quakeforge/tools/qfcc/source/function.c
Bill Currie 0a5101f88c [qfcc] Specify base register index for local defs
While all base registers can be used for any purpose at any time (this
is why the with instruction has hard-absolute modes: you can never get
permanently lost), qfcc currently uses the convention of register 0 for
globals and register 1 for stack locals (params, locals, function args).
The register used to access a def is stored in the def and that is used
to set the register bits in the instruction opcode.

The def code actually doesn't know anything about any conventions: it
assumes all defs are global for non-temp defs (the function code updates
the defs before emitting code) and the current function provides the
register to use for any temp defs allocated while emitting code.

Seems to work well, but debug is utterly messed up (not surprised, that
will be tricky).
2022-01-21 20:34:43 +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
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <stdlib.h>
#include "QF/alloc.h"
#include "QF/dstring.h"
#include "QF/hash.h"
#include "QF/va.h"
#include "tools/qfcc/include/qfcc.h"
#include "tools/qfcc/include/class.h"
#include "tools/qfcc/include/codespace.h"
#include "tools/qfcc/include/debug.h"
#include "tools/qfcc/include/def.h"
#include "tools/qfcc/include/defspace.h"
#include "tools/qfcc/include/diagnostic.h"
#include "tools/qfcc/include/emit.h"
#include "tools/qfcc/include/expr.h"
#include "tools/qfcc/include/flow.h"
#include "tools/qfcc/include/function.h"
#include "tools/qfcc/include/opcodes.h"
#include "tools/qfcc/include/options.h"
#include "tools/qfcc/include/reloc.h"
#include "tools/qfcc/include/shared.h"
#include "tools/qfcc/include/statements.h"
#include "tools/qfcc/include/strpool.h"
#include "tools/qfcc/include/symtab.h"
#include "tools/qfcc/include/type.h"
#include "tools/qfcc/include/value.h"
static param_t *params_freelist;
static function_t *functions_freelist;
static hashtab_t *overloaded_functions;
static hashtab_t *function_map;
// standardized base register to use for all locals (arguments, local defs,
// params)
#define LOCALS_REG 1
static const char *
ol_func_get_key (const void *_f, void *unused)
{
overloaded_function_t *f = (overloaded_function_t *) _f;
return f->full_name;
}
static const char *
func_map_get_key (const 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;
}
static 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 *
append_params (param_t *params, param_t *more_params)
{
if (params) {
param_t *p;
for (p = params; p->next; ) {
p = p->next;
}
p->next = more_params;
return params;
}
return more_params;
}
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;
type_t *ptype;
int count = 0;
if (type && is_class (type)) {
error (0, "cannot return an object (forgot *?)");
type = &type_id;
}
new = new_type ();
new->type = ev_func;
new->alignment = 1;
new->t.func.type = type;
new->t.func.num_params = 0;
for (p = parms; p; p = p->next) {
if (p->type) {
count++;
}
}
if (count) {
new->t.func.param_types = malloc (count * sizeof (type_t));
}
for (p = parms; p; p = p->next) {
if (!p->selector && !p->type && !p->name) {
if (p->next)
internal_error (0, 0);
new->t.func.num_params = -(new->t.func.num_params + 1);
} else if (p->type) {
if (is_class (p->type)) {
error (0, "cannot use an object as a parameter (forgot *?)");
p->type = &type_id;
}
ptype = (type_t *) unalias_type (p->type); //FIXME cast
new->t.func.param_types[new->t.func.num_params] = ptype;
new->t.func.num_params++;
}
}
return new;
}
param_t *
check_params (param_t *params)
{
int num = 1;
param_t *p = params;
if (!params)
return 0;
while (p) {
if (p->type && is_void(p->type)) {
if (p->name) {
error (0, "parameter %d ('%s') has incomplete type", num,
p->name);
p->type = type_default;
} else if (num > 1 || p->next) {
error (0, "'void' must be the only parameter");
p->name = "void";
} else {
// this is a void function
return 0;
}
}
p = p->next;
}
return params;
}
static overloaded_function_t *
get_function (const char *name, const 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, 0);
function_map = Hash_NewTable (1021, func_map_get_key, 0, 0, 0);
}
name = save_string (name);
