gdb

2009-05-27  Tom Tromey  <tromey@redhat.com>
	    Thiago Jung Bauermann  <bauerman@br.ibm.com>
	    Phil Muldoon  <pmuldoon@redhat.com>
	    Paul Pluzhnikov  <ppluzhnikov@google.com>
	    Vladimir Prus  <vladimir@codesourcery.com>

	* python/python-value.c (value_object_to_value): New function.
	* python/python-internal.h: Include frameobject.h.
	(gdbpy_children_cst, gdbpy_to_string_cst, gdbpy_display_hint_cst):
	Declare.
	(value_object_to_value): Declare.
	* printcmd.c (struct format_data) <raw>: New field.
	(last_format): Default to 0.
	(decode_format): Initialize val.raw.  Handle /r flag.
	(print_command_1): Initialize fmt.raw and opts.raw.
	(output_command): Likewise.
	(x_command): Fix initialization of fmt.format.  Initialize
	fmt.raw.
	(display_command): Initialize fmt.raw.
	(do_one_display): Set opts.raw.
	* python/python.c (gdbpy_to_string_cst, gdbpy_children_cst,
	gdbpy_display_hint_cst): New globals.
	(_initialize_python): Initialize them.  Set gdb.pretty_printers.
	* cp-valprint.c: Include python.h.
	(cp_print_value): Call apply_val_pretty_printer.
	* python/python.h (apply_val_pretty_printer): Declare.
	* stack.c (print_this_frame_argument_p): Remove.
	(print_frame_args): Compute summary flag.  Don't use
	print_this_frame_argument_p.
	* valprint.c: Include python.h.
	(user_print_options): Initialize new fields.
	(scalar_type_p): New function.
	(val_print): Handle 'raw' and 'summary' modes.  Call
	apply_val_pretty_printer.
	(value_print): Handle 'raw' mode.
	* valprint.h (struct value_print_options) <raw, summary>: New
	fields.
	* Makefile.in (SUBDIR_PYTHON_OBS): Add python-prettyprint.o
	(SUBDIR_PYTHON_SRCS): Add python-prettyprint.c.
	(python-prettyprint.o): New target.
	* python/python-prettyprint.c: New file.

gdb/doc

2009-05-27  Tom Tromey  <tromey@redhat.com>
	    Thiago Jung Bauermann  <bauerman@br.ibm.com>
	    Phil Muldoon  <pmuldoon@redhat.com>

	* gdb.texinfo (Objfiles In Python): Reference pretty printing.
	(Pretty Printing): New node.
	(Selecting Pretty-Printers): Likewise.
	(Python API): Update.
	(Output Formats): Document /r format.

gdb/testsuite

2009-05-27  Tom Tromey  <tromey@redhat.com>
	    Thiago Jung Bauermann  <bauerman@br.ibm.com>
	    Phil Muldoon  <pmuldoon@redhat.com>
	    Paul Pluzhnikov  <ppluzhnikov@google.com>

	* gdb.python/python-prettyprint.exp: New file.
	* gdb.python/python-prettyprint.c: New file.
	* gdb.python/python-prettyprint.py: New file.
	* gdb.base/display.exp: print/r is now valid.

5 files changed, 556 insertions, 0 deletions

diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 819867f..983d24d 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -33,6 +33,7 @@
 
 #if HAVE_LIBPYTHON2_4
 #include "python2.4/Python.h"
+#include "python2.4/frameobject.h"
 /* Py_ssize_t is not defined until 2.5.
    Logical type for Py_ssize_t is Py_intptr_t, but that fails in 64-bit
    compilation due to several apparent mistakes in python2.4 API, so we
@@ -40,8 +41,10 @@
 typedef int Py_ssize_t;
 #elif HAVE_LIBPYTHON2_5
 #include "python2.5/Python.h"
+#include "python2.5/frameobject.h"
 #elif HAVE_LIBPYTHON2_6
 #include "python2.6/Python.h"
+#include "python2.6/frameobject.h"
 #else
 #error "Unable to find usable Python.h"
 #endif
@@ -74,6 +77,7 @@ PyObject *objfile_to_objfile_object (struct objfile *);
 
 PyObject *objfpy_get_printers (PyObject *, void *);
 
+struct value *value_object_to_value (PyObject *self);
 struct value *convert_value_from_python (PyObject *obj);
 struct type *type_object_to_type (PyObject *obj);
 
