mirror/nasm
2
0
Fork 0
mirror of https://github.com/netwide-assembler/nasm.git synced 2024-12-15 09:09:58 +08:00
Code Issues Packages Projects Releases Wiki Activity
fd14310469
nasm/asm/parser.c
Cyrill Gorcunov a28c40d546 parser: Fix sigsegv on certain equ instruction parsing 
We should check for bounds when accessing nasm_reg_flags.
Seems this bug was for long time already.

https://bugzilla.nasm.us/show_bug.cgi?id=3392516

Reported-by: Jordan Zebor <j.zebor@f5.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
2018-10-13 18:10:30 +03:00

1209 lines
41 KiB
C
Raw Blame History

/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2018 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ----------------------------------------------------------------------- */
/*
* parser.c source line parser for the Netwide Assembler
*/
#include "compiler.h"
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <ctype.h>
#include "nasm.h"
#include "insns.h"
#include "nasmlib.h"
#include "error.h"
#include "stdscan.h"
#include "eval.h"
#include "parser.h"
#include "float.h"
#include "assemble.h"
#include "tables.h"
static int is_comma_next(void);
static struct tokenval tokval;
static int prefix_slot(int prefix)
{
switch (prefix) {
case P_WAIT:
return PPS_WAIT;
case R_CS:
case R_DS:
case R_SS:
case R_ES:
case R_FS:
case R_GS:
return PPS_SEG;
case P_LOCK:
return PPS_LOCK;
case P_REP:
case P_REPE:
case P_REPZ:
case P_REPNE:
case P_REPNZ:
case P_XACQUIRE:
case P_XRELEASE:
case P_BND:
case P_NOBND:
return PPS_REP;
case P_O16:
case P_O32:
case P_O64:
case P_OSP:
return PPS_OSIZE;
case P_A16:
case P_A32:
case P_A64:
case P_ASP:
return PPS_ASIZE;
case P_EVEX:
case P_VEX3:
case P_VEX2:
return PPS_VEX;
default:
nasm_panic(0, "Invalid value %d passed to prefix_slot()", prefix);
return -1;
}
}
static void process_size_override(insn *result, operand *op)
{
if (tasm_compatible_mode) {
switch (tokval.t_integer) {
/* For TASM compatibility a size override inside the
* brackets changes the size of the operand, not the
* address type of the operand as it does in standard
* NASM syntax. Hence:
*
* mov eax,[DWORD val]
*
* is valid syntax in TASM compatibility mode. Note that
* you lose the ability to override the default address
* type for the instruction, but we never use anything
* but 32-bit flat model addressing in our code.
*/
case S_BYTE:
op->type |= BITS8;
break;
case S_WORD:
op->type |= BITS16;
break;
case S_DWORD:
case S_LONG:
op->type |= BITS32;
break;
case S_QWORD:
op->type |= BITS64;
break;
case S_TWORD:
op->type |= BITS80;
break;
case S_OWORD:
op->type |= BITS128;
break;
default:
nasm_error(ERR_NONFATAL,
"invalid operand size specification");
break;
}
} else {
/* Standard NASM compatible syntax */
switch (tokval.t_integer) {
case S_NOSPLIT:
op->eaflags |= EAF_TIMESTWO;
break;
case S_REL:
op->eaflags |= EAF_REL;
break;
case S_ABS:
op->eaflags |= EAF_ABS;
break;
case S_BYTE:
op->disp_size = 8;
op->eaflags |= EAF_BYTEOFFS;
break;
case P_A16:
case P_A32:
case P_A64:
if (result->prefixes[PPS_ASIZE] &&
result->prefixes[PPS_ASIZE] != tokval.t_integer)
nasm_error(ERR_NONFATAL,
"conflicting address size specifications");
else
result->prefixes[PPS_ASIZE] = tokval.t_integer;
break;
case S_WORD:
op->disp_size = 16;
op->eaflags |= EAF_WORDOFFS;
break;
case S_DWORD:
case S_LONG:
op->disp_size = 32;
op->eaflags |= EAF_WORDOFFS;
break;
case S_QWORD:
op->disp_size = 64;
op->eaflags |= EAF_WORDOFFS;
break;
default:
nasm_error(ERR_NONFATAL, "invalid size specification in"
" effective address");
break;
}
}
}
/*
* Brace decorators are are parsed here. opmask and zeroing
* decorators can be placed in any order. e.g. zmm1 {k2}{z} or zmm2
* {z}{k3} decorator(s) are placed at the end of an operand.
