2009-07-10 Phil Muldoon <pmuldoon@redhat.com>

	* python/python-internal.h (apply_varobj_pretty_printer): Update
	definition.
	(python_string_to_target_python_string): Add definition.
	* python/python-utils.c (unicode_to_encoded_python_string)
	(unicode_to_target_python_string)
	(python_string_to_target_python_string): New Functions.
	* python/python-prettyprint.c (pretty_print_one_value): Likewise.
	(print_string_repr): Refactor to logic to account for PyObject
	returned strings.
	(apply_varobj_pretty_printer): Likewise.
	* python/python-value.c (valpy_string): Parse length keyword. Use
	length keyword in LA_GET_STRING.
	* varobj.c (value_get_print_value): Refactor logic to account for
	PyObject returned strings.
	* c-lang.c (c_get_string): If the length parameter is specified,
	use that. Return value in characters. Update comments.
	* language.h: Update c_get_string prototype comments.

2009-07-10  Phil Muldoon  <pmuldoon@redhat.com>

	* gdb.texinfo (Values From Inferior): Add length parameter
	description.

2009-07-10 Phil Muldoon  <pmuldoon@redhat.com>

	* gdb.python/python-prettyprint.c: Add counted null string
	structure.
	* gdb.python/python-prettyprint.exp: Print null string. Test for
	embedded nulls.
	* gdb.python/python-prettyprint.py (pp_ns): New Function.
	* gdb.python/python-value.exp (test_value_in_inferior): Add
	variable length string fetch tests.
	* gdb.python/python-value.c (main): Add strings for string fetch tests.

4 files changed, 108 insertions, 45 deletions

diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 39d37e1..67a78af 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -113,14 +113,15 @@ void gdbpy_print_stack (void);
 PyObject *python_string_to_unicode (PyObject *obj);
 char *unicode_to_target_string (PyObject *unicode_str);
 char *python_string_to_target_string (PyObject *obj);
+PyObject *python_string_to_target_python_string (PyObject *obj);
 char *python_string_to_host_string (PyObject *obj);
 PyObject *target_string_to_unicode (const gdb_byte *str, int length);
 int gdbpy_is_string (PyObject *obj);
 
 /* Note that these are declared here, and not in python.h with the
    other pretty-printer functions, because they refer to PyObject.  */
-char *apply_varobj_pretty_printer (PyObject *print_obj,
-				   struct value **replacement);
+PyObject *apply_varobj_pretty_printer (PyObject *print_obj,
+				       struct value **replacement);
 PyObject *gdbpy_get_varobj_pretty_printer (struct value *value);
 char *gdbpy_get_display_hint (PyObject *printer);
 PyObject *gdbpy_default_visualizer (PyObject *self, PyObject *args);
diff --git a/gdb/python/python-prettyprint.c b/gdb/python/python-prettyprint.c
index 57e517a..5d696c8 100644
--- a/gdb/python/python-prettyprint.c
+++ b/gdb/python/python-prettyprint.c
@@ -121,34 +121,35 @@ find_pretty_printer (PyObject *value)
   
   return function;
 }
-
-/* Pretty-print a single value, via the printer object PRINTER.  If
-   the function returns a string, an xmalloc()d copy is returned.
-   Otherwise, if the function returns a value, a *OUT_VALUE is set to
-   the value, and NULL is returned.  On error, *OUT_VALUE is set to
-   NULL and NULL is returned.  */
-static char *
+/* Pretty-print a single value, via the printer object PRINTER.
+   If the function returns a string, a PyObject containing the string
+   is returned.  Otherwise, if the function returns a value,
+   *OUT_VALUE is set to the value, and NULL is returned.  On error,
+   *OUT_VALUE is set to NULL, and NULL is returned.  */
+static PyObject *
 pretty_print_one_value (PyObject *printer, struct value **out_value)
 {
-  char *output = NULL;
   volatile struct gdb_exception except;
+  PyObject *result = NULL;
 
