/* Tree browser.
Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
Contributed by Sebastian Pop <s.pop@laposte.net>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "tree-inline.h"
#include "diagnostic.h"
#include "hashtab.h"
#define TB_OUT_FILE stdout
#define TB_IN_FILE stdin
#define TB_NIY fprintf (TB_OUT_FILE, "Sorry this command is not yet implemented.\n")
#define TB_WF fprintf (TB_OUT_FILE, "Warning, this command failed.\n")
/* Structures for handling Tree Browser's commands. */
#define DEFTBCODE(COMMAND, STRING, HELP) COMMAND,
enum TB_Comm_code {
#include "tree-browser.def"
TB_UNUSED_COMMAND
};
#undef DEFTBCODE
typedef enum TB_Comm_code TB_CODE;
struct tb_command {
const char *help_msg;
const char *comm_text;
size_t comm_len;
TB_CODE comm_code;
};
#define DEFTBCODE(code, str, help) { help, str, sizeof(str) - 1, code },
static const struct tb_command tb_commands[] =
{
#include "tree-browser.def"
};
#undef DEFTBCODE
#define TB_COMMAND_LEN(N) (tb_commands[N].comm_len)
#define TB_COMMAND_TEXT(N) (tb_commands[N].comm_text)
#define TB_COMMAND_CODE(N) (tb_commands[N].comm_code)
#define TB_COMMAND_HELP(N) (tb_commands[N].help_msg)
/* Next structure is for parsing TREE_CODEs. */
struct tb_tree_code {
enum tree_code code;
const char *code_string;
size_t code_string_len;
};
#define DEFTREECODE(SYM, STRING, TYPE, NARGS) { SYM, STRING, sizeof (STRING) - 1 },
static const struct tb_tree_code tb_tree_codes[] =
{
#include "tree.def"
};
#undef DEFTREECODE
#define TB_TREE_CODE(N) (tb_tree_codes[N].code)
#define TB_TREE_CODE_TEXT(N) (tb_tree_codes[N].code_string)
#define TB_TREE_CODE_LEN(N) (tb_tree_codes[N].code_string_len)
/* Function declarations. */
static long TB_getline (char **, long *, FILE *);
static TB_CODE TB_get_command (char *);
static enum tree_code TB_get_tree_code (char *);
static tree find_node_with_code (tree *, int *, void *);
static tree store_child_info (tree *, int *, void *);
static void TB_update_up (tree);
static tree TB_current_chain_node (tree);
static tree TB_prev_expr (tree);
static tree TB_next_expr (tree);
static tree TB_up_expr (tree);
static tree TB_first_in_bind (tree);
static tree TB_last_in_bind (tree);
static int TB_parent_eq (const void *, const void *);
static tree TB_history_prev (void);
/* FIXME: To be declared in a .h file. */
void browse_tree (tree);
/* Static variables. */
static htab_t TB_up_ht;
static tree TB_history_stack = NULL_TREE;
static int TB_verbose = 1;
/* Entry point in the Tree Browser. */
void
browse_tree (tree begin)
{
tree head;
TB_CODE tbc = TB_UNUSED_COMMAND;
ssize_t rd;
char *input = NULL;
long input_size = 0;
fprintf (TB_OUT_FILE, "\nTree Browser\n");
#define TB_SET_HEAD(N) do { \
TB_history_stack = tree_cons (NULL_TREE, (N), TB_history_stack); \
head = N; \
if (TB_verbose) \
if (head) \
{ \
print_generic_expr (TB_OUT_FILE, head, 0); \
fprintf (TB_OUT_FILE, "\n"); \
} \
} while (0)
TB_SET_HEAD (begin);
/* Store in a hashtable information about previous and upper statements. */
{
