;
+}
 
 static int _selected_disp(struct dm_report *rh,
                          struct dm_pool *mem __attribute__((unused)),
@@ -225,11 +221,27 @@ static int _selected_disp(struct dm_report *rh,
        return dm_report_field_int(rh, field, &row->selected);
 }
 
+static const struct dm_report_object_type _implicit_common_report_types[] = {
+       { COMMON_REPORT_TYPE, "Common", "common_", _null_returning_fn },
+       { 0, "", "", NULL }
+};
+
 static const struct dm_report_field_type _implicit_common_report_fields[] = {
+       { COMMON_REPORT_TYPE, DM_REPORT_FIELD_TYPE_NUMBER, 0, 8, COMMON_FIELD_HELP_ID, "Help", _no_report_fn, "Show help." },
+       { COMMON_REPORT_TYPE, DM_REPORT_FIELD_TYPE_NUMBER, 0, 8, COMMON_FIELD_HELP_ALT_ID, "Help", _no_report_fn, "Show help." },
+       { 0, 0, 0, 0, "", "", 0, 0}
+};
+
+static const struct dm_report_field_type _implicit_common_report_fields_with_selection[] = {
        { COMMON_REPORT_TYPE, DM_REPORT_FIELD_TYPE_NUMBER, 0, 8, COMMON_FIELD_SELECTED_ID, "Selected", _selected_disp, "Item passes selection criteria." },
+       { COMMON_REPORT_TYPE, DM_REPORT_FIELD_TYPE_NUMBER, 0, 8, COMMON_FIELD_HELP_ID, "Help", _no_report_fn, "Show help." },
+       { COMMON_REPORT_TYPE, DM_REPORT_FIELD_TYPE_NUMBER, 0, 8, COMMON_FIELD_HELP_ALT_ID, "Help", _no_report_fn, "Show help." },
        { 0, 0, 0, 0, "", "", 0, 0}
 };
 
+static const struct dm_report_object_type *_implicit_report_types = _implicit_common_report_types;
+static const struct dm_report_field_type *_implicit_report_fields = _implicit_common_report_fields;
+
 static const struct dm_report_object_type *_find_type(struct dm_report *rh,
                                                      uint32_t report_type)
 {
@@ -940,10 +952,7 @@ static int _parse_fields(struct dm_report *rh, const char *format,
                if (!_field_match(rh, ws, (size_t) (we - ws), report_type_only)) {
                        _display_fields(rh, 1, 0);
                        log_warn(" ");
-                       if (strcasecmp(ws, DM_REPORT_FIELD_RESERVED_NAME_HELP) &&
-                           strcmp(ws, DM_REPORT_FIELD_RESERVED_NAME_HELP_ALT))
-                               log_error("Unrecognised field: %.*s",
-                                         (int) (we - ws), ws);
+                       log_error("Unrecognised field: %.*s", (int) (we - ws), ws);
                        return 0;
                }
        }
@@ -970,10 +979,7 @@ static int _parse_keys(struct dm_report *rh, const char *keys,
                if (!_key_match(rh, ws, (size_t) (we - ws), report_type_only)) {
                        _display_fields(rh, 1, 0);
                        log_warn(" ");
-                       if (strcasecmp(ws, DM_REPORT_FIELD_RESERVED_NAME_HELP) &&
-                           strcmp(ws, DM_REPORT_FIELD_RESERVED_NAME_HELP_ALT))
-                               log_error("dm_report: Unrecognised field: %.*s",
-                                         (int) (we - ws), ws);
+                       log_error("dm_report: Unrecognised field: %.*s", (int) (we - ws), ws);
                        return 0;
                }
        }
@@ -1015,6 +1021,20 @@ static void _dm_report_init_update_types(struct dm_report *rh, uint32_t *report_
                *report_types &= ~type->id;
 }
 
