gdb

	* c-lang.c (c_emit_char): Use INTERMEDIATE_ENCODING.
	(c_printstr): Likewise.
	* charset.c: Include gdb_wait.h.
	(make_wchar_iterator): Use INTERMEDIATE_ENCODING.
	(find_charset_names): Use pexecute.  Handle libiconv's output.
	Detect errors.
	(_initialize_charset): Use xstrdup.
	* gdb_wchar.h: Check HAVE_BTOWC.  Split PHONY_ICONV and wchar
	cases.
	(INTERMEDIATE_ENCODING): New define.
	* configure, config.in: Rebuild.
	* configure.ac: Check for btowc.
gdb/doc
	* gdb.texinfo (Character Sets): Document default character set.

9 files changed, 152 insertions, 41 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8dfdfc8edf9..689552e7c93 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,18 @@
+2009-04-14  Tom Tromey  <tromey@redhat.com>
+
+	* c-lang.c (c_emit_char): Use INTERMEDIATE_ENCODING.
+	(c_printstr): Likewise.
+	* charset.c: Include gdb_wait.h.
+	(make_wchar_iterator): Use INTERMEDIATE_ENCODING.
+	(find_charset_names): Use pexecute.  Handle libiconv's output.
+	Detect errors.
+	(_initialize_charset): Use xstrdup.
+	* gdb_wchar.h: Check HAVE_BTOWC.  Split PHONY_ICONV and wchar
+	cases.
+	(INTERMEDIATE_ENCODING): New define.
+	* configure, config.in: Rebuild.
+	* configure.ac: Check for btowc.
+
 2009-04-15  Tom Tromey  <tromey@redhat.com>
 
 	* c-lang.c (evaluate_subexp_c): Correctly handle EVAL_SKIP.
diff --git a/gdb/c-lang.c b/gdb/c-lang.c
index 86de9334ce0..027e9b292fb 100644
--- a/gdb/c-lang.c
+++ b/gdb/c-lang.c
@@ -296,7 +296,7 @@ c_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
   obstack_init (&output);
   make_cleanup_obstack_free (&output);
 
-  convert_between_encodings ("wchar_t", host_charset (),
+  convert_between_encodings (INTERMEDIATE_ENCODING, host_charset (),
 			     obstack_base (&wchar_buf),
 			     obstack_object_size (&wchar_buf),
 			     1, &output, translit_char);
@@ -562,7 +562,7 @@ c_printstr (struct ui_file *stream, struct type *type, const gdb_byte *string,
   obstack_init (&output);
   make_cleanup_obstack_free (&output);
 
-  convert_between_encodings ("wchar_t", host_charset (),
+  convert_between_encodings (INTERMEDIATE_ENCODING, host_charset (),
 			     obstack_base (&wchar_buf),
 			     obstack_object_size (&wchar_buf),
 			     1, &output, translit_char);
diff --git a/gdb/charset.c b/gdb/charset.c
index 7dd0f40fb03..c77463814df 100644
--- a/gdb/charset.c
+++ b/gdb/charset.c
@@ -22,6 +22,7 @@
 #include "gdbcmd.h"
 #include "gdb_assert.h"
 #include "gdb_obstack.h"
+#include "gdb_wait.h"
 #include "charset-list.h"
 #include "vec.h"
 
@@ -536,7 +537,7 @@ make_wchar_iterator (const gdb_byte *input, size_t bytes, const char *charset,
   struct wchar_iterator *result;
   iconv_t desc;
 
-  desc = iconv_open ("wchar_t", charset);
+  desc = iconv_open (INTERMEDIATE_ENCODING, charset);
   if (desc == (iconv_t) -1)
     perror_with_name ("Converting character sets");
 
