/* expr.c -operands, expressions-
Copyright (C) 1987 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 1, or (at your option)
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 "struc-symbol.h"
static void clean_up_expression(); /* Internal. */
extern const char EXP_CHARS
[]; /* JF hide MD floating pt stuff all the same place */
extern const char FLT_CHARS
[];
extern int local_label_defined
[];
* Build any floating-point literal here.
* Also build any bignum literal here.
/* LITTLENUM_TYPE generic_buffer [6]; /* JF this is a hack */
/* 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) */
/* If nonzero, we've been asked to assemble nan, +inf or -inf */
int generic_floating_point_magic
;
* in: Input_line_pointer points to 1st char of operand, which may
* out: A expressionS. X_seg determines how to understand the rest of the
* The operand may have been empty: in this case X_seg == SEG_NONE.
* Input_line_pointer -> (next non-blank) char after operand.
register expressionS
* expressionP
;
register char *name
; /* points to name of symbol */
register struct symbol
* symbolP
; /* Points to symbol */
extern char hex_value
[]; /* In hex_value.c */
char *local_label_name();
SKIP_WHITESPACE(); /* Leading whitespace is part of operand. */
c
= * input_line_pointer
++; /* Input_line_pointer -> past char in c. */
register valueT number
; /* offset or (absolute) value */
register short int digit
; /* value of next digit in current radix */
/* invented for humans only, hope */
/* optimising compiler flushes it! */
register short int radix
; /* 8, 10 or 16 */
/* 0 means we saw start of a floating- */
register short int maxdig
;/* Highest permitted digit value. */
register int too_many_digits
; /* If we see >= this number of */
/* digits, assume it is a bignum. */
register char * digit_2
; /* -> 2nd digit of number. */
int small
; /* TRUE if fits in 32 bits. */
{ /* non-decimal radix */
if ((c
= * input_line_pointer
++)=='x' || c
=='X')
c
= * input_line_pointer
++; /* read past "0x" or "0X" */
/* If it says '0f' and the line ends or it DOESN'T look like
a floating point #, its a local label ref. DTRT */
if(c
=='f' && (! *input_line_pointer
||
(!index("+-.0123456789",*input_line_pointer
) &&
!index(EXP_CHARS
,*input_line_pointer
))))
else if (c
&& index (FLT_CHARS
,c
))
radix
= 0; /* Start of floating-point constant. */
/* input_line_pointer -> 1st char of number. */
expressionP
-> X_add_number
= - (isupper(c
) ? tolower(c
) : c
);
{ /* By elimination, assume octal radix. */
maxdig
= 10; /* Un*x sux. Compatibility. */
/* c == char after "0" or "0x" or "0X" or "0e" etc.*/
{ /* Fixed-point integer constant. */
/* 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.
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
;
* 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. */
/* 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
;
work
= carry
+ radix
* * pointer
;
* pointer
= work
& LITTLENUM_MASK
;
carry
= work
>> LITTLENUM_NUMBER_OF_BITS
;
if (leader
< generic_bignum
+ SIZE_OF_LARGE_NUMBER
- 1)
{ /* Room to grow a longer bignum. */
/* Again, C is char after number, */
/* input_line_pointer -> after C. */
know( BITS_PER_INT
== 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. */
( (generic_bignum
[1] & LITTLENUM_MASK
) << LITTLENUM_NUMBER_OF_BITS
)
| (generic_bignum
[0] & LITTLENUM_MASK
);
number
= leader
- generic_bignum
+ 1; /* Number of littlenums in the bignum. */
* 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!
if (c
=='b' || (c
=='$' && local_label_defined
[number
]))
* Backward ref to local label.
* Because it is backward, expect it to be DEFINED.
* Construct a local label.
