quakeforge/tools/qfcc/source/function.c
Bill Currie 80424f6ad5 Ensure functions are always properly terminated.
Control that reaches the end of a function must see a return statement.
2011-01-28 13:14:30 +09:00

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/*
function.c
QC function support code
Copyright (C) 2002 Bill Currie
Author: Bill Currie <bill@taniwha.org>
Date: 2002/5/7
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
static __attribute__ ((used)) const char rcsid[] =
"$Id$";
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <stdlib.h>
#include "QF/dstring.h"
#include "QF/hash.h"
#include "QF/va.h"
#include "qfcc.h"
#include "codespace.h"
#include "debug.h"
#include "def.h"
#include "defspace.h"
#include "diagnostic.h"
#include "emit.h"
#include "expr.h"
#include "function.h"
#include "immediate.h"
#include "opcodes.h"
#include "options.h"
#include "reloc.h"
#include "statements.h"
#include "strpool.h"
#include "symtab.h"
#include "type.h"
static param_t *free_params;
static function_t *free_functions;
static hashtab_t *overloaded_functions;
static hashtab_t *function_map;
static const char *
ol_func_get_key (void *_f, void *unused)
{
overloaded_function_t *f = (overloaded_function_t *) _f;
return f->full_name;
}
static const char *
func_map_get_key (void *_f, void *unused)
{
overloaded_function_t *f = (overloaded_function_t *) _f;
return f->name;
}
param_t *
new_param (const char *selector, type_t *type, const char *name)
{
param_t *param;
ALLOC (4096, param_t, params, param);
param->next = 0;
param->selector = selector;
param->type = type;
param->name = name;
return param;
}
param_t *
param_append_identifiers (param_t *params, symbol_t *idents, type_t *type)
{
param_t **p = &params;
while (*p)
p = &(*p)->next;
if (!idents) {
*p = new_param (0, 0, 0);
p = &(*p)->next;
}
while (idents) {
idents->type = type;
*p = new_param (0, type, idents->name);
(*p)->symbol = idents;
p = &(*p)->next;
idents = idents->next;
}
return params;
}
param_t *
_reverse_params (param_t *params, param_t *next)
{
param_t *p = params;
if (params->next)
p = _reverse_params (params->next, params);
params->next = next;
return p;
}
param_t *
reverse_params (param_t *params)
{
if (!params)
return 0;
return _reverse_params (params, 0);
}
param_t *
copy_params (param_t *params)
{
param_t *n_parms = 0, **p = &n_parms;
while (params) {
*p = new_param (params->selector, params->type, params->name);
params = params->next;
p = &(*p)->next;
}
return n_parms;
}
type_t *
parse_params (type_t *type, param_t *parms)
{
param_t *p;
type_t new;
memset (&new, 0, sizeof (new));
new.type = ev_func;
new.t.func.type = type;
new.t.func.num_params = 0;
for (p = parms; p; p = p->next) {
if (new.t.func.num_params > MAX_PARMS) {
error (0, "too many params");
return type;
}
if (!p->selector && !p->type && !p->name) {
if (p->next) {
error (0, "internal error");
abort ();
}
new.t.func.num_params = -(new.t.func.num_params + 1);
} else if (p->type) {
new.t.func.param_types[new.t.func.num_params] = p->type;
new.t.func.num_params++;
}
}
//print_type (&new); puts("");
return find_type (&new);
}
static overloaded_function_t *
get_function (const char *name, type_t *type, int overload, int create)
{
const char *full_name;
overloaded_function_t *func;
if (!overloaded_functions) {
overloaded_functions = Hash_NewTable (1021, ol_func_get_key, 0, 0);
function_map = Hash_NewTable (1021, func_map_get_key, 0, 0);
}
name = save_string (name);
full_name = save_string (va ("%s|%s", name, encode_params (type)));
func = Hash_Find (overloaded_functions, full_name);
if (func) {
if (func->type != type) {
error (0, "can't overload on return types");
return func;
}
return func;
}
if (!create)
return 0;
func = Hash_Find (function_map, name);
if (func) {
if (!overload && !func->overloaded) {
expr_t *e = new_expr ();
e->line = func->line;
e->file = func->file;
warning (0, "creating overloaded function %s without @overload",
full_name);
warning (e, "(previous function is %s)", func->full_name);
}
overload = 1;
}