TB_up_ht = htab_create (1023, htab_hash_pointer, &TB_parent_eq, NULL);
TB_update_up (head);
}
while (24)
{
fprintf (TB_OUT_FILE, "TB> ");
rd = TB_getline (&input, &input_size, TB_IN_FILE);
if (rd == -1)
/* EOF. */
goto ret;
if (rd != 1)
/* Get a new command. Otherwise the user just pressed enter, and thus
she expects the last command to be reexecuted. */
tbc = TB_get_command (input);
switch (tbc)
{
case TB_UPDATE_UP:
TB_update_up (head);
break;
case TB_MAX:
if (head && (INTEGRAL_TYPE_P (head)
|| TREE_CODE (head) == REAL_TYPE))
TB_SET_HEAD (TYPE_MAX_VALUE (head));
else
TB_WF;
break;
case TB_MIN:
if (head && (INTEGRAL_TYPE_P (head)
|| TREE_CODE (head) == REAL_TYPE))
TB_SET_HEAD (TYPE_MIN_VALUE (head));
else
TB_WF;
break;
case TB_ELT:
if (head && TREE_CODE (head) == TREE_VEC)
{
/* This command takes another argument: the element number:
for example "elt 1". */
TB_NIY;
}
else if (head && TREE_CODE (head) == VECTOR_CST)
{
/* This command takes another argument: the element number:
for example "elt 1". */
TB_NIY;
}
else
TB_WF;
break;
case TB_VALUE:
if (head && TREE_CODE (head) == TREE_LIST)
TB_SET_HEAD (TREE_VALUE (head));
else
TB_WF;
break;
case TB_PURPOSE:
if (head && TREE_CODE (head) == TREE_LIST)
TB_SET_HEAD (TREE_PURPOSE (head));
else
TB_WF;
break;
case TB_IMAG:
if (head && TREE_CODE (head) == COMPLEX_CST)
TB_SET_HEAD (TREE_IMAGPART (head));
else
TB_WF;
break;
case TB_REAL:
if (head && TREE_CODE (head) == COMPLEX_CST)
TB_SET_HEAD (TREE_REALPART (head));
else
TB_WF;
break;
case TB_BLOCK:
if (head && TREE_CODE (head) == BIND_EXPR)
TB_SET_HEAD (TREE_OPERAND (head, 2));
else
TB_WF;
break;
case TB_SUBBLOCKS:
if (head && TREE_CODE (head) == BLOCK)
TB_SET_HEAD (BLOCK_SUBBLOCKS (head));
else
TB_WF;
break;
case TB_SUPERCONTEXT:
if (head && TREE_CODE (head) == BLOCK)
TB_SET_HEAD (BLOCK_SUPERCONTEXT (head));
else
TB_WF;
break;
case TB_VARS:
if (head && TREE_CODE (head) == BLOCK)
TB_SET_HEAD (BLOCK_VARS (head));
else if (head && TREE_CODE (head) == BIND_EXPR)
TB_SET_HEAD (TREE_OPERAND (head, 0));
else
TB_WF;
break;
case TB_REFERENCE_TO_THIS:
if (head && TYPE_P (head))
TB_SET_HEAD (TYPE_REFERENCE_TO (head));
else
TB_WF;
break;
case TB_POINTER_TO_THIS:
if (head && TYPE_P (head))
TB_SET_HEAD (TYPE_POINTER_TO (head));
else
TB_WF;
break;
case TB_BASETYPE:
if (head && TREE_CODE (head) == OFFSET_TYPE)
TB_SET_HEAD (TYPE_OFFSET_BASETYPE (head));
else
TB_WF;
break;
case TB_ARG_TYPES:
if (head && (TREE_CODE (head) == FUNCTION_TYPE
|| TREE_CODE (head) == METHOD_TYPE))
TB_SET_HEAD (TYPE_ARG_TYPES (head));
else
TB_WF;
break;
case TB_METHOD_BASE_TYPE:
if (head && (TREE_CODE (head) == FUNCTION_TYPE
|| TREE_CODE (head) == METHOD_TYPE)
&& TYPE_METHOD_BASETYPE (head))
TB_SET_HEAD (TYPE_METHOD_BASETYPE (head));
else
TB_WF;
break;
case TB_FIELDS:
if (head && (TREE_CODE (head) == RECORD_TYPE
|| TREE_CODE (head) == UNION_TYPE
|| TREE_CODE (head) == QUAL_UNION_TYPE))
TB_SET_HEAD (TYPE_FIELDS (head));
else
TB_WF;
break;
case TB_DOMAIN:
if (head && TREE_CODE (head) == ARRAY_TYPE)
TB_SET_HEAD (TYPE_DOMAIN (head));
