Remove unnecessary casts of NULL

[deliverable/binutils-gdb.git] / gdb / tui / tui-stack.c

/* TUI display locator.

   Copyright (C) 1998-2019 Free Software Foundation, Inc.

   Contributed by Hewlett-Packard 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 "symtab.h"
#include "breakpoint.h"
#include "frame.h"
#include "command.h"
#include "inferior.h"
#include "target.h"
#include "top.h"
#include "gdb-demangle.h"
#include "source.h"
#include "tui/tui.h"
#include "tui/tui-data.h"
#include "tui/tui-stack.h"
#include "tui/tui-wingeneral.h"
#include "tui/tui-source.h"
#include "tui/tui-winsource.h"
#include "tui/tui-file.h"

#include "gdb_curses.h"

/* Get a printable name for the function at the address.
   The symbol name is demangled if demangling is turned on.
   Returns a pointer to a static area holding the result.  */
static char *tui_get_function_from_frame (struct frame_info *fi);

/* Set the full_name portion of the locator.  */
static void tui_set_locator_fullname (const char *fullname);

/* Update the locator, with the provided arguments.  */
static int tui_set_locator_info (struct gdbarch *gdbarch,
                                 const char *fullname,
                                 const char *procname,
                                 int lineno, CORE_ADDR addr);

static void tui_update_command (const char *, int);
\f

/* Create the status line to display as much information as we can on
   this single line: target name, process number, current function,
   current line, current PC, SingleKey mode.  */
static char*
tui_make_status_line (struct tui_locator_element *loc)
{
  char *string;
  char line_buf[50], *pname;
  char *buf;
  int status_size;
  int i, proc_width;
  const char *pid_name;
  int target_width;
  int pid_width;
  int line_width;

  std::string pid_name_holder;
  if (inferior_ptid == null_ptid)
    pid_name = "No process";
  else
    {
      pid_name_holder = target_pid_to_str (inferior_ptid);
      pid_name = pid_name_holder.c_str ();
    }

  target_width = strlen (target_shortname);
  if (target_width > MAX_TARGET_WIDTH)
    target_width = MAX_TARGET_WIDTH;

  pid_width = strlen (pid_name);
  if (pid_width > MAX_PID_WIDTH)
    pid_width = MAX_PID_WIDTH;

  status_size = tui_term_width ();
  string = (char *) xmalloc (status_size + 1);
  buf = (char*) alloca (status_size + 1);

  /* Translate line number and obtain its size.  */
  if (loc->line_no > 0)
    xsnprintf (line_buf, sizeof (line_buf), "%d", loc->line_no);
  else
    strcpy (line_buf, "??");
  line_width = strlen (line_buf);
  if (line_width < MIN_LINE_WIDTH)
    line_width = MIN_LINE_WIDTH;

  /* Translate PC address.  */
  string_file pc_out;

  fputs_filtered (loc->gdbarch? paddress (loc->gdbarch, loc->addr) : "??",
                  &pc_out);

  const char *pc_buf = pc_out.c_str ();
  int pc_width = pc_out.size ();

  /* First determine the amount of proc name width we have available.
     The +1 are for a space separator between fields.
     The -1 are to take into account the \0 counted by sizeof.  */
  proc_width = (status_size
                - (target_width + 1)
                - (pid_width + 1)
                - (sizeof (PROC_PREFIX) - 1 + 1)
                - (sizeof (LINE_PREFIX) - 1 + line_width + 1)
                - (sizeof (PC_PREFIX) - 1 + pc_width + 1)
                - (tui_current_key_mode == TUI_SINGLE_KEY_MODE
                   ? (sizeof (SINGLE_KEY) - 1 + 1)
                   : 0));

  /* If there is no room to print the function name, try by removing
     some fields.  */
  if (proc_width < MIN_PROC_WIDTH)
    {
      proc_width += target_width + 1;
      target_width = 0;
      if (proc_width < MIN_PROC_WIDTH)
        {
          proc_width += pid_width + 1;
          pid_width = 0;
          if (proc_width <= MIN_PROC_WIDTH)
            {
              proc_width += pc_width + sizeof (PC_PREFIX) - 1 + 1;
              pc_width = 0;
              if (proc_width < 0)
                {
                  proc_width += line_width + sizeof (LINE_PREFIX) - 1 + 1;
                  line_width = 0;
                  if (proc_width < 0)
                    proc_width = 0;
                }
            }
        }
    }

  /* Now convert elements to string form.  */
  pname = loc->proc_name;

  /* Now create the locator line from the string version of the
     elements.  We could use sprintf() here but that wouldn't ensure
     that we don't overrun the size of the allocated buffer.
     strcat_to_buf() will.  */
  *string = (char) 0;

  if (target_width > 0)
    {
      sprintf (buf, "%*.*s ",
               -target_width, target_width, target_shortname);
      strcat_to_buf (string, status_size, buf);
    }
  if (pid_width > 0)
    {
      sprintf (buf, "%*.*s ",
               -pid_width, pid_width, pid_name);
      strcat_to_buf (string, status_size, buf);
    }
  
