keysyms: Add XKB_KEYSYM_NAME_MAX_SIZE for internal use

Currently there is no indication of the maximum length of keysym names.

This is statically known, so add the new *internal* following API:
`XKB_KEYSYM_NAME_MAX_SIZE`.

scripts/update-headers.py

@@ -19,20 +19,28 @@ def load_keysyms(path: Path) -> dict[str, int]:
     keysym_max = 0
     min_unicode_keysym = 0x01000100
     max_unicode_keysym = 0x0110FFFF
-    keysyms = set()
+    canonical_names: dict[int, str] = {}
+    max_unicode_name = "U10FFFF"
+    max_keysym_name = "0x1fffffff"  # XKB_KEYSYM_MAX
     with path.open("rt", encoding="utf-8") as fd:
         for line in fd:
             if m := KEYSYM_PATTERN.match(line):
                 value = int(m.group("value"), 16)
-                keysyms.add(value)
                 keysym_min = min(keysym_min, value)
                 keysym_max = max(keysym_max, value)
+                if value not in canonical_names:
+                    canonical_names[value] = m.group("name")
     return {
         "XKB_KEYSYM_MIN_ASSIGNED": min(keysym_min, min_unicode_keysym),
         "XKB_KEYSYM_MAX_ASSIGNED": max(keysym_max, max_unicode_keysym),
         "XKB_KEYSYM_MIN_EXPLICIT": keysym_min,
         "XKB_KEYSYM_MAX_EXPLICIT": keysym_max,
-        "XKB_KEYSYM_COUNT_EXPLICIT": len(keysyms),
+        "XKB_KEYSYM_COUNT_EXPLICIT": len(canonical_names),
+        "XKB_KEYSYM_NAME_MAX_SIZE": max(
+            max(len(name) for name in canonical_names.values()),
+            len(max_unicode_name),
+            len(max_keysym_name),
+        ),
     }
 
 

src/keysym.h

@@ -76,6 +76,8 @@
 #define XKB_KEYSYM_UNICODE_MIN    0x01000100
 /** Maximum Unicode keysym, correspoding to the maximum Unicode code point */
 #define XKB_KEYSYM_UNICODE_MAX    0x0110ffff
+/** Maximum keysym name length */
+#define XKB_KEYSYM_NAME_MAX_SIZE  27
 
 bool
 xkb_keysym_is_assigned(xkb_keysym_t ks);

src/keysym.h.jinja

@@ -76,6 +76,8 @@
 #define XKB_KEYSYM_UNICODE_MIN    0x01000100
 /** Maximum Unicode keysym, correspoding to the maximum Unicode code point */
 #define XKB_KEYSYM_UNICODE_MAX    0x0110ffff
+/** Maximum keysym name length */
+#define XKB_KEYSYM_NAME_MAX_SIZE  {{ XKB_KEYSYM_NAME_MAX_SIZE }}
 
 bool
 xkb_keysym_is_assigned(xkb_keysym_t ks);

src/text.c

@@ -27,6 +27,7 @@
 #include "config.h"
 
 #include "keymap.h"
+#include "keysym.h"
 #include "text.h"
 
 bool
@@ -235,8 +236,8 @@ ActionTypeText(enum xkb_action_type type)
 const char *
 KeysymText(struct xkb_context *ctx, xkb_keysym_t sym)
 {
-    char *buffer = xkb_context_get_buffer(ctx, 64);
-    xkb_keysym_get_name(sym, buffer, 64);
+    char *buffer = xkb_context_get_buffer(ctx, XKB_KEYSYM_NAME_MAX_SIZE);
+    xkb_keysym_get_name(sym, buffer, XKB_KEYSYM_NAME_MAX_SIZE);
     return buffer;
 }
 

test/common.c

@@ -47,6 +47,7 @@
 
 #include "test.h"
 #include "utils.h"
+#include "src/keysym.h"
 
 /*
  * Test a sequence of keysyms, resulting from a sequence of key presses,
@@ -76,7 +77,7 @@ test_key_seq_va(struct xkb_keymap *keymap, va_list ap)
     const xkb_keysym_t *syms;
     xkb_keysym_t sym;
     unsigned int nsyms, i;
-    char ksbuf[64];
+    char ksbuf[XKB_KEYSYM_NAME_MAX_SIZE];
 
     fprintf(stderr, "----\n");
 

test/compose.c

@@ -28,6 +28,7 @@
 
 #include "test.h"
 #include "src/utf8.h"
+#include "src/keysym.h"
 #include "src/compose/parser.h"
 #include "src/compose/dump.h"
 
