2 Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation,
4 Contributed by Andy Vaught
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
32 /* Current statement label. Zero means no statement label. Because
33 new_st can get wiped during statement matching, we have to keep it
36 gfc_st_label *gfc_statement_label;
38 static locus label_locus;
41 gfc_state_data *gfc_state_stack;
43 /* TODO: Re-order functions to kill these forward decls. */
44 static void check_statement_label (gfc_statement);
45 static void undo_new_statement (void);
46 static void reject_statement (void);
48 /* A sort of half-matching function. We try to match the word on the
49 input with the passed string. If this succeeds, we call the
50 keyword-dependent matching function that will match the rest of the
51 statement. For single keywords, the matching subroutine is
55 match_word (const char *str, match (*subr) (void), locus * old_locus)
70 gfc_current_locus = *old_locus;
78 /* Figure out what the next statement is, (mostly) regardless of
81 #define match(keyword, subr, st) \
82 if (match_word(keyword, subr, &old_locus) == MATCH_YES) \
85 undo_new_statement ();
88 decode_statement (void)
99 gfc_clear_error (); /* Clear any pending errors. */
100 gfc_clear_warning (); /* Clear any pending warnings. */
102 if (gfc_match_eos () == MATCH_YES)
105 old_locus = gfc_current_locus;
107 /* Try matching a data declaration or function declaration. The
108 input "REALFUNCTIONA(N)" can mean several things in different
109 contexts, so it (and its relatives) get special treatment. */
111 if (gfc_current_state () == COMP_NONE
112 || gfc_current_state () == COMP_INTERFACE
113 || gfc_current_state () == COMP_CONTAINS)
115 m = gfc_match_function_decl ();
118 else if (m == MATCH_ERROR)
122 gfc_current_locus = old_locus;
125 /* Match statements whose error messages are meant to be overwritten
126 by something better. */
128 match (NULL, gfc_match_assignment, ST_ASSIGNMENT);
129 match (NULL, gfc_match_pointer_assignment, ST_POINTER_ASSIGNMENT);
130 match (NULL, gfc_match_st_function, ST_STATEMENT_FUNCTION);
132 match (NULL, gfc_match_data_decl, ST_DATA_DECL);
134 /* Try to match a subroutine statement, which has the same optional
135 prefixes that functions can have. */
137 if (gfc_match_subroutine () == MATCH_YES)
138 return ST_SUBROUTINE;
140 gfc_current_locus = old_locus;
142 /* Check for the IF, DO, SELECT, WHERE and FORALL statements, which
143 might begin with a block label. The match functions for these
144 statements are unusual in that their keyword is not seen before
145 the matcher is called. */
147 if (gfc_match_if (&st) == MATCH_YES)
150 gfc_current_locus = old_locus;
152 if (gfc_match_where (&st) == MATCH_YES)
155 gfc_current_locus = old_locus;
157 if (gfc_match_forall (&st) == MATCH_YES)
160 gfc_current_locus = old_locus;
162 match (NULL, gfc_match_do, ST_DO);
163 match (NULL, gfc_match_select, ST_SELECT_CASE);
165 /* General statement matching: Instead of testing every possible
166 statement, we eliminate most possibilities by peeking at the
169 c = gfc_peek_char ();
174 match ("allocate", gfc_match_allocate, ST_ALLOCATE);
175 match ("allocatable", gfc_match_allocatable, ST_ATTR_DECL);
176 match ("assign", gfc_match_assign, ST_LABEL_ASSIGNMENT);
180 match ("backspace", gfc_match_backspace, ST_BACKSPACE);
181 match ("block data", gfc_match_block_data, ST_BLOCK_DATA);
185 match ("call", gfc_match_call, ST_CALL);
186 match ("close", gfc_match_close, ST_CLOSE);
187 match ("continue", gfc_match_continue, ST_CONTINUE);
188 match ("cycle", gfc_match_cycle, ST_CYCLE);
189 match ("case", gfc_match_case, ST_CASE);
190 match ("common", gfc_match_common, ST_COMMON);
191 match ("contains", gfc_match_eos, ST_CONTAINS);
195 match ("deallocate", gfc_match_deallocate, ST_DEALLOCATE);
196 match ("data", gfc_match_data, ST_DATA);
197 match ("dimension", gfc_match_dimension, ST_ATTR_DECL);
201 match ("end file", gfc_match_endfile, ST_END_FILE);
202 match ("exit", gfc_match_exit, ST_EXIT);
203 match ("else", gfc_match_else, ST_ELSE);
204 match ("else where", gfc_match_elsewhere, ST_ELSEWHERE);
205 match ("else if", gfc_match_elseif, ST_ELSEIF);
207 if (gfc_match_end (&st) == MATCH_YES)
210 match ("entry% ", gfc_match_entry, ST_ENTRY);
211 match ("equivalence", gfc_match_equivalence, ST_EQUIVALENCE);
212 match ("external", gfc_match_external, ST_ATTR_DECL);
216 match ("format", gfc_match_format, ST_FORMAT);
220 match ("go to", gfc_match_goto, ST_GOTO);
224 match ("inquire", gfc_match_inquire, ST_INQUIRE);
225 match ("implicit", gfc_match_implicit, ST_IMPLICIT);
226 match ("implicit% none", gfc_match_implicit_none, ST_IMPLICIT_NONE);
227 match ("interface", gfc_match_interface, ST_INTERFACE);
228 match ("intent", gfc_match_intent, ST_ATTR_DECL);
229 match ("intrinsic", gfc_match_intrinsic, ST_ATTR_DECL);
233 match ("module% procedure% ", gfc_match_modproc, ST_MODULE_PROC);
234 match ("module", gfc_match_module, ST_MODULE);
238 match ("nullify", gfc_match_nullify, ST_NULLIFY);
239 match ("namelist", gfc_match_namelist, ST_NAMELIST);
243 match ("open", gfc_match_open, ST_OPEN);
244 match ("optional", gfc_match_optional, ST_ATTR_DECL);
248 match ("print", gfc_match_print, ST_WRITE);
249 match ("parameter", gfc_match_parameter, ST_PARAMETER);
250 match ("pause", gfc_match_pause, ST_PAUSE);
251 match ("pointer", gfc_match_pointer, ST_ATTR_DECL);