+  *out_value = NULL;
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      PyObject *result;
-
       result = PyObject_CallMethodObjArgs (printer, gdbpy_to_string_cst, NULL);
       if (result)
 	{
-	  if (gdbpy_is_string (result))
-	    output = python_string_to_host_string (result);
-	  else
-	    *out_value = convert_value_from_python (result);
-	  Py_DECREF (result);
+	  if (! gdbpy_is_string (result))
+	    {
+	      *out_value = convert_value_from_python (result);
+	      if (PyErr_Occurred ())
+		*out_value = NULL;
+	      Py_DECREF (result);
+	      result = NULL;
+	    }
 	}
     }
 
-  return output;
+  return result;
 }
 
 /* Return the display hint for the object printer, PRINTER.  Return
@@ -184,19 +185,28 @@ print_string_repr (PyObject *printer, const char *hint,
 		   const struct language_defn *language,
 		   struct gdbarch *gdbarch)
 {
-  char *output;
   struct value *replacement = NULL;
+  PyObject *py_str = NULL;
 
-  output = pretty_print_one_value (printer, &replacement);
-  if (output)
+  py_str = pretty_print_one_value (printer, &replacement);
+  if (py_str)
     {
-      if (hint && !strcmp (hint, "string"))
-	LA_PRINT_STRING (stream, builtin_type (gdbarch)->builtin_char,
-			 (gdb_byte *) output, strlen (output),
-			 0, options);
+      PyObject *string = python_string_to_target_python_string (py_str);
+      if (string)
+	{
+	  gdb_byte *output = PyString_AsString (string);
+	  int len = PyString_Size (string);
+	  
+	  if (hint && !strcmp (hint, "string"))
+	    LA_PRINT_STRING (stream, builtin_type (gdbarch)->builtin_char,
+			     output, len, 0, options);
+	  else
+	    fputs_filtered (output, stream);
+	  Py_DECREF (string);
+	}
       else
-	fputs_filtered (output, stream);
-      xfree (output);
+	gdbpy_print_stack ();
+      Py_DECREF (py_str);
     }
   else if (replacement)
     common_val_print (replacement, stream, recurse, options, language);
@@ -511,26 +521,30 @@ apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
   return result;
 }
 
+
 /* Apply a pretty-printer for the varobj code.  PRINTER_OBJ is the
    print object.  It must have a 'to_string' method (but this is
    checked by varobj, not here) which takes no arguments and
-   returns a string.  This function returns an xmalloc()d string if
-   the printer returns a string.  The printer may return a replacement
-   value instead; in this case *REPLACEMENT is set to the replacement
-   value, and this function returns NULL.  On error, *REPLACEMENT is
-   set to NULL and this function also returns NULL.  */
-char *
+   returns a string.  The printer will return a value and in the case
+   of a Python string being returned, this function will return a
+   PyObject containing the string.  For any other type, *REPLACEMENT is
+   set to the replacement value and this function returns NULL.  On
+   error, *REPLACEMENT is set to NULL and this function also returns
+   NULL.  */
+PyObject *
 apply_varobj_pretty_printer (PyObject *printer_obj,
 			     struct value **replacement)
 {
-  char *result;
+  int size = 0;
+  PyObject *py_str = NULL;
 
   *replacement = NULL;
-  result = pretty_print_one_value (printer_obj, replacement);
-  if (result == NULL);
+  py_str = pretty_print_one_value (printer_obj, replacement);
+
+  if (*replacement == NULL && py_str == NULL)
     gdbpy_print_stack ();
 
-  return result;
+  return py_str;
 }
 
 /* Find a pretty-printer object for the varobj module.  Returns a new
diff --git a/gdb/python/python-utils.c b/gdb/python/python-utils.c
index 9f6fe07..49c0437 100644
--- a/gdb/python/python-utils.c
+++ b/gdb/python/python-utils.c
@@ -104,6 +104,23 @@ unicode_to_encoded_string (PyObject *unicode_str, const char *charset)
   return result;
 }
 