@@ -707,35 +708,92 @@ find_charset_names (void)
 static void
 find_charset_names (void)
 {
-  FILE *in;
+  struct pex_obj *child;
+  char *args[3];
+  int err, status;
+  int fail = 1;
+
+  child = pex_init (0, "iconv", NULL);
+
+  args[0] = "iconv";
+  args[1] = "-l";
+  args[2] = NULL;
+  /* Note that we simply ignore errors here.  */
+  if (!pex_run (child, PEX_SEARCH | PEX_STDERR_TO_STDOUT, "iconv",
+		args, NULL, NULL, &err))
+    {
+      FILE *in = pex_read_output (child, 0);
+
+      /* POSIX says that iconv -l uses an unspecified format.  We
+	 parse the glibc and libiconv formats; feel free to add others
+	 as needed.  */
+      while (!feof (in))
+	{
+	  /* The size of buf is chosen arbitrarily.  */
+	  char buf[1024];
+	  char *start, *r;
+	  int len, keep_going;
+
+	  r = fgets (buf, sizeof (buf), in);
+	  if (!r)
+	    break;
+	  len = strlen (r);
+	  if (len <= 3)
+	    continue;
+	  /* Strip off the newline.  */
+	  --len;
+	  /* Strip off one or two '/'s.  glibc will print lines like
+	     "8859_7//", but also "10646-1:1993/UCS4/".  */
+	  if (buf[len - 1] == '/')
+	    --len;
+	  if (buf[len - 1] == '/')
+	    --len;
+	  buf[len] = '\0';
+
+	  /* libiconv will print multiple entries per line, separated
+	     by spaces.  */
+	  start = buf;
+	  while (1)
+	    {
+	      int keep_going;
+	      char *p;
+
+	      /* Find the next space, or end-of-line.  */
+	      for (p = start; *p && *p != ' '; ++p)
+		;
+	      /* Ignore an empty result.  */
+	      if (p == start)
+		break;
+	      keep_going = *p;
+	      *p = '\0';
+	      VEC_safe_push (char_ptr, charsets, xstrdup (start));
+	      if (!keep_going)
+		break;
+	      /* Skip any extra spaces.  */
+	      for (start = p + 1; *start && *start == ' '; ++start)
+		;
+	    }
+	}
 
-  in = popen ("iconv -l", "r");
-  /* It is ok to ignore errors; we'll fall back on a default.  */
-  if (!in)
-    return;
+      if (pex_get_status (child, 1, &status)
+	  && WIFEXITED (status) && !WEXITSTATUS (status))
+	fail = 0;
 
-  /* POSIX says that iconv -l uses an unspecified format.  We parse
-     the glibc format; feel free to add others as needed.  */
-  while (!feof (in))
-    {
-      /* The size of buf is chosen arbitrarily.  A character set name
-	 longer than this would not be very nice.  */
-      char buf[80];
-      int len;
-      char *r = fgets (buf, sizeof (buf), in);
-      if (!r)
-	break;
-      len = strlen (r);
-      if (len <= 3)
-	continue;
-      if (buf[len - 2] == '/' && buf[len - 3] == '/')
-	buf[len - 3] = '\0';
-      VEC_safe_push (char_ptr, charsets, xstrdup (buf));
     }
 
-  pclose (in);
+  pex_free (child);
 
-  VEC_safe_push (char_ptr, charsets, NULL);
+  if (fail)
+    {
+      /* Some error occurred, so drop the vector.  */
+      int ix;
+      char *elt;
+      for (ix = 0; VEC_iterate (char_ptr, charsets, ix, elt); ++ix)
+	xfree (elt);
+      VEC_truncate (char_ptr, charsets, 0);
+    }
+  else
+    VEC_safe_push (char_ptr, charsets, NULL);
 }
 
 #endif /* HAVE_ICONVLIST || HAVE_LIBICONVLIST */
@@ -748,7 +806,7 @@ _initialize_charset (void)
 
   /* The first element is always "auto"; then we skip it for the
      commands where it is not allowed.  */
-  VEC_safe_push (char_ptr, charsets, "auto");
+  VEC_safe_push (char_ptr, charsets, xstrdup ("auto"));
   find_charset_names ();
 
   if (VEC_length (char_ptr, charsets) > 1)
diff --git a/gdb/config.in b/gdb/config.in
index 0d5effa81fd..ab0c84019f6 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -70,6 +70,9 @@
 /* Define to 1 if you have the <bp-sym.h> header file. */
 #undef HAVE_BP_SYM_H
 
+/* Define to 1 if you have the `btowc' function. */
+#undef HAVE_BTOWC
+
 /* Define to 1 if you have the `canonicalize_file_name' function. */
 #undef HAVE_CANONICALIZE_FILE_NAME
 
diff --git a/gdb/configure b/gdb/configure
index 51f35f5c1f7..e06a4510cc6 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -15776,10 +15776,11 @@ fi
 
 
 
