/* expr.c -operands, expressions-
Copyright (C) 1987, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/*
* This is really a branch office of as-read.c. I split it out to clearly
* distinguish the world of expressions from the world of statements.
* (It also gives smaller files to re-compile.)
* Here, "operand"s are of expressions, not instructions.
*/
#include <ctype.h>
#include <string.h>
#include "as.h"
#include "obstack.h"
static void clean_up_expression PARAMS ((expressionS * expressionP));
extern const char EXP_CHARS[], FLT_CHARS[];
/*
* Build any floating-point literal here.
* Also build any bignum literal here.
*/
/* Seems atof_machine can backscan through generic_bignum and hit whatever
happens to be loaded before it in memory. And its way too complicated
for me to fix right. Thus a hack. JF: Just make generic_bignum bigger,
and never write into the early words, thus they'll always be zero.
I hate Dean's floating-point code. Bleh. */
LITTLENUM_TYPE generic_bignum[SIZE_OF_LARGE_NUMBER + 6];
FLONUM_TYPE generic_floating_point_number =
{
&generic_bignum[6], /* low (JF: Was 0) */
&generic_bignum[SIZE_OF_LARGE_NUMBER + 6 - 1], /* high JF: (added +6) */
0, /* leader */
0, /* exponent */
0 /* sign */
};
/* If nonzero, we've been asked to assemble nan, +inf or -inf */
int generic_floating_point_magic;
floating_constant (expressionP)
expressionS *expressionP;
{
/* input_line_pointer->*/
/* floating-point constant. */
int error_code;
error_code = atof_generic
(&input_line_pointer, ".", EXP_CHARS,
&generic_floating_point_number);
if (error_code)
{
if (error_code == ERROR_EXPONENT_OVERFLOW)
{
as_bad ("bad floating-point constant: exponent overflow, probably assembling junk");
}
else
{
as_bad ("bad floating-point constant: unknown error code=%d.", error_code);
}
}
expressionP->X_seg = big_section;
/* input_line_pointer->just after constant, */
/* which may point to whitespace. */
expressionP->X_add_number = -1;
}
integer_constant (radix, expressionP)
int radix;
expressionS *expressionP;
{
register char *digit_2; /*->2nd digit of number. */
char c;
register valueT number; /* offset or (absolute) value */
register short int digit; /* value of next digit in current radix */
register short int maxdig = 0;/* highest permitted digit value. */
register int too_many_digits = 0; /* if we see >= this number of */
register char *name; /* points to name of symbol */
register symbolS *symbolP; /* points to symbol */
int small; /* true if fits in 32 bits. */
extern const char hex_value[]; /* in hex_value.c */
/* may be bignum, or may fit in 32 bits. */
/*
* most numbers fit into 32 bits, and we want this case to be fast.
* so we pretend it will fit into 32 bits. if, after making up a 32
* bit number, we realise that we have scanned more digits than
* comfortably fit into 32 bits, we re-scan the digits coding
* them into a bignum. for decimal and octal numbers we are conservative: some
* numbers may be assumed bignums when in fact they do fit into 32 bits.
* numbers of any radix can have excess leading zeros: we strive
* to recognise this and cast them back into 32 bits.
* we must check that the bignum really is more than 32
* bits, and change it back to a 32-bit number if it fits.
* the number we are looking for is expected to be positive, but
* if it fits into 32 bits as an unsigned number, we let it be a 32-bit
* number. the cavalier approach is for speed in ordinary cases.
*/
switch (radix)
{
case 2:
maxdig = 2;
too_many_digits = 33;
break;
case 8:
maxdig = radix = 8;
too_many_digits = 11;
break;
case 16:
maxdig = radix = 16;
too_many_digits = 9;
break;
case 10:
maxdig = radix = 10;
too_many_digits = 11;
}
c = *input_line_pointer;
input_line_pointer++;
digit_2 = input_line_pointer;
for (number = 0; (digit = hex_value[c]) < maxdig; c = *input_line_pointer++)
{
number = number * radix + digit;
}
/* c contains character after number. */
/* input_line_pointer->char after c. */
small = input_line_pointer - digit_2 < too_many_digits;
if (!small)
{
/*
* we saw a lot of digits. manufacture a bignum the hard way.
