stack.c

早期freebsd实现

/* Print and select stack frames for GDB, the GNU debugger.
   Copyright (C) 1986, 1987, 1989, 1991 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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "value.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "language.h"
#include "frame.h"
#include "gdbcmd.h"
#include "gdbcore.h"
#include "target.h"
#include "breakpoint.h"
#include "demangle.h"

static void
return_command PARAMS ((char *, int));

static void
down_command PARAMS ((char *, int));

static void
down_silently_command PARAMS ((char *, int));

static void
up_command PARAMS ((char *, int));

static void
up_silently_command PARAMS ((char *, int));

static void
frame_command PARAMS ((char *, int));

static void
select_frame_command PARAMS ((char *, int));

static void
args_info PARAMS ((char *, int));

static void
print_frame_arg_vars PARAMS ((FRAME, FILE *));

static void
catch_info PARAMS ((char *, int));

static void
locals_info PARAMS ((char *, int));

static void
print_frame_label_vars PARAMS ((FRAME, int, FILE *));

static void
print_frame_local_vars PARAMS ((FRAME, FILE *));

static int
print_block_frame_labels PARAMS ((struct block *, int *, FILE *));

static int
print_block_frame_locals PARAMS ((struct block *, FRAME, FILE *));

static void
backtrace_command PARAMS ((char *, int));

static FRAME
parse_frame_specification PARAMS ((char *));

static void
frame_info PARAMS ((char *, int));


extern int addressprint;	/* Print addresses, or stay symbolic only? */
extern int info_verbose;	/* Verbosity of symbol reading msgs */
extern int lines_to_list;	/* # of lines "list" command shows by default */

/* The "selected" stack frame is used by default for local and arg access.
   May be zero, for no selected frame.  */

FRAME selected_frame;

/* Level of the selected frame:
   0 for innermost, 1 for its caller, ...
   or -1 for frame specified by address with no defined level.  */

int selected_frame_level;

/* Nonzero means print the full filename and linenumber
   when a frame is printed, and do so in a format programs can parse.  */

int frame_file_full_name = 0;

/* Negative says don't print source line in print_frame_info if
   SOURCE argument is -1.  (Useful for a 'stepi' replacement that
   does "x/i $pc" or when running xgdb.) */

int print_source_at_stop;
static int info_printsource;


/* Print a stack frame briefly.  FRAME should be the frame id
   and LEVEL should be its level in the stack (or -1 for level not defined).
   This prints the level, the function executing, the arguments,
   and the file name and line number.
   If the pc is not at the beginning of the source line,
   the actual pc is printed at the beginning.

   If SOURCE is 1, print the source line as well.
   If SOURCE is -1, print ONLY the source line.  */

void
print_stack_frame (frame, level, source)
     FRAME frame;
     int level;
     int source;
{
  struct frame_info *fi;

  fi = get_frame_info (frame);

  print_frame_info (fi, level, source, 1);
}

void
print_frame_info (fi, level, source, args)
     struct frame_info *fi;
     register int level;
     int source;
     int args;
{
  struct symtab_and_line sal;
  struct symbol *func;
  register char *funname = 0;
  int numargs;

#if 0	/* Symbol reading is fast enough now */
  struct partial_symtab *pst;

  /* Don't give very much information if we haven't readin the
     symbol table yet.  */
  pst = find_pc_psymtab (fi->pc);
  if (pst && !pst->readin)
    {
      /* Abbreviated information.  */
      char *fname;

      if (!find_pc_partial_function (fi->pc, &fname, 0))
	fname = "??";
	
      printf_filtered ("#%-2d ", level);
      if (addressprint)
        printf_filtered ("%s in ", local_hex_string(fi->pc));

      fputs_demangled (fname, stdout, 0);
      fputs_filtered (" (...)\n", stdout);
      
      return;
    }
#endif

#ifdef CORE_NEEDS_RELOCATION
  CORE_NEEDS_RELOCATION(fi->pc);
#endif

  sal = find_pc_line (fi->pc, fi->next_frame);
  func = find_pc_function (fi->pc);
  if (func)
    {
      /* In certain pathological cases, the symtabs give the wrong
	 function (when we are in the first function in a file which
	 is compiled without debugging symbols, the previous function
	 is compiled with debugging symbols, and the "foo.o" symbol
	 that is supposed to tell us where the file with debugging symbols
	 ends has been truncated by ar because it is longer than 15
	 characters).

