gdb/common/common-utils.c

/* Shared general utility routines for GDB, the GNU debugger.

   Copyright (C) 1986-2018 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 "common-defs.h"
#include "common-utils.h"
#include "host-defs.h"
#include <sys/stat.h>
#include <ctype.h>

/* The xmalloc() (libiberty.h) family of memory management routines.

   These are like the ISO-C malloc() family except that they implement
   consistent semantics and guard against typical memory management
   problems.  */

/* NOTE: These are declared using PTR to ensure consistency with
   "libiberty.h".  xfree() is GDB local.  */

PTR                            /* ARI: PTR */
xmalloc (size_t size)
{
  void *val;

  /* See libiberty/xmalloc.c.  This function need's to match that's
     semantics.  It never returns NULL.  */
  if (size == 0)
    size = 1;

  val = malloc (size);         /* ARI: malloc */
  if (val == NULL)
    malloc_failure (size);

  return val;
}

PTR                              /* ARI: PTR */
xrealloc (PTR ptr, size_t size)          /* ARI: PTR */
{
  void *val;

  /* See libiberty/xmalloc.c.  This function need's to match that's
     semantics.  It never returns NULL.  */
  if (size == 0)
    size = 1;

  if (ptr != NULL)
    val = realloc (ptr, size);	/* ARI: realloc */
  else
    val = malloc (size);	        /* ARI: malloc */
  if (val == NULL)
    malloc_failure (size);

  return val;
}

PTR                            /* ARI: PTR */           
xcalloc (size_t number, size_t size)
{
  void *mem;

  /* See libiberty/xmalloc.c.  This function need's to match that's
     semantics.  It never returns NULL.  */
  if (number == 0 || size == 0)
    {
      number = 1;
      size = 1;
    }

  mem = calloc (number, size);      /* ARI: xcalloc */
  if (mem == NULL)
    malloc_failure (number * size);

  return mem;
}

void *
xzalloc (size_t size)
{
  return xcalloc (1, size);
}

void
xmalloc_failed (size_t size)
{
  malloc_failure (size);
}

/* Like asprintf/vasprintf but get an internal_error if the call
   fails. */

char *
xstrprintf (const char *format, ...)
{
  char *ret;
  va_list args;

  va_start (args, format);
  ret = xstrvprintf (format, args);
  va_end (args);
  return ret;
}

char *
xstrvprintf (const char *format, va_list ap)
{
  char *ret = NULL;
  int status = vasprintf (&ret, format, ap);

  /* NULL is returned when there was a memory allocation problem, or
     any other error (for instance, a bad format string).  A negative
     status (the printed length) with a non-NULL buffer should never
     happen, but just to be sure.  */
  if (ret == NULL || status < 0)
    internal_error (__FILE__, __LINE__, _("vasprintf call failed"));
  return ret;
}

int
xsnprintf (char *str, size_t size, const char *format, ...)
{
  va_list args;
  int ret;

  va_start (args, format);
  ret = vsnprintf (str, size, format, args);
  gdb_assert (ret < size);
  va_end (args);

  return ret;
}

/* See documentation in common-utils.h.  */

std::string
string_printf (const char* fmt, ...)
{
  va_list vp;
  int size;

  va_start (vp, fmt);
  size = vsnprintf (NULL, 0, fmt, vp);
  va_end (vp);

  std::string str (size, '\0');

  /* C++11 and later guarantee std::string uses contiguous memory and
     always includes the terminating '\0'.  */
  va_start (vp, fmt);
  vsprintf (&str[0], fmt, vp);
  va_end (vp);

  return str;
}

/* See documentation in common-utils.h.  */

std::string
string_vprintf (const char* fmt, va_list args)
{
  va_list vp;
  size_t size;

  va_copy (vp, args);
  size = vsnprintf (NULL, 0, fmt, vp);
  va_end (vp);

  std::string str (size, '\0');

  /* C++11 and later guarantee std::string uses contiguous memory and
     always includes the terminating '\0'.  */
  vsprintf (&str[0], fmt, args);

  return str;
}


/* See documentation in common-utils.h.  */

void
string_appendf (std::string &str, const char *fmt, ...)
{
  va_list vp;

  va_start (vp, fmt);
  string_vappendf (str, fmt, vp);
  va_end (vp);
}


/* See documentation in common-utils.h.  */

void
string_vappendf (std::string &str, const char *fmt, va_list args)
{
  va_list vp;
  int grow_size;

  va_copy (vp, args);
  grow_size = vsnprintf (NULL, 0, fmt, vp);
  va_end (vp);

  size_t curr_size = str.size ();
  str.resize (curr_size + grow_size);

