1320 lines
34 KiB
C
1320 lines
34 KiB
C
/* Parse expressions for GDB.
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Copyright (C) 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
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1998, 1999, 2000, 2001, 2004, 2005, 2007, 2008, 2009
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Free Software Foundation, Inc.
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Modified from expread.y by the Department of Computer Science at the
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State University of New York at Buffalo, 1991.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Parse an expression from text in a string,
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and return the result as a struct expression pointer.
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That structure contains arithmetic operations in reverse polish,
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with constants represented by operations that are followed by special data.
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See expression.h for the details of the format.
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What is important here is that it can be built up sequentially
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during the process of parsing; the lower levels of the tree always
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come first in the result. */
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#include <ctype.h>
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#include "defs.h"
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#include "gdb_string.h"
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#include "symtab.h"
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#include "gdbtypes.h"
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#include "frame.h"
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#include "expression.h"
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#include "value.h"
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#include "command.h"
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#include "language.h"
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#include "f-lang.h"
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#include "parser-defs.h"
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#include "gdbcmd.h"
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#include "symfile.h" /* for overlay functions */
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#include "inferior.h"
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#include "doublest.h"
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#include "gdb_assert.h"
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#include "block.h"
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#include "source.h"
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#include "objfiles.h"
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#include "exceptions.h"
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#include "user-regs.h"
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/* Standard set of definitions for printing, dumping, prefixifying,
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* and evaluating expressions. */
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const struct exp_descriptor exp_descriptor_standard =
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{
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print_subexp_standard,
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operator_length_standard,
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op_name_standard,
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dump_subexp_body_standard,
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evaluate_subexp_standard
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};
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/* Global variables declared in parser-defs.h (and commented there). */
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struct expression *expout;
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int expout_size;
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int expout_ptr;
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struct block *expression_context_block;
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CORE_ADDR expression_context_pc;
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struct block *innermost_block;
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int arglist_len;
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union type_stack_elt *type_stack;
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int type_stack_depth, type_stack_size;
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char *lexptr;
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char *prev_lexptr;
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int paren_depth;
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int comma_terminates;
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/* True if parsing an expression to find a field reference. This is
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only used by completion. */
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int in_parse_field;
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/* The index of the last struct expression directly before a '.' or
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'->'. This is set when parsing and is only used when completing a
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field name. It is -1 if no dereference operation was found. */
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static int expout_last_struct = -1;
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/* A temporary buffer for identifiers, so we can null-terminate them.
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We allocate this with xrealloc. parse_exp_1 used to allocate with
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alloca, using the size of the whole expression as a conservative
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estimate of the space needed. However, macro expansion can
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introduce names longer than the original expression; there's no
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practical way to know beforehand how large that might be. */
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char *namecopy;
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size_t namecopy_size;
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static int expressiondebug = 0;
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static void
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show_expressiondebug (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file, _("Expression debugging is %s.\n"), value);
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}
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static void free_funcalls (void *ignore);
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static int prefixify_expression (struct expression *);
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static int prefixify_subexp (struct expression *, struct expression *, int,
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int);
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static struct expression *parse_exp_in_context (char **, struct block *, int,
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int, int *);
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void _initialize_parse (void);
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/* Data structure for saving values of arglist_len for function calls whose
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arguments contain other function calls. */
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struct funcall
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{
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struct funcall *next;
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int arglist_len;
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};
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static struct funcall *funcall_chain;
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/* Begin counting arguments for a function call,
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saving the data about any containing call. */
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void
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start_arglist (void)
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{
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struct funcall *new;
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new = (struct funcall *) xmalloc (sizeof (struct funcall));
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new->next = funcall_chain;
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new->arglist_len = arglist_len;
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arglist_len = 0;
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funcall_chain = new;
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}
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/* Return the number of arguments in a function call just terminated,
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and restore the data for the containing function call. */
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int
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end_arglist (void)
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{
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int val = arglist_len;
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struct funcall *call = funcall_chain;
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funcall_chain = call->next;
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arglist_len = call->arglist_len;
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xfree (call);
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return val;
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}
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/* Free everything in the funcall chain.
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Used when there is an error inside parsing. */
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static void
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free_funcalls (void *ignore)
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{
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struct funcall *call, *next;
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for (call = funcall_chain; call; call = next)
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{
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next = call->next;
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xfree (call);
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}
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}
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/* This page contains the functions for adding data to the struct expression
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being constructed. */
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/* Add one element to the end of the expression. */
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/* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
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a register through here */
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void
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write_exp_elt (union exp_element expelt)
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{
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if (expout_ptr >= expout_size)
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{
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expout_size *= 2;
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expout = (struct expression *)
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xrealloc ((char *) expout, sizeof (struct expression)
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+ EXP_ELEM_TO_BYTES (expout_size));
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}
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expout->elts[expout_ptr++] = expelt;
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}
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void
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write_exp_elt_opcode (enum exp_opcode expelt)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.opcode = expelt;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_sym (struct symbol *expelt)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.symbol = expelt;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_block (struct block *b)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.block = b;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_objfile (struct objfile *objfile)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.objfile = objfile;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_longcst (LONGEST expelt)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.longconst = expelt;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_dblcst (DOUBLEST expelt)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.doubleconst = expelt;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_decfloatcst (gdb_byte expelt[16])
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{
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union exp_element tmp;
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int index;
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for (index = 0; index < 16; index++)
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tmp.decfloatconst[index] = expelt[index];
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_type (struct type *expelt)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.type = expelt;
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write_exp_elt (tmp);
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}
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void
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write_exp_elt_intern (struct internalvar *expelt)
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{
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union exp_element tmp;
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memset (&tmp, 0, sizeof (union exp_element));
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tmp.internalvar = expelt;
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write_exp_elt (tmp);
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}
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/* Add a string constant to the end of the expression.