name
= local_label_name ((int)number
, 0);
if ( (symbolP
= symbol_table_lookup(name
)) /* seen before */
&& (symbolP
-> sy_type
& N_TYPE
) != N_UNDF
/* symbol is defined: OK */
{ /* Expected path: symbol defined. */
/* Local labels are never absolute. Don't waste time checking absoluteness. */
know( (symbolP
-> sy_type
& N_TYPE
) == N_DATA
|| (symbolP
-> sy_type
& N_TYPE
) == N_TEXT
);
expressionP
-> X_add_symbol
= symbolP
;
expressionP
-> X_add_number
= 0;
expressionP
-> X_seg
= N_TYPE_seg
[symbolP
-> sy_type
];
{ /* Either not seen or not defined. */
as_warn( "Backw. ref to unknown label \"%d:\", 0 assumed.",
expressionP
-> X_add_number
= 0;
expressionP
-> X_seg
= SEG_ABSOLUTE
;
if (c
=='f' || (c
=='$' && !local_label_defined
[number
]))
* Forward reference. Expect symbol to be undefined or
* unknown. Undefined: seen it before. Unknown: never seen
* 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
= local_label_name ((int)number
, 1);
if ( symbolP
= symbol_table_lookup( name
))
/* We have no need to check symbol properties. */
know( (symbolP
-> sy_type
& N_TYPE
) == N_UNDF
|| (symbolP
-> sy_type
& N_TYPE
) == N_DATA
|| (symbolP
-> sy_type
& N_TYPE
) == N_TEXT
);
symbolP
= symbol_new (name
, N_UNDF
, 0,0,0, & zero_address_frag
);
symbol_table_insert (symbolP
);
expressionP
-> X_add_symbol
= symbolP
;
expressionP
-> X_seg
= SEG_UNKNOWN
;
expressionP
-> X_subtract_symbol
= NULL
;
expressionP
-> X_add_number
= 0;
{ /* Really a number, not a local label. */
expressionP
-> X_add_number
= number
;
expressionP
-> X_seg
= SEG_ABSOLUTE
;
input_line_pointer
--; /* Restore following character. */
expressionP
-> X_add_number
= number
;
expressionP
-> X_seg
= SEG_ABSOLUTE
;
input_line_pointer
--; /* Restore following character. */
expressionP
-> X_add_number
= number
;
expressionP
-> X_seg
= SEG_BIG
;
input_line_pointer
--; /* -> char following number. */
} /* (If integer constant) */
{ /* input_line_pointer -> */
/* floating-point constant. */
error_code
= atof_generic
(& input_line_pointer
, ".", EXP_CHARS
,
& generic_floating_point_number
);
if (error_code
== ERROR_EXPONENT_OVERFLOW
)
as_warn( "Bad floating-point constant: exponent overflow, probably assembling junk" );
as_warn( "Bad floating-point constant: unknown error code=%d.", error_code
);
expressionP
-> X_seg
= SEG_BIG
;
/* input_line_pointer -> just after constant, */
/* which may point to whitespace. */
know( expressionP
-> X_add_number
< 0 ); /* < 0 means "floating point". */
} /* if (not floating-point constant) */
else if(c
=='.' && !is_part_of_name(*input_line_pointer
)) {
extern struct obstack frags
;
JF: '.' is pseudo symbol with value of current location in current
symbolP
= symbol_new("L0\001",
(unsigned char)(seg_N_TYPE
[(int)now_seg
]),
(valueT
)(obstack_next_free(&frags
)-frag_now
->fr_literal
),
expressionP
->X_add_number
=0;
expressionP
->X_add_symbol
=symbolP
;
expressionP
->X_seg
= now_seg
;
} else 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.
name
= -- input_line_pointer
;
symbolP
= symbol_table_lookup(name
);
* If we have an absolute symbol, then we know it's value now.
seg
= N_TYPE_seg
[(int) symbolP
-> sy_type
& N_TYPE
];
if ((expressionP
-> X_seg
= seg
) == SEG_ABSOLUTE
)
expressionP
-> X_add_number
= symbolP
-> sy_value
;
expressionP
-> X_add_number
= 0;
expressionP
-> X_add_symbol
= symbolP
;
expressionP
-> X_add_symbol
= symbol_new (name
, N_UNDF
, 0,0,0, & zero_address_frag
);
expressionP
-> X_add_number
= 0;
expressionP
-> X_seg
= SEG_UNKNOWN
;
symbol_table_insert (symbolP
);
* input_line_pointer
= c
;
expressionP
-> X_subtract_symbol
= NULL
;
else if (c
=='(')/* didn't begin with digit & not a name */
(void)expression( expressionP
);
/* Expression() will pass trailing whitespace */
if ( * input_line_pointer
++ != ')' )
as_warn( "Missing ')' assumed");
/* here with input_line_pointer -> char after "(...)" */
else if ( c
=='~' || c
=='-' )
{ /* unary operator: hope for SEG_ABSOLUTE */
switch(operand (expressionP
)) {
/* input_line_pointer -> char after operand */
expressionP
-> X_add_number
= - expressionP
-> X_add_number
;
* Notice: '-' may overflow: no warning is given. This is compatible
* with other people's assemblers. Sigh.
expressionP
-> X_add_number
= ~ expressionP
-> X_add_number
;
if(c
=='-') { /* JF I hope this hack works */
expressionP
->X_subtract_symbol
=expressionP
->X_add_symbol
;
expressionP
->X_add_symbol
=0;
expressionP
->X_seg
=SEG_DIFFERENCE
;
default: /* unary on non-absolute is unsuported */
as_warn("Unary operator %c ignored because bad operand follows", c
);
/* Expression undisturbed from operand(). */
* 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
= SEG_ABSOLUTE
;
/* can't imagine any other kind of operand */
expressionP
-> X_seg
= SEG_NONE
;
* 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
);
/* 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_NONE.