*/
static bool parse_braces(decoflags_t *decoflags)
{
int i, j;
i = tokval.t_type;
while (true) {
switch (i) {
case TOKEN_OPMASK:
if (*decoflags & OPMASK_MASK) {
nasm_error(ERR_NONFATAL,
"opmask k%"PRIu64" is already set",
*decoflags & OPMASK_MASK);
*decoflags &= ~OPMASK_MASK;
}
*decoflags |= VAL_OPMASK(nasm_regvals[tokval.t_integer]);
break;
case TOKEN_DECORATOR:
j = tokval.t_integer;
switch (j) {
case BRC_Z:
*decoflags |= Z_MASK;
break;
case BRC_1TO2:
case BRC_1TO4:
case BRC_1TO8:
case BRC_1TO16:
*decoflags |= BRDCAST_MASK | VAL_BRNUM(j - BRC_1TO2);
break;
default:
nasm_error(ERR_NONFATAL,
"{%s} is not an expected decorator",
tokval.t_charptr);
break;
}
break;
case ',':
case TOKEN_EOS:
return false;
default:
nasm_error(ERR_NONFATAL,
"only a series of valid decorators expected");
return true;
}
i = stdscan(NULL, &tokval);
}
}
static int parse_mref(operand *op, const expr *e)
{
int b, i, s; /* basereg, indexreg, scale */
int64_t o; /* offset */
b = i = -1;
o = s = 0;
op->segment = op->wrt = NO_SEG;
if (e->type && e->type <= EXPR_REG_END) { /* this bit's a register */
bool is_gpr = is_class(REG_GPR,nasm_reg_flags[e->type]);
if (is_gpr && e->value == 1)
b = e->type; /* It can be basereg */
else /* No, it has to be indexreg */
i = e->type, s = e->value;
e++;
}
if (e->type && e->type <= EXPR_REG_END) { /* it's a 2nd register */
bool is_gpr = is_class(REG_GPR,nasm_reg_flags[e->type]);
if (b != -1) /* If the first was the base, ... */
i = e->type, s = e->value; /* second has to be indexreg */
else if (!is_gpr || e->value != 1) {
/* If both want to be index */
nasm_error(ERR_NONFATAL,
"invalid effective address: two index registers");
return -1;
} else
b = e->type;
e++;
}
if (e->type) { /* is there an offset? */
if (e->type <= EXPR_REG_END) { /* in fact, is there an error? */
nasm_error(ERR_NONFATAL,
"invalid effective address: impossible register");
return -1;
} else {
if (e->type == EXPR_UNKNOWN) {
op->opflags |= OPFLAG_UNKNOWN;
o = 0; /* doesn't matter what */
while (e->type)
e++; /* go to the end of the line */
} else {
if (e->type == EXPR_SIMPLE) {
o = e->value;
e++;
}
if (e->type == EXPR_WRT) {
op->wrt = e->value;
e++;
}
/*
* Look for a segment base type.