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String constants are stored by first writing an expression element
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that contains the length of the string, then stuffing the string
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constant itself into however many expression elements are needed
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to hold it, and then writing another expression element that contains
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the length of the string. I.E. an expression element at each end of
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the string records the string length, so you can skip over the
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expression elements containing the actual string bytes from either
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end of the string. Note that this also allows gdb to handle
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strings with embedded null bytes, as is required for some languages.
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Don't be fooled by the fact that the string is null byte terminated,
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this is strictly for the convenience of debugging gdb itself. Gdb
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Gdb does not depend up the string being null terminated, since the
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actual length is recorded in expression elements at each end of the
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string. The null byte is taken into consideration when computing how
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many expression elements are required to hold the string constant, of
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course. */
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void
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write_exp_string (struct stoken str)
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{
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int len = str.length;
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int lenelt;
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char *strdata;
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/* Compute the number of expression elements required to hold the string
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(including a null byte terminator), along with one expression element
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at each end to record the actual string length (not including the
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null byte terminator). */
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lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
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/* Ensure that we have enough available expression elements to store
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everything. */
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if ((expout_ptr + lenelt) >= expout_size)
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{
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expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
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expout = (struct expression *)
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xrealloc ((char *) expout, (sizeof (struct expression)
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+ EXP_ELEM_TO_BYTES (expout_size)));
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}
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/* Write the leading length expression element (which advances the current
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expression element index), then write the string constant followed by a
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terminating null byte, and then write the trailing length expression
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element. */
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write_exp_elt_longcst ((LONGEST) len);
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strdata = (char *) &expout->elts[expout_ptr];
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memcpy (strdata, str.ptr, len);
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*(strdata + len) = '\0';
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expout_ptr += lenelt - 2;
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write_exp_elt_longcst ((LONGEST) len);
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}
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||
|
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/* Add a bitstring constant to the end of the expression.
|
||
|
||
Bitstring constants are stored by first writing an expression element
|
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that contains the length of the bitstring (in bits), then stuffing the
