chore(core/embed): delete unused utf8 functions

[no changelog]

core/embed/lib/utf8.c

@@ -1,55 +0,0 @@
-/*
- * This file is part of the Trezor project, https://trezor.io/
- *
- * Copyright (c) SatoshiLabs
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "utf8.h"
-
-#define UTF8_IS_CONT(ch) (((ch)&0xC0) == 0x80)
-
-void utf8_substr(const char *buf_start, size_t buf_len, int char_off,
-                 int char_len, const char **out_start, int *out_len) {
-  size_t i = 0;
-
-  for (; i < buf_len; i++) {
-    if (char_off == 0) {
-      break;
-    }
-    if (!UTF8_IS_CONT(buf_start[i])) {
-      char_off--;
-    }
-  }
-  size_t i_start = i;
-
-  for (; i < buf_len; i++) {
-    if (char_len == 0) {
-      break;
-    }
-    if (!UTF8_IS_CONT(buf_start[i])) {
-      char_len--;
-    }
-  }
-
-  for (; i < buf_len; i++) {
-    if (!UTF8_IS_CONT(buf_start[i])) {
-      break;
-    }
-  }
-
-  *out_start = buf_start + i_start;
-  *out_len = i - i_start;
-}

core/embed/lib/utf8.h

@@ -1,30 +0,0 @@
-/*
- * This file is part of the Trezor project, https://trezor.io/
- *
- * Copyright (c) SatoshiLabs
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef LIB_UTF8_H
-#define LIB_UTF8_H
-
-#include <stddef.h>
-#include <stdint.h>
-
-// helper for locating a substring in buffer with utf-8 string
-void utf8_substr(const char *buf_start, size_t buf_len, int char_off,
-                 int char_len, const char **out_start, int *out_len);
-
-#endif  // LIB_UTF8_H