379 lines
13 KiB
C
379 lines
13 KiB
C
/* Definitions for expressions stored in reversed prefix form, for GDB.
|
|
Copyright 1986, 1989, 1992, 1994 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
|
|
|
|
#if !defined (EXPRESSION_H)
|
|
#define EXPRESSION_H 1
|
|
|
|
#ifdef __STDC__
|
|
struct block; /* Forward declaration for prototypes */
|
|
#endif
|
|
|
|
/* 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, /* >? */
|
|
BINOP_SCOPE, /* :: */
|
|
|
|
/* 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 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 double 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,
|
|
|
|
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
|
|
};
|
|
|
|
union exp_element
|
|
{
|
|
enum exp_opcode opcode;
|
|
struct symbol *symbol;
|
|
LONGEST longconst;
|
|
double 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))
|
|
|
|
#include "value.h"
|
|
|
|
/* From parse.c */
|
|
|
|
extern struct expression *parse_expression PARAMS ((char *));
|
|
|
|
extern struct expression *parse_exp_1 PARAMS ((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
|
|
PARAMS ((struct type *, struct expression *, int*, enum noside));
|
|
|
|
extern value_ptr evaluate_subexp_with_coercion PARAMS ((struct expression *,
|
|
int *, enum noside));
|
|
|
|
/* From expprint.c */
|
|
|
|
extern void print_expression PARAMS ((struct expression *, GDB_FILE *));
|
|
|
|
extern char *op_string PARAMS ((enum exp_opcode));
|
|
|
|
/* To enable dumping of all parsed expressions in a human readable
|
|
form, define DEBUG_EXPRESSIONS. This is a compile time constant
|
|
at the moment, since it's not clear that this feature is important
|
|
enough to include by default. */
|
|
|
|
#ifdef DEBUG_EXPRESSIONS
|
|
extern void dump_expression PARAMS ((struct expression *, GDB_FILE *, char *));
|
|
#define DUMP_EXPRESSION(exp,file,note) dump_expression ((exp), (file), (note))
|
|
#else
|
|
#define DUMP_EXPRESSION(exp,file,note) /* Null expansion */
|
|
#endif /* DEBUG_EXPRESSIONS */
|
|
|
|
#endif /* !defined (EXPRESSION_H) */
|