/home/stan/gdb/src/gdb/mi/mi-cmd-stack.c

Go to the documentation of this file.

/* MI Command Set - stack commands.
   Copyright (C) 2000-2013 Free Software Foundation, Inc.
   Contributed by Cygnus Solutions (a Red Hat company).

   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 "target.h"
#include "frame.h"
#include "value.h"
#include "mi-cmds.h"
#include "ui-out.h"
#include "symtab.h"
#include "block.h"
#include "stack.h"
#include "dictionary.h"
#include "gdb_string.h"
#include "language.h"
#include "valprint.h"
#include "exceptions.h"
#include "utils.h"
#include "mi-getopt.h"
#include "python/python.h"
#include <ctype.h>
#include "mi-parse.h"

enum what_to_list { locals, arguments, all };

static void list_args_or_locals (enum what_to_list what,
                                 enum print_values values,
                                 struct frame_info *fi,
                                 int skip_unavailable);

/* True if we want to allow Python-based frame filters.  */
static int frame_filters = 0;

void
mi_cmd_enable_frame_filters (char *command, char **argv, int argc)
{
  if (argc != 0)
    error (_("-enable-frame-filters: no arguments allowed"));
  frame_filters = 1;
}

/* Print a list of the stack frames.  Args can be none, in which case
   we want to print the whole backtrace, or a pair of numbers
   specifying the frame numbers at which to start and stop the
   display.  If the two numbers are equal, a single frame will be
   displayed.  */

void
mi_cmd_stack_list_frames (char *command, char **argv, int argc)
{
  int frame_low;
  int frame_high;
  int i;
  struct cleanup *cleanup_stack;
  struct frame_info *fi;
  enum py_bt_status result = PY_BT_ERROR;
  int raw_arg = 0;
  int oind = 0;
  enum opt
    {
      NO_FRAME_FILTERS
    };
  static const struct mi_opt opts[] =
    {
      {"-no-frame-filters", NO_FRAME_FILTERS, 0},
      { 0, 0, 0 }
    };

  /* Parse arguments.  In this instance we are just looking for
     --no-frame-filters.  */
  while (1)
    {
      char *oarg;
      int opt = mi_getopt ("-stack-list-frames", argc, argv,
                           opts, &oind, &oarg);
      if (opt < 0)
        break;
      switch ((enum opt) opt)
        {
        case NO_FRAME_FILTERS:
          raw_arg = oind;
          break;
        }
    }

  /* After the last option is parsed, there should either be low -
     high range, or no further arguments.  */
  if ((argc - oind != 0) && (argc - oind != 2))
    error (_("-stack-list-frames: Usage: [--no-frame-filters] [FRAME_LOW FRAME_HIGH]"));

  /* If there is a range, set it.  */
  if (argc - oind == 2)
    {
      frame_low = atoi (argv[0 + oind]);
      frame_high = atoi (argv[1 + oind]);
    }
  else
    {
      /* Called with no arguments, it means we want the whole
         backtrace.  */
      frame_low = -1;
      frame_high = -1;
    }

  /* Let's position fi on the frame at which to start the
     display. Could be the innermost frame if the whole stack needs
     displaying, or if frame_low is 0.  */
  for (i = 0, fi = get_current_frame ();
       fi && i < frame_low;
       i++, fi = get_prev_frame (fi));

  if (fi == NULL)
    error (_("-stack-list-frames: Not enough frames in stack."));

  cleanup_stack = make_cleanup_ui_out_list_begin_end (current_uiout, "stack");

  if (! raw_arg && frame_filters)
    {
      int flags = PRINT_LEVEL | PRINT_FRAME_INFO;
      int py_frame_low = frame_low;

      /* We cannot pass -1 to frame_low, as that would signify a
      relative backtrace from the tail of the stack.  So, in the case
      of frame_low == -1, assign and increment it.  */
      if (py_frame_low == -1)
        py_frame_low++;

      result = apply_frame_filter (get_current_frame (), flags,
                                   NO_VALUES,  current_uiout,
                                   py_frame_low, frame_high);
    }