*/
for (; e->type; e++) {
if (!e->value)
continue;
if (e->type <= EXPR_REG_END) {
nasm_error(ERR_NONFATAL,
"invalid effective address: too many registers");
return -1;
} else if (e->type < EXPR_SEGBASE) {
nasm_error(ERR_NONFATAL,
"invalid effective address: bad subexpression type");
return -1;
} else if (e->value == 1) {
if (op->segment != NO_SEG) {
nasm_error(ERR_NONFATAL,
"invalid effective address: multiple base segments");
return -1;
}
op->segment = e->type - EXPR_SEGBASE;
} else if (e->value == -1 &&
e->type == location.segment + EXPR_SEGBASE &&
!(op->opflags & OPFLAG_RELATIVE)) {
op->opflags |= OPFLAG_RELATIVE;
} else {
nasm_error(ERR_NONFATAL,
"invalid effective address: impossible segment base multiplier");
return -1;
}
}
}
}
}
nasm_assert(!e->type); /* We should be at the end */
op->basereg = b;
op->indexreg = i;
op->scale = s;
op->offset = o;
return 0;
}
static void mref_set_optype(operand *op)
{
int b = op->basereg;
int i = op->indexreg;
int s = op->scale;
/* It is memory, but it can match any r/m operand */
op->type |= MEMORY_ANY;
if (b == -1 && (i == -1 || s == 0)) {
int is_rel = globalbits == 64 &&
!(op->eaflags & EAF_ABS) &&
((globalrel &&
!(op->eaflags & EAF_FSGS)) ||
(op->eaflags & EAF_REL));
op->type |= is_rel ? IP_REL : MEM_OFFS;
}
if (i != -1) {
opflags_t iclass = nasm_reg_flags[i];
if (is_class(XMMREG,iclass))
op->type |= XMEM;
else if (is_class(YMMREG,iclass))
op->type |= YMEM;
else if (is_class(ZMMREG,iclass))
op->type |= ZMEM;
}
}
/*
* Convert an expression vector returned from evaluate() into an
* extop structure. Return zero on success.
*/
static int value_to_extop(expr * vect, extop *eop, int32_t myseg)
{
eop->type = EOT_DB_NUMBER;
eop->offset = 0;
eop->segment = eop->wrt = NO_SEG;
eop->relative = false;
for (; vect->type; vect++) {
if (!vect->value) /* zero term, safe to ignore */
continue;
if (vect->type <= EXPR_REG_END) /* false if a register is present */
return -1;
if (vect->type == EXPR_UNKNOWN) /* something we can't resolve yet */
return 0;
if (vect->type == EXPR_SIMPLE) {
/* Simple number expression */
eop->offset += vect->value;
continue;
}
if (eop->wrt == NO_SEG && !eop->relative && vect->type == EXPR_WRT) {
/* WRT term */
eop->wrt = vect->value;
continue;
}
if (!eop->relative &&
vect->type == EXPR_SEGBASE + myseg && vect->value == -1) {
/* Expression of the form: foo - $ */
eop->relative = true;
continue;
}
if (eop->segment == NO_SEG && vect->type >= EXPR_SEGBASE &&
vect->value == 1) {
eop->segment = vect->type - EXPR_SEGBASE;
continue;
}
/* Otherwise, badness */
return -1;
}
/* We got to the end and it was all okay */
return 0;
}
insn *parse_line(int pass, char *buffer, insn *result)
{
bool insn_is_label = false;
struct eval_hints hints;
int opnum;
int critical;
bool first;
bool recover;
int i;
nasm_static_assert(P_none == 0);
restart_parse:
first = true;
result->forw_ref = false;
stdscan_reset();
stdscan_set(buffer);
i = stdscan(NULL, &tokval);
memset(result->prefixes, P_none, sizeof(result->prefixes));
result->times = 1; /* No TIMES either yet */
result->label = NULL; /* Assume no label */
result->eops = NULL; /* must do this, whatever happens */
result->operands = 0; /* must initialize this */
result->evex_rm = 0; /* Ensure EVEX rounding mode is reset */
result->evex_brerop = -1; /* Reset EVEX broadcasting/ER op position */
/* Ignore blank lines */
if (i == TOKEN_EOS)
goto fail;
if (i != TOKEN_ID &&
i != TOKEN_INSN &&
i != TOKEN_PREFIX &&
(i != TOKEN_REG || !IS_SREG(tokval.t_integer))) {
nasm_error(ERR_NONFATAL,
"label or instruction expected at start of line");
goto fail;
}
if (i == TOKEN_ID || (insn_is_label && i == TOKEN_INSN)) {
/* there's a label here */
first = false;
result->label = tokval.t_charptr;
i = stdscan(NULL, &tokval);
if (i == ':') { /* skip over the optional colon */
i = stdscan(NULL, &tokval);
} else if (i == 0) {
nasm_error(ERR_WARNING | ERR_WARN_OL | ERR_PASS1,
"label alone on a line without a colon might be in error");
}
if (i != TOKEN_INSN || tokval.t_integer != I_EQU) {
/*
* FIXME: location.segment could be NO_SEG, in which case
* it is possible we should be passing 'absolute.segment'. Look into this.
