1 /* ----------------------------------------------------------------------- *
3 * Copyright 1996-2012 The NASM Authors - All Rights Reserved
4 * See the file AUTHORS included with the NASM distribution for
5 * the specific copyright holders.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
19 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
30 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 * ----------------------------------------------------------------------- */
35 * eval.c expression evaluator for the Netwide Assembler
53 #define TEMPEXPRS_DELTA 128
54 #define TEMPEXPR_DELTA 8
56 static scanner scan; /* Address of scanner routine */
57 static efunc error; /* Address of error reporting routine */
58 static lfunc labelfunc; /* Address of label routine */
60 static struct ofmt *outfmt; /* Structure of addresses of output routines */
62 static expr **tempexprs = NULL;
63 static int ntempexprs;
64 static int tempexprs_size = 0;
66 static expr *tempexpr;
68 static int tempexpr_size;
70 static struct tokenval *tokval; /* The current token */
71 static int i; /* The t_type of tokval */
74 static struct location *location; /* Pointer to current line's segment,offset */
77 static struct eval_hints *hint;
79 extern int in_abs_seg; /* ABSOLUTE segment flag */
80 extern int32_t abs_seg; /* ABSOLUTE segment */
81 extern int32_t abs_offset; /* ABSOLUTE segment offset */
84 * Unimportant cleanup is done to avoid confusing people who are trying
85 * to debug real memory leaks
87 void eval_cleanup(void)
90 nasm_free(tempexprs[--ntempexprs]);
95 * Construct a temporary expression.
97 static void begintemp(void)
100 tempexpr_size = ntempexpr = 0;
103 static void addtotemp(int32_t type, int64_t value)
105 while (ntempexpr >= tempexpr_size) {
106 tempexpr_size += TEMPEXPR_DELTA;
107 tempexpr = nasm_realloc(tempexpr,
108 tempexpr_size * sizeof(*tempexpr));
110 tempexpr[ntempexpr].type = type;
111 tempexpr[ntempexpr++].value = value;
114 static expr *finishtemp(void)
116 addtotemp(0L, 0L); /* terminate */
117 while (ntempexprs >= tempexprs_size) {
118 tempexprs_size += TEMPEXPRS_DELTA;
119 tempexprs = nasm_realloc(tempexprs,
120 tempexprs_size * sizeof(*tempexprs));
122 return tempexprs[ntempexprs++] = tempexpr;
126 * Add two vector datatypes. We have some bizarre behaviour on far-
127 * absolute segment types: we preserve them during addition _only_
128 * if one of the segments is a truly pure scalar.
130 static expr *add_vectors(expr * p, expr * q)
134 preserve = is_really_simple(p) || is_really_simple(q);
138 while (p->type && q->type &&
139 p->type < EXPR_SEGBASE + SEG_ABS &&
140 q->type < EXPR_SEGBASE + SEG_ABS) {
143 if (p->type > q->type) {
144 addtotemp(q->type, q->value);
145 lasttype = q++->type;
146 } else if (p->type < q->type) {
147 addtotemp(p->type, p->value);
148 lasttype = p++->type;
149 } else { /* *p and *q have same type */
150 int64_t sum = p->value + q->value;
152 addtotemp(p->type, sum);
154 hint->type = EAH_SUMMED;
159 if (lasttype == EXPR_UNKNOWN) {
163 while (p->type && (preserve || p->type < EXPR_SEGBASE + SEG_ABS)) {
164 addtotemp(p->type, p->value);
167 while (q->type && (preserve || q->type < EXPR_SEGBASE + SEG_ABS)) {
168 addtotemp(q->type, q->value);
176 * Multiply a vector by a scalar. Strip far-absolute segment part
179 * Explicit treatment of UNKNOWN is not required in this routine,
180 * since it will silently do the Right Thing anyway.
182 * If `affect_hints' is set, we also change the hint type to
183 * NOTBASE if a MAKEBASE hint points at a register being
184 * multiplied. This allows [eax*1+ebx] to hint EBX rather than EAX
185 * as the base register.