else
TB_WF;
break;
case TB_VALUES:
if (head && TREE_CODE (head) == ENUMERAL_TYPE)
TB_SET_HEAD (TYPE_VALUES (head));
else
TB_WF;
break;
case TB_ARG_TYPE:
if (head && TREE_CODE (head) == PARM_DECL)
TB_SET_HEAD (DECL_ARG_TYPE (head));
else
TB_WF;
break;
case TB_INITIAL:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_INITIAL (head));
else
TB_WF;
break;
case TB_RESULT:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_RESULT_FLD (head));
else
TB_WF;
break;
case TB_ARGUMENTS:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_ARGUMENTS (head));
else
TB_WF;
break;
case TB_ABSTRACT_ORIGIN:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_ABSTRACT_ORIGIN (head));
else if (head && TREE_CODE (head) == BLOCK)
TB_SET_HEAD (BLOCK_ABSTRACT_ORIGIN (head));
else
TB_WF;
break;
case TB_ATTRIBUTES:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_ATTRIBUTES (head));
else if (head && TYPE_P (head))
TB_SET_HEAD (TYPE_ATTRIBUTES (head));
else
TB_WF;
break;
case TB_CONTEXT:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_CONTEXT (head));
else if (head && TYPE_P (head)
&& TYPE_CONTEXT (head))
TB_SET_HEAD (TYPE_CONTEXT (head));
else
TB_WF;
break;
case TB_OFFSET:
if (head && TREE_CODE (head) == FIELD_DECL)
TB_SET_HEAD (DECL_FIELD_OFFSET (head));
else
TB_WF;
break;
case TB_BIT_OFFSET:
if (head && TREE_CODE (head) == FIELD_DECL)
TB_SET_HEAD (DECL_FIELD_BIT_OFFSET (head));
else
TB_WF;
break;
case TB_UNIT_SIZE:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_SIZE_UNIT (head));
else if (head && TYPE_P (head))
TB_SET_HEAD (TYPE_SIZE_UNIT (head));
else
TB_WF;
break;
case TB_SIZE:
if (head && DECL_P (head))
TB_SET_HEAD (DECL_SIZE (head));
else if (head && TYPE_P (head))
TB_SET_HEAD (TYPE_SIZE (head));
else
TB_WF;
break;
case TB_TYPE:
if (head && TREE_TYPE (head))
TB_SET_HEAD (TREE_TYPE (head));
else
TB_WF;
break;
case TB_DECL_SAVED_TREE:
if (head && TREE_CODE (head) == FUNCTION_DECL
&& DECL_SAVED_TREE (head))
TB_SET_HEAD (DECL_SAVED_TREE (head));
else
TB_WF;
break;
case TB_BODY:
if (head && TREE_CODE (head) == BIND_EXPR)
TB_SET_HEAD (TREE_OPERAND (head, 1));
else
TB_WF;
break;
case TB_CHILD_0:
if (head && EXPR_P (head) && TREE_OPERAND (head, 0))
TB_SET_HEAD (TREE_OPERAND (head, 0));
else
TB_WF;
break;
case TB_CHILD_1:
if (head && EXPR_P (head) && TREE_OPERAND (head, 1))
TB_SET_HEAD (TREE_OPERAND (head, 1));
else
TB_WF;
break;
case TB_CHILD_2:
if (head && EXPR_P (head) && TREE_OPERAND (head, 2))
TB_SET_HEAD (TREE_OPERAND (head, 2));
else
TB_WF;
break;
case TB_CHILD_3:
if (head && EXPR_P (head) && TREE_OPERAND (head, 3))
TB_SET_HEAD (TREE_OPERAND (head, 3));
else
TB_WF;
break;
case TB_PRINT:
if (head)
debug_tree (head);
else
TB_WF;
break;
case TB_PRETTY_PRINT:
if (head)
{
print_generic_stmt (TB_OUT_FILE, head, 0);
fprintf (TB_OUT_FILE, "\n");
}
else
TB_WF;
break;
case TB_SEARCH_NAME:
break;
case TB_SEARCH_CODE:
{
enum tree_code code;
char *arg_text;
arg_text = strchr (input, ' ');
if (arg_text == NULL)
{
fprintf (TB_OUT_FILE, "First argument is missing. This isn't a valid search command. \n");
