quakeforge/tools/qfcc/source/struct.c
Bill Currie 6253d775e6 [qfcc] Adjust ivar offsets to preserve alignment
As a class's ivars are built up by inheritance, but with only that
class's ivars in the symbol table, is is necessary to include an offset
based on the super class's ivars in order to ensure alignments are
respected. This is achieved via the new `base` parameter to
build_struct(), which is used to offset the current size while
calculating the aligned offset of the symbols. The parameter is ignored
for unions, as they always start at 0. The ivars for the current class
still have a base offset of 0 until they are actually added to the
class.

Fixes #29
2022-07-31 17:15:47 +09:00

384 lines
10 KiB
C

/*
struct.c
structure support
Copyright (C) 2001 Bill Currie <bill@taniwha.org>
Copyright (C) 2011 Bill Currie <bill@taniwha.org>
Author: Bill Currie <bill@taniwha.org>
Date: 2001/12/08
Date: 2011/01/17
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/dstring.h>
#include <QF/hash.h>
#include <QF/sys.h>
#include <QF/va.h>
#include <QF/progs/pr_obj.h>
#include "tools/qfcc/include/class.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/obj_type.h"
#include "tools/qfcc/include/qfcc.h"
#include "tools/qfcc/include/reloc.h"
#include "tools/qfcc/include/shared.h"
#include "tools/qfcc/include/strpool.h"
#include "tools/qfcc/include/struct.h"
#include "tools/qfcc/include/symtab.h"
#include "tools/qfcc/include/type.h"
#include "tools/qfcc/include/value.h"
static symbol_t *
find_tag (ty_meta_e meta, symbol_t *tag, type_t *type)
{
const char *tag_name;
symbol_t *sym;
if (tag) {
tag_name = va (0, "tag %s", tag->name);
} else {
const char *path = GETSTR (pr.source_file);
const char *file = strrchr (path, '/');
if (!file++)
file = path;
tag_name = va (0, "tag .%s.%d", file, pr.source_line);
}
sym = symtab_lookup (current_symtab, tag_name);
if (sym) {
if (sym->table == current_symtab && sym->type->meta != meta)
error (0, "%s defined as wrong kind of tag", tag->name);
if (sym->type->meta == meta)
return sym;
}
sym = new_symbol (tag_name);
if (!type)
type = new_type ();
if (!type->name)
type->name = sym->name;
sym->type = type;
sym->type->type = ev_invalid;
sym->type->meta = meta;
sym->sy_type = sy_type;
return sym;
}
symbol_t *
find_struct (int su, symbol_t *tag, type_t *type)
{
ty_meta_e meta = ty_struct;
if (su == 'u')
meta = ty_union;
return find_tag (meta, tag, type);
}
symbol_t *
build_struct (int su, symbol_t *tag, symtab_t *symtab, type_t *type, int base)
{
symbol_t *sym = find_struct (su, tag, type);
symbol_t *s;
int alignment = 1;
symbol_t *as;
symtab->parent = 0; // disconnect struct's symtab from parent scope
if (sym->table == current_symtab && sym->type->t.symtab) {
error (0, "%s defined as wrong kind of tag", tag->name);
return sym;
}
for (s = symtab->symbols; s; s = s->next) {
if (s->sy_type != sy_var)
continue;
if (is_class (s->type)) {
error (0, "statically allocated instance of class %s",
s->type->t.class->name);
}
if (su == 's') {
symtab->size = RUP (symtab->size + base, s->type->alignment) - base;
s->s.offset = symtab->size;
symtab->size += type_size (s->type);
} else {
int size = type_size (s->type);
if (size > symtab->size)
symtab->size = size;
}
if (s->type->alignment > alignment) {
alignment = s->type->alignment;
}
if (s->visibility == vis_anonymous) {
symtab_t *anonymous;
symbol_t *t = s->next;
int offset = s->s.offset;
if (!is_struct (s->type)) {
internal_error (0, "non-struct/union anonymous field");
}
anonymous = s->type->t.symtab;
for (as = anonymous->symbols; as; as = as->next) {
if (as->visibility == vis_anonymous || as->sy_type!= sy_var) {
continue;
}
if (Hash_Find (symtab->tab, as->name)) {
error (0, "ambiguous field `%s' in anonymous %s",
as->name, su == 's' ? "struct" : "union");
} else {
s->next = copy_symbol (as);
s = s->next;
s->s.offset += offset;
s->table = symtab;
Hash_Add (symtab->tab, s);
}
}
s->next = t;
}
}
if (!type)
sym->type = find_type (sym->type); // checks the tag, not the symtab
sym->type->t.symtab = symtab;
if (alignment > sym->type->alignment) {
sym->type->alignment = alignment;
}
if (!type && sym->type->type_def->external) //FIXME should not be necessary
sym->type->type_def = qfo_encode_type (sym->type, pr.type_data);
return sym;
}
symbol_t *
find_enum (symbol_t *tag)
{
return find_tag (ty_enum, tag, 0);
}
symtab_t *
start_enum (symbol_t *sym)
{
if (sym->table == current_symtab && sym->type->t.symtab) {
error (0, "%s defined as wrong kind of tag", sym->name);
sym = find_enum (0);
}
sym->type->t.symtab = new_symtab (current_symtab, stab_local);
sym->type->alignment = 1;
sym->type->width = 1;
