[thirdparty/binutils-gdb.git] / gdb / expression.h

/* Definitions for expressions stored in reversed prefix form, for GDB.

   Copyright (C) 1986, 1989, 1992, 1994, 2000, 2003, 2005, 2007
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#if !defined (EXPRESSION_H)
#define EXPRESSION_H 1


#include "symtab.h"		/* Needed for "struct block" type. */
#include "doublest.h"		/* Needed for DOUBLEST.  */


/* Definitions for saved C expressions.  */

/* An expression is represented as a vector of union exp_element's.
   Each exp_element is an opcode, except that some opcodes cause
   the following exp_element to be treated as a long or double constant
   or as a variable.  The opcodes are obeyed, using a stack for temporaries.
   The value is left on the temporary stack at the end.  */

/* When it is necessary to include a string,
   it can occupy as many exp_elements as it needs.
   We find the length of the string using strlen,
   divide to find out how many exp_elements are used up,
   and skip that many.  Strings, like numbers, are indicated
   by the preceding opcode.  */

enum exp_opcode
  {
    /* Used when it's necessary to pass an opcode which will be ignored,
       or to catch uninitialized values.  */
    OP_NULL,

/* BINOP_... operate on two values computed by following subexpressions,
   replacing them by one result value.  They take no immediate arguments.  */

    BINOP_ADD,			/* + */
    BINOP_SUB,			/* - */
    BINOP_MUL,			/* * */
    BINOP_DIV,			/* / */
    BINOP_REM,			/* % */
    BINOP_MOD,			/* mod (Knuth 1.2.4) */
    BINOP_LSH,			/* << */
    BINOP_RSH,			/* >> */
    BINOP_LOGICAL_AND,		/* && */
    BINOP_LOGICAL_OR,		/* || */
    BINOP_BITWISE_AND,		/* & */
    BINOP_BITWISE_IOR,		/* | */
    BINOP_BITWISE_XOR,		/* ^ */
    BINOP_EQUAL,		/* == */
    BINOP_NOTEQUAL,		/* != */
    BINOP_LESS,			/* < */
    BINOP_GTR,			/* > */
    BINOP_LEQ,			/* <= */
    BINOP_GEQ,			/* >= */
    BINOP_REPEAT,		/* @ */
    BINOP_ASSIGN,		/* = */
    BINOP_COMMA,		/* , */
    BINOP_SUBSCRIPT,		/* x[y] */
    BINOP_EXP,			/* Exponentiation */

    /* C++.  */

    BINOP_MIN,			/* <? */
    BINOP_MAX,			/* >? */

    /* STRUCTOP_MEMBER is used for pointer-to-member constructs.
       X . * Y translates into X STRUCTOP_MEMBER Y.  */
    STRUCTOP_MEMBER,

    /* STRUCTOP_MPTR is used for pointer-to-member constructs
       when X is a pointer instead of an aggregate.  */
    STRUCTOP_MPTR,

    /* end of C++.  */

    /* For Modula-2 integer division DIV */
    BINOP_INTDIV,

    BINOP_ASSIGN_MODIFY,	/* +=, -=, *=, and so on.
				   The following exp_element is another opcode,
				   a BINOP_, saying how to modify.
				   Then comes another BINOP_ASSIGN_MODIFY,
				   making three exp_elements in total.  */

    /* Modula-2 standard (binary) procedures */
    BINOP_VAL,
    BINOP_INCL,
    BINOP_EXCL,

    /* Concatenate two operands, such as character strings or bitstrings.
       If the first operand is a integer expression, then it means concatenate
       the second operand with itself that many times. */
    BINOP_CONCAT,

    /* For (the deleted) Chill and Pascal. */
    BINOP_IN,			/* Returns 1 iff ARG1 IN ARG2. */

    /* This is the "colon operator" used various places in (the
       deleted) Chill. */
    BINOP_RANGE,

    /* This must be the highest BINOP_ value, for expprint.c.  */
    BINOP_END,

    /* Operates on three values computed by following subexpressions.  */
    TERNOP_COND,		/* ?: */

    /* A sub-string/sub-array.  (the deleted) Chill syntax:
       OP1(OP2:OP3).  Return elements OP2 through OP3 of OP1.  */
    TERNOP_SLICE,

    /* A sub-string/sub-array.  (The deleted) Chill syntax: OP1(OP2 UP
       OP3).  Return OP3 elements of OP1, starting with element
       OP2. */
    TERNOP_SLICE_COUNT,