*/
LITTLENUM_TYPE *leader; /*->high order littlenum of the bignum. */
LITTLENUM_TYPE *pointer; /*->littlenum we are frobbing now. */
long carry;
leader = generic_bignum;
generic_bignum[0] = 0;
generic_bignum[1] = 0;
/* we could just use digit_2, but lets be mnemonic. */
input_line_pointer = --digit_2; /*->1st digit. */
c = *input_line_pointer++;
for (; (carry = hex_value[c]) < maxdig; c = *input_line_pointer++)
{
for (pointer = generic_bignum;
pointer <= leader;
pointer++)
{
long work;
work = carry + radix * *pointer;
*pointer = work & LITTLENUM_MASK;
carry = work >> LITTLENUM_NUMBER_OF_BITS;
}
if (carry)
{
if (leader < generic_bignum + SIZE_OF_LARGE_NUMBER - 1)
{ /* room to grow a longer bignum. */
*++leader = carry;
}
}
}
/* again, c is char after number, */
/* input_line_pointer->after c. */
know (sizeof (int) * 8 == 32);
know (LITTLENUM_NUMBER_OF_BITS == 16);
/* hence the constant "2" in the next line. */
if (leader < generic_bignum + 2)
{ /* will fit into 32 bits. */
number =
((generic_bignum[1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS)
| (generic_bignum[0] & LITTLENUM_MASK);
small = 1;
}
else
{
number = leader - generic_bignum + 1; /* number of littlenums in the bignum. */
}
}
if (small)
{
/*
* here with number, in correct radix. c is the next char.
* note that unlike un*x, we allow "011f" "0x9f" to
* both mean the same as the (conventional) "9f". this is simply easier
* than checking for strict canonical form. syntax sux!
*/
switch (c)
{
#ifdef LOCAL_LABELS_FB
case 'b':
{
/*
* backward ref to local label.
* because it is backward, expect it to be defined.
*/
/* Construct a local label. */
name = fb_label_name ((int) number, 0);
/* seen before, or symbol is defined: ok */
symbolP = symbol_find (name);
if ((symbolP != NULL) && (S_IS_DEFINED (symbolP)))
{
/* local labels are never absolute. don't waste time
checking absoluteness. */
know (SEG_NORMAL (S_GET_SEGMENT (symbolP)));
expressionP->X_add_symbol = symbolP;
expressionP->X_seg = S_GET_SEGMENT (symbolP);
}
else
{ /* either not seen or not defined. */
as_bad ("backw. ref to unknown label \"%d:\", 0 assumed.", number);
expressionP->X_seg = absolute_section;
}
expressionP->X_add_number = 0;
break;
} /* case 'b' */
case 'f':
{
/*
* forward reference. expect symbol to be undefined or
* unknown. undefined: seen it before. unknown: never seen
* it before.
* construct a local label name, then an undefined symbol.
* don't create a xseg frag for it: caller may do that.
* just return it as never seen before.
*/
name = fb_label_name ((int) number, 1);
symbolP = symbol_find_or_make (name);
/* we have no need to check symbol properties. */
#ifndef many_segments
/* since "know" puts its arg into a "string", we
can't have newlines in the argument. */
know (S_GET_SEGMENT (symbolP) == undefined_section || S_GET_SEGMENT (symbolP) == text_section || S_GET_SEGMENT (symbolP) == data_section);
#endif
expressionP->X_add_symbol = symbolP;
expressionP->X_seg = undefined_section;
expressionP->X_subtract_symbol = NULL;
expressionP->X_add_number = 0;
break;
} /* case 'f' */
#endif /* LOCAL_LABELS_FB */
#ifdef LOCAL_LABELS_DOLLAR
case '$':
{
/* If the dollar label is *currently* defined, then this is just
another reference to it. If it is not *currently* defined,
then this is a fresh instantiation of that number, so create
it. */
if (dollar_label_defined (number))
{
name = dollar_label_name (number, 0);
symbolP = symbol_find (name);
know (symbolP != NULL);
}
else
{
name = dollar_label_name (number, 1);
symbolP = symbol_find_or_make (name);
}
expressionP->X_add_symbol = symbolP;
expressionP->X_add_number = 0;
expressionP->X_seg = S_GET_SEGMENT (symbolP);
break;
} /* case '$' */
#endif /* LOCAL_LABELS_DOLLAR */
default:
{
expressionP->X_add_number = number;
expressionP->X_seg = absolute_section;
input_line_pointer--; /* restore following character. */
break;
} /* really just a number */
} /* switch on char following the number */
}
else
{ /* not a small number */
expressionP->X_add_number = number;
expressionP->X_seg = big_section;
input_line_pointer--; /*->char following number. */
} /* if (small) */
} /* integer_constant() */
/*
* Summary of operand().
