1014 lines
25 KiB
C
1014 lines
25 KiB
C
/* Parse expressions for GDB.
|
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Copyright (C) 1986, 1989, 1990, 1991, 1994 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 2 of the License, or
|
||
(at your option) any later version.
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||
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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, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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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 "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 "parser-defs.h"
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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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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 *namecopy;
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int paren_depth;
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int comma_terminates;
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static void
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free_funcalls PARAMS ((void));
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static void
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prefixify_expression PARAMS ((struct expression *));
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static int
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length_of_subexp PARAMS ((struct expression *, int));
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static void
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prefixify_subexp PARAMS ((struct expression *, struct expression *, int, int));
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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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/* Assign machine-independent names to certain registers
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(unless overridden by the REGISTER_NAMES table) */
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#ifdef NO_STD_REGS
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unsigned num_std_regs = 0;
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struct std_regs std_regs[1];
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#else
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struct std_regs std_regs[] = {
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#ifdef PC_REGNUM
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{ "pc", PC_REGNUM },
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#endif
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#ifdef FP_REGNUM
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{ "fp", FP_REGNUM },
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#endif
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#ifdef SP_REGNUM
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{ "sp", SP_REGNUM },
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#endif
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#ifdef PS_REGNUM
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{ "ps", PS_REGNUM },
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#endif
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||
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};
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||
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unsigned num_std_regs = (sizeof std_regs / sizeof std_regs[0]);
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#endif
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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 ()
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{
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register 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 ()
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{
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register int val = arglist_len;
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register 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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free ((PTR)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 ()
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{
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register 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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free ((PTR)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 (expelt)
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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 (expelt)
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enum exp_opcode expelt;
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{
