From 648acaa0c0427463876773336c87af4d18be8a76 Mon Sep 17 00:00:00 2001 From: Ken Raeburn Date: Wed, 28 Sep 1994 19:09:16 +0000 Subject: [PATCH] * expr.c (make_expr_symbol): No longer static. Use symbol_create, not symbol_new, for symbols holding expression values. * expr.h (make_expr_symbol): Move declaration here. --- gas/ChangeLog | 6 +++ gas/expr.h | 106 +++++++++++++++++++++++++++++++++++++------------- 2 files changed, 85 insertions(+), 27 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index 50df2165399..efca0564048 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,9 @@ +Wed Sep 28 14:56:39 1994 Ken Raeburn + + * expr.c (make_expr_symbol): No longer static. Use symbol_create, + not symbol_new, for symbols holding expression values. + * expr.h (make_expr_symbol): Move declaration here. + Wed Sep 28 11:50:40 1994 Ian Lance Taylor (ian@sanguine.cygnus.com) * config/tc-mips.c: Include subsegs.h. diff --git a/gas/expr.h b/gas/expr.h index d98b486d19e..c7b97da4294 100644 --- a/gas/expr.h +++ b/gas/expr.h @@ -1,5 +1,5 @@ /* expr.h -> header file for expr.c - Copyright (C) 1987, 1992 Free Software Foundation, Inc. + Copyright (C) 1987, 1992, 1993 Free Software Foundation, Inc. This file is part of GAS, the GNU Assembler. @@ -17,44 +17,95 @@ 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 - */ - /* * 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 - * emissions, 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 +/* This is the type of an expression. The operator types are also + used while parsing an expression. + + NOTE: This enumeration must match the op_rank array in expr.c. */ + +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 { - struct symbol *X_add_symbol; /* "foo", above */ - struct symbol *X_subtract_symbol; /* "bar", above */ - offsetT X_add_number; /* 42, above -- must be signed */ - /* What segment (expr type)? */ - segT X_seg; + /* 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) +#define expression(result) expr (0, result) -/* If an expression is SEG_BIG, look here for its value. These common +/* 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; @@ -68,5 +119,6 @@ typedef char operator_rankT; 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 of expr.h */ -- 2.30.2