252 if (gfc_match_private (&st) == MATCH_YES)
254 match ("program", gfc_match_program, ST_PROGRAM);
255 if (gfc_match_public (&st) == MATCH_YES)
260 match ("read", gfc_match_read, ST_READ);
261 match ("return", gfc_match_return, ST_RETURN);
262 match ("rewind", gfc_match_rewind, ST_REWIND);
266 match ("sequence", gfc_match_eos, ST_SEQUENCE);
267 match ("stop", gfc_match_stop, ST_STOP);
268 match ("save", gfc_match_save, ST_ATTR_DECL);
272 match ("target", gfc_match_target, ST_ATTR_DECL);
273 match ("type", gfc_match_derived_decl, ST_DERIVED_DECL);
277 match ("use% ", gfc_match_use, ST_USE);
281 match ("write", gfc_match_write, ST_WRITE);
285 /* All else has failed, so give up. See if any of the matchers has
286 stored an error message of some sort. */
288 if (gfc_error_check () == 0)
289 gfc_error_now ("Unclassifiable statement at %C");
293 gfc_error_recovery ();
301 /* Get the next statement in free form source. */
309 gfc_gobble_whitespace ();
311 c = gfc_peek_char ();
315 /* Found a statement label? */
316 m = gfc_match_st_label (&gfc_statement_label, 0);
318 d = gfc_peek_char ();
319 if (m != MATCH_YES || !gfc_is_whitespace (d))
323 /* Skip the bad statement label. */
324 gfc_warning_now ("Ignoring bad statement label at %C");
325 c = gfc_next_char ();
331 label_locus = gfc_current_locus;
333 if (gfc_statement_label->value == 0)
335 gfc_warning_now ("Ignoring statement label of zero at %C");
336 gfc_free_st_label (gfc_statement_label);
337 gfc_statement_label = NULL;
340 gfc_gobble_whitespace ();
342 if (gfc_match_eos () == MATCH_YES)
345 ("Ignoring statement label in empty statement at %C");
346 gfc_free_st_label (gfc_statement_label);
347 gfc_statement_label = NULL;
353 return decode_statement ();
357 /* Get the next statement in fixed-form source. */
362 int label, digit_flag, i;
367 return decode_statement ();
369 /* Skip past the current label field, parsing a statement label if
370 one is there. This is a weird number parser, since the number is
371 contained within five columns and can have any kind of embedded
372 spaces. We also check for characters that make the rest of the
378 for (i = 0; i < 5; i++)
380 c = gfc_next_char_literal (0);
397 label = label * 10 + c - '0';
398 label_locus = gfc_current_locus;
402 /* Comments have already been skipped by the time we get
403 here so don't bother checking for them. */
406 gfc_buffer_error (0);
407 gfc_error ("Non-numeric character in statement label at %C");
415 gfc_warning_now ("Zero is not a valid statement label at %C");
418 /* We've found a valid statement label. */
419 gfc_statement_label = gfc_get_st_label (label);
423 /* Since this line starts a statement, it cannot be a continuation
424 of a previous statement. If we see something here besides a
425 space or zero, it must be a bad continuation line. */
427 c = gfc_next_char_literal (0);
431 if (c != ' ' && c!= '0')
433 gfc_buffer_error (0);
434 gfc_error ("Bad continuation line at %C");
438 /* Now that we've taken care of the statement label columns, we have
439 to make sure that the first nonblank character is not a '!'. If
440 it is, the rest of the line is a comment. */
444 loc = gfc_current_locus;
445 c = gfc_next_char_literal (0);
447 while (gfc_is_whitespace (c));
451 gfc_current_locus = loc;
453 if (gfc_match_eos () == MATCH_YES)
456 /* At this point, we've got a nonblank statement to parse. */
457 return decode_statement ();
461 gfc_warning ("Statement label in blank line will be " "ignored at %C");
467 /* Return the next non-ST_NONE statement to the caller. We also worry
468 about including files and the ends of include files at this stage. */
471 next_statement (void)
475 gfc_new_block = NULL;
479 gfc_statement_label = NULL;
480 gfc_buffer_error (1);
485 gfc_skip_comments ();
494 (gfc_current_form == FORM_FIXED) ? next_fixed () : next_free ();
500 gfc_buffer_error (0);
503 check_statement_label (st);
509 /****************************** Parser ***********************************/
511 /* The parser subroutines are of type 'try' that fail if the file ends
514 /* Macros that expand to case-labels for various classes of
515 statements. Start with executable statements that directly do
518 #define case_executable case ST_ALLOCATE: case ST_BACKSPACE: case ST_CALL: \
519 case ST_CLOSE: case ST_CONTINUE: case ST_DEALLOCATE: case ST_END_FILE: \
520 case ST_GOTO: case ST_INQUIRE: case ST_NULLIFY: case ST_OPEN: \
521 case ST_READ: case ST_RETURN: case ST_REWIND: case ST_SIMPLE_IF: \
522 case ST_PAUSE: case ST_STOP: case ST_WRITE: case ST_ASSIGNMENT: \
523 case ST_POINTER_ASSIGNMENT: case ST_EXIT: case ST_CYCLE: \
524 case ST_ARITHMETIC_IF: case ST_WHERE: case ST_FORALL: case ST_LABEL_ASSIGNMENT
526 /* Statements that mark other executable statements. */
528 #define case_exec_markers case ST_DO: case ST_FORALL_BLOCK: case ST_IF_BLOCK: \
529 case ST_WHERE_BLOCK: case ST_SELECT_CASE
531 /* Declaration statements */
533 #define case_decl case ST_ATTR_DECL: case ST_COMMON: case ST_DATA_DECL: \
534 case ST_EQUIVALENCE: case ST_NAMELIST: case ST_STATEMENT_FUNCTION: \
535 case ST_TYPE: case ST_INTERFACE
537 /* Block end statements. Errors associated with interchanging these
538 are detected in gfc_match_end(). */
540 #define case_end case ST_END_BLOCK_DATA: case ST_END_FUNCTION: \
541 case ST_END_PROGRAM: case ST_END_SUBROUTINE
544 /* Push a new state onto the stack. */