@@ -108,5 +112,8 @@ PyObject *target_string_to_unicode (const gdb_byte *str, int length);
 int gdbpy_is_string (PyObject *obj);
 
 extern PyObject *gdbpy_doc_cst;
+extern PyObject *gdbpy_children_cst;
+extern PyObject *gdbpy_to_string_cst;
+extern PyObject *gdbpy_display_hint_cst;
 
 #endif /* GDB_PYTHON_INTERNAL_H */
diff --git a/gdb/python/python-prettyprint.c b/gdb/python/python-prettyprint.c
new file mode 100644
index 0000000..5be4f36
--- /dev/null
+++ b/gdb/python/python-prettyprint.c
@@ -0,0 +1,524 @@
+/* Python pretty-printing
+
+   Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "exceptions.h"
+#include "objfiles.h"
+#include "symtab.h"
+#include "language.h"
+#include "valprint.h"
+#include "python.h"
+#include "python-internal.h"
+
+#ifdef HAVE_PYTHON
+
+/* 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
+   will return None.  On error, it will set the Python error and
+   return NULL.  */
+static PyObject *
+search_pp_list (PyObject *list, PyObject *value)
+{
+  Py_ssize_t pp_list_size, list_index;
+  PyObject *function, *printer = NULL;
+
+  pp_list_size = PyList_Size (list);
+  for (list_index = 0; list_index < pp_list_size; list_index++)
+    {
+      function = PyList_GetItem (list, list_index);
+      if (! function)
+	return NULL;
+
+      printer = PyObject_CallFunctionObjArgs (function, value, NULL);
+      if (! printer)
+	return NULL;
+      else if (printer != Py_None)
+	return printer;
+
+      Py_DECREF (printer);
+    }
+
+  Py_RETURN_NONE;
+}
+
+/* Find the pretty-printing constructor function for VALUE.  If no
+   pretty-printer exists, return None.  If one exists, return a new
+   reference.  On error, set the Python error and return NULL.  */
+static PyObject *
+find_pretty_printer (PyObject *value)
+{
+  PyObject *pp_list = NULL;
+  PyObject *function = NULL;
+  struct objfile *obj;
+  volatile struct gdb_exception except;
+
+  /* Look at the pretty-printer dictionary for each objfile.  */
+  ALL_OBJFILES (obj)
+  {
+    PyObject *objf = objfile_to_objfile_object (obj);
+    if (!objf)
+      {
+	/* Ignore the error and continue.  */
+	PyErr_Clear ();
+	continue;
+      }
+
+    pp_list = objfpy_get_printers (objf, NULL);
+    function = search_pp_list (pp_list, value);
+
+    /* If there is an error in any objfile list, abort the search and
+       exit.  */
+    if (! function)
+      {
+	Py_XDECREF (pp_list);
+	return NULL;
+      }
+
+    if (function != Py_None)
+      goto done;
+    
+    Py_DECREF (function);
+    Py_XDECREF (pp_list);
+  }
+
+  pp_list = NULL;
+  /* Fetch the global pretty printer dictionary.  */
+  if (! PyObject_HasAttrString (gdb_module, "pretty_printers"))
+    {
+      function = Py_None;
+      Py_INCREF (function);
+      goto done;
+    }
+  pp_list = PyObject_GetAttrString (gdb_module, "pretty_printers");
+  if (! pp_list)
+    goto done;
+  if (! PyList_Check (pp_list))
+    goto done;
+
+  function = search_pp_list (pp_list, value);
+
+ done:
+  Py_XDECREF (pp_list);
+  
+  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_one_value (PyObject *printer, struct value **out_value)
+{
+  char *output = NULL;
+  volatile struct gdb_exception except;
+
+  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);
+	}
+    }
+
+  return output;
+}
+
+/* Return the display hint for the object printer, PRINTER.  Return
+   NULL if there is no display_hint method, or if the method did not
+   return a string.  On error, print stack trace and return NULL.  On
+   success, return an xmalloc()d string.  */
+char *
+gdbpy_get_display_hint (PyObject *printer)
+{
+  PyObject *hint;
+  char *result = NULL;
+
+  if (! PyObject_HasAttr (printer, gdbpy_display_hint_cst))
+    return NULL;
+
+  hint = PyObject_CallMethodObjArgs (printer, gdbpy_display_hint_cst, NULL);
+  if (gdbpy_is_string (hint))
+    result = python_string_to_host_string (hint);
+  if (hint)
+    Py_DECREF (hint);
+  else
+    gdbpy_print_stack ();
+
+  return result;
+}
+
+/* Helper for apply_val_pretty_printer which calls to_string and
+   formats the result.  */
+static void
+print_string_repr (PyObject *printer, const char *hint,
+		   struct ui_file *stream, int recurse,
+		   const struct value_print_options *options,
+		   const struct language_defn *language)
+{
