gdb

	* varobj.c (value_get_print_value): Rearrange.  Pass stream to
	apply_varobj_pretty_printer.
	* c-lang.c: Include exceptions.h.
	(c_get_string): Throw MEMORY_ERROR when appropriate.
	* python/py-prettyprint.c (enum string_repr_result): New.
	(print_stack_unless_memory_error): New function.
	(print_string_repr): Change return type.  Use
	print_stack_unless_memory_error.
	(print_children): Use print_stack_unless_memory_error.
	(apply_val_pretty_printer): Update.  Don't print children if
	string representation threw an exception.
	(apply_varobj_pretty_printer): Add 'stream' argument.  Use
	print_stack_unless_memory_error.
	* python/python.c (gdbpy_gdb_error, gdbpy_gdb_memory_error): New
	globals.
	(_initialize_python): Initialize them.
	* python/python-internal.h (GDB_PY_HANDLE_EXCEPTION): Use
	gdbpy_convert_exception.
	(GDB_PY_SET_HANDLE_EXCEPTION): Likewise.
	(gdbpy_gdb_error, gdbpy_gdb_memory_error): Declare.
	(gdbpy_convert_exception): Declare.
	(apply_varobj_pretty_printer): Update.
	* python/py-utils.c (gdbpy_convert_exception): New function.
gdb/doc
	* gdb.texinfo (Basic Python): Update.  Add xref.
	(Exception Handling): Document new exception classes.
	(Types In Python): Update.
	(Frames In Python): Update.
gdb/testsuite
	* gdb.python/py-prettyprint.c (main): Add new 'ns2' local.
	* gdb.python/py-prettyprint.exp (run_lang_tests): Add test for
	MemoryError.
	* gdb.python/python.exp (gdb_py_test_multiple): Update exception
	type.
	* gdb.python/py-value.exp (test_value_in_inferior): Add test for
	MemoryError.
	(test_subscript_regression): Update exception type.

4 files changed, 112 insertions, 28 deletions

diff --git a/gdb/python/py-prettyprint.c b/gdb/python/py-prettyprint.c
index afe2b40..7be1409 100644
--- a/gdb/python/py-prettyprint.c
+++ b/gdb/python/py-prettyprint.c
@@ -29,6 +29,18 @@
 #ifdef HAVE_PYTHON
 #include "python-internal.h"
 
+/* Return type of print_string_repr.  */
+
+enum string_repr_result
+  {
+    /* The string method returned None.  */
+    string_repr_none,
+    /* The string method had an error.  */
+    string_repr_error,
+    /* Everything ok.  */
+    string_repr_ok
+  };
+
 /* Helper function for find_pretty_printer which iterates over a list,
    calls each function and inspects output.  This will return a
    printer object if one recognizes VALUE.  If no printer is found, it
@@ -256,12 +268,40 @@ gdbpy_get_display_hint (PyObject *printer)
   return result;
 }
 
+/* A wrapper for gdbpy_print_stack that ignores MemoryError.  */
+
+static void
+print_stack_unless_memory_error (struct ui_file *stream)
+{
+  if (PyErr_ExceptionMatches (gdbpy_gdb_memory_error))
+    {
+      struct cleanup *cleanup;
+      PyObject *type, *value, *trace;
+      char *msg;
+
+      PyErr_Fetch (&type, &value, &trace);
+      cleanup = make_cleanup_py_decref (type);
+      make_cleanup_py_decref (value);
+      make_cleanup_py_decref (trace);
+
+      msg = gdbpy_exception_to_string (type, value);
+      make_cleanup (xfree, msg);
+
+      if (msg == NULL || *msg == '\0')
+	fprintf_filtered (stream, _("<error reading variable"));
+      else
+	fprintf_filtered (stream, _("<error reading variable: %s>"), msg);
+
+      do_cleanups (cleanup);
+    }
+  else
+    gdbpy_print_stack ();
+}
+
 /* Helper for apply_val_pretty_printer which calls to_string and
-   formats the result.  If the value returnd is Py_None, nothing is
-   printed and the function returns a 1; in all other cases data is
-   printed as given by the pretty printer and the function returns 0.
-*/
-static int
+   formats the result.  */
+
+static enum string_repr_result
 print_string_repr (PyObject *printer, const char *hint,
 		   struct ui_file *stream, int recurse,
 		   const struct value_print_options *options,
@@ -270,7 +310,7 @@ print_string_repr (PyObject *printer, const char *hint,
 {
   struct value *replacement = NULL;
   PyObject *py_str = NULL;
-  int is_py_none = 0;
+  enum string_repr_result result = string_repr_ok;
 