* 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().
clean_up_expression (expressionP
)
register expressionS
* expressionP
;
switch (expressionP
-> X_seg
)
expressionP
-> X_add_symbol
= NULL
;
expressionP
-> X_subtract_symbol
= NULL
;
expressionP
-> X_add_number
= 0;
expressionP
-> X_subtract_symbol
= NULL
;
expressionP
-> X_add_symbol
= NULL
;
expressionP
-> X_subtract_symbol
= NULL
;
* 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
&& expressionP
->X_subtract_symbol
->sy_value
==expressionP
->X_add_symbol
->sy_value
))
expressionP
-> X_subtract_symbol
= NULL
;
expressionP
-> X_add_symbol
= NULL
;
expressionP
-> X_seg
= SEG_ABSOLUTE
;
BAD_CASE( expressionP
-> X_seg
);
* 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.
expr_part (symbol_1_PP
, symbol_2_P
)
struct symbol
** symbol_1_PP
;
struct symbol
* symbol_2_P
;
know( (* symbol_1_PP
) == NULL
|| ((* symbol_1_PP
) -> sy_type
& N_TYPE
) == N_TEXT
|| ((* symbol_1_PP
) -> sy_type
& N_TYPE
) == N_DATA
|| ((* symbol_1_PP
) -> sy_type
& N_TYPE
) == N_BSS
|| ((* symbol_1_PP
) -> sy_type
& N_TYPE
) == N_UNDF
|| (symbol_2_P
-> sy_type
& N_TYPE
) == N_TEXT
|| (symbol_2_P
-> sy_type
& N_TYPE
) == N_DATA
|| (symbol_2_P
-> sy_type
& N_TYPE
) == N_BSS
|| (symbol_2_P
-> sy_type
& N_TYPE
) == N_UNDF
if (((* symbol_1_PP
) -> sy_type
& N_TYPE
) == N_UNDF
)
return_value
= SEG_PASS1
;
know( ((* symbol_1_PP
) -> sy_type
& N_TYPE
) == N_UNDF
)
return_value
= SEG_UNKNOWN
;
if ((symbol_2_P
-> sy_type
& N_TYPE
) == N_UNDF
)
return_value
= SEG_PASS1
;
as_warn( "Expression too complex, 2 symbols forgotten: \"%s\" \"%s\"",
(* symbol_1_PP
) -> sy_name
, symbol_2_P
-> sy_name
);
return_value
= SEG_ABSOLUTE
;
return_value
= N_TYPE_seg
[(* symbol_1_PP
) -> sy_type
& N_TYPE
];
{ /* (* symbol_1_PP) == NULL */
* symbol_1_PP
= symbol_2_P
;
return_value
= N_TYPE_seg
[(symbol_2_P
) -> sy_type
& N_TYPE
];
return_value
= SEG_ABSOLUTE
;
know( return_value
== SEG_ABSOLUTE
|| return_value
== SEG_TEXT
|| return_value
== SEG_DATA
|| return_value
== SEG_BSS
|| return_value
== SEG_UNKNOWN
|| return_value
== SEG_PASS1
know( (* symbol_1_PP
) == NULL
|| ((* symbol_1_PP
) -> sy_type
& N_TYPE
) == seg_N_TYPE
[(int) return_value
] );
* 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
* 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.
