static yasm_expr *
expr_expand_equ(yasm_expr *e, yasm__exprhead *eh)
{
int i;
yasm__exprentry ee;
/* traverse terms */
for (i=0; i<e->numterms; i++) {
const yasm_expr *equ_expr;
/* Expand equ's. */
if (e->terms[i].type == YASM_EXPR_SYM &&
(equ_expr = yasm_symrec_get_equ(e->terms[i].data.sym))) {
yasm__exprentry *np;
/* Check for circular reference */
SLIST_FOREACH(np, eh, next) {
if (np->e == equ_expr) {
yasm_error_set(YASM_ERROR_TOO_COMPLEX,
N_("circular reference detected"));
return e;
}
}
e->terms[i].type = YASM_EXPR_EXPR;
e->terms[i].data.expn = yasm_expr_copy(equ_expr);
/* Remember we saw this equ and recurse */
ee.e = equ_expr;
SLIST_INSERT_HEAD(eh, &ee, next);
e->terms[i].data.expn = expr_expand_equ(e->terms[i].data.expn, eh);
SLIST_REMOVE_HEAD(eh, next);
} else if (e->terms[i].type == YASM_EXPR_EXPR)
static int
value_finalize_scan(yasm_value *value, yasm_expr *e,
/*@null@*/ yasm_bytecode *expr_precbc, int ssym_not_ok)
{
int i;
/*@dependent@*/ yasm_section *sect;
/*@dependent@*/ /*@null@*/ yasm_bytecode *precbc;
unsigned long shamt; /* for SHR */
/* Yes, this has a maximum upper bound on 32 terms, based on an
* "insane number of terms" (and ease of implementation) WAG.
* The right way to do this would be a stack-based alloca, but that's
* not ISO C. We really don't want to malloc here as this function is
* hit a lot!
*
* This is a bitmask to keep things small, as this is a recursive
* routine and we don't want to eat up stack space.
*/
unsigned long used; /* for ADD */
/* Thanks to this running after a simplify, we don't need to iterate
* down through IDENTs or handle SUB.
*
* We scan for a single symrec, gathering info along the way. After
* we've found the symrec, we keep scanning but error if we find
* another one. We pull out the single symrec and any legal operations
* performed on it.
*
* Also, if we find a float anywhere, we don't allow mixing of a single
* symrec with it.
*/
switch (e->op) {
case YASM_EXPR_ADD:
/* Okay for single symrec anywhere in expr.
* Check for single symrec anywhere.
* Handle symrec-symrec by checking for (-1*symrec)
* and symrec term pairs (where both symrecs are in the same
* segment).
*/
if (e->numterms > 32)
yasm__fatal(N_("expression on line %d has too many add terms;"
" internal limit of 32"), e->line);
used = 0;
for (i=0; i<e->numterms; i++) {
int j;
yasm_expr *sube;
yasm_intnum *intn;
yasm_symrec *sym;
/*@dependent@*/ yasm_section *sect2;
/*@dependent@*/ /*@null@*/ yasm_bytecode *precbc2;
/* First look for an (-1*symrec) term */
if (e->terms[i].type != YASM_EXPR_EXPR)
continue;
sube = e->terms[i].data.expn;
if (sube->op != YASM_EXPR_MUL || sube->numterms != 2) {
/* recurse instead */
if (value_finalize_scan(value, sube, expr_precbc,
ssym_not_ok))
return 1;
continue;
}
if (sube->terms[0].type == YASM_EXPR_INT &&
sube->terms[1].type == YASM_EXPR_SYM) {
intn = sube->terms[0].data.intn;
sym = sube->terms[1].data.sym;
} else if (sube->terms[0].type == YASM_EXPR_SYM &&
sube->terms[1].type == YASM_EXPR_INT) {
sym = sube->terms[0].data.sym;
intn = sube->terms[1].data.intn;
} else {
if (value_finalize_scan(value, sube, expr_precbc,
ssym_not_ok))
return 1;
continue;
}
if (!yasm_intnum_is_neg1(intn)) {
if (value_finalize_scan(value, sube, expr_precbc,
ssym_not_ok))
return 1;
continue;
}
/* Look for the same symrec term; even if both are external,
* they should cancel out.