* Work out whether that is *really* what we should be doing.
* Generally fix things. I think this is right as it is, but
* am still not certain.
*/
define_label(result->label,
in_absolute ? absolute.segment : location.segment,
location.offset, true);
}
}
/* Just a label here */
if (i == TOKEN_EOS)
goto fail;
while (i == TOKEN_PREFIX ||
(i == TOKEN_REG && IS_SREG(tokval.t_integer))) {
first = false;
/*
* Handle special case: the TIMES prefix.
*/
if (i == TOKEN_PREFIX && tokval.t_integer == P_TIMES) {
expr *value;
i = stdscan(NULL, &tokval);
value = evaluate(stdscan, NULL, &tokval, NULL, pass0, NULL);
i = tokval.t_type;
if (!value) /* Error in evaluator */
goto fail;
if (!is_simple(value)) {
nasm_error(ERR_NONFATAL,
"non-constant argument supplied to TIMES");
result->times = 1L;
} else {
result->times = value->value;
if (value->value < 0) {
nasm_error(ERR_NONFATAL|ERR_PASS2, "TIMES value %"PRId64" is negative", value->value);
result->times = 0;
}
}
} else {
int slot = prefix_slot(tokval.t_integer);
if (result->prefixes[slot]) {
if (result->prefixes[slot] == tokval.t_integer)
nasm_error(ERR_WARNING | ERR_PASS1,
"instruction has redundant prefixes");
else
nasm_error(ERR_NONFATAL,
"instruction has conflicting prefixes");
}
result->prefixes[slot] = tokval.t_integer;
i = stdscan(NULL, &tokval);
}
}
if (i != TOKEN_INSN) {
int j;
enum prefixes pfx;
for (j = 0; j < MAXPREFIX; j++) {
if ((pfx = result->prefixes[j]) != P_none)
break;
}
if (i == 0 && pfx != P_none) {
/*
* Instruction prefixes are present, but no actual
* instruction. This is allowed: at this point we
* invent a notional instruction of RESB 0.
*/
result->opcode = I_RESB;
result->operands = 1;
nasm_zero(result->oprs);
result->oprs[0].type = IMMEDIATE;
result->oprs[0].offset = 0L;
result->oprs[0].segment = result->oprs[0].wrt = NO_SEG;
return result;
} else {
nasm_error(ERR_NONFATAL, "parser: instruction expected");
goto fail;
}
}
result->opcode = tokval.t_integer;
result->condition = tokval.t_inttwo;
/*
* INCBIN cannot be satisfied with incorrectly
* evaluated operands, since the correct values _must_ be known
* on the first pass. Hence, even in pass one, we set the
* `critical' flag on calling evaluate(), so that it will bomb
* out on undefined symbols.
*/
if (result->opcode == I_INCBIN) {
critical = (pass0 < 2 ? 1 : 2);
} else
critical = (pass == 2 ? 2 : 0);
if (opcode_is_db(result->opcode) || result->opcode == I_INCBIN) {
extop *eop, **tail = &result->eops, **fixptr;
int oper_num = 0;
int32_t sign;
result->eops_float = false;
/*
* Begin to read the DB/DW/DD/DQ/DT/DO/DY/DZ/INCBIN operands.
*/
while (1) {
i = stdscan(NULL, &tokval);
if (i == TOKEN_EOS)
break;
else if (first && i == ':') {
insn_is_label = true;
goto restart_parse;
}
first = false;
fixptr = tail;
eop = *tail = nasm_malloc(sizeof(extop));
tail = &eop->next;
eop->next = NULL;
eop->type = EOT_NOTHING;
oper_num++;
sign = +1;
/*
* is_comma_next() here is to distinguish this from
* a string used as part of an expression...
