chromium/third_party/nasm/asm/eval.c

/* ----------------------------------------------------------------------- *
 *
 *   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;
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 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ----------------------------------------------------------------------- */

/*
 * eval.c    expression evaluator for the Netwide Assembler
 */

#include "compiler.h"

#include "nctype.h"

#include "nasm.h"
#include "nasmlib.h"
#include "ilog2.h"
#include "error.h"
#include "eval.h"
#include "labels.h"
#include "floats.h"
#include "assemble.h"

#define TEMPEXPRS_DELTA …
#define TEMPEXPR_DELTA …

static scanner scanfunc;        /* Address of scanner routine */
static void *scpriv;            /* Scanner private pointer */

static expr **tempexprs = …;
static int ntempexprs;
static int tempexprs_size = …;

static expr *tempexpr;
static int ntempexpr;
static int tempexpr_size;

static struct tokenval *tokval; /* The current token */
static int tt;                   /* The t_type of tokval */

static bool critical;
static int *opflags;

static struct eval_hints *hint;
static int64_t deadman;


/*
 * Unimportant cleanup is done to avoid confusing people who are trying
 * to debug real memory leaks
 */
void eval_cleanup(void)
{ … }

/*
 * Construct a temporary expression.
 */
static void begintemp(void)
{ … }

static void addtotemp(int32_t type, int64_t value)
{ … }

static expr *finishtemp(void)
{ … }

/*
 * Add two vector datatypes. We have some bizarre behaviour on far-
 * absolute segment types: we preserve them during addition _only_
 * if one of the segments is a truly pure scalar.
 */
static expr *add_vectors(expr * p, expr * q)
{ … }

/*
 * Multiply a vector by a scalar. Strip far-absolute segment part
 * if present.
 *
 * Explicit treatment of UNKNOWN is not required in this routine,
 * since it will silently do the Right Thing anyway.
 *
 * If `affect_hints' is set, we also change the hint type to
 * NOTBASE if a MAKEBASE hint points at a register being
 * multiplied. This allows [eax*1+ebx] to hint EBX rather than EAX
 * as the base register.
 */
static expr *scalar_mult(expr * vect, int64_t scalar, int affect_hints)
{ … }

static expr *scalarvect(int64_t scalar)
{ … }

static expr *unknown_expr(void)
{ … }

/*
 * The SEG operator: calculate the segment part of a relocatable
 * value. Return NULL, as usual, if an error occurs. Report the
 * error too.
 */
static expr *segment_part(expr * e)
{ … }

/*
 * Recursive-descent parser. Called with a single boolean operand,
 * which is true if the evaluation is critical (i.e. unresolved
 * symbols are an error condition). Must update the global `tt' to
 * reflect the token after the parsed string. May return NULL.
 *
 * evaluate() should report its own errors: on return it is assumed
 * that if NULL has been returned, the error has already been
 * reported.
 *
 */

/*
 * Wrapper function around the scanner
 */
static int scan(void)
{ … }

/*
 * Grammar parsed is:
 *
 * expr  : bexpr [ WRT expr6 ]
 * bexpr : cexpr
 * cexpr : rexp0 [ {?} bexpr {:} cexpr ]
 * rexp0 : rexp1 [ {||} rexp1...]
 * rexp1 : rexp2 [ {^^} rexp2...]
 * rexp2 : rexp3 [ {&&} rexp3...]
 * rexp3 : expr0 [ {=,==,<>,!=,<,>,<=,>=,<=>} expr0... ]
 * expr0 : expr1 [ {|} expr1...]
 * expr1 : expr2 [ {^} expr2...]
 * expr2 : expr3 [ {&} expr3...]
 * expr3 : expr4 [ {<<,>>,<<<,>>>} expr4...]
 * expr4 : expr5 [ {+,-} expr5...]
 * expr5 : expr6 [ {*,/,%,//,%%} expr6...]
 * expr6 : { ~,+,-,IFUNC,SEG } expr6
 *       | (bexpr)
 *       | symbol
 *       | $
 *       | number
 */

static expr *cexpr(void);
static expr *rexp0(void), *rexp1(void), *rexp2(void), *rexp3(void);

static expr *expr0(void), *expr1(void), *expr2(void), *expr3(void);
static expr *expr4(void), *expr5(void), *expr6(void);

/* This inline is a placeholder for the root of the basic expression */
static inline expr *bexpr(void)
{ … }

static expr *cexpr(void)
{ … }

static expr *rexp0(void)
{ … }

static expr *rexp1(void)
{ … }

static expr *rexp2(void)
{ … }

static expr *rexp3(void)
{ … }

static expr *expr0(void)
{ … }

static expr *expr1(void)
{ … }

static expr *expr2(void)
{ … }

static expr *expr3(void)
{ … }

static expr *expr4(void)
{ … }

static expr *expr5(void)
{ … }

static expr *eval_floatize(enum floatize type)
{ … }

static expr *eval_strfunc(enum strfunc type, const char *name)
{ … }

static int64_t eval_ifunc(int64_t val, enum ifunc func)
{ … }

static expr *expr6(void)
{ … }

expr *evaluate(scanner sc, void *scprivate, struct tokenval *tv,
               int *fwref, bool crit, struct eval_hints *hints)
{ … }