  /* Run the inbuilt backtrace if there are no filters registered, or
     if "--no-frame-filters" has been specified from the command.  */
  if (! frame_filters || raw_arg  || result == PY_BT_NO_FILTERS)
    {
      /* Now let's print the frames up to frame_high, or until there are
         frames in the stack.  */
      for (;
           fi && (i <= frame_high || frame_high == -1);
           i++, fi = get_prev_frame (fi))
        {
          QUIT;
          /* Print the location and the address always, even for level 0.
             If args is 0, don't print the arguments.  */
          print_frame_info (fi, 1, LOC_AND_ADDRESS, 0 /* args */, 0);
        }
    }

  do_cleanups (cleanup_stack);
}

void
mi_cmd_stack_info_depth (char *command, char **argv, int argc)
{
  int frame_high;
  int i;
  struct frame_info *fi;

  if (argc > 1)
    error (_("-stack-info-depth: Usage: [MAX_DEPTH]"));

  if (argc == 1)
    frame_high = atoi (argv[0]);
  else
    /* Called with no arguments, it means we want the real depth of
       the stack.  */
    frame_high = -1;

  for (i = 0, fi = get_current_frame ();
       fi && (i < frame_high || frame_high == -1);
       i++, fi = get_prev_frame (fi))
    QUIT;

  ui_out_field_int (current_uiout, "depth", i);
}

/* Print a list of the locals for the current frame.  With argument of
   0, print only the names, with argument of 1 print also the
   values.  */

void
mi_cmd_stack_list_locals (char *command, char **argv, int argc)
{
  struct frame_info *frame;
  int raw_arg = 0;
  enum py_bt_status result = PY_BT_ERROR;
  int print_value;
  int oind = 0;
  int skip_unavailable = 0;
  int i;

  if (argc > 1)
    {
      int i;
      enum opt
      {
        NO_FRAME_FILTERS,
        SKIP_UNAVAILABLE,
      };
      static const struct mi_opt opts[] =
        {
          {"-no-frame-filters", NO_FRAME_FILTERS, 0},
          {"-skip-unavailable", SKIP_UNAVAILABLE, 0},
          { 0, 0, 0 }
        };

      while (1)
        {
          char *oarg;
          /* Don't parse 'print-values' as an option.  */
          int opt = mi_getopt ("-stack-list-locals", argc - 1, argv,
                               opts, &oind, &oarg);

          if (opt < 0)
            break;
          switch ((enum opt) opt)
            {
            case NO_FRAME_FILTERS:
              raw_arg = oind;
            case SKIP_UNAVAILABLE:
              skip_unavailable = 1;
              break;
            }
        }
    }

  /* After the last option is parsed, there should be only
     'print-values'.  */
  if (argc - oind != 1)
    error (_("-stack-list-locals: Usage: [--no-frame-filters] "
             "[--skip-unavailable] PRINT_VALUES"));

  frame = get_selected_frame (NULL);
  print_value = mi_parse_print_values (argv[oind]);

   if (! raw_arg && frame_filters)
     {
       int flags = PRINT_LEVEL | PRINT_LOCALS;

       result = apply_frame_filter (frame, flags, print_value,
                                    current_uiout, 0, 0);
     }

   /* Run the inbuilt backtrace if there are no filters registered, or
      if "--no-frame-filters" has been specified from the command.  */
   if (! frame_filters || raw_arg  || result == PY_BT_NO_FILTERS)
     {
       list_args_or_locals (locals, print_value, frame,
                            skip_unavailable);
     }
}

/* Print a list of the arguments for the current frame.  With argument
   of 0, print only the names, with argument of 1 print also the
   values.  */

void
mi_cmd_stack_list_args (char *command, char **argv, int argc)
{
  int frame_low;
  int frame_high;
  int i;
  struct frame_info *fi;
  struct cleanup *cleanup_stack_args;
  enum print_values print_values;
  struct ui_out *uiout = current_uiout;
  int raw_arg = 0;
  int oind = 0;
  int skip_unavailable = 0;
  enum py_bt_status result = PY_BT_ERROR;
  enum opt
  {
    NO_FRAME_FILTERS,
    SKIP_UNAVAILABLE,
  };
  static const struct mi_opt opts[] =
    {
      {"-no-frame-filters", NO_FRAME_FILTERS, 0},
      {"-skip-unavailable", SKIP_UNAVAILABLE, 0},
      { 0, 0, 0 }
    };

  while (1)
    {
      char *oarg;
      int opt = mi_getopt_allow_unknown ("-stack-list-args", argc, argv,
                                         opts, &oind, &oarg);

