Rename all private sources and headers to C++ files

So we can liberally use the simple features of C++ that parts of the
codebase is already using.
diff --git a/src/hb-common.cc b/src/hb-common.cc
new file mode 100644
index 0000000..ece0980
--- /dev/null
+++ b/src/hb-common.cc
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2009,2010  Red Hat, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ */
+
+#include "hb-private.hh"
+
+HB_BEGIN_DECLS
+
+
+/* hb_tag_t */
+
+hb_tag_t
+hb_tag_from_string (const char *s)
+{
+  char tag[4];
+  unsigned int i;
+
+  if (!s || !*s)
+    return HB_TAG_NONE;
+
+  for (i = 0; i < 4 && s[i]; i++)
+    tag[i] = s[i];
+  for (; i < 4; i++)
+    tag[i] = ' ';
+
+  return HB_TAG_CHAR4 (tag);
+}
+
+
+/* hb_language_t */
+
+struct _hb_language_t {
+  const char s[1];
+};
+
+static const char canon_map[256] = {
+   0,   0,   0,   0,   0,   0,   0,   0,    0,   0,   0,   0,   0,   0,   0,   0,
+   0,   0,   0,   0,   0,   0,   0,   0,    0,   0,   0,   0,   0,   0,   0,   0,
+   0,   0,   0,   0,   0,   0,   0,   0,    0,   0,   0,   0,   0,  '-',  0,   0,
+  '0', '1', '2', '3', '4', '5', '6', '7',  '8', '9',  0,   0,   0,   0,   0,   0,
+  '-', 'a', 'b', 'c', 'd', 'e', 'f', 'g',  'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
+  'p', 'q', 'r', 's', 't', 'u', 'v', 'w',  'x', 'y', 'z',  0,   0,   0,   0,  '-',
+   0,  'a', 'b', 'c', 'd', 'e', 'f', 'g',  'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
+  'p', 'q', 'r', 's', 't', 'u', 'v', 'w',  'x', 'y', 'z',  0,   0,   0,   0,   0
+};
+
+static hb_bool_t
+lang_equal (const void *v1,
+	    const void *v2)
+{
+  const unsigned char *p1 = (const unsigned char *) v1;
+  const unsigned char *p2 = (const unsigned char *) v2;
+
+  while (canon_map[*p1] && canon_map[*p1] == canon_map[*p2])
+    {
+      p1++, p2++;
+    }
+
+  return (canon_map[*p1] == canon_map[*p2]);
+}
+
+#if 0
+static unsigned int
+lang_hash (const void *key)
+{
+  const unsigned char *p = key;
+  unsigned int h = 0;
+  while (canon_map[*p])
+    {
+      h = (h << 5) - h + canon_map[*p];
+      p++;
+    }
+
+  return h;
+}
+#endif
+
+
+hb_language_t
+hb_language_from_string (const char *str)
+{
+  static unsigned int num_langs;
+  static unsigned int num_alloced;
+  static hb_language_t *langs;
+  unsigned int i;
+  unsigned char *p;
+
+  /* TODO Use a hash table or something */
+
+  if (!str || !*str)
+    return NULL;
+
+  for (i = 0; i < num_langs; i++)
+    if (lang_equal (str, langs[i]->s))
+      return langs[i];
+
+  if (unlikely (num_langs == num_alloced)) {
+    unsigned int new_alloced = 2 * (8 + num_alloced);
+    hb_language_t *new_langs = (hb_language_t *) realloc (langs, new_alloced * sizeof (langs[0]));
+    if (!new_langs)
+      return NULL;
+    num_alloced = new_alloced;
+    langs = new_langs;
+  }
+
+  langs[i] = (hb_language_t) strdup (str);
+  for (p = (unsigned char *) langs[i]->s; *p; p++)
+    *p = canon_map[*p];
+
+  num_langs++;
+
+  return langs[i];
+}
+
+const char *
+hb_language_to_string (hb_language_t language)
+{
+  return language->s;
+}
+
+
+/* hb_script_t */
+
+hb_script_t
+hb_script_from_iso15924_tag (hb_tag_t tag)
+{
+  if (unlikely (tag == HB_TAG_NONE))
+    return HB_SCRIPT_INVALID;
+
+  /* Be lenient, adjust case (one capital letter followed by three small letters) */
+  tag = (tag & 0xDFDFDFDF) | 0x00202020;
+
+  switch (tag) {
+    case HB_TAG('C','y','r','s'): return HB_SCRIPT_CYRILLIC;
+    case HB_TAG('G','e','o','a'): return HB_SCRIPT_GEORGIAN;
+    case HB_TAG('G','e','o','n'): return HB_SCRIPT_GEORGIAN;
+    case HB_TAG('L','a','t','f'): return HB_SCRIPT_LATIN;
+    case HB_TAG('L','a','t','g'): return HB_SCRIPT_LATIN;
+    case HB_TAG('S','y','r','e'): return HB_SCRIPT_SYRIAC;
+    case HB_TAG('S','y','r','j'): return HB_SCRIPT_SYRIAC;
+    case HB_TAG('S','y','r','n'): return HB_SCRIPT_SYRIAC;
+  }
+
+  /* If it looks right, just use the tag as a script */
+  if (((uint32_t) tag & 0xE0E0E0E0) == 0x40606060)
+    return (hb_script_t) tag;
+
+  /* Otherwise, return unknown */
+  return HB_SCRIPT_UNKNOWN;
+}
+
+hb_script_t
+hb_script_from_string (const char *s)
+{
+  return hb_script_from_iso15924_tag (hb_tag_from_string (s));
+}
+
+hb_tag_t
+hb_script_to_iso15924_tag (hb_script_t script)
+{
+  return (hb_tag_t) script;
+}
+
+hb_direction_t
+hb_script_get_horizontal_direction (hb_script_t script)
+{
+  switch ((hb_tag_t) script)
+  {
+    case HB_SCRIPT_ARABIC:
+    case HB_SCRIPT_HEBREW:
+    case HB_SCRIPT_SYRIAC:
+    case HB_SCRIPT_THAANA:
+
+    /* Unicode-4.0 additions */
+    case HB_SCRIPT_CYPRIOT:
+
+    /* Unicode-5.0 additions */
+    case HB_SCRIPT_PHOENICIAN:
+    case HB_SCRIPT_NKO:
+
+    /* Unicode-5.2 additions */
+    case HB_SCRIPT_AVESTAN:
+    case HB_SCRIPT_IMPERIAL_ARAMAIC:
+    case HB_SCRIPT_INSCRIPTIONAL_PAHLAVI:
+    case HB_SCRIPT_INSCRIPTIONAL_PARTHIAN:
+    case HB_SCRIPT_OLD_SOUTH_ARABIAN:
+    case HB_SCRIPT_OLD_TURKIC:
+    case HB_SCRIPT_SAMARITAN:
+
+    /* Unicode-6.0 additions */
+    case HB_SCRIPT_MANDAIC:
+
+      return HB_DIRECTION_RTL;
+  }
+
+  return HB_DIRECTION_LTR;
+}
+
+
+HB_END_DECLS