*
* in: Input_line_pointer points to 1st char of operand, which may
* be a space.
*
* out: A expressionS. X_seg determines how to understand the rest of the
* expressionS.
* The operand may have been empty: in this case X_seg == SEG_ABSENT.
* Input_line_pointer->(next non-blank) char after operand.
*
*/
static segT
operand (expressionP)
register expressionS *expressionP;
{
register char c;
register symbolS *symbolP; /* points to symbol */
register char *name; /* points to name of symbol */
/* invented for humans only, hope */
/* optimising compiler flushes it! */
register short int radix; /* 2, 8, 10 or 16, 0 when floating */
/* 0 means we saw start of a floating- */
/* point constant. */
/* digits, assume it is a bignum. */
SKIP_WHITESPACE (); /* leading whitespace is part of operand. */
c = *input_line_pointer++; /* input_line_pointer->past char in c. */
switch (c)
{
#ifdef MRI
case '%':
integer_constant (2, expressionP);
break;
case '@':
integer_constant (8, expressionP);
break;
case '$':
integer_constant (16, expressionP);
break;
#endif
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
input_line_pointer--;
integer_constant (10, expressionP);
break;
case '0':
/* non-decimal radix */
c = *input_line_pointer;
switch (c)
{
default:
if (c && strchr (FLT_CHARS, c))
{
input_line_pointer++;
floating_constant (expressionP);
}
else
{
/* The string was only zero */
expressionP->X_add_symbol = 0;
expressionP->X_add_number = 0;
expressionP->X_seg = absolute_section;
}
break;
case 'x':
case 'X':
input_line_pointer++;
integer_constant (16, expressionP);
break;
case 'b':
#ifdef LOCAL_LABELS_FB
if (!*input_line_pointer
|| (!strchr ("+-.0123456789", *input_line_pointer)
&& !strchr (EXP_CHARS, *input_line_pointer)))
{
input_line_pointer--;
integer_constant (10, expressionP);
break;
}
#endif
case 'B':
input_line_pointer++;
integer_constant (2, expressionP);
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
integer_constant (8, expressionP);
break;
case 'f':
#ifdef LOCAL_LABELS_FB
/* if it says '0f' and the line ends or it doesn't look like
a floating point #, its a local label ref. dtrt */
/* likewise for the b's. xoxorich. */
if (c == 'f'
&& (!*input_line_pointer ||
(!strchr ("+-.0123456789", *input_line_pointer) &&
!strchr (EXP_CHARS, *input_line_pointer))))
{
input_line_pointer -= 1;
integer_constant (10, expressionP);
break;
}
#endif
case 'd':
case 'D':
case 'F':
case 'r':
case 'e':
case 'E':
case 'g':
case 'G':
input_line_pointer++;
floating_constant (expressionP);
expressionP->X_add_number = -(isupper (c) ? tolower (c) : c);
break;
#ifdef LOCAL_LABELS_DOLLAR
case '$':
integer_constant (10, expressionP);
break;
#endif
}
break;
case '(':
/* didn't begin with digit & not a name */
{
(void) expression (expressionP);
/* Expression() will pass trailing whitespace */
if (*input_line_pointer++ != ')')
{
as_bad ("Missing ')' assumed");
input_line_pointer--;
}
/* here with input_line_pointer->char after "(...)" */
}
return expressionP->X_seg;
case '\'':
/* Warning: to conform to other people's assemblers NO ESCAPEMENT is
permitted for a single quote. The next character, parity errors and
all, is taken as the value of the operand. VERY KINKY. */
expressionP->X_add_number = *input_line_pointer++;
expressionP->X_seg = absolute_section;
break;
case '~':
case '-':
case '+':
{
/* unary operator: hope for SEG_ABSOLUTE */
segT opseg = operand (expressionP);
if (opseg == absolute_section)
{
/* input_line_pointer -> char after operand */
if (c == '-')
{
expressionP->X_add_number = -expressionP->X_add_number;