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union exp_element tmp;
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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 (expelt)
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struct symbol *expelt;
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{
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union exp_element tmp;
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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 (b)
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struct block *b;
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{
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union exp_element tmp;
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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_longcst (expelt)
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LONGEST expelt;
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{
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union exp_element tmp;
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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 (expelt)
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DOUBLEST expelt;
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{
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union exp_element tmp;
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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_type (expelt)
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struct type *expelt;
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{
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union exp_element tmp;
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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 (expelt)
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struct internalvar *expelt;
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{
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union exp_element tmp;
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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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||
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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 (str)
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struct stoken str;
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{
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register int len = str.length;
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register int lenelt;
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register 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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||
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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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||
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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.
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||
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Bitstring constants are stored by first writing an expression element
|
||
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. */
|
||
|
||
void
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||
write_exp_bitstring (str)
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struct stoken str;
|
||
{
|
||
register int bits = str.length; /* length in bits */
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register int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
|
||
register int lenelt;
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||
register 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);
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||
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. The rationale behind passing in text_symbol_type and
|
||
data_symbol_type was so that Modula-2 could pass in WORD for
|
||
data_symbol_type. Perhaps it still is useful to have those types vary
|
||
based on the language, but they no longer have names like "int", so
|
||
the initial rationale is gone. */
|
||
|
||
static struct type *msym_text_symbol_type;
|
||
static struct type *msym_data_symbol_type;
|
||
static struct type *msym_unknown_symbol_type;
|
||
|
||
void
|
||
write_exp_msymbol (msymbol, text_symbol_type, data_symbol_type)
|
||
struct minimal_symbol *msymbol;
|
||
struct type *text_symbol_type;
|
||
struct type *data_symbol_type;
|
||
{
|
||
write_exp_elt_opcode (OP_LONG);
|
||
write_exp_elt_type (lookup_pointer_type (builtin_type_void));
|
||
write_exp_elt_longcst ((LONGEST) SYMBOL_VALUE_ADDRESS (msymbol));
|
||
write_exp_elt_opcode (OP_LONG);
|
||
|
||
write_exp_elt_opcode (UNOP_MEMVAL);
|
||
switch (msymbol -> type)
|
||
{
|
||
case mst_text:
|
||
case mst_file_text:
