[binutils.git] / gdb / expression.h

/* Definitions for expressions stored in reversed prefix form, for GDB.
   Copyright 1986, 1989, 1992, 1994, 2000 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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#if !defined (EXPRESSION_H)
#define EXPRESSION_H 1


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


/* 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 Chill and Pascal. */
    BINOP_IN,			/* Returns 1 iff ARG1 IN ARG2. */

    /* This is the "colon operator" used various places in 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.  Chill syntax:  OP1(OP2:OP3).
       Return elements OP2 through OP3 of OP1.  */
    TERNOP_SLICE,

    /* A sub-string/sub-array.  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 an integer in the next exp_element.
       This is the number of a register to fetch (as an int).
       With another OP_REGISTER at the end, this makes three exp_elements.  */
    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,

    /* 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 dismabiguated 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_... 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,

    /* 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,

    /* 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 Chill).
       The gcc C syntax is NAME:VALUE or .NAME=VALUE, the Chill syntax is
       .NAME:VALUE.  Multiple labels (as in the Chill syntax
       .NAME1,.NAME2:VALUE) is represented as if it were
       .NAME1:(.NAME2:VALUE) (though that is not valid 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 unparsed expression.  Used for Scheme (for now at least) */
    OP_EXPRSTRING
  };

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 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_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_prefix_expression (struct expression *,
				    struct ui_file *,
				    char *);
extern void dump_postfix_expression (struct expression *,
				     struct ui_file *,
				     char *);