547 push_state (gfc_state_data * p, gfc_compile_state new_state, gfc_symbol * sym)
550 p->state = new_state;
551 p->previous = gfc_state_stack;
553 p->head = p->tail = NULL;
554 p->do_variable = NULL;
560 /* Pop the current state. */
566 gfc_state_stack = gfc_state_stack->previous;
570 /* Try to find the given state in the state stack. */
573 gfc_find_state (gfc_compile_state state)
577 for (p = gfc_state_stack; p; p = p->previous)
578 if (p->state == state)
581 return (p == NULL) ? FAILURE : SUCCESS;
585 /* Starts a new level in the statement list. */
588 new_level (gfc_code * q)
592 p = q->block = gfc_get_code ();
594 gfc_state_stack->head = gfc_state_stack->tail = p;
600 /* Add the current new_st code structure and adds it to the current
601 program unit. As a side-effect, it zeroes the new_st. */
611 p->loc = gfc_current_locus;
613 if (gfc_state_stack->head == NULL)
614 gfc_state_stack->head = p;
616 gfc_state_stack->tail->next = p;
618 while (p->next != NULL)
621 gfc_state_stack->tail = p;
629 /* Frees everything associated with the current statement. */
632 undo_new_statement (void)
634 gfc_free_statements (new_st.block);
635 gfc_free_statements (new_st.next);
636 gfc_free_statement (&new_st);
641 /* If the current statement has a statement label, make sure that it
642 is allowed to, or should have one. */
645 check_statement_label (gfc_statement st)
649 if (gfc_statement_label == NULL)
652 gfc_error ("FORMAT statement at %L does not have a statement label",
660 case ST_END_FUNCTION:
661 case ST_END_SUBROUTINE:
667 type = ST_LABEL_TARGET;
671 type = ST_LABEL_FORMAT;
674 /* Statement labels are not restricted from appearing on a
675 particular line. However, there are plenty of situations
676 where the resulting label can't be referenced. */
679 type = ST_LABEL_BAD_TARGET;
683 gfc_define_st_label (gfc_statement_label, type, &label_locus);
685 new_st.here = gfc_statement_label;
689 /* Figures out what the enclosing program unit is. This will be a
690 function, subroutine, program, block data or module. */
693 gfc_enclosing_unit (gfc_compile_state * result)
697 for (p = gfc_state_stack; p; p = p->previous)
698 if (p->state == COMP_FUNCTION || p->state == COMP_SUBROUTINE
699 || p->state == COMP_MODULE || p->state == COMP_BLOCK_DATA
700 || p->state == COMP_PROGRAM)
709 *result = COMP_PROGRAM;
714 /* Translate a statement enum to a string. */
717 gfc_ascii_statement (gfc_statement st)
723 case ST_ARITHMETIC_IF:
730 p = "attribute declaration";
760 p = "data declaration";
768 case ST_DERIVED_DECL:
769 p = "Derived type declaration";
783 case ST_END_BLOCK_DATA:
784 p = "END BLOCK DATA";
795 case ST_END_FUNCTION:
801 case ST_END_INTERFACE:
813 case ST_END_SUBROUTINE:
814 p = "END SUBROUTINE";
831 case ST_FORALL_BLOCK: /* Fall through */
850 case ST_IMPLICIT_NONE:
853 case ST_IMPLIED_ENDDO:
854 p = "implied END DO";
878 p = "MODULE PROCEDURE";
913 case ST_WHERE_BLOCK: /* Fall through */
923 case ST_POINTER_ASSIGNMENT:
924 p = "pointer assignment";
935 case ST_STATEMENT_FUNCTION:
936 p = "STATEMENT FUNCTION";
938 case ST_LABEL_ASSIGNMENT:
939 p = "LABEL ASSIGNMENT";
942 gfc_internal_error ("gfc_ascii_statement(): Bad statement code");
949 /* Return the name of a compile state. */
952 gfc_state_name (gfc_compile_state state)
964 case COMP_SUBROUTINE:
970 case COMP_BLOCK_DATA:
977 p = "a DERIVED TYPE block";
980 p = "an IF-THEN block";
986 p = "a SELECT block";
989 p = "a FORALL block";
995 p = "a contained subprogram";
999 gfc_internal_error ("gfc_state_name(): Bad state");
1006 /* Do whatever is necessary to accept the last statement. */
1009 accept_statement (gfc_statement st)
1018 case ST_IMPLICIT_NONE:
1019 gfc_set_implicit_none ();
1028 gfc_current_ns->proc_name = gfc_new_block;
1031 /* If the statement is the end of a block, lay down a special code
1032 that allows a branch to the end of the block from within the
1038 if (gfc_statement_label != NULL)
1040 new_st.op = EXEC_NOP;
1046 /* The end-of-program unit statements do not get the special
1047 marker and require a statement of some sort if they are a
1050 case ST_END_PROGRAM:
1051 case ST_END_FUNCTION:
1052 case ST_END_SUBROUTINE:
1053 if (gfc_statement_label != NULL)
1055 new_st.op = EXEC_RETURN;
1063 gfc_symbol *block_data = NULL;
1064 symbol_attribute attr;
1066 gfc_get_symbol ("_BLOCK_DATA__", gfc_current_ns, &block_data);
1067 gfc_clear_attr (&attr);
1068 attr.flavor = FL_PROCEDURE;
1069 attr.proc = PROC_UNKNOWN;
1070 attr.subroutine = 1;
1071 attr.access = ACCESS_PUBLIC;
1072 block_data->attr = attr;
1073 gfc_current_ns->proc_name = block_data;
1074 gfc_commit_symbols ();
1089 gfc_commit_symbols ();
1090 gfc_warning_check ();
1091 gfc_clear_new_st ();
1095 /* Undo anything tentative that has been built for the current
1099 reject_statement (void)
1102 gfc_undo_symbols ();
1103 gfc_clear_warning ();
1104 undo_new_statement ();
1108 /* Generic complaint about an out of order statement. We also do
1109 whatever is necessary to clean up. */
1112 unexpected_statement (gfc_statement st)
1115 gfc_error ("Unexpected %s statement at %C", gfc_ascii_statement (st));
1117 reject_statement ();
1121 /* Given the next statement seen by the matcher, make sure that it is
1122 in proper order with the last. This subroutine is initialized by
1123 calling it with an argument of ST_NONE. If there is a problem, we
1124 issue an error and return FAILURE. Otherwise we return SUCCESS.