187 static expr *scalar_mult(expr * vect, int64_t scalar, int affect_hints)
191 while (p->type && p->type < EXPR_SEGBASE + SEG_ABS) {
192 p->value = scalar * (p->value);
193 if (hint && hint->type == EAH_MAKEBASE &&
194 p->type == hint->base && affect_hints)
195 hint->type = EAH_NOTBASE;
203 static expr *scalarvect(int64_t scalar)
206 addtotemp(EXPR_SIMPLE, scalar);
210 static expr *unknown_expr(void)
213 addtotemp(EXPR_UNKNOWN, 1L);
218 * The SEG operator: calculate the segment part of a relocatable
219 * value. Return NULL, as usual, if an error occurs. Report the
222 static expr *segment_part(expr * e)
227 return unknown_expr();
230 error(ERR_NONFATAL, "cannot apply SEG to a non-relocatable value");
236 error(ERR_NONFATAL, "cannot apply SEG to a non-relocatable value");
238 } else if (seg & SEG_ABS) {
239 return scalarvect(seg & ~SEG_ABS);
240 } else if (seg & 1) {
241 error(ERR_NONFATAL, "SEG applied to something which"
242 " is already a segment base");
245 int32_t base = outfmt->segbase(seg + 1);
248 addtotemp((base == NO_SEG ? EXPR_UNKNOWN : EXPR_SEGBASE + base),
255 * Recursive-descent parser. Called with a single boolean operand,
256 * which is true if the evaluation is critical (i.e. unresolved
257 * symbols are an error condition). Must update the global `i' to
258 * reflect the token after the parsed string. May return NULL.
260 * evaluate() should report its own errors: on return it is assumed
261 * that if NULL has been returned, the error has already been
268 * expr : bexpr [ WRT expr6 ]
269 * bexpr : rexp0 or expr0 depending on relative-mode setting
270 * rexp0 : rexp1 [ {||} rexp1...]
271 * rexp1 : rexp2 [ {^^} rexp2...]
272 * rexp2 : rexp3 [ {&&} rexp3...]
273 * rexp3 : expr0 [ {=,==,<>,!=,<,>,<=,>=} expr0 ]
274 * expr0 : expr1 [ {|} expr1...]
275 * expr1 : expr2 [ {^} expr2...]
276 * expr2 : expr3 [ {&} expr3...]
277 * expr3 : expr4 [ {<<,>>} expr4...]
278 * expr4 : expr5 [ {+,-} expr5...]
279 * expr5 : expr6 [ {*,/,%,//,%%} expr6...]
280 * expr6 : { ~,+,-,IFUNC,SEG } expr6
287 static expr *rexp0(int), *rexp1(int), *rexp2(int), *rexp3(int);
289 static expr *expr0(int), *expr1(int), *expr2(int), *expr3(int);
290 static expr *expr4(int), *expr5(int), *expr6(int);
292 static expr *(*bexpr) (int);
294 static expr *rexp0(int critical)
302 while (i == TOKEN_DBL_OR) {
303 i = scan(scpriv, tokval);
307 if (!(is_simple(e) || is_just_unknown(e)) ||
308 !(is_simple(f) || is_just_unknown(f))) {
309 error(ERR_NONFATAL, "`|' operator may only be applied to"
313 if (is_just_unknown(e) || is_just_unknown(f))
316 e = scalarvect((int64_t)(reloc_value(e) || reloc_value(f)));
321 static expr *rexp1(int critical)
329 while (i == TOKEN_DBL_XOR) {
330 i = scan(scpriv, tokval);
334 if (!(is_simple(e) || is_just_unknown(e)) ||
335 !(is_simple(f) || is_just_unknown(f))) {
336 error(ERR_NONFATAL, "`^' operator may only be applied to"
340 if (is_just_unknown(e) || is_just_unknown(f))
343 e = scalarvect((int64_t)(!reloc_value(e) ^ !reloc_value(f)));
348 static expr *rexp2(int critical)
355 while (i == TOKEN_DBL_AND) {
356 i = scan(scpriv, tokval);
360 if (!(is_simple(e) || is_just_unknown(e)) ||
361 !(is_simple(f) || is_just_unknown(f))) {
362 error(ERR_NONFATAL, "`&' operator may only be applied to"
365 if (is_just_unknown(e) || is_just_unknown(f))
368 e = scalarvect((int64_t)(reloc_value(e) && reloc_value(f)));
373 static expr *rexp3(int critical)
382 while (i == TOKEN_EQ || i == TOKEN_LT || i == TOKEN_GT ||
383 i == TOKEN_NE || i == TOKEN_LE || i == TOKEN_GE) {
385 i = scan(scpriv, tokval);
390 e = add_vectors(e, scalar_mult(f, -1L, false));
