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);
589 if (t2 != FMT_POSINT)
591 error = posint_required;
594 get_fnode (&head, &tail, t);
615 get_fnode (&head, &tail, FMT_STRING);
617 if (format_string_len < 1)
619 error = bad_hollerith;
623 tail->u.string.p = format_string;
624 tail->u.string.length = 1;
633 error = unexpected_end;
643 error = unexpected_element;
647 /* In this state, t must currently be a data descriptor. Deal with
648 things that can/must follow the descriptor */
656 error = "Repeat count cannot follow P descriptor";
661 get_fnode (&head, &tail, FMT_P);
669 error = posint_required;
673 get_fnode (&head, &tail, FMT_L);
675 tail->repeat = repeat;
683 value = -1; /* Width not present */
686 get_fnode (&head, &tail, FMT_A);
687 tail->repeat = repeat;
697 get_fnode (&head, &tail, t);
698 tail->repeat = repeat;
701 if (t == FMT_F || g.mode == WRITING)
703 if (u != FMT_POSINT && u != FMT_ZERO)
705 error = nonneg_required;
713 error = posint_required;
718 tail->u.real.w = value;
723 error = period_required;
728 if (t != FMT_ZERO && t != FMT_POSINT)
730 error = nonneg_required;
734 tail->u.real.d = value;
736 if (t == FMT_D || t == FMT_F)
741 /* Look for optional exponent */
750 error = "Positive exponent width required in format";
754 tail->u.real.e = value;
760 if (repeat > format_string_len)
762 error = bad_hollerith;
766 get_fnode (&head, &tail, FMT_STRING);
768 tail->u.string.p = format_string;
769 tail->u.string.length = repeat;
772 format_string += value;
773 format_string_len -= repeat;
781 get_fnode (&head, &tail, t);
782 tail->repeat = repeat;
786 if (g.mode == READING)
790 error = posint_required;
796 if (t != FMT_ZERO && t != FMT_POSINT)
798 error = nonneg_required;
803 tail->u.integer.w = value;
804 tail->u.integer.m = -1;
814 if (t != FMT_ZERO && t != FMT_POSINT)
816 error = nonneg_required;
820 tail->u.integer.m = value;
823 if (tail->u.integer.w != 0 && tail->u.integer.m > tail->u.integer.w)
825 error = "Minimum digits exceeds field width";
832 error = unexpected_element;
836 /* Between a descriptor and what comes next */
848 get_fnode (&head, &tail, FMT_SLASH);
857 error = unexpected_end;
861 /* Assume a missing comma, this is a GNU extension */
865 /* Optional comma is a weird between state where we've just finished
866 reading a colon, slash or P descriptor. */
877 default: /* Assume that we have another format item */
889 /* format_error()-- Generate an error message for a format statement.
890 * If the node that gives the location of the error is NULL, the error
891 * is assumed to happen at parse time, and the current location of the
894 * After freeing any dynamically allocated fnodes, generate a message
895 * showing where the problem is. We take extra care to print only the
896 * relevant part of the format if it is longer than a standard 80
900 format_error (fnode * f, const char *message)
902 int width, i, j, offset;
903 char *p, buffer[300];
906 format_string = f->source;
910 st_sprintf (buffer, "%s\n", message);
912 j = format_string - ioparm.format;
914 offset = (j > 60) ? j - 40 : 0;
917 width = ioparm.format_len - offset;
922 /* Show the format */
924 p = strchr (buffer, '\0');
926 memcpy (p, ioparm.format + offset, width);
931 /* Show where the problem is */
933 for (i = 1; i < j; i++)
939 generate_error (ERROR_FORMAT, buffer);
943 /* parse_format()-- Parse a format string. */
948 format_string = ioparm.format;
949 format_string_len = ioparm.format_len;
951 saved_token = FMT_NONE;
954 /* Initialize variables used during traversal of the tree */
957 g.reversion_flag = 0;
960 /* Allocate the first format node as the root of the tree */
964 avail->format = FMT_LPAREN;
968 if (format_lex () == FMT_LPAREN)
969 array[0].u.child = parse_format_list ();
971 error = "Missing initial left parenthesis in format";
974 format_error (NULL, error);
978 /* revert()-- Do reversion of the format. Control reverts to the left
979 * parenthesis that matches the rightmost right parenthesis. From our
980 * tree structure, we are looking for the rightmost parenthesis node
981 * at the second level, the first level always being a single
982 * parenthesis node. If this node doesn't exit, we use the top
990 g.reversion_flag = 1;
994 for (f = array[0].u.child; f; f = f->next)
995 if (f->format == FMT_LPAREN)
998 /* If r is NULL because no node was found, the whole tree will be used */
1000 array[0].current = r;
1005 /* next_format0()-- Get the next format node without worrying about
1006 * reversion. Returns NULL when we hit the end of the list.