*/
if (i == TOKEN_STR && is_comma_next()) {
eop->type = EOT_DB_STRING;
eop->stringval = tokval.t_charptr;
eop->stringlen = tokval.t_inttwo;
i = stdscan(NULL, &tokval); /* eat the comma */
} else if (i == TOKEN_STRFUNC) {
bool parens = false;
const char *funcname = tokval.t_charptr;
enum strfunc func = tokval.t_integer;
i = stdscan(NULL, &tokval);
if (i == '(') {
parens = true;
i = stdscan(NULL, &tokval);
}
if (i != TOKEN_STR) {
nasm_error(ERR_NONFATAL,
"%s must be followed by a string constant",
funcname);
eop->type = EOT_NOTHING;
} else {
eop->type = EOT_DB_STRING_FREE;
eop->stringlen =
string_transform(tokval.t_charptr, tokval.t_inttwo,
&eop->stringval, func);
if (eop->stringlen == (size_t)-1) {
nasm_error(ERR_NONFATAL, "invalid string for transform");
eop->type = EOT_NOTHING;
}
}
if (parens && i && i != ')') {
i = stdscan(NULL, &tokval);
if (i != ')') {
nasm_error(ERR_NONFATAL, "unterminated %s function",
funcname);
}
}
if (i && i != ',')
i = stdscan(NULL, &tokval);
} else if (i == '-' || i == '+') {
char *save = stdscan_get();
int token = i;
sign = (i == '-') ? -1 : 1;
i = stdscan(NULL, &tokval);
if (i != TOKEN_FLOAT) {
stdscan_set(save);
i = tokval.t_type = token;
goto is_expression;
} else {
goto is_float;
}
} else if (i == TOKEN_FLOAT) {
is_float:
eop->type = EOT_DB_STRING;
result->eops_float = true;
eop->stringlen = db_bytes(result->opcode);
if (eop->stringlen > 16) {
nasm_error(ERR_NONFATAL, "floating-point constant"
" encountered in DY or DZ instruction");
eop->stringlen = 0;
} else if (eop->stringlen < 1) {
nasm_error(ERR_NONFATAL, "floating-point constant"
" encountered in unknown instruction");
/*
* fix suggested by Pedro Gimeno... original line was:
* eop->type = EOT_NOTHING;
*/
eop->stringlen = 0;
}
eop = nasm_realloc(eop, sizeof(extop) + eop->stringlen);
tail = &eop->next;
*fixptr = eop;
eop->stringval = (char *)eop + sizeof(extop);
if (!eop->stringlen ||
!float_const(tokval.t_charptr, sign,
(uint8_t *)eop->stringval, eop->stringlen))
eop->type = EOT_NOTHING;
i = stdscan(NULL, &tokval); /* eat the comma */
} else {
/* anything else, assume it is an expression */
expr *value;
is_expression:
value = evaluate(stdscan, NULL, &tokval, NULL,
critical, NULL);
i = tokval.t_type;
if (!value) /* Error in evaluator */
goto fail;
if (value_to_extop(value, eop, location.segment)) {
nasm_error(ERR_NONFATAL,
"operand %d: expression is not simple or relocatable",
oper_num);
}
}
/*
* We're about to call stdscan(), which will eat the
* comma that we're currently sitting on between
* arguments. However, we'd better check first that it
* _is_ a comma.
*/
if (i == TOKEN_EOS) /* also could be EOL */
break;
if (i != ',') {
nasm_error(ERR_NONFATAL, "comma expected after operand %d",
oper_num);
goto fail;
}
}
if (result->opcode == I_INCBIN) {
/*
* Correct syntax for INCBIN is that there should be
* one string operand, followed by one or two numeric
* operands.
*/
if (!result->eops || result->eops->type != EOT_DB_STRING)
nasm_error(ERR_NONFATAL, "`incbin' expects a file name");
else if (result->eops->next &&
result->eops->next->type != EOT_DB_NUMBER)
nasm_error(ERR_NONFATAL, "`incbin': second parameter is"
" non-numeric");
else if (result->eops->next && result->eops->next->next &&
result->eops->next->next->type != EOT_DB_NUMBER)
nasm_error(ERR_NONFATAL, "`incbin': third parameter is"
" non-numeric");
else if (result->eops->next && result->eops->next->next &&
result->eops->next->next->next)
nasm_error(ERR_NONFATAL,
"`incbin': more than three parameters");
else
return result;
/*
* If we reach here, one of the above errors happened.
* Throw the instruction away.
*/
goto fail;
} else /* DB ... */ if (oper_num == 0)
nasm_error(ERR_WARNING | ERR_PASS1,
"no operand for data declaration");
else
result->operands = oper_num;
return result;
}
/*
* Now we begin to parse the operands. There may be up to four
* of these, separated by commas, and terminated by a zero token.