   py_str = pretty_print_one_value (printer, &replacement);
   if (py_str)
@@ -278,7 +318,7 @@ print_string_repr (PyObject *printer, const char *hint,
       struct cleanup *cleanup = make_cleanup_py_decref (py_str);
 
       if (py_str == Py_None)
-	is_py_none = 1;
+	result = string_repr_none;
       else if (gdbpy_is_lazy_string (py_str))
 	{
 	  CORE_ADDR addr;
@@ -316,7 +356,10 @@ print_string_repr (PyObject *printer, const char *hint,
 		fputs_filtered (output, stream);
 	    }
 	  else
-	    gdbpy_print_stack ();
+	    {
+	      result = string_repr_error;
+	      print_stack_unless_memory_error (stream);
+	    }
 	}
 
       do_cleanups (cleanup);
@@ -329,9 +372,12 @@ print_string_repr (PyObject *printer, const char *hint,
       common_val_print (replacement, stream, recurse, &opts, language);
     }
   else
-    gdbpy_print_stack ();
+    {
+      result = string_repr_error;
+      print_stack_unless_memory_error (stream);
+    }
 
-  return is_py_none;
+  return result;
 }
 
 static void
@@ -437,7 +483,7 @@ print_children (PyObject *printer, const char *hint,
 					 NULL);
   if (! children)
     {
-      gdbpy_print_stack ();
+      print_stack_unless_memory_error (stream);
       return;
     }
 
@@ -446,7 +492,7 @@ print_children (PyObject *printer, const char *hint,
   iter = PyObject_GetIter (children);
   if (!iter)
     {
-      gdbpy_print_stack ();
+      print_stack_unless_memory_error (stream);
       goto done;
     }
   make_cleanup_py_decref (iter);
@@ -476,7 +522,7 @@ print_children (PyObject *printer, const char *hint,
       if (! item)
 	{
 	  if (PyErr_Occurred ())
-	    gdbpy_print_stack ();
+	    print_stack_unless_memory_error (stream);
 	  /* Set a flag so we can know whether we printed all the
 	     available elements.  */
 	  else	  
@@ -631,7 +677,7 @@ apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
   char *hint = NULL;
   struct cleanup *cleanups;
   int result = 0;
-  int is_py_none = 0;
+  enum string_repr_result print_result;
   cleanups = ensure_python_env (gdbarch, language);
 
   /* Instantiate the printer.  */
@@ -666,17 +712,18 @@ apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
   make_cleanup (free_current_contents, &hint);
 
   /* Print the section */
-  is_py_none = print_string_repr (printer, hint, stream, recurse,
-				  options, language, gdbarch);
-  print_children (printer, hint, stream, recurse, options, language,
-		  is_py_none);
+  print_result = print_string_repr (printer, hint, stream, recurse,
+				    options, language, gdbarch);
+  if (print_result != string_repr_error)
+    print_children (printer, hint, stream, recurse, options, language,
+		    print_result == string_repr_none);
 
   result = 1;
 
 
  done:
   if (PyErr_Occurred ())
-    gdbpy_print_stack ();
+    print_stack_unless_memory_error (stream);
   do_cleanups (cleanups);
   return result;
 }
@@ -693,7 +740,8 @@ apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
    NULL.  */
 PyObject *
 apply_varobj_pretty_printer (PyObject *printer_obj,
-			     struct value **replacement)
+			     struct value **replacement,
+			     struct ui_file *stream)
 {
   PyObject *py_str = NULL;
 
@@ -701,7 +749,7 @@ apply_varobj_pretty_printer (PyObject *printer_obj,
   py_str = pretty_print_one_value (printer_obj, replacement);
 
   if (*replacement == NULL && py_str == NULL)
-    gdbpy_print_stack ();
+    print_stack_unless_memory_error (stream);
 
   return py_str;
 }
diff --git a/gdb/python/py-utils.c b/gdb/python/py-utils.c
index 90609fa..2f0aac4 100644
--- a/gdb/python/py-utils.c
+++ b/gdb/python/py-utils.c
@@ -274,6 +274,25 @@ gdbpy_exception_to_string (PyObject *ptype, PyObject *pvalue)
   return str;
 }
 
+/* Convert a GDB exception to the appropriate Python exception.
+   
+   This sets the Python error indicator, and returns NULL.  */
+
+PyObject *
+gdbpy_convert_exception (struct gdb_exception exception)
+{
+  PyObject *exc_class;
+
+  if (exception.reason == RETURN_QUIT)
+    exc_class = PyExc_KeyboardInterrupt;
+  else if (exception.error == MEMORY_ERROR)
+    exc_class = gdbpy_gdb_memory_error;
+  else
+    exc_class = gdbpy_gdb_error;
+
+  return PyErr_Format (exc_class, "%s", exception.message);
+}
+
 /* Converts OBJ to a CORE_ADDR value.
 