break;
}
code = TB_get_tree_code (arg_text + 1);
/* Search in the subtree a node with the given code. */
{
tree res;
res = walk_tree (&head, find_node_with_code, &code, NULL);
if (res == NULL_TREE)
{
fprintf (TB_OUT_FILE, "There's no node with this code (reachable via the walk_tree function from this node).\n");
}
else
{
fprintf (TB_OUT_FILE, "Achoo! I got this node in the tree.\n");
TB_SET_HEAD (res);
}
}
break;
}
#define TB_MOVE_HEAD(FCT) do { \
if (head) \
{ \
tree t; \
t = FCT (head); \
if (t) \
TB_SET_HEAD (t); \
else \
TB_WF; \
} \
else \
TB_WF; \
} while (0)
case TB_FIRST:
TB_MOVE_HEAD (TB_first_in_bind);
break;
case TB_LAST:
TB_MOVE_HEAD (TB_last_in_bind);
break;
case TB_UP:
TB_MOVE_HEAD (TB_up_expr);
break;
case TB_PREV:
TB_MOVE_HEAD (TB_prev_expr);
break;
case TB_NEXT:
TB_MOVE_HEAD (TB_next_expr);
break;
case TB_HPREV:
/* This command is a little bit special, since it deals with history
stack. For this reason it should keep the "head = ..." statement
and not use TB_MOVE_HEAD. */
if (head)
{
tree t;
t = TB_history_prev ();
if (t)
{
head = t;
if (TB_verbose)
{
print_generic_expr (TB_OUT_FILE, head, 0);
fprintf (TB_OUT_FILE, "\n");
}
}
else
TB_WF;
}
else
TB_WF;
break;
case TB_CHAIN:
/* Don't go further if it's the last node in this chain. */
if (head && TREE_CODE (head) == BLOCK)
TB_SET_HEAD (BLOCK_CHAIN (head));
else if (head && TREE_CHAIN (head))
TB_SET_HEAD (TREE_CHAIN (head));
else
TB_WF;
break;
case TB_FUN:
/* Go up to the current function declaration. */
TB_SET_HEAD (current_function_decl);
fprintf (TB_OUT_FILE, "Current function declaration.\n");
break;
case TB_HELP:
/* Display a help message. */
{
int i;
fprintf (TB_OUT_FILE, "Possible commands are:\n\n");
for (i = 0; i < TB_UNUSED_COMMAND; i++)
{
fprintf (TB_OUT_FILE, "%20s - %s\n", TB_COMMAND_TEXT (i), TB_COMMAND_HELP (i));
}
}
break;
case TB_VERBOSE:
if (TB_verbose == 0)
{
TB_verbose = 1;
fprintf (TB_OUT_FILE, "Verbose on.\n");
}
else
{
TB_verbose = 0;
fprintf (TB_OUT_FILE, "Verbose off.\n");
}
break;
case TB_EXIT:
case TB_QUIT:
/* Just exit from this function. */
goto ret;
default:
TB_NIY;
}
}
ret:;
htab_delete (TB_up_ht);
return;
}
/* Search the first node in this BIND_EXPR. */
static tree
TB_first_in_bind (tree node)
{
tree t;
if (node == NULL_TREE)
return NULL_TREE;
while ((t = TB_prev_expr (node)))
node = t;
return node;
}
/* Search the last node in this BIND_EXPR. */
static tree
TB_last_in_bind (tree node)
{
tree t;
if (node == NULL_TREE)
return NULL_TREE;
while ((t = TB_next_expr (node)))
node = t;
return node;
}
/* Search the parent expression for this node. */
static tree
TB_up_expr (tree node)
{
tree res;
if (node == NULL_TREE)
return NULL_TREE;
res = (tree) htab_find (TB_up_ht, node);
return res;
}
/* Search the previous expression in this BIND_EXPR. */
static tree
TB_prev_expr (tree node)
{
node = TB_current_chain_node (node);
if (node == NULL_TREE)
return NULL_TREE;
node = TB_up_expr (node);
if (node && TREE_CODE (node) == COMPOUND_EXPR)