+  char *output;
+  struct value *replacement = NULL;
+
+  output = pretty_print_one_value (printer, &replacement);
+  if (output)
+    {
+      if (hint && !strcmp (hint, "string"))
+	LA_PRINT_STRING (stream, builtin_type (current_gdbarch)->builtin_char,
+			 (gdb_byte *) output, strlen (output),
+			 0, options);
+      else
+	fputs_filtered (output, stream);
+      xfree (output);
+    }
+  else if (replacement)
+    common_val_print (replacement, stream, recurse, options, language);
+  else
+    gdbpy_print_stack ();
+}
+
+static void
+py_restore_tstate (void *p)
+{
+  PyFrameObject *frame = p;
+  PyThreadState *tstate = PyThreadState_GET ();
+  tstate->frame = frame;
+}
+
+/* Create a dummy PyFrameObject, needed to work around
+   a Python-2.4 bug with generators.  */
+static PyObject *
+push_dummy_python_frame ()
+{
+  PyObject *empty_string, *null_tuple, *globals;
+  PyCodeObject *code;
+  PyFrameObject *frame;
+  PyThreadState *tstate;
+
+  empty_string = PyString_FromString ("");
+  if (!empty_string)
+    return NULL;
+
+  null_tuple = PyTuple_New (0);
+  if (!null_tuple)
+    {
+      Py_DECREF (empty_string);
+      return NULL;
+    }
+
+  code = PyCode_New (0,			/* argcount */
+		     0,			/* nlocals */
+		     0,			/* stacksize */
+		     0,			/* flags */
+		     empty_string,	/* code */
+		     null_tuple,	/* consts */
+		     null_tuple,	/* names */
+		     null_tuple,	/* varnames */
+#if PYTHON_API_VERSION >= 1010
+		     null_tuple,	/* freevars */
+		     null_tuple,	/* cellvars */
+#endif
+		     empty_string,	/* filename */
+		     empty_string,	/* name */
+		     1,			/* firstlineno */
+		     empty_string	/* lnotab */
+		    );
+
+  Py_DECREF (empty_string);
+  Py_DECREF (null_tuple);
+
+  if (!code)
+    return NULL;
+
+  globals = PyDict_New ();
+  if (!globals)
+    {
+      Py_DECREF (code);
+      return NULL;
+    }
+
+  tstate = PyThreadState_GET ();
+
+  frame = PyFrame_New (tstate, code, globals, NULL);
+
+  Py_DECREF (globals);
+  Py_DECREF (code);
+
+  if (!frame)
+    return NULL;
+
+  tstate->frame = frame;
+  make_cleanup (py_restore_tstate, frame->f_back);
+  return (PyObject *) frame;
+}
+
+/* Helper for apply_val_pretty_printer that formats children of the
+   printer, if any exist.  */
+static void
+print_children (PyObject *printer, const char *hint,
+		struct ui_file *stream, int recurse,
+		const struct value_print_options *options,
+		const struct language_defn *language)
+{
+  int is_map, is_array, done_flag, pretty;
+  unsigned int i;
+  PyObject *children, *iter, *frame;
+  struct cleanup *cleanups;
+
+  if (! PyObject_HasAttr (printer, gdbpy_children_cst))
+    return;
+
+  /* If we are printing a map or an array, we want some special
+     formatting.  */
+  is_map = hint && ! strcmp (hint, "map");
+  is_array = hint && ! strcmp (hint, "array");
+
+  children = PyObject_CallMethodObjArgs (printer, gdbpy_children_cst,
+					 NULL);
+  if (! children)
+    {
+      gdbpy_print_stack ();
+      return;
+    }
+
+  cleanups = make_cleanup_py_decref (children);
+
+  iter = PyObject_GetIter (children);
+  if (!iter)
+    {
+      gdbpy_print_stack ();
+      goto done;
+    }
+  make_cleanup_py_decref (iter);
+
+  /* Use the prettyprint_arrays option if we are printing an array,
+     and the pretty option otherwise.  */
+  pretty = is_array ? options->prettyprint_arrays : options->pretty;
+
+  /* Manufacture a dummy Python frame to work around Python 2.4 bug,
+     where it insists on having a non-NULL tstate->frame when
+     a generator is called.  */
+  frame = push_dummy_python_frame ();
+  if (!frame)
+    {
+      gdbpy_print_stack ();
+      goto done;
+    }
+  make_cleanup_py_decref (frame);
+
+  done_flag = 0;
+  for (i = 0; i < options->print_max; ++i)
+    {
+      PyObject *py_v, *item = PyIter_Next (iter);
+      char *name;
+      struct cleanup *inner_cleanup;
+
+      if (! item)
+	{
+	  if (PyErr_Occurred ())
+	    gdbpy_print_stack ();
+	  /* Set a flag so we can know whether we printed all the
+	     available elements.  */
+	  else	  
+	    done_flag = 1;
+	  break;
+	}
+
+      if (! PyArg_ParseTuple (item, "sO", &name, &py_v))
+	{
+	  gdbpy_print_stack ();
+	  Py_DECREF (item);
+	  continue;
+	}
+      inner_cleanup = make_cleanup_py_decref (item);
