binutils-gdb/gdb/common/common-utils.c
Sergio Durigan Junior 7c5ded6a00 C++-fy and prepare for sharing fork_inferior
As a preparation for the next patch, which will move fork_inferior
from GDB to common/ (and therefore share it with gdbserver), it is
interesting to convert a few functions to C++.

This patch touches functions related to parsing command-line arguments
to the inferior (see gdb/fork-child.c:breakup_args), the way the
arguments are stored on fork_inferior (using std::vector instead of
char **), and the code responsible for dealing with argv also on
gdbserver.

I've taken this opportunity and decided to constify a few arguments to
fork_inferior/create_inferior as well, in order to make the code
cleaner.  And now, on gdbserver, we're using xstrdup everywhere and
aren't checking for memory allocation failures anymore, as requested
by Pedro:

  <https://sourceware.org/ml/gdb-patches/2017-03/msg00191.html>
  Message-Id: <025ebdb9-90d9-d54a-c055-57ed2406b812@redhat.com>

  Pedro Alves wrote:

  > On the "== NULL" check: IIUC, the old NULL check was there to
  > handle strdup returning NULL due to out-of-memory.
  > See NULL checks and comments further above in this function.
  > Now that you're using a std::vector, that doesn't work or make
  > sense any longer, since if push_back fails to allocate space for
  > its internal buffer (with operator new), our operator new replacement
  > (common/new-op.c) calls malloc_failure, which aborts gdbserver.
  >
  > Not sure it makes sense to handle out-of-memory specially in
  > the gdb/rsp-facing functions nowadays (maybe git blame/log/patch
  > submission for that code shows some guidelines).  Maybe (or, probably)
  > it's OK to stop caring about it, but then we should consistently remove
  > left over code, by using xstrdup instead and remove the NULL checks.

IMO this refactoring was very good to increase the readability of the
code as well, because some parts of the argument handling were
unnecessarily confusing before.

gdb/ChangeLog:
2017-04-12  Sergio Durigan Junior  <sergiodj@redhat.com>

	* common/common-utils.c (free_vector_argv): New function.
	* common/common-utils.h: Include <vector>.
	(free_vector_argv): New prototype.
	* darwin-nat.c (darwin_create_inferior): Rewrite function
	prototype in order to constify "exec_file" and accept a
	"std::string" for "allargs".
	* fork-child.c: Include <vector>.
	(breakup_args): Rewrite function, using C++.
	(fork_inferior): Rewrite function header, constify "exec_file_arg"
	and accept "std::string" for "allargs".  Update the code to
	calculate "argv" based on "allargs".  Update calls to "exec_fun"
	and "execvp".
	* gnu-nat.c (gnu_create_inferior): Rewrite function prototype in
	order to constify "exec_file" and accept a "std::string" for
	"allargs".
	* go32-nat.c (go32_create_inferior): Likewise.
	* inf-ptrace.c (inf_ptrace_create_inferior): Likewise.
	* infcmd.c (run_command_1): Constify "exec_file".  Use
	"std::string" for inferior arguments.
	* inferior.h (fork_inferior): Update prototype.
	* linux-nat.c (linux_nat_create_inferior): Rewrite function
	prototype in order to constify "exec_file" and accept a
	"std::string" for "allargs".
	* nto-procfs.c (procfs_create_inferior): Likewise.
	* procfs.c (procfs_create_inferior): Likewise.
	* remote-sim.c (gdbsim_create_inferior): Likewise.
	* remote.c (extended_remote_run): Update code to accept
	"std::string" as argument.
	(extended_remote_create_inferior): Rewrite function prototype in
	order to constify "exec_file" and accept a "std::string" for
	"allargs".
	* rs6000-nat.c (super_create_inferior): Likewise.
	(rs6000_create_inferior): Likewise.
	* target.h (struct target_ops) <to_create_inferior>: Likewise.
	* windows-nat.c (windows_create_inferior): Likewise.

gdb/gdbserver/ChangeLog:
2017-04-12  Sergio Durigan Junior  <sergiodj@redhat.com>

	* server.c: Include <vector>.
	<program_argv, wrapper_argv>: Convert to std::vector.
	(start_inferior): Rewrite function to use C++.
	(handle_v_run): Likewise.  Update code that calculates the argv
	based on the vRun packet; use C++.
	(captured_main): Likewise.
2017-04-12 01:02:03 -04:00

331 lines
6.6 KiB
C

/* Shared general utility routines for GDB, the GNU debugger.
Copyright (C) 1986-2017 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 "host-defs.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
xfree (void *ptr)
{
if (ptr != NULL)
free (ptr); /* ARI: free */
}
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;
}
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 (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 (const char *chp)
{
if (chp == NULL)
return NULL;
while (*chp && !isspace (*chp))
chp++;
return chp;
}
/* See common/common-utils.h. */
void
free_vector_argv (std::vector<char *> &v)
{
for (char *el : v)
xfree (el);
v.clear ();
}