      if (opt < 0)
        break;
      switch ((enum opt) opt)
        {
        case NO_FRAME_FILTERS:
          raw_arg = oind;
          break;
        case SKIP_UNAVAILABLE:
          skip_unavailable = 1;
          break;
        }
    }

  if (argc - oind != 1 && argc - oind != 3)
    error (_("-stack-list-arguments: Usage: "   \
             "[--no-frame-filters] [--skip-unavailable] "
             "PRINT_VALUES [FRAME_LOW FRAME_HIGH]"));

  if (argc - oind == 3)
    {
      frame_low = atoi (argv[1 + oind]);
      frame_high = atoi (argv[2 + oind]);
    }
  else
    {
      /* Called with no arguments, it means we want args for the whole
         backtrace.  */
      frame_low = -1;
      frame_high = -1;
    }

  print_values = mi_parse_print_values (argv[oind]);

  /* Let's position fi on the frame at which to start the
     display. Could be the innermost frame if the whole stack needs
     displaying, or if frame_low is 0.  */
  for (i = 0, fi = get_current_frame ();
       fi && i < frame_low;
       i++, fi = get_prev_frame (fi));

  if (fi == NULL)
    error (_("-stack-list-arguments: Not enough frames in stack."));

  cleanup_stack_args
    = make_cleanup_ui_out_list_begin_end (uiout, "stack-args");

  if (! raw_arg && frame_filters)
    {
      int flags = PRINT_LEVEL | PRINT_ARGS;
      int py_frame_low = frame_low;

      /* We cannot pass -1 to frame_low, as that would signify a
      relative backtrace from the tail of the stack.  So, in the case
      of frame_low == -1, assign and increment it.  */
      if (py_frame_low == -1)
        py_frame_low++;

      result = apply_frame_filter (get_current_frame (), flags,
                                   print_values, current_uiout,
                                   py_frame_low, frame_high);
    }

     /* Run the inbuilt backtrace if there are no filters registered, or
      if "--no-frame-filters" has been specified from the command.  */
   if (! frame_filters || raw_arg  || result == PY_BT_NO_FILTERS)
     {
      /* Now let's print the frames up to frame_high, or until there are
         frames in the stack.  */
      for (;
           fi && (i <= frame_high || frame_high == -1);
           i++, fi = get_prev_frame (fi))
        {
          struct cleanup *cleanup_frame;

          QUIT;
          cleanup_frame = make_cleanup_ui_out_tuple_begin_end (uiout, "frame");
          ui_out_field_int (uiout, "level", i);
          list_args_or_locals (arguments, print_values, fi, skip_unavailable);
          do_cleanups (cleanup_frame);
        }
    }
  do_cleanups (cleanup_stack_args);
}

/* Print a list of the local variables (including arguments) for the 
   current frame.  ARGC must be 1 and ARGV[0] specify if only the names,
   or both names and values of the variables must be printed.  See 
   parse_print_value for possible values.  */

void
mi_cmd_stack_list_variables (char *command, char **argv, int argc)
{
  struct frame_info *frame;
  int raw_arg = 0;
  enum py_bt_status result = PY_BT_ERROR;
  int print_value;
  int oind = 0;
  int skip_unavailable = 0;

  if (argc > 1)
    {
      int i;
      enum opt
      {
        NO_FRAME_FILTERS,
        SKIP_UNAVAILABLE,
      };
      static const struct mi_opt opts[] =
        {
          {"-no-frame-filters", NO_FRAME_FILTERS, 0},
          {"-skip-unavailable", SKIP_UNAVAILABLE, 0},
          { 0, 0, 0 }
        };

      while (1)
        {
          char *oarg;
          /* Don't parse 'print-values' as an option.  */
          int opt = mi_getopt ("-stack-list-variables", argc - 1,
                               argv, opts, &oind, &oarg);
          if (opt < 0)
            break;
          switch ((enum opt) opt)
            {
            case NO_FRAME_FILTERS:
              raw_arg = oind;
              break;
            case SKIP_UNAVAILABLE:
              skip_unavailable = 1;
              break;
            }
        }
    }

