Adding upstream version 9.4.upstream/9.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 267 insertions, 0 deletions

diff --git a/lib/mbuiter.h b/lib/mbuiter.h
new file mode 100644
index 0000000..862efa3
--- /dev/null
+++ b/lib/mbuiter.h
@@ -0,0 +1,267 @@
+/* Iterating through multibyte strings: macros for multi-byte encodings.
+   Copyright (C) 2001, 2005, 2007, 2009-2023 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>.  */
+
+/* The macros in this file implement forward iteration through a
+   multi-byte string, without knowing its length a-priori.
+
+   With these macros, an iteration loop that looks like
+
+      char *iter;
+      for (iter = buf; *iter != '\0'; iter++)
+        {
+          do_something (*iter);
+        }
+
+   becomes
+
+      mbui_iterator_t iter;
+      for (mbui_init (iter, buf); mbui_avail (iter); mbui_advance (iter))
+        {
+          do_something (mbui_cur_ptr (iter), mb_len (mbui_cur (iter)));
+        }
+
+   The benefit of these macros over plain use of mbrtowc is:
+   - Handling of invalid multibyte sequences is possible without
+     making the code more complicated, while still preserving the
+     invalid multibyte sequences.
+
+   Compared to mbiter.h, the macros here don't need to know the string's
+   length a-priori.  The downside is that at each step, the look-ahead
+   that guards against overrunning the terminating '\0' is more expensive.
+   The mbui_* macros are therefore suitable when there is a high probability
+   that only the first few multibyte characters need to be inspected.
+   Whereas the mbi_* macros are better if usually the iteration runs
+   through the entire string.
+
+   mbui_iterator_t
+     is a type usable for variable declarations.
+
+   mbui_init (iter, startptr)
+     initializes the iterator, starting at startptr.
+
+   mbui_avail (iter)
+     returns true if there are more multibyte characters available before
+     the end of string is reached. In this case, mbui_cur (iter) is
+     initialized to the next multibyte character.
+
+   mbui_advance (iter)
+     advances the iterator by one multibyte character.
+
+   mbui_cur (iter)
+     returns the current multibyte character, of type mbchar_t.  All the
+     macros defined in mbchar.h can be used on it.
+
+   mbui_cur_ptr (iter)
+     return a pointer to the beginning of the current multibyte character.
+
+   mbui_reloc (iter, ptrdiff)
+     relocates iterator when the string is moved by ptrdiff bytes.
+
+   mbui_copy (&destiter, &srciter)
+     copies srciter to destiter.
+
+   Here are the function prototypes of the macros.
+
+   extern void          mbui_init (mbui_iterator_t iter, const char *startptr);
+   extern bool          mbui_avail (mbui_iterator_t iter);
+   extern void          mbui_advance (mbui_iterator_t iter);
+   extern mbchar_t      mbui_cur (mbui_iterator_t iter);
+   extern const char *  mbui_cur_ptr (mbui_iterator_t iter);
+   extern void          mbui_reloc (mbui_iterator_t iter, ptrdiff_t ptrdiff);
+   extern void          mbui_copy (mbui_iterator_t *new, const mbui_iterator_t *old);
+ */
+
+#ifndef _MBUITER_H
+#define _MBUITER_H 1
+
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE,
+   _GL_ATTRIBUTE_ALWAYS_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <uchar.h>
+#include <wchar.h>
+
+#include "mbchar.h"
+#include "strnlen1.h"
+
+_GL_INLINE_HEADER_BEGIN
+#ifndef MBUITER_INLINE
+# define MBUITER_INLINE _GL_INLINE _GL_ATTRIBUTE_ALWAYS_INLINE
+#endif
+
+struct mbuiter_multi
+{
+  #if !GNULIB_MBRTOC32_REGULAR
+  bool in_shift;        /* true if next byte may not be interpreted as ASCII */
+                        /* If GNULIB_MBRTOC32_REGULAR, it is always false,
+                           so optimize it away.  */
+  #endif
+  mbstate_t state;      /* if in_shift: current shift state */
+                        /* If GNULIB_MBRTOC32_REGULAR, it is in an initial state
+                           before and after every mbuiter_multi_next invocation.
+                         */
+  bool next_done;       /* true if mbui_avail has already filled the following */
+  unsigned int cur_max; /* A cache of MB_CUR_MAX.  */
+  struct mbchar cur;    /* the current character:
+        const char *cur.ptr          pointer to current character
+        The following are only valid after mbui_avail.
+        size_t cur.bytes             number of bytes of current character
+        bool cur.wc_valid            true if wc is a valid 32-bit wide character
+        char32_t cur.wc              if wc_valid: the current character
+        */
+};
+
+MBUITER_INLINE void
+mbuiter_multi_next (struct mbuiter_multi *iter)
+{
+  if (iter->next_done)
+    return;
+  #if !GNULIB_MBRTOC32_REGULAR
+  if (iter->in_shift)
+    goto with_shift;
+  #endif
+  /* Handle most ASCII characters quickly, without calling mbrtowc().  */
+  if (is_basic (*iter->cur.ptr))
+    {
+      /* These characters are part of the POSIX portable character set.