1126 Individual parsers need to verify that the statements seen are
1127 valid before calling here, ie ENTRY statements are not allowed in
1128 INTERFACE blocks. The following diagram is taken from the standard:
1130 +---------------------------------------+
1131 | program subroutine function module |
1132 +---------------------------------------+
1134 |---------------------------------------+
1136 | +-----------+------------------+
1137 | | parameter | implicit |
1138 | +-----------+------------------+
1139 | format | | derived type |
1140 | entry | parameter | interface |
1141 | | data | specification |
1142 | | | statement func |
1143 | +-----------+------------------+
1144 | | data | executable |
1145 +--------+-----------+------------------+
1147 +---------------------------------------+
1148 | internal module/subprogram |
1149 +---------------------------------------+
1151 +---------------------------------------+
1158 { ORDER_START, ORDER_USE, ORDER_IMPLICIT_NONE, ORDER_IMPLICIT,
1159 ORDER_SPEC, ORDER_EXEC
1162 gfc_statement last_statement;
1168 verify_st_order (st_state * p, gfc_statement st)
1174 p->state = ORDER_START;
1178 if (p->state > ORDER_USE)
1180 p->state = ORDER_USE;
1183 case ST_IMPLICIT_NONE:
1184 if (p->state > ORDER_IMPLICIT_NONE)
1187 /* The '>' sign cannot be a '>=', because a FORMAT or ENTRY
1188 statement disqualifies a USE but not an IMPLICIT NONE.
1189 Duplicate IMPLICIT NONEs are caught when the implicit types
1192 p->state = ORDER_IMPLICIT_NONE;
1196 if (p->state > ORDER_IMPLICIT)
1198 p->state = ORDER_IMPLICIT;
1203 if (p->state < ORDER_IMPLICIT_NONE)
1204 p->state = ORDER_IMPLICIT_NONE;
1208 if (p->state >= ORDER_EXEC)
1210 if (p->state < ORDER_IMPLICIT)
1211 p->state = ORDER_IMPLICIT;
1215 if (p->state < ORDER_SPEC)
1216 p->state = ORDER_SPEC;
1221 case ST_DERIVED_DECL:
1223 if (p->state >= ORDER_EXEC)
1225 if (p->state < ORDER_SPEC)
1226 p->state = ORDER_SPEC;
1231 if (p->state < ORDER_EXEC)
1232 p->state = ORDER_EXEC;
1237 ("Unexpected %s statement in verify_st_order() at %C",
1238 gfc_ascii_statement (st));
1241 /* All is well, record the statement in case we need it next time. */
1242 p->where = gfc_current_locus;
1243 p->last_statement = st;
1247 gfc_error ("%s statement at %C cannot follow %s statement at %L",
1248 gfc_ascii_statement (st),
1249 gfc_ascii_statement (p->last_statement), &p->where);
1255 /* Handle an unexpected end of file. This is a show-stopper... */
1257 static void unexpected_eof (void) ATTRIBUTE_NORETURN;
1260 unexpected_eof (void)
1264 gfc_error ("Unexpected end of file in '%s'", gfc_source_file);
1266 /* Memory cleanup. Move to "second to last". */
1267 for (p = gfc_state_stack; p && p->previous && p->previous->previous;
1270 gfc_current_ns->code = (p && p->previous) ? p->head : NULL;
1277 /* Parse a derived type. */
1280 parse_derived (void)
1282 int compiling_type, seen_private, seen_sequence, seen_component, error_flag;
1289 accept_statement (ST_DERIVED_DECL);
1290 push_state (&s, COMP_DERIVED, gfc_new_block);
1292 gfc_new_block->component_access = ACCESS_PUBLIC;
1299 while (compiling_type)
1301 st = next_statement ();
1308 accept_statement (st);
1315 if (!seen_component)
1317 gfc_error ("Derived type definition at %C has no components");
1321 accept_statement (ST_END_TYPE);
1325 if (gfc_find_state (COMP_MODULE) == FAILURE)
1328 ("PRIVATE statement in TYPE at %C must be inside a MODULE");
1335 gfc_error ("PRIVATE statement at %C must precede "
1336 "structure components");
1343 gfc_error ("Duplicate PRIVATE statement at %C");
1347 s.sym->component_access = ACCESS_PRIVATE;
1348 accept_statement (ST_PRIVATE);
1355 gfc_error ("SEQUENCE statement at %C must precede "
1356 "structure components");
1361 if (gfc_current_block ()->attr.sequence)
1362 gfc_warning ("SEQUENCE attribute at %C already specified in "
1367 gfc_error ("Duplicate SEQUENCE statement at %C");
1372 gfc_add_sequence (&gfc_current_block ()->attr, NULL);
1376 unexpected_statement (st);
1381 /* Sanity checks on the structure. If the structure has the
1382 SEQUENCE attribute, then all component structures must also have
1384 if (error_flag == 0 && gfc_current_block ()->attr.sequence)