	 So look in the minimal symbol tables as well, and if it comes
	 up with a larger address for the function use that instead.
	 I don't think this can ever cause any problems; there shouldn't
	 be any minimal symbols in the middle of a function.
	 FIXME:  (Not necessarily true.  What about text labels) */

      struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (fi->pc);
      if (msymbol != NULL
	  && (msymbol -> address
	      > BLOCK_START (SYMBOL_BLOCK_VALUE (func))))
	{
	  /* In this case we have no way of knowing the source file
	     and line number, so don't print them.  */
	  sal.symtab = 0;
	  /* We also don't know anything about the function besides
	     its address and name.  */
	  func = 0;
	  funname = msymbol -> name;
	}
      else
	funname = SYMBOL_NAME (func);
    }
  else
    {
      register struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (fi->pc);
      if (msymbol != NULL)
	funname = msymbol -> name;
    }

  if (source >= 0 || !sal.symtab)
    {
      if (level >= 0)
	printf_filtered ("#%-2d ", level);
      if (addressprint)
	if (fi->pc != sal.pc || !sal.symtab)
	  printf_filtered ("%s in ", local_hex_string(fi->pc));
      fputs_demangled (funname ? funname : "??", stdout, 0);
#ifdef notdef
      /* Steve McCanne doesn't like this. */      
      wrap_here ("   ");
#endif
      fputs_filtered (" (", stdout);
      if (args)
	{
	  FRAME_NUM_ARGS (numargs, fi);
	  print_frame_args (func, fi, numargs, stdout);
	}
      printf_filtered (")");
      if (sal.symtab && sal.symtab->filename)
	{
          wrap_here ("   ");
	  printf_filtered (" at %s:%d", sal.symtab->filename, sal.line);
	}

#ifdef PC_LOAD_SEGMENT
     /* If we couldn't print out function name but if can figure out what
        load segment this pc value is from, at least print out some info
	about its load segment. */
      if (!funname) {
	wrap_here ("  ");
	printf_filtered (" from %s", PC_LOAD_SEGMENT (fi->pc));
      }
#endif
      printf_filtered ("\n");
    }

  if ((source != 0) && sal.symtab)
    {
      if (source > 0 || print_source_at_stop >= 0)
        {
	  int done = 0;
	  int mid_statement = source < 0 && fi->pc != sal.pc;
	  if (frame_file_full_name)
		  done = identify_source_line (sal.symtab, sal.line, mid_statement);
	  if (!done)
	  {
		  if (addressprint && mid_statement)
			  printf_filtered ("%s\t", local_hex_string(fi->pc));
		  print_source_lines (sal.symtab, sal.line, sal.line + 1, 0);
	  }
        }
      current_source_line = max (sal.line - lines_to_list/2, 1);
    }
  if (source != 0)
    set_default_breakpoint (1, fi->pc, sal.symtab, sal.line);

  fflush (stdout);
}

#ifdef FRAME_SPECIFICATION_DYADIC
extern FRAME setup_arbitrary_frame ();
#endif

/*
 * Read a frame specification in whatever the appropriate format is.
 * Call error() if the specification is in any way invalid (i.e.
 * this function never returns NULL).
 */
static FRAME
parse_frame_specification (frame_exp)
     char *frame_exp;
{
  int numargs = 0;
  int arg1, arg2;
  
  if (frame_exp)
    {
      char *addr_string, *p;
      struct cleanup *tmp_cleanup;

      while (*frame_exp == ' ') frame_exp++;
      for (p = frame_exp; *p && *p != ' '; p++)
	;

      if (*frame_exp)
	{
	  numargs = 1;
	  addr_string = savestring(frame_exp, p - frame_exp);