func = calloc (1, sizeof (overloaded_function_t));
func->name = name;
func->full_name = full_name;
func->type = type;
func->overloaded = overload;
func->file = pr.source_file;
func->line = pr.source_line;
Hash_Add (overloaded_functions, func);
Hash_Add (function_map, func);
return func;
}
symbol_t *
function_symbol (symbol_t *sym, int overload, int create)
{
const char *name = sym->name;
overloaded_function_t *func;
symbol_t *s;
func = get_function (name, sym->type, overload, create);
if (func && func->overloaded)
name = func->full_name;
s = symtab_lookup (current_symtab, name);
if ((!s || s->table != current_symtab) && create) {
s = new_symbol (name);
s->sy_type = sy_func;
s->type = sym->type;
s->params = sym->params;
s->s.func = 0; // function not yet defined
symtab_addsymbol (current_symtab, s);
}
return s;
}
// NOTE sorts the list in /reverse/ order
static int
func_compare (const void *a, const void *b)
{
overloaded_function_t *fa = *(overloaded_function_t **) a;
overloaded_function_t *fb = *(overloaded_function_t **) b;
type_t *ta = fa->type;
type_t *tb = fb->type;
int na = ta->t.func.num_params;
int nb = tb->t.func.num_params;
int ret, i;
if (na < 0)
na = ~na;
if (nb < 0)
nb = ~nb;
if (na != nb)
return nb - na;
if ((ret = (fb->type->t.func.num_params - fa->type->t.func.num_params)))
return ret;
for (i = 0; i < na && i < nb; i++)
if (ta->t.func.param_types[i] != tb->t.func.param_types[i])
return (long)(tb->t.func.param_types[i] - ta->t.func.param_types[i]);
return 0;
}
expr_t *
find_function (expr_t *fexpr, expr_t *params)
{
expr_t *e;
int i, j, func_count, parm_count, reported = 0;
overloaded_function_t *f, dummy, *best = 0;
type_t type;
void **funcs, *dummy_p = &dummy;
if (fexpr->type != ex_symbol)
return fexpr;
memset (&type, 0, sizeof (type));
for (e = params; e; e = e->next) {
if (e->type == ex_error)
return e;
type.t.func.num_params++;
}
if (type.t.func.num_params > MAX_PARMS)
return fexpr;
for (i = 0, e = params; e; i++, e = e->next) {
type.t.func.param_types[type.t.func.num_params - 1 - i] = get_type (e);
if (e->type == ex_error)
return e;
}
funcs = Hash_FindList (function_map, fexpr->e.symbol->name);
if (!funcs)
return fexpr;
for (func_count = 0; funcs[func_count]; func_count++)
;
if (func_count < 2) {
free (funcs);
return fexpr;
}
type.t.func.type = ((overloaded_function_t *) funcs[0])->type->t.func.type;
dummy.type = find_type (&type);
qsort (funcs, func_count, sizeof (void *), func_compare);
dummy.full_name = save_string (va ("%s|%s", fexpr->e.symbol->name,
encode_params (&type)));
dummy_p = bsearch (&dummy_p, funcs, func_count, sizeof (void *),
func_compare);
if (dummy_p) {
f = (overloaded_function_t *) *(void **) dummy_p;
if (f->overloaded)
fexpr->e.symbol->name = f->full_name;
free (funcs);
return fexpr;
}
for (i = 0; i < func_count; i++) {
f = (overloaded_function_t *) funcs[i];
parm_count = f->type->t.func.num_params;
if ((parm_count >= 0 && parm_count != type.t.func.num_params)
|| (parm_count < 0 && ~parm_count > type.t.func.num_params)) {
funcs[i] = 0;
continue;
}
if (parm_count < 0)
parm_count = ~parm_count;
for (j = 0; j < parm_count; j++) {
if (!type_assignable (f->type->t.func.param_types[j],
type.t.func.param_types[j])) {
funcs[i] = 0;
break;
}
}
if (j < parm_count)
continue;
}
for (i = 0; i < func_count; i++) {
f = (overloaded_function_t *) funcs[i];
if (f) {
if (!best) {
best = f;
} else {
if (!reported) {
reported = 1;
error (fexpr, "unable to disambiguate %s",
dummy.full_name);
error (fexpr, "possible match: %s", best->full_name);
}
error (fexpr, "possible match: %s", f->full_name);
}
}
}
if (reported)
return fexpr;
if (best) {
if (best->overloaded)
fexpr->e.symbol->name = best->full_name;
free (funcs);
return fexpr;
}
error (fexpr, "unable to find function matching %s", dummy.full_name);
free (funcs);
return fexpr;
}
static void
check_function (symbol_t *fsym)
{
param_t *params = fsym->params;
param_t *p;
int i;
if (!type_size (fsym->type->t.func.type)) {
error (0, "return type is an incomplete type");
fsym->type->t.func.type = &type_void;//FIXME better type?
