ref: 878d46d965b83832a939cc46707aa6f3b7e5d30e
dir: /src/cmd/cc/cc1/init.c/
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <scc/cstd.h>
#include <scc/scc.h>
#include "cc1.h"
typedef struct init Init;
struct designator {
TINT pos;
Node *expr;
struct designator *next;
};
struct init {
TUINT pos;
TUINT max;
struct designator *tail;
struct designator *head;
};
static TINT
arydesig(Type *tp, Init *ip)
{
TINT npos;
Node *np;
if (tp->op != ARY)
errorp("array index in non-array initializer");
next();
np = constexpr();
npos = np->sym->u.i;
if (npos < 0 || (tp->prop & TDEFINED) && npos >= tp->n.elem) {
errorp("array index in initializer exceeds array bounds");
npos = 0;
}
freetree(np);
expect(']');
return npos;
}
static TINT
fielddesig(Type *tp, Init *ip)
{
int ons;
Symbol *sym, **p;
if (!(tp->prop & TAGGREG))
errorp("field name not in record or union initializer");
ons = namespace;
namespace = tp->ns;
next();
namespace = ons;
if (yytoken != IDEN)
unexpected();
sym = yylval.sym;
next();
if ((sym->flags & SDECLARED) == 0) {
errorp("unknown field '%s' specified in initializer",
sym->name);
return 0;
}
for (p = tp->p.fields; *p != sym; ++p)
;
return p - tp->p.fields;
}
static Init *
init(Init *ip)
{
ip->tail = ip->head = NULL;
ip->pos = ip->max = 0;
return ip;
}
static Node *
str2ary(Type *tp)
{
Node *np;
Type *btp = tp->type;
Symbol *sym;
size_t len;
char *s;
np = assign();
sym = np->left->sym;
if (btp != chartype && btp != uchartype && btp != schartype) {
errorp("array of inappropriate type initialized from string constant");
return constnode(zero);
}
len = sym->type->n.elem-1;
if (!(tp->prop & TDEFINED)) {
tp->n.elem = len+1;
deftype(tp);
} else if (tp->n.elem < len) {
warn("initializer-string for array of chars is too long");
}
len = tp->n.elem;
s = sym->u.s;
sym = newstring(NULL, len);
strncpy(sym->u.s, s, len);
np->sym = sym;
np->type = sym->type;
return np;
}
static Node *
initialize(Type *tp)
{
Node *np;
Symbol *sym;
if (tp->op == ARY && yytoken == STRING)
return str2ary(tp);
if (yytoken == '{' || tp->op == STRUCT || tp->op == ARY)
return initlist(tp);
np = assign();
if (eqtype(tp, np->type, 1))
return np;
np = convert(decay(np), tp, 0);
if (!np) {
errorp("incorrect initializer");
return constnode(zero);
}
return simplify(np);
}
static Node *
mkcompound(Init *ip, Type *tp)
{
Node **v, **p, *np;
size_t n;
struct designator *dp, *next;
Symbol *sym;
int isconst = 1;
if (tp->op == UNION) {
np = NULL;
v = xmalloc(sizeof(*v));
for (dp = ip->head; dp; dp = next) {
freetree(np);
np = dp->expr;
next = dp->next;
free(dp);
}
if ((np->flags & NCONST) == 0)
isconst = 0;
*v = np;
} else {
n = (tp->prop&TDEFINED) ? tp->n.elem : ip->max;
if (n == 0) {
v = NULL;
} else if (n > SIZE_MAX / sizeof(*v)) {
errorp("compound literal too big");
return constnode(zero);
} else {
n *= sizeof(*v);
v = memset(xmalloc(n), 0, n);
for (dp = ip->head; dp; dp = next) {
p = &v[dp->pos];
freetree(*p);
np = dp->expr;
*p = np;
if ((np->flags & NCONST) == 0)
isconst = 0;
next = dp->next;
free(dp);
}
}
}
sym = newsym(NS_IDEN, NULL);
sym->u.init = v;
sym->type = tp;
sym->flags |= SINITLST;
return (isconst ? constnode : varnode)(sym);
}
static void
newdesig(Init *ip, Node *np)
{
struct designator *dp;
dp = xmalloc(sizeof(*dp));
dp->pos = ip->pos;
dp->expr = np;