return sym->type->t.symtab;
}
symbol_t *
finish_enum (symbol_t *sym)
{
symbol_t *enum_sym;
symbol_t *name;
type_t *enum_type;
symtab_t *enum_tab;
enum_type = sym->type = find_type (sym->type);
enum_tab = enum_type->t.symtab;
for (name = enum_tab->symbols; name; name = name->next) {
name->type = sym->type;
enum_sym = new_symbol_type (name->name, enum_type);
enum_sym->sy_type = sy_const;
enum_sym->s.value = name->s.value;
symtab_addsymbol (enum_tab->parent, enum_sym);
}
return sym;
}
void
add_enum (symbol_t *enm, symbol_t *name, expr_t *val)
{
type_t *enum_type = enm->type;
symtab_t *enum_tab = enum_type->t.symtab;
int value;
if (name->table == current_symtab || name->table == enum_tab)
error (0, "%s redefined", name->name);
if (name->table)
name = new_symbol (name->name);
name->sy_type = sy_const;
name->type = enum_type;
value = 0;
if (enum_tab->symbols)
value = ((symbol_t *)(enum_tab->symtail))->s.value->v.int_val + 1;
if (val) {
convert_name (val);
if (!is_constant (val))
error (val, "non-constant initializer");
else if (!is_int_val (val))
error (val, "invalid initializer type");
else
value = expr_int (val);
}
name->s.value = new_int_val (value);
symtab_addsymbol (enum_tab, name);
}
int
enum_as_bool (type_t *enm, expr_t **zero, expr_t **one)
{
symtab_t *symtab = enm->t.symtab;
symbol_t *zero_sym = 0;
symbol_t *one_sym = 0;
symbol_t *sym;
int val, v;
if (!symtab)
return 0;
for (sym = symtab->symbols; sym; sym = sym->next) {
if (sym->sy_type != sy_const)
continue;
val = sym->s.value->v.int_val;
if (!val) {
zero_sym = sym;
} else {
if (one_sym) {
v = one_sym->s.value->v.int_val;
if (val * val > v * v)
continue;
}
one_sym = sym;
}
}
if (!zero_sym || !one_sym)
return 0;
*zero = new_symbol_expr (zero_sym);
*one = new_symbol_expr (one_sym);
return 1;
}
symbol_t *
make_structure (const char *name, int su, struct_def_t *defs, type_t *type)
{
symtab_t *strct;
symbol_t *field;
symbol_t *sym = 0;
if (name)
sym = new_symbol (name);
if (su == 'u')
strct = new_symtab (0, stab_union);
else
strct = new_symtab (0, stab_struct);
while (defs->name) {
field = new_symbol_type (defs->name, defs->type);
field->sy_type = sy_var;
if (!symtab_addsymbol (strct, field))
internal_error (0, "duplicate symbol: %s", defs->name);
defs++;
}
sym = build_struct (su, sym, strct, type, 0);
return sym;
}
def_t *
emit_structure (const char *name, int su, struct_def_t *defs, type_t *type,
void *data, defspace_t *space, storage_class_t storage)
{
int i, j;
int saw_null = 0;
int saw_func = 0;
symbol_t *struct_sym;
symbol_t *field_sym;
def_t *struct_def;
def_t field_def;
name = save_string (name);
if (!type)
type = make_structure (0, su, defs, 0)->type;
if (!is_struct (type) || (su == 's' && type->meta != ty_struct)
|| (su == 'u' && type->meta != ty_union))
internal_error (0, "structure %s type mismatch", name);
for (i = 0, field_sym = type->t.symtab->symbols; field_sym;
i++, field_sym = field_sym->next) {
if (!defs[i].name)
internal_error (0, "structure %s unexpected end of defs", name);
if (field_sym->type != defs[i].type)
internal_error (0, "structure %s.%s field type mismatch", name,
defs[i].name);
if ((!defs[i].emit && saw_func) || (defs[i].emit && saw_null))
internal_error (0, "structure %s mixed emit/copy", name);
if (!defs[i].emit)
saw_null = 1;
if (defs[i].emit)
saw_func = 1;
}
if (defs[i].name)
internal_error (0, "structure %s too many defs", name);
if (storage != sc_global && storage != sc_static)
internal_error (0, "structure %s must be global or static", name);
if (!space) {
space = pr.far_data;
}
struct_sym = make_symbol (name, type, space, storage);
struct_def = struct_sym->s.def;
if (struct_def->initialized)
internal_error (0, "structure %s already initialized", name);
struct_def->initialized = struct_def->constant = 1;
struct_def->nosave = 1;
for (i = 0, field_sym = type->t.symtab->symbols; field_sym;
i++, field_sym = field_sym->next) {
field_def.type = field_sym->type;
field_def.name = save_string (va (0, "%s.%s", name, field_sym->name));
field_def.space = struct_def->space;
field_def.offset = struct_def->offset + field_sym->s.offset;
if (!defs[i].emit) {
//FIXME relocs? arrays? structs?
pr_type_t *val = (pr_type_t *) data;
memcpy (D_POINTER (pr_type_t, &field_def), val,
type_size (field_def.type) * sizeof (pr_type_t));
data = &val[type_size (field_def.type)];
} else {
if (is_array (field_def.type)) {
type_t *type = field_def.type->t.array.type;
for (j = 0; j < field_def.type->t.array.size; j++) {
defs[i].emit (&field_def, data, j);
field_def.offset += type_size (type);
}
} else {
defs[i].emit (&field_def, data, 0);
}
}
}
return struct_def;
}