*/
for (opnum = 0; opnum < MAX_OPERANDS; opnum++) {
operand *op = &result->oprs[opnum];
expr *value; /* used most of the time */
bool mref; /* is this going to be a memory ref? */
bool bracket; /* is it a [] mref, or a & mref? */
bool mib; /* compound (mib) mref? */
int setsize = 0;
decoflags_t brace_flags = 0; /* flags for decorators in braces */
op->disp_size = 0; /* have to zero this whatever */
op->eaflags = 0; /* and this */
op->opflags = 0;
op->decoflags = 0;
i = stdscan(NULL, &tokval);
if (i == TOKEN_EOS)
break; /* end of operands: get out of here */
else if (first && i == ':') {
insn_is_label = true;
goto restart_parse;
}
first = false;
op->type = 0; /* so far, no override */
while (i == TOKEN_SPECIAL) { /* size specifiers */
switch (tokval.t_integer) {
case S_BYTE:
if (!setsize) /* we want to use only the first */
op->type |= BITS8;
setsize = 1;
break;
case S_WORD:
if (!setsize)
op->type |= BITS16;
setsize = 1;
break;
case S_DWORD:
case S_LONG:
if (!setsize)
op->type |= BITS32;
setsize = 1;
break;
case S_QWORD:
if (!setsize)
op->type |= BITS64;
setsize = 1;
break;
case S_TWORD:
if (!setsize)
op->type |= BITS80;
setsize = 1;
break;
case S_OWORD:
if (!setsize)
op->type |= BITS128;
setsize = 1;
break;
case S_YWORD:
if (!setsize)
op->type |= BITS256;
setsize = 1;
break;
case S_ZWORD:
if (!setsize)
op->type |= BITS512;
setsize = 1;
break;
case S_TO:
op->type |= TO;
break;
case S_STRICT:
op->type |= STRICT;
break;
case S_FAR:
op->type |= FAR;
break;
case S_NEAR:
op->type |= NEAR;
break;
case S_SHORT:
op->type |= SHORT;
break;
default:
nasm_error(ERR_NONFATAL, "invalid operand size specification");
}
i = stdscan(NULL, &tokval);
}
if (i == '[' || i == '&') { /* memory reference */
mref = true;
bracket = (i == '[');
i = stdscan(NULL, &tokval); /* then skip the colon */
while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
process_size_override(result, op);
i = stdscan(NULL, &tokval);
}
/* when a comma follows an opening bracket - [ , eax*4] */
if (i == ',') {
/* treat as if there is a zero displacement virtually */
tokval.t_type = TOKEN_NUM;
tokval.t_integer = 0;
stdscan_set(stdscan_get() - 1); /* rewind the comma */
}
} else { /* immediate operand, or register */
mref = false;
bracket = false; /* placate optimisers */
}
if ((op->type & FAR) && !mref &&
result->opcode != I_JMP && result->opcode != I_CALL) {
nasm_error(ERR_NONFATAL, "invalid use of FAR operand specifier");
}
value = evaluate(stdscan, NULL, &tokval,
&op->opflags, critical, &hints);
i = tokval.t_type;
if (op->opflags & OPFLAG_FORWARD) {
result->forw_ref = true;
}
if (!value) /* Error in evaluator */
goto fail;
if (i == ':' && mref) { /* it was seg:offset */
/*
* Process the segment override.