/* Notice: '-' may overflow: no warning is given. This is
compatible with other people's assemblers. Sigh. */
}
else
{
expressionP->X_add_number = ~expressionP->X_add_number;
}
}
else if (opseg == text_section
|| opseg == data_section
|| opseg == bss_section
|| opseg == pass1_section
|| opseg == undefined_section)
{
if (c == '-')
{
expressionP->X_subtract_symbol = expressionP->X_add_symbol;
expressionP->X_add_symbol = 0;
expressionP->X_seg = diff_section;
}
else
as_warn ("Unary operator %c ignored because bad operand follows",
c);
}
else
as_warn ("Unary operator %c ignored because bad operand follows", c);
}
break;
case '.':
if (!is_part_of_name (*input_line_pointer))
{
char *fake;
extern struct obstack frags;
/* JF: '.' is pseudo symbol with value of current location
in current segment. */
#ifdef DOT_LABEL_PREFIX
fake = ".L0\001";
#else
fake = "L0\001";
#endif
symbolP = symbol_new (fake,
now_seg,
(valueT) (obstack_next_free (&frags) - frag_now->fr_literal),
frag_now);
expressionP->X_add_number = 0;
expressionP->X_add_symbol = symbolP;
expressionP->X_seg = now_seg;
break;
}
else
{
goto isname;
}
case ',':
case '\n':
case '\0':
eol:
/* can't imagine any other kind of operand */
expressionP->X_seg = absent_section;
input_line_pointer--;
md_operand (expressionP);
break;
default:
if (is_end_of_line[c])
goto eol;
if (is_name_beginner (c)) /* here if did not begin with a digit */
{
/*
* Identifier begins here.
* This is kludged for speed, so code is repeated.
*/
isname:
name = --input_line_pointer;
c = get_symbol_end ();
symbolP = symbol_find_or_make (name);
/* If we have an absolute symbol or a reg, then we know its value
now. */
expressionP->X_seg = S_GET_SEGMENT (symbolP);
if (expressionP->X_seg == absolute_section
|| expressionP->X_seg == reg_section)
expressionP->X_add_number = S_GET_VALUE (symbolP);
else
{
expressionP->X_add_number = 0;
expressionP->X_add_symbol = symbolP;
}
*input_line_pointer = c;
expressionP->X_subtract_symbol = NULL;
}
else
{
as_bad ("Bad expression");
expressionP->X_add_number = 0;
expressionP->X_seg = absolute_section;
}
}
/*
* It is more 'efficient' to clean up the expressionS when they are created.
* Doing it here saves lines of code.
*/
clean_up_expression (expressionP);
SKIP_WHITESPACE (); /*->1st char after operand. */
know (*input_line_pointer != ' ');
return (expressionP->X_seg);
} /* operand() */
/* Internal. Simplify a struct expression for use by expr() */
/*
* In: address of a expressionS.
* The X_seg field of the expressionS may only take certain values.
* Now, we permit SEG_PASS1 to make code smaller & faster.
* Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT.
* Out: expressionS may have been modified:
* 'foo-foo' symbol references cancelled to 0,
* which changes X_seg from SEG_DIFFERENCE to SEG_ABSOLUTE;
* Unused fields zeroed to help expr().
*/
static void
clean_up_expression (expressionP)
register expressionS *expressionP;
{
segT s = expressionP->X_seg;
if (s == absent_section
|| s == pass1_section)
{
expressionP->X_add_symbol = NULL;
expressionP->X_subtract_symbol = NULL;
expressionP->X_add_number = 0;
}
else if (s == big_section
|| s == absolute_section)
{
expressionP->X_subtract_symbol = NULL;
expressionP->X_add_symbol = NULL;
}
else if (s == undefined_section)
expressionP->X_subtract_symbol = NULL;
else if (s == diff_section)
{
/*
* It does not hurt to 'cancel' NULL==NULL
* when comparing symbols for 'eq'ness.
* It is faster to re-cancel them to NULL
* than to check for this special case.