full_name = save_string (va (0, "%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, unalias_type (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 = (type_t *) unalias_type (sym->type); // FIXME cast
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;
const type_t *ta = fa->type;
const 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));
type.type = ev_func;
for (e = params; e; e = e->next) {
if (e->type == ex_error)
return e;
type.t.func.num_params++;
}
i = type.t.func.num_params * sizeof (type_t);
type.t.func.param_types = alloca(i);
memset (type.t.func.param_types, 0, i);
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) {
f = (overloaded_function_t *) funcs[0];
if (func_count && !f->overloaded) {
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 (0, "%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 = symtab_lookup (current_symtab, f->full_name);
if (!fexpr->e.symbol)
internal_error (fexpr, "overloaded function %s not found",
best->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 = symtab_lookup (current_symtab,
best->full_name);
if (!fexpr->e.symbol)
internal_error (fexpr, "overloaded function %s not found",
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 (%d)",
type_size (&type_param));
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 *parameters;
symtab_t *locals;
symtab_t *cs = current_symtab;//FIXME
check_function (fsym);
fsym->s.func->label_scope = new_symtab (0, stab_local);
parameters = new_symtab (parent, stab_local);
parameters->space = defspace_new (ds_virtual);
fsym->s.func->parameters = parameters;
locals = new_symtab (parameters, stab_local);
locals->space = defspace_new (ds_virtual);
fsym->s.func->locals = locals;
current_symtab = locals;//FIXME
if (!fsym->s.func) {
internal_error (0, "function %s not defined", fsym->name);
}
if (!is_func (fsym->s.func->type)) {
internal_error (0, "function type %s not a funciton", fsym->name);
}
if (fsym->s.func->type->t.func.num_params < 0) {
args = new_symbol_type (".args", &type_va_list);
initialize_def (args, 0, parameters->space, sc_param);
}
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
if (!p->name) {
error (0, "parameter name omitted");
p->name = save_string ("");
}
param = new_symbol_type (p->name, p->type);
initialize_def (param, 0, parameters->space, sc_param);
i++;
}
if (args) {
while (i < MAX_PARMS) {
param = new_symbol_type (va (0, ".par%d", i), &type_param);
initialize_def (param, 0, parameters->space, sc_param);
i++;
}
}
current_symtab = cs;
}
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, defspace_t *space,
storage_class_t storage)
{
reloc_t *relocs = 0;
if (sym->sy_type != sy_func)
internal_error (0, "%s is not a function", sym->name);
if (storage == sc_extern && sym->s.func)
return;
if (!sym->s.func) {
sym->s.func = new_function (sym->name, nice_name);
sym->s.func->sym = sym;
sym->s.func->type = unalias_type (sym->type);
}
if (sym->s.func->def && sym->s.func->def->external
&& storage != sc_extern) {
//FIXME this really is not the right way
relocs = sym->s.func->def->relocs;
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, space, storage);
reloc_attach_relocs (relocs, &sym->s.func->def->relocs);
}
}
void
add_function (function_t *f)
{
*pr.func_tail = f;
pr.func_tail = &f->next;
f->function_num = pr.num_functions++;
}
function_t *
begin_function (symbol_t *sym, const char *nicename, symtab_t *parent,
int far, storage_class_t storage)
{
defspace_t *space;
if (sym->sy_type != sy_func) {
error (0, "%s is not a function", sym->name);
sym = new_symbol_type (sym->name, &type_func);
sym = function_symbol (sym, 1, 1);
}
if (sym->s.func && sym->s.func->def && sym->s.func->def->initialized) {
error (0, "%s redefined", sym->name);
sym = new_symbol_type (sym->name, sym->type);
sym = function_symbol (sym, 1, 1);
}
space = sym->table->space;
if (far)
space = pr.far_data;
make_function (sym, nicename, space, 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);
}
sym->s.func->code = pr.code->size;
sym->s.func->s_file = pr.source_file;
if (options.code.debug) {
pr_lineno_t *lineno = new_lineno ();
sym->s.func->line_info = lineno - pr.linenos;
}
build_scope (sym, parent);
return sym->s.func;
}
static void
build_function (symbol_t *fsym)
{