    /* Multidimensional subscript operator, such as Modula-2 x[a,b,...].
       The dimensionality is encoded in the operator, like the number of
       function arguments in OP_FUNCALL, I.E. <OP><dimension><OP>.
       The value of the first following subexpression is subscripted
       by each of the next following subexpressions, one per dimension. */
    MULTI_SUBSCRIPT,

    /* The OP_... series take immediate following arguments.
       After the arguments come another OP_... (the same one)
       so that the grouping can be recognized from the end.  */

    /* OP_LONG is followed by a type pointer in the next exp_element
       and the long constant value in the following exp_element.
       Then comes another OP_LONG.
       Thus, the operation occupies four exp_elements.  */
    OP_LONG,

    /* OP_DOUBLE is similar but takes a DOUBLEST constant instead of a long.  */
    OP_DOUBLE,

    /* OP_VAR_VALUE takes one struct block * in the following element,
       and one struct symbol * in the following exp_element, followed by
       another OP_VAR_VALUE, making four exp_elements.  If the block is
       non-NULL, evaluate the symbol relative to the innermost frame
       executing in that block; if the block is NULL use the selected frame.  */
    OP_VAR_VALUE,

    /* OP_LAST is followed by an integer in the next exp_element.
       The integer is zero for the last value printed,
       or it is the absolute number of a history element.
       With another OP_LAST at the end, this makes three exp_elements.  */
    OP_LAST,

    /* OP_REGISTER is followed by a string in the next exp_element.
       This is the name of a register to fetch.  */
    OP_REGISTER,

    /* OP_INTERNALVAR is followed by an internalvar ptr in the next exp_element.
       With another OP_INTERNALVAR at the end, this makes three exp_elements.  */
    OP_INTERNALVAR,

    /* OP_FUNCALL is followed by an integer in the next exp_element.
       The integer is the number of args to the function call.
       That many plus one values from following subexpressions
       are used, the first one being the function.
       The integer is followed by a repeat of OP_FUNCALL,
       making three exp_elements.  */
    OP_FUNCALL,

    /* OP_OBJC_MSGCALL is followed by a string in the next exp_element and then an
       integer.  The string is the selector string.  The integer is the number
       of arguments to the message call.  That many plus one values are used, 
       the first one being the object pointer.  This is an Objective C message */
    OP_OBJC_MSGCALL,

    /* This is EXACTLY like OP_FUNCALL but is semantically different.  
       In F77, array subscript expressions, substring expressions
       and function calls are  all exactly the same syntactically. They may 
       only be disambiguated at runtime.  Thus this operator, which 
       indicates that we have found something of the form <name> ( <stuff> ) */
    OP_F77_UNDETERMINED_ARGLIST,

    /* The following OP is a special one, it introduces a F77 complex
       literal. It is followed by exactly two args that are doubles.  */
    OP_COMPLEX,

    /* OP_STRING represents a string constant.
       Its format is the same as that of a STRUCTOP, but the string
       data is just made into a string constant when the operation
       is executed.  */
    OP_STRING,

    /* OP_BITSTRING represents a packed bitstring constant.
       Its format is the same as that of a STRUCTOP, but the bitstring
       data is just made into a bitstring constant when the operation
       is executed.  */
    OP_BITSTRING,

    /* OP_ARRAY creates an array constant out of the following subexpressions.
       It is followed by two exp_elements, the first containing an integer
       that is the lower bound of the array and the second containing another
       integer that is the upper bound of the array.  The second integer is
       followed by a repeat of OP_ARRAY, making four exp_elements total.
       The bounds are used to compute the number of following subexpressions
       to consume, as well as setting the bounds in the created array constant.
       The type of the elements is taken from the type of the first subexp,
       and they must all match. */
    OP_ARRAY,

    /* UNOP_CAST is followed by a type pointer in the next exp_element.
       With another UNOP_CAST at the end, this makes three exp_elements.
       It casts the value of the following subexpression.  */
    UNOP_CAST,

    /* UNOP_MEMVAL is followed by a type pointer in the next exp_element
       With another UNOP_MEMVAL at the end, this makes three exp_elements.
       It casts the contents of the word addressed by the value of the
       following subexpression.  */
    UNOP_MEMVAL,

    /* UNOP_MEMVAL_TLS is followed by a `struct objfile' pointer in the next
       exp_element and a type pointer in the following exp_element.
       With another UNOP_MEMVAL_TLS at the end, this makes four exp_elements.
       It casts the contents of the word offsetted by the value of the
       following subexpression from the TLS specified by `struct objfile'.  */
    UNOP_MEMVAL_TLS,