}
if (type_size (fsym->type->t.func.type) > type_size (&type_param)) {
error (0, "return value too large to be passed by value");
fsym->type->t.func.type = &type_void;//FIXME better type?
}
for (p = params, i = 0; p; p = p->next, i++) {
if (!p->selector && !p->type && !p->name)
continue; // ellipsis marker
if (!p->type)
continue; // non-param selector
if (!type_size (p->type))
error (0, "parameter %d (‘%s’) has incomplete type",
i + 1, p->name);
if (type_size (p->type) > type_size (&type_param))
error (0, "param %d (‘%s’) is too large to be passed by value",
i + 1, p->name);
}
}
static void
build_scope (symbol_t *fsym, symtab_t *parent)
{
int i;
param_t *p;
symbol_t *args = 0;
symbol_t *param;
symtab_t *symtab;
check_function (fsym);
symtab = new_symtab (parent, stab_local);
fsym->s.func->symtab = symtab;
symtab->space = new_defspace ();
if (fsym->type->t.func.num_params < 0) {
args = new_symbol_type (".args", &type_va_list);
initialize_def (args, args->type, 0, symtab->space, st_local);
symtab_addsymbol (symtab, args);
}
for (p = fsym->params, i = 0; p; p = p->next) {
if (!p->selector && !p->type && !p->name)
continue; // ellipsis marker
if (!p->type)
continue; // non-param selector
param = new_symbol_type (p->name, p->type);
initialize_def (param, param->type, 0, symtab->space, st_local);
symtab_addsymbol (symtab, param);
i++;
}
if (args) {
while (i < MAX_PARMS) {
param = new_symbol_type (va (".par%d", i), &type_param);
symtab_addsymbol (symtab, param);
i++;
}
}
}
function_t *
new_function (const char *name, const char *nice_name)
{
function_t *f;
ALLOC (1024, function_t, functions, f);
f->s_name = ReuseString (name);
f->s_file = pr.source_file;
if (!(f->name = nice_name))
f->name = name;
return f;
}
void
make_function (symbol_t *sym, const char *nice_name, storage_class_t storage)
{
if (sym->sy_type != sy_func)
internal_error (0, "%s is not a function", sym->name);
if (storage == st_extern && sym->s.func)
return;
if (!sym->s.func) {
sym->s.func = new_function (sym->name, nice_name);
sym->s.func->sym = sym;
}
if (sym->s.func->def && sym->s.func->def->external
&& storage != st_extern) {
free_def (sym->s.func->def);
sym->s.func->def = 0;
}
if (!sym->s.func->def)
sym->s.func->def = new_def (sym->name, sym->type, sym->table->space,
storage);
}
void
add_function (function_t *f)
{
*pr.func_tail = f;
pr.func_tail = &f->next;
f->function_num = pr.num_functions++;
if (options.code.debug)
f->aux = new_auxfunction ();
}
function_t *
begin_function (symbol_t *sym, const char *nicename, symtab_t *parent)
{
if (sym->sy_type != sy_func) {
error (0, "%s is not a function", sym->name);
return 0;
}
if (sym->s.func && sym->s.func->def && sym->s.func->def->initialized) {
error (0, "%s redefined", sym->name);
return 0;
}
make_function (sym, nicename, current_storage);
if (!sym->s.func->def->external) {
sym->s.func->def->initialized = 1;
sym->s.func->def->constant = 1;
