rules: Add support for :all qualifier

Some layout options require to be applied to every group to maintain
consistency (e.g. a group switcher). Currently this must be done manually
for all layout indexes. This is error prone and prevents the increase of
the maximum group count.

This commit introduces the `:all` qualifier for KcCGST values. When a
rule with this qualifier is matched, it will expands the qualified
value (and its optional merge mode) for every layout, e.g.
`+group(toggle):all` (respectively `|group(toggle)`) would expand to
`+group(toggle):1+group(toggle):2` (respectively
`|group(toggle):1|group(toggle):2`) if there are 2 layouts, etc.

If there is no merge mode, it defaults to *override* `+`, e.g. `x:all`
expands to `x:1+x:2+x:3` for 3 layouts.

Note that only the qualified *value* is expanded, e.g. `x+y:all` expands
to `x+y:1+y:2` for 2 layouts.

`:all` can be used in combination with special layout indexes. Since
this can lead to an unexpected behaviour, a warning will be raised.

changes/api/+modern-rules.feature.md

@@ -7,8 +7,9 @@ Rules: Added support for special layouts indexes:
   `layout[2]` .. `layout[4]`.
 - *any*: matches layout at any position. This is an index range.
 
-Also added the special index `%i` which correspond to the index of the matched
-layout.
+Also added:
+- the special index `%i` which correspond to the index of the matched layout.
+- the `:all` qualifier: it applies the qualified item to all layouts.
 
 See the [documentation](https://xkbcommon.org/doc/current/rule-file-format.html)
 for further information.

doc/rules-format.md

@@ -150,7 +150,8 @@ Kccgst       ::= "keycodes" | "symbols" | "types" | "compat" | "geometry"
 
 Rule         ::= { MlvoValue } "=" { KccgstValue } "\n"
 MlvoValue    ::= "*" | GroupName | <ident>
-KccgstValue  ::= <ident>
+KccgstValue  ::= <ident> [ { Qualifier } ]
+Qualifier    ::= ":" ({ NumericIndex } | "all")
 ```
 
 <!--
@@ -250,7 +251,7 @@ or %%H seems to do the job though.
     </dd>
     <dt>
         @anchor rules-i-expansion
-        `%%i`,
+        `:%%i`,
         `%%l[%%i]`,
         `%(l[%%i])`,
         etc.
@@ -267,6 +268,61 @@ or %%H seems to do the job though.
   instead of <code>(\%v[1])</code>. See @ref rules-symbols-example for
   an illustration.
 
+- @anchor rules-all-qualifier
+  Since version `1.8.0`, if a `Rule` is matched, the `:all` *qualifier* in the
+  `KccgstValue` applies the qualified value (and its optional merge mode) to all
+  layouts. If there is is no merge mode, it defaults to *override* `+`.
+
+  <table>
+    <caption>Examples of `:all` qualified use</caption>
+    <tr>
+        <th>`KccgstValue`</th>
+        <th>Layouts count</th>
+        <th>Final `KccgstValue`</th>
+    </tr>
+    <tr>
+        <td rowspan="2">`x:all`</td>
+        <td>1</td>
+        <td>`x:1`</td>
+    </tr>
+    <tr>
+        <td>2</td>
+        <td>`x:1+x:2`</td>
+    </tr>
+    <tr>
+        <td rowspan="2">`+x:all`</td>
+        <td>1</td>
+        <td>`+x:1`</td>
+    </tr>
+    <tr>
+        <td>3</td>
+        <td>`+x:1+x:2+x:3`</td>
+    </tr>
+    <tr>
+        <td rowspan="2">`|x:all`</td>
+        <td>1</td>
+        <td>`|x:1`</td>
+    </tr>
+    <tr>
+        <td>4</td>
+        <td>`|x:1|x:2|x:3|x:4`</td>
+    </tr>
+    <tr>
+        <td rowspan="2">`x|y:all`</td>
+        <td>1</td>
+        <td>`x|y:1`</td>
+    </tr>
+    <tr>
+        <td>3</td>
+        <td>`x|y:1|y:2|y:3`</td>
+    </tr>
+    <tr>
+        <td>`x:all+y|z:all`</td>
+        <td>2</td>
+        <td>`x:1+x:2+y|z:1|z:2`</td>
+    </tr>
+  </table>
+
 RMLVO resolution process {#rmlvo-resolution}
 ------------------------
 
@@ -392,22 +448,61 @@ Using the following example:
 ! layout = symbols
   *      = pc+%l%(v)
 
-! layout  option          = symbols
- $azerty  caps:digits_row = +capslock(digits_row)
-  *       misc:typo       = +typo(base)
-  *       lv3:ralt_alt    = +level3(ralt_alt)
- ```
+! layout[1] = symbols
+  *         = pc+%l[1]%(v[1])
+
+! layout[2] = symbols
+  *         = +%l[2]%(v[2])
+// Repeat the previous rules set with indexes 3 and 4
+
+! layout     option          = symbols
+ $azerty     caps:digits_row = +capslock(digits_row)
+  *          misc:typo       = +typo(base)
+  *          lv3:ralt_alt    = +level3(ralt_alt)
+
+! layout[1]  option          = symbols
+ $azerty     caps:digits_row = +capslock(digits_row):1
+  *          misc:typo       = +typo(base):1
+  *          lv3:ralt_alt    = +level3(ralt_alt):1
+// Repeat the previous rules set for indexes 2 to 4
+```
 
