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nasm/parser.c
H. Peter Anvin fe501957c0 Portability fixes 
Concentrate compiler dependencies to compiler.h; make sure compiler.h
is included first in every .c file (since some prototypes may depend
on the presence of feature request macros.)

Actually use the conditional inclusion of various functions (totally
broken in previous releases.)
2007-10-02 21:53:51 -07:00

829 lines
31 KiB
C
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/* parser.c source line parser for the Netwide Assembler
*
* The Netwide Assembler is copyright (C) 1996 Simon Tatham and
* Julian Hall. All rights reserved. The software is
* redistributable under the licence given in the file "Licence"
* distributed in the NASM archive.
*
* initial version 27/iii/95 by Simon Tatham
*/
#include "compiler.h"
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <ctype.h>
#include <inttypes.h>
#include "nasm.h"
#include "insns.h"
#include "nasmlib.h"
#include "stdscan.h"
#include "parser.h"
#include "float.h"
extern int in_abs_seg; /* ABSOLUTE segment flag */
extern int32_t abs_seg; /* ABSOLUTE segment */
extern int32_t abs_offset; /* ABSOLUTE segment offset */
#include "regflags.c" /* List of register flags */
static int is_comma_next(void);
static int i;
static struct tokenval tokval;
static efunc error;
static struct ofmt *outfmt; /* Structure of addresses of output routines */
static loc_t *location; /* Pointer to current line's segment,offset */
void parser_global_info(struct ofmt *output, loc_t * locp)
{
outfmt = output;
location = locp;
}
insn *parse_line(int pass, char *buffer, insn * result,
efunc errfunc, evalfunc evaluate, ldfunc ldef)
{
int operand;
int critical;
struct eval_hints hints;
result->forw_ref = FALSE;
error = errfunc;
stdscan_reset();
stdscan_bufptr = buffer;
i = stdscan(NULL, &tokval);
result->label = NULL; /* Assume no label */
result->eops = NULL; /* must do this, whatever happens */
result->operands = 0; /* must initialize this */
if (i == 0) { /* blank line - ignore */
result->opcode = -1; /* and no instruction either */
return result;
}
if (i != TOKEN_ID && i != TOKEN_INSN && i != TOKEN_PREFIX &&
(i != TOKEN_REG || (REG_SREG & ~reg_flags[tokval.t_integer]))) {
error(ERR_NONFATAL, "label or instruction expected"
" at start of line");
result->opcode = -1;
return result;
}
if (i == TOKEN_ID) { /* there's a label here */
result->label = tokval.t_charptr;
i = stdscan(NULL, &tokval);
if (i == ':') { /* skip over the optional colon */
i = stdscan(NULL, &tokval);
} else if (i == 0) {
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 'abs_seg'. 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.
*/
ldef(result->label, in_abs_seg ? abs_seg : location->segment,
location->offset, NULL, TRUE, FALSE, outfmt, errfunc);
}
}
if (i == 0) {
result->opcode = -1; /* this line contains just a label */
return result;
}
result->nprefix = 0;
result->times = 1L;
while (i == TOKEN_PREFIX ||
(i == TOKEN_REG && !(REG_SREG & ~reg_flags[tokval.t_integer])))
{
/*
* 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, error, NULL);
i = tokval.t_type;
if (!value) { /* but, error in evaluator */
result->opcode = -1; /* unrecoverable parse error: */
return result; /* ignore this instruction */
}
if (!is_simple(value)) {
error(ERR_NONFATAL,
"non-constant argument supplied to TIMES");
result->times = 1L;
} else {
result->times = value->value;
if (value->value < 0) {
error(ERR_NONFATAL, "TIMES value %d is negative",
value->value);
result->times = 0;
}
}
} else {
if (result->nprefix == MAXPREFIX)
error(ERR_NONFATAL,
"instruction has more than %d prefixes", MAXPREFIX);
else
result->prefixes[result->nprefix++] = tokval.t_integer;
i = stdscan(NULL, &tokval);
}
}
if (i != TOKEN_INSN) {
if (result->nprefix > 0 && i == 0) {
/*
* 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;
result->oprs[0].type = IMMEDIATE;
result->oprs[0].offset = 0L;
result->oprs[0].segment = result->oprs[0].wrt = NO_SEG;
return result;
} else {
error(ERR_NONFATAL, "parser: instruction expected");
result->opcode = -1;
return result;
}
}
result->opcode = tokval.t_integer;
result->condition = tokval.t_inttwo;
/*
* RESB, RESW and RESD 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. Nasty, but there's nothing we can
* do about it.