@@ -73,7 +74,7 @@ test_compose_seq_va(struct xkb_compose_table *table, va_list ap)
 {
     int ret;
     struct xkb_compose_state *state;
-    char buffer[64];
+    char buffer[XKB_KEYSYM_NAME_MAX_SIZE];
 
     state = xkb_compose_state_new(table, XKB_COMPOSE_STATE_NO_FLAGS);
     assert(state);

test/keysym.c

@@ -56,7 +56,7 @@ test_casestring(const char *string, xkb_keysym_t expected)
 static int
 test_keysym(xkb_keysym_t keysym, const char *expected)
 {
-    char s[16];
+    char s[XKB_KEYSYM_NAME_MAX_SIZE];
 
     xkb_keysym_get_name(keysym, s, sizeof(s));
 
@@ -117,11 +117,11 @@ get_keysym_name(xkb_keysym_t keysym, char *buffer, size_t size)
 static int
 test_utf32_to_keysym(uint32_t ucs, xkb_keysym_t expected)
 {
-    char expected_name[64];
-    char actual_name[64];
+    char expected_name[XKB_KEYSYM_NAME_MAX_SIZE];
+    char actual_name[XKB_KEYSYM_NAME_MAX_SIZE];
     xkb_keysym_t actual = xkb_utf32_to_keysym(ucs);
-    get_keysym_name(expected, expected_name, 64);
-    get_keysym_name(actual, actual_name, 64);
+    get_keysym_name(expected, expected_name, XKB_KEYSYM_NAME_MAX_SIZE);
+    get_keysym_name(actual, actual_name, XKB_KEYSYM_NAME_MAX_SIZE);
 
     fprintf(stderr, "Code point 0x%lx: expected keysym: %s, actual: %s\n\n",
             (unsigned long)ucs, expected_name, actual_name);
@@ -183,6 +183,10 @@ main(void)
         char utf8[7];
         int needed = xkb_keysym_to_utf8(ks, utf8, sizeof(utf8));
         assert(0 <= needed && needed <= 5);
+        /* Check maximum name length */
+        char name[XKB_KEYSYM_NAME_MAX_SIZE];
+        needed = xkb_keysym_iterator_get_name(iter, name, sizeof(name));
+        assert(0 < needed && (size_t)needed <= sizeof(name));
     }
     iter = xkb_keysym_iterator_unref(iter);
     assert(ks_prev == XKB_KEYSYM_MAX_ASSIGNED);

tools/compile-compose.c

@@ -31,6 +31,7 @@
 #include "xkbcommon/xkbcommon-keysyms.h"
 #include "xkbcommon/xkbcommon-compose.h"
 #include "src/compose/dump.h"
+#include "src/keysym.h"
 
 static void
 usage(FILE *fp, char *progname)
@@ -57,7 +58,7 @@ print_compose_table_entry(struct xkb_compose_table_entry *entry)
 {
     size_t nsyms;
     const xkb_keysym_t *syms = xkb_compose_table_entry_sequence(entry, &nsyms);
-    char buf[128];
+    char buf[XKB_KEYSYM_NAME_MAX_SIZE];
     for (size_t i = 0; i < nsyms; i++) {
         xkb_keysym_get_name(syms[i], buf, sizeof(buf));
         printf("<%s>", buf);

tools/how-to-type.c

@@ -30,6 +30,7 @@
 #include <errno.h>
 
 #include "xkbcommon/xkbcommon.h"
+#include "src/keysym.h"
 
 #define ARRAY_SIZE(arr) ((sizeof(arr) / sizeof(*(arr))))
 
@@ -57,7 +58,7 @@ main(int argc, char *argv[])
     uint32_t codepoint;
     xkb_keysym_t keysym;
     int ret;
-    char name[200];
+    char name[XKB_KEYSYM_NAME_MAX_SIZE];
     struct xkb_keymap *keymap = NULL;
     xkb_keycode_t min_keycode, max_keycode;
     xkb_mod_index_t num_mods;

tools/tools-common.c

@@ -49,6 +49,8 @@
 #endif
 
 #include "tools-common.h"
+#include "src/utils.h"
+#include "src/keysym.h"
 
 static void
 print_keycode(struct xkb_keymap *keymap, const char* prefix,
@@ -155,7 +157,9 @@ tools_print_keycode_state(char *prefix,
     xkb_keysym_t sym;
     const xkb_keysym_t *syms;
     int nsyms;
-    char s[16];
+    // FIXME: this buffer is used for xkb_compose_state_get_utf8,
+    // which can have a length up to 256. Need to import this constant from compose.
+    char s[MAX(16, XKB_KEYSYM_NAME_MAX_SIZE)];
     xkb_layout_index_t layout;
     enum xkb_compose_status status;