1385 for (c = gfc_current_block ()->components; c; c = c->next)
1387 if (c->ts.type == BT_DERIVED && c->ts.derived->attr.sequence == 0)
1390 ("Component %s of SEQUENCE type declared at %C does not "
1391 "have the SEQUENCE attribute", c->ts.derived->name);
1400 /* Parse an interface. We must be able to deal with the possibility
1401 of recursive interfaces. The parse_spec() subroutine is mutually
1402 recursive with parse_interface(). */
1404 static gfc_statement parse_spec (gfc_statement);
1407 parse_interface (void)
1409 gfc_compile_state new_state, current_state;
1410 gfc_symbol *prog_unit, *sym;
1411 gfc_interface_info save;
1412 gfc_state_data s1, s2;
1415 accept_statement (ST_INTERFACE);
1417 current_interface.ns = gfc_current_ns;
1418 save = current_interface;
1420 sym = (current_interface.type == INTERFACE_GENERIC
1421 || current_interface.type == INTERFACE_USER_OP) ? gfc_new_block : NULL;
1423 push_state (&s1, COMP_INTERFACE, sym);
1424 current_state = COMP_NONE;
1427 gfc_current_ns = gfc_get_namespace (current_interface.ns);
1429 st = next_statement ();
1436 new_state = COMP_SUBROUTINE;
1437 gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
1438 gfc_new_block->formal, NULL);
1442 new_state = COMP_FUNCTION;
1443 gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
1444 gfc_new_block->formal, NULL);
1447 case ST_MODULE_PROC: /* The module procedure matcher makes
1448 sure the context is correct. */
1449 accept_statement (st);
1450 gfc_free_namespace (gfc_current_ns);
1453 case ST_END_INTERFACE:
1454 gfc_free_namespace (gfc_current_ns);
1455 gfc_current_ns = current_interface.ns;
1459 gfc_error ("Unexpected %s statement in INTERFACE block at %C",
1460 gfc_ascii_statement (st));
1461 reject_statement ();
1462 gfc_free_namespace (gfc_current_ns);
1467 /* Make sure that a generic interface has only subroutines or
1468 functions and that the generic name has the right attribute. */
1469 if (current_interface.type == INTERFACE_GENERIC)
1471 if (current_state == COMP_NONE)
1473 if (new_state == COMP_FUNCTION)
1474 gfc_add_function (&sym->attr, NULL);
1475 if (new_state == COMP_SUBROUTINE)
1476 gfc_add_subroutine (&sym->attr, NULL);
1478 current_state = new_state;
1482 if (new_state != current_state)
1484 if (new_state == COMP_SUBROUTINE)
1486 ("SUBROUTINE at %C does not belong in a generic function "
1489 if (new_state == COMP_FUNCTION)
1491 ("FUNCTION at %C does not belong in a generic subroutine "
1497 push_state (&s2, new_state, gfc_new_block);
1498 accept_statement (st);
1499 prog_unit = gfc_new_block;
1500 prog_unit->formal_ns = gfc_current_ns;
1503 /* Read data declaration statements. */
1504 st = parse_spec (ST_NONE);
1506 if (st != ST_END_SUBROUTINE && st != ST_END_FUNCTION)
1508 gfc_error ("Unexpected %s statement at %C in INTERFACE body",
1509 gfc_ascii_statement (st));
1510 reject_statement ();
1514 current_interface = save;
1515 gfc_add_interface (prog_unit);
1525 /* Parse a set of specification statements. Returns the statement
1526 that doesn't fit. */
1528 static gfc_statement
1529 parse_spec (gfc_statement st)
1533 verify_st_order (&ss, ST_NONE);
1535 st = next_statement ();
1545 case ST_DATA: /* Not allowed in interfaces */
1546 if (gfc_current_state () == COMP_INTERFACE)
1552 case ST_IMPLICIT_NONE:
1557 case ST_DERIVED_DECL:
1559 if (verify_st_order (&ss, st) == FAILURE)
1561 reject_statement ();
1562 st = next_statement ();
1572 case ST_DERIVED_DECL:
1578 if (gfc_current_state () != COMP_MODULE)
1580 gfc_error ("%s statement must appear in a MODULE",
1581 gfc_ascii_statement (st));
1585 if (gfc_current_ns->default_access != ACCESS_UNKNOWN)
1587 gfc_error ("%s statement at %C follows another accessibility "
1588 "specification", gfc_ascii_statement (st));
1592 gfc_current_ns->default_access = (st == ST_PUBLIC)
1593 ? ACCESS_PUBLIC : ACCESS_PRIVATE;
1601 accept_statement (st);
1602 st = next_statement ();
1613 /* Parse a WHERE block, (not a simple WHERE statement). */
1616 parse_where_block (void)
1618 int seen_empty_else;
1623 accept_statement (ST_WHERE_BLOCK);
1624 top = gfc_state_stack->tail;
1626 push_state (&s, COMP_WHERE, gfc_new_block);