+
 for ac_func in canonicalize_file_name realpath getrusage getuid \
                 getgid poll pread64 sbrk setpgid setpgrp setsid \
 		sigaction sigprocmask sigsetmask socketpair syscall \
-		ttrace wborder setlocale iconvlist libiconvlist
+		ttrace wborder setlocale iconvlist libiconvlist btowc
 do
 as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
 echo "$as_me:$LINENO: checking for $ac_func" >&5
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 821dffe2db3..88bd8a653af 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -796,7 +796,7 @@ AC_FUNC_VFORK
 AC_CHECK_FUNCS([canonicalize_file_name realpath getrusage getuid \
                 getgid poll pread64 sbrk setpgid setpgrp setsid \
 		sigaction sigprocmask sigsetmask socketpair syscall \
-		ttrace wborder setlocale iconvlist libiconvlist])
+		ttrace wborder setlocale iconvlist libiconvlist btowc])
 AM_LANGINFO_CODESET
 
 # Check the return and argument types of ptrace.  No canned test for
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 89d7d114e66..68ba957f360 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2009-04-15  Tom Tromey  <tromey@redhat.com>
+
+	* gdb.texinfo (Character Sets): Document default character set.
+
 2009-04-14  Pierre Muller  <muller@ics.u-strasbg.fr>
 
 	* gdbint.texinfo: Change server name from sources.redhat.com to
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 5269dfcfc93..ebba32fc2b7 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -7998,7 +7998,9 @@ Set the current host character set to @var{charset}.
 
 By default, @value{GDBN} uses a host character set appropriate to the
 system it is running on; you can override that default using the
-@code{set host-charset} command.
+@code{set host-charset} command.  On some systems, @value{GDBN} cannot
+automatically determine the appropriate host character set.  In this
+case, @value{GDBN} uses @samp{UTF-8}.
 
 @value{GDBN} can only use certain character sets as its host character
 set.  If you type @kbd{@w{set target-charset @key{TAB}@key{TAB}}},
diff --git a/gdb/gdb_wchar.h b/gdb/gdb_wchar.h
index 583140eeb53..07a6c877cf4 100644
--- a/gdb/gdb_wchar.h
+++ b/gdb/gdb_wchar.h
@@ -19,13 +19,36 @@
 #ifndef GDB_WCHAR_H
 #define GDB_WCHAR_H
 
-/* If this host has wchar_t and if iconv is available (perhaps via GNU
-   libiconv), then we arrange to use those.  Otherwise, we provide a
-   phony iconv which only handles a single character set, and we
-   provide wrappers for the wchar_t functionality we use.  */
-#if defined(HAVE_ICONV) && defined(HAVE_WCHAR_H)
-
+/* We handle three different modes here.
+   
+   Capable systems have the full suite: wchar_t support and iconv
+   (perhaps via GNU libiconv).  On these machines, full functionality
+   is available.
+   
+   DJGPP is known to have libiconv but not wchar_t support.  On
+   systems like this, we use the narrow character functions.  The full
+   functionality is available to the user, but many characters (those
+   outside the narrow range) will be displayed as escapes.
+   
+   Finally, some systems do not have iconv.  Here we provide a phony
+   iconv which only handles a single character set, and we provide
+   wrappers for the wchar_t functionality we use.  */
+
+
+#define INTERMEDIATE_ENCODING "wchar_t"
+
+#if defined (HAVE_ICONV)
 #include <iconv.h>
+#else
+/* This define is used elsewhere so we don't need to duplicate the
+   same checking logic in multiple places.  */
+#define PHONY_ICONV
+#endif
+
+/* We use "btowc" as a sentinel to detect functioning wchar_t
+   support.  */
+#if defined (HAVE_ICONV) && defined (HAVE_WCHAR_H) && defined (HAVE_BTOWC)
+
 #include <wchar.h>
 #include <wctype.h>
 
@@ -53,10 +76,15 @@ typedef int gdb_wint_t;
 
 #define LCST(X) X
 
-/* This define is used elsewhere so we don't need to duplicate the
-   same checking logic in multiple places.  */
-#define PHONY_ICONV
+/* If we are using the narrow character set, we want to use the host
+   narrow encoding as our intermediate encoding.  However, if we are
+   also providing a phony iconv, we might as well just stick with
+   "wchar_t".  */
+#ifndef PHONY_ICONV
+#undef INTERMEDIATE_ENCODING
+#define INTERMEDIATE_ENCODING host_charset ()
+#endif
 
-#endif /* defined(HAVE_ICONV) && defined(HAVE_WCHAR_H) */
+#endif
 
 #endif /* GDB_WCHAR_H */