return node;
else
return NULL_TREE;
}
/* Search the next expression in this BIND_EXPR. */
static tree
TB_next_expr (tree node)
{
node = TB_current_chain_node (node);
if (node == NULL_TREE)
return NULL_TREE;
node = TREE_OPERAND (node, 1);
return node;
}
static tree
TB_current_chain_node (tree node)
{
if (node == NULL_TREE)
return NULL_TREE;
if (TREE_CODE (node) == COMPOUND_EXPR)
return node;
node = TB_up_expr (node);
if (node)
{
if (TREE_CODE (node) == COMPOUND_EXPR)
return node;
node = TB_up_expr (node);
if (TREE_CODE (node) == COMPOUND_EXPR)
return node;
}
return NULL_TREE;
}
/* For each node store in its children nodes that the current node is their
parent. This function is used by walk_tree. */
static tree
store_child_info (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED)
{
tree node;
void **slot;
node = *tp;
/* 'node' is the parent of 'TREE_OPERAND (node, *)'. */
if (EXPRESSION_CLASS_P (node))
{
#define STORE_CHILD(N) do { \
tree op = TREE_OPERAND (node, N); \
slot = htab_find_slot (TB_up_ht, op, INSERT); \
*slot = (void *) node; \
} while (0)
switch (TREE_CODE_LENGTH (TREE_CODE (node)))
{
case 4:
STORE_CHILD (0);
STORE_CHILD (1);
STORE_CHILD (2);
STORE_CHILD (3);
break;
case 3:
STORE_CHILD (0);
STORE_CHILD (1);
STORE_CHILD (2);
break;
case 2:
STORE_CHILD (0);
STORE_CHILD (1);
break;
case 1:
STORE_CHILD (0);
break;
case 0:
default:
/* No children: nothing to do. */
break;
}
#undef STORE_CHILD
}
/* Never stop walk_tree. */
return NULL_TREE;
}
/* Function used in TB_up_ht. */
static int
TB_parent_eq (const void *p1, const void *p2)
{
tree node, parent;
node = (tree) p2;
parent = (tree) p1;
if (p1 == NULL || p2 == NULL)
return 0;
if (EXPRESSION_CLASS_P (parent))
{
#define TEST_CHILD(N) do { \
if (node == TREE_OPERAND (parent, N)) \
return 1; \
} while (0)
switch (TREE_CODE_LENGTH (TREE_CODE (parent)))
{
case 4:
TEST_CHILD (0);
TEST_CHILD (1);
TEST_CHILD (2);
TEST_CHILD (3);
break;
case 3:
TEST_CHILD (0);
TEST_CHILD (1);
TEST_CHILD (2);
break;
case 2:
TEST_CHILD (0);
TEST_CHILD (1);
break;
case 1:
TEST_CHILD (0);
break;
case 0:
default:
/* No children: nothing to do. */
break;
}
#undef TEST_CHILD
}
return 0;
}
/* Update information about upper expressions in the hash table. */
static void
TB_update_up (tree node)
{
while (node)
{
walk_tree (&node, store_child_info, NULL, NULL);
/* Walk function's body. */
if (TREE_CODE (node) == FUNCTION_DECL)
if (DECL_SAVED_TREE (node))
walk_tree (&DECL_SAVED_TREE (node), store_child_info, NULL, NULL);
/* Walk rest of the chain. */
node = TREE_CHAIN (node);
}
fprintf (TB_OUT_FILE, "Up/prev expressions updated.\n");
}
/* Parse the input string for determining the command the user asked for. */
static TB_CODE
TB_get_command (char *input)
{
unsigned int mn, size_tok;
int comp;
char *space;
space = strchr (input, ' ');
if (space != NULL)
size_tok = strlen (input) - strlen (space);
else
size_tok = strlen (input) - 1;
for (mn = 0; mn < TB_UNUSED_COMMAND; mn++)
{
if (size_tok != TB_COMMAND_LEN (mn))
continue;