  /* Show whether we are in SingleKey mode.  */
  if (tui_current_key_mode == TUI_SINGLE_KEY_MODE)
    {
      strcat_to_buf (string, status_size, SINGLE_KEY);
      strcat_to_buf (string, status_size, " ");
    }

  /* Procedure/class name.  */
  if (proc_width > 0)
    {
      if (strlen (pname) > proc_width)
        sprintf (buf, "%s%*.*s* ", PROC_PREFIX,
                 1 - proc_width, proc_width - 1, pname);
      else
        sprintf (buf, "%s%*.*s ", PROC_PREFIX,
                 -proc_width, proc_width, pname);
      strcat_to_buf (string, status_size, buf);
    }

  if (line_width > 0)
    {
      sprintf (buf, "%s%*.*s ", LINE_PREFIX,
               -line_width, line_width, line_buf);
      strcat_to_buf (string, status_size, buf);
    }
  if (pc_width > 0)
    {
      strcat_to_buf (string, status_size, PC_PREFIX);
      strcat_to_buf (string, status_size, pc_buf);
    }
  
  
  for (i = strlen (string); i < status_size; i++)
    string[i] = ' ';
  string[status_size] = (char) 0;

  return string;
}

/* Get a printable name for the function at the address.  The symbol
   name is demangled if demangling is turned on.  Returns a pointer to
   a static area holding the result.  */
static char*
tui_get_function_from_frame (struct frame_info *fi)
{
  static char name[256];
  string_file stream;

  print_address_symbolic (get_frame_arch (fi), get_frame_pc (fi),
                          &stream, demangle, "");

  /* Use simple heuristics to isolate the function name.  The symbol
     can be demangled and we can have function parameters.  Remove
     them because the status line is too short to display them.  */
  const char *d = stream.c_str ();
  if (*d == '<')
    d++;
  strncpy (name, d, sizeof (name) - 1);
  name[sizeof (name) - 1] = 0;

  char *p = strchr (name, '(');
  if (!p)
    p = strchr (name, '>');
  if (p)
    *p = 0;
  p = strchr (name, '+');
  if (p)
    *p = 0;
  return name;
}

void
tui_show_locator_content (void)
{
  char *string;
  struct tui_gen_win_info *locator;

  locator = tui_locator_win_info_ptr ();

  if (locator != NULL && locator->handle != NULL)
    {
      struct tui_win_element *element;

      element = locator->content[0];

      string = tui_make_status_line (&element->which_element.locator);
      wmove (locator->handle, 0, 0);
      /* We ignore the return value from wstandout and wstandend, casting
         them to void in order to avoid a compiler warning.  The warning
         itself was introduced by a patch to ncurses 5.7 dated 2009-08-29,
         changing these macro to expand to code that causes the compiler
         to generate an unused-value warning.  */
      (void) wstandout (locator->handle);
      waddstr (locator->handle, string);
      wclrtoeol (locator->handle);
      (void) wstandend (locator->handle);
      tui_refresh_win (locator);
      wmove (locator->handle, 0, 0);
      xfree (string);
      locator->content_in_use = TRUE;
    }
}


/* Set the filename portion of the locator.  */
static void
tui_set_locator_fullname (const char *fullname)
{
  struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
  struct tui_locator_element *element;

  if (locator->content[0] == NULL)
    {
      tui_set_locator_info (NULL, fullname, NULL, 0, 0);
      return;
    }

  element = &locator->content[0]->which_element.locator;
  element->full_name[0] = 0;
  strcat_to_buf (element->full_name, MAX_LOCATOR_ELEMENT_LEN, fullname);
}

/* Update the locator, with the provided arguments.

   Returns 1 if any of the locator's fields were actually changed,
   and 0 otherwise.  */

static int
tui_set_locator_info (struct gdbarch *gdbarch,
                      const char *fullname,
                      const char *procname, 
                      int lineno,
                      CORE_ADDR addr)
{
  struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
  struct tui_locator_element *element;
  int locator_changed_p = 0;

  /* Allocate the locator content if necessary.  */
  if (locator->content_size <= 0)
    {
      locator->content = tui_alloc_content (1, LOCATOR_WIN);
      locator->content_size = 1;
      locator_changed_p = 1;
    }

  if (procname == NULL)
    procname = "";

  if (fullname == NULL)
    fullname = "";

  element = &locator->content[0]->which_element.locator;

  locator_changed_p |= strncmp (element->proc_name, procname,
                                MAX_LOCATOR_ELEMENT_LEN) != 0;
  locator_changed_p |= lineno != element->line_no;
  locator_changed_p |= addr != element->addr;
  locator_changed_p |= gdbarch != element->gdbarch;
  locator_changed_p |= strncmp (element->full_name, fullname,
                                MAX_LOCATOR_ELEMENT_LEN) != 0;

  element->proc_name[0] = (char) 0;
  strcat_to_buf (element->proc_name, MAX_LOCATOR_ELEMENT_LEN, procname);
  element->line_no = lineno;
  element->addr = addr;
  element->gdbarch = gdbarch;
  tui_set_locator_fullname (fullname);

  return locator_changed_p;
}

/* Update only the full_name portion of the locator.  */
void
tui_update_locator_fullname (const char *fullname)
{
  tui_set_locator_fullname (fullname);
  tui_show_locator_content ();
}

/* Function to print the frame information for the TUI.  The windows are
   refreshed only if frame information has changed since the last refresh.