	  {
	    tmp_cleanup = make_cleanup (free, addr_string);
	    arg1 = parse_and_eval_address (addr_string);
	    do_cleanups (tmp_cleanup);
	  }

	  while (*p == ' ') p++;
	  
	  if (*p)
	    {
	      numargs = 2;
	      arg2 = parse_and_eval_address (p);
	    }
	}
    }

  switch (numargs)
    {
    case 0:
      if (selected_frame == NULL)
	error ("No selected frame.");
      return selected_frame;
      /* NOTREACHED */
    case 1:
      {
	int level = arg1;
	FRAME fid = find_relative_frame (get_current_frame (), &level);
	FRAME tfid;

	if (level == 0)
	  /* find_relative_frame was successful */
	  return fid;

	/* If (s)he specifies the frame with an address, he deserves what
	   (s)he gets.  Still, give the highest one that matches.  */

	for (fid = get_current_frame ();
	     fid && FRAME_FP (fid) != arg1;
	     fid = get_prev_frame (fid))
	  ;

	if (fid)
	  while ((tfid = get_prev_frame (fid)) &&
		 (FRAME_FP (tfid) == arg1))
	    fid = tfid;
	  
#ifdef FRAME_SPECIFICATION_DYADIC
	if (!fid)
	  error ("Incorrect number of args in frame specification");

	return fid;
#else
	return create_new_frame (arg1, 0);
#endif
      }
      /* NOTREACHED */
    case 2:
      /* Must be addresses */
#ifndef FRAME_SPECIFICATION_DYADIC
      error ("Incorrect number of args in frame specification");
#else
      return setup_arbitrary_frame (arg1, arg2);
#endif
      /* NOTREACHED */
    }
  fatal ("Internal: Error in parsing in parse_frame_specification");
  /* NOTREACHED */
}

/* FRAME_ARGS_ADDRESS_CORRECT is just like FRAME_ARGS_ADDRESS except
   that if it is unsure about the answer, it returns 0
   instead of guessing (this happens on the VAX and i960, for example).

   On most machines, we never have to guess about the args address,
   so FRAME_ARGS_ADDRESS{,_CORRECT} are the same.  */
#if !defined (FRAME_ARGS_ADDRESS_CORRECT)
#define FRAME_ARGS_ADDRESS_CORRECT FRAME_ARGS_ADDRESS
#endif

/* Print verbosely the selected frame or the frame at address ADDR.
   This means absolutely all information in the frame is printed.  */

static void
frame_info (addr_exp, from_tty)
     char *addr_exp;
     int from_tty;
{
  FRAME frame;
  struct frame_info *fi;
  struct frame_saved_regs fsr;
  struct symtab_and_line sal;
  struct symbol *func;
  struct symtab *s;
  FRAME calling_frame;
  int i, count;
  char *funname = 0;

  if (!target_has_stack)
    error ("No inferior or core file.");

  frame = parse_frame_specification (addr_exp);
  if (!frame)
    error ("Invalid frame specified.");

  fi = get_frame_info (frame);
  sal = find_pc_line (fi->pc, fi->next_frame);
  func = get_frame_function (frame);
  s = find_pc_symtab(fi->pc);
  if (func)
    funname = SYMBOL_NAME (func);
  else
    {
      register struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (fi->pc);
      if (msymbol != NULL)
	funname = msymbol -> name;
    }
  calling_frame = get_prev_frame (frame);

  if (!addr_exp && selected_frame_level >= 0) {
    printf_filtered ("Stack level %d, frame at %s:\n",
		     selected_frame_level, 
		     local_hex_string(FRAME_FP(frame)));
  } else {
    printf_filtered ("Stack frame at %s:\n",
		     local_hex_string(FRAME_FP(frame)));
  }
  printf_filtered (" %s = %s",
		   reg_names[PC_REGNUM], 
		   local_hex_string(fi->pc));

  wrap_here ("   ");