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Diffstat (limited to 'exprlib.c')
| -rw-r--r-- | exprlib.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/exprlib.c b/exprlib.c new file mode 100644 index 0000000..7eb3436 --- /dev/null +++ b/exprlib.c @@ -0,0 +1,186 @@ +/* ----------------------------------------------------------------------- * + * + * Copyright 1996-2009 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. + * + * ----------------------------------------------------------------------- */ + +/* + * exprlib.c + * + * Library routines to manipulate expression data types. + */ + +#include "nasm.h" + +/* + * Return true if the argument is a simple scalar. (Or a far- + * absolute, which counts.) + */ +int is_simple(expr * vect) +{ + while (vect->type && !vect->value) + vect++; + if (!vect->type) + return 1; + if (vect->type != EXPR_SIMPLE) + return 0; + do { + vect++; + } while (vect->type && !vect->value); + if (vect->type && vect->type < EXPR_SEGBASE + SEG_ABS) + return 0; + return 1; +} + +/* + * Return true if the argument is a simple scalar, _NOT_ a far- + * absolute. + */ +int is_really_simple(expr * vect) +{ + while (vect->type && !vect->value) + vect++; + if (!vect->type) + return 1; + if (vect->type != EXPR_SIMPLE) + return 0; + do { + vect++; + } while (vect->type && !vect->value); + if (vect->type) + return 0; + return 1; +} + +/* + * Return true if the argument is relocatable (i.e. a simple + * scalar, plus at most one segment-base, plus possibly a WRT). + */ +int is_reloc(expr * vect) +{ + while (vect->type && !vect->value) /* skip initial value-0 terms */ + vect++; + if (!vect->type) /* trivially return true if nothing */ + return 1; /* is present apart from value-0s */ + if (vect->type < EXPR_SIMPLE) /* false if a register is present */ + return 0; + if (vect->type == EXPR_SIMPLE) { /* skip over a pure number term... */ + do { + vect++; + } while (vect->type && !vect->value); + if (!vect->type) /* ...returning true if that's all */ + return 1; + } + if (vect->type == EXPR_WRT) { /* skip over a WRT term... */ + do { + vect++; + } while (vect->type && !vect->value); + if (!vect->type) /* ...returning true if that's all */ + return 1; + } + if (vect->value != 0 && vect->value != 1) + return 0; /* segment base multiplier non-unity */ + do { /* skip over _one_ seg-base term... */ + vect++; + } while (vect->type && !vect->value); + if (!vect->type) /* ...returning true if that's all */ + return 1; + return 0; /* And return false if there's more */ +} + +/* + * Return true if the argument contains an `unknown' part. + */ +int is_unknown(expr * vect) +{ + while (vect->type && vect->type < EXPR_UNKNOWN) + vect++; + return (vect->type == EXPR_UNKNOWN); +} + +/* + * Return true if the argument contains nothing but an `unknown' + * part. + */ +int is_just_unknown(expr * vect) +{ + while (vect->type && !vect->value) + vect++; + return (vect->type == EXPR_UNKNOWN); +} + +/* + * Return the scalar part of a relocatable vector. (Including + * simple scalar vectors - those qualify as relocatable.) + */ +int64_t reloc_value(expr * vect) +{ + while (vect->type && !vect->value) + vect++; + if (!vect->type) + return 0; + if (vect->type == EXPR_SIMPLE) + return vect->value; + else + return 0; +} + +/* + * Return the segment number of a relocatable vector, or NO_SEG for + * simple scalars. + */ +int32_t reloc_seg(expr * vect) +{ + while (vect->type && (vect->type == EXPR_WRT || !vect->value)) + vect++; + if (vect->type == EXPR_SIMPLE) { + do { + vect++; + } while (vect->type && (vect->type == EXPR_WRT || !vect->value)); + } + if (!vect->type) + return NO_SEG; + else + return vect->type - EXPR_SEGBASE; +} + +/* + * Return the WRT segment number of a relocatable vector, or NO_SEG + * if no WRT part is present. + */ +int32_t reloc_wrt(expr * vect) +{ + while (vect->type && vect->type < EXPR_WRT) + vect++; + if (vect->type == EXPR_WRT) { + return vect->value; + } else + return NO_SEG; +} |