+/* Returns a PyObject with the contents of the given unicode string
+   object converted to a named charset.  If an error occurs during
+   the conversion, NULL will be returned and a python exception will
+   be set.  */
+static PyObject *
+unicode_to_encoded_python_string (PyObject *unicode_str, const char *charset)
+{
+  PyObject *string;
+
+  /* Translate string to named charset.  */
+  string = PyUnicode_AsEncodedString (unicode_str, charset, NULL);
+  if (string == NULL)
+    return NULL;
+
+  return string;
+}
+
 /* Returns a newly allocated string with the contents of the given unicode
    string object converted to the target's charset.  If an error occurs during
    the conversion, NULL will be returned and a python exception will be set.
@@ -115,6 +132,16 @@ unicode_to_target_string (PyObject *unicode_str)
   return unicode_to_encoded_string (unicode_str, target_charset ());
 }
 
+/* Returns a PyObject with the contents of the given unicode string
+   object converted to the target's charset.  If an error occurs
+   during the conversion, NULL will be returned and a python exception
+   will be set.  */
+PyObject *
+unicode_to_target_python_string (PyObject *unicode_str)
+{
+  return unicode_to_encoded_python_string (unicode_str, target_charset ());
+}
+
 /* Converts a python string (8-bit or unicode) to a target string in
    the target's charset.  Returns NULL on error, with a python exception set.
 
@@ -134,6 +161,24 @@ python_string_to_target_string (PyObject *obj)
   return result;
 }
 
+/* Converts a python string (8-bit or unicode) to a target string in the
+   target's charset.  Returns NULL on error, with a python exception
+   set.  */
+PyObject *
+python_string_to_target_python_string (PyObject *obj)
+{
+  PyObject *str;
+  PyObject *result;
+
+  str = python_string_to_unicode (obj);
+  if (str == NULL)
+    return NULL;
+
+  result = unicode_to_target_python_string (str);
+  Py_DECREF (str);
+  return result;
+}
+
 /* Converts a python string (8-bit or unicode) to a target string in
    the host's charset.  Returns NULL on error, with a python exception set.
 
diff --git a/gdb/python/python-value.c b/gdb/python/python-value.c
index a0bf2db..dd3c919 100644
--- a/gdb/python/python-value.c
+++ b/gdb/python/python-value.c
@@ -189,13 +189,16 @@ valpy_get_type (PyObject *self, void *closure)
   return obj->type;
 }
 
-/* Implementation of gdb.Value.string ([encoding] [, errors]) -> string
-   Return Unicode string with value contents.  If ENCODING is not given,
-   the string is assumed to be encoded in the target's charset.  */
+/* Implementation of gdb.Value.string ([encoding] [, errors]
+   [, length]) -> string.  Return Unicode string with value contents.
+   If ENCODING is not given, the string is assumed to be encoded in
+   the target's charset.  If LENGTH is provided, only fetch string to
+   the length provided.  */
+
 static PyObject *
 valpy_string (PyObject *self, PyObject *args, PyObject *kw)
 {
-  int length, ret = 0;
+  int length = -1, ret = 0;
   gdb_byte *buffer;
   struct value *value = ((value_object *) self)->value;
   volatile struct gdb_exception except;
@@ -204,10 +207,10 @@ valpy_string (PyObject *self, PyObject *args, PyObject *kw)
   const char *errors = NULL;
   const char *user_encoding = NULL;
   const char *la_encoding = NULL;
-  static char *keywords[] = { "encoding", "errors" };
+  static char *keywords[] = { "encoding", "errors", "length" };
 
-  if (!PyArg_ParseTupleAndKeywords (args, kw, "|ss", keywords,
-				    &user_encoding, &errors))
+  if (!PyArg_ParseTupleAndKeywords (args, kw, "|ssi", keywords,
+				    &user_encoding, &errors, &length))
     return NULL;
 
   TRY_CATCH (except, RETURN_MASK_ALL)
@@ -937,7 +940,7 @@ static PyMethodDef value_object_methods[] = {
   { "cast", valpy_cast, METH_VARARGS, "Cast the value to the supplied type." },
   { "dereference", valpy_dereference, METH_NOARGS, "Dereferences the value." },
   { "string", (PyCFunction) valpy_string, METH_VARARGS | METH_KEYWORDS,
-    "string ([encoding] [, errors]) -> string\n\
+    "string ([encoding] [, errors] [, length]) -> string\n\
 Return Unicode string representation of the value." },
   {NULL}  /* Sentinel */
 };