  /* After the last option is parsed, there should be only
     'print-values'.  */
  if (argc - oind != 1)
    error (_("-stack-list-variables: Usage: [--no-frame-filters] " \
             "[--skip-unavailable] PRINT_VALUES"));

   frame = get_selected_frame (NULL);
   print_value = mi_parse_print_values (argv[oind]);

   if (! raw_arg && frame_filters)
     {
       int flags = PRINT_LEVEL | PRINT_ARGS | PRINT_LOCALS;

       result = apply_frame_filter (frame, flags, print_value,
                                    current_uiout, 0, 0);
     }

   /* Run the inbuilt backtrace if there are no filters registered, or
      if "--no-frame-filters" has been specified from the command.  */
   if (! frame_filters || raw_arg  || result == PY_BT_NO_FILTERS)
     {
       list_args_or_locals (all, print_value, frame,
                            skip_unavailable);
     }
}

/* Print single local or argument.  ARG must be already read in.  For
   WHAT and VALUES see list_args_or_locals.

   Errors are printed as if they would be the parameter value.  Use
   zeroed ARG iff it should not be printed according to VALUES.  If
   SKIP_UNAVAILABLE is true, only print ARG if it is available.  */

static void
list_arg_or_local (const struct frame_arg *arg, enum what_to_list what,
                   enum print_values values, int skip_unavailable)
{
  struct cleanup *old_chain;
  struct ui_out *uiout = current_uiout;
  struct ui_file *stb;

  gdb_assert (!arg->val || !arg->error);
  gdb_assert ((values == PRINT_NO_VALUES && arg->val == NULL
               && arg->error == NULL)
              || values == PRINT_SIMPLE_VALUES
              || (values == PRINT_ALL_VALUES
                  && (arg->val != NULL || arg->error != NULL)));
  gdb_assert (arg->entry_kind == print_entry_values_no
              || (arg->entry_kind == print_entry_values_only
                  && (arg->val || arg->error)));

  if (skip_unavailable && arg->val != NULL
      && (value_entirely_unavailable (arg->val)
          /* A scalar object that does not have all bits available is
             also considered unavailable, because all bits contribute
             to its representation.  */
          || (val_print_scalar_type_p (value_type (arg->val))
              && !value_bytes_available (arg->val,
                                         value_embedded_offset (arg->val),
                                         TYPE_LENGTH (value_type (arg->val))))))
    return;

  stb = mem_fileopen ();
  old_chain = make_cleanup_ui_file_delete (stb);

  if (values != PRINT_NO_VALUES || what == all)
    make_cleanup_ui_out_tuple_begin_end (uiout, NULL);

  fputs_filtered (SYMBOL_PRINT_NAME (arg->sym), stb);
  if (arg->entry_kind == print_entry_values_only)
    fputs_filtered ("@entry", stb);
  ui_out_field_stream (uiout, "name", stb);

  if (what == all && SYMBOL_IS_ARGUMENT (arg->sym))
    ui_out_field_int (uiout, "arg", 1);

  if (values == PRINT_SIMPLE_VALUES)
    {
      check_typedef (arg->sym->type);
      type_print (arg->sym->type, "", stb, -1);
      ui_out_field_stream (uiout, "type", stb);
    }

  if (arg->val || arg->error)
    {
      volatile struct gdb_exception except;

      if (arg->error)
        except.message = arg->error;
      else
        {
          /* TRY_CATCH has two statements, wrap it in a block.  */

          TRY_CATCH (except, RETURN_MASK_ERROR)
            {
              struct value_print_options opts;

              get_no_prettyformat_print_options (&opts);
              opts.deref_ref = 1;
              common_val_print (arg->val, stb, 0, &opts,
                                language_def (SYMBOL_LANGUAGE (arg->sym)));
            }
        }
      if (except.message)
        fprintf_filtered (stb, _("<error reading variable: %s>"),
                          except.message);
      ui_out_field_stream (uiout, "value", stb);
    }

  do_cleanups (old_chain);
}

/* Print a list of the objects for the frame FI in a certain form,
   which is determined by VALUES.  The objects can be locals,
   arguments or both, which is determined by WHAT.  If SKIP_UNAVAILABLE
   is true, only print the arguments or local variables whose values
   are available.  */