1007 * Parenthesis nodes are incremented after the list has been
1008 * exhausted, other nodes are incremented before they are returned. */
1011 next_format0 (fnode * f)
1018 if (f->format != FMT_LPAREN)
1021 if (f->count <= f->repeat)
1028 /* Deal with a parenthesis node */
1030 for (; f->count < f->repeat; f->count++)
1032 if (f->current == NULL)
1033 f->current = f->u.child;
1035 for (; f->current != NULL; f->current = f->current->next)
1037 r = next_format0 (f->current);
1048 /* next_format()-- Return the next format node. If the format list
1049 * ends up being exhausted, we do reversion. Reversion is only
1050 * allowed if the we've seen a data descriptor since the
1051 * initialization or the last reversion. We return NULL if the there
1052 * are no more data descriptors to return (which is an error
1061 if (saved_format != NULL)
1062 { /* Deal with a pushed-back format node */
1064 saved_format = NULL;
1068 f = next_format0 (&array[0]);
1079 f = next_format0 (&array[0]);
1082 format_error (NULL, reversion_error);
1086 /* Push the first reverted token and return a colon node in case
1087 * there are no more data items. */
1093 /* If this is a data edit descriptor, then reversion has become OK. */
1097 if (!reversion_ok &&
1098 (t == FMT_I || t == FMT_B || t == FMT_O || t == FMT_Z || t == FMT_F ||
1099 t == FMT_E || t == FMT_EN || t == FMT_ES || t == FMT_G || t == FMT_L ||
1100 t == FMT_A || t == FMT_D))
1106 /* unget_format()-- Push the given format back so that it will be
1107 * returned on the next call to next_format() without affecting
1108 * counts. This is necessary when we've encountered a data
1109 * descriptor, but don't know what the data item is yet. The format
1110 * node is pushed back, and we return control to the main program,
1111 * which calls the library back with the data item (or not). */
1114 unget_format (fnode * f)
1124 static void dump_format1 (fnode * f);
1126 /* dump_format0()-- Dump a single format node */
1129 dump_format0 (fnode * f)
1140 st_printf (" %d/", f->u.r);
1146 st_printf (" T%d", f->u.n);
1149 st_printf (" TR%d", f->u.n);
1152 st_printf (" TL%d", f->u.n);
1155 st_printf (" %dX", f->u.n);
1171 st_printf (" %d(", f->repeat);
1173 dump_format1 (f->u.child);
1180 for (i = f->u.string.length; i > 0; i--)
1181 st_printf ("%c", *p++);
1187 st_printf (" %dP", f->u.k);
1190 st_printf (" %dI%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1194 st_printf (" %dB%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1198 st_printf (" %dO%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1202 st_printf (" %dZ%d.%d", f->repeat, f->u.integer.w, f->u.integer.m);
1212 st_printf (" %dD%d.%d", f->repeat, f->u.real.w, f->u.real.d);
1216 st_printf (" %dEN%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1221 st_printf (" %dES%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1226 st_printf (" %dF%d.%d", f->repeat, f->u.real.w, f->u.real.d);
1230 st_printf (" %dE%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1235 st_printf (" %dG%d.%dE%d", f->repeat, f->u.real.w, f->u.real.d,
1240 st_printf (" %dL%d", f->repeat, f->u.w);
1243 st_printf (" %dA%d", f->repeat, f->u.w);
1253 /* dump_format1()-- Dump a string of format nodes */
1256 dump_format1 (fnode * f)
1258 for (; f; f = f->next)
1262 /* dump_format()-- Dump the whole format node tree */
1267 st_printf ("format = ");
1268 dump_format0 (&array[0]);
1279 for (i = 0; i < 20; i++)
1284 st_printf ("No format!\n");