|
||
bitstring constant itself into however many expression elements are
|
||
needed to hold it, and then writing another expression element that
|
||
contains the length of the bitstring. I.E. an expression element at
|
||
each end of the bitstring records the bitstring length, so you can skip
|
||
over the expression elements containing the actual bitstring bytes from
|
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either end of the bitstring. */
|
||
|
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void
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write_exp_bitstring (struct stoken str)
|
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{
|
||
int bits = str.length; /* length in bits */
|
||
int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
|
||
int lenelt;
|
||
char *strdata;
|
||
|
||
/* Compute the number of expression elements required to hold the bitstring,
|
||
along with one expression element at each end to record the actual
|
||
bitstring length in bits. */
|
||
|
||
lenelt = 2 + BYTES_TO_EXP_ELEM (len);
|
||
|
||
/* Ensure that we have enough available expression elements to store
|
||
everything. */
|
||
|
||
if ((expout_ptr + lenelt) >= expout_size)
|
||
{
|
||
expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
|
||
expout = (struct expression *)
|
||
xrealloc ((char *) expout, (sizeof (struct expression)
|
||
+ EXP_ELEM_TO_BYTES (expout_size)));
|
||
}
|
||
|
||
/* Write the leading length expression element (which advances the current
|
||
expression element index), then write the bitstring constant, and then
|
||
write the trailing length expression element. */
|
||
|
||
write_exp_elt_longcst ((LONGEST) bits);
|
||
strdata = (char *) &expout->elts[expout_ptr];
|
||
memcpy (strdata, str.ptr, len);
|
||
expout_ptr += lenelt - 2;
|
||
write_exp_elt_longcst ((LONGEST) bits);
|
||
}
|
||
|
||
/* Add the appropriate elements for a minimal symbol to the end of
|
||
the expression. */
|
||
|
||
void
|
||
write_exp_msymbol (struct minimal_symbol *msymbol)
|
||
{
|
||
struct objfile *objfile = msymbol_objfile (msymbol);
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
|
||
CORE_ADDR addr = SYMBOL_VALUE_ADDRESS (msymbol);
|
||
struct obj_section *section = SYMBOL_OBJ_SECTION (msymbol);
|
||
enum minimal_symbol_type type = MSYMBOL_TYPE (msymbol);
|
||
CORE_ADDR pc;
|
||
|
||
/* The minimal symbol might point to a function descriptor;
|
||
resolve it to the actual code address instead. */
|
||
pc = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, ¤t_target);
|
||
if (pc != addr)
|
||
{
|
||
/* In this case, assume we have a code symbol instead of
|
||
a data symbol. */
|
||
type = mst_text;
|
||
section = NULL;
|
||
addr = pc;
|
||
}
|
||
|
||
if (overlay_debugging)
|
||
addr = symbol_overlayed_address (addr, section);
|
||
|
||
write_exp_elt_opcode (OP_LONG);
|
||
/* Let's make the type big enough to hold a 64-bit address. */
|
||
write_exp_elt_type (builtin_type (gdbarch)->builtin_core_addr);
|
||
write_exp_elt_longcst ((LONGEST) addr);
|
||
write_exp_elt_opcode (OP_LONG);
|
||
|
||
if (section && section->the_bfd_section->flags & SEC_THREAD_LOCAL)
|
||
{
|
||
write_exp_elt_opcode (UNOP_MEMVAL_TLS);
|
||
write_exp_elt_objfile (objfile);
|
||
write_exp_elt_type (builtin_type (gdbarch)->nodebug_tls_symbol);
|
||
write_exp_elt_opcode (UNOP_MEMVAL_TLS);
|
||
return;
|
||
}
|
||
|
||
write_exp_elt_opcode (UNOP_MEMVAL);
|
||
switch (type)
|
||
{
|
||
case mst_text:
|
||
case mst_file_text:
|
||
case mst_solib_trampoline:
|
||
write_exp_elt_type (builtin_type (gdbarch)->nodebug_text_symbol);
|
||
break;
|
||
|
||
case mst_data:
|
||
case mst_file_data:
|
||
case mst_bss:
|
||
case mst_file_bss:
|
||
write_exp_elt_type (builtin_type (gdbarch)->nodebug_data_symbol);
|
||
break;
|
||
|
||
default:
|
||
write_exp_elt_type (builtin_type (gdbarch)->nodebug_unknown_symbol);
|
||
break;
|
||
}
|
||
write_exp_elt_opcode (UNOP_MEMVAL);
|
||
}
|
||
|
||
/* Mark the current index as the starting location of a structure
|
||
expression. This is used when completing on field names. */
|
||
|
||
void
|
||
mark_struct_expression (void)
|
||
{
|
||
expout_last_struct = expout_ptr;
|
||
}
|
||
|
||
|
||
/* Recognize tokens that start with '$'. These include:
|
||
|
||
$regname A native register name or a "standard
|
||
register name".
|
||
|
||
$variable A convenience variable with a name chosen
|
||
by the user.
|
||
|
||
$digits Value history with index <digits>, starting
|
||
from the first value which has index 1.
|
||
|
||
$$digits Value history with index <digits> relative
|
||
to the last value. I.E. $$0 is the last
|
||
value, $$1 is the one previous to that, $$2
|
||
is the one previous to $$1, etc.
|
||
|
||
$ | $0 | $$0 The last value in the value history.
|
||
|
||
$$ An abbreviation for the second to the last
|
||
value in the value history, I.E. $$1
|
||
|
||
*/
|
||
|
||
void
|
||