*
* For the moment, EQU has the same difficulty, so we'll
* include that.
*/
if (result->opcode == I_RESB || result->opcode == I_RESW ||
result->opcode == I_RESD || result->opcode == I_RESQ ||
result->opcode == I_REST || result->opcode == I_RESO ||
result->opcode == I_EQU || result->opcode == I_INCBIN) {
critical = pass0;
} else
critical = (pass == 2 ? 2 : 0);
if (result->opcode == I_DB || result->opcode == I_DW ||
result->opcode == I_DD || result->opcode == I_DQ ||
result->opcode == I_DT || result->opcode == I_DO ||
result->opcode == I_INCBIN) {
extop *eop, **tail = &result->eops, **fixptr;
int oper_num = 0;
result->eops_float = FALSE;
/*
* Begin to read the DB/DW/DD/DQ/DT/DO/INCBIN operands.
*/
while (1) {
i = stdscan(NULL, &tokval);
if (i == 0)
break;
fixptr = tail;
eop = *tail = nasm_malloc(sizeof(extop));
tail = &eop->next;
eop->next = NULL;
eop->type = EOT_NOTHING;
oper_num++;
if (i == TOKEN_NUM && tokval.t_charptr && 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 */
continue;
}
if ((i == TOKEN_FLOAT && is_comma_next())
|| i == '-' || i == '+') {
int32_t sign = +1;
if (i == '+' || i == '-') {
char *save = stdscan_bufptr;
int token = i;
sign = (i == '-') ? -1 : 1;
i = stdscan(NULL, &tokval);
if (i != TOKEN_FLOAT || !is_comma_next()) {
stdscan_bufptr = save;
i = tokval.t_type = token;
}
}
if (i == TOKEN_FLOAT) {
eop->type = EOT_DB_STRING;
result->eops_float = TRUE;
switch (result->opcode) {
case I_DW:
eop->stringlen = 2;
break;
case I_DD:
eop->stringlen = 4;
break;
case I_DQ:
eop->stringlen = 8;
break;
case I_DT:
eop->stringlen = 10;
break;
case I_DO:
eop->stringlen = 16;
break;
default:
error(ERR_NONFATAL, "floating-point constant"
" encountered in `db' instruction");
/*
* fix suggested by Pedro Gimeno... original line
* was:
* eop->type = EOT_NOTHING;
*/
eop->stringlen = 0;
break;
}
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, error))
eop->type = EOT_NOTHING;
i = stdscan(NULL, &tokval); /* eat the comma */
continue;
}
}
/* anything else */
{
expr *value;
value = evaluate(stdscan, NULL, &tokval, NULL,
critical, error, NULL);
i = tokval.t_type;
if (!value) { /* error in evaluator */
result->opcode = -1; /* unrecoverable parse error: */
return result; /* ignore this instruction */
}
if (is_unknown(value)) {
eop->type = EOT_DB_NUMBER;
eop->offset = 0; /* doesn't matter what we put */
eop->segment = eop->wrt = NO_SEG; /* likewise */
} else if (is_reloc(value)) {
eop->type = EOT_DB_NUMBER;
eop->offset = reloc_value(value);
eop->segment = reloc_seg(value);
eop->wrt = reloc_wrt(value);
} else {
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 == 0) /* also could be EOL */
break;
if (i != ',') {
error(ERR_NONFATAL, "comma expected after operand %d",
oper_num);
result->opcode = -1; /* unrecoverable parse error: */
return result; /* ignore this instruction */
}
}
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)
error(ERR_NONFATAL, "`incbin' expects a file name");
else if (result->eops->next &&
result->eops->next->type != EOT_DB_NUMBER)
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)
error(ERR_NONFATAL, "`incbin': third parameter is",
" non-numeric");
else if (result->eops->next && result->eops->next->next &&
result->eops->next->next->next)
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.