 we would have the following resolutions of <em>[symbols]</em>:
 
-| Layout  | Option                                   | Symbols                                                  |
-| ------- | ---------------------------------------- | -------------------------------------------------------- |
-| `be`    | `caps:digits_row`                        | `pc+be+capslock(digits_row)`                             |
-| `gb`    | `caps:digits_row`                        | `pc+gb`                                                  |
-| `fr`    | `misc:typo`                              | `pc+fr+typo(base)`                                       |
-| `fr`    | `misc:typo,caps:digits_row`              | `pc+fr+capslock(digits_row)+typo(base)`                  |
-| `fr`    | `lv3:ralt_alt,caps:digits_row,misc:typo` | `pc+fr+capslock(digits_row)+typo(base)+level3(ralt_alt)` |
-
-Note that the configuration with `gb` [layout] has no match for the [option]
-and that the order of the [options] in the [RMLVO] configuration has no
-influence on the resulting [symbols].
+| Layout  | Option                                   | Symbols                                                     |
+| ------- | ---------------------------------------- | ----------------------------------------------------------- |
+| `be`    | `caps:digits_row`                        | `pc+be+capslock(digits_row)`                                |
+| `gb`    | `caps:digits_row`                        | `pc+gb`                                                     |
+| `fr`    | `misc:typo`                              | `pc+fr+typo(base)`                                          |
+| `fr`    | `misc:typo,caps:digits_row`              | `pc+fr+capslock(digits_row)+typo(base)`                     |
+| `fr`    | `lv3:ralt_alt,caps:digits_row,misc:typo` | `pc+fr+capslock(digits_row)+typo(base)+level3(ralt_alt)`    |
+| `fr,gb` | `caps:digits_row,misc:typo`              | `pc+fr+gb:2+capslock(digits_row)+typo(base):1+typo(base):2` |
+
+Note that the configuration with `gb` [layout] has no match for the
+[option] `caps:digits_row` and that the order of the [options] in the
+[RMLVO] configuration has no influence on the resulting [symbols], as it
+depends solely on their order in the rules.
+
+Since version `1.8.0`, the previous code can be replaced with simply:
+
+```c
+! $azerty = be fr
+
+! layout[first] = symbols
+  *             = pc+%l[%i]%(v[%i])
+
+! layout[later] = symbols
+  *             = +%l[%i]%(v[%i])
+
+! layout[any]  option          = symbols
+ $azerty       caps:digits_row = +capslock(digits_row):%i
+
+! option       = symbols
+  misc:typo    = +typo(base):all
+  lv3:ralt_alt = +level3(ralt_alt):all
+
+// The previous is equivalent to:
+! layout[any]  option       = symbols
+  *            misc:typo    = +typo(base):%i
+  *            lv3:ralt_alt = +level3(ralt_alt):%i
+```

src/scanner-utils.h

@@ -57,18 +57,24 @@ struct scanner {
     void *priv;
 };
 