1628 d = add_statement ();
1629 d->expr = top->expr;
1635 seen_empty_else = 0;
1639 st = next_statement ();
1645 case ST_WHERE_BLOCK:
1646 parse_where_block ();
1651 accept_statement (st);
1655 if (seen_empty_else)
1658 ("ELSEWHERE statement at %C follows previous unmasked "
1663 if (new_st.expr == NULL)
1664 seen_empty_else = 1;
1666 d = new_level (gfc_state_stack->head);
1668 d->expr = new_st.expr;
1670 accept_statement (st);
1675 accept_statement (st);
1679 gfc_error ("Unexpected %s statement in WHERE block at %C",
1680 gfc_ascii_statement (st));
1681 reject_statement ();
1686 while (st != ST_END_WHERE);
1692 /* Parse a FORALL block (not a simple FORALL statement). */
1695 parse_forall_block (void)
1701 accept_statement (ST_FORALL_BLOCK);
1702 top = gfc_state_stack->tail;
1704 push_state (&s, COMP_FORALL, gfc_new_block);
1706 d = add_statement ();
1707 d->op = EXEC_FORALL;
1712 st = next_statement ();
1717 case ST_POINTER_ASSIGNMENT:
1720 accept_statement (st);
1723 case ST_WHERE_BLOCK:
1724 parse_where_block ();
1727 case ST_FORALL_BLOCK:
1728 parse_forall_block ();
1732 accept_statement (st);
1739 gfc_error ("Unexpected %s statement in FORALL block at %C",
1740 gfc_ascii_statement (st));
1742 reject_statement ();
1746 while (st != ST_END_FORALL);
1752 static gfc_statement parse_executable (gfc_statement);
1754 /* parse the statements of an IF-THEN-ELSEIF-ELSE-ENDIF block. */
1757 parse_if_block (void)
1766 accept_statement (ST_IF_BLOCK);
1768 top = gfc_state_stack->tail;
1769 push_state (&s, COMP_IF, gfc_new_block);
1771 new_st.op = EXEC_IF;
1772 d = add_statement ();
1774 d->expr = top->expr;
1780 st = parse_executable (ST_NONE);
1791 ("ELSE IF statement at %C cannot follow ELSE statement at %L",
1794 reject_statement ();
1798 d = new_level (gfc_state_stack->head);
1800 d->expr = new_st.expr;
1802 accept_statement (st);
1809 gfc_error ("Duplicate ELSE statements at %L and %C",
1811 reject_statement ();
1816 else_locus = gfc_current_locus;
1818 d = new_level (gfc_state_stack->head);
1821 accept_statement (st);
1829 unexpected_statement (st);
1833 while (st != ST_ENDIF);
1836 accept_statement (st);
1840 /* Parse a SELECT block. */
1843 parse_select_block (void)
1849 accept_statement (ST_SELECT_CASE);
1851 cp = gfc_state_stack->tail;
1852 push_state (&s, COMP_SELECT, gfc_new_block);
1854 /* Make sure that the next statement is a CASE or END SELECT. */
1857 st = next_statement ();
1860 if (st == ST_END_SELECT)
1862 /* Empty SELECT CASE is OK. */
1863 accept_statement (st);
1871 ("Expected a CASE or END SELECT statement following SELECT CASE "
1874 reject_statement ();
1877 /* At this point, we're got a nonempty select block. */
1878 cp = new_level (cp);
1881 accept_statement (st);
1885 st = parse_executable (ST_NONE);
1892 cp = new_level (gfc_state_stack->head);
1894 gfc_clear_new_st ();
1896 accept_statement (st);
1902 /* Can't have an executable statement because of
1903 parse_executable(). */
1905 unexpected_statement (st);
1909 while (st != ST_END_SELECT);
1912 accept_statement (st);
1916 /* Given a symbol, make sure it is not an iteration variable for a DO
1917 statement. This subroutine is called when the symbol is seen in a
1918 context that causes it to become redefined. If the symbol is an
1919 iterator, we generate an error message and return nonzero. */
1922 gfc_check_do_variable (gfc_symtree *st)
1926 for (s=gfc_state_stack; s; s = s->previous)
1927 if (s->do_variable == st)
1929 gfc_error_now("Variable '%s' at %C cannot be redefined inside "
1930 "loop beginning at %L", st->name, &s->head->loc);
1938 /* Checks to see if the current statement label closes an enddo.
1939 Returns 0 if not, 1 if closes an ENDDO correctly, or 2 (and issues
1940 an error) if it incorrectly closes an ENDDO. */
1943 check_do_closure (void)
1947 if (gfc_statement_label == NULL)
1950 for (p = gfc_state_stack; p; p = p->previous)
1951 if (p->state == COMP_DO)
1955 return 0; /* No loops to close */
1957 if (p->ext.end_do_label == gfc_statement_label)
1960 if (p == gfc_state_stack)
1964 ("End of nonblock DO statement at %C is within another block");
1968 /* At this point, the label doesn't terminate the innermost loop.