*/
if (value[1].type != 0 ||
value->value != 1 ||
!IS_SREG(value->type))
nasm_error(ERR_NONFATAL, "invalid segment override");
else if (result->prefixes[PPS_SEG])
nasm_error(ERR_NONFATAL,
"instruction has conflicting segment overrides");
else {
result->prefixes[PPS_SEG] = value->type;
if (IS_FSGS(value->type))
op->eaflags |= EAF_FSGS;
}
i = stdscan(NULL, &tokval); /* then skip the colon */
while (i == TOKEN_SPECIAL || i == TOKEN_PREFIX) {
process_size_override(result, op);
i = stdscan(NULL, &tokval);
}
value = evaluate(stdscan, NULL, &tokval,
&op->opflags, critical, &hints);
i = tokval.t_type;
if (op->opflags & OPFLAG_FORWARD) {
result->forw_ref = true;
}
/* and get the offset */
if (!value) /* Error in evaluator */
goto fail;
}
mib = false;
if (mref && bracket && i == ',') {
/* [seg:base+offset,index*scale] syntax (mib) */
operand o1, o2; /* Partial operands */
if (parse_mref(&o1, value))
goto fail;
i = stdscan(NULL, &tokval); /* Eat comma */
value = evaluate(stdscan, NULL, &tokval, &op->opflags,
critical, &hints);
i = tokval.t_type;
if (!value)
goto fail;
if (parse_mref(&o2, value))
goto fail;
if (o2.basereg != -1 && o2.indexreg == -1) {
o2.indexreg = o2.basereg;
o2.scale = 1;
o2.basereg = -1;
}
if (o1.indexreg != -1 || o2.basereg != -1 || o2.offset != 0 ||
o2.segment != NO_SEG || o2.wrt != NO_SEG) {
nasm_error(ERR_NONFATAL, "invalid mib expression");
goto fail;
}
op->basereg = o1.basereg;
op->indexreg = o2.indexreg;
op->scale = o2.scale;
op->offset = o1.offset;
op->segment = o1.segment;
op->wrt = o1.wrt;
if (op->basereg != -1) {
op->hintbase = op->basereg;
op->hinttype = EAH_MAKEBASE;
} else if (op->indexreg != -1) {
op->hintbase = op->indexreg;
op->hinttype = EAH_NOTBASE;
} else {
op->hintbase = -1;
op->hinttype = EAH_NOHINT;
}
mib = true;
}
recover = false;
if (mref && bracket) { /* find ] at the end */
if (i != ']') {
nasm_error(ERR_NONFATAL, "parser: expecting ]");
recover = true;
} else { /* we got the required ] */
i = stdscan(NULL, &tokval);
if (i == TOKEN_DECORATOR || i == TOKEN_OPMASK) {
/* parse opmask (and zeroing) after an operand */
recover = parse_braces(&brace_flags);
i = tokval.t_type;
}
if (i != 0 && i != ',') {
nasm_error(ERR_NONFATAL, "comma or end of line expected");
recover = true;
}
}
} else { /* immediate operand */
if (i != 0 && i != ',' && i != ':' &&
i != TOKEN_DECORATOR && i != TOKEN_OPMASK) {
nasm_error(ERR_NONFATAL, "comma, colon, decorator or end of "
"line expected after operand");
recover = true;
} else if (i == ':') {
op->type |= COLON;
} else if (i == TOKEN_DECORATOR || i == TOKEN_OPMASK) {
/* parse opmask (and zeroing) after an operand */
recover = parse_braces(&brace_flags);
}
}
if (recover) {
do { /* error recovery */
i = stdscan(NULL, &tokval);
} while (i != 0 && i != ',');
}
/*
* now convert the exprs returned from evaluate()
* into operand descriptions...
*/
op->decoflags |= brace_flags;
if (mref) { /* it's a memory reference */
/* A mib reference was fully parsed already */
if (!mib) {
if (parse_mref(op, value))
goto fail;
op->hintbase = hints.base;
op->hinttype = hints.type;
}
mref_set_optype(op);
} else { /* it's not a memory reference */
if (is_just_unknown(value)) { /* it's immediate but unknown */
op->type |= IMMEDIATE;
op->opflags |= OPFLAG_UNKNOWN;
op->offset = 0; /* don't care */
op->segment = NO_SEG; /* don't care again */
op->wrt = NO_SEG; /* still don't care */
if(optimizing.level >= 0 && !(op->type & STRICT)) {
/* Be optimistic */
op->type |=
UNITY | SBYTEWORD | SBYTEDWORD | UDWORD | SDWORD;
}
} else if (is_reloc(value)) { /* it's immediate */
uint64_t n = reloc_value(value);
op->type |= IMMEDIATE;
op->offset = n;
op->segment = reloc_seg(value);
op->wrt = reloc_wrt(value);
op->opflags |= is_self_relative(value) ? OPFLAG_RELATIVE : 0;
if (is_simple(value)) {
if (n == 1)
op->type |= UNITY;
if (optimizing.level >= 0 && !(op->type & STRICT)) {
if ((uint32_t) (n + 128) <= 255)
op->type |= SBYTEDWORD;
if ((uint16_t) (n + 128) <= 255)
op->type |= SBYTEWORD;
if (n <= UINT64_C(0xFFFFFFFF))
op->type |= UDWORD;
if (n + UINT64_C(0x80000000) <= UINT64_C(0xFFFFFFFF))
op->type |= SDWORD;
}
}
} else if (value->type == EXPR_RDSAE) {
/*
* it's not an operand but a rounding or SAE decorator.