#endif /* !defined (EXPRESSION_H) */
Commit	Line	Data
c906108c	1	/* Definitions for expressions stored in reversed prefix form, for GDB.
d9fcf2fb	2	Copyright 1986, 1989, 1992, 1994, 2000 Free Software Foundation, Inc.
c906108c	3
c5aa993b	4	This file is part of GDB.
c906108c	5
c5aa993b JM	6	This program is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2 of the License, or
	9	(at your option) any later version.
c906108c	10
c5aa993b JM	11	This program is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
c906108c	15
c5aa993b JM	16	You should have received a copy of the GNU General Public License
	17	along with this program; if not, write to the Free Software
	18	Foundation, Inc., 59 Temple Place - Suite 330,
	19	Boston, MA 02111-1307, USA. */
c906108c SS	20
	21	#if !defined (EXPRESSION_H)
	22	#define EXPRESSION_H 1
	23
	24
c5aa993b	25	#include "symtab.h" /* Needed for "struct block" type. */
c906108c SS	26
	27
	28	/* Definitions for saved C expressions. */
	29
	30	/* An expression is represented as a vector of union exp_element's.
	31	Each exp_element is an opcode, except that some opcodes cause
	32	the following exp_element to be treated as a long or double constant
	33	or as a variable. The opcodes are obeyed, using a stack for temporaries.
	34	The value is left on the temporary stack at the end. */
	35
	36	/* When it is necessary to include a string,
	37	it can occupy as many exp_elements as it needs.
	38	We find the length of the string using strlen,
	39	divide to find out how many exp_elements are used up,
	40	and skip that many. Strings, like numbers, are indicated
	41	by the preceding opcode. */
	42
	43	enum exp_opcode
c5aa993b JM	44	{
	45	/* Used when it's necessary to pass an opcode which will be ignored,
	46	or to catch uninitialized values. */
	47	OP_NULL,
c906108c SS	48
	49	/* BINOP_... operate on two values computed by following subexpressions,
	50	replacing them by one result value. They take no immediate arguments. */
	51
c5aa993b JM	52	BINOP_ADD, /* + */
	53	BINOP_SUB, /* - */
	54	BINOP_MUL, /* * */
	55	BINOP_DIV, /* / */
	56	BINOP_REM, /* % */
	57	BINOP_MOD, /* mod (Knuth 1.2.4) */
	58	BINOP_LSH, /* << */
	59	BINOP_RSH, /* >> */
	60	BINOP_LOGICAL_AND, /* && */
	61	BINOP_LOGICAL_OR, /* \|\| */
	62	BINOP_BITWISE_AND, /* & */
	63	BINOP_BITWISE_IOR, /* \| */
	64	BINOP_BITWISE_XOR, /* ^ */
	65	BINOP_EQUAL, /* == */
	66	BINOP_NOTEQUAL, /* != */
	67	BINOP_LESS, /* < */
	68	BINOP_GTR, /* > */
	69	BINOP_LEQ, /* <= */
	70	BINOP_GEQ, /* >= */
	71	BINOP_REPEAT, /* @ */
	72	BINOP_ASSIGN, /* = */
	73	BINOP_COMMA, /* , */
	74	BINOP_SUBSCRIPT, /* x[y] */
	75	BINOP_EXP, /* Exponentiation */
	76
	77	/* C++. */
	78
	79	BINOP_MIN, /* <? */
	80	BINOP_MAX, /* >? */
c5aa993b JM	81
	82	/* STRUCTOP_MEMBER is used for pointer-to-member constructs.
	83	X . * Y translates into X STRUCTOP_MEMBER Y. */
	84	STRUCTOP_MEMBER,
	85
	86	/* STRUCTOP_MPTR is used for pointer-to-member constructs
	87	when X is a pointer instead of an aggregate. */
	88	STRUCTOP_MPTR,
	89
	90	/* end of C++. */
	91
	92	/* For Modula-2 integer division DIV */
	93	BINOP_INTDIV,
	94
	95	BINOP_ASSIGN_MODIFY, /* +=, -=, *=, and so on.
	96	The following exp_element is another opcode,
	97	a BINOP_, saying how to modify.
	98	Then comes another BINOP_ASSIGN_MODIFY,
	99	making three exp_elements in total. */
	100
	101	/* Modula-2 standard (binary) procedures */
	102	BINOP_VAL,
	103	BINOP_INCL,
	104	BINOP_EXCL,
	105
	106	/* Concatenate two operands, such as character strings or bitstrings.
	107	If the first operand is a integer expression, then it means concatenate
	108	the second operand with itself that many times. */
	109	BINOP_CONCAT,
	110
	111	/* For Chill and Pascal. */
	112	BINOP_IN, /* Returns 1 iff ARG1 IN ARG2. */
	113
	114	/* This is the "colon operator" used various places in Chill. */
	115	BINOP_RANGE,
	116
	117	/* This must be the highest BINOP_ value, for expprint.c. */
	118	BINOP_END,
	119
	120	/* Operates on three values computed by following subexpressions. */
	121	TERNOP_COND, /* ?: */
	122
	123	/* A sub-string/sub-array. Chill syntax: OP1(OP2:OP3).
	124	Return elements OP2 through OP3 of OP1. */
	125	TERNOP_SLICE,
	126
	127	/* A sub-string/sub-array. Chill syntax: OP1(OP2 UP OP3).
	128	Return OP3 elements of OP1, starting with element OP2. */
	129	TERNOP_SLICE_COUNT,
	130
	131	/* Multidimensional subscript operator, such as Modula-2 x[a,b,...].
	132	The dimensionality is encoded in the operator, like the number of
	133	function arguments in OP_FUNCALL, I.E. <OP><dimension><OP>.
	134	The value of the first following subexpression is subscripted
	135	by each of the next following subexpressions, one per dimension. */
	136	MULTI_SUBSCRIPT,
	137