-#define scanner_log_with_code(scanner, level, log_msg_id, fmt, ...) \
-    xkb_log_with_code((scanner)->ctx, (level), 0, log_msg_id, \
-                      "%s:%zu:%zu: " fmt "\n", \
-                      (scanner)->file_name, \
-                      (scanner)->token_line, \
+#define scanner_log_with_code(scanner, level, verbosity, log_msg_id, fmt, ...) \
+    xkb_log_with_code((scanner)->ctx, (level), verbosity, log_msg_id,          \
+                      "%s:%zu:%zu: " fmt "\n",                                 \
+                      (scanner)->file_name,                                    \
+                      (scanner)->token_line,                                   \
                       (scanner)->token_column, ##__VA_ARGS__)
 
-#define scanner_err(scanner, id, fmt, ...) \
-    scanner_log_with_code(scanner, XKB_LOG_LEVEL_ERROR, id, fmt, ##__VA_ARGS__)
+#define scanner_err(scanner, id, fmt, ...)                     \
+    scanner_log_with_code(scanner, XKB_LOG_LEVEL_ERROR, 0, id, \
+                          fmt, ##__VA_ARGS__)
 
-#define scanner_warn(scanner, id, fmt, ...) \
-    scanner_log_with_code(scanner, XKB_LOG_LEVEL_WARNING, id, fmt, ##__VA_ARGS__)
+#define scanner_warn(scanner, id, fmt, ...)                      \
+    scanner_log_with_code(scanner, XKB_LOG_LEVEL_WARNING, 0, id, \
+                          fmt, ##__VA_ARGS__)
+
+#define scanner_vrb(scanner, verbosity, id, fmt, ...)                    \
+    scanner_log_with_code(scanner, XKB_LOG_LEVEL_WARNING, verbosity, id, \
+                          fmt, ##__VA_ARGS__)
 
 static inline void
 scanner_init(struct scanner *s, struct xkb_context *ctx,

src/xkbcomp/rules.c

@@ -1076,8 +1076,55 @@ expand_rmlvo_in_kccgst_value(struct matcher *m, struct scanner *s,
 }
 
 /*
- * This function performs %-expansion on @value (see overview above),
- * and appends the result to @to.
+ * This function performs :all replacement on @value (see overview above),
+ * and appends the result to @expanded.
+ */
+static void
+expand_qualifier_in_kccgst_value(
+    struct matcher *m, struct scanner *s,
+    struct sval value, darray_char *expanded,
+    bool has_layout_idx_range, bool has_separator,
+    unsigned int prefix_idx, unsigned int *i)
+{
+    const char *str = value.start;
+
+    /* “all” followed by nothing or by a layout separator */
+    if ((*i + 3 <= value.len || is_merge_mode_prefix(str[*i + 3])) &&
+        str[*i] == 'a' && str[*i+1] == 'l' && str[*i+2] == 'l') {
+        if (has_layout_idx_range)
+            scanner_vrb(s, 2, XKB_LOG_MESSAGE_NO_ID,
+                        "Using :all qualifier with indexes range "
+                        "is not recommended.");
+        /* Add at least one layout */
+        darray_appends_nullterminate(*expanded, "1", 1);
+        /* Check for more layouts (slow path) */
+        if (darray_size(m->rmlvo.layouts) > 1) {
+            char layout_index[MAX_LAYOUT_INDEX_STR_LENGTH + 1];
+            const size_t prefix_length = darray_size(*expanded) - prefix_idx - 1;
+            xkb_layout_index_t l;
+            for (l = 1;
+                 l < MIN(XKB_MAX_GROUPS, darray_size(m->rmlvo.layouts));
+                 l++)
+            {
+                if (!has_separator)
+                    darray_append(*expanded, MERGE_DEFAULT_PREFIX);
+                /* Append prefix */
+                darray_appends_nullterminate(*expanded,
+                                             &darray_item(*expanded, prefix_idx),
+                                             prefix_length);
+                /* Append index */
+                int count = snprintf(layout_index, sizeof(layout_index),
+                                     "%"PRIu32, l + 1);
+                darray_appends_nullterminate(*expanded, layout_index, count);
+            }
+        }
+        *i += 3;
+    }
+}
+
+/*
+ * This function performs %-expansion and :all-expansion on @value
+ * (see overview above), and appends the result to @to.
  */
 static bool
 append_expanded_kccgst_value(struct matcher *m, struct scanner *s,
@@ -1088,10 +1135,20 @@ append_expanded_kccgst_value(struct matcher *m, struct scanner *s,
     darray_char expanded = darray_new();
     char ch;
     bool expanded_plus, to_plus;
+    unsigned int last_item_idx = 0;
+    bool has_separator = false;
 