write_dollar_variable (struct stoken str)
|
||
{
|
||
struct symbol *sym = NULL;
|
||
struct minimal_symbol *msym = NULL;
|
||
struct internalvar *isym = NULL;
|
||
|
||
/* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
|
||
and $$digits (equivalent to $<-digits> if you could type that). */
|
||
|
||
int negate = 0;
|
||
int i = 1;
|
||
/* Double dollar means negate the number and add -1 as well.
|
||
Thus $$ alone means -1. */
|
||
if (str.length >= 2 && str.ptr[1] == '$')
|
||
{
|
||
negate = 1;
|
||
i = 2;
|
||
}
|
||
if (i == str.length)
|
||
{
|
||
/* Just dollars (one or two) */
|
||
i = -negate;
|
||
goto handle_last;
|
||
}
|
||
/* Is the rest of the token digits? */
|
||
for (; i < str.length; i++)
|
||
if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
|
||
break;
|
||
if (i == str.length)
|
||
{
|
||
i = atoi (str.ptr + 1 + negate);
|
||
if (negate)
|
||
i = -i;
|
||
goto handle_last;
|
||
}
|
||
|
||
/* Handle tokens that refer to machine registers:
|
||
$ followed by a register name. */
|
||
i = user_reg_map_name_to_regnum (current_gdbarch,
|
||
str.ptr + 1, str.length - 1);
|
||
if (i >= 0)
|
||
goto handle_register;
|
||
|
||
/* Any names starting with $ are probably debugger internal variables. */
|
||
|
||
isym = lookup_only_internalvar (copy_name (str) + 1);
|
||
if (isym)
|
||
{
|
||
write_exp_elt_opcode (OP_INTERNALVAR);
|
||
write_exp_elt_intern (isym);
|
||
write_exp_elt_opcode (OP_INTERNALVAR);
|
||
return;
|
||
}
|
||
|
||
/* On some systems, such as HP-UX and hppa-linux, certain system routines
|
||
have names beginning with $ or $$. Check for those, first. */
|
||
|
||
sym = lookup_symbol (copy_name (str), (struct block *) NULL,
|
||
VAR_DOMAIN, (int *) NULL);
|
||
if (sym)
|
||
{
|
||
write_exp_elt_opcode (OP_VAR_VALUE);
|
||
write_exp_elt_block (block_found); /* set by lookup_symbol */
|
||
write_exp_elt_sym (sym);
|
||
write_exp_elt_opcode (OP_VAR_VALUE);
|
||
return;
|
||
}
|
||
msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);
|
||
if (msym)
|
||
{
|
||
write_exp_msymbol (msym);
|
||
return;
|
||
}
|
||
|
||
/* Any other names are assumed to be debugger internal variables. */
|
||
|
||
write_exp_elt_opcode (OP_INTERNALVAR);
|
||
write_exp_elt_intern (create_internalvar (copy_name (str) + 1));
|
||
write_exp_elt_opcode (OP_INTERNALVAR);
|
||
return;
|
||
handle_last:
|
||
write_exp_elt_opcode (OP_LAST);
|
||
write_exp_elt_longcst ((LONGEST) i);
|
||
write_exp_elt_opcode (OP_LAST);
|
||
return;
|
||
handle_register:
|
||
write_exp_elt_opcode (OP_REGISTER);
|
||
str.length--;
|
||
str.ptr++;
|
||
write_exp_string (str);
|
||
write_exp_elt_opcode (OP_REGISTER);
|
||
return;
|
||
}
|
||
|
||
|
||
char *
|
||
find_template_name_end (char *p)
|
||
{
|
||
int depth = 1;
|
||
int just_seen_right = 0;
|
||
int just_seen_colon = 0;
|
||
int just_seen_space = 0;
|
||
|
||
if (!p || (*p != '<'))
|
||
return 0;
|
||
|
||
while (*++p)
|
||
{
|
||
switch (*p)
|
||
{
|
||
case '\'':
|
||
case '\"':
|
||
case '{':
|
||
case '}':
|
||
/* In future, may want to allow these?? */
|
||
return 0;
|
||
case '<':
|
||
depth++; /* start nested template */
|
||
if (just_seen_colon || just_seen_right || just_seen_space)
|
||
return 0; /* but not after : or :: or > or space */
|
||
break;
|
||
case '>':
|
||
if (just_seen_colon || just_seen_right)
|
||
return 0; /* end a (nested?) template */
|
||
just_seen_right = 1; /* but not after : or :: */
|
||
if (--depth == 0) /* also disallow >>, insist on > > */
|
||
return ++p; /* if outermost ended, return */
|
||
break;
|
||
case ':':
|
||
if (just_seen_space || (just_seen_colon > 1))
|
||
return 0; /* nested class spec coming up */
|
||
just_seen_colon++; /* we allow :: but not :::: */
|
||
break;
|
||
case ' ':
|
||
break;
|
||
default:
|
||
if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
|
||
(*p >= 'A' && *p <= 'Z') ||
|
||
(*p >= '0' && *p <= '9') ||
|
||
(*p == '_') || (*p == ',') || /* commas for template args */
|
||
(*p == '&') || (*p == '*') || /* pointer and ref types */
|
||
(*p == '(') || (*p == ')') || /* function types */
|
||
(*p == '[') || (*p == ']'))) /* array types */
|
||
return 0;
|
||
}
|
||
if (*p != ' ')
|
||
just_seen_space = 0;
|
||
if (*p != ':')
|
||
just_seen_colon = 0;
|
||
if (*p != '>')
|
||
just_seen_right = 0;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
|
||
|
||
/* Return a null-terminated temporary copy of the name
|
||
of a string token. */
|
||
|
||
char *
|
||
copy_name (struct stoken token)
|
||
{
|
||
/* Make sure there's enough space for the token. */
|
||
if (namecopy_size < token.length + 1)
|
||
{
|
||
namecopy_size = token.length + 1;
|
||
namecopy = xrealloc (namecopy, token.length + 1);
|
||
}
|
||
|
||
memcpy (namecopy, token.ptr, token.length);
|
||
namecopy[token.length] = 0;
|
||
|
||
return namecopy;
|
||
}
|
||
|
||
/* Reverse an expression from suffix form (in which it is constructed)
|
||
to prefix form (in which we can conveniently print or execute it).