    /* UNOP_... operate on one value from a following subexpression
       and replace it with a result.  They take no immediate arguments.  */

    UNOP_NEG,			/* Unary - */
    UNOP_LOGICAL_NOT,		/* Unary ! */
    UNOP_COMPLEMENT,		/* Unary ~ */
    UNOP_IND,			/* Unary * */
    UNOP_ADDR,			/* Unary & */
    UNOP_PREINCREMENT,		/* ++ before an expression */
    UNOP_POSTINCREMENT,		/* ++ after an expression */
    UNOP_PREDECREMENT,		/* -- before an expression */
    UNOP_POSTDECREMENT,		/* -- after an expression */
    UNOP_SIZEOF,		/* Unary sizeof (followed by expression) */

    UNOP_PLUS,			/* Unary plus */

    UNOP_CAP,			/* Modula-2 standard (unary) procedures */
    UNOP_CHR,
    UNOP_ORD,
    UNOP_ABS,
    UNOP_FLOAT,
    UNOP_HIGH,
    UNOP_MAX,
    UNOP_MIN,
    UNOP_ODD,
    UNOP_TRUNC,

    /* (The deleted) Chill builtin functions.  */
    UNOP_LOWER, UNOP_UPPER, UNOP_LENGTH, UNOP_CARD, UNOP_CHMAX, UNOP_CHMIN,

    OP_BOOL,			/* Modula-2 builtin BOOLEAN type */
    OP_M2_STRING,		/* Modula-2 string constants */

    /* STRUCTOP_... operate on a value from a following subexpression
       by extracting a structure component specified by a string
       that appears in the following exp_elements (as many as needed).
       STRUCTOP_STRUCT is used for "." and STRUCTOP_PTR for "->".
       They differ only in the error message given in case the value is
       not suitable or the structure component specified is not found.

       The length of the string follows the opcode, followed by
       BYTES_TO_EXP_ELEM(length) elements containing the data of the
       string, followed by the length again and the opcode again.  */

    STRUCTOP_STRUCT,
    STRUCTOP_PTR,

    /* C++: OP_THIS is just a placeholder for the class instance variable.
       It just comes in a tight (OP_THIS, OP_THIS) pair.  */
    OP_THIS,

    /* Objective-C: OP_OBJC_SELF is just a placeholder for the class instance
       variable.  It just comes in a tight (OP_OBJC_SELF, OP_OBJC_SELF) pair.  */
    OP_OBJC_SELF,

    /* Objective C: "@selector" pseudo-operator */
    OP_OBJC_SELECTOR,

    /* OP_SCOPE surrounds a type name and a field name.  The type
       name is encoded as one element, but the field name stays as
       a string, which, of course, is variable length.  */
    OP_SCOPE,

    /* Used to represent named structure field values in brace
       initializers (or tuples as they are called in (the deleted)
       Chill).

       The gcc C syntax is NAME:VALUE or .NAME=VALUE, the (the
       deleted) Chill syntax is .NAME:VALUE.  Multiple labels (as in
       the (the deleted) Chill syntax .NAME1,.NAME2:VALUE) is
       represented as if it were .NAME1:(.NAME2:VALUE) (though that is
       not valid (the deleted) Chill syntax).

       The NAME is represented as for STRUCTOP_STRUCT;  VALUE follows. */
    OP_LABELED,

    /* OP_TYPE is for parsing types, and used with the "ptype" command
       so we can look up types that are qualified by scope, either with
       the GDB "::" operator, or the Modula-2 '.' operator. */
    OP_TYPE,

    /* An un-looked-up identifier. */
    OP_NAME,

    /* An Objective C Foundation Class NSString constant */
    OP_OBJC_NSSTRING,

    /* A F90 array range operator (for "exp:exp", "exp:", ":exp" and ":").  */
    OP_F90_RANGE,

     /* First extension operator.  Individual language modules define
        extra operators they need as constants with values 
        OP_LANGUAGE_SPECIFIC0 + k, for k >= 0, using a separate 
        enumerated type definition:
           enum foo_extension_operator {
             BINOP_MOGRIFY = OP_EXTENDED0,
 	     BINOP_FROB,
 	     ...
           };      */
    OP_EXTENDED0,
  
