Imported Upstream version 0.9.1upstream/0.9.1

1 files changed, 130 insertions, 0 deletions

diff --git a/lib/unistr/u32-to-u16.c b/lib/unistr/u32-to-u16.c
new file mode 100644
index 00000000..3a32162c
--- /dev/null
+++ b/lib/unistr/u32-to-u16.c
@@ -0,0 +1,130 @@
+/* Convert UTF-32 string to UTF-16 string.
+   Copyright (C) 2002, 2006-2007 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2002.
+
+   This program 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 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
+   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 <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "unistr.h"
+
+#define FUNC u32_to_u16
+#define SRC_UNIT uint32_t
+#define DST_UNIT uint16_t
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+DST_UNIT *
+FUNC (const SRC_UNIT *s, size_t n, DST_UNIT *resultbuf, size_t *lengthp)
+{
+  const SRC_UNIT *s_end = s + n;
+  /* Output string accumulator.  */
+  DST_UNIT *result;
+  size_t allocated;
+  size_t length;
+
+  if (resultbuf != NULL)
+    {
+      result = resultbuf;
+      allocated = *lengthp;
+    }
+  else
+    {
+      result = NULL;
+      allocated = 0;
+    }
+  length = 0;
+  /* Invariants:
+     result is either == resultbuf or == NULL or malloc-allocated.
+     If length > 0, then result != NULL.  */
+
+  while (s < s_end)
+    {
+      ucs4_t uc;
+      int count;
+
+      /* Fetch a Unicode character from the input string.  */
+      uc = *s++;
+      /* No need to call the safe variant u32_mbtouc, because
+	 u16_uctomb will verify uc anyway.  */
+
+      /* Store it in the output string.  */
+      count = u16_uctomb (result + length, uc, allocated - length);
+      if (count == -1)
+	{
+	  if (!(result == resultbuf || result == NULL))
+	    free (result);
+	  errno = EILSEQ;
+	  return NULL;
+	}
+      if (count == -2)
+	{
+	  DST_UNIT *memory;
+
+	  allocated = (allocated > 0 ? 2 * allocated : 12);
+	  if (length + 2 > allocated)
+	    allocated = length + 2;
+	  if (result == resultbuf || result == NULL)
+	    memory = (DST_UNIT *) malloc (allocated * sizeof (DST_UNIT));
+	  else
+	    memory =
+	      (DST_UNIT *) realloc (result, allocated * sizeof (DST_UNIT));
+
+	  if (memory == NULL)
+	    {
+	      if (!(result == resultbuf || result == NULL))
+		free (result);
+	      errno = ENOMEM;
+	      return NULL;
+	    }
+	  if (result == resultbuf && length > 0)
+	    memcpy ((char *) memory, (char *) result,
+		    length * sizeof (DST_UNIT));
+	  result = memory;
+	  count = u16_uctomb (result + length, uc, allocated - length);
+	  if (count < 0)
+	    abort ();
+	}
+      length += count;
+    }
+
+  if (length == 0)
+    {
+      if (result == NULL)
+	{
+	  /* Return a non-NULL value.  NULL means error.  */
+	  result = (DST_UNIT *) malloc (1);
+	  if (result == NULL)
+	    {
+	      errno = ENOMEM;
+	      return NULL;
+	    }
+	}
+    }
+  else if (result != resultbuf && length < allocated)
+    {
+      /* Shrink the allocated memory if possible.  */
+      DST_UNIT *memory;
+
+      memory = (DST_UNIT *) realloc (result, length * sizeof (DST_UNIT));
+      if (memory != NULL)
+	result = memory;
+    }
+
+  *lengthp = length;
+  return result;
+}