quakeforge/libs/gamecode/pr_resolve.c
Bill Currie 6514e09e7c [gamecode] Use an explicit size for the null page
It's currently only 4 (or even 3 for v6) words, but this fixes false
positives when checking for null pointers in Ruamoko progs due to
pr_return pointing to the return buffer and thus outside the progs
memory map resulting in an impossible to exceed value.
2022-02-01 16:43:29 +09:00

192 lines
5 KiB
C

/*
pr_resolve.c
symbol resolution
Copyright (C) 1996-1997 Id Software, Inc.
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:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include "QF/hash.h"
#include "QF/progs.h"
#include "QF/sys.h"
#include "compat.h"
static const char param_str[] = ".param_0";
pr_def_t *
PR_SearchDefs (pr_def_t *defs, unsigned num_defs, pr_ptr_t offset)
{
// fuzzy bsearh
unsigned left = 0;
unsigned right = num_defs - 1;
unsigned mid;
if (!num_defs) {
return 0;
}
while (left != right) {
mid = (left + right + 1) / 2;
if (defs[mid].ofs > offset) {
right = mid - 1;
} else {
left = mid;
}
}
if (defs[left].ofs <= offset) {
return defs + left;
}
return 0;
}
pr_def_t *
PR_GlobalAtOfs (progs_t * pr, pr_ptr_t ofs)
{
return PR_SearchDefs (pr->pr_globaldefs, pr->progs->globaldefs.count, ofs);
}
VISIBLE pr_def_t *
PR_FieldAtOfs (progs_t * pr, pr_ptr_t ofs)
{
return PR_SearchDefs (pr->pr_fielddefs, pr->progs->fielddefs.count, ofs);
}
VISIBLE pr_def_t *
PR_FindField (progs_t * pr, const char *name)
{
return Hash_Find (pr->field_hash, name);
}
VISIBLE pr_def_t *
PR_FindGlobal (progs_t * pr, const char *name)
{
return Hash_Find (pr->global_hash, name);
}
VISIBLE dfunction_t *
PR_FindFunction (progs_t * pr, const char *name)
{
return Hash_Find (pr->function_hash, name);
}
VISIBLE void
PR_Undefined (progs_t *pr, const char *type, const char *name)
{
PR_Error (pr, "undefined %s %s", type, name);
}
VISIBLE int
PR_ResolveGlobals (progs_t *pr)
{
const char *sym;
pr_def_t *def;
int i;
if (pr->progs->version == PROG_ID_VERSION) {
pr->pr_return = &pr->pr_globals[OFS_RETURN];
pr->pr_params[0] = &pr->pr_globals[OFS_PARM0];
pr->pr_params[1] = &pr->pr_globals[OFS_PARM1];
pr->pr_params[2] = &pr->pr_globals[OFS_PARM2];
pr->pr_params[3] = &pr->pr_globals[OFS_PARM3];
pr->pr_params[4] = &pr->pr_globals[OFS_PARM4];
pr->pr_params[5] = &pr->pr_globals[OFS_PARM5];
pr->pr_params[6] = &pr->pr_globals[OFS_PARM6];
pr->pr_params[7] = &pr->pr_globals[OFS_PARM7];
pr->pr_param_size = OFS_PARM1 - OFS_PARM0;
pr->pr_param_alignment = 0; // log2
} else {
char *param_n = alloca (sizeof (param_str));
strcpy (param_n, param_str);
if (!(def = PR_FindGlobal (pr, sym = ".return")))
goto error;
pr->pr_return = &pr->pr_globals[def->ofs];
for (i = 0; i < PR_MAX_PARAMS; i++) {
param_n[sizeof (param_str) - 2] = i + '0';
if (!(def = PR_FindGlobal (pr, sym = param_n)))
goto error;
pr->pr_params[i] = &pr->pr_globals[def->ofs];
}
if (!(def = PR_FindGlobal (pr, sym = ".param_size")))
goto error;
pr->pr_param_size = G_INT (pr, def->ofs);
if (!(def = PR_FindGlobal (pr, sym = ".param_alignment")))
goto error;
pr->pr_param_alignment = G_INT (pr, def->ofs);
}
pr->null_size = pr->pr_return - pr->pr_globals;
memcpy (pr->pr_real_params, pr->pr_params, sizeof (pr->pr_params));
if (!pr->globals.ftime) {//FIXME double time
if ((def = PR_FindGlobal (pr, "time")))
pr->globals.ftime = &G_FLOAT (pr, def->ofs);
}
if (!pr->globals.self) {
if ((def = PR_FindGlobal (pr, ".self"))
|| (def = PR_FindGlobal (pr, "self")))
pr->globals.self = &G_UINT (pr, def->ofs);
}
if (!pr->globals.stack) {
if ((def = PR_FindGlobal (pr, ".stack"))
|| (def = PR_FindGlobal (pr, "stack"))) {
pr->globals.stack = &G_POINTER (pr, def->ofs);
// the stack is at the very end of the progs memory map
*pr->globals.stack = pr->globals_size;
}
}
if (pr->fields.nextthink == -1)
if ((def = PR_FindField (pr, "nextthink")))
pr->fields.nextthink = def->ofs;
if (pr->fields.frame == -1)
if ((def = PR_FindField (pr, "frame")))
pr->fields.frame = def->ofs;
if (pr->fields.think == -1)
if ((def = PR_FindField (pr, "think")))
pr->fields.think = def->ofs;
return 1;
error:
Sys_Printf ("%s: undefined symbol: %s\n", pr->progs_name, sym);
return 0;
}
int
PR_AccessField (progs_t *pr, const char *name, etype_t type,
const char *file, int line)
{
pr_def_t *def = PR_FindField (pr, name);
if (!def)
PR_Error (pr, "undefined field %s accessed at %s:%d", name, file, line);
if (def->type != type)
PR_Error (pr, "bad type access to %s as %s (should be %s) at %s:%d",
name, pr_type_name[type], pr_type_name[def->type],
file, line);
return def->ofs;
}