    /* Last possible extension operator.  Defined to provide an
       explicit and finite number of extended operators. */
    OP_EXTENDED_LAST = 0xff
    /* NOTE: Eventually, we expect to convert to an object-oriented 
       formulation for expression operators that does away with the
       need for these extension operators, and indeed for this
       entire enumeration type.  Therefore, consider the OP_EXTENDED
       definitions to be a temporary measure. */
  };

union exp_element
  {
    enum exp_opcode opcode;
    struct symbol *symbol;
    LONGEST longconst;
    DOUBLEST doubleconst;
    /* Really sizeof (union exp_element) characters (or less for the last
       element of a string).  */
    char string;
    struct type *type;
    struct internalvar *internalvar;
    struct block *block;
    struct objfile *objfile;
  };

struct expression
  {
    const struct language_defn *language_defn;	/* language it was entered in */
    int nelts;
    union exp_element elts[1];
  };

/* Macros for converting between number of expression elements and bytes
   to store that many expression elements. */

#define EXP_ELEM_TO_BYTES(elements) \
    ((elements) * sizeof (union exp_element))
#define BYTES_TO_EXP_ELEM(bytes) \
    (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element))

/* From parse.c */

extern struct expression *parse_expression (char *);

extern struct expression *parse_expression_in_context (char *, int);

extern struct expression *parse_exp_1 (char **, struct block *, int);

/* The innermost context required by the stack and register variables
   we've encountered so far.  To use this, set it to NULL, then call
   parse_<whatever>, then look at it.  */
extern struct block *innermost_block;

/* From eval.c */

/* Values of NOSIDE argument to eval_subexp.  */

enum noside
  {
    EVAL_NORMAL,
    EVAL_SKIP,			/* Only effect is to increment pos.  */
    EVAL_AVOID_SIDE_EFFECTS	/* Don't modify any variables or
				   call any functions.  The value
				   returned will have the correct
				   type, and will have an
				   approximately correct lvalue
				   type (inaccuracy: anything that is
				   listed as being in a register in
				   the function in which it was
				   declared will be lval_register).  */
  };

extern struct value *evaluate_subexp_standard
  (struct type *, struct expression *, int *, enum noside);

/* From expprint.c */

extern void print_expression (struct expression *, struct ui_file *);

extern char *op_string (enum exp_opcode);

extern void dump_raw_expression (struct expression *, struct ui_file *, char *);
extern void dump_prefix_expression (struct expression *, struct ui_file *);

