Update BSD grep to the latest development version. It has some code

backported that was written for the TRE integration project in Google
Summer of Code 2011.  This is a temporary solution until the whole
regex library is not replaced so that BSD grep development can continue
and the backported code gets some review and testing.  This change only
improves scalability slightly, there is no big performance boost yet
but several minor bugs have been found and fixed.

Approved by:	delphij (mentor)
Sposored by:	Google Summer of Code 2011
MFC after:	1 week

1 files changed, 103 insertions, 0 deletions

diff --git a/usr.bin/grep/regex/tre-compile.c b/usr.bin/grep/regex/tre-compile.c
new file mode 100644
index 0000000..f037c49
--- /dev/null
+++ b/usr.bin/grep/regex/tre-compile.c
@@ -0,0 +1,103 @@
+/*      $FreeBSD$       */
+
+#include "glue.h"
+
+#include <stdio.h>
+#include <assert.h>
+#include <errno.h>
+#include <regex.h>
+#include <string.h>
+#include <wchar.h>
+
+#include "xmalloc.h"
+
+int
+tre_convert_pattern(const char *regex, size_t n, tre_char_t **w,
+		    size_t *wn)
+{
+#if TRE_WCHAR
+  tre_char_t *wregex;
+  size_t wlen;
+
+  wregex = xmalloc(sizeof(tre_char_t) * (n + 1));
+  if (wregex == NULL)
+    return REG_ESPACE;
+
+  /* If the current locale uses the standard single byte encoding of
+     characters, we don't do a multibyte string conversion.  If we did,
+     many applications which use the default locale would break since
+     the default "C" locale uses the 7-bit ASCII character set, and
+     all characters with the eighth bit set would be considered invalid. */
+#if TRE_MULTIBYTE
+  if (TRE_MB_CUR_MAX == 1)
+#endif /* TRE_MULTIBYTE */
+    {
+      unsigned int i;
+      const unsigned char *str = (const unsigned char *)regex;
+      tre_char_t *wstr = wregex;
+
+      for (i = 0; i < n; i++)
+	*(wstr++) = *(str++);
+      wlen = n;
+    }
+#if TRE_MULTIBYTE
+  else
+    {
+      int consumed;
+      tre_char_t *wcptr = wregex;
+#ifdef HAVE_MBSTATE_T
+      mbstate_t state;
+      memset(&state, '\0', sizeof(state));
+#endif /* HAVE_MBSTATE_T */
+      while (n > 0)
+	{
+	  consumed = tre_mbrtowc(wcptr, regex, n, &state);
+
+	  switch (consumed)
+	    {
+	    case 0:
+	      if (*regex == '\0')
+		consumed = 1;
+	      else
+		{
+		  xfree(wregex);
+		  return REG_BADPAT;
+		}
+	      break;
+	    case -1:
+	      DPRINT(("mbrtowc: error %d: %s.\n", errno, strerror(errno)));
+	      xfree(wregex);
+	      return REG_BADPAT;
+	    case -2:
+	      /* The last character wasn't complete.  Let's not call it a
+		 fatal error. */
+	      consumed = n;
+	      break;
+	    }
+	  regex += consumed;
+	  n -= consumed;
+	  wcptr++;
+	}
+      wlen = wcptr - wregex;
+    }
+#endif /* TRE_MULTIBYTE */
+  wregex[wlen] = L'\0';
+  *w = wregex;
+  *wn = wlen;
+  return REG_OK;
+#else /* !TRE_WCHAR */
+  {
+    *w = (tre_char_t * const *)regex;
+    *wn = n;
+    return REG_OK;
+  }
+#endif /* !TRE_WCHAR */
+}
+
+void
+tre_free_pattern(tre_char_t *wregex)
+{
+#if TRE_WCHAR
+  xfree(wregex);
+#endif
+}