|
||
Ordinarily this always returns -1. However, if EXPOUT_LAST_STRUCT
|
||
is not -1 (i.e., we are trying to complete a field name), it will
|
||
return the index of the subexpression which is the left-hand-side
|
||
of the struct operation at EXPOUT_LAST_STRUCT. */
|
||
|
||
static int
|
||
prefixify_expression (struct expression *expr)
|
||
{
|
||
int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
|
||
struct expression *temp;
|
||
int inpos = expr->nelts, outpos = 0;
|
||
|
||
temp = (struct expression *) alloca (len);
|
||
|
||
/* Copy the original expression into temp. */
|
||
memcpy (temp, expr, len);
|
||
|
||
return prefixify_subexp (temp, expr, inpos, outpos);
|
||
}
|
||
|
||
/* Return the number of exp_elements in the postfix subexpression
|
||
of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
|
||
|
||
int
|
||
length_of_subexp (struct expression *expr, int endpos)
|
||
{
|
||
int oplen, args, i;
|
||
|
||
operator_length (expr, endpos, &oplen, &args);
|
||
|
||
while (args > 0)
|
||
{
|
||
oplen += length_of_subexp (expr, endpos - oplen);
|
||
args--;
|
||
}
|
||
|
||
return oplen;
|
||
}
|
||
|
||
/* Sets *OPLENP to the length of the operator whose (last) index is
|
||
ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
|
||
operator takes. */
|
||
|
||
void
|
||
operator_length (struct expression *expr, int endpos, int *oplenp, int *argsp)
|
||
{
|
||
expr->language_defn->la_exp_desc->operator_length (expr, endpos,
|
||
oplenp, argsp);
|
||
}
|
||
|
||
/* Default value for operator_length in exp_descriptor vectors. */
|
||
|
||
void
|
||
operator_length_standard (struct expression *expr, int endpos,
|
||
int *oplenp, int *argsp)
|
||
{
|
||
int oplen = 1;
|
||
int args = 0;
|
||
enum f90_range_type range_type;
|
||
int i;
|
||
|
||
if (endpos < 1)
|
||
error (_("?error in operator_length_standard"));
|
||
|
||
i = (int) expr->elts[endpos - 1].opcode;
|
||
|
||
switch (i)
|
||
{
|
||
/* C++ */
|
||
case OP_SCOPE:
|
||
oplen = longest_to_int (expr->elts[endpos - 2].longconst);
|
||
oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
|
||
break;
|
||
|
||
case OP_LONG:
|
||
case OP_DOUBLE:
|
||
case OP_DECFLOAT:
|
||
case OP_VAR_VALUE:
|
||
oplen = 4;
|
||
break;
|
||
|
||
case OP_TYPE:
|
||
case OP_BOOL:
|
||
case OP_LAST:
|
||
case OP_INTERNALVAR:
|
||
oplen = 3;
|
||
break;
|
||
|
||
case OP_COMPLEX:
|
||
oplen = 3;
|
||
args = 2;
|
||
break;
|
||
|
||
case OP_FUNCALL:
|
||
case OP_F77_UNDETERMINED_ARGLIST:
|
||
oplen = 3;
|
||
args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
|
||
break;
|
||
|
||
case OP_OBJC_MSGCALL: /* Objective C message (method) call */
|
||
oplen = 4;
|
||
args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
|
||
break;
|
||
|
||
case UNOP_MAX:
|
||
case UNOP_MIN:
|
||
oplen = 3;
|
||
break;
|
||
|
||
case BINOP_VAL:
|
||
case UNOP_CAST:
|
||
case UNOP_MEMVAL:
|
||
oplen = 3;
|
||
args = 1;
|
||
break;
|
||
|
||
case UNOP_MEMVAL_TLS:
|
||
oplen = 4;
|
||
args = 1;
|
||
break;
|
||
|
||
case UNOP_ABS:
|
||
case UNOP_CAP:
|
||
case UNOP_CHR:
|
||
case UNOP_FLOAT:
|
||
case UNOP_HIGH:
|
||
case UNOP_ODD:
|
||
case UNOP_ORD:
|
||
case UNOP_TRUNC:
|
||
oplen = 1;
|
||
args = 1;
|
||
break;
|
||
|
||
case OP_LABELED:
|
||
case STRUCTOP_STRUCT:
|
||
case STRUCTOP_PTR:
|
||
args = 1;
|
||
/* fall through */
|
||
case OP_REGISTER:
|
||
case OP_M2_STRING:
|
||
case OP_STRING:
|
||
case OP_OBJC_NSSTRING: /* Objective C Foundation Class NSString constant */
|
||
case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op */
|
||
case OP_NAME:
|
||
oplen = longest_to_int (expr->elts[endpos - 2].longconst);
|
||
oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
|
||
break;
|
||
|
||
case OP_BITSTRING:
|
||
oplen = longest_to_int (expr->elts[endpos - 2].longconst);
|
||
oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
|
||
oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
|
||
break;
|
||
|
||
case OP_ARRAY:
|
||
oplen = 4;
|
||
args = longest_to_int (expr->elts[endpos - 2].longconst);
|
||
args -= longest_to_int (expr->elts[endpos - 3].longconst);
|
||
args += 1;
|
||
break;
|
||
|
||
case TERNOP_COND:
|
||
case TERNOP_SLICE:
|
||
case TERNOP_SLICE_COUNT:
|
||
args = 3;
|
||
break;
|
||
|
||
/* Modula-2 */
|
||
case MULTI_SUBSCRIPT:
|
||
oplen = 3;
|
||
args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
|
||
break;
|
||
|
||
case BINOP_ASSIGN_MODIFY:
|
||
oplen = 3;
|
||
args = 2;
|
||
break;
|
||
|
||
/* C++ */
|
||
case OP_THIS:
|
||
case OP_OBJC_SELF:
|
||
oplen = 2;
|
||
break;
|
||
|
||
case OP_F90_RANGE:
|
||
oplen = 3;
|
||
|
||
range_type = longest_to_int (expr->elts[endpos - 2].longconst);
|
||
switch (range_type)
|
||
{
|
||
case LOW_BOUND_DEFAULT:
|
||
case HIGH_BOUND_DEFAULT:
|
||
args = 1;
|
||
break;
|
||
case BOTH_BOUND_DEFAULT:
|
||
args = 0;
|
||
break;
|
||
case NONE_BOUND_DEFAULT:
|
||
args = 2;
|
||
break;
|
||
}
|
||
|
||
break;
|
||
|
||
default:
|
||
args = 1 + (i < (int) BINOP_END);
|
||
}
|
||
|
||
*oplenp = oplen;
|
||
*argsp = args;
|
||
}
|
||
|
||
/* Copy the subexpression ending just before index INEND in INEXPR
|
||
into OUTEXPR, starting at index OUTBEG.