#endif /* !defined (EXPRESSION_H) */
Commit	Line	Data
c906108c	1	/* Definitions for expressions stored in reversed prefix form, for GDB.
1bac305b	2
6aba47ca DJ	3	Copyright (C) 1986, 1989, 1992, 1994, 2000, 2003, 2005, 2007
6aba47ca DJ	4	Free Software Foundation, Inc.
c906108c	5
c5aa993b	6	This file is part of GDB.
c906108c	7
c5aa993b JM	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 2 of the License, or
	11	(at your option) any later version.
c906108c	12
c5aa993b JM	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
c906108c	17
c5aa993b JM	18	You should have received a copy of the GNU General Public License
c5aa993b JM	19	along with this program; if not, write to the Free Software
197e01b6 EZ	20	Foundation, Inc., 51 Franklin Street, Fifth Floor,
197e01b6 EZ	21	Boston, MA 02110-1301, USA. */
c906108c SS	22
	23	#if !defined (EXPRESSION_H)
	24	#define EXPRESSION_H 1
	25
	26
c5aa993b	27	#include "symtab.h" /* Needed for "struct block" type. */
d16aafd8	28	#include "doublest.h" /* Needed for DOUBLEST. */
c906108c SS	29
	30
	31	/* Definitions for saved C expressions. */
	32
	33	/* An expression is represented as a vector of union exp_element's.
	34	Each exp_element is an opcode, except that some opcodes cause
	35	the following exp_element to be treated as a long or double constant
	36	or as a variable. The opcodes are obeyed, using a stack for temporaries.
	37	The value is left on the temporary stack at the end. */
	38
	39	/* When it is necessary to include a string,
	40	it can occupy as many exp_elements as it needs.
	41	We find the length of the string using strlen,
	42	divide to find out how many exp_elements are used up,
	43	and skip that many. Strings, like numbers, are indicated
	44	by the preceding opcode. */
	45
	46	enum exp_opcode
c5aa993b JM	47	{
	48	/* Used when it's necessary to pass an opcode which will be ignored,
	49	or to catch uninitialized values. */
	50	OP_NULL,
c906108c SS	51
	52	/* BINOP_... operate on two values computed by following subexpressions,
	53	replacing them by one result value. They take no immediate arguments. */
	54
c5aa993b JM	55	BINOP_ADD, /* + */
	56	BINOP_SUB, /* - */
	57	BINOP_MUL, /* * */
	58	BINOP_DIV, /* / */
	59	BINOP_REM, /* % */
	60	BINOP_MOD, /* mod (Knuth 1.2.4) */
	61	BINOP_LSH, /* << */
	62	BINOP_RSH, /* >> */
	63	BINOP_LOGICAL_AND, /* && */
	64	BINOP_LOGICAL_OR, /* \|\| */
	65	BINOP_BITWISE_AND, /* & */
	66	BINOP_BITWISE_IOR, /* \| */
	67	BINOP_BITWISE_XOR, /* ^ */
	68	BINOP_EQUAL, /* == */
	69	BINOP_NOTEQUAL, /* != */
	70	BINOP_LESS, /* < */
	71	BINOP_GTR, /* > */
	72	BINOP_LEQ, /* <= */
	73	BINOP_GEQ, /* >= */
	74	BINOP_REPEAT, /* @ */
	75	BINOP_ASSIGN, /* = */
	76	BINOP_COMMA, /* , */
	77	BINOP_SUBSCRIPT, /* x[y] */
	78	BINOP_EXP, /* Exponentiation */
	79
	80	/* C++. */
	81
	82	BINOP_MIN, /* <? */
	83	BINOP_MAX, /* >? */
c5aa993b JM	84
	85	/* STRUCTOP_MEMBER is used for pointer-to-member constructs.
	86	X . * Y translates into X STRUCTOP_MEMBER Y. */
	87	STRUCTOP_MEMBER,
	88
	89	/* STRUCTOP_MPTR is used for pointer-to-member constructs
	90	when X is a pointer instead of an aggregate. */
	91	STRUCTOP_MPTR,
	92
	93	/* end of C++. */
	94
	95	/* For Modula-2 integer division DIV */
	96	BINOP_INTDIV,
	97
	98	BINOP_ASSIGN_MODIFY, /* +=, -=, *=, and so on.
	99	The following exp_element is another opcode,
	100	a BINOP_, saying how to modify.
	101	Then comes another BINOP_ASSIGN_MODIFY,
	102	making three exp_elements in total. */
	103
	104	/* Modula-2 standard (binary) procedures */
	105	BINOP_VAL,
	106	BINOP_INCL,
	107	BINOP_EXCL,
	108
	109	/* Concatenate two operands, such as character strings or bitstrings.
	110	If the first operand is a integer expression, then it means concatenate
	111	the second operand with itself that many times. */
	112	BINOP_CONCAT,
	113
1b831c93	114	/* For (the deleted) Chill and Pascal. */
c5aa993b JM	115	BINOP_IN, /* Returns 1 iff ARG1 IN ARG2. */
c5aa993b JM	116
1b831c93 AC	117	/* This is the "colon operator" used various places in (the
1b831c93 AC	118	deleted) Chill. */
c5aa993b JM	119	BINOP_RANGE,
	120
	121	/* This must be the highest BINOP_ value, for expprint.c. */
	122	BINOP_END,
	123
	124	/* Operates on three values computed by following subexpressions. */
	125	TERNOP_COND, /* ?: */
	126