  /* C++11 and later guarantee std::string uses contiguous memory and
     always includes the terminating '\0'.  */
  vsprintf (&str[curr_size], fmt, args);
}

char *
savestring (const char *ptr, size_t len)
{
  char *p = (char *) xmalloc (len + 1);

  memcpy (p, ptr, len);
  p[len] = 0;
  return p;
}

/* The bit offset of the highest byte in a ULONGEST, for overflow
   checking.  */

#define HIGH_BYTE_POSN ((sizeof (ULONGEST) - 1) * HOST_CHAR_BIT)

/* True (non-zero) iff DIGIT is a valid digit in radix BASE,
   where 2 <= BASE <= 36.  */

static int
is_digit_in_base (unsigned char digit, int base)
{
  if (!isalnum (digit))
    return 0;
  if (base <= 10)
    return (isdigit (digit) && digit < base + '0');
  else
    return (isdigit (digit) || tolower (digit) < base - 10 + 'a');
}

static int
digit_to_int (unsigned char c)
{
  if (isdigit (c))
    return c - '0';
  else
    return tolower (c) - 'a' + 10;
}

/* As for strtoul, but for ULONGEST results.  */

ULONGEST
strtoulst (const char *num, const char **trailer, int base)
{
  unsigned int high_part;
  ULONGEST result;
  int minus = 0;
  int i = 0;

  /* Skip leading whitespace.  */
  while (isspace (num[i]))
    i++;

  /* Handle prefixes.  */
  if (num[i] == '+')
    i++;
  else if (num[i] == '-')
    {
      minus = 1;
      i++;
    }

  if (base == 0 || base == 16)
    {
      if (num[i] == '0' && (num[i + 1] == 'x' || num[i + 1] == 'X'))
	{
	  i += 2;
	  if (base == 0)
	    base = 16;
	}
    }

  if (base == 0 && num[i] == '0')
    base = 8;

  if (base == 0)
    base = 10;

  if (base < 2 || base > 36)
    {
      errno = EINVAL;
      return 0;
    }

  result = high_part = 0;
  for (; is_digit_in_base (num[i], base); i += 1)
    {
      result = result * base + digit_to_int (num[i]);
      high_part = high_part * base + (unsigned int) (result >> HIGH_BYTE_POSN);
      result &= ((ULONGEST) 1 << HIGH_BYTE_POSN) - 1;
      if (high_part > 0xff)
	{
	  errno = ERANGE;
	  result = ~ (ULONGEST) 0;
	  high_part = 0;
	  minus = 0;
	  break;
	}
    }

  if (trailer != NULL)
    *trailer = &num[i];

  result = result + ((ULONGEST) high_part << HIGH_BYTE_POSN);
  if (minus)
    return -result;
  else
    return result;
}

/* See documentation in common-utils.h.  */

char *
skip_spaces (char *chp)
{
  if (chp == NULL)
    return NULL;
  while (*chp && isspace (*chp))
    chp++;
  return chp;
}

/* A const-correct version of the above.  */

const char *
skip_spaces (const char *chp)
{
  if (chp == NULL)
    return NULL;
  while (*chp && isspace (*chp))
    chp++;
  return chp;
}

/* See documentation in common-utils.h.  */

const char *
skip_to_space (const char *chp)
{
  if (chp == NULL)
    return NULL;
  while (*chp && !isspace (*chp))
    chp++;
  return chp;
}

/* See documentation in common-utils.h.  */

char *
skip_to_space (char *chp)
{
  return (char *) skip_to_space ((const char *) chp);
}

/* See common/common-utils.h.  */

void
free_vector_argv (std::vector<char *> &v)
{
  for (char *el : v)
    xfree (el);

  v.clear ();
}

/* See common/common-utils.h.  */

std::string
stringify_argv (const std::vector<char *> &args)
{
  std::string ret;

  if (!args.empty () && args[0] != NULL)
    {
      for (auto s : args)
	if (s != NULL)
	  {
	    ret += s;
	    ret += ' ';
	  }

      /* Erase the last whitespace.  */
      ret.erase (ret.end () - 1);
    }

  return ret;
}

/* See common/common-utils.h.  */

bool
is_regular_file (const char *name, int *errno_ptr)
{
  struct stat st;
  const int status = stat (name, &st);

  /* Stat should never fail except when the file does not exist.
     If stat fails, analyze the source of error and return true
     unless the file does not exist, to avoid returning false results
     on obscure systems where stat does not work as expected.  */

  if (status != 0)
    {
      if (errno != ENOENT)
	return true;
      *errno_ptr = ENOENT;
      return false;
    }

  if (S_ISREG (st.st_mode))
    return true;

  if (S_ISDIR (st.st_mode))
    *errno_ptr = EISDIR;
  else
    *errno_ptr = EINVAL;
  return false;
}