*/
if (expressionP->X_subtract_symbol == expressionP->X_add_symbol
|| (expressionP->X_subtract_symbol
&& expressionP->X_add_symbol
&& expressionP->X_subtract_symbol->sy_frag == expressionP->X_add_symbol->sy_frag
&& S_GET_VALUE (expressionP->X_subtract_symbol) == S_GET_VALUE (expressionP->X_add_symbol)))
{
expressionP->X_subtract_symbol = NULL;
expressionP->X_add_symbol = NULL;
expressionP->X_seg = absolute_section;
}
}
else if (s == reg_section)
{
expressionP->X_add_symbol = NULL;
expressionP->X_subtract_symbol = NULL;
}
else
{
if (SEG_NORMAL (expressionP->X_seg))
{
expressionP->X_subtract_symbol = NULL;
}
else
{
BAD_CASE (expressionP->X_seg);
}
}
}
/*
* expr_part ()
*
* Internal. Made a function because this code is used in 2 places.
* Generate error or correct X_?????_symbol of expressionS.
*/
/*
* symbol_1 += symbol_2 ... well ... sort of.
*/
static segT
expr_part (symbol_1_PP, symbol_2_P)
symbolS **symbol_1_PP;
symbolS *symbol_2_P;
{
segT return_value;
#ifndef MANY_SEGMENTS
assert ((*symbol_1_PP) == NULL \
|| (S_GET_SEGMENT (*symbol_1_PP) == text_section) \
|| (S_GET_SEGMENT (*symbol_1_PP) == data_section) \
|| (S_GET_SEGMENT (*symbol_1_PP) == bss_section) \
|| (!S_IS_DEFINED (*symbol_1_PP)));
assert (symbol_2_P == NULL \
|| (S_GET_SEGMENT (symbol_2_P) == text_section) \
|| (S_GET_SEGMENT (symbol_2_P) == data_section) \
|| (S_GET_SEGMENT (symbol_2_P) == bss_section) \
|| (!S_IS_DEFINED (symbol_2_P)));
#endif
if (*symbol_1_PP)
{
if (!S_IS_DEFINED (*symbol_1_PP))
{
if (symbol_2_P)
{
return_value = pass1_section;
*symbol_1_PP = NULL;
}
else
{
know (!S_IS_DEFINED (*symbol_1_PP));
return_value = undefined_section;
}
}
else
{
if (symbol_2_P)
{
if (!S_IS_DEFINED (symbol_2_P))
{
*symbol_1_PP = NULL;
return_value = pass1_section;
}
else
{
/* {seg1} - {seg2} */
as_bad ("Expression too complex, 2 symbolS forgotten: \"%s\" \"%s\"",
S_GET_NAME (*symbol_1_PP), S_GET_NAME (symbol_2_P));
*symbol_1_PP = NULL;
return_value = absolute_section;
}
}
else
{
return_value = S_GET_SEGMENT (*symbol_1_PP);
}
}
}
else
{ /* (* symbol_1_PP) == NULL */
if (symbol_2_P)
{
*symbol_1_PP = symbol_2_P;
return_value = S_GET_SEGMENT (symbol_2_P);
}
else
{
*symbol_1_PP = NULL;
return_value = absolute_section;
}
}
#ifndef MANY_SEGMENTS
assert (return_value == absolute_section \
|| return_value == text_section \
|| return_value == data_section \
|| return_value == bss_section \
|| return_value == undefined_section \
|| return_value == pass1_section);
#endif
know ((*symbol_1_PP) == NULL
|| (S_GET_SEGMENT (*symbol_1_PP) == return_value));
return (return_value);
}
/* Expression parser. */
/*
* We allow an empty expression, and just assume (absolute,0) silently.
* Unary operators and parenthetical expressions are treated as operands.
* As usual, Q==quantity==operand, O==operator, X==expression mnemonics.
*
* We used to do a aho/ullman shift-reduce parser, but the logic got so
* warped that I flushed it and wrote a recursive-descent parser instead.
* Now things are stable, would anybody like to write a fast parser?
* Most expressions are either register (which does not even reach here)
* or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common.
* So I guess it doesn't really matter how inefficient more complex expressions
* are parsed.
*
* After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK.
* Also, we have consumed any leading or trailing spaces (operand does that)
* and done all intervening operators.