     for (unsigned i = 0; i < value.len; ) {
-        /* Check if that's a start of an expansion */
+        /* Check if that's a start of an expansion or qualifier */
         switch (str[i]) {
+            /* Qualifier */
+            case ':':
+                darray_appends_nullterminate(expanded, &str[i++], 1);
+                expand_qualifier_in_kccgst_value(m, s, value, &expanded,
+                                                 m->mapping.has_layout_idx_range,
+                                                 has_separator,
+                                                 last_item_idx, &i);
+                break;
             /* Expansion */
             case '%':
                 if (++i >= value.len ||
@@ -1103,6 +1160,8 @@ append_expanded_kccgst_value(struct matcher *m, struct scanner *s,
             case MERGE_OVERRIDE_PREFIX:
             case MERGE_AUGMENT_PREFIX:
                 darray_appends_nullterminate(expanded, &str[i++], 1);
+                last_item_idx = darray_size(expanded) - 1;
+                has_separator = true;
                 break;
             /* Just a normal character. */
             default:

test/data/rules/all_qualifier

@@ -0,0 +1,59 @@
+! model         = keycodes
+  my_model      = my_keycodes
+  *             = default_keycodes
+
+! layout        variant    = symbols
+  layout_a      my_variant = symbols_a+extra_variant
+
+! layout        = symbols
+  layout_a      = symbols_a
+  layout_b      = symbols_b
+  *             = default_symbols
+
+! layout[1]     = symbols
+  layout_a      = symbols_a:1
+  layout_b      = symbols_b:1
+  layout_x      = base:all // strange but valid
+  *             = default_symbols:1
+
+! layout[2]     = symbols
+  layout_a      = +symbols_a:2
+  layout_b      = +symbols_b:2
+  *             = +default_symbols:2
+
+! layout[3]     = symbols
+  layout_a      = +symbols_a:3
+  layout_b      = +symbols_b:3
+  *             = +default_symbols:3
+
+! layout[4]     = symbols
+  layout_a      = +symbols_a:4
+  layout_b      = +symbols_b:4
+  *             = +default_symbols:4
+
+// WARNING: Invalid at the moment. Here for future test
+! layout[5]     = symbols
+  layout_a      = +symbols_a:5
+  layout_b      = +symbols_b:5
+  layout_c      = +symbols_c:5
+  *             = +default_symbols:5
+
+// Combine with special indexes
+! layout[first] variant[first] = symbols
+  *             extra1         = +extra_symbols:all
+
+// Combine with special indexes (valid but raises a warning)
+! layout[any] variant[any] = symbols
+  *           extra2       = +extra_symbols1:%i+extra_symbols2:all
+  *           extra3       = +extra_symbols2:all+extra_symbols1:%i
+
+! model         = types
+  my_model      = my_types
+  *             = default_types
+
+! model         = compat
+  my_model      = my_compat
+  *             = default_compat
+
+! option        = symbols
+  my_option     = +extra_option:all

test/data/rules/all_qualifier-limit

@@ -0,0 +1,18 @@
+! model         = keycodes
+  *             = default_keycodes
+
+! layout[1]     = symbols
+  *             = x:all // force x on all groups
+
+! layout[later] = symbols
+  // skipped, as it has no explicit merge mode and
+  // thus is not appended to previous
+  *             = skip
+
+! model         = types
+  *             = default_types
+
+! model         = compat
+  *             = default_compat
+
+! option        = symbols

test/data/rules/evdev-modern

@@ -489,7 +489,6 @@
 
 ! layout[any]		option		=	symbols
   $threelevellayouts	grp:alts_toggle =	+level3(ralt_switch_for_alts_toggle):%i
-  *			misc:typo 	=	+typo(base):%i
   *			misc:apl	=	+apl(level3):%i
 
 ! option				=	symbols
@@ -692,6 +691,7 @@
   lv5:lwin_switch_lock_cancel		=	+level5(lwin_switch_lock_cancel)
   lv5:rwin_switch_lock_cancel		=	+level5(rwin_switch_lock_cancel)
   parens:swap_brackets			=	+parens(swap_brackets)
+  misc:typo				=	+typo(base):all
 
 
 ! option		=	compat