*/
result->opcode = -1;
return result;
} else /* DB ... */ if (oper_num == 0)
error(ERR_WARNING | ERR_PASS1,
"no operand for data declaration");
else
result->operands = oper_num;
return result;
}
/* right. 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 (operand = 0; operand < MAX_OPERANDS; operand++) {
expr *value; /* used most of the time */
int mref; /* is this going to be a memory ref? */
int bracket; /* is it a [] mref, or a & mref? */
int setsize = 0;
result->oprs[operand].addr_size = 0; /* have to zero this whatever */
result->oprs[operand].eaflags = 0; /* and this */
result->oprs[operand].opflags = 0;
i = stdscan(NULL, &tokval);
if (i == 0)
break; /* end of operands: get out of here */
result->oprs[operand].type = 0; /* so far, no override */
while (i == TOKEN_SPECIAL) { /* size specifiers */
switch ((int)tokval.t_integer) {
case S_BYTE:
if (!setsize) /* we want to use only the first */
result->oprs[operand].type |= BITS8;
setsize = 1;
break;
case S_WORD:
if (!setsize)
result->oprs[operand].type |= BITS16;
setsize = 1;
break;
case S_DWORD:
case S_LONG:
if (!setsize)
result->oprs[operand].type |= BITS32;
setsize = 1;
break;
case S_QWORD:
if (!setsize)
result->oprs[operand].type |= BITS64;
setsize = 1;
break;
case S_TWORD:
if (!setsize)
result->oprs[operand].type |= BITS80;
setsize = 1;
break;
case S_OWORD:
if (!setsize)
result->oprs[operand].type |= BITS128;
setsize = 1;
break;
case S_TO:
result->oprs[operand].type |= TO;
break;
case S_STRICT:
result->oprs[operand].type |= STRICT;
break;
case S_FAR:
result->oprs[operand].type |= FAR;
break;
case S_NEAR:
result->oprs[operand].type |= NEAR;
break;
case S_SHORT:
result->oprs[operand].type |= SHORT;
break;
default:
error(ERR_NONFATAL, "invalid operand size specification");
}
i = stdscan(NULL, &tokval);
}
if (i == '[' || i == '&') { /* memory reference */
mref = TRUE;
bracket = (i == '[');
while ((i = stdscan(NULL, &tokval)) == TOKEN_SPECIAL) {
/* check for address directives */
if (tasm_compatible_mode) {
switch ((int)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:
result->oprs[operand].type |= BITS8;
break;
case S_WORD:
result->oprs[operand].type |= BITS16;
break;
case S_DWORD:
case S_LONG:
result->oprs[operand].type |= BITS32;
break;
case S_QWORD:
result->oprs[operand].type |= BITS64;
break;
case S_TWORD:
result->oprs[operand].type |= BITS80;
break;
case S_OWORD:
result->oprs[operand].type |= BITS128;
break;
default:
error(ERR_NONFATAL,
"invalid operand size specification");
}
} else {
/* Standard NASM compatible syntax */
switch ((int)tokval.t_integer) {
case S_NOSPLIT:
result->oprs[operand].eaflags |= EAF_TIMESTWO;
break;
case S_REL:
result->oprs[operand].eaflags |= EAF_REL;
break;
case S_ABS:
result->oprs[operand].eaflags |= EAF_ABS;
break;
case S_BYTE:
result->oprs[operand].eaflags |= EAF_BYTEOFFS;
break;
case S_WORD:
result->oprs[operand].addr_size = 16;
result->oprs[operand].eaflags |= EAF_WORDOFFS;
break;
case S_DWORD:
case S_LONG:
result->oprs[operand].addr_size = 32;
result->oprs[operand].eaflags |= EAF_WORDOFFS;
break;
case S_QWORD:
result->oprs[operand].addr_size = 64;
result->oprs[operand].eaflags |= EAF_WORDOFFS;
break;
default:
error(ERR_NONFATAL, "invalid size specification in"
" effective address");
}
}
}
} else { /* immediate operand, or register */
mref = FALSE;
bracket = FALSE; /* placate optimisers */
}
if ((result->oprs[operand].type & FAR) && !mref &&
result->opcode != I_JMP && result->opcode != I_CALL) {
error(ERR_NONFATAL, "invalid use of FAR operand specifier");
}
value = evaluate(stdscan, NULL, &tokval,
&result->oprs[operand].opflags,
critical, error, &hints);
i = tokval.t_type;
if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
result->forw_ref = TRUE;
}
if (!value) { /* error in evaluator */
result->opcode = -1; /* unrecoverable parse error: */
return result; /* ignore this instruction */
}
if (i == ':' && mref) { /* it was seg:offset */
/*
* Process the segment override.