sym->s.func->def->nosave = 1;
add_function (sym->s.func);
reloc_def_func (sym->s.func, sym->s.func->def->offset);
}
sym->s.func->code = pr.code->size;
if (options.code.debug && sym->s.func->aux) {
pr_lineno_t *lineno = new_lineno ();
sym->s.func->aux->source_line = sym->s.func->def->line;
sym->s.func->aux->line_info = lineno - pr.linenos;
sym->s.func->aux->local_defs = pr.num_locals;
sym->s.func->aux->return_type = sym->type->t.func.type->type;
lineno->fa.func = sym->s.func->aux - pr.auxfunctions;
}
build_scope (sym, parent);
return sym->s.func;
}
function_t *
build_code_function (symbol_t *fsym, expr_t *state_expr, expr_t *statements)
{
build_function (fsym->s.func);
if (state_expr) {
state_expr->next = statements;
statements = state_expr;
}
emit_function (fsym->s.func, statements);
finish_function (fsym->s.func);
return fsym->s.func;
}
function_t *
build_builtin_function (symbol_t *sym, expr_t *bi_val)
{
int bi;
if (sym->sy_type != sy_func) {
error (bi_val, "%s is not a function", sym->name);
return 0;
}
if (sym->s.func && sym->s.func->def && sym->s.func->def->initialized) {
error (bi_val, "%s redefined", sym->name);
return 0;
}
if (!is_integer_val (bi_val) && !is_float_val (bi_val)) {
error (bi_val, "invalid constant for = #");
return 0;
}
make_function (sym, 0, current_storage);
if (sym->s.func->def->external)
return 0;
add_function (sym->s.func);
if (is_integer_val (bi_val))
bi = expr_integer (bi_val);
else
bi = expr_float (bi_val);
sym->s.func->builtin = bi;
reloc_def_func (sym->s.func, sym->s.func->def->offset);
build_function (sym->s.func);
finish_function (sym->s.func);
// for debug info
//build_scope (f, f->def, sym->params);
//flush_scope (f->scope, 1);
return sym->s.func;
}
void
build_function (function_t *f)
{
// FIXME
// f->def->constant = 1;
// f->def->nosave = 1;
// f->def->initialized = 1;
// G_FUNCTION (f->def->ofs) = f->function_num;
}
void
finish_function (function_t *f)
{
// FIXME
// if (f->aux) {
// def_t *def;
// f->aux->function = f->function_num;
// if (f->scope) {
// for (def = f->scope->head; def; def = def->def_next) {
// if (def->name) {
// def_to_ddef (def, new_local (), 0);
// f->aux->num_locals++;
// }
// }
// }
// }
}
void
emit_function (function_t *f, expr_t *e)
{
sblock_t *sblock;
//statement_t *s;
f->code = pr.code->size;
//printf ("%s %d\n", f->name, f->code);
sblock = make_statements (e);
//for (/**/; sblock; sblock = sblock->next) {
// printf ("block %p\n", sblock);
// for (s = sblock->statements; s; s = s->next) {
// printf (" ");
// print_statement (s);
// }
//}
emit_statements (sblock);
}
int
function_parms (function_t *f, byte *parm_size)
{
//FIXME this is icky
int count, i;
if (f->sym->type->t.func.num_params >= 0)
count = f->sym->type->t.func.num_params;
else
count = -f->sym->type->t.func.num_params - 1;
for (i = 0; i < count; i++)
parm_size[i] = type_size (f->sym->type->t.func.param_types[i]);
return f->sym->type->t.func.num_params;
}