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;
559 /* Pop the current state. */
565 gfc_state_stack = gfc_state_stack->previous;
569 /* Try to find the given state in the state stack. */
572 gfc_find_state (gfc_compile_state state)
576 for (p = gfc_state_stack; p; p = p->previous)
577 if (p->state == state)
580 return (p == NULL) ? FAILURE : SUCCESS;
584 /* Starts a new level in the statement list. */
587 new_level (gfc_code * q)
591 p = q->block = gfc_get_code ();
593 gfc_state_stack->head = gfc_state_stack->tail = p;
599 /* Add the current new_st code structure and adds it to the current
600 program unit. As a side-effect, it zeroes the new_st. */
610 p->loc = gfc_current_locus;
612 if (gfc_state_stack->head == NULL)
613 gfc_state_stack->head = p;
615 gfc_state_stack->tail->next = p;
617 while (p->next != NULL)
620 gfc_state_stack->tail = p;
628 /* Frees everything associated with the current statement. */
631 undo_new_statement (void)
633 gfc_free_statements (new_st.block);
634 gfc_free_statements (new_st.next);
635 gfc_free_statement (&new_st);
640 /* If the current statement has a statement label, make sure that it
641 is allowed to, or should have one. */
644 check_statement_label (gfc_statement st)
648 if (gfc_statement_label == NULL)
651 gfc_error ("FORMAT statement at %L does not have a statement label",
659 case ST_END_FUNCTION:
660 case ST_END_SUBROUTINE:
666 type = ST_LABEL_TARGET;
670 type = ST_LABEL_FORMAT;
673 /* Statement labels are not restricted from appearing on a
674 particular line. However, there are plenty of situations
675 where the resulting label can't be referenced. */
678 type = ST_LABEL_BAD_TARGET;
682 gfc_define_st_label (gfc_statement_label, type, &label_locus);
684 new_st.here = gfc_statement_label;
688 /* Figures out what the enclosing program unit is. This will be a
689 function, subroutine, program, block data or module. */
692 gfc_enclosing_unit (gfc_compile_state * result)
696 for (p = gfc_state_stack; p; p = p->previous)
697 if (p->state == COMP_FUNCTION || p->state == COMP_SUBROUTINE
698 || p->state == COMP_MODULE || p->state == COMP_BLOCK_DATA
699 || p->state == COMP_PROGRAM)
708 *result = COMP_PROGRAM;
713 /* Translate a statement enum to a string. */
716 gfc_ascii_statement (gfc_statement st)
722 case ST_ARITHMETIC_IF:
729 p = "attribute declaration";
759 p = "data declaration";
767 case ST_DERIVED_DECL:
768 p = "Derived type declaration";
782 case ST_END_BLOCK_DATA:
783 p = "END BLOCK DATA";
794 case ST_END_FUNCTION:
800 case ST_END_INTERFACE:
812 case ST_END_SUBROUTINE:
813 p = "END SUBROUTINE";
830 case ST_FORALL_BLOCK: /* Fall through */
849 case ST_IMPLICIT_NONE:
852 case ST_IMPLIED_ENDDO:
853 p = "implied END DO";
877 p = "MODULE PROCEDURE";
912 case ST_WHERE_BLOCK: /* Fall through */
922 case ST_POINTER_ASSIGNMENT:
923 p = "pointer assignment";
934 case ST_STATEMENT_FUNCTION:
935 p = "STATEMENT FUNCTION";
937 case ST_LABEL_ASSIGNMENT:
938 p = "LABEL ASSIGNMENT";
941 gfc_internal_error ("gfc_ascii_statement(): Bad statement code");
948 /* Return the name of a compile state. */
951 gfc_state_name (gfc_compile_state state)
963 case COMP_SUBROUTINE:
969 case COMP_BLOCK_DATA:
976 p = "a DERIVED TYPE block";
979 p = "an IF-THEN block";
985 p = "a SELECT block";
988 p = "a FORALL block";
994 p = "a contained subprogram";
998 gfc_internal_error ("gfc_state_name(): Bad state");
1005 /* Do whatever is necessary to accept the last statement. */
1008 accept_statement (gfc_statement st)
1017 case ST_IMPLICIT_NONE:
1018 gfc_set_implicit_none ();
1027 gfc_current_ns->proc_name = gfc_new_block;