dp->next = NULL;
if (ip->head == NULL) {
ip->head = ip->tail = dp;
} else {
ip->tail->next = dp;
ip->tail = dp;
}
if (ip->pos+1 > ip->max)
ip->max = ip->pos+1;
}
static Node *
initlist_helper(Type *tp)
{
Init in;
Node *np;
Type *curtp;
int braces, scalar, toomany, outbound;
TINT nelem = tp->n.elem;
init(&in);
braces = scalar = toomany = 0;
if (accept('{'))
braces = 1;
for (;;) {
curtp = inttype;
switch (yytoken) {
case '[':
in.pos = arydesig(tp, &in);
curtp = tp->type;
goto desig_list;
case '.':
in.pos = fielddesig(tp, &in);
if (in.pos < nelem)
curtp = tp->p.fields[in.pos]->type;
desig_list:
if (yytoken == '[' || yytoken == '.') {
np = initlist(curtp);
goto new_desig;
}
expect('=');
default:
outbound = 0;
switch (tp->op) {
case ARY:
curtp = tp->type;
if (!(tp->prop & TDEFINED) || in.pos < tp->n.elem)
break;
if (!toomany)
warn("excess elements in array initializer");
toomany = 1;
outbound = 1;
break;
case UNION:
case STRUCT:
if (in.pos < nelem) {
curtp = tp->p.fields[in.pos]->type;
break;
}
if (!toomany)
warn("excess elements in struct initializer");
toomany = 1;
outbound = 1;
break;
default:
curtp = tp;
if (!scalar)
warn("braces around scalar initializer");
scalar = 1;
if (in.pos == 0)
break;
if (!toomany)
warn("excess elements in scalar initializer");
toomany = 1;
outbound = 1;
break;
}
np = initialize(curtp);
if (outbound) {
freetree(np);
np = NULL;
}
}
new_desig:
if (np)
newdesig(&in, np);
if (++in.pos == 0)
errorp("compound literal too big");
if (nelem == in.pos && !braces)
break;
if (!accept(','))
break;
if (yytoken == '}')
break;
}
if (braces)
expect('}');
if (tp->op == ARY && !(tp->prop & TDEFINED)) {
tp->n.elem = in.max;
deftype(tp);
}
if (in.max == 0) {
errorp("empty braced initializer");
return constnode(zero);
}
return mkcompound(&in, tp);
}
Node *
initlist(Type *tp)
{
Node *np;
static int depth;
if (depth == NR_SUBTYPE)
error("too many nested initializers");
++depth;
np = initlist_helper(tp);
--depth;
return np;
}
static void
autoinit(Symbol *sym, Node *np)
{
Symbol *hidden;
Type *tp = sym->type;
size_t n; /* FIXME: It should be SIZET */
repeat:
switch (tp->op) {
case UNION:
np = np->sym->u.init[0];
tp = np->type;
goto repeat;
case ARY:
case STRUCT:
if (!(np->flags & NCONST))
abort(); /* TODO */
hidden = newsym(NS_IDEN, NULL);
hidden->id = newid();
hidden->type = sym->type;
hidden->flags |= SLOCAL | SHASINIT;
emit(ODECL, hidden);
emit(OINIT, np);
emit(ODECL, sym);
emit(OEXPR,
node(OASSIGN, tp, varnode(sym), varnode(hidden)));
break;
default:
emit(ODECL, sym);
np = node(OASSIGN, tp, varnode(sym), np);
emit(OEXPR, np);
break;
}
}
void
initializer(Symbol *sym, Type *tp)
{
Node *np;
int flags = sym->flags;
if (tp->op == FTN) {
errorp("function '%s' initialized like a variable",
sym->name);
tp = inttype;
}
np = initialize(tp);
if (flags & SDEFINED) {
errorp("redeclaration of '%s'", sym->name);
} else if ((flags & (SGLOBAL|SLOCAL|SPRIVATE)) != 0) {
if ((np->flags & NCONST) == 0) {
errorp("initializer element is not constant");
return;
}
sym->flags |= SHASINIT;
sym->flags &= ~SEMITTED;
emit(ODECL, sym);
emit(OINIT, np);
sym->flags |= SDEFINED;
} else if ((flags & (SEXTERN|STYPEDEF)) != 0) {
errorp("'%s' has both '%s' and initializer",
sym->name, (flags&SEXTERN) ? "extern" : "typedef");
} else {
autoinit(sym, np);
}
}