+
+      /* Print initial "{".  For other elements, there are three
+	 cases:
+	 1. Maps.  Print a "," after each value element.
+	 2. Arrays.  Always print a ",".
+	 3. Other.  Always print a ",".  */
+      if (i == 0)
+	fputs_filtered (" = {", stream);
+      else if (! is_map || i % 2 == 0)
+	fputs_filtered (pretty ? "," : ", ", stream);
+
+      /* In summary mode, we just want to print "= {...}" if there is
+	 a value.  */
+      if (options->summary)
+	{
+	  /* This increment tricks the post-loop logic to print what
+	     we want.  */
+	  ++i;
+	  /* Likewise.  */
+	  pretty = 0;
+	  break;
+	}
+
+      if (! is_map || i % 2 == 0)
+	{
+	  if (pretty)
+	    {
+	      fputs_filtered ("\n", stream);
+	      print_spaces_filtered (2 + 2 * recurse, stream);
+	    }
+	  else
+	    wrap_here (n_spaces (2 + 2 *recurse));
+	}
+
+      if (is_map && i % 2 == 0)
+	fputs_filtered ("[", stream);
+      else if (is_array)
+	{
+	  /* We print the index, not whatever the child method
+	     returned as the name.  */
+	  if (options->print_array_indexes)
+	    fprintf_filtered (stream, "[%d] = ", i);
+	}
+      else if (! is_map)
+	{
+	  fputs_filtered (name, stream);
+	  fputs_filtered (" = ", stream);
+	}
+
+      if (gdbpy_is_string (py_v))
+	{
+	  char *text = python_string_to_host_string (py_v);
+	  if (! text)
+	    gdbpy_print_stack ();
+	  else
+	    {
+	      fputs_filtered (text, stream);
+	      xfree (text);
+	    }
+	}
+      else
+	{
+	  struct value *value = convert_value_from_python (py_v);
+
+	  if (value == NULL)
+	    {
+	      gdbpy_print_stack ();
+	      error (_("Error while executing Python code."));
+	    }
+	  else
+	    common_val_print (value, stream, recurse + 1, options, language);
+	}
+
+      if (is_map && i % 2 == 0)
+	fputs_filtered ("] = ", stream);
+
+      do_cleanups (inner_cleanup);
+    }
+
+  if (i)
+    {
+      if (!done_flag)
+	{
+	  if (pretty)
+	    {
+	      fputs_filtered ("\n", stream);
+	      print_spaces_filtered (2 + 2 * recurse, stream);
+	    }
+	  fputs_filtered ("...", stream);
+	}
+      if (pretty)
+	{
+	  fputs_filtered ("\n", stream);
+	  print_spaces_filtered (2 * recurse, stream);
+	}
+      fputs_filtered ("}", stream);
+    }
+
+ done:
+  do_cleanups (cleanups);
+}
+
+int
+apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
+			  int embedded_offset, CORE_ADDR address,
+			  struct ui_file *stream, int recurse,
+			  const struct value_print_options *options,
+			  const struct language_defn *language)
+{
+  PyObject *printer = NULL;
+  PyObject *val_obj = NULL;
+  struct value *value;
+  char *hint = NULL;
+  struct cleanup *cleanups;
+  int result = 0;
+  PyGILState_STATE state;
+
+  state = PyGILState_Ensure ();
+  cleanups = make_cleanup_py_restore_gil (&state);
+
+  /* Instantiate the printer.  */
+  if (valaddr)
+    valaddr += embedded_offset;
+  value = value_from_contents_and_address (type, valaddr, address);
+
+  val_obj = value_to_value_object (value);
+  if (! val_obj)
+    goto done;
+  
+  /* Find the constructor.  */
+  printer = find_pretty_printer (val_obj);
+  Py_DECREF (val_obj);
+  make_cleanup_py_decref (printer);
+  if (! printer || printer == Py_None)
+    goto done;
+
+  /* If we are printing a map, we want some special formatting.  */
+  hint = gdbpy_get_display_hint (printer);
+  make_cleanup (free_current_contents, &hint);
+
+  /* Print the section */
+  print_string_repr (printer, hint, stream, recurse, options, language);
+  print_children (printer, hint, stream, recurse, options, language);
+  result = 1;
+
+
+ done:
+  if (PyErr_Occurred ())
+    gdbpy_print_stack ();
+  do_cleanups (cleanups);
+  return result;
+}
+
+#else /* HAVE_PYTHON */
+
+int
+apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
+			  int embedded_offset, CORE_ADDR address,
+			  struct ui_file *stream, int format,
+			  int deref_ref, int recurse,
+			  enum val_prettyprint pretty,
+			  const struct language_defn *language)
+{
+  return 0;
+}
+
+#endif /* HAVE_PYTHON */
diff --git a/gdb/python/python-value.c b/gdb/python/python-value.c
index 76f5cde..46af318 100644
--- a/gdb/python/python-value.c
+++ b/gdb/python/python-value.c
@@ -805,6 +805,17 @@ value_to_value_object (struct value *val)
   return (PyObject *) val_obj;
 }
 