*/
if (value[1].type != 0 || value->value != 1 ||
REG_SREG & ~reg_flags[value->type])
error(ERR_NONFATAL, "invalid segment override");
else if (result->nprefix == MAXPREFIX)
error(ERR_NONFATAL,
"instruction has more than %d prefixes", MAXPREFIX);
else {
result->prefixes[result->nprefix++] = value->type;
if (!(REG_FSGS & ~reg_flags[value->type]))
result->oprs[operand].eaflags |= EAF_FSGS;
}
i = stdscan(NULL, &tokval); /* then skip the colon */
if (i == TOKEN_SPECIAL) { /* another check for size override */
switch ((int)tokval.t_integer) {
case S_WORD:
result->oprs[operand].addr_size = 16;
break;
case S_DWORD:
case S_LONG:
result->oprs[operand].addr_size = 32;
break;
case S_QWORD:
result->oprs[operand].addr_size = 64;
break;
default:
error(ERR_NONFATAL, "invalid size specification in"
" effective address");
}
i = stdscan(NULL, &tokval);
}
value = evaluate(stdscan, NULL, &tokval,
&result->oprs[operand].opflags,
critical, error, &hints);
i = tokval.t_type;
if (result->oprs[operand].opflags & OPFLAG_FORWARD) {
result->forw_ref = TRUE;
}
/* and get the offset */
if (!value) { /* but, error in evaluator */
result->opcode = -1; /* unrecoverable parse error: */
return result; /* ignore this instruction */
}
}
if (mref && bracket) { /* find ] at the end */
if (i != ']') {
error(ERR_NONFATAL, "parser: expecting ]");
do { /* error recovery again */
i = stdscan(NULL, &tokval);
} while (i != 0 && i != ',');
} else /* we got the required ] */
i = stdscan(NULL, &tokval);
} else { /* immediate operand */
if (i != 0 && i != ',' && i != ':') {
error(ERR_NONFATAL, "comma or end of line expected");
do { /* error recovery */
i = stdscan(NULL, &tokval);
} while (i != 0 && i != ',');
} else if (i == ':') {
result->oprs[operand].type |= COLON;
}
}
/* now convert the exprs returned from evaluate() into operand
* descriptions... */
if (mref) { /* it's a memory reference */
expr *e = value;
int b, i, s; /* basereg, indexreg, scale */
int64_t o; /* offset */
b = i = -1, o = s = 0;
result->oprs[operand].hintbase = hints.base;
result->oprs[operand].hinttype = hints.type;
if (e->type && e->type <= EXPR_REG_END) { /* this bit's a register */
if (e->value == 1) /* in fact it can be basereg */
b = e->type;
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 */
if (b != -1) /* If the first was the base, ... */
i = e->type, s = e->value; /* second has to be indexreg */
else if (e->value != 1) { /* If both want to be index */
error(ERR_NONFATAL,
"beroset-p-592-invalid effective address");
result->opcode = -1;
return result;
} else
b = e->type;
e++;
}
if (e->type != 0) { /* is there an offset? */
if (e->type <= EXPR_REG_END) { /* in fact, is there an error? */
error(ERR_NONFATAL,
"beroset-p-603-invalid effective address");
result->opcode = -1;
return result;
} else {
if (e->type == EXPR_UNKNOWN) {
o = 0; /* doesn't matter what */
result->oprs[operand].wrt = NO_SEG; /* nor this */
result->oprs[operand].segment = NO_SEG; /* or this */
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) {
result->oprs[operand].wrt = e->value;
e++;
} else
result->oprs[operand].wrt = NO_SEG;
/*
* Look for a segment base type.