+         For most of them, namely those in the ISO C basic character set,
+         ISO C 99 guarantees that their wide character code is identical to
+         their char code.  For the few other ones, this is the case as well,
+         in all locale encodings that are in use.  The 32-bit wide character
+         code is the same as well.  */
+      iter->cur.bytes = 1;
+      iter->cur.wc = *iter->cur.ptr;
+      iter->cur.wc_valid = true;
+    }
+  else
+    {
+      assert (mbsinit (&iter->state));
+      #if !GNULIB_MBRTOC32_REGULAR
+      iter->in_shift = true;
+    with_shift:
+      #endif
+      iter->cur.bytes = mbrtoc32 (&iter->cur.wc, iter->cur.ptr,
+                                  strnlen1 (iter->cur.ptr, iter->cur_max),
+                                  &iter->state);
+      if (iter->cur.bytes == (size_t) -1)
+        {
+          /* An invalid multibyte sequence was encountered.  */
+          iter->cur.bytes = 1;
+          iter->cur.wc_valid = false;
+          /* Allow the next invocation to continue from a sane state.  */
+          #if !GNULIB_MBRTOC32_REGULAR
+          iter->in_shift = false;
+          #endif
+          mbszero (&iter->state);
+        }
+      else if (iter->cur.bytes == (size_t) -2)
+        {
+          /* An incomplete multibyte character at the end.  */
+          iter->cur.bytes = strlen (iter->cur.ptr);
+          iter->cur.wc_valid = false;
+          /* Whether to set iter->in_shift = false and reset iter->state
+             or not is not important; the string end is reached anyway.  */
+        }
+      else
+        {
+          if (iter->cur.bytes == 0)
+            {
+              /* A null wide character was encountered.  */
+              iter->cur.bytes = 1;
+              assert (*iter->cur.ptr == '\0');
+              assert (iter->cur.wc == 0);
+            }
+          #if !GNULIB_MBRTOC32_REGULAR
+          else if (iter->cur.bytes == (size_t) -3)
+            /* The previous multibyte sequence produced an additional 32-bit
+               wide character.  */
+            iter->cur.bytes = 0;
+          #endif
+          iter->cur.wc_valid = true;
+
+          /* When in an initial state, we can go back treating ASCII
+             characters more quickly.  */
+          #if !GNULIB_MBRTOC32_REGULAR
+          if (mbsinit (&iter->state))
+            iter->in_shift = false;
+          #endif
+        }
+    }
+  iter->next_done = true;
+}
+
+MBUITER_INLINE void
+mbuiter_multi_reloc (struct mbuiter_multi *iter, ptrdiff_t ptrdiff)
+{
+  iter->cur.ptr += ptrdiff;
+}
+
+MBUITER_INLINE void
+mbuiter_multi_copy (struct mbuiter_multi *new_iter, const struct mbuiter_multi *old_iter)
+{
+  #if !GNULIB_MBRTOC32_REGULAR
+  if ((new_iter->in_shift = old_iter->in_shift))
+    memcpy (&new_iter->state, &old_iter->state, sizeof (mbstate_t));
+  else
+  #endif
+    mbszero (&new_iter->state);
+  new_iter->next_done = old_iter->next_done;
+  new_iter->cur_max = old_iter->cur_max;
+  mb_copy (&new_iter->cur, &old_iter->cur);
+}
+
+/* Iteration macros.  */
+typedef struct mbuiter_multi mbui_iterator_t;
+#if !GNULIB_MBRTOC32_REGULAR
+#define mbui_init(iter, startptr) \
+  ((iter).cur.ptr = (startptr), \
+   (iter).in_shift = false, mbszero (&(iter).state), \
+   (iter).next_done = false, \
+   (iter).cur_max = MB_CUR_MAX)
+#else
+/* Optimized: no in_shift.  */
+#define mbui_init(iter, startptr) \
+  ((iter).cur.ptr = (startptr), \
+   mbszero (&(iter).state), \
+   (iter).next_done = false, \
+   (iter).cur_max = MB_CUR_MAX)
+#endif
+#define mbui_avail(iter) \
+  (mbuiter_multi_next (&(iter)), !mb_isnul ((iter).cur))
+#define mbui_advance(iter) \
+  ((iter).cur.ptr += (iter).cur.bytes, (iter).next_done = false)
+
+/* Access to the current character.  */
+#define mbui_cur(iter) (iter).cur
+#define mbui_cur_ptr(iter) (iter).cur.ptr
+
+/* Relocation.  */
+#define mbui_reloc(iter, ptrdiff) mbuiter_multi_reloc (&iter, ptrdiff)
+
+/* Copying an iterator.  */
+#define mbui_copy mbuiter_multi_copy
+
+_GL_INLINE_HEADER_END
+
+#endif /* _MBUITER_H */