*/
typedef enum
{
O_illegal, /* (0) what we get for illegal op */
O_multiply, /* (1) * */
O_divide, /* (2) / */
O_modulus, /* (3) % */
O_left_shift, /* (4) < */
O_right_shift, /* (5) > */
O_bit_inclusive_or, /* (6) | */
O_bit_or_not, /* (7) ! */
O_bit_exclusive_or, /* (8) ^ */
O_bit_and, /* (9) & */
O_add, /* (10) + */
O_subtract /* (11) - */
}
operatorT;
#define __ O_illegal
static const operatorT op_encoding[256] =
{ /* maps ASCII->operators */
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, O_bit_or_not, __, __, __, O_modulus, O_bit_and, __,
__, __, O_multiply, O_add, __, O_subtract, __, O_divide,
__, __, __, __, __, __, __, __,
__, __, __, __, O_left_shift, __, O_right_shift, __,
__, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __,
__, __, __, __, __, __, O_bit_exclusive_or, __,
__, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __,
__, __, __, __, O_bit_inclusive_or, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
__, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __
};
/*
* Rank Examples
* 0 operand, (expression)
* 1 + -
* 2 & ^ ! |
* 3 * / % << >>
*/
static const operator_rankT
op_rank[] =
{0, 3, 3, 3, 3, 3, 2, 2, 2, 2, 1, 1};
/* Return resultP->X_seg. */
segT
expr (rank, resultP)
register operator_rankT rank; /* Larger # is higher rank. */
register expressionS *resultP; /* Deliver result here. */
{
expressionS right;
register operatorT op_left;
register char c_left; /* 1st operator character. */
register operatorT op_right;
register char c_right;
know (rank >= 0);
(void) operand (resultP);
know (*input_line_pointer != ' '); /* Operand() gobbles spaces. */
c_left = *input_line_pointer; /* Potential operator character. */
op_left = op_encoding[c_left];
while (op_left != O_illegal && op_rank[(int) op_left] > rank)
{
input_line_pointer++; /*->after 1st character of operator. */
/* Operators "<<" and ">>" have 2 characters. */
if (*input_line_pointer == c_left && (c_left == '<' || c_left == '>'))
{
input_line_pointer++;
} /*->after operator. */
if (absent_section == expr (op_rank[(int) op_left], &right))
{
as_warn ("Missing operand value assumed absolute 0.");
resultP->X_add_number = 0;
resultP->X_subtract_symbol = NULL;
resultP->X_add_symbol = NULL;
resultP->X_seg = absolute_section;
}
know (*input_line_pointer != ' ');
c_right = *input_line_pointer;
op_right = op_encoding[c_right];
if (*input_line_pointer == c_right && (c_right == '<' || c_right == '>'))
{
input_line_pointer++;
} /*->after operator. */
know ((int) op_right == 0 || op_rank[(int) op_right] <= op_rank[(int) op_left]);
/* input_line_pointer->after right-hand quantity. */
/* left-hand quantity in resultP */
/* right-hand quantity in right. */
/* operator in op_left. */
if (resultP->X_seg == pass1_section || right.X_seg == pass1_section)
{
resultP->X_seg = pass1_section;
}
else
{
if (resultP->X_seg == big_section)
{
as_warn ("Left operand of %c is a %s. Integer 0 assumed.",
c_left, resultP->X_add_number > 0 ? "bignum" : "float");
resultP->X_seg = absolute_section;
resultP->X_add_symbol = 0;
resultP->X_subtract_symbol = 0;
resultP->X_add_number = 0;
}
if (right.X_seg == big_section)
{
as_warn ("Right operand of %c is a %s. Integer 0 assumed.",
c_left, right.X_add_number > 0 ? "bignum" : "float");
right.X_seg = absolute_section;
right.X_add_symbol = 0;
right.X_subtract_symbol = 0;
right.X_add_number = 0;
}
if (op_left == O_subtract)
{
/*
* Convert - into + by exchanging symbolS and negating number.
* I know -infinity can't be negated in 2's complement:
* but then it can't be subtracted either. This trick
* does not cause any further inaccuracy.