*/
for (j=0; j<e->numterms; j++) {
if (e->terms[j].type == YASM_EXPR_SYM
&& e->terms[j].data.sym == sym
&& (used & (1<<j)) == 0) {
/* Mark as used */
used |= 1<<j;
/* Replace both symrec portions with 0 */
yasm_expr_destroy(sube);
e->terms[i].type = YASM_EXPR_INT;
e->terms[i].data.intn = yasm_intnum_create_uint(0);
e->terms[j].type = YASM_EXPR_INT;
e->terms[j].data.intn = yasm_intnum_create_uint(0);
break; /* stop looking */
}
}
if (j != e->numterms)
continue;
if (!yasm_symrec_get_label(sym, &precbc)) {
if (value_finalize_scan(value, sube, expr_precbc,
ssym_not_ok))
return 1;
continue;
}
sect2 = yasm_bc_get_section(precbc);
/* Now look for a unused symrec term in the same segment */
for (j=0; j<e->numterms; j++) {
if (e->terms[j].type == YASM_EXPR_SYM
&& yasm_symrec_get_label(e->terms[j].data.sym,
&precbc2)
&& (sect = yasm_bc_get_section(precbc2))
&& sect == sect2
&& (used & (1<<j)) == 0) {
/* Mark as used */
used |= 1<<j;
break; /* stop looking */
}
}
/* We didn't match in the same segment. If the
* -1*symrec is actually -1*curpos, we can match
* unused symrec terms in other segments and generate
* a curpos-relative reloc.
*
* Similarly, handle -1*symrec in other segment via the
* following transformation:
* other-this = (other-.)+(.-this)
* We can only do this transformation if "this" is in
* this expr's segment.
*
* Don't do this if we've already become curpos-relative.
* The unmatched symrec will be caught below.
*/
if (j == e->numterms && !value->curpos_rel
&& (yasm_symrec_is_curpos(sym)
|| (expr_precbc
&& sect2 == yasm_bc_get_section(expr_precbc)))) {
for (j=0; j<e->numterms; j++) {
if (e->terms[j].type == YASM_EXPR_SYM
&& !yasm_symrec_get_equ(e->terms[j].data.sym)
&& !yasm_symrec_is_special(e->terms[j].data.sym)
&& (used & (1<<j)) == 0) {
/* Mark as used */
used |= 1<<j;
/* Mark value as curpos-relative */
if (value->rel || ssym_not_ok)
return 1;
value->rel = e->terms[j].data.sym;
value->curpos_rel = 1;
if (yasm_symrec_is_curpos(sym)) {
/* Replace both symrec portions with 0 */
yasm_expr_destroy(sube);
e->terms[i].type = YASM_EXPR_INT;
e->terms[i].data.intn =
yasm_intnum_create_uint(0);
e->terms[j].type = YASM_EXPR_INT;
e->terms[j].data.intn =
yasm_intnum_create_uint(0);
} else {
/* Replace positive portion with curpos */
yasm_object *object =
yasm_section_get_object(sect2);
yasm_symtab *symtab = object->symtab;
e->terms[j].data.sym =
yasm_symtab_define_curpos
(symtab, ".", expr_precbc, e->line);
}
break; /* stop looking */
}
}
}
if (j == e->numterms)
return 1; /* We didn't find a match! */
}
/* Look for unmatched symrecs. If we've already found one or
* we don't WANT to find one, error out.
*/
for (i=0; i<e->numterms; i++) {
if (e->terms[i].type == YASM_EXPR_SYM
&& (used & (1<<i)) == 0) {
if (value->rel || ssym_not_ok)
return 1;
value->rel = e->terms[i].data.sym;
/* and replace with 0 */
e->terms[i].type = YASM_EXPR_INT;
e->terms[i].data.intn = yasm_intnum_create_uint(0);
}
}
break;
case YASM_EXPR_SHR:
/* Okay for single symrec in LHS and constant on RHS.
* Single symrecs are not okay on RHS.
* If RHS is non-constant, don't allow single symrec on LHS.
* XXX: should rshift be an expr instead??
*/
/* Check for single sym on LHS */
if (e->terms[0].type != YASM_EXPR_SYM)
break;
/* If we already have a sym, we can't take another one */
if (value->rel || ssym_not_ok)
return 1;
/* RHS must be a positive integer */
if (e->terms[1].type != YASM_EXPR_INT)
return 1; /* can't shift sym by non-constant integer */
shamt = yasm_intnum_get_uint(e->terms[1].data.intn);
if ((shamt + value->rshift) > YASM_VALUE_RSHIFT_MAX)
return 1; /* total shift would be too large */
/* Update value */
value->rshift += shamt;
value->rel = e->terms[0].data.sym;
/* Replace symbol with 0 */
e->terms[0].type = YASM_EXPR_INT;
e->terms[0].data.intn = yasm_intnum_create_uint(0);
/* Just leave SHR in place */
break;
case YASM_EXPR_SEG:
/* Okay for single symrec (can only be done once).
* Not okay for anything BUT a single symrec as an immediate
* child.
