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1d9da6043b
In far too many places, especially in directives, we don't accept an actual expression because, realistically, there have been way too many hoops to jump through to do so. Add helper functions to make that far easier. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
144 lines
4.1 KiB
C
144 lines
4.1 KiB
C
/* ----------------------------------------------------------------------- *
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*
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* Copyright 2018 The NASM Authors - All Rights Reserved
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* See the file AUTHORS included with the NASM distribution for
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* the specific copyright holders.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following
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* conditions are met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* ----------------------------------------------------------------------- */
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/*
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* Wrapper routine for evaluation
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*
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* Useful in directives etc. where we have a string and want a number
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* or possibly a relocatable expression.
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*/
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#include "compiler.h"
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#include "nasm.h"
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#include "stdscan.h"
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#include "eval.h"
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#include "evalstr.h"
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/*
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* Evaluate a simple value from a string. A segment and/or WRT MAY be
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* permitted, but if NULL is passed into the respective pointers, then
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* that is an error.
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*/
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static int stdscan_save(void *pvt, struct tokenval *tv)
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{
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char **strptr = pvt;
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*strptr = stdscan_get();
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return stdscan(NULL, tv);
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}
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int64_t evaluate_str(char **str, bool crit, int32_t *segment, int32_t *wrt)
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{
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struct tokenval tokval;
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expr *e;
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int32_t seg;
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stdscan_reset();
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stdscan_set(*str);
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tokval.t_type = TOKEN_INVALID;
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e = evaluate(stdscan_save, str, &tokval, NULL, crit, NULL);
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*str = nasm_skip_spaces(*str);
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if (segment)
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*segment = NO_SEG;
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if (is_unknown(e) && !crit)
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return 0;
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if (!is_reloc(e)) {
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nasm_nonfatal("invalid expression");
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return 0;
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}
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seg = reloc_seg(e);
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if (*segment) {
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*segment = seg;
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} else if (seg != NO_SEG) {
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nasm_nonfatal("expression cannot contain a segment reference");
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}
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seg = reloc_wrt(e);
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if (*wrt) {
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*wrt = seg;
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} else if (seg != NO_SEG) {
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nasm_nonfatal("expression cannot contain WRT");
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}
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return reloc_value(e);
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}
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/*
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* Evaluate a size expression: a pure integer, but size specifiers like
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* BYTE are treated like integer constants.
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*/
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static int stdscan_save_size(void *pvt, struct tokenval *tv)
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{
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char **strptr = pvt;
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int t;
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*strptr = stdscan_get();
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t = stdscan(NULL, tv);
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if (t == TOKEN_SIZE) {
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/* Treat size specifiers as integer constants */
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tv->t_type = t = TOKEN_NUM;
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tv->t_integer = tv->t_inttwo; /* Contains the size equivalent */
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}
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return t;
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}
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int64_t evaluate_size(char **str, bool crit)
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{
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struct tokenval tokval;
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expr *e;
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stdscan_reset();
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stdscan_set(*str);
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tokval.t_type = TOKEN_INVALID;
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e = evaluate(stdscan_save_size, str, &tokval, NULL, crit, NULL);
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*str = nasm_skip_spaces(*str);
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if (is_unknown(e) && !crit)
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return 0;
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if (!is_reloc(e) || reloc_seg(e) != NO_SEG || reloc_wrt(e) != NO_SEG) {
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nasm_nonfatal("invalid size expression");
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return 0;
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}
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return reloc_value(e);
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}
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