1969 Make sure it doesn't terminate another one. */
1970 for (; p; p = p->previous)
1971 if (p->state == COMP_DO && p->ext.end_do_label == gfc_statement_label)
1973 gfc_error ("End of nonblock DO statement at %C is interwoven "
1974 "with another DO loop");
1982 /* Parse a DO loop. Note that the ST_CYCLE and ST_EXIT statements are
1983 handled inside of parse_executable(), because they aren't really
1987 parse_do_block (void)
1994 s.ext.end_do_label = new_st.label;
1996 if (new_st.ext.iterator != NULL)
1997 stree = new_st.ext.iterator->var->symtree;
2001 accept_statement (ST_DO);
2003 top = gfc_state_stack->tail;
2004 push_state (&s, COMP_DO, gfc_new_block);
2006 s.do_variable = stree;
2008 top->block = new_level (top);
2009 top->block->op = EXEC_DO;
2012 st = parse_executable (ST_NONE);
2020 if (s.ext.end_do_label != NULL
2021 && s.ext.end_do_label != gfc_statement_label)
2023 ("Statement label in ENDDO at %C doesn't match DO label");
2026 case ST_IMPLIED_ENDDO:
2030 unexpected_statement (st);
2035 accept_statement (st);
2039 /* Accept a series of executable statements. We return the first
2040 statement that doesn't fit to the caller. Any block statements are
2041 passed on to the correct handler, which usually passes the buck
2044 static gfc_statement
2045 parse_executable (gfc_statement st)
2050 st = next_statement ();
2052 for (;; st = next_statement ())
2055 close_flag = check_do_closure ();
2060 case ST_END_PROGRAM:
2063 case ST_END_FUNCTION:
2067 case ST_END_SUBROUTINE:
2072 case ST_SELECT_CASE:
2074 ("%s statement at %C cannot terminate a non-block DO loop",
2075 gfc_ascii_statement (st));
2091 accept_statement (st);
2092 if (close_flag == 1)
2093 return ST_IMPLIED_ENDDO;
2100 case ST_SELECT_CASE:
2101 parse_select_block ();
2106 if (check_do_closure () == 1)
2107 return ST_IMPLIED_ENDDO;
2110 case ST_WHERE_BLOCK:
2111 parse_where_block ();
2114 case ST_FORALL_BLOCK:
2115 parse_forall_block ();
2129 /* Parse a series of contained program units. */
2131 static void parse_progunit (gfc_statement);
2134 /* Fix the symbols for sibling functions. These are incorrectly added to
2135 the child namespace as the parser didn't know about this procedure. */
2138 gfc_fixup_sibling_symbols (gfc_symbol * sym, gfc_namespace * siblings)
2142 gfc_symbol *old_sym;
2144 sym->attr.referenced = 1;
2145 for (ns = siblings; ns; ns = ns->sibling)
2147 gfc_find_sym_tree (sym->name, ns, 0, &st);
2151 old_sym = st->n.sym;
2152 if ((old_sym->attr.flavor == FL_PROCEDURE
2153 || old_sym->ts.type == BT_UNKNOWN)
2154 && old_sym->ns == ns
2155 && ! old_sym->attr.contained)
2157 /* Replace it with the symbol from the parent namespace. */
2161 /* Free the old (local) symbol. */
2163 if (old_sym->refs == 0)
2164 gfc_free_symbol (old_sym);
2167 /* Do the same for any contined procedures. */
2168 gfc_fixup_sibling_symbols (sym, ns->contained);
2173 parse_contained (int module)
2175 gfc_namespace *ns, *parent_ns;
2176 gfc_state_data s1, s2;
2181 push_state (&s1, COMP_CONTAINS, NULL);
2182 parent_ns = gfc_current_ns;
2186 gfc_current_ns = gfc_get_namespace (parent_ns);
2188 gfc_current_ns->sibling = parent_ns->contained;
2189 parent_ns->contained = gfc_current_ns;
2191 st = next_statement ();
2200 accept_statement (st);
2203 (st == ST_FUNCTION) ? COMP_FUNCTION : COMP_SUBROUTINE,
2206 /* For internal procedures, create/update the symbol in the
2207 parent namespace. */
2211 if (gfc_get_symbol (gfc_new_block->name, parent_ns, &sym))
2213 ("Contained procedure '%s' at %C is already ambiguous",
2214 gfc_new_block->name);
2217 if (gfc_add_procedure (&sym->attr, PROC_INTERNAL,
2218 &gfc_new_block->declared_at) ==
2221 if (st == ST_FUNCTION)
2222 gfc_add_function (&sym->attr,
2223 &gfc_new_block->declared_at);
2225 gfc_add_subroutine (&sym->attr,
2226 &gfc_new_block->declared_at);
2230 gfc_commit_symbols ();
2233 sym = gfc_new_block;
2235 /* Mark this as a contained function, so it isn't replaced
2236 by other module functions. */
2237 sym->attr.contained = 1;
2238 sym->attr.referenced = 1;
2240 parse_progunit (ST_NONE);
2242 /* Fix up any sibling functions that refer to this one. */
2243 gfc_fixup_sibling_symbols (sym, gfc_current_ns);
2244 /* Or refer to any of its alternate entry points. */
2245 for (el = gfc_current_ns->entries; el; el = el->next)
2246 gfc_fixup_sibling_symbols (el->sym, gfc_current_ns);
2248 gfc_current_ns->code = s2.head;
2249 gfc_current_ns = parent_ns;
2254 /* These statements are associated with the end of the host
2256 case ST_END_FUNCTION:
2258 case ST_END_PROGRAM:
2259 case ST_END_SUBROUTINE:
2260 accept_statement (st);
2264 gfc_error ("Unexpected %s statement in CONTAINS section at %C",
2265 gfc_ascii_statement (st));
2266 reject_statement ();
2270 while (st != ST_END_FUNCTION && st != ST_END_SUBROUTINE
2271 && st != ST_END_MODULE && st != ST_END_PROGRAM);
2273 /* The first namespace in the list is guaranteed to not have
2274 anything (worthwhile) in it. */
2276 gfc_current_ns = parent_ns;
2278 ns = gfc_current_ns->contained;