*/
if (e->type && e->type < EXPR_SEGBASE) {
error(ERR_NONFATAL,
"beroset-p-630-invalid effective address");
result->opcode = -1;
return result;
}
while (e->type && e->value == 0)
e++;
if (e->type && e->value != 1) {
error(ERR_NONFATAL,
"beroset-p-637-invalid effective address");
result->opcode = -1;
return result;
}
if (e->type) {
result->oprs[operand].segment =
e->type - EXPR_SEGBASE;
e++;
} else
result->oprs[operand].segment = NO_SEG;
while (e->type && e->value == 0)
e++;
if (e->type) {
error(ERR_NONFATAL,
"beroset-p-650-invalid effective address");
result->opcode = -1;
return result;
}
}
}
} else {
o = 0;
result->oprs[operand].wrt = NO_SEG;
result->oprs[operand].segment = NO_SEG;
}
if (e->type != 0) { /* there'd better be nothing left! */
error(ERR_NONFATAL,
"beroset-p-663-invalid effective address");
result->opcode = -1;
return result;
}
/* It is memory, but it can match any r/m operand */
result->oprs[operand].type |= MEMORY_ANY;
if (b == -1 && (i == -1 || s == 0)) {
int is_rel = globalbits == 64 &&
!(result->oprs[operand].eaflags & EAF_ABS) &&
((globalrel &&
!(result->oprs[operand].eaflags & EAF_FSGS)) ||
(result->oprs[operand].eaflags & EAF_REL));
result->oprs[operand].type |= is_rel ? IP_REL : MEM_OFFS;
}
result->oprs[operand].basereg = b;
result->oprs[operand].indexreg = i;
result->oprs[operand].scale = s;
result->oprs[operand].offset = o;
} else { /* it's not a memory reference */
if (is_just_unknown(value)) { /* it's immediate but unknown */
result->oprs[operand].type |= IMMEDIATE;
result->oprs[operand].offset = 0; /* don't care */
result->oprs[operand].segment = NO_SEG; /* don't care again */
result->oprs[operand].wrt = NO_SEG; /* still don't care */
} else if (is_reloc(value)) { /* it's immediate */
result->oprs[operand].type |= IMMEDIATE;
result->oprs[operand].offset = reloc_value(value);
result->oprs[operand].segment = reloc_seg(value);
result->oprs[operand].wrt = reloc_wrt(value);
if (is_simple(value)) {
if (reloc_value(value) == 1)
result->oprs[operand].type |= UNITY;
if (optimizing >= 0 &&
!(result->oprs[operand].type & STRICT)) {
if (reloc_value(value) >= -128 &&
reloc_value(value) <= 127)
result->oprs[operand].type |= SBYTE;
}
}
} else { /* it's a register */
if (value->type >= EXPR_SIMPLE || value->value != 1) {
error(ERR_NONFATAL, "invalid operand type");
result->opcode = -1;
return result;
}
/*
* check that its only 1 register, not an expression...
*/
for (i = 1; value[i].type; i++)
if (value[i].value) {
error(ERR_NONFATAL, "invalid operand type");
result->opcode = -1;
return result;
}
/* clear overrides, except TO which applies to FPU regs */
if (result->oprs[operand].type & ~TO) {
/*
* we want to produce a warning iff the specified size
* is different from the register size
*/
i = result->oprs[operand].type & SIZE_MASK;
} else
i = 0;
result->oprs[operand].type &= TO;
result->oprs[operand].type |= REGISTER;
result->oprs[operand].type |= reg_flags[value->type];
result->oprs[operand].basereg = value->type;
if (i && (result->oprs[operand].type & SIZE_MASK) != i)
error(ERR_WARNING | ERR_PASS1,
"register size specification ignored");
}
}
}
result->operands = operand; /* set operand count */
while (operand < 3) /* clear remaining operands */
result->oprs[operand++].type = 0;
/*
* Transform RESW, RESD, RESQ, REST, RESO into RESB.
*/
switch (result->opcode) {
case I_RESW:
result->opcode = I_RESB;
result->oprs[0].offset *= 2;
break;
case I_RESD:
result->opcode = I_RESB;
result->oprs[0].offset *= 4;
break;
case I_RESQ:
result->opcode = I_RESB;
result->oprs[0].offset *= 8;
break;
case I_REST:
result->opcode = I_RESB;
result->oprs[0].offset *= 10;
break;
case I_RESO:
result->opcode = I_RESB;
result->oprs[0].offset *= 16;
break;
default:
break;
}
return result;
}
static int is_comma_next(void)
{
char *p;
int i;
struct tokenval tv;
p = stdscan_bufptr;
i = stdscan(NULL, &tv);
stdscan_bufptr = p;
return (i == ',' || i == ';' || !i);
}
void cleanup_insn(insn * i)
{
extop *e;
while (i->eops) {
e = i->eops;
i->eops = i->eops->next;
nasm_free(e);
}
}
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