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Diffstat (limited to 'gnu/usr.bin/gas/expr.c')
| -rw-r--r-- | gnu/usr.bin/gas/expr.c | 1007 |
1 files changed, 0 insertions, 1007 deletions
diff --git a/gnu/usr.bin/gas/expr.c b/gnu/usr.bin/gas/expr.c deleted file mode 100644 index 01d501192a5..00000000000 --- a/gnu/usr.bin/gas/expr.c +++ /dev/null @@ -1,1007 +0,0 @@ -/* $OpenBSD: expr.c,v 1.7 2000/07/26 15:42:57 deraadt Exp $ */ - -/* expr.c -operands, expressions- - Copyright (C) 1987, 1990, 1991, 1992 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. - */ - -#ifndef lint -static char rcsid[] = "$OpenBSD: expr.c,v 1.7 2000/07/26 15:42:57 deraadt Exp $"; -#endif - -#include <ctype.h> -#include <string.h> - -#include "as.h" - -#include "obstack.h" - -#if __STDC__ == 1 -static void clean_up_expression(expressionS *expressionP); -#else /* __STDC__ */ -static void clean_up_expression(); /* Internal. */ -#endif /* not __STDC__ */ -extern const char EXP_CHARS[]; /* JF hide MD floating pt stuff all the same place */ -extern const char FLT_CHARS[]; - -#ifdef LOCAL_LABELS_DOLLAR -extern int local_label_defined[]; -#endif - -/* - * 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) */ - 0, /* leader */ - 0, /* exponent */ - 0 /* sign */ - }; -/* If nonzero, we've been asked to assemble nan, +inf or -inf */ -int generic_floating_point_magic; - -/* - * 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 char *name; /* points to name of symbol */ - register symbolS * symbolP; /* Points to symbol */ - - extern const char hex_value[]; /* In hex_value.c */ - -#ifdef PIC -/* XXX */ expressionP->X_got_symbol = 0; -#endif - SKIP_WHITESPACE(); /* Leading whitespace is part of operand. */ - c = * input_line_pointer ++; /* Input_line_pointer->past char in c. */ - if (isdigit(c) || (c == 'H' && input_line_pointer[0] == '\'')) - { - 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; /* 2, 8, 10 or 16 */ - /* 0 means we saw start of a floating- */ - /* point constant. */ - register short int maxdig = 0;/* Highest permitted digit value. */ - register int too_many_digits = 0; /* 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. */ - - - if (c == 'H' || c == '0') { /* non-decimal radix */ - if ((c = *input_line_pointer ++) == 'x' || c == 'X' || c == '\'') { - c = *input_line_pointer ++; /* read past "0x" or "0X" or H' */ - maxdig = radix = 16; - too_many_digits = 9; - } else { - /* 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' || c == 'b' || c == 'B') - && (!*input_line_pointer || - (!strchr("+-.0123456789iInN",*input_line_pointer) && - !strchr(EXP_CHARS,*input_line_pointer)))) { - maxdig = radix = 10; - too_many_digits = 11; - c = '0'; - input_line_pointer -= 2; - - } else if (c == 'b' || c == 'B') { - c = *input_line_pointer++; - maxdig = radix = 2; - too_many_digits = 33; - - } else if (c && strchr(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); - - } else { /* By elimination, assume octal radix. */ - radix = maxdig = 8; - too_many_digits = 11; - } - } /* c == char after "0" or "0x" or "0X" or "0e" etc. */ - } else { - maxdig = radix = 10; - too_many_digits = 11; - } /* if operand starts with a zero */ - - if (radix) { /* 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; - 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! - */ - if (number<10) - { - if (0 -#ifdef LOCAL_LABELS_FB - || c == 'b' -#endif -#ifdef LOCAL_LABELS_DOLLAR - || (c == '$' && local_label_defined[number]) -#endif - ) - { - /* - * 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_find(name)) != NULL) /* seen before */ - && (S_IS_DEFINED(symbolP))) /* symbol is defined: OK */ - { /* Expected path: symbol defined. */ - /* 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_add_number = 0; - 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_add_number = 0; - expressionP->X_seg = SEG_ABSOLUTE; - } - } - else - { - if (0 -#ifdef LOCAL_LABELS_FB - || c == 'f' -#endif -#ifdef LOCAL_LABELS_DOLLAR - || (c == '$' && !local_label_defined[number]) -#endif - ) - { - /* - * Forward reference. Expect symbol to be undefined or - * unknown. Undefined: seen it before. Unknown: never seen - * it in this pass. - * 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); - 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) == SEG_UNKNOWN || S_GET_SEGMENT(symbolP) == SEG_TEXT || S_GET_SEGMENT(symbolP) == SEG_DATA); -#endif - expressionP->X_add_symbol = symbolP; - expressionP->X_seg = SEG_UNKNOWN; - expressionP->X_subtract_symbol = NULL; - expressionP->X_add_number = 0; - } - else - { /* Really a number, not a local label. */ - expressionP->X_add_number = number; - expressionP->X_seg = SEG_ABSOLUTE; - input_line_pointer--; /* Restore following character. */ - } /* if (c == 'f') */ - } /* if (c == 'b') */ - } - else - { /* Really a number. */ - expressionP->X_add_number = number; - expressionP->X_seg = SEG_ABSOLUTE; - input_line_pointer--; /* Restore following character. */ - } /* if (number<10) */ - } - else - { - expressionP->X_add_number = number; - expressionP->X_seg = SEG_BIG; - input_line_pointer --; /*->char following number. */ - } /* if (small) */ - } /* (If integer constant) */ - else - { /* 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 = 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 - segment... - */ - symbolP = symbol_new("\001L0", - 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; - - } 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 - 1; - 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); - switch (expressionP->X_seg) - { - case SEG_ABSOLUTE: - case SEG_REGISTER: - expressionP->X_add_number = S_GET_VALUE(symbolP); - break; - - default: - expressionP->X_add_number = 0; -#ifdef PIC - if (symbolP == GOT_symbol) { - expressionP->X_got_symbol = symbolP; - got_referenced = 1; - } else -#endif - expressionP->X_add_symbol = symbolP; - } - *input_line_pointer = c; - expressionP->X_subtract_symbol = NULL; - } else if (c == '(' || c == '[') {/* didn't begin with digit & not a name */ - (void)expression(expressionP); - /* Expression() will pass trailing whitespace */ - if (c == '(' && *input_line_pointer++ != ')' || - c == '[' && *input_line_pointer++ != ']') { - as_bad("Missing ')' assumed"); - input_line_pointer--; - } - /* here with input_line_pointer->char after "(...)" */ - } else if (c == '~' || c == '-' || c == '+') { - /* unary operator: hope for SEG_ABSOLUTE */ - switch (operand (expressionP)) { - case SEG_ABSOLUTE: - /* 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 if (c == '~') { - expressionP->X_add_number = ~ expressionP->X_add_number; - } else if (c != '+') { - know(0); - } /* switch on unary operator */ - break; - - default: /* unary on non-absolute is unsuported */ - if (!SEG_NORMAL(operand(expressionP))) - { - as_bad("Unary operator %c ignored because bad operand follows", c); - break; - } - /* Fall through for normal segments ****/ - case SEG_PASS1: - case SEG_UNKNOWN: - 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; - break; - } - /* Expression undisturbed from operand(). */ - } - } - else if (c == '\'') - { - /* - * 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; - } - else - { - /* can't imagine any other kind of operand */ - expressionP->X_seg = SEG_ABSENT; - input_line_pointer --; - md_operand (expressionP); - } - /* - * 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; -{ - switch (expressionP->X_seg) { - case SEG_ABSENT: - case SEG_PASS1: - expressionP->X_add_symbol = NULL; - expressionP->X_subtract_symbol = NULL; - expressionP->X_add_number = 0; - break; - - case SEG_BIG: - case SEG_ABSOLUTE: - expressionP->X_subtract_symbol = NULL; - expressionP->X_add_symbol = NULL; - break; - - case SEG_UNKNOWN: - expressionP->X_subtract_symbol = NULL; - break; - - case SEG_DIFFERENCE: - /* - * 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 - && SEG_NORMAL (S_GET_SEGMENT (expressionP->X_add_symbol)) - && 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 = SEG_ABSOLUTE; - } - break; - - case SEG_REGISTER: - expressionP->X_add_symbol = NULL; - expressionP->X_subtract_symbol = NULL; - break; - - default: - if (SEG_NORMAL(expressionP->X_seg)) { - expressionP->X_subtract_symbol = NULL; - } - else { - BAD_CASE (expressionP->X_seg); - } - break; - } -} /* clean_up_expression() */ - -/* - * 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 - know((* symbol_1_PP) == NULL || (S_GET_SEGMENT(*symbol_1_PP) == SEG_TEXT) || (S_GET_SEGMENT(*symbol_1_PP) == SEG_DATA) || (S_GET_SEGMENT(*symbol_1_PP) == SEG_BSS) || (!S_IS_DEFINED(* symbol_1_PP))); - know(symbol_2_P == NULL || (S_GET_SEGMENT(symbol_2_P) == SEG_TEXT) || (S_GET_SEGMENT(symbol_2_P) == SEG_DATA) || (S_GET_SEGMENT(symbol_2_P) == SEG_BSS) || (!S_IS_DEFINED(symbol_2_P))); -#endif - if (* symbol_1_PP) - { - if (!S_IS_DEFINED(* symbol_1_PP)) - { - if (symbol_2_P) - { - return_value = SEG_PASS1; - * symbol_1_PP = NULL; - } - else - { - know(!S_IS_DEFINED(* symbol_1_PP)); - return_value = SEG_UNKNOWN; - } - } - else - { - if (symbol_2_P) - { - if (!S_IS_DEFINED(symbol_2_P)) - { - * symbol_1_PP = NULL; - return_value = SEG_PASS1; - } - 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 = SEG_ABSOLUTE; - } - } - 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 = SEG_ABSOLUTE; - } - } -#ifndef MANY_SEGMENTS - 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); -#endif - know((*symbol_1_PP) == NULL || (S_GET_SEGMENT(*symbol_1_PP) == return_value)); - return (return_value); -} /* expr_part() */ - -void ps (s) -symbolS *s; -{ - fprintf (stdout, "%s type %s%s", - S_GET_NAME(s), - S_IS_EXTERNAL(s) ? "EXTERNAL " : "", - segment_name(S_GET_SEGMENT(s))); -} -void pe (e) -expressionS *e; -{ - fprintf (stdout, " segment %s\n", segment_name (e->X_seg)); - fprintf (stdout, " add_number %d (%x)\n", - e->X_add_number, e->X_add_number); - if (e->X_add_symbol) { - fprintf (stdout, " add_symbol "); - ps (e->X_add_symbol); - fprintf (stdout, "\n"); - } - if (e->X_subtract_symbol) { - fprintf (stdout, " sub_symbol "); - ps (e->X_subtract_symbol); - fprintf (stdout, "\n"); - } -} - -/* 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 u_char c_left; /* 1st operator character. */ - register operatorT op_right; - register u_char c_right; - -#ifndef __CHAR_UNSIGNED__ - know(rank >= 0); -#endif - (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 (SEG_ABSENT == 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 == '>')) { - 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 == SEG_PASS1 || right.X_seg == SEG_PASS1) { - resultP->X_seg = SEG_PASS1; - } else { - 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 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 = SEG_DIFFERENCE; - } - op_left = O_add; - } - - if (op_left == O_add) { - segT seg1; - segT seg2; -#ifndef MANY_SEGMENTS - 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); -#endif - clean_up_expression(& right); - clean_up_expression(resultP); - -#ifdef PIC -/* XXX - kludge here to accomodate "_GLOBAL_OFFSET_TABLE + (x - y)" - * expressions: this only works for this special case, the - * _GLOBAL_OFFSET_TABLE thing *must* be the left operand, the whole - * expression is given the segment of right expression (always a DIFFERENCE, - * which should get resolved by fixup_segment()) - */ - if (resultP->X_got_symbol && - right.X_add_symbol != NULL && - right.X_subtract_symbol != NULL) { - resultP->X_add_symbol = right.X_add_symbol; - resultP->X_subtract_symbol = right.X_subtract_symbol; - seg1 = S_GET_SEGMENT(right.X_add_symbol); - seg2 = S_GET_SEGMENT(right.X_subtract_symbol); - resultP->X_seg = right.X_seg; - } else { -#endif - seg1 = expr_part(&resultP->X_add_symbol, right.X_add_symbol); - seg2 = expr_part(&resultP->X_subtract_symbol, right.X_subtract_symbol); -#ifdef PIC - } -#endif - if (seg1 == SEG_PASS1 || seg2 == SEG_PASS1) { - need_pass_2 = 1; - resultP->X_seg = SEG_PASS1; - } else if (seg2 == SEG_ABSOLUTE) - resultP->X_seg = seg1; - else if (seg1 != SEG_UNKNOWN - && seg1 != SEG_ABSOLUTE - && seg2 != SEG_UNKNOWN - && seg1 != seg2) { - know(seg2 != SEG_ABSOLUTE); - know(resultP->X_subtract_symbol); -#ifndef MANY_SEGMENTS - know(seg1 == SEG_TEXT || seg1 == SEG_DATA || seg1 == SEG_BSS); - know(seg2 == SEG_TEXT || seg2 == SEG_DATA || seg2 == SEG_BSS); -#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 = SEG_ABSOLUTE; - /* Clean_up_expression() will do the rest. */ - } else - resultP->X_seg = SEG_DIFFERENCE; - - resultP->X_add_number += right.X_add_number; - clean_up_expression(resultP); - } else { /* Not +. */ - if (resultP->X_seg == SEG_UNKNOWN || right.X_seg == SEG_UNKNOWN) { - resultP->X_seg = SEG_PASS1; - need_pass_2 = 1; - } else { - 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_bad("Relocation error. Absolute 0 assumed."); - resultP->X_seg = SEG_ABSOLUTE; - 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); -} /* expr() */ - -/* - * 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; - -} -/* - * Local Variables: - * comment-column: 0 - * fill-column: 131 - * End: - */ - -/* end of expr.c */ |