|
||
case mst_solib_trampoline:
|
||
write_exp_elt_type (msym_text_symbol_type);
|
||
break;
|
||
|
||
case mst_data:
|
||
case mst_file_data:
|
||
case mst_bss:
|
||
case mst_file_bss:
|
||
write_exp_elt_type (msym_data_symbol_type);
|
||
break;
|
||
|
||
default:
|
||
write_exp_elt_type (msym_unknown_symbol_type);
|
||
break;
|
||
}
|
||
write_exp_elt_opcode (UNOP_MEMVAL);
|
||
}
|
||
|
||
/* 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 (str)
|
||
struct stoken str;
|
||
{
|
||
/* 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. */
|
||
for (i = 0; i < NUM_REGS; i++)
|
||
if (str.length - 1 == strlen (reg_names[i])
|
||
&& STREQN (str.ptr + 1, reg_names[i], str.length - 1))
|
||
{
|
||
goto handle_register;
|
||
}
|
||
for (i = 0; i < num_std_regs; i++)
|
||
if (str.length - 1 == strlen (std_regs[i].name)
|
||
&& STREQN (str.ptr + 1, std_regs[i].name, str.length - 1))
|
||
{
|
||
i = std_regs[i].regnum;
|
||
goto handle_register;
|
||
}
|
||
|
||
/* Any other names starting in $ are debugger internal variables. */
|
||
|
||
write_exp_elt_opcode (OP_INTERNALVAR);
|
||
write_exp_elt_intern (lookup_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);
|
||
write_exp_elt_longcst (i);
|
||
write_exp_elt_opcode (OP_REGISTER);
|
||
return;
|
||
}
|
||
|
||
/* Return a null-terminated temporary copy of the name
|
||
of a string token. */
|
||
|
||
char *
|
||
copy_name (token)
|
||
struct stoken token;
|
||
{
|
||
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). */
|
||
|
||
static void
|
||
prefixify_expression (expr)
|
||
register struct expression *expr;
|
||
{
|
||
register int len =
|
||
sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
|
||
register struct expression *temp;
|
||
register int inpos = expr->nelts, outpos = 0;
|
||
|
||
temp = (struct expression *) alloca (len);
|
||
|
||
/* Copy the original expression into temp. */
|
||
memcpy (temp, expr, len);
|
||
|
||
prefixify_subexp (temp, expr, inpos, outpos);
|
||
}
|
||
|
||
/* Return the number of exp_elements in the subexpression of EXPR
|
||
whose last exp_element is at index ENDPOS - 1 in EXPR. */
|
||
|
||
static int
|
||
length_of_subexp (expr, endpos)
|
||
register struct expression *expr;
|
||
register int endpos;
|
||
{
|
||
register int oplen = 1;
|
||
register int args = 0;
|
||
register int i;
|
||
|
||
if (endpos < 1)
|
||
error ("?error in length_of_subexp");
|
||
|
||
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_VAR_VALUE:
|
||
oplen = 4;
|
||
break;
|
||
|
||
case OP_TYPE:
|
||
case OP_BOOL:
|
||
case OP_LAST:
|
||
case OP_REGISTER:
|
||
case OP_INTERNALVAR:
|
||
oplen = 3;
|
||
break;
|
||
|
||
case OP_COMPLEX:
|
||
oplen = 1;
|
||
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 UNOP_MAX:
|
||
case UNOP_MIN:
|
||
oplen = 3;
|
||
break;
|
||
|
||
case BINOP_VAL:
|
||
case UNOP_CAST:
|
||
case UNOP_MEMVAL:
|
||
oplen = 3;
|
||
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_M2_STRING:
|
||
case OP_STRING:
|
||
case OP_NAME:
|
||
case OP_EXPRSTRING:
|
||
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:
|
||
oplen = 2;
|
||
break;
|
||
|
||
default:
|
||
args = 1 + (i < (int) BINOP_END);
|
||
}
|
||
|
||
while (args > 0)
|
||
{
|
||
oplen += length_of_subexp (expr, endpos - oplen);
|
||
args--;
|
||
}
|
||
|
||
return oplen;
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
static void
|
||
prefixify_subexp (inexpr, outexpr, inend, outbeg)
|
||
register struct expression *inexpr;
|
||
struct expression *outexpr;
|
||
register int inend;
|
||
int outbeg;
|
||
{
|
||
register int oplen = 1;
|
||
register int args = 0;
|
||
register int i;
|
||
int *arglens;
|
||
enum exp_opcode opcode;
|
||
|
||
/* Compute how long the last operation is (in OPLEN),
|
||
and also how many preceding subexpressions serve as
|
||
arguments for it (in ARGS). */
|
||
|
||
opcode = inexpr->elts[inend - 1].opcode;
|
||
switch (opcode)
|
||
{
|
||
/* C++ */
|
||
case OP_SCOPE:
|
||
oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
|
||
oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
|
||
break;
|
||
|
||
case OP_LONG:
|
||
case OP_DOUBLE:
|
||
case OP_VAR_VALUE:
|
||
oplen = 4;
|
||
break;
|
||
|
||
case OP_TYPE:
|
||
case OP_BOOL:
|
||
case OP_LAST:
|
||
case OP_REGISTER:
|
||
case OP_INTERNALVAR:
|
||
oplen = 3;
|
||
break;
|
||
|
||
case OP_COMPLEX:
|
||
oplen = 1;
|
||
args = 2;
|
||
break;
|
||
|
||
case OP_FUNCALL:
|
||
case OP_F77_UNDETERMINED_ARGLIST:
|
||
oplen = 3;
|
||
args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
|
||
break;
|
||
|
||
case UNOP_MIN:
|
||
case UNOP_MAX:
|
||
oplen = 3;
|
||
break;
|
||
|
||
case UNOP_CAST:
|
||
case UNOP_MEMVAL:
|
||
oplen = 3;
|
||
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 STRUCTOP_STRUCT:
|
||
case STRUCTOP_PTR:
|
||
case OP_LABELED:
|
||
args = 1;
|
||