|
||
In the process, convert it from suffix to prefix form.
|
||
If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
|
||
Otherwise, it returns the index of the subexpression which is the
|
||
left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
|
||
|
||
static int
|
||
prefixify_subexp (struct expression *inexpr,
|
||
struct expression *outexpr, int inend, int outbeg)
|
||
{
|
||
int oplen;
|
||
int args;
|
||
int i;
|
||
int *arglens;
|
||
enum exp_opcode opcode;
|
||
int result = -1;
|
||
|
||
operator_length (inexpr, inend, &oplen, &args);
|
||
|
||
/* Copy the final operator itself, from the end of the input
|
||
to the beginning of the output. */
|
||
inend -= oplen;
|
||
memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
|
||
EXP_ELEM_TO_BYTES (oplen));
|
||
outbeg += oplen;
|
||
|
||
if (expout_last_struct == inend)
|
||
result = outbeg - oplen;
|
||
|
||
/* Find the lengths of the arg subexpressions. */
|
||
arglens = (int *) alloca (args * sizeof (int));
|
||
for (i = args - 1; i >= 0; i--)
|
||
{
|
||
oplen = length_of_subexp (inexpr, inend);
|
||
arglens[i] = oplen;
|
||
inend -= oplen;
|
||
}
|
||
|
||
/* Now copy each subexpression, preserving the order of
|
||
the subexpressions, but prefixifying each one.
|
||
In this loop, inend starts at the beginning of
|
||
the expression this level is working on
|
||
and marches forward over the arguments.
|
||
outbeg does similarly in the output. */
|
||
for (i = 0; i < args; i++)
|
||
{
|
||
int r;
|
||
oplen = arglens[i];
|
||
inend += oplen;
|
||
r = prefixify_subexp (inexpr, outexpr, inend, outbeg);
|
||
if (r != -1)
|
||
{
|
||
/* Return immediately. We probably have only parsed a
|
||
partial expression, so we don't want to try to reverse
|
||
the other operands. */
|
||
return r;
|
||
}
|
||
outbeg += oplen;
|
||
}
|
||
|
||
return result;
|
||
}
|
||
|
||
/* This page contains the two entry points to this file. */
|
||
|
||
/* Read an expression from the string *STRINGPTR points to,
|
||
parse it, and return a pointer to a struct expression that we malloc.
|
||
Use block BLOCK as the lexical context for variable names;
|
||
if BLOCK is zero, use the block of the selected stack frame.
|
||
Meanwhile, advance *STRINGPTR to point after the expression,
|
||
at the first nonwhite character that is not part of the expression
|
||
(possibly a null character).
|
||
|
||
If COMMA is nonzero, stop if a comma is reached. */
|
||
|
||
struct expression *
|
||
parse_exp_1 (char **stringptr, struct block *block, int comma)
|
||
{
|
||
return parse_exp_in_context (stringptr, block, comma, 0, NULL);
|
||
}
|
||
|
||
/* As for parse_exp_1, except that if VOID_CONTEXT_P, then
|
||
no value is expected from the expression.