1b831c93	127	/* A sub-string/sub-array. (the deleted) Chill syntax:
db034ac5	128	OP1(OP2:OP3). Return elements OP2 through OP3 of OP1. */
c5aa993b JM	129	TERNOP_SLICE,
c5aa993b JM	130
1b831c93 AC	131	/* A sub-string/sub-array. (The deleted) Chill syntax: OP1(OP2 UP
	132	OP3). Return OP3 elements of OP1, starting with element
	133	OP2. */
c5aa993b JM	134	TERNOP_SLICE_COUNT,
	135
	136	/* Multidimensional subscript operator, such as Modula-2 x[a,b,...].
	137	The dimensionality is encoded in the operator, like the number of
	138	function arguments in OP_FUNCALL, I.E. <OP><dimension><OP>.
	139	The value of the first following subexpression is subscripted
	140	by each of the next following subexpressions, one per dimension. */
	141	MULTI_SUBSCRIPT,
	142
	143	/* The OP_... series take immediate following arguments.
	144	After the arguments come another OP_... (the same one)
	145	so that the grouping can be recognized from the end. */
	146
	147	/* OP_LONG is followed by a type pointer in the next exp_element
	148	and the long constant value in the following exp_element.
	149	Then comes another OP_LONG.
	150	Thus, the operation occupies four exp_elements. */
	151	OP_LONG,
	152
	153	/* OP_DOUBLE is similar but takes a DOUBLEST constant instead of a long. */
	154	OP_DOUBLE,
	155
	156	/* OP_VAR_VALUE takes one struct block * in the following element,
	157	and one struct symbol * in the following exp_element, followed by
	158	another OP_VAR_VALUE, making four exp_elements. If the block is
	159	non-NULL, evaluate the symbol relative to the innermost frame
	160	executing in that block; if the block is NULL use the selected frame. */
	161	OP_VAR_VALUE,
	162
	163	/* OP_LAST is followed by an integer in the next exp_element.
	164	The integer is zero for the last value printed,
	165	or it is the absolute number of a history element.
	166	With another OP_LAST at the end, this makes three exp_elements. */
	167	OP_LAST,
	168
67f3407f DJ	169	/* OP_REGISTER is followed by a string in the next exp_element.
67f3407f DJ	170	This is the name of a register to fetch. */
c5aa993b JM	171	OP_REGISTER,
	172
	173	/* OP_INTERNALVAR is followed by an internalvar ptr in the next exp_element.
	174	With another OP_INTERNALVAR at the end, this makes three exp_elements. */
	175	OP_INTERNALVAR,
	176
	177	/* OP_FUNCALL is followed by an integer in the next exp_element.
	178	The integer is the number of args to the function call.
	179	That many plus one values from following subexpressions
	180	are used, the first one being the function.
	181	The integer is followed by a repeat of OP_FUNCALL,
	182	making three exp_elements. */
	183	OP_FUNCALL,
	184
646df18d	185	/* OP_OBJC_MSGCALL is followed by a string in the next exp_element and then an
b01ab485 AF	186	integer. The string is the selector string. The integer is the number
	187	of arguments to the message call. That many plus one values are used,
	188	the first one being the object pointer. This is an Objective C message */
646df18d	189	OP_OBJC_MSGCALL,
b01ab485	190
c5aa993b JM	191	/* This is EXACTLY like OP_FUNCALL but is semantically different.
	192	In F77, array subscript expressions, substring expressions
	193	and function calls are all exactly the same syntactically. They may
f2047500	194	only be disambiguated at runtime. Thus this operator, which
c5aa993b JM	195	indicates that we have found something of the form <name> ( <stuff> ) */
	196	OP_F77_UNDETERMINED_ARGLIST,
	197
	198	/* The following OP is a special one, it introduces a F77 complex
	199	literal. It is followed by exactly two args that are doubles. */
	200	OP_COMPLEX,
	201
	202	/* OP_STRING represents a string constant.
	203	Its format is the same as that of a STRUCTOP, but the string
	204	data is just made into a string constant when the operation
	205	is executed. */
	206	OP_STRING,
	207
	208	/* OP_BITSTRING represents a packed bitstring constant.
	209	Its format is the same as that of a STRUCTOP, but the bitstring
	210	data is just made into a bitstring constant when the operation
	211	is executed. */
	212	OP_BITSTRING,
	213
	214	/* OP_ARRAY creates an array constant out of the following subexpressions.
	215	It is followed by two exp_elements, the first containing an integer
	216	that is the lower bound of the array and the second containing another
