1 /* Copyright (C) 2002, 2003, 2004, 2005
2 Free Software Foundation, Inc.
3 Contributed by Andy Vaught
5 This file is part of the GNU Fortran 95 runtime library (libgfortran).
7 Libgfortran is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 In addition to the permissions in the GNU General Public License, the
13 Free Software Foundation gives you unlimited permission to link the
14 compiled version of this file into combinations with other programs,
15 and to distribute those combinations without any restriction coming
16 from the use of this file. (The General Public License restrictions
17 do apply in other respects; for example, they cover modification of
18 the file, and distribution when not linked into a combine
21 Libgfortran is distributed in the hope that it will be useful,
22 but WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 GNU General Public License for more details.
26 You should have received a copy of the GNU General Public License
27 along with Libgfortran; see the file COPYING. If not, write to
28 the Free Software Foundation, 59 Temple Place - Suite 330,
29 Boston, MA 02111-1307, USA. */
32 /* format.c-- parse a FORMAT string into a binary format suitable for
33 * interpretation during I/O statements */
38 #include "libgfortran.h"
43 /* Number of format nodes that we can store statically before we have
44 * to resort to dynamic allocation. The root node is array[0]. */
46 #define FARRAY_SIZE 200
48 static fnode *avail, array[FARRAY_SIZE];
50 /* Local variables for checking format strings. The saved_token is
51 * used to back up by a single format token during the parsing process. */
53 static char *format_string, *string;
54 static const char *error;
55 static format_token saved_token;
56 static int value, format_string_len, reversion_ok;
58 static fnode *saved_format;
59 static fnode colon_node = { FMT_COLON, 0, NULL, NULL, {{ 0, 0, 0 }}, 0,
64 static char posint_required[] = "Positive width required in format",
65 period_required[] = "Period required in format",
66 nonneg_required[] = "Nonnegative width required in format",
67 unexpected_element[] = "Unexpected element in format",
68 unexpected_end[] = "Unexpected end of format string",
69 bad_string[] = "Unterminated character constant in format",
70 bad_hollerith[] = "Hollerith constant extends past the end of the format",
71 reversion_error[] = "Exhausted data descriptors in format";
74 /* next_char()-- Return the next character in the format string.
75 * Returns -1 when the string is done. If the literal flag is set,
76 * spaces are significant, otherwise they are not. */
79 next_char (int literal)
85 if (format_string_len == 0)
89 c = toupper (*format_string++);
91 while (c == ' ' && !literal);
97 /* unget_char()-- Back up one character position. */
99 #define unget_char() { format_string--; format_string_len++; }
102 /* get_fnode()-- Allocate a new format node, inserting it into the
103 * current singly linked list. These are initially allocated from the
107 get_fnode (fnode ** head, fnode ** tail, format_token t)
111 if (avail - array >= FARRAY_SIZE)
112 f = get_mem (sizeof (fnode));
116 memset (f, '\0', sizeof (fnode));
129 f->source = format_string;
134 /* free_fnode()-- Recursive function to free the given fnode and
135 * everything it points to. We only have to actually free something
136 * if it is outside of the static array. */
139 free_fnode (fnode * f)
147 if (f->format == FMT_LPAREN)
148 free_fnode (f->u.child);
149 if (f < array || f >= array + FARRAY_SIZE)
155 /* free_fnodes()-- Free the current tree of fnodes. We only have to
156 * traverse the tree if some nodes were allocated dynamically. */
161 if (avail - array >= FARRAY_SIZE)
162 free_fnode (&array[0]);
165 memset(array, 0, sizeof(avail[0]) * FARRAY_SIZE);
169 /* format_lex()-- Simple lexical analyzer for getting the next token
170 * in a FORMAT string. We support a one-level token pushback in the
171 * saved_token variable. */
181 if (saved_token != FMT_NONE)
184 saved_token = FMT_NONE;
213 value = 10 * value + c - '0';
220 token = FMT_SIGNED_INT;
241 value = 10 * value + c - '0';
245 token = (value == 0) ? FMT_ZERO : FMT_POSINT;
269 switch (next_char (0))
298 switch (next_char (0))
315 switch (next_char (0))
335 string = format_string;
336 value = 0; /* This is the length of the string */
343 token = FMT_BADSTRING;
354 token = FMT_BADSTRING;
393 switch (next_char (0))
442 /* parse_format_list()-- Parse a format list. Assumes that a left
443 * paren has already been seen. Returns a list representing the
444 * parenthesis node which contains the rest of the list. */
447 parse_format_list (void)
450 format_token t, u, t2;
455 /* Get the next format item */
468 get_fnode (&head, &tail, FMT_LPAREN);
469 tail->repeat = repeat;
470 tail->u.child = parse_format_list ();
477 get_fnode (&head, &tail, FMT_SLASH);
478 tail->repeat = repeat;
482 get_fnode (&head, &tail, FMT_X);
495 get_fnode (&head, &tail, FMT_LPAREN);
497 tail->u.child = parse_format_list ();
503 case FMT_SIGNED_INT: /* Signed integer can only precede a P format. */
504 case FMT_ZERO: /* Same for zero. */
508 error = "Expected P edit descriptor in format";
513 get_fnode (&head, &tail, FMT_P);
518 if (t == FMT_F || t == FMT_EN || t == FMT_ES || t == FMT_D
519 || t == FMT_G || t == FMT_E)
528 case FMT_P: /* P and X require a prior number */
529 error = "P descriptor requires leading scale factor";
536 If we would be pedantic in the library, we would have to reject
537 an X descriptor without an integer prefix:
539 error = "X descriptor requires leading space count";
542 However, this is an extension supported by many Fortran compilers,
543 including Cray, HP, AIX, and IRIX. Therefore, we allow it in the
544 runtime library, and make the front end reject it if the compiler
545 is in pedantic mode. The interpretation of 'X' is '1X'.