O_illegal
, /* (0) what we get for illegal op */
O_left_shift
, /* (4) < */
O_right_shift
, /* (5) > */
O_bit_inclusive_or
, /* (6) | */
O_bit_or_not
, /* (7) ! */
O_bit_exclusive_or
, /* (8) ^ */
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
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
,
__
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
, __
* 0 operand, (expression)
typedef char operator_rankT
;
static const operator_rankT
op_rank
[] = { 0, 3, 3, 3, 3, 3, 2, 2, 2, 2, 1, 1 };
segT
/* Return resultP -> X_seg. */
register operator_rankT rank
; /* Larger # is higher rank. */
register expressionS
* resultP
; /* Deliver result here. */
register operatorT op_left
;
register char c_left
; /* 1st operator character. */
register operatorT op_right
;
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
== '>') )
} /* -> after operator. */
if (SEG_NONE
== 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
= SEG_ABSOLUTE
;
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
== '>') )
} /* -> 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
== SEG_PASS1
|| right
. X_seg
== SEG_PASS1
)
resultP
-> X_seg
= SEG_PASS1
;
if ( resultP
-> X_seg
== SEG_BIG
)
as_warn( "Left operand of %c is a %s. Integer 0 assumed.",
c_left
, resultP
-> X_add_number
> 0 ? "bignum" : "float");
resultP
-> X_seg
= SEG_ABSOLUTE
;
resultP
-> X_add_symbol
= 0;
resultP
-> X_subtract_symbol
= 0;
resultP
-> X_add_number
= 0;
if ( right
. X_seg
== SEG_BIG
)
as_warn( "Right operand of %c is a %s. Integer 0 assumed.",
c_left
, right
. X_add_number
> 0 ? "bignum" : "float");
right
. X_seg
= SEG_ABSOLUTE
;
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 struct symbol
* 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
;
right
. X_seg
= SEG_DIFFERENCE
;
know( resultP
-> X_seg
== SEG_DATA
|| resultP
-> X_seg
== SEG_TEXT
|| resultP
-> X_seg
== SEG_BSS
|| resultP
-> X_seg
== SEG_UNKNOWN
|| resultP
-> X_seg
== SEG_DIFFERENCE
|| resultP
-> X_seg
== SEG_ABSOLUTE
|| resultP
-> X_seg
== SEG_PASS1
know( right
. X_seg
== SEG_DATA
|| right
. X_seg
== SEG_TEXT
|| right
. X_seg
== SEG_BSS
|| right
. X_seg
== SEG_UNKNOWN
|| right
. X_seg
== SEG_DIFFERENCE
|| right
. X_seg
== SEG_ABSOLUTE
|| right
. X_seg
== SEG_PASS1
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
== SEG_PASS1
|| seg2
== SEG_PASS1
) {
resultP
-> X_seg
= SEG_PASS1
;
} else if (seg2
== SEG_ABSOLUTE
)
else if ( seg1
!= SEG_UNKNOWN
know( seg2
!= SEG_ABSOLUTE
);
know( resultP
-> X_subtract_symbol
);
know( seg1
== SEG_TEXT
|| seg1
== SEG_DATA
|| seg1
== SEG_BSS
);
know( seg2
== SEG_TEXT
|| seg2
== SEG_DATA
|| seg2
== SEG_BSS
);
know( resultP
-> X_add_symbol
);
know( resultP
-> X_subtract_symbol
);
as_warn("Expression too complex: forgetting %s - %s",
resultP
-> X_add_symbol
-> sy_name
,
resultP
-> X_subtract_symbol
-> sy_name
);
resultP
-> X_seg
= SEG_ABSOLUTE
;
/* Clean_up_expression() will do the rest. */
resultP
-> X_seg
= SEG_DIFFERENCE
;
resultP
-> X_add_number
+= right
. X_add_number
;
clean_up_expression (resultP
);
if ( resultP
-> X_seg
== SEG_UNKNOWN
|| right
. X_seg
== SEG_UNKNOWN
)
resultP
-> X_seg
= SEG_PASS1
;
resultP
-> X_subtract_symbol
= NULL
;
resultP
-> X_add_symbol
= NULL
;
/* Will be SEG_ABSOLUTE. */
if ( resultP
-> X_seg
!= SEG_ABSOLUTE
|| right
. X_seg
!= SEG_ABSOLUTE
)
as_warn( "Relocation error. Absolute 0 assumed.");
resultP
-> X_seg
= SEG_ABSOLUTE
;
resultP
-> X_add_number
= 0;
resultP
-> X_add_number
|= right
. X_add_number
;
if (right
. X_add_number
)
resultP
-> X_add_number
%= right
. X_add_number
;
as_warn( "Division by 0. 0 assumed." );
resultP
-> X_add_number
= 0;
resultP
-> X_add_number
&= right
. X_add_number
;
resultP
-> X_add_number
*= right
. X_add_number
;
if (right
. X_add_number
)
resultP
-> X_add_number
/= right
. X_add_number
;
as_warn( "Division by 0. 0 assumed." );
resultP
-> X_add_number
= 0;
resultP
-> X_add_number
<<= right
. X_add_number
;
resultP
-> X_add_number
>>= right
. X_add_number
;
resultP
-> X_add_number
^= right
. X_add_number
;
resultP
-> X_add_number
|= ~ right
. X_add_number
;
} /* If we have to force need_pass_2. */
} /* If operator was +. */
} /* If we didn't set need_pass_2. */
} /* While next operator is >= this rank. */
return (resultP
-> X_seg
);
* 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)
* There will always be a char following symbol name, because all good
* lines end in end-of-line.
while ( is_part_of_name( c
= * input_line_pointer
++ ) )
* -- input_line_pointer
= 0;