	217	integer that is the upper bound of the array. The second integer is
	218	followed by a repeat of OP_ARRAY, making four exp_elements total.
	219	The bounds are used to compute the number of following subexpressions
	220	to consume, as well as setting the bounds in the created array constant.
	221	The type of the elements is taken from the type of the first subexp,
	222	and they must all match. */
	223	OP_ARRAY,
	224
	225	/* UNOP_CAST is followed by a type pointer in the next exp_element.
	226	With another UNOP_CAST at the end, this makes three exp_elements.
	227	It casts the value of the following subexpression. */
	228	UNOP_CAST,
	229
	230	/* UNOP_MEMVAL is followed by a type pointer in the next exp_element
	231	With another UNOP_MEMVAL at the end, this makes three exp_elements.
	232	It casts the contents of the word addressed by the value of the
	233	following subexpression. */
	234	UNOP_MEMVAL,
	235
9e35dae4 DJ	236	/* UNOP_MEMVAL_TLS is followed by a `struct objfile' pointer in the next
	237	exp_element and a type pointer in the following exp_element.
	238	With another UNOP_MEMVAL_TLS at the end, this makes four exp_elements.
	239	It casts the contents of the word offsetted by the value of the
	240	following subexpression from the TLS specified by `struct objfile'. */
	241	UNOP_MEMVAL_TLS,
	242
c5aa993b JM	243	/* UNOP_... operate on one value from a following subexpression
	244	and replace it with a result. They take no immediate arguments. */
	245
	246	UNOP_NEG, /* Unary - */
	247	UNOP_LOGICAL_NOT, /* Unary ! */
	248	UNOP_COMPLEMENT, /* Unary ~ */
	249	UNOP_IND, /* Unary * */
	250	UNOP_ADDR, /* Unary & */
	251	UNOP_PREINCREMENT, /* ++ before an expression */
	252	UNOP_POSTINCREMENT, /* ++ after an expression */
	253	UNOP_PREDECREMENT, /* -- before an expression */
	254	UNOP_POSTDECREMENT, /* -- after an expression */
	255	UNOP_SIZEOF, /* Unary sizeof (followed by expression) */
	256
	257	UNOP_PLUS, /* Unary plus */
	258
	259	UNOP_CAP, /* Modula-2 standard (unary) procedures */
	260	UNOP_CHR,
	261	UNOP_ORD,
	262	UNOP_ABS,
	263	UNOP_FLOAT,
	264	UNOP_HIGH,
	265	UNOP_MAX,
	266	UNOP_MIN,
	267	UNOP_ODD,
	268	UNOP_TRUNC,
	269
1b831c93	270	/* (The deleted) Chill builtin functions. */
c5aa993b JM	271	UNOP_LOWER, UNOP_UPPER, UNOP_LENGTH, UNOP_CARD, UNOP_CHMAX, UNOP_CHMIN,
	272
	273	OP_BOOL, /* Modula-2 builtin BOOLEAN type */
	274	OP_M2_STRING, /* Modula-2 string constants */
	275
	276	/* STRUCTOP_... operate on a value from a following subexpression
	277	by extracting a structure component specified by a string
	278	that appears in the following exp_elements (as many as needed).
	279	STRUCTOP_STRUCT is used for "." and STRUCTOP_PTR for "->".
	280	They differ only in the error message given in case the value is
	281	not suitable or the structure component specified is not found.
	282
	283	The length of the string follows the opcode, followed by
	284	BYTES_TO_EXP_ELEM(length) elements containing the data of the
	285	string, followed by the length again and the opcode again. */
	286
	287	STRUCTOP_STRUCT,
	288	STRUCTOP_PTR,
	289
b01ab485	290	/* C++: OP_THIS is just a placeholder for the class instance variable.
c5aa993b JM	291	It just comes in a tight (OP_THIS, OP_THIS) pair. */
	292	OP_THIS,
	293
646df18d AF	294	/* Objective-C: OP_OBJC_SELF is just a placeholder for the class instance
	295	variable. It just comes in a tight (OP_OBJC_SELF, OP_OBJC_SELF) pair. */
	296	OP_OBJC_SELF,
b01ab485 AF	297
b01ab485 AF	298	/* Objective C: "@selector" pseudo-operator */
646df18d	299	OP_OBJC_SELECTOR,
b01ab485	300
c5aa993b JM	301	/* OP_SCOPE surrounds a type name and a field name. The type
	302	name is encoded as one element, but the field name stays as
	303	a string, which, of course, is variable length. */
	304	OP_SCOPE,
	305
db034ac5	306	/* Used to represent named structure field values in brace
1b831c93 AC	307	initializers (or tuples as they are called in (the deleted)
1b831c93 AC	308	Chill).
db034ac5	309
1b831c93 AC	310	The gcc C syntax is NAME:VALUE or .NAME=VALUE, the (the
	311	deleted) Chill syntax is .NAME:VALUE. Multiple labels (as in
	312	the (the deleted) Chill syntax .NAME1,.NAME2:VALUE) is
db034ac5	313	represented as if it were .NAME1:(.NAME2:VALUE) (though that is