2279 gfc_current_ns->contained = ns->sibling;
2280 gfc_free_namespace (ns);
2286 /* Parse a PROGRAM, SUBROUTINE or FUNCTION unit. */
2289 parse_progunit (gfc_statement st)
2294 st = parse_spec (st);
2304 accept_statement (st);
2314 st = parse_executable (st);
2325 accept_statement (st);
2332 unexpected_statement (st);
2333 reject_statement ();
2334 st = next_statement ();
2340 for (p = gfc_state_stack; p; p = p->previous)
2341 if (p->state == COMP_CONTAINS)
2344 if (gfc_find_state (COMP_MODULE) == SUCCESS)
2349 gfc_error ("CONTAINS statement at %C is already in a contained "
2351 st = next_statement ();
2355 parse_contained (0);
2358 gfc_current_ns->code = gfc_state_stack->head;
2362 /* Come here to complain about a global symbol already in use as
2366 global_used (gfc_gsymbol *sym, locus *where)
2371 where = &gfc_current_locus;
2381 case GSYM_SUBROUTINE:
2382 name = "SUBROUTINE";
2387 case GSYM_BLOCK_DATA:
2388 name = "BLOCK DATA";
2394 gfc_internal_error ("gfc_gsymbol_type(): Bad type");
2398 gfc_error("Global name '%s' at %L is already being used as a %s at %L",
2399 gfc_new_block->name, where, name, &sym->where);
2403 /* Parse a block data program unit. */
2406 parse_block_data (void)
2409 static locus blank_locus;
2410 static int blank_block=0;
2413 if (gfc_new_block == NULL)
2416 gfc_error ("Blank BLOCK DATA at %C conflicts with "
2417 "prior BLOCK DATA at %L", &blank_locus);
2421 blank_locus = gfc_current_locus;
2426 s = gfc_get_gsymbol (gfc_new_block->name);
2427 if (s->type != GSYM_UNKNOWN)
2428 global_used(s, NULL);
2431 s->type = GSYM_BLOCK_DATA;
2432 s->where = gfc_current_locus;
2436 st = parse_spec (ST_NONE);
2438 while (st != ST_END_BLOCK_DATA)
2440 gfc_error ("Unexpected %s statement in BLOCK DATA at %C",
2441 gfc_ascii_statement (st));
2442 reject_statement ();
2443 st = next_statement ();
2448 /* Parse a module subprogram. */
2456 s = gfc_get_gsymbol (gfc_new_block->name);
2457 if (s->type != GSYM_UNKNOWN)
2458 global_used(s, NULL);
2461 s->type = GSYM_MODULE;
2462 s->where = gfc_current_locus;
2465 st = parse_spec (ST_NONE);
2474 parse_contained (1);
2478 accept_statement (st);
2482 gfc_error ("Unexpected %s statement in MODULE at %C",
2483 gfc_ascii_statement (st));
2485 reject_statement ();
2486 st = next_statement ();
2492 /* Add a procedure name to the global symbol table. */
2495 add_global_procedure (int sub)
2499 s = gfc_get_gsymbol(gfc_new_block->name);
2501 if (s->type != GSYM_UNKNOWN)
2502 global_used(s, NULL);
2505 s->type = sub ? GSYM_SUBROUTINE : GSYM_FUNCTION;
2506 s->where = gfc_current_locus;
2511 /* Add a program to the global symbol table. */
2514 add_global_program (void)
2518 if (gfc_new_block == NULL)
2520 s = gfc_get_gsymbol (gfc_new_block->name);
2522 if (s->type != GSYM_UNKNOWN)
2523 global_used(s, NULL);
2526 s->type = GSYM_PROGRAM;
2527 s->where = gfc_current_locus;
2532 /* Top level parser. */
2535 gfc_parse_file (void)
2537 int seen_program, errors_before, errors;
2538 gfc_state_data top, s;
2542 top.state = COMP_NONE;
2544 top.previous = NULL;
2545 top.head = top.tail = NULL;
2546 top.do_variable = NULL;
2548 gfc_state_stack = ⊤
2550 gfc_clear_new_st ();
2552 gfc_statement_label = NULL;
2555 return FAILURE; /* Come here on unexpected EOF */
2561 st = next_statement ();
2570 goto duplicate_main;
2572 prog_locus = gfc_current_locus;
2574 push_state (&s, COMP_PROGRAM, gfc_new_block);
2575 accept_statement (st);
2576 add_global_program ();
2577 parse_progunit (ST_NONE);
2581 add_global_procedure (1);
2582 push_state (&s, COMP_SUBROUTINE, gfc_new_block);
2583 accept_statement (st);
2584 parse_progunit (ST_NONE);
2588 add_global_procedure (0);
2589 push_state (&s, COMP_FUNCTION, gfc_new_block);
2590 accept_statement (st);
2591 parse_progunit (ST_NONE);
2595 push_state (&s, COMP_BLOCK_DATA, gfc_new_block);
2596 accept_statement (st);
2597 parse_block_data ();
2601 push_state (&s, COMP_MODULE, gfc_new_block);
2602 accept_statement (st);
2604 gfc_get_errors (NULL, &errors_before);
2608 /* Anything else starts a nameless main program block. */
2611 goto duplicate_main;
2613 prog_locus = gfc_current_locus;
2615 push_state (&s, COMP_PROGRAM, gfc_new_block);
2616 parse_progunit (st);
2620 gfc_current_ns->code = s.head;
2622 gfc_resolve (gfc_current_ns);
2624 /* Dump the parse tree if requested. */
2625 if (gfc_option.verbose)
2626 gfc_show_namespace (gfc_current_ns);
2628 gfc_get_errors (NULL, &errors);
2629 if (s.state == COMP_MODULE)
2631 gfc_dump_module (s.sym->name, errors_before == errors);
2632 if (errors == 0 && ! gfc_option.flag_no_backend)
2633 gfc_generate_module_code (gfc_current_ns);
2637 if (errors == 0 && ! gfc_option.flag_no_backend)
2638 gfc_generate_code (gfc_current_ns);
2649 /* If we see a duplicate main program, shut down. If the second
2650 instance is an implied main program, ie data decls or executable
2651 statements, we're in for lots of errors. */
2652 gfc_error ("Two main PROGRAMs at %L and %C", &prog_locus);
2653 reject_statement ();