* put the decorator information in the (opflag_t) type field
* of previous operand.
*/
opnum--; op--;
switch (value->value) {
case BRC_RN:
case BRC_RU:
case BRC_RD:
case BRC_RZ:
case BRC_SAE:
op->decoflags |= (value->value == BRC_SAE ? SAE : ER);
result->evex_rm = value->value;
break;
default:
nasm_error(ERR_NONFATAL, "invalid decorator");
break;
}
} else { /* it's a register */
opflags_t rs;
uint64_t regset_size = 0;
if (value->type >= EXPR_SIMPLE || value->value != 1) {
nasm_error(ERR_NONFATAL, "invalid operand type");
goto fail;
}
/*
* We do not allow any kind of expression, except for
* reg+value in which case it is a register set.
*/
for (i = 1; value[i].type; i++) {
if (!value[i].value)
continue;
switch (value[i].type) {
case EXPR_SIMPLE:
if (!regset_size) {
regset_size = value[i].value + 1;
break;
}
/* fallthrough */
default:
nasm_error(ERR_NONFATAL, "invalid operand type");
goto fail;
}
}
if ((regset_size & (regset_size - 1)) ||
regset_size >= (UINT64_C(1) << REGSET_BITS)) {
nasm_error(ERR_NONFATAL | ERR_PASS2,
"invalid register set size");
regset_size = 0;
}
/* clear overrides, except TO which applies to FPU regs */
if (op->type & ~TO) {
/*
* we want to produce a warning iff the specified size
* is different from the register size
*/
rs = op->type & SIZE_MASK;
} else {
rs = 0;
}
/*
* Make sure we're not out of nasm_reg_flags, still
* probably this should be fixed when we're defining
* the label.
*
* An easy trigger is
*
* e equ 0x80000000:0
* pshufw word e-0
*
*/
if (value->type < EXPR_REG_START ||
value->type > EXPR_REG_END) {
nasm_error(ERR_NONFATAL, "invalid operand type");
goto fail;
}
op->type &= TO;
op->type |= REGISTER;
op->type |= nasm_reg_flags[value->type];
op->type |= (regset_size >> 1) << REGSET_SHIFT;
op->decoflags |= brace_flags;
op->basereg = value->type;
if (rs && (op->type & SIZE_MASK) != rs)
nasm_error(ERR_WARNING | ERR_PASS1,
"register size specification ignored");
}
}
/* remember the position of operand having broadcasting/ER mode */
if (op->decoflags & (BRDCAST_MASK | ER | SAE))
result->evex_brerop = opnum;
}
result->operands = opnum; /* set operand count */
/* clear remaining operands */
while (opnum < MAX_OPERANDS)
result->oprs[opnum++].type = 0;
/*
* Transform RESW, RESD, RESQ, REST, RESO, RESY, RESZ into RESB.
*/
if (opcode_is_resb(result->opcode)) {
result->oprs[0].offset *= resb_bytes(result->opcode);
result->oprs[0].offset *= result->times;
result->times = 1;
result->opcode = I_RESB;
}
return result;
fail:
result->opcode = I_none;
return result;
}
static int is_comma_next(void)
{
struct tokenval tv;
char *p;
int i;
p = stdscan_get();
i = stdscan(NULL, &tv);
stdscan_set(p);
return (i == ',' || i == ';' || !i);
}
void cleanup_insn(insn * i)
{
extop *e;
while ((e = i->eops)) {
i->eops = e->next;
if (e->type == EOT_DB_STRING_FREE)
nasm_free(e->stringval);
nasm_free(e);
}
}
Reference in New Issue View Git Blame Copy Permalink