[buffer] Templatize UTF-* functions

src/hb-buffer.cc

@@ -1298,6 +1298,8 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
 		   unsigned int  item_offset,
 		   int           item_length)
 {
+  typedef hb_utf_t<T> utf_t;
+
   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE ||
 	  (!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID));
 
@@ -1305,7 +1307,7 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
     return;
 
   if (text_length == -1)
-    text_length = hb_utf_strlen (text);
+    text_length = utf_t::strlen (text);
 
   if (item_length == -1)
     item_length = text_length - item_offset;
@@ -1328,7 +1330,7 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
     while (start < prev && buffer->context_len[0] < buffer->CONTEXT_LENGTH)
     {
       hb_codepoint_t u;
-      prev = hb_utf_prev (prev, start, &u);
+      prev = utf_t::prev (prev, start, &u);
       buffer->context[0][buffer->context_len[0]++] = u;
     }
   }
@@ -1339,7 +1341,7 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
   {
     hb_codepoint_t u;
     const T *old_next = next;
-    next = hb_utf_next (next, end, &u);
+    next = utf_t::next (next, end, &u);
     buffer->add (u, old_next - (const T *) text);
   }
 
@@ -1349,7 +1351,7 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
   while (next < end && buffer->context_len[1] < buffer->CONTEXT_LENGTH)
   {
     hb_codepoint_t u;
-    next = hb_utf_next (next, end, &u);
+    next = utf_t::next (next, end, &u);
     buffer->context[1][buffer->context_len[1]++] = u;
   }
 

src/hb-utf-private.hh

@@ -29,14 +29,19 @@
 
 #include "hb-private.hh"
 
+template <typename T, bool validate=true> struct hb_utf_t;
+
 
 /* UTF-8 */
 
-static inline const uint8_t *
-hb_utf_next (const uint8_t *text,
+template <>
+struct hb_utf_t<uint8_t, true>
+{
+  static inline const uint8_t *
+  next (const uint8_t *text,
 	const uint8_t *end,
 	hb_codepoint_t *unicode)
-{
+  {
     /* Written to only accept well-formed sequences.
      * Based on ideas from ICU's U8_NEXT.
      * Generates a -1 for each ill-formed byte. */
@@ -95,42 +100,45 @@ hb_utf_next (const uint8_t *text,
     *unicode = c;
     return text;
 
-error:
+  error:
     *unicode = -1;
     return text;
-}
+  }
 
-static inline const uint8_t *
-hb_utf_prev (const uint8_t *text,
+  static inline const uint8_t *
+  prev (const uint8_t *text,
 	const uint8_t *start,
 	hb_codepoint_t *unicode)
-{
+  {
     const uint8_t *end = text--;
     while (start < text && (*text & 0xc0) == 0x80 && end - text < 4)
       text--;
 
-  if (likely (hb_utf_next (text, end, unicode) == end))
+    if (likely (next (text, end, unicode) == end))
       return text;
 
     *unicode = -1;
     return end - 1;
-}
-
+  }
 
-static inline unsigned int
-hb_utf_strlen (const uint8_t *text)
-{
-  return strlen ((const char *) text);
-}
+  static inline unsigned int
+  strlen (const uint8_t *text)
+  {
+    return ::strlen ((const char *) text);
+  }
+};
 
 
 /* UTF-16 */
 
-static inline const uint16_t *
-hb_utf_next (const uint16_t *text,
+template <>
+struct hb_utf_t<uint16_t, true>
+{
+  static inline const uint16_t *
+  next (const uint16_t *text,
 	const uint16_t *end,
 	hb_codepoint_t *unicode)
-{
+  {
     hb_codepoint_t c = *text++;
 
     if (likely (!hb_in_range (c, 0xD800u, 0xDFFFu)))
@@ -155,13 +163,13 @@ hb_utf_next (const uint16_t *text,
     /* Lonely / out-of-order surrogate. */
     *unicode = -1;
     return text;
-}
+  }
 
-static inline const uint16_t *
-hb_utf_prev (const uint16_t *text,
+  static inline const uint16_t *
+  prev (const uint16_t *text,
 	const uint16_t *start,
 	hb_codepoint_t *unicode)
-{
+  {
     const uint16_t *end = text--;
     hb_codepoint_t c = *text;
 
@@ -174,57 +182,62 @@ hb_utf_prev (const uint16_t *text,
     if (likely (start < text && hb_in_range (c, 0xDC00u, 0xDFFFu)))
       text--;
 
-  if (likely (hb_utf_next (text, end, unicode) == end))
+    if (likely (next (text, end, unicode) == end))
       return text;
 
     *unicode = -1;
     return end - 1;
-}
+  }
 
 
-static inline unsigned int
-hb_utf_strlen (const uint16_t *text)
-{
+  static inline unsigned int
+  strlen (const uint16_t *text)
+  {
     unsigned int l = 0;
     while (*text++) l++;
     return l;
-}
+  }
+};
 
 
 /* UTF-32 */
 
-static inline const uint32_t *
-hb_utf_next (const uint32_t *text,
+template <bool validate>
+struct hb_utf_t<uint32_t, validate>
+{
+  static inline const uint32_t *
+  next (const uint32_t *text,
 	const uint32_t *end HB_UNUSED,
 	hb_codepoint_t *unicode)
-{
+  {
     hb_codepoint_t c = *text++;
-  if (unlikely (c > 0x10FFFFu || hb_in_range (c, 0xD800u, 0xDFFFu)))
+    if (validate && unlikely (c > 0x10FFFFu || hb_in_range (c, 0xD800u, 0xDFFFu)))
       goto error;
     *unicode = c;
     return text;
 
-error:
+  error:
     *unicode = -1;
     return text;
-}
+  }
 
-static inline const uint32_t *
-hb_utf_prev (const uint32_t *text,
+  static inline const uint32_t *
+  prev (const uint32_t *text,
 	const uint32_t *start HB_UNUSED,
 	hb_codepoint_t *unicode)
-{
-  hb_utf_next (text - 1, text, unicode);
+  {
+    next (text - 1, text, unicode);
     return text - 1;
-}
+  }
 
-static inline unsigned int
-hb_utf_strlen (const uint32_t *text)
-{
+  static inline unsigned int
+  strlen (const uint32_t *text)
+  {
     unsigned int l = 0;
     while (*text++) l++;
     return l;
-}
+  }
+};
 
 
 #endif /* HB_UTF_PRIVATE_HH */