const type_t *func_type = fsym->s.func->type;
if (func_type->t.func.num_params > MAX_PARMS) {
error (0, "too many params");
}
}
static void
merge_spaces (defspace_t *dst, defspace_t *src, int alignment)
{
int offset;
for (def_t *def = src->defs; def; def = def->next) {
if (def->type->alignment > alignment) {
alignment = def->type->alignment;
}
}
offset = defspace_alloc_aligned_highwater (dst, src->size, alignment);
for (def_t *def = src->defs; def; def = def->next) {
def->offset += offset;
def->space = dst;
}
if (src->defs) {
*dst->def_tail = src->defs;
dst->def_tail = src->def_tail;
src->def_tail = &src->defs;
*src->def_tail = 0;
}
defspace_delete (src);
}
function_t *
build_code_function (symbol_t *fsym, expr_t *state_expr, expr_t *statements)
{
if (fsym->sy_type != sy_func) // probably in error recovery
return 0;
build_function (fsym);
if (state_expr) {
state_expr->next = statements;
statements = state_expr;
}
function_t *func = fsym->s.func;
if (options.code.progsversion == PROG_VERSION) {
expr_t *e;
e = new_with_expr (2, LOCALS_REG, new_short_expr (0));
e->next = statements;
e->file = func->def->file;
e->line = func->def->line;
statements = e;
e = new_adjstk_expr (0, 0);
e->next = statements;
e->file = func->def->file;
e->line = func->def->line;
statements = e;
func->temp_reg = LOCALS_REG;
for (def_t *def = func->locals->space->defs; def; def = def->next) {
if (def->local || def->param) {
def->reg = LOCALS_REG;
}
}
for (def_t *def = func->parameters->space->defs; def; def = def->next) {
if (def->local || def->param) {
def->reg = LOCALS_REG;
}
}
}
emit_function (func, statements);
if (options.code.progsversion < PROG_VERSION) {
// stitch parameter and locals data together with parameters coming
// first
defspace_t *space = defspace_new (ds_virtual);
merge_spaces (space, func->parameters->space, 1);
func->parameters->space = space;
merge_spaces (space, func->locals->space, 1);
func->locals->space = space;
} else {
defspace_t *space = defspace_new (ds_virtual);
if (func->arguments) {
func->arguments->size = func->arguments->max_size;
merge_spaces (space, func->arguments, 4);
func->arguments = 0;
}
merge_spaces (space, func->locals->space, 4);
func->locals->space = space;
// allocate 0 words to force alignment
defspace_alloc_aligned_highwater (space, 0, 4);
dstatement_t *st = &pr.code->code[func->code];
if (st->op == OP_ADJSTK) {
st->b = -space->size;
}
merge_spaces (space, func->parameters->space, 4);
func->parameters->space = space;
}
return fsym->s.func;
}
function_t *
build_builtin_function (symbol_t *sym, expr_t *bi_val, int far,
storage_class_t storage)
{
int bi;
defspace_t *space;
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_int_val (bi_val) && !is_float_val (bi_val)) {
error (bi_val, "invalid constant for = #");
return 0;
}
space = sym->table->space;
if (far)
space = pr.far_data;
make_function (sym, 0, space, storage);
if (sym->s.func->def->external)
return 0;
sym->s.func->def->initialized = 1;
sym->s.func->def->constant = 1;
sym->s.func->def->nosave = 1;
add_function (sym->s.func);
if (is_int_val (bi_val))
bi = expr_int (bi_val);
else
bi = expr_float (bi_val);
if (bi < 0) {
error (bi_val, "builtin functions must be positive or 0");
return 0;
}
sym->s.func->builtin = bi;
reloc_def_func (sym->s.func, sym->s.func->def);
build_function (sym);
// for debug info
build_scope (sym, current_symtab);
sym->s.func->parameters->space->size = 0;
sym->s.func->locals->space = sym->s.func->parameters->space;
return sym->s.func;
}
void
emit_function (function_t *f, expr_t *e)
{
if (pr.error_count)
return;
f->code = pr.code->size;
lineno_base = f->def->line;
f->sblock = make_statements (e);
if (options.code.optimize) {
flow_data_flow (f);
} else {
statements_count_temps (f->sblock);
}
emit_statements (f->sblock);
}
int
function_parms (function_t *f, byte *parm_size)
{
int count, i;
ty_func_t *func = &f->sym->type->t.func;
if (func->num_params >= 0)
count = func->num_params;
else
count = -func->num_params - 1;
for (i = 0; i < count; i++)
parm_size[i] = type_size (func->param_types[i]);
return func->num_params;
}
void
clear_functions (void)
{
if (overloaded_functions)
Hash_FlushTable (overloaded_functions);
if (function_map)
Hash_FlushTable (function_map);
}