1b831c93	314	not valid (the deleted) Chill syntax).
c5aa993b JM	315
	316	The NAME is represented as for STRUCTOP_STRUCT; VALUE follows. */
	317	OP_LABELED,
	318
	319	/* OP_TYPE is for parsing types, and used with the "ptype" command
	320	so we can look up types that are qualified by scope, either with
	321	the GDB "::" operator, or the Modula-2 '.' operator. */
	322	OP_TYPE,
	323
	324	/* An un-looked-up identifier. */
	325	OP_NAME,
	326
b01ab485	327	/* An Objective C Foundation Class NSString constant */
5f9769d1 PH	328	OP_OBJC_NSSTRING,
5f9769d1 PH	329
c3e308a8	330	/* A F90 array range operator (for "exp:exp", "exp:", ":exp" and ":"). */
0b4e1325 WZ	331	OP_F90_RANGE,
0b4e1325 WZ	332
5f9769d1 PH	333	/* First extension operator. Individual language modules define
	334	extra operators they need as constants with values
	335	OP_LANGUAGE_SPECIFIC0 + k, for k >= 0, using a separate
	336	enumerated type definition:
	337	enum foo_extension_operator {
	338	BINOP_MOGRIFY = OP_EXTENDED0,
	339	BINOP_FROB,
	340	...
	341	}; */
	342	OP_EXTENDED0,
	343
	344	/* Last possible extension operator. Defined to provide an
	345	explicit and finite number of extended operators. */
	346	OP_EXTENDED_LAST = 0xff
	347	/* NOTE: Eventually, we expect to convert to an object-oriented
	348	formulation for expression operators that does away with the
	349	need for these extension operators, and indeed for this
	350	entire enumeration type. Therefore, consider the OP_EXTENDED
	351	definitions to be a temporary measure. */
c5aa993b	352	};
c906108c SS	353
c906108c SS	354	union exp_element
c5aa993b JM	355	{
	356	enum exp_opcode opcode;
	357	struct symbol *symbol;
	358	LONGEST longconst;
	359	DOUBLEST doubleconst;
	360	/* Really sizeof (union exp_element) characters (or less for the last
	361	element of a string). */
	362	char string;
	363	struct type *type;
	364	struct internalvar *internalvar;
	365	struct block *block;
9e35dae4	366	struct objfile *objfile;
c5aa993b	367	};
c906108c SS	368
c906108c SS	369	struct expression
c5aa993b JM	370	{
	371	const struct language_defn language_defn; / language it was entered in */
	372	int nelts;
	373	union exp_element elts[1];
	374	};
c906108c SS	375
	376	/* Macros for converting between number of expression elements and bytes
	377	to store that many expression elements. */
	378
	379	#define EXP_ELEM_TO_BYTES(elements) \
	380	((elements) * sizeof (union exp_element))
	381	#define BYTES_TO_EXP_ELEM(bytes) \
	382	(((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element))
	383
	384	/* From parse.c */
	385
a14ed312	386	extern struct expression parse_expression (char );
c906108c	387
e85c3284 PH	388	extern struct expression parse_expression_in_context (char , int);
e85c3284 PH	389
a14ed312	390	extern struct expression parse_exp_1 (char , struct block , int);
c906108c SS	391
	392	/* The innermost context required by the stack and register variables
	393	we've encountered so far. To use this, set it to NULL, then call
	394	parse_<whatever>, then look at it. */
	395	extern struct block *innermost_block;
	396
	397	/* From eval.c */
	398
389e51db	399	/* Values of NOSIDE argument to eval_subexp. */
c906108c SS	400
c906108c SS	401	enum noside
c5aa993b JM	402	{
	403	EVAL_NORMAL,
	404	EVAL_SKIP, /* Only effect is to increment pos. */
	405	EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or
c906108c SS	406	call any functions. The value
	407	returned will have the correct
	408	type, and will have an
	409	approximately correct lvalue
	410	type (inaccuracy: anything that is
	411	listed as being in a register in
	412	the function in which it was
	413	declared will be lval_register). */
c5aa993b	414	};
c906108c	415
c5aa993b	416	extern struct value *evaluate_subexp_standard
a14ed312	417	(struct type , struct expression , int *, enum noside);
c906108c SS	418
	419	/* From expprint.c */
	420
d9fcf2fb	421	extern void print_expression (struct expression , struct ui_file );
c906108c	422
a14ed312	423	extern char *op_string (enum exp_opcode);
c906108c	424
24daaebc PH	425	extern void dump_raw_expression (struct expression , struct ui_file , char *);
24daaebc PH	426	extern void dump_prefix_expression (struct expression , struct ui_file );
c906108c	427
c5aa993b	428	#endif /* !defined (EXPRESSION_H) */