396 v = -1; /* means unknown */
397 else if (!is_really_simple(e) || reloc_value(e) != 0)
398 v = (j == TOKEN_NE); /* unequal, so return true if NE */
400 v = (j == TOKEN_EQ); /* equal, so return true if EQ */
404 v = -1; /* means unknown */
405 else if (!is_really_simple(e)) {
407 "`%s': operands differ by a non-scalar",
408 (j == TOKEN_LE ? "<=" : j == TOKEN_LT ? "<" : j ==
409 TOKEN_GE ? ">=" : ">"));
410 v = 0; /* must set it to _something_ */
412 int64_t vv = reloc_value(e);
414 v = (j == TOKEN_LE || j == TOKEN_GE);
416 v = (j == TOKEN_GE || j == TOKEN_GT);
418 v = (j == TOKEN_LE || j == TOKEN_LT);
431 static expr *expr0(int critical)
440 i = scan(scpriv, tokval);
444 if (!(is_simple(e) || is_just_unknown(e)) ||
445 !(is_simple(f) || is_just_unknown(f))) {
446 error(ERR_NONFATAL, "`|' operator may only be applied to"
449 if (is_just_unknown(e) || is_just_unknown(f))
452 e = scalarvect(reloc_value(e) | reloc_value(f));
457 static expr *expr1(int critical)
466 i = scan(scpriv, tokval);
470 if (!(is_simple(e) || is_just_unknown(e)) ||
471 !(is_simple(f) || is_just_unknown(f))) {
472 error(ERR_NONFATAL, "`^' operator may only be applied to"
475 if (is_just_unknown(e) || is_just_unknown(f))
478 e = scalarvect(reloc_value(e) ^ reloc_value(f));
483 static expr *expr2(int critical)
492 i = scan(scpriv, tokval);
496 if (!(is_simple(e) || is_just_unknown(e)) ||
497 !(is_simple(f) || is_just_unknown(f))) {
498 error(ERR_NONFATAL, "`&' operator may only be applied to"
501 if (is_just_unknown(e) || is_just_unknown(f))
504 e = scalarvect(reloc_value(e) & reloc_value(f));
509 static expr *expr3(int critical)
517 while (i == TOKEN_SHL || i == TOKEN_SHR) {
519 i = scan(scpriv, tokval);
523 if (!(is_simple(e) || is_just_unknown(e)) ||
524 !(is_simple(f) || is_just_unknown(f))) {
525 error(ERR_NONFATAL, "shift operator may only be applied to"
527 } else if (is_just_unknown(e) || is_just_unknown(f)) {
532 e = scalarvect(reloc_value(e) << reloc_value(f));
535 e = scalarvect(((uint64_t)reloc_value(e)) >>
543 static expr *expr4(int critical)
550 while (i == '+' || i == '-') {
552 i = scan(scpriv, tokval);
558 e = add_vectors(e, f);
561 e = add_vectors(e, scalar_mult(f, -1L, false));
568 static expr *expr5(int critical)
575 while (i == '*' || i == '/' || i == '%' ||
576 i == TOKEN_SDIV || i == TOKEN_SMOD) {
578 i = scan(scpriv, tokval);
582 if (j != '*' && (!(is_simple(e) || is_just_unknown(e)) ||
583 !(is_simple(f) || is_just_unknown(f)))) {
584 error(ERR_NONFATAL, "division operator may only be applied to"
588 if (j != '*' && !is_unknown(f) && reloc_value(f) == 0) {
589 error(ERR_NONFATAL, "division by zero");
595 e = scalar_mult(f, reloc_value(e), true);
596 else if (is_simple(f))
597 e = scalar_mult(e, reloc_value(f), true);
598 else if (is_just_unknown(e) && is_just_unknown(f))
601 error(ERR_NONFATAL, "unable to multiply two "
602 "non-scalar objects");
607 if (is_just_unknown(e) || is_just_unknown(f))
610 e = scalarvect(((uint64_t)reloc_value(e)) /
611 ((uint64_t)reloc_value(f)));
614 if (is_just_unknown(e) || is_just_unknown(f))
617 e = scalarvect(((uint64_t)reloc_value(e)) %
618 ((uint64_t)reloc_value(f)));
621 if (is_just_unknown(e) || is_just_unknown(f))
624 e = scalarvect(((int64_t)reloc_value(e)) /
625 ((int64_t)reloc_value(f)));
628 if (is_just_unknown(e) || is_just_unknown(f))
631 e = scalarvect(((int64_t)reloc_value(e)) %
632 ((int64_t)reloc_value(f)));
639 static expr *eval_floatize(enum floatize type)
641 uint8_t result[16], *p; /* Up to 128 bits */
642 static const struct {
643 int bytes, start, len;
645 { 1, 0, 1 }, /* FLOAT_8 */
646 { 2, 0, 2 }, /* FLOAT_16 */