*/
if (e->terms[0].type != YASM_EXPR_SYM)
return 1;
if (value->seg_of)
return 1; /* multiple SEG not legal */
value->seg_of = 1;
if (value->rel || ssym_not_ok)
return 1; /* got a relative portion somewhere else? */
value->rel = e->terms[0].data.sym;
/* replace with ident'ed 0 */
e->op = YASM_EXPR_IDENT;
e->terms[0].type = YASM_EXPR_INT;
e->terms[0].data.intn = yasm_intnum_create_uint(0);
break;
case YASM_EXPR_WRT:
/* Okay for single symrec in LHS and either a register or single
* symrec (as an immediate child) on RHS.
* If a single symrec on RHS, can only be done once.
* WRT reg is left in expr for arch to look at.
*/
/* Handle RHS */
switch (e->terms[1].type) {
case YASM_EXPR_SYM:
if (value->wrt)
return 1;
value->wrt = e->terms[1].data.sym;
/* and drop the WRT portion */
e->op = YASM_EXPR_IDENT;
e->numterms = 1;
break;
case YASM_EXPR_REG:
break; /* ignore */
default:
return 1;
}
/* Handle LHS */
switch (e->terms[0].type) {
case YASM_EXPR_SYM:
if (value->rel || ssym_not_ok)
return 1;
value->rel = e->terms[0].data.sym;
/* and replace with 0 */
e->terms[0].type = YASM_EXPR_INT;
e->terms[0].data.intn = yasm_intnum_create_uint(0);
break;
case YASM_EXPR_EXPR:
/* recurse */
return value_finalize_scan(value, e->terms[0].data.expn,
expr_precbc, ssym_not_ok);
default:
break; /* ignore */
}
break;
default:
/* Single symrec not allowed anywhere */
for (i=0; i<e->numterms; i++) {
switch (e->terms[i].type) {
case YASM_EXPR_SYM:
return 1;
case YASM_EXPR_EXPR:
/* recurse */
return value_finalize_scan(value,
e->terms[i].data.expn,
expr_precbc, 1);
default:
break;
}
}
break;
}
return 0;
}
static int
xdf_objfmt_output_sym(yasm_symrec *sym, /*@null@*/ void *d)
{
/*@null@*/ xdf_objfmt_output_info *info = (xdf_objfmt_output_info *)d;
yasm_sym_vis vis = yasm_symrec_get_visibility(sym);
assert(info != NULL);
if (info->all_syms || vis != YASM_SYM_LOCAL) {
/*@only@*/ char *name = yasm_symrec_get_global_name(sym, info->object);
const yasm_expr *equ_val;
const yasm_intnum *intn;
size_t len = strlen(name);
unsigned long value = 0;
long scnum = -3; /* -3 = debugging symbol */
/*@dependent@*/ /*@null@*/ yasm_section *sect;
/*@dependent@*/ /*@null@*/ yasm_bytecode *precbc;
unsigned long flags = 0;
unsigned char *localbuf;
if (vis & YASM_SYM_GLOBAL)
flags = XDF_SYM_GLOBAL;
/* Look at symrec for value/scnum/etc. */
if (yasm_symrec_get_label(sym, &precbc)) {
if (precbc)
sect = yasm_bc_get_section(precbc);
else
sect = NULL;
/* it's a label: get value and offset.
* If there is not a section, leave as debugging symbol.
*/
if (sect) {
/*@dependent@*/ /*@null@*/ xdf_section_data *csectd;
csectd = yasm_section_get_data(sect, &xdf_section_data_cb);
if (csectd)
scnum = csectd->scnum;
else
yasm_internal_error(N_("didn't understand section"));
if (precbc)
value += yasm_bc_next_offset(precbc);
}
} else if ((equ_val = yasm_symrec_get_equ(sym))) {
yasm_expr *equ_val_copy = yasm_expr_copy(equ_val);
intn = yasm_expr_get_intnum(&equ_val_copy, 1);
if (!intn) {
if (vis & YASM_SYM_GLOBAL) {
yasm_error_set(YASM_ERROR_NOT_CONSTANT,
N_("global EQU value not an integer expression"));
yasm_errwarn_propagate(info->errwarns, equ_val->line);
}
} else
value = yasm_intnum_get_uint(intn);
yasm_expr_destroy(equ_val_copy);
flags |= XDF_SYM_EQU;
scnum = -2; /* -2 = absolute symbol */
} else {
if (vis & YASM_SYM_EXTERN) {
flags = XDF_SYM_EXTERN;
scnum = -1;
}
}
localbuf = info->buf;
YASM_WRITE_32_L(localbuf, scnum); /* section number */
YASM_WRITE_32_L(localbuf, value); /* value */
YASM_WRITE_32_L(localbuf, info->strtab_offset);
info->strtab_offset += (unsigned long)(len+1);
YASM_WRITE_32_L(localbuf, flags); /* flags */
fwrite(info->buf, 16, 1, info->f);
yasm_xfree(name);
}
return 0;
}
