binutils-gdb/gdb/gdb_obstack.h
Pedro Alves 8268c77870 Eliminate make_cleanup_obstack_free, introduce auto_obstack
This commit eliminates make_cleanup_obstack_free, replacing it with a
new auto_obstack type that inherits obstack to add cdtors.

These changes in the parsers may not be obvious:

 -  obstack_init (&name_obstack);
 -  make_cleanup_obstack_free (&name_obstack);
 +  name_obstack.clear ();

Here, the 'name_obstack' variable is a global.  The change means that
the obstack's contents from a previous parse will stay around until
the next parsing starts.  I.e., memory won't be reclaimed until then.
I don't think that's a problem, these objects don't really grow much
at all.

The other option I tried was to add a separate type that is like
auto_obstack but manages an external obstack, just for those cases.  I
like the current approach better as that other approach adds more
boilerplate and yet another type to learn.

gdb/ChangeLog:
2017-06-27  Pedro Alves  <palves@redhat.com>

	* c-exp.y (name_obstack): Now an auto_obstack.
	(yylex): Use auto_obstack::clear.
	(c_parse): Use auto_obstack::clear instead of reinitializing and
	freeing the obstack.
	* c-lang.c (evaluate_subexp_c): Use auto_obstack.
	* d-exp.y (name_obstack): Now an auto_obstack.
	(yylex): Use auto_obstack::clear.
	(d_parse): Use auto_obstack::clear instead of reinitializing and
	freeing the obstack.
	* dwarf2loc.c (fetch_const_value_from_synthetic_pointer): Use
	auto_obstack.
	* dwarf2read.c (create_addrmap_from_index)
	(dwarf2_build_psymtabs_hard)
	(update_enumeration_type_from_children): Likewise.
	* gdb_obstack.h (auto_obstack): New type.
	* go-exp.y (name_obstack): Now an auto_obstack.
	(build_packaged_name): Use auto_obstack::clear.
	(go_parse): Use auto_obstack::clear instead of reinitializing and
	freeing the obstack.
	* linux-tdep.c (linux_make_mappings_corefile_notes): Use
	auto_obstack.
	* printcmd.c (printf_wide_c_string, ui_printf): Use auto_obstack.
	* rust-exp.y (work_obstack): Now an auto_obstack.
	(rust_parse, rust_lex_tests): Use auto_obstack::clear instead of
	reinitializing and freeing the obstack.
	* utils.c (do_obstack_free, make_cleanup_obstack_free): Delete.
	(host_char_to_target): Use auto_obstack.
	* utils.h (make_cleanup_obstack_free): Delete declaration.
	* valprint.c (generic_emit_char, generic_printstr): Use
	auto_obstack.
2017-06-27 11:07:14 +01:00

82 lines
2.8 KiB
C

/* Obstack wrapper for GDB.
Copyright (C) 2002-2017 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/>. */
#if !defined (GDB_OBSTACK_H)
#define GDB_OBSTACK_H 1
#include "obstack.h"
/* Utility macros - wrap obstack alloc into something more robust. */
#define OBSTACK_ZALLOC(OBSTACK,TYPE) \
((TYPE *) memset (obstack_alloc ((OBSTACK), sizeof (TYPE)), 0, sizeof (TYPE)))
#define OBSTACK_CALLOC(OBSTACK,NUMBER,TYPE) \
((TYPE *) memset (obstack_alloc ((OBSTACK), (NUMBER) * sizeof (TYPE)), \
0, (NUMBER) * sizeof (TYPE)))
/* Unless explicitly specified, GDB obstacks always use xmalloc() and
xfree(). */
/* Note: ezannoni 2004-02-09: One could also specify the allocation
functions using a special init function for each obstack,
obstack_specify_allocation. However we just use obstack_init and
let these defines here do the job. While one could argue the
superiority of one approach over the other, we just chose one
throughout. */
#define obstack_chunk_alloc xmalloc
#define obstack_chunk_free xfree
#define obstack_grow_str(OBSTACK,STRING) \
obstack_grow (OBSTACK, STRING, strlen (STRING))
#define obstack_grow_str0(OBSTACK,STRING) \
obstack_grow0 (OBSTACK, STRING, strlen (STRING))
#define obstack_grow_wstr(OBSTACK, WSTRING) \
obstack_grow (OBSTACK, WSTRING, sizeof (gdb_wchar_t) * gdb_wcslen (WSTRING))
/* Concatenate NULL terminated variable argument list of `const char
*' strings; return the new string. Space is found in the OBSTACKP.
Argument list must be terminated by a sentinel expression `(char *)
NULL'. */
extern char *obconcat (struct obstack *obstackp, ...) ATTRIBUTE_SENTINEL;
/* Duplicate STRING, returning an equivalent string that's allocated on the
obstack OBSTACKP. */
extern char *obstack_strdup (struct obstack *obstackp, const char *string);
/* An obstack that frees itself on scope exit. */
struct auto_obstack : obstack
{
auto_obstack ()
{ obstack_init (this); }
~auto_obstack ()
{ obstack_free (this, NULL); }
/* Free all memory in the obstack but leave it valid for further
allocation. */
void clear ()
{ obstack_free (this, obstack_base (this)); }
};
#endif