comp = memcmp (input, TB_COMMAND_TEXT (mn), TB_COMMAND_LEN (mn));
if (comp == 0)
/* Here we just determined the command. If this command takes
an argument, then the argument is determined later. */
return TB_COMMAND_CODE (mn);
}
/* Not a valid command. */
return TB_UNUSED_COMMAND;
}
/* Parse the input string for determining the tree code. */
static enum tree_code
TB_get_tree_code (char *input)
{
unsigned int mn, size_tok;
int comp;
char *space;
space = strchr (input, ' ');
if (space != NULL)
size_tok = strlen (input) - strlen (space);
else
size_tok = strlen (input) - 1;
for (mn = 0; mn < LAST_AND_UNUSED_TREE_CODE; mn++)
{
if (size_tok != TB_TREE_CODE_LEN (mn))
continue;
comp = memcmp (input, TB_TREE_CODE_TEXT (mn), TB_TREE_CODE_LEN (mn));
if (comp == 0)
{
fprintf (TB_OUT_FILE, "%s\n", TB_TREE_CODE_TEXT (mn));
return TB_TREE_CODE (mn);
}
}
/* This isn't a valid code. */
return LAST_AND_UNUSED_TREE_CODE;
}
/* Find a node with a given code. This function is used as an argument to
walk_tree. */
static tree
find_node_with_code (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
void *data)
{
enum tree_code *code;
code = (enum tree_code *) data;
if (*code == TREE_CODE (*tp))
return *tp;
return NULL_TREE;
}
/* Returns a pointer to the last visited node. */
static tree
TB_history_prev (void)
{
if (TB_history_stack)
{
TB_history_stack = TREE_CHAIN (TB_history_stack);
if (TB_history_stack)
return TREE_VALUE (TB_history_stack);
}
return NULL_TREE;
}
/* Read up to (and including) a '\n' from STREAM into *LINEPTR
(and null-terminate it). *LINEPTR is a pointer returned from malloc
(or NULL), pointing to *N characters of space. It is realloc'd as
necessary. Returns the number of characters read (not including the
null terminator), or -1 on error or EOF.
This function comes from sed (and is supposed to be a portable version
of getline). */
static long
TB_getline (char **lineptr, long *n, FILE *stream)
{
char *line, *p;
long size, copy;
if (lineptr == NULL || n == NULL)
{
errno = EINVAL;
return -1;
}
if (ferror (stream))
return -1;
/* Make sure we have a line buffer to start with. */
if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars. */
{
#ifndef MAX_CANON
#define MAX_CANON 256
#endif
line = (char *) xrealloc (*lineptr, MAX_CANON);
if (line == NULL)
return -1;
*lineptr = line;
*n = MAX_CANON;
}
line = *lineptr;
size = *n;
copy = size;
p = line;
while (1)
{
long len;
while (--copy > 0)
{
register int c = getc (stream);
if (c == EOF)
goto lose;
else if ((*p++ = c) == '\n')
goto win;
}
/* Need to enlarge the line buffer. */
len = p - line;
size *= 2;
line = (char *) xrealloc (line, size);
if (line == NULL)
goto lose;
*lineptr = line;
*n = size;
p = line + len;
copy = size - len;
}
lose:
if (p == *lineptr)
return -1;
/* Return a partial line since we got an error in the middle. */
win:
#if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) || defined(MSDOS)
if (p - 2 >= *lineptr && p[-2] == '\r')
p[-2] = p[-1], --p;
#endif
*p = '\0';
return p - *lineptr;
}