|
||
OUT_SUBEXP is set when attempting to complete a field name; in this
|
||
case it is set to the index of the subexpression on the
|
||
left-hand-side of the struct op. If not doing such completion, it
|
||
is left untouched. */
|
||
|
||
static struct expression *
|
||
parse_exp_in_context (char **stringptr, struct block *block, int comma,
|
||
int void_context_p, int *out_subexp)
|
||
{
|
||
volatile struct gdb_exception except;
|
||
struct cleanup *old_chain;
|
||
int subexp;
|
||
|
||
lexptr = *stringptr;
|
||
prev_lexptr = NULL;
|
||
|
||
paren_depth = 0;
|
||
type_stack_depth = 0;
|
||
expout_last_struct = -1;
|
||
|
||
comma_terminates = comma;
|
||
|
||
if (lexptr == 0 || *lexptr == 0)
|
||
error_no_arg (_("expression to compute"));
|
||
|
||
old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
|
||
funcall_chain = 0;
|
||
|
||
expression_context_block = block;
|
||
|
||
/* If no context specified, try using the current frame, if any. */
|
||
if (!expression_context_block)
|
||
expression_context_block = get_selected_block (&expression_context_pc);
|
||
else
|
||
expression_context_pc = BLOCK_START (expression_context_block);
|
||
|
||
/* Fall back to using the current source static context, if any. */
|
||
|
||
if (!expression_context_block)
|
||
{
|
||
struct symtab_and_line cursal = get_current_source_symtab_and_line ();
|
||
if (cursal.symtab)
|
||
expression_context_block
|
||
= BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal.symtab), STATIC_BLOCK);
|
||
if (expression_context_block)
|
||
expression_context_pc = BLOCK_START (expression_context_block);
|
||
}
|
||
|
||
expout_size = 10;
|
||
expout_ptr = 0;
|
||
expout = (struct expression *)
|
||
xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size));
|
||
expout->language_defn = current_language;
|
||
expout->gdbarch = current_gdbarch;
|
||
|
||
TRY_CATCH (except, RETURN_MASK_ALL)
|
||
{
|
||
if (current_language->la_parser ())
|
||
current_language->la_error (NULL);
|
||
}
|
||
if (except.reason < 0)
|
||
{
|
||
if (! in_parse_field)
|
||
{
|
||
xfree (expout);
|
||
throw_exception (except);
|
||
}
|
||
}
|
||
|
||
discard_cleanups (old_chain);
|
||
|
||
/* Record the actual number of expression elements, and then
|
||
reallocate the expression memory so that we free up any
|
||
excess elements. */
|
||
|
||
expout->nelts = expout_ptr;
|
||
expout = (struct expression *)
|
||
xrealloc ((char *) expout,
|
||
sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));;
|
||
|
||
/* Convert expression from postfix form as generated by yacc
|
||
parser, to a prefix form. */
|
||
|
||
if (expressiondebug)
|
||
dump_raw_expression (expout, gdb_stdlog,
|
||
"before conversion to prefix form");
|
||
|
||
subexp = prefixify_expression (expout);
|
||
if (out_subexp)
|
||
*out_subexp = subexp;
|
||
|
||
current_language->la_post_parser (&expout, void_context_p);
|
||
|
||
if (expressiondebug)
|
||
dump_prefix_expression (expout, gdb_stdlog);
|
||
|
||
*stringptr = lexptr;
|
||
return expout;
|
||
}
|
||
|
||
/* Parse STRING as an expression, and complain if this fails
|
||
to use up all of the contents of STRING. */
|
||
|
||
struct expression *
|
||
parse_expression (char *string)
|
||
{
|
||
struct expression *exp;
|
||
exp = parse_exp_1 (&string, 0, 0);
|
||
if (*string)
|
||
error (_("Junk after end of expression."));
|
||
return exp;
|
||
}
|
||
|
||
/* Parse STRING as an expression. If parsing ends in the middle of a
|
||
field reference, return the type of the left-hand-side of the
|
||
reference; furthermore, if the parsing ends in the field name,
|
||
return the field name in *NAME. In all other cases, return NULL.
|
||
Returned non-NULL *NAME must be freed by the caller. */
|
||
|
||
struct type *
|
||
parse_field_expression (char *string, char **name)
|
||
{
|
||
struct expression *exp = NULL;
|
||
struct value *val;
|
||
int subexp;
|
||
volatile struct gdb_exception except;
|
||
|
||
TRY_CATCH (except, RETURN_MASK_ALL)
|
||
{
|
||
in_parse_field = 1;
|
||
exp = parse_exp_in_context (&string, 0, 0, 0, &subexp);
|
||
}
|
||
in_parse_field = 0;
|
||
if (except.reason < 0 || ! exp)
|
||
return NULL;
|
||
if (expout_last_struct == -1)
|
||
{
|
||
xfree (exp);
|
||
return NULL;
|
||
}
|
||
|
||
*name = extract_field_op (exp, &subexp);
|
||
if (!*name)
|
||
{
|
||
xfree (exp);
|
||
return NULL;
|
||
}
|
||
/* (*NAME) is a part of the EXP memory block freed below. */
|
||
*name = xstrdup (*name);
|
||
|
||
val = evaluate_subexpression_type (exp, subexp);
|
||
xfree (exp);
|
||
|
||
return value_type (val);
|
||
}
|
||
|
||
/* A post-parser that does nothing */
|
||
|
||
void
|
||
null_post_parser (struct expression **exp, int void_context_p)
|
||
{
|
||
}
|
||
|
||
/* Stuff for maintaining a stack of types. Currently just used by C, but
|
||