647 { 4, 0, 4 }, /* FLOAT_32 */
648 { 8, 0, 8 }, /* FLOAT_64 */
649 { 10, 0, 8 }, /* FLOAT_80M */
650 { 10, 8, 2 }, /* FLOAT_80E */
651 { 16, 0, 8 }, /* FLOAT_128L */
652 { 16, 8, 8 }, /* FLOAT_128H */
658 i = scan(scpriv, tokval);
660 error(ERR_NONFATAL, "expecting `('");
663 i = scan(scpriv, tokval);
664 if (i == '-' || i == '+') {
665 sign = (i == '-') ? -1 : 1;
666 i = scan(scpriv, tokval);
668 if (i != TOKEN_FLOAT) {
669 error(ERR_NONFATAL, "expecting floating-point number");
672 if (!float_const(tokval->t_charptr, sign, result,
673 formats[type].bytes, error))
675 i = scan(scpriv, tokval);
677 error(ERR_NONFATAL, "expecting `)'");
681 p = result+formats[type].start+formats[type].len;
683 for (j = formats[type].len; j; j--) {
685 val = (val << 8) + *p;
689 addtotemp(EXPR_SIMPLE, val);
691 i = scan(scpriv, tokval);
695 static expr *eval_strfunc(enum strfunc type)
700 bool parens, rn_warn;
703 i = scan(scpriv, tokval);
706 i = scan(scpriv, tokval);
708 if (i != TOKEN_STR) {
709 error(ERR_NONFATAL, "expecting string");
712 string_len = string_transform(tokval->t_charptr, tokval->t_inttwo,
714 if (string_len == (size_t)-1) {
715 error(ERR_NONFATAL, "invalid string for transform");
719 val = readstrnum(string, string_len, &rn_warn);
721 i = scan(scpriv, tokval);
723 error(ERR_NONFATAL, "expecting `)'");
729 error(ERR_WARNING|ERR_PASS1, "character constant too long");
732 addtotemp(EXPR_SIMPLE, val);
734 i = scan(scpriv, tokval);
738 static int64_t eval_ifunc(int64_t val, enum ifunc func)
741 uint64_t uval = (uint64_t)val;
747 errtype = (func == IFUNC_ILOG2E) ? ERR_NONFATAL : ERR_WARNING;
749 if (!is_power2(uval))
750 error(errtype, "ilog2 argument is not a power of two");
757 rv = (uval < 2) ? 0 : ilog2_64(uval-1) + 1;
761 error(ERR_PANIC, "invalid IFUNC token %d", func);
769 static expr *expr6(int critical)
781 i = scan(scpriv, tokval);
785 return scalar_mult(e, -1L, false);
788 i = scan(scpriv, tokval);
789 return expr6(critical);
792 i = scan(scpriv, tokval);
796 if (is_just_unknown(e))
797 return unknown_expr();
798 else if (!is_simple(e)) {
799 error(ERR_NONFATAL, "`~' operator may only be applied to"
803 return scalarvect(~reloc_value(e));
806 i = scan(scpriv, tokval);
810 if (is_just_unknown(e))
811 return unknown_expr();
812 else if (!is_simple(e)) {
813 error(ERR_NONFATAL, "`!' operator may only be applied to"
817 return scalarvect(!reloc_value(e));
821 enum ifunc func = tokval->t_integer;
822 i = scan(scpriv, tokval);
826 if (is_just_unknown(e))
827 return unknown_expr();
828 else if (!is_simple(e)) {
829 error(ERR_NONFATAL, "function may only be applied to"
833 return scalarvect(eval_ifunc(reloc_value(e), func));
837 i = scan(scpriv, tokval);
844 if (is_unknown(e) && critical) {
845 error(ERR_NONFATAL, "unable to determine segment base");
851 return eval_floatize(tokval->t_integer);
854 return eval_strfunc(tokval->t_integer);
857 i = scan(scpriv, tokval);
862 error(ERR_NONFATAL, "expecting `)'");
865 i = scan(scpriv, tokval);
872 case TOKEN_INSN: /* Opcodes that occur here are really labels */
875 case TOKEN_DECORATOR:
879 addtotemp(EXPR_SIMPLE, tokval->t_integer);
882 tmpval = readstrnum(tokval->t_charptr, tokval->t_inttwo, &rn_warn);
884 error(ERR_WARNING|ERR_PASS1, "character constant too long");
885 addtotemp(EXPR_SIMPLE, tmpval);
888 addtotemp(tokval->t_integer, 1L);
889 if (hint && hint->type == EAH_NOHINT)
890 hint->base = tokval->t_integer, hint->type = EAH_MAKEBASE;
897 * If !location->known, this indicates that no
898 * symbol, Here or Base references are valid because we
899 * are in preprocess-only mode.
