Simplify char16_t implementation

1 files changed, 34 insertions, 41 deletions

diff --git a/wcsmbs/mbrtoc16.c b/wcsmbs/mbrtoc16.c
index df970fba4f..f5ed2b4ac9 100644
--- a/wcsmbs/mbrtoc16.c
+++ b/wcsmbs/mbrtoc16.c
@@ -30,12 +30,6 @@
 # define EILSEQ EINVAL
 #endif
 
-#if __STDC__ >= 201000L
-# define U(c) U##c
-#else
-# define U(c) L##c
-#endif
-
 
 /* This is the private state used if PS is NULL.  */
 static mbstate_t state;
@@ -46,6 +40,11 @@ mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
   if (ps == NULL)
     ps = &state;
 
+  /* The standard text does not say that S being NULL means the state
+     is reset even if the second half of a surrogate still have to be
+     returned.  In fact, the error code description indicates
+     otherwise.  Therefore always first try to return a second
+     half.  */
   if (ps->__count & 0x80000000)
     {
       /* We have to return the second word for a surrogate.  */
@@ -55,13 +54,13 @@ mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
       return (size_t) -3;
     }
 
-  char16_t buf[2];
+  wchar_t wc;
   struct __gconv_step_data data;
   int status;
   size_t result;
   size_t dummy;
   const unsigned char *inbuf, *endbuf;
-  unsigned char *outbuf = (unsigned char *) buf;
+  unsigned char *outbuf = (unsigned char *) &wc;
   const struct gconv_fcts *fcts;
 
   /* Set information for this step.  */
@@ -75,14 +74,14 @@ mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
      initial state.  */
   if (s == NULL)
     {
-      outbuf = (unsigned char *) buf;
+      pc16 = NULL;
       s = "";
       n = 1;
     }
 
   /* Tell where we want the result.  */
   data.__outbuf = outbuf;
-  data.__outbufend = outbuf + sizeof (char16_t);
+  data.__outbufend = outbuf + sizeof (wchar_t);
 
   /* Get the conversion functions.  */
   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
@@ -91,28 +90,20 @@ mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
   inbuf = (const unsigned char *) s;
   endbuf = inbuf + n;
   if (__builtin_expect (endbuf < inbuf, 0))
-    endbuf = (const unsigned char *) ~(uintptr_t) 0;
-  __gconv_fct fct = fcts->toc16->__fct;
+    {
+      endbuf = (const unsigned char *) ~(uintptr_t) 0;
+      if (endbuf == inbuf)
+	goto ilseq;
+    }
+  __gconv_fct fct = fcts->towc->__fct;
 #ifdef PTR_DEMANGLE
-  if (fcts->toc16->__shlib_handle != NULL)
+  if (fcts->towc->__shlib_handle != NULL)
     PTR_DEMANGLE (fct);
 #endif
 
-  /* We first have to check whether the character can be represented
-     without a surrogate.  If we immediately pass in a buffer large
-     enough to hold two char16_t values and the first character does
-     not require a surrogate the routine will try to convert more
-     input if N is larger then needed for the first character.  */
-  status = DL_CALL_FCT (fct, (fcts->toc16, &data, &inbuf, endbuf,
+  status = DL_CALL_FCT (fct, (fcts->towc, &data, &inbuf, endbuf,
 			      NULL, &dummy, 0, 1));
 
-  if (status == __GCONV_FULL_OUTPUT && data.__outbuf == outbuf)
-    {
-      data.__outbufend = outbuf + 2 * sizeof (char16_t);
-      status = DL_CALL_FCT (fct, (fcts->toc16, &data, &inbuf, endbuf,
-				  NULL, &dummy, 0, 1));
-    }
-
   /* There must not be any problems with the conversion but illegal input
      characters.  The output buffer must be large enough, otherwise the
      definition of MB_CUR_MAX is not correct.  All the other possible
@@ -125,33 +116,35 @@ mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
       || status == __GCONV_FULL_OUTPUT)
     {
-      if (pc16 != NULL)
-	*pc16 = buf[0];
+      result = inbuf - (const unsigned char *) s;
 
-      if (data.__outbuf != outbuf && *(char16_t *) outbuf == U('\0'))
+      if (wc < 0x10000)
 	{
-	  /* The converted character is the NUL character.  */
-	  assert (__mbsinit (data.__statep));
-	  result = 0;
+	  if (pc16 != NULL)
+	    *pc16 = wc;
+
+	  if (data.__outbuf != outbuf && wc == L'\0')
+	    {
+	      /* The converted character is the NUL character.  */
+	      assert (__mbsinit (data.__statep));
+	      result = 0;
+	    }
 	}
       else
 	{
-	  result = inbuf - (const unsigned char *) s;
+	  /* This is a surrogate.  */
+	  if (pc16 != NULL)
+	    *pc16 = 0xd7c0 + (wc >> 10);
 
-	  if (data.__outbuf != outbuf + 2)
-	    {
-	      /* This is a surrogate.  */
-	      assert (buf[0] >= 0xd800 && buf[0] <= 0xdfff);
-	      assert (buf[1] >= 0xdc00 && buf[1] <= 0xdfff);
-	      ps->__count |= 0x80000000;
-	      ps->__value.__wch = buf[1];
-	    }
+	  ps->__count |= 0x80000000;
+	  ps->__value.__wch = 0xdc00 + (wc & 0x3ff);
 	}
     }
   else if (status == __GCONV_INCOMPLETE_INPUT)
     result = (size_t) -2;
   else
     {
+    ilseq:
       result = (size_t) -1;
       __set_errno (EILSEQ);
     }