   Return 1 if frame information has changed (and windows subsequently
   refreshed), 0 otherwise.  */

int
tui_show_frame_info (struct frame_info *fi)
{
  struct tui_win_info *win_info;
  int locator_changed_p;

  if (fi)
    {
      int start_line, i;
      CORE_ADDR low;
      struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
      int source_already_displayed;
      CORE_ADDR pc;

      symtab_and_line sal = find_frame_sal (fi);

      source_already_displayed = sal.symtab != 0
        && tui_source_is_displayed (symtab_to_fullname (sal.symtab));

      if (get_frame_pc_if_available (fi, &pc))
        locator_changed_p
          = tui_set_locator_info (get_frame_arch (fi),
                                  (sal.symtab == 0
                                   ? "??" : symtab_to_fullname (sal.symtab)),
                                  tui_get_function_from_frame (fi),
                                  sal.line,
                                  pc);
      else
        locator_changed_p
          = tui_set_locator_info (get_frame_arch (fi),
                                  "??", _("<unavailable>"), sal.line, 0);

      /* If the locator information has not changed, then frame information has
         not changed.  If frame information has not changed, then the windows'
         contents will not change.  So don't bother refreshing the windows.  */
      if (!locator_changed_p)
        return 0;

      tui_show_locator_content ();
      start_line = 0;
      for (i = 0; i < (tui_source_windows ())->count; i++)
        {
          union tui_which_element *item;

          win_info = (tui_source_windows ())->list[i];

          item = &locator->content[0]->which_element;
          if (win_info == TUI_SRC_WIN)
            {
              start_line = (item->locator.line_no -
                           (win_info->generic.viewport_height / 2)) + 1;
              if (start_line <= 0)
                start_line = 1;
            }
          else
            {
              if (find_pc_partial_function (get_frame_pc (fi),
                                            NULL, &low, NULL) == 0)
                {
                  /* There is no symbol available for current PC.  There is no
                     safe way how to "disassemble backwards".  */
                  low = get_frame_pc (fi);
                }
              else
                low = tui_get_low_disassembly_address (get_frame_arch (fi),
                                                       low, get_frame_pc (fi));
            }

          if (win_info == TUI_SRC_WIN)
            {
              struct tui_line_or_address l;

              l.loa = LOA_LINE;
              l.u.line_no = start_line;
              if (!(source_already_displayed
                    && tui_line_is_displayed (item->locator.line_no,
                                              win_info, TRUE)))
                tui_update_source_window (win_info, get_frame_arch (fi),
                                          sal.symtab, l, TRUE);
              else
                {
                  l.u.line_no = item->locator.line_no;
                  tui_set_is_exec_point_at (l, win_info);
                }
            }
          else
            {
              if (win_info == TUI_DISASM_WIN)
                {
                  struct tui_line_or_address a;

                  a.loa = LOA_ADDRESS;
                  a.u.addr = low;
                  if (!tui_addr_is_displayed (item->locator.addr,
                                              win_info, TRUE))
                    tui_update_source_window (win_info, get_frame_arch (fi),
                                              sal.symtab, a, TRUE);
                  else
                    {
                      a.u.addr = item->locator.addr;
                      tui_set_is_exec_point_at (a, win_info);
                    }
                }
            }
          tui_update_exec_info (win_info);
        }

      return 1;
    }
  else
    {
      locator_changed_p
        = tui_set_locator_info (NULL, NULL, NULL, 0, (CORE_ADDR) 0);

      if (!locator_changed_p)
        return 0;

      tui_show_locator_content ();
      for (int i = 0; i < (tui_source_windows ())->count; i++)
        {
          win_info = (tui_source_windows ())->list[i];
          tui_clear_source_content (win_info, EMPTY_SOURCE_PROMPT);
          tui_update_exec_info (win_info);
        }

      return 1;
    }
}

/* Function to initialize gdb commands, for tui window stack
   manipulation.  */

void
_initialize_tui_stack (void)
{
  add_com ("update", class_tui, tui_update_command,
           _("Update the source window and locator to "
             "display the current execution point."));
}

/* Command to update the display with the current execution point.  */
static void
tui_update_command (const char *arg, int from_tty)
{
  execute_command ("frame 0", from_tty);
}