+/* Returns value structure corresponding to the given value object.  */
+struct value *
+value_object_to_value (PyObject *self)
+{
+  value_object *real;
+  if (! PyObject_TypeCheck (self, &value_object_type))
+    return NULL;
+  real = (value_object *) self;
+  return real->value;
+}
+
 /* Try to convert a Python value to a gdb value.  If the value cannot
    be converted, set a Python exception and return NULL.  */
 
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 701a931..19098cc 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -52,6 +52,10 @@ static PyMethodDef GdbMethods[];
 
 PyObject *gdb_module;
 
+/* Some string constants we may wish to use.  */
+PyObject *gdbpy_to_string_cst;
+PyObject *gdbpy_children_cst;
+PyObject *gdbpy_display_hint_cst;
 PyObject *gdbpy_doc_cst;
 
 /* Given a command_line, return a command string suitable for passing
@@ -556,9 +560,13 @@ Enables or disables auto-loading of Python code when an object is opened."),
   gdbpy_initialize_objfile ();
 
   PyRun_SimpleString ("import gdb");
+  PyRun_SimpleString ("gdb.pretty_printers = []");
 
   observer_attach_new_objfile (gdbpy_new_objfile);
 
+  gdbpy_to_string_cst = PyString_FromString ("to_string");
+  gdbpy_children_cst = PyString_FromString ("children");
+  gdbpy_display_hint_cst = PyString_FromString ("display_hint");
   gdbpy_doc_cst = PyString_FromString ("__doc__");
 
   /* Create a couple objects which are used for Python's stdout and
diff --git a/gdb/python/python.h b/gdb/python/python.h
index e63c447..33b0437 100644
--- a/gdb/python/python.h
+++ b/gdb/python/python.h
@@ -26,4 +26,10 @@ extern struct value *values_in_python;
 
 void eval_python_from_control_command (struct command_line *);
 
+int apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
+			      int embedded_offset, CORE_ADDR address,
+			      struct ui_file *stream, int recurse,
+			      const struct value_print_options *options,
+			      const struct language_defn *language);
+
 #endif /* GDB_PYTHON_H */