547 get_fnode (&head, &tail, FMT_X);
553 get_fnode (&head, &tail, FMT_STRING);
555 tail->u.string.p = string;
556 tail->u.string.length = value;
565 get_fnode (&head, &tail, t);
570 get_fnode (&head, &tail, FMT_COLON);
575 get_fnode (&head, &tail, FMT_SLASH);
581 get_fnode (&head, &tail, FMT_DOLLAR);
588 if (t2 != FMT_POSINT)
590 error = posint_required;
593 get_fnode (&head, &tail, t);
614 get_fnode (&head, &tail, FMT_STRING);
616 if (format_string_len < 1)
618 error = bad_hollerith;
622 tail->u.string.p = format_string;
623 tail->u.string.length = 1;
632 error = unexpected_end;
642 error = unexpected_element;
646 /* In this state, t must currently be a data descriptor. Deal with
647 things that can/must follow the descriptor */
655 error = "Repeat count cannot follow P descriptor";
660 get_fnode (&head, &tail, FMT_P);
668 error = posint_required;
672 get_fnode (&head, &tail, FMT_L);
674 tail->repeat = repeat;
682 value = -1; /* Width not present */
685 get_fnode (&head, &tail, FMT_A);
686 tail->repeat = repeat;
696 get_fnode (&head, &tail, t);
697 tail->repeat = repeat;
700 if (t == FMT_F || g.mode == WRITING)
702 if (u != FMT_POSINT && u != FMT_ZERO)
704 error = nonneg_required;
712 error = posint_required;
717 tail->u.real.w = value;
722 error = period_required;
727 if (t != FMT_ZERO && t != FMT_POSINT)
729 error = nonneg_required;
733 tail->u.real.d = value;
735 if (t == FMT_D || t == FMT_F)
740 /* Look for optional exponent */
749 error = "Positive exponent width required in format";
753 tail->u.real.e = value;
759 if (repeat > format_string_len)
761 error = bad_hollerith;
765 get_fnode (&head, &tail, FMT_STRING);
767 tail->u.string.p = format_string;
768 tail->u.string.length = repeat;
771 format_string += value;
772 format_string_len -= repeat;
780 get_fnode (&head, &tail, t);
781 tail->repeat = repeat;
785 if (g.mode == READING)
789 error = posint_required;
795 if (t != FMT_ZERO && t != FMT_POSINT)
797 error = nonneg_required;
802 tail->u.integer.w = value;
803 tail->u.integer.m = -1;
813 if (t != FMT_ZERO && t != FMT_POSINT)
815 error = nonneg_required;
819 tail->u.integer.m = value;
822 if (tail->u.integer.w != 0 && tail->u.integer.m > tail->u.integer.w)
824 error = "Minimum digits exceeds field width";
831 error = unexpected_element;
835 /* Between a descriptor and what comes next */
847 get_fnode (&head, &tail, FMT_SLASH);
856 error = unexpected_end;
860 /* Assume a missing comma, this is a GNU extension */
864 /* Optional comma is a weird between state where we've just finished
865 reading a colon, slash or P descriptor. */
876 default: /* Assume that we have another format item */
888 /* format_error()-- Generate an error message for a format statement.