+static int _help_requested(struct dm_report *rh)
+{
+       struct field_properties *fp;
+
+       dm_list_iterate_items(fp, &rh->field_props) {
+               if (fp->implicit &&
+                   (!strcmp(_implicit_report_fields[fp->field_num].id, COMMON_FIELD_HELP_ID) ||
+                    !strcmp(_implicit_report_fields[fp->field_num].id, COMMON_FIELD_HELP_ALT_ID)))
+                       return 1;
+       }
+
+       return 0;
+}
+
 struct dm_report *dm_report_init(uint32_t *report_types,
                                 const struct dm_report_object_type *types,
                                 const struct dm_report_field_type *fields,
@@ -1098,6 +1118,12 @@ struct dm_report *dm_report_init(uint32_t *report_types,
         */
        _dm_report_init_update_types(rh, report_types);
 
+       if (_help_requested(rh)) {
+               _display_fields(rh, 1, 0);
+               log_warn(" ");
+               rh->flags |= RH_ALREADY_REPORTED;
+       }
+
        return rh;
 }
 
@@ -1406,6 +1432,9 @@ int dm_report_object(struct dm_report *rh, void *object)
                goto out;
        }
 
+       if (rh->flags & RH_ALREADY_REPORTED)
+               return 1;
+
        if (!(row = dm_pool_zalloc(rh->mem, sizeof(*row)))) {
                log_error("dm_report_object: struct row allocation failed");
                goto out;
@@ -2615,8 +2644,7 @@ struct dm_report *dm_report_init_with_selection(uint32_t *report_types,
        struct selection_node *root = NULL;
        const char *fin, *next;
 
-       _implicit_report_types = _implicit_common_report_types;
-       _implicit_report_fields = _implicit_common_report_fields;
+       _implicit_report_fields = _implicit_common_report_fields_with_selection;
 
        if (!(rh = dm_report_init(report_types, types, fields, output_fields,
                        output_separator, output_flags, sort_keys, private_data)))
@@ -2640,8 +2668,8 @@ struct dm_report *dm_report_init_with_selection(uint32_t *report_types,
                _display_fields(rh, 0, 1);
                log_warn(" ");
                _display_selection_help(rh);
-               dm_report_free(rh);
-               return NULL;
+               rh->flags |= RH_ALREADY_REPORTED;
+               return rh;
        }
 
        if (!(root = _alloc_selection_node(rh->mem, SEL_OR)))

diff --git a/tools/reporter.c b/tools/reporter.c
index 1e91f8f6c9e7e00ea6f7dfd62a9d008d067a7954..b08d97b71d6fade00df5c058a975545d0108ac1c 100644 (file)
--- a/tools/reporter.c
+++ b/tools/reporter.c
@@ -354,17 +354,8 @@ static int _report(struct cmd_context *cmd, int argc, char **argv,
        if (!(report_handle = report_init(cmd, options, keys, &report_type,
                                          separator, aligned, buffered,
                                          headings, field_prefixes, quoted,
-                                         columns_as_rows, selection))) {
-               if ( (!strcasecmp(options, DM_REPORT_FIELD_RESERVED_NAME_HELP) ||
-                     !strcmp(options, DM_REPORT_FIELD_RESERVED_NAME_HELP_ALT)) ||
-                    (!strcasecmp(keys, DM_REPORT_FIELD_RESERVED_NAME_HELP) ||
-                     !strcmp(keys, DM_REPORT_FIELD_RESERVED_NAME_HELP_ALT)) ||
-                    (selection &&
-                     (!strcasecmp(selection, DM_REPORT_FIELD_RESERVED_NAME_HELP) ||
-                      !strcmp(selection, DM_REPORT_FIELD_RESERVED_NAME_HELP_ALT))) )
-                       return r;
+                                         columns_as_rows, selection)))
                return_ECMD_FAILED;
-       }
 
        /* Ensure options selected are compatible */
        if (report_type & SEGS)