	138	/* The OP_... series take immediate following arguments.
	139	After the arguments come another OP_... (the same one)
	140	so that the grouping can be recognized from the end. */
	141
	142	/* OP_LONG is followed by a type pointer in the next exp_element
	143	and the long constant value in the following exp_element.
	144	Then comes another OP_LONG.
145	Thus, the operation occupies four exp_elements. */
146	OP_LONG,
147
148	/* OP_DOUBLE is similar but takes a DOUBLEST constant instead of a long. */
149	OP_DOUBLE,
150
151	/* OP_VAR_VALUE takes one struct block * in the following element,
152	and one struct symbol * in the following exp_element, followed by
153	another OP_VAR_VALUE, making four exp_elements. If the block is
154	non-NULL, evaluate the symbol relative to the innermost frame
155	executing in that block; if the block is NULL use the selected frame. */
156	OP_VAR_VALUE,
157
158	/* OP_LAST is followed by an integer in the next exp_element.
159	The integer is zero for the last value printed,
160	or it is the absolute number of a history element.
161	With another OP_LAST at the end, this makes three exp_elements. */
162	OP_LAST,
163
164	/* OP_REGISTER is followed by an integer in the next exp_element.
165	This is the number of a register to fetch (as an int).
166	With another OP_REGISTER at the end, this makes three exp_elements. */
167	OP_REGISTER,
168
169	/* OP_INTERNALVAR is followed by an internalvar ptr in the next exp_element.
170	With another OP_INTERNALVAR at the end, this makes three exp_elements. */
171	OP_INTERNALVAR,
172
173	/* OP_FUNCALL is followed by an integer in the next exp_element.
174	The integer is the number of args to the function call.
175	That many plus one values from following subexpressions
176	are used, the first one being the function.
177	The integer is followed by a repeat of OP_FUNCALL,
178	making three exp_elements. */
179	OP_FUNCALL,
180
181	/* This is EXACTLY like OP_FUNCALL but is semantically different.
182	In F77, array subscript expressions, substring expressions
183	and function calls are all exactly the same syntactically. They may
184	only be dismabiguated at runtime. Thus this operator, which
185	indicates that we have found something of the form <name> ( <stuff> ) */
186	OP_F77_UNDETERMINED_ARGLIST,
187
188	/* The following OP is a special one, it introduces a F77 complex
189	literal. It is followed by exactly two args that are doubles. */
190	OP_COMPLEX,
191
192	/* OP_STRING represents a string constant.
193	Its format is the same as that of a STRUCTOP, but the string
194	data is just made into a string constant when the operation
195	is executed. */
196	OP_STRING,
197
198	/* OP_BITSTRING represents a packed bitstring constant.
199	Its format is the same as that of a STRUCTOP, but the bitstring
200	data is just made into a bitstring constant when the operation
201	is executed. */
202	OP_BITSTRING,
203
204	/* OP_ARRAY creates an array constant out of the following subexpressions.
205	It is followed by two exp_elements, the first containing an integer
206	that is the lower bound of the array and the second containing another
207	integer that is the upper bound of the array. The second integer is
208	followed by a repeat of OP_ARRAY, making four exp_elements total.
209	The bounds are used to compute the number of following subexpressions
210	to consume, as well as setting the bounds in the created array constant.
211	The type of the elements is taken from the type of the first subexp,
212	and they must all match. */
213	OP_ARRAY,
214
215	/* UNOP_CAST is followed by a type pointer in the next exp_element.
216	With another UNOP_CAST at the end, this makes three exp_elements.
217	It casts the value of the following subexpression. */
218	UNOP_CAST,
219
220	/* UNOP_MEMVAL is followed by a type pointer in the next exp_element
221	With another UNOP_MEMVAL at the end, this makes three exp_elements.
222	It casts the contents of the word addressed by the value of the
223	following subexpression. */
224	UNOP_MEMVAL,
225
226	/* UNOP_... operate on one value from a following subexpression
227	and replace it with a result. They take no immediate arguments. */
228
229	UNOP_NEG, /* Unary - */
230	UNOP_LOGICAL_NOT, /* Unary ! */
231	UNOP_COMPLEMENT, /* Unary ~ */
232	UNOP_IND, /* Unary * */
233	UNOP_ADDR, /* Unary & */
234	UNOP_PREINCREMENT, /* ++ before an expression */
235	UNOP_POSTINCREMENT, /* ++ after an expression */
236	UNOP_PREDECREMENT, /* -- before an expression */
237	UNOP_POSTDECREMENT, /* -- after an expression */
238	UNOP_SIZEOF, /* Unary sizeof (followed by expression) */
239
240	UNOP_PLUS, /* Unary plus */
241
242	UNOP_CAP, /* Modula-2 standard (unary) procedures */
243	UNOP_CHR,
244	UNOP_ORD,
245	UNOP_ABS,