889 * If the node that gives the location of the error is NULL, the error
890 * is assumed to happen at parse time, and the current location of the
893 * After freeing any dynamically allocated fnodes, generate a message
894 * showing where the problem is. We take extra care to print only the
895 * relevant part of the format if it is longer than a standard 80
899 format_error (fnode * f, const char *message)
901 int width, i, j, offset;
902 char *p, buffer[300];
905 format_string = f->source;
909 st_sprintf (buffer, "%s\n", message);
911 j = format_string - ioparm.format;
913 offset = (j > 60) ? j - 40 : 0;
916 width = ioparm.format_len - offset;
921 /* Show the format */
923 p = strchr (buffer, '\0');
925 memcpy (p, ioparm.format + offset, width);
930 /* Show where the problem is */
932 for (i = 1; i < j; i++)
938 generate_error (ERROR_FORMAT, buffer);
942 /* parse_format()-- Parse a format string. */
947 format_string = ioparm.format;
948 format_string_len = ioparm.format_len;
950 saved_token = FMT_NONE;
953 /* Initialize variables used during traversal of the tree */
956 g.reversion_flag = 0;
959 /* Allocate the first format node as the root of the tree */
963 avail->format = FMT_LPAREN;
967 if (format_lex () == FMT_LPAREN)
968 array[0].u.child = parse_format_list ();
970 error = "Missing initial left parenthesis in format";
973 format_error (NULL, error);
977 /* revert()-- Do reversion of the format. Control reverts to the left
978 * parenthesis that matches the rightmost right parenthesis. From our
979 * tree structure, we are looking for the rightmost parenthesis node
980 * at the second level, the first level always being a single
981 * parenthesis node. If this node doesn't exit, we use the top
989 g.reversion_flag = 1;
993 for (f = array[0].u.child; f; f = f->next)
994 if (f->format == FMT_LPAREN)
997 /* If r is NULL because no node was found, the whole tree will be used */
999 array[0].current = r;
1004 /* next_format0()-- Get the next format node without worrying about
1005 * reversion. Returns NULL when we hit the end of the list.
1006 * Parenthesis nodes are incremented after the list has been
1007 * exhausted, other nodes are incremented before they are returned. */
1010 next_format0 (fnode * f)
1017 if (f->format != FMT_LPAREN)
1020 if (f->count <= f->repeat)
1027 /* Deal with a parenthesis node */
1029 for (; f->count < f->repeat; f->count++)
1031 if (f->current == NULL)
1032 f->current = f->u.child;
1034 for (; f->current != NULL; f->current = f->current->next)
1036 r = next_format0 (f->current);
1047 /* next_format()-- Return the next format node. If the format list
1048 * ends up being exhausted, we do reversion. Reversion is only
1049 * allowed if the we've seen a data descriptor since the
1050 * initialization or the last reversion. We return NULL if the there
1051 * are no more data descriptors to return (which is an error
1060 if (saved_format != NULL)
1061 { /* Deal with a pushed-back format node */
1063 saved_format = NULL;
1067 f = next_format0 (&array[0]);
1078 f = next_format0 (&array[0]);
1081 format_error (NULL, reversion_error);
1085 /* Push the first reverted token and return a colon node in case
1086 * there are no more data items. */
1092 /* If this is a data edit descriptor, then reversion has become OK. */
1096 if (!reversion_ok &&
1097 (t == FMT_I || t == FMT_B || t == FMT_O || t == FMT_Z || t == FMT_F ||
1098 t == FMT_E || t == FMT_EN || t == FMT_ES || t == FMT_G || t == FMT_L ||
1099 t == FMT_A || t == FMT_D))
1105 /* unget_format()-- Push the given format back so that it will be
1106 * returned on the next call to next_format() without affecting
1107 * counts. This is necessary when we've encountered a data
1108 * descriptor, but don't know what the data item is yet. The format
1109 * node is pushed back, and we return control to the main program,
1110 * which calls the library back with the data item (or not). */
1113 unget_format (fnode * f)
1123 static void dump_format1 (fnode * f);
1125 /* dump_format0()-- Dump a single format node */
1128 dump_format0 (fnode * f)
1139 st_printf (" %d/", f->u.r);
1145 st_printf (" T%d", f->u.n);
1148 st_printf (" TR%d", f->u.n);
1151 st_printf (" TL%d", f->u.n);
1154 st_printf (" %dX", f->u.n);
1170 st_printf (" %d(", f->repeat);
1172 dump_format1 (f->u.child);
1179 for (i = f->u.string.length; i > 0; i--)
1180 st_printf ("%c", *p++);
1186 st_printf (" %dP", f->u.k);
1189 st_printf (" %dI%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1193 st_printf (" %dB%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1197 st_printf (" %dO%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1201 st_printf (" %dZ%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1211 st_printf (" %dD%d.%d", f->repeat, f->u.real.w, f->u.real.d);
1215 st_printf (" %dEN%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1220 st_printf (" %dES%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1225 st_printf (" %dF%d.%d", f->repeat, f->u.real.w, f->u.real.d);
1229 st_printf (" %dE%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1234 st_printf (" %dG%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1239 st_printf (" %dL%d", f->repeat, f->u.w);
1242 st_printf (" %dA%d", f->repeat, f->u.w);
1252 /* dump_format1()-- Dump a string of format nodes */
1255 dump_format1 (fnode * f)
1257 for (; f; f = f->next)
1261 /* dump_format()-- Dump the whole format node tree */
1266 st_printf ("format = ");
1267 dump_format0 (&array[0]);
1278 for (i = 0; i < 20; i++)
1283 st_printf ("No format!\n");