%compute-applicable-methods in Scheme

[bpt/guile.git] / libguile / regex-posix.c

diff --git a/libguile/regex-posix.c b/libguile/regex-posix.c
index a95cfb8..bec0f89 100644 (file)
--- a/libguile/regex-posix.c
+++ b/libguile/regex-posix.c
@@ -1,4 +1,4 @@
-/*     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2006, 2007 Free Software Foundation, Inc.
+/*     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2006, 2007, 2010, 2011, 2012 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -35,22 +35,10 @@
 
 #include "libguile/_scm.h"
 
-/* Supposedly, this file is never compiled unless we know we have
-   POSIX regular expressions.  But we still put this in an #ifdef so
-   the file is CPP'able (for dependency scanning) even on systems that
-   don't have a <regex.h> header.  */
-#ifdef HAVE_REGCOMP
-#ifdef HAVE_REGEX_H
 #include <regex.h>
-#else
-#ifdef HAVE_RXPOSIX_H
-#include <rxposix.h>           /* GNU Rx library */
-#else
-#ifdef HAVE_RX_RXPOSIX_H
-#include <rx/rxposix.h>                /* GNU Rx library on Linux */
-#endif
-#endif
-#endif
+
+#ifdef HAVE_WCHAR_H
+#include <wchar.h>
 #endif
 
 #include "libguile/async.h"
@@ -173,7 +161,7 @@ SCM_DEFINE (scm_make_regexp, "make-regexp", 1, 0, 1,
       flag = SCM_CDR (flag);
     }
 
-  rx = scm_gc_malloc (sizeof(regex_t), "regex");
+  rx = scm_gc_malloc_pointerless (sizeof (regex_t), "regex");
   c_pat = scm_to_locale_string (pat);
   status = regcomp (rx, c_pat,
                    /* Make sure they're not passing REG_NOSUB;
@@ -196,6 +184,43 @@ SCM_DEFINE (scm_make_regexp, "make-regexp", 1, 0, 1,
 }
 #undef FUNC_NAME
 
+#ifdef HAVE_WCHAR_H
+/*
+ * While regexec does respect the current locale, it returns byte
+ * offsets instead of character offsets. This routine fixes up the
+ * regmatch_t structures to refer to characters instead. See "Converting
+ * a Character" in the libc manual, for more details.
+ */
+static void
+fixup_multibyte_match (regmatch_t *matches, int nmatches, char *str)
+{
+  mbstate_t state;
+  int i;
+  size_t char_idx, byte_idx;
+  size_t nbytes = 1; /* just to kick off the for loop */
+
+  memset (&state, '\0', sizeof (state));
+
+  for (char_idx = byte_idx = 0; nbytes > 0; char_idx++, byte_idx += nbytes)
+    {
+      for (i = 0; i < nmatches; ++i)
+        {
+          if (matches[i].rm_so == byte_idx)
+            matches[i].rm_so = char_idx;
+          if (matches[i].rm_eo == byte_idx)
+            matches[i].rm_eo = char_idx;
+        }
+
+      nbytes = mbrlen (str + byte_idx, MB_LEN_MAX, &state);
+      if (nbytes == (size_t) -2 || nbytes == (size_t) -1)
+        /* Something is wrong. Shouldn't be possible, as the regex match
+           succeeded.  */
+        abort ();
+    }
+
+}
+#endif
+
 SCM_DEFINE (scm_regexp_exec, "regexp-exec", 2, 2, 0,
             (SCM rx, SCM str, SCM start, SCM flags),
            "Match the compiled regular expression @var{rx} against\n"
@@ -256,11 +281,18 @@ SCM_DEFINE (scm_regexp_exec, "regexp-exec", 2, 2, 0,
   /* re_nsub doesn't account for the `subexpression' representing the
      whole regexp, so add 1 to nmatches. */
 
+  c_str = scm_to_locale_string (substr);
+
   nmatches = SCM_RGX(rx)->re_nsub + 1;
   matches = scm_malloc (sizeof (regmatch_t) * nmatches);
-  c_str = scm_to_locale_string (substr);
   status = regexec (SCM_RGX (rx), c_str, nmatches, matches,
                    scm_to_int (flags));
+
+#ifdef HAVE_WCHAR_H
+  if (!status)
+    fixup_multibyte_match (matches, nmatches, c_str);
+#endif
+
   free (c_str);
 
   if (!status)