/* fall through */
|
||
case OP_M2_STRING:
|
||
case OP_STRING:
|
||
case OP_NAME:
|
||
case OP_EXPRSTRING:
|
||
oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
|
||
oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
|
||
break;
|
||
|
||
case OP_BITSTRING:
|
||
oplen = longest_to_int (inexpr->elts[inend - 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 (inexpr->elts[inend - 2].longconst);
|
||
args -= longest_to_int (inexpr->elts[inend - 3].longconst);
|
||
args += 1;
|
||
break;
|
||
|
||
case TERNOP_COND:
|
||
case TERNOP_SLICE:
|
||
case TERNOP_SLICE_COUNT:
|
||
args = 3;
|
||
break;
|
||
|
||
case BINOP_ASSIGN_MODIFY:
|
||
oplen = 3;
|
||
args = 2;
|
||
break;
|
||
|
||
/* Modula-2 */
|
||
case MULTI_SUBSCRIPT:
|
||
oplen = 3;
|
||
args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
|
||
break;
|
||
|
||
/* C++ */
|
||
case OP_THIS:
|
||
oplen = 2;
|
||
break;
|
||
|
||
default:
|
||
args = 1 + ((int) opcode < (int) BINOP_END);
|
||
}
|
||
|
||
/* 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;
|
||
|
||
/* 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++)
|
||
{
|
||
oplen = arglens[i];
|
||
inend += oplen;
|
||
prefixify_subexp (inexpr, outexpr, inend, outbeg);
|
||
outbeg += oplen;
|
||
}
|
||
}
|
||
|
||
/* 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 (stringptr, block, comma)
|
||
char **stringptr;
|
||
struct block *block;
|
||
int comma;
|
||
{
|
||
struct cleanup *old_chain;
|
||
|
||
lexptr = *stringptr;
|
||
|
||
paren_depth = 0;
|
||
type_stack_depth = 0;
|
||
|
||
comma_terminates = comma;
|
||
|
||
if (lexptr == 0 || *lexptr == 0)
|
||
error_no_arg ("expression to compute");
|
||
|
||
old_chain = make_cleanup (free_funcalls, 0);
|
||
funcall_chain = 0;
|
||
|
||
expression_context_block = block ? block : get_selected_block ();
|
||
|
||
namecopy = (char *) alloca (strlen (lexptr) + 1);
|
||
expout_size = 10;
|
||
expout_ptr = 0;
|
||
expout = (struct expression *)
|
||
xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size));
|
||
expout->language_defn = current_language;
|
||
make_cleanup (free_current_contents, &expout);
|
||
|
||
if (current_language->la_parser ())
|
||
current_language->la_error (NULL);
|
||
|
||
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. */
|
||
|
||
DUMP_EXPRESSION (expout, gdb_stdout, "before conversion to prefix form");
|
||
prefixify_expression (expout);
|
||
DUMP_EXPRESSION (expout, gdb_stdout, "after conversion to prefix form");
|
||
|
||
*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 (string)
|
||
char *string;
|
||
{
|
||
register struct expression *exp;
|
||
exp = parse_exp_1 (&string, 0, 0);
|
||
if (*string)
|
||
error ("Junk after end of expression.");
|
||
return exp;
|
||
}
|
||
|
||
/* Stuff for maintaining a stack of types. Currently just used by C, but
|
||
probably useful for any language which declares its types "backwards". */
|
||
|
||
void
|
||
push_type (tp)
|
||
enum type_pieces tp;
|
||
{
|
||
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));
|
||
}
|
||
type_stack[type_stack_depth++].piece = tp;
|
||
}
|
||
|
||
void
|
||
push_type_int (n)
|
||
int n;
|
||
{
|
||
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));
|
||
}
|
||
type_stack[type_stack_depth++].int_val = n;
|
||
}
|
||
|
||
enum type_pieces
|
||
pop_type ()
|
||
{
|
||
if (type_stack_depth)
|
||
return type_stack[--type_stack_depth].piece;
|
||
return tp_end;
|
||
}
|
||
|
||
int
|
||
pop_type_int ()
|
||
{
|
||
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 (follow_type)
|
||
struct type *follow_type;
|
||
{
|
||
int done = 0;
|
||
int array_size;
|
||
struct type *range_type;
|
||
|
||
while (!done)
|
||
switch (pop_type ())
|
||
{
|
||
case tp_end:
|
||
done = 1;
|
||
break;
|
||
case tp_pointer:
|
||
follow_type = lookup_pointer_type (follow_type);
|
||
break;
|
||
case tp_reference:
|
||
follow_type = lookup_reference_type (follow_type);
|
||
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_int, 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_TYPE(follow_type)
|
||
= BOUND_CANNOT_BE_DETERMINED;
|
||
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;
|
||
}
|
||
|
||
void
|
||
_initialize_parse ()
|
||
{
|
||
type_stack_size = 80;
|
||
type_stack_depth = 0;
|
||
type_stack = (union type_stack_elt *)
|
||
xmalloc (type_stack_size * sizeof (*type_stack));
|
||
|
||
msym_text_symbol_type =
|
||
init_type (TYPE_CODE_FUNC, 1, 0, "<text variable, no debug info>", NULL);
|
||
TYPE_TARGET_TYPE (msym_text_symbol_type) = builtin_type_int;
|
||
msym_data_symbol_type =
|
||
init_type (TYPE_CODE_INT, TARGET_INT_BIT / HOST_CHAR_BIT, 0,
|
||
"<data variable, no debug info>", NULL);
|
||
msym_unknown_symbol_type =
|
||
init_type (TYPE_CODE_INT, 1, 0,
|
||
"<variable (not text or data), no debug info>",
|
||
NULL);
|
||
}
|