    Returns 1 on success or 0 on failure, with a Python exception set.  This
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 67de622..30d7533 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -80,6 +80,8 @@ typedef int Py_ssize_t;
 /* Also needed to parse enum var_types. */
 #include "command.h"
 
+#include "exceptions.h"
+
 struct block;
 struct value;
 struct language_defn;
@@ -179,9 +181,7 @@ extern const struct language_defn *python_language;
 #define GDB_PY_HANDLE_EXCEPTION(Exception)				\
     do {								\
       if (Exception.reason < 0)						\
-	return PyErr_Format (Exception.reason == RETURN_QUIT		\
-			     ? PyExc_KeyboardInterrupt : PyExc_RuntimeError, \
-			     "%s", Exception.message);			\
+	return gdbpy_convert_exception (Exception);			\
     } while (0)
 
 /* Use this after a TRY_EXCEPT to throw the appropriate Python
@@ -190,9 +190,7 @@ extern const struct language_defn *python_language;
     do {								\
       if (Exception.reason < 0)						\
         {								\
-	  PyErr_Format (Exception.reason == RETURN_QUIT			\
-			? PyExc_KeyboardInterrupt : PyExc_RuntimeError, \
-			"%s", Exception.message);			\
+	  gdbpy_convert_exception (Exception);				\
 	  return -1;							\
 	}								\
     } while (0)
@@ -222,7 +220,8 @@ int gdbpy_is_value_object (PyObject *obj);
 /* Note that these are declared here, and not in python.h with the
    other pretty-printer functions, because they refer to PyObject.  */
 PyObject *apply_varobj_pretty_printer (PyObject *print_obj,
-				       struct value **replacement);
+				       struct value **replacement,
+				       struct ui_file *stream);
 PyObject *gdbpy_get_varobj_pretty_printer (struct value *value);
 char *gdbpy_get_display_hint (PyObject *printer);
 PyObject *gdbpy_default_visualizer (PyObject *self, PyObject *args);
@@ -233,8 +232,13 @@ extern PyObject *gdbpy_to_string_cst;
 extern PyObject *gdbpy_display_hint_cst;
 extern PyObject *gdbpy_enabled_cst;
 
+/* Exception types.  */
+extern PyObject *gdbpy_gdb_error;
+extern PyObject *gdbpy_gdb_memory_error;
 extern PyObject *gdbpy_gdberror_exc;
 
+extern PyObject *gdbpy_convert_exception (struct gdb_exception);
+
 int get_addr_from_python (PyObject *obj, CORE_ADDR *addr);
 
 #endif /* GDB_PYTHON_INTERNAL_H */
diff --git a/gdb/python/python.c b/gdb/python/python.c
index d4f8c3d..d009be9 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -66,6 +66,12 @@ PyObject *gdbpy_enabled_cst;
 /* The GdbError exception.  */
 PyObject *gdbpy_gdberror_exc;
 
+/* The `gdb.error' base class.  */
+PyObject *gdbpy_gdb_error;
+
+/* The `gdb.MemoryError' exception.  */
+PyObject *gdbpy_gdb_memory_error;
+
 /* Architecture and language to be used in callbacks from
    the Python interpreter.  */
 struct gdbarch *python_gdbarch;
@@ -967,6 +973,13 @@ Enables or disables printing of Python stack traces."),
     xfree (gdb_pythondir);
   }
 
+  gdbpy_gdb_error = PyErr_NewException ("gdb.error", PyExc_RuntimeError, NULL);
+  PyModule_AddObject (gdb_module, "error", gdbpy_gdb_error);
+
+  gdbpy_gdb_memory_error = PyErr_NewException ("gdb.MemoryError",
+					       gdbpy_gdb_error, NULL);
+  PyModule_AddObject (gdb_module, "MemoryError", gdbpy_gdb_memory_error);
+
   gdbpy_gdberror_exc = PyErr_NewException ("gdb.GdbError", NULL, NULL);
   PyModule_AddObject (gdb_module, "GdbError", gdbpy_gdberror_exc);