246	UNOP_FLOAT,
247	UNOP_HIGH,
248	UNOP_MAX,
249	UNOP_MIN,
250	UNOP_ODD,
251	UNOP_TRUNC,
252
253	/* Chill builtin functions. */
254	UNOP_LOWER, UNOP_UPPER, UNOP_LENGTH, UNOP_CARD, UNOP_CHMAX, UNOP_CHMIN,
255
256	OP_BOOL, /* Modula-2 builtin BOOLEAN type */
257	OP_M2_STRING, /* Modula-2 string constants */
258
259	/* STRUCTOP_... operate on a value from a following subexpression
260	by extracting a structure component specified by a string
261	that appears in the following exp_elements (as many as needed).
262	STRUCTOP_STRUCT is used for "." and STRUCTOP_PTR for "->".
263	They differ only in the error message given in case the value is
264	not suitable or the structure component specified is not found.
265
266	The length of the string follows the opcode, followed by
267	BYTES_TO_EXP_ELEM(length) elements containing the data of the
268	string, followed by the length again and the opcode again. */
269
270	STRUCTOP_STRUCT,
271	STRUCTOP_PTR,
272
273	/* C++ */
274	/* OP_THIS is just a placeholder for the class instance variable.
275	It just comes in a tight (OP_THIS, OP_THIS) pair. */
276	OP_THIS,
277
278	/* OP_SCOPE surrounds a type name and a field name. The type
279	name is encoded as one element, but the field name stays as
280	a string, which, of course, is variable length. */
281	OP_SCOPE,
282
283	/* Used to represent named structure field values in brace initializers
284	(or tuples as they are called in Chill).
285	The gcc C syntax is NAME:VALUE or .NAME=VALUE, the Chill syntax is
286	.NAME:VALUE. Multiple labels (as in the Chill syntax
287	.NAME1,.NAME2:VALUE) is represented as if it were
288	.NAME1:(.NAME2:VALUE) (though that is not valid Chill syntax).
289
290	The NAME is represented as for STRUCTOP_STRUCT; VALUE follows. */
291	OP_LABELED,
292
293	/* OP_TYPE is for parsing types, and used with the "ptype" command
294	so we can look up types that are qualified by scope, either with
295	the GDB "::" operator, or the Modula-2 '.' operator. */
296	OP_TYPE,
297
298	/* An un-looked-up identifier. */
299	OP_NAME,
300
301	/* An unparsed expression. Used for Scheme (for now at least) */
302	OP_EXPRSTRING
303	};
c906108c SS	304
c906108c SS	305	union exp_element
c5aa993b JM	306	{
	307	enum exp_opcode opcode;
	308	struct symbol *symbol;
	309	LONGEST longconst;
	310	DOUBLEST doubleconst;
	311	/* Really sizeof (union exp_element) characters (or less for the last
	312	element of a string). */
	313	char string;
	314	struct type *type;
	315	struct internalvar *internalvar;
	316	struct block *block;
	317	};
c906108c SS	318
c906108c SS	319	struct expression
c5aa993b JM	320	{
	321	const struct language_defn language_defn; / language it was entered in */
	322	int nelts;
	323	union exp_element elts[1];
	324	};
c906108c SS	325
	326	/* Macros for converting between number of expression elements and bytes
	327	to store that many expression elements. */
	328
	329	#define EXP_ELEM_TO_BYTES(elements) \
	330	((elements) * sizeof (union exp_element))
	331	#define BYTES_TO_EXP_ELEM(bytes) \
	332	(((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element))
	333
	334	/* From parse.c */
	335
a14ed312	336	extern struct expression parse_expression (char );
c906108c	337
a14ed312	338	extern struct expression parse_exp_1 (char , struct block , int);
c906108c SS	339
	340	/* The innermost context required by the stack and register variables
	341	we've encountered so far. To use this, set it to NULL, then call
	342	parse_<whatever>, then look at it. */
	343	extern struct block *innermost_block;
	344
	345	/* From eval.c */
	346
	347	/* Values of NOSIDE argument to eval_subexp. */
	348
	349	enum noside
c5aa993b JM	350	{
	351	EVAL_NORMAL,
	352	EVAL_SKIP, /* Only effect is to increment pos. */
	353	EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or
c906108c SS	354	call any functions. The value
	355	returned will have the correct
	356	type, and will have an
	357	approximately correct lvalue
	358	type (inaccuracy: anything that is
	359	listed as being in a register in
	360	the function in which it was
	361	declared will be lval_register). */
c5aa993b	362	};
c906108c	363
c5aa993b	364	extern struct value *evaluate_subexp_standard
a14ed312	365	(struct type , struct expression , int *, enum noside);
c906108c SS	366
	367	/* From expprint.c */
	368
d9fcf2fb	369	extern void print_expression (struct expression , struct ui_file );
c906108c	370
a14ed312	371	extern char *op_string (enum exp_opcode);
c906108c	372
d9fcf2fb JM	373	extern void dump_prefix_expression (struct expression *,
	374	struct ui_file *,
	375	char *);
	376	extern void dump_postfix_expression (struct expression *,
	377	struct ui_file *,
	378	char *);
c906108c	379
c5aa993b	380	#endif /* !defined (EXPRESSION_H) */