static AST ifstmt() {
Token *t = &tok;
AST a=0;
AST a1=0,a2=0,a3=0;
if (t->sym == tIF) {
gettoken();
if (t->sym == '(') {
gettoken();
a1 = bexpr();
if (t->sym == ')') gettoken();
else parse_error("expected )");
a2 = stmt();
if (t->sym == tELSE) { /* else is optional */
gettoken();
a3 = stmt();
}
} else {
parse_error("expected (");
}
a = make_AST_if(a1,a2,a3);
} else {
parse_error("expected if");
skiptoken(';');
}
return a;
}
expr *evaluate(scanner sc, void *scprivate, struct tokenval *tv,
int *fwref, int critical, struct eval_hints *hints)
{
expr *e;
expr *f = NULL;
hint = hints;
if (hint)
hint->type = EAH_NOHINT;
if (critical & CRITICAL) {
critical &= ~CRITICAL;
bexpr = rexp0;
} else
bexpr = expr0;
scan = sc;
scpriv = scprivate;
tokval = tv;
opflags = fwref;
if (tokval->t_type == TOKEN_INVALID)
i = scan(scpriv, tokval);
else
i = tokval->t_type;
while (ntempexprs) /* initialize temporary storage */
nasm_free(tempexprs[--ntempexprs]);
e = bexpr(critical);
if (!e)
return NULL;
if (i == TOKEN_WRT) {
i = scan(scpriv, tokval); /* eat the WRT */
f = expr6(critical);
if (!f)
return NULL;
}
e = scalar_mult(e, 1L, false); /* strip far-absolute segment part */
if (f) {
expr *g;
if (is_just_unknown(f))
g = unknown_expr();
else {
int64_t value;
begintemp();
if (!is_reloc(f)) {
nasm_error(ERR_NONFATAL, "invalid right-hand operand to WRT");
return NULL;
}
value = reloc_seg(f);
if (value == NO_SEG)
value = reloc_value(f) | SEG_ABS;
else if (!(value & SEG_ABS) && !(value % 2) && critical) {
nasm_error(ERR_NONFATAL, "invalid right-hand operand to WRT");
return NULL;
}
addtotemp(EXPR_WRT, value);
g = finishtemp();
}
e = add_vectors(e, g);
}
return e;
}
static expr *expr6(int critical)
{
int32_t type;
expr *e;
int32_t label_seg;
int64_t label_ofs;
int64_t tmpval;
bool rn_warn;
char *scope;
switch (i) {
case '-':
i = scan(scpriv, tokval);
e = expr6(critical);
if (!e)
return NULL;
return scalar_mult(e, -1L, false);
case '+':
i = scan(scpriv, tokval);
return expr6(critical);
case '~':
i = scan(scpriv, tokval);
e = expr6(critical);
if (!e)
return NULL;
if (is_just_unknown(e))
return unknown_expr();
else if (!is_simple(e)) {
nasm_error(ERR_NONFATAL, "`~' operator may only be applied to"
" scalar values");
return NULL;
}
return scalarvect(~reloc_value(e));
case '!':
i = scan(scpriv, tokval);
e = expr6(critical);
if (!e)
return NULL;
if (is_just_unknown(e))
return unknown_expr();
else if (!is_simple(e)) {
nasm_error(ERR_NONFATAL, "`!' operator may only be applied to"
" scalar values");
return NULL;
}
return scalarvect(!reloc_value(e));
case TOKEN_IFUNC:
{
enum ifunc func = tokval->t_integer;
i = scan(scpriv, tokval);
e = expr6(critical);
if (!e)
return NULL;
if (is_just_unknown(e))
return unknown_expr();
else if (!is_simple(e)) {
nasm_error(ERR_NONFATAL, "function may only be applied to"
" scalar values");
return NULL;
}
return scalarvect(eval_ifunc(reloc_value(e), func));
}
case TOKEN_SEG:
i = scan(scpriv, tokval);
e = expr6(critical);
if (!e)
return NULL;
e = segment_part(e);
if (!e)
return NULL;
if (is_unknown(e) && critical) {
nasm_error(ERR_NONFATAL, "unable to determine segment base");
return NULL;
}
return e;
case TOKEN_FLOATIZE:
return eval_floatize(tokval->t_integer);
case TOKEN_STRFUNC:
return eval_strfunc(tokval->t_integer);
case '(':
i = scan(scpriv, tokval);
e = bexpr(critical);
if (!e)
return NULL;
if (i != ')') {
nasm_error(ERR_NONFATAL, "expecting `)'");
return NULL;
}
i = scan(scpriv, tokval);
return e;
case TOKEN_NUM:
case TOKEN_STR:
case TOKEN_REG:
case TOKEN_ID:
case TOKEN_INSN: /* Opcodes that occur here are really labels */
case TOKEN_HERE:
case TOKEN_BASE:
case TOKEN_DECORATOR:
begintemp();
switch (i) {
case TOKEN_NUM:
addtotemp(EXPR_SIMPLE, tokval->t_integer);
break;
case TOKEN_STR:
tmpval = readstrnum(tokval->t_charptr, tokval->t_inttwo, &rn_warn);
if (rn_warn)
nasm_error(ERR_WARNING|ERR_PASS1, "character constant too long");
addtotemp(EXPR_SIMPLE, tmpval);
break;
case TOKEN_REG:
addtotemp(tokval->t_integer, 1L);
if (hint && hint->type == EAH_NOHINT)
hint->base = tokval->t_integer, hint->type = EAH_MAKEBASE;
break;
case TOKEN_ID:
case TOKEN_INSN:
case TOKEN_HERE:
case TOKEN_BASE:
/*
* If !location.known, this indicates that no
* symbol, Here or Base references are valid because we
* are in preprocess-only mode.
*/
if (!location.known) {
nasm_error(ERR_NONFATAL,
"%s not supported in preprocess-only mode",
(i == TOKEN_HERE ? "`$'" :
i == TOKEN_BASE ? "`$$'" :
"symbol references"));
addtotemp(EXPR_UNKNOWN, 1L);
break;
}
type = EXPR_SIMPLE; /* might get overridden by UNKNOWN */
if (i == TOKEN_BASE) {
label_seg = in_abs_seg ? abs_seg : location.segment;
label_ofs = 0;
} else if (i == TOKEN_HERE) {
label_seg = in_abs_seg ? abs_seg : location.segment;
label_ofs = in_abs_seg ? abs_offset : location.offset;
} else {
if (!lookup_label(tokval->t_charptr, &label_seg, &label_ofs)) {
scope = local_scope(tokval->t_charptr);
if (critical == 2) {
nasm_error(ERR_NONFATAL, "symbol `%s%s' undefined",
scope,tokval->t_charptr);
return NULL;
} else if (critical == 1) {
nasm_error(ERR_NONFATAL,
"symbol `%s%s' not defined before use",
scope,tokval->t_charptr);
return NULL;
} else {
if (opflags)
*opflags |= OPFLAG_FORWARD;
type = EXPR_UNKNOWN;
label_seg = NO_SEG;
label_ofs = 1;
}
}
if (opflags && is_extern(tokval->t_charptr))
*opflags |= OPFLAG_EXTERN;
}
addtotemp(type, label_ofs);
if (label_seg != NO_SEG)
addtotemp(EXPR_SEGBASE + label_seg, 1L);
break;
case TOKEN_DECORATOR:
addtotemp(EXPR_RDSAE, tokval->t_integer);
break;
}
i = scan(scpriv, tokval);
return finishtemp();
default:
nasm_error(ERR_NONFATAL, "expression syntax error");
return NULL;
}
}
