X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gas%2Fexpr.h;h=c7b97da429464d426eea979c00b2bb49fd94cf31;hb=bccbc0aa84e92cb7d48e8221552bd4edcb876811;hp=350215e503b0530062f35efa22c27f1a58b25131;hpb=3a69b3aca678a3caf3ade7f9d42d18233b097ec6;p=deliverable%2Fbinutils-gdb.git diff --git a/gas/expr.h b/gas/expr.h index 350215e503..c7b97da429 100644 --- a/gas/expr.h +++ b/gas/expr.h @@ -1,79 +1,124 @@ /* expr.h -> header file for expr.c - Copyright (C) 1987 Free Software Foundation, Inc. + Copyright (C) 1987, 1992, 1993 Free Software Foundation, Inc. -This file is part of GAS, the GNU Assembler. + 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) -any later version. + 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. + 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. */ - -/* - * Abbreviations (mnemonics). - * - * O operator - * Q quantity, operand - * X eXpression - */ + 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. */ /* * By popular demand, we define a struct to represent an expression. * This will no doubt mutate as expressions become baroque. * - * Currently, we support expressions like "foo-bar+42". - * In other words we permit a (possibly undefined) minuend, a - * (possibly undefined) subtrahend and an (absolute) augend. - * RMS says this is so we can have 1-pass assembly for any compiler - * emmissions, and a 'case' statement might emit 'undefined1 - undefined2'. + * Currently, we support expressions like "foo OP bar + 42". In other + * words we permit a (possibly undefined) symbol, a (possibly + * undefined) symbol and the operation used to combine the symbols, + * and an (absolute) augend. RMS says this is so we can have 1-pass + * assembly for any compiler emissions, and a 'case' statement might + * emit 'undefined1 - undefined2'. * - * To simplify table-driven dispatch, we also have a "segment" for the - * entire expression. That way we don't require complex reasoning about - * whether particular components are defined; and we can change component - * semantics without re-working all the dispatch tables in the assembler. - * In other words the "type" of an expression is its segment. + * The type of an expression used to be stored as a segment. That got + * confusing because it overloaded the concept of a segment. I added + * an operator field, instead. */ -typedef struct -{ - symbolS *X_add_symbol; /* foo */ - symbolS *X_subtract_symbol; /* bar */ - long X_add_number; /* 42. Must be signed. */ - segT X_seg; /* What segment (expr type)? */ -} -expressionS; +/* This is the type of an expression. The operator types are also + used while parsing an expression. - /* result should be type (expressionS *). */ -#define expression(result) expr(0,result) + NOTE: This enumeration must match the op_rank array in expr.c. */ - /* If an expression is SEG_BIG, look here */ - /* for its value. These common data may */ - /* be clobbered whenever expr() is called. */ -extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */ - /* Enough to hold most precise flonum. */ -extern LITTLENUM_TYPE generic_bignum []; /* Bignums returned here. */ -#define SIZE_OF_LARGE_NUMBER (20) /* Number of littlenums in above. */ +typedef enum +{ + /* An illegal expression. */ + O_illegal, + /* A nonexistent expression. */ + O_absent, + /* X_add_number (a constant expression). */ + O_constant, + /* X_add_symbol + X_add_number. */ + O_symbol, + /* A register (X_add_number is register number). */ + O_register, + /* A big value. If X_add_number is negative or 0, the value is in + generic_floating_point_number. Otherwise the value is in + generic_bignum, and X_add_number is the number of LITTLENUMs in + the value. */ + O_big, + /* (- X_add_symbol) + X_add_number. */ + O_uminus, + /* (~ X_add_symbol) + X_add_number. */ + O_bit_not, + /* (X_add_symbol * X_op_symbol) + X_add_number. */ + O_multiply, + /* (X_add_symbol / X_op_symbol) + X_add_number. */ + O_divide, + /* X_add_symbol % X_op_symbol) + X_add_number. */ + O_modulus, + /* X_add_symbol << X_op_symbol) + X_add_number. */ + O_left_shift, + /* X_add_symbol >> X_op_symbol) + X_add_number. */ + O_right_shift, + /* X_add_symbol | X_op_symbol) + X_add_number. */ + O_bit_inclusive_or, + /* X_add_symbol |~ X_op_symbol) + X_add_number. */ + O_bit_or_not, + /* X_add_symbol ^ X_op_symbol) + X_add_number. */ + O_bit_exclusive_or, + /* X_add_symbol & X_op_symbol) + X_add_number. */ + O_bit_and, + /* X_add_symbol + X_op_symbol) + X_add_number. */ + O_add, + /* X_add_symbol - X_op_symbol) + X_add_number. */ + O_subtract +} operatorT; + +typedef struct expressionS +{ + /* The type of the expression. */ + operatorT X_op; + /* The main symbol. */ + struct symbol *X_add_symbol; + /* The second symbol, if needed. */ + struct symbol *X_op_symbol; + /* A number to add. */ + offsetT X_add_number; + /* Non-zero if X_add_number should be regarded as unsigned. This is + only valid for O_constant expressions. It is only used when an + O_constant must be extended into a bignum (i.e., it is not used + when performing arithmetic on these values). + FIXME: This field is not set very reliably. + If we ever need more flags here, we can make them bitfields. */ + int X_unsigned; +} expressionS; + +/* "result" should be type (expressionS *). */ +#define expression(result) expr (0, result) + +/* If an expression is O_big, look here for its value. These common + data may be clobbered whenever expr() is called. */ +/* Flonums returned here. Big enough to hold most precise flonum. */ +extern FLONUM_TYPE generic_floating_point_number; +/* Bignums returned here. */ +extern LITTLENUM_TYPE generic_bignum[]; +/* Number of littlenums in above. */ +#define SIZE_OF_LARGE_NUMBER (20) typedef char operator_rankT; -#ifdef __STDC__ - -char get_symbol_end(void); -segT expr(int rank, expressionS *resultP); - -#else /* __STDC__ */ - -char get_symbol_end(); -segT expr(); - -#endif /* __STDC__ */ +char get_symbol_end PARAMS ((void)); +segT expr PARAMS ((int rank, expressionS * resultP)); +unsigned int get_single_number PARAMS ((void)); +symbolS *make_expr_symbol PARAMS ((expressionS * expressionP)); -/* end: expr.h */ +/* end of expr.h */