static void
list_args_or_locals (enum what_to_list what, enum print_values values,
                     struct frame_info *fi, int skip_unavailable)
{
  struct block *block;
  struct symbol *sym;
  struct block_iterator iter;
  struct cleanup *cleanup_list;
  struct type *type;
  char *name_of_result;
  struct ui_out *uiout = current_uiout;

  block = get_frame_block (fi, 0);

  switch (what)
    {
    case locals:
      name_of_result = "locals";
      break;
    case arguments:
      name_of_result = "args";
      break;
    case all:
      name_of_result = "variables";
      break;
    default:
      internal_error (__FILE__, __LINE__,
                      "unexpected what_to_list: %d", (int) what);
    }

  cleanup_list = make_cleanup_ui_out_list_begin_end (uiout, name_of_result);

  while (block != 0)
    {
      ALL_BLOCK_SYMBOLS (block, iter, sym)
        {
          int print_me = 0;

          switch (SYMBOL_CLASS (sym))
            {
            default:
            case LOC_UNDEF:     /* catches errors        */
            case LOC_CONST:     /* constant              */
            case LOC_TYPEDEF:   /* local typedef         */
            case LOC_LABEL:     /* local label           */
            case LOC_BLOCK:     /* local function        */
            case LOC_CONST_BYTES:       /* loc. byte seq.        */
            case LOC_UNRESOLVED:        /* unresolved static     */
            case LOC_OPTIMIZED_OUT:     /* optimized out         */
              print_me = 0;
              break;

            case LOC_ARG:       /* argument              */
            case LOC_REF_ARG:   /* reference arg         */
            case LOC_REGPARM_ADDR:      /* indirect register arg */
            case LOC_LOCAL:     /* stack local           */
            case LOC_STATIC:    /* static                */
            case LOC_REGISTER:  /* register              */
            case LOC_COMPUTED:  /* computed location     */
              if (what == all)
                print_me = 1;
              else if (what == locals)
                print_me = !SYMBOL_IS_ARGUMENT (sym);
              else
                print_me = SYMBOL_IS_ARGUMENT (sym);
              break;
            }
          if (print_me)
            {
              struct symbol *sym2;
              struct frame_arg arg, entryarg;

              if (SYMBOL_IS_ARGUMENT (sym))
                sym2 = lookup_symbol (SYMBOL_LINKAGE_NAME (sym),
                                      block, VAR_DOMAIN,
                                      NULL);
              else
                sym2 = sym;
              gdb_assert (sym2 != NULL);

              memset (&arg, 0, sizeof (arg));
              arg.sym = sym2;
              arg.entry_kind = print_entry_values_no;
              memset (&entryarg, 0, sizeof (entryarg));
              entryarg.sym = sym2;
              entryarg.entry_kind = print_entry_values_no;

              switch (values)
                {
                case PRINT_SIMPLE_VALUES:
                  type = check_typedef (sym2->type);
                  if (TYPE_CODE (type) != TYPE_CODE_ARRAY
                      && TYPE_CODE (type) != TYPE_CODE_STRUCT
                      && TYPE_CODE (type) != TYPE_CODE_UNION)
                    {
                case PRINT_ALL_VALUES:
                  if (SYMBOL_IS_ARGUMENT (sym))
                    read_frame_arg (sym2, fi, &arg, &entryarg);
                  else
                    read_frame_local (sym2, fi, &arg);
                    }
                  break;
                }

              if (arg.entry_kind != print_entry_values_only)
                list_arg_or_local (&arg, what, values, skip_unavailable);
              if (entryarg.entry_kind != print_entry_values_no)
                list_arg_or_local (&entryarg, what, values, skip_unavailable);
              xfree (arg.error);
              xfree (entryarg.error);
            }
        }

      if (BLOCK_FUNCTION (block))
        break;
      else
        block = BLOCK_SUPERBLOCK (block);
    }
  do_cleanups (cleanup_list);
}

void
mi_cmd_stack_select_frame (char *command, char **argv, int argc)
{
  if (argc == 0 || argc > 1)
    error (_("-stack-select-frame: Usage: FRAME_SPEC"));

  select_frame_command (argv[0], 1 /* not used */ );
}

void
mi_cmd_stack_info_frame (char *command, char **argv, int argc)
{
  if (argc > 0)
    error (_("-stack-info-frame: No arguments allowed"));

  print_frame_info (get_selected_frame (NULL), 1, LOC_AND_ADDRESS, 0, 1);
}