*/
register symbolS *symbolP;
right.X_add_number = -right.X_add_number;
symbolP = right.X_add_symbol;
right.X_add_symbol = right.X_subtract_symbol;
right.X_subtract_symbol = symbolP;
if (symbolP)
{
right.X_seg = diff_section;
}
op_left = O_add;
}
if (op_left == O_add)
{
segT seg1;
segT seg2;
#ifndef MANY_SEGMENTS
know (resultP->X_seg == data_section || resultP->X_seg == text_section || resultP->X_seg == bss_section || resultP->X_seg == undefined_section || resultP->X_seg == diff_section || resultP->X_seg == absolute_section || resultP->X_seg == pass1_section || resultP->X_seg == reg_section);
know (right.X_seg == data_section || right.X_seg == text_section || right.X_seg == bss_section || right.X_seg == undefined_section || right.X_seg == diff_section || right.X_seg == absolute_section || right.X_seg == pass1_section);
#endif
clean_up_expression (&right);
clean_up_expression (resultP);
seg1 = expr_part (&resultP->X_add_symbol, right.X_add_symbol);
seg2 = expr_part (&resultP->X_subtract_symbol, right.X_subtract_symbol);
if (seg1 == pass1_section || seg2 == pass1_section)
{
need_pass_2 = 1;
resultP->X_seg = pass1_section;
}
else if (seg2 == absolute_section)
resultP->X_seg = seg1;
else if (seg1 != undefined_section
&& seg1 != absolute_section
&& seg2 != undefined_section
&& seg1 != seg2)
{
know (seg2 != absolute_section);
know (resultP->X_subtract_symbol);
#ifndef MANY_SEGMENTS
know (seg1 == text_section || seg1 == data_section || seg1 == bss_section);
know (seg2 == text_section || seg2 == data_section || seg2 == bss_section);
#endif
know (resultP->X_add_symbol);
know (resultP->X_subtract_symbol);
as_bad ("Expression too complex: forgetting %s - %s",
S_GET_NAME (resultP->X_add_symbol),
S_GET_NAME (resultP->X_subtract_symbol));
resultP->X_seg = absolute_section;
/* Clean_up_expression() will do the rest. */
}
else
resultP->X_seg = diff_section;
resultP->X_add_number += right.X_add_number;
clean_up_expression (resultP);
}
else
{ /* Not +. */
if (resultP->X_seg == undefined_section || right.X_seg == undefined_section)
{
resultP->X_seg = pass1_section;
need_pass_2 = 1;
}
else
{
resultP->X_subtract_symbol = NULL;
resultP->X_add_symbol = NULL;
/* Will be absolute_section. */
if (resultP->X_seg != absolute_section || right.X_seg != absolute_section)
{
as_bad ("Relocation error. Absolute 0 assumed.");
resultP->X_seg = absolute_section;
resultP->X_add_number = 0;
}
else
{
switch (op_left)
{
case O_bit_inclusive_or:
resultP->X_add_number |= right.X_add_number;
break;
case O_modulus:
if (right.X_add_number)
{
resultP->X_add_number %= right.X_add_number;
}
else
{
as_warn ("Division by 0. 0 assumed.");
resultP->X_add_number = 0;
}
break;
case O_bit_and:
resultP->X_add_number &= right.X_add_number;
break;
case O_multiply:
resultP->X_add_number *= right.X_add_number;
break;
case O_divide:
if (right.X_add_number)
{
resultP->X_add_number /= right.X_add_number;
}
else
{
as_warn ("Division by 0. 0 assumed.");
resultP->X_add_number = 0;
}
break;
case O_left_shift:
resultP->X_add_number <<= right.X_add_number;
break;
case O_right_shift:
resultP->X_add_number >>= right.X_add_number;
break;
case O_bit_exclusive_or:
resultP->X_add_number ^= right.X_add_number;
break;
case O_bit_or_not:
resultP->X_add_number |= ~right.X_add_number;
break;
default:
BAD_CASE (op_left);
break;
} /* switch(operator) */
}
} /* If we have to force need_pass_2. */
} /* If operator was +. */
} /* If we didn't set need_pass_2. */
op_left = op_right;
} /* While next operator is >= this rank. */
return (resultP->X_seg);
}
/*
* get_symbol_end()
*
* This lives here because it belongs equally in expr.c & read.c.
* Expr.c is just a branch office read.c anyway, and putting it
* here lessens the crowd at read.c.
*
* Assume input_line_pointer is at start of symbol name.
* Advance input_line_pointer past symbol name.
* Turn that character into a '\0', returning its former value.
* This allows a string compare (RMS wants symbol names to be strings)
* of the symbol name.
* There will always be a char following symbol name, because all good
* lines end in end-of-line.
*/
char
get_symbol_end ()
{
register char c;
while (is_part_of_name (c = *input_line_pointer++))
;
*--input_line_pointer = 0;
return (c);
}
unsigned int
get_single_number ()
{
expressionS exp;
operand (&exp);
return exp.X_add_number;
}
/* end of expr.c */