probably useful for any language which declares its types "backwards". */
|
||
|
||
static void
|
||
check_type_stack_depth (void)
|
||
{
|
||
if (type_stack_depth == type_stack_size)
|
||
{
|
||
type_stack_size *= 2;
|
||
type_stack = (union type_stack_elt *)
|
||
xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack));
|
||
}
|
||
}
|
||
|
||
void
|
||
push_type (enum type_pieces tp)
|
||
{
|
||
check_type_stack_depth ();
|
||
type_stack[type_stack_depth++].piece = tp;
|
||
}
|
||
|
||
void
|
||
push_type_int (int n)
|
||
{
|
||
check_type_stack_depth ();
|
||
type_stack[type_stack_depth++].int_val = n;
|
||
}
|
||
|
||
void
|
||
push_type_address_space (char *string)
|
||
{
|
||
push_type_int (address_space_name_to_int (string));
|
||
}
|
||
|
||
enum type_pieces
|
||
pop_type (void)
|
||
{
|
||
if (type_stack_depth)
|
||
return type_stack[--type_stack_depth].piece;
|
||
return tp_end;
|
||
}
|
||
|
||
int
|
||
pop_type_int (void)
|
||
{
|
||
if (type_stack_depth)
|
||
return type_stack[--type_stack_depth].int_val;
|
||
/* "Can't happen". */
|
||
return 0;
|
||
}
|
||
|
||
/* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
|
||
as modified by all the stuff on the stack. */
|
||
struct type *
|
||
follow_types (struct type *follow_type)
|
||
{
|
||
int done = 0;
|
||
int make_const = 0;
|
||
int make_volatile = 0;
|
||
int make_addr_space = 0;
|
||
int array_size;
|
||
struct type *range_type;
|
||
|
||
while (!done)
|
||
switch (pop_type ())
|
||
{
|
||
case tp_end:
|
||
done = 1;
|
||
if (make_const)
|
||
follow_type = make_cv_type (make_const,
|
||
TYPE_VOLATILE (follow_type),
|
||
follow_type, 0);
|
||
if (make_volatile)
|
||
follow_type = make_cv_type (TYPE_CONST (follow_type),
|
||
make_volatile,
|
||
follow_type, 0);
|
||
if (make_addr_space)
|
||
follow_type = make_type_with_address_space (follow_type,
|
||
make_addr_space);
|
||
make_const = make_volatile = 0;
|
||
make_addr_space = 0;
|
||
break;
|
||
case tp_const:
|
||
make_const = 1;
|
||
break;
|
||
case tp_volatile:
|
||
make_volatile = 1;
|
||
break;
|
||
case tp_space_identifier:
|
||
make_addr_space = pop_type_int ();
|
||
break;
|
||
case tp_pointer:
|
||
follow_type = lookup_pointer_type (follow_type);
|
||
if (make_const)
|
||
follow_type = make_cv_type (make_const,
|
||
TYPE_VOLATILE (follow_type),
|
||
follow_type, 0);
|
||
if (make_volatile)
|
||
follow_type = make_cv_type (TYPE_CONST (follow_type),
|
||
make_volatile,
|
||
follow_type, 0);
|
||
if (make_addr_space)
|
||
follow_type = make_type_with_address_space (follow_type,
|
||
make_addr_space);
|
||
make_const = make_volatile = 0;
|
||
make_addr_space = 0;
|
||
break;
|
||
case tp_reference:
|
||
follow_type = lookup_reference_type (follow_type);
|
||
if (make_const)
|
||
follow_type = make_cv_type (make_const,
|
||
TYPE_VOLATILE (follow_type),
|
||
follow_type, 0);
|
||
if (make_volatile)
|
||
follow_type = make_cv_type (TYPE_CONST (follow_type),
|
||
make_volatile,
|
||
follow_type, 0);
|
||
if (make_addr_space)
|
||
follow_type = make_type_with_address_space (follow_type,
|
||
make_addr_space);
|
||
make_const = make_volatile = 0;
|
||
make_addr_space = 0;
|
||
break;
|
||
case tp_array:
|
||
array_size = pop_type_int ();
|
||
/* FIXME-type-allocation: need a way to free this type when we are
|
||
done with it. */
|
||
range_type =
|
||
create_range_type ((struct type *) NULL,
|
||
builtin_type_int32, 0,
|
||
array_size >= 0 ? array_size - 1 : 0);
|
||
follow_type =
|
||
create_array_type ((struct type *) NULL,
|
||
follow_type, range_type);
|
||
if (array_size < 0)
|
||
TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (follow_type) = 1;
|
||
break;
|
||
case tp_function:
|
||
/* FIXME-type-allocation: need a way to free this type when we are
|
||
done with it. */
|
||
follow_type = lookup_function_type (follow_type);
|
||
break;
|
||
}
|
||
return follow_type;
|
||
}
|
||
|
||
/* This function avoids direct calls to fprintf
|
||
in the parser generated debug code. */
|
||
void
|
||
parser_fprintf (FILE *x, const char *y, ...)
|
||
{
|
||
va_list args;
|
||
va_start (args, y);
|
||
if (x == stderr)
|
||
vfprintf_unfiltered (gdb_stderr, y, args);
|
||
else
|
||
{
|
||
fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n");
|
||
vfprintf_unfiltered (gdb_stderr, y, args);
|
||
}
|
||
va_end (args);
|
||
}
|
||
|
||
void
|
||
_initialize_parse (void)
|
||
{
|
||
type_stack_size = 80;
|
||
type_stack_depth = 0;
|
||
type_stack = (union type_stack_elt *)
|
||
xmalloc (type_stack_size * sizeof (*type_stack));
|
||
|
||
add_setshow_zinteger_cmd ("expression", class_maintenance,
|
||
&expressiondebug, _("\
|
||
Set expression debugging."), _("\
|
||
Show expression debugging."), _("\
|
||
When non-zero, the internal representation of expressions will be printed."),
|
||
NULL,
|
||
show_expressiondebug,
|
||
&setdebuglist, &showdebuglist);
|
||
}
|