901 if (!location->known) {
903 "%s not supported in preprocess-only mode",
904 (i == TOKEN_HERE ? "`$'" :
905 i == TOKEN_BASE ? "`$$'" :
906 "symbol references"));
907 addtotemp(EXPR_UNKNOWN, 1L);
911 type = EXPR_SIMPLE; /* might get overridden by UNKNOWN */
912 if (i == TOKEN_BASE) {
913 label_seg = in_abs_seg ? abs_seg : location->segment;
915 } else if (i == TOKEN_HERE) {
916 label_seg = in_abs_seg ? abs_seg : location->segment;
917 label_ofs = in_abs_seg ? abs_offset : location->offset;
919 if (!labelfunc(tokval->t_charptr, &label_seg, &label_ofs)) {
920 scope = local_scope(tokval->t_charptr);
922 error(ERR_NONFATAL, "symbol `%s%s' undefined",
923 scope,tokval->t_charptr);
925 } else if (critical == 1) {
927 "symbol `%s%s' not defined before use",
928 scope,tokval->t_charptr);
932 *opflags |= OPFLAG_FORWARD;
938 if (opflags && is_extern(tokval->t_charptr))
939 *opflags |= OPFLAG_EXTERN;
941 addtotemp(type, label_ofs);
942 if (label_seg != NO_SEG)
943 addtotemp(EXPR_SEGBASE + label_seg, 1L);
945 case TOKEN_DECORATOR:
946 addtotemp(EXPR_RDSAE, tokval->t_integer);
949 i = scan(scpriv, tokval);
953 error(ERR_NONFATAL, "expression syntax error");
958 void eval_global_info(struct ofmt *output, lfunc lookup_label,
959 struct location * locp)
962 labelfunc = lookup_label;
966 expr *evaluate(scanner sc, void *scprivate, struct tokenval *tv,
967 int *fwref, int critical, efunc report_error,
968 struct eval_hints *hints)
975 hint->type = EAH_NOHINT;
977 if (critical & CRITICAL) {
978 critical &= ~CRITICAL;
986 error = report_error;
989 if (tokval->t_type == TOKEN_INVALID)
990 i = scan(scpriv, tokval);
994 while (ntempexprs) /* initialize temporary storage */
995 nasm_free(tempexprs[--ntempexprs]);
1001 if (i == TOKEN_WRT) {
1002 i = scan(scpriv, tokval); /* eat the WRT */
1003 f = expr6(critical);
1007 e = scalar_mult(e, 1L, false); /* strip far-absolute segment part */
1010 if (is_just_unknown(f))
1016 error(ERR_NONFATAL, "invalid right-hand operand to WRT");
1019 value = reloc_seg(f);
1020 if (value == NO_SEG)
1021 value = reloc_value(f) | SEG_ABS;
1022 else if (!(value & SEG_ABS) && !(value % 2) && critical) {
1023 error(ERR_NONFATAL, "invalid right-hand operand to WRT");
1026 addtotemp(EXPR_WRT, value);
1029 e = add_vectors(e, g);