1030 /* If the statement is the end of a block, lay down a special code
1031 that allows a branch to the end of the block from within the
1037 if (gfc_statement_label != NULL)
1039 new_st.op = EXEC_NOP;
1045 /* The end-of-program unit statements do not get the special
1046 marker and require a statement of some sort if they are a
1049 case ST_END_PROGRAM:
1050 case ST_END_FUNCTION:
1051 case ST_END_SUBROUTINE:
1052 if (gfc_statement_label != NULL)
1054 new_st.op = EXEC_RETURN;
1062 gfc_symbol *block_data = NULL;
1063 symbol_attribute attr;
1065 gfc_get_symbol ("_BLOCK_DATA__", gfc_current_ns, &block_data);
1066 gfc_clear_attr (&attr);
1067 attr.flavor = FL_PROCEDURE;
1068 attr.proc = PROC_UNKNOWN;
1069 attr.subroutine = 1;
1070 attr.access = ACCESS_PUBLIC;
1071 block_data->attr = attr;
1072 gfc_current_ns->proc_name = block_data;
1073 gfc_commit_symbols ();
1087 gfc_commit_symbols ();
1088 gfc_warning_check ();
1089 gfc_clear_new_st ();
1093 /* Undo anything tentative that has been built for the current
1097 reject_statement (void)
1100 gfc_undo_symbols ();
1101 gfc_clear_warning ();
1102 undo_new_statement ();
1106 /* Generic complaint about an out of order statement. We also do
1107 whatever is necessary to clean up. */
1110 unexpected_statement (gfc_statement st)
1113 gfc_error ("Unexpected %s statement at %C", gfc_ascii_statement (st));
1115 reject_statement ();
1119 /* Given the next statement seen by the matcher, make sure that it is
1120 in proper order with the last. This subroutine is initialized by
1121 calling it with an argument of ST_NONE. If there is a problem, we
1122 issue an error and return FAILURE. Otherwise we return SUCCESS.
1124 Individual parsers need to verify that the statements seen are
1125 valid before calling here, ie ENTRY statements are not allowed in
1126 INTERFACE blocks. The following diagram is taken from the standard:
1128 +---------------------------------------+
1129 | program subroutine function module |
1130 +---------------------------------------+
1132 |---------------------------------------+
1134 | +-----------+------------------+
1135 | | parameter | implicit |
1136 | +-----------+------------------+
1137 | format | | derived type |
1138 | entry | parameter | interface |
1139 | | data | specification |
1140 | | | statement func |
1141 | +-----------+------------------+
1142 | | data | executable |
1143 +--------+-----------+------------------+
1145 +---------------------------------------+
1146 | internal module/subprogram |
1147 +---------------------------------------+
1149 +---------------------------------------+
1156 { ORDER_START, ORDER_USE, ORDER_IMPLICIT_NONE, ORDER_IMPLICIT,
1157 ORDER_SPEC, ORDER_EXEC
1160 gfc_statement last_statement;
1166 verify_st_order (st_state * p, gfc_statement st)
1172 p->state = ORDER_START;
1176 if (p->state > ORDER_USE)
1178 p->state = ORDER_USE;
1181 case ST_IMPLICIT_NONE:
1182 if (p->state > ORDER_IMPLICIT_NONE)
1185 /* The '>' sign cannot be a '>=', because a FORMAT or ENTRY
1186 statement disqualifies a USE but not an IMPLICIT NONE.
1187 Duplicate IMPLICIT NONEs are caught when the implicit types
1190 p->state = ORDER_IMPLICIT_NONE;
1194 if (p->state > ORDER_IMPLICIT)
1196 p->state = ORDER_IMPLICIT;
1201 if (p->state < ORDER_IMPLICIT_NONE)
1202 p->state = ORDER_IMPLICIT_NONE;
1206 if (p->state >= ORDER_EXEC)
1208 if (p->state < ORDER_IMPLICIT)
1209 p->state = ORDER_IMPLICIT;
1213 if (p->state < ORDER_SPEC)
1214 p->state = ORDER_SPEC;
1219 case ST_DERIVED_DECL:
1221 if (p->state >= ORDER_EXEC)
1223 if (p->state < ORDER_SPEC)
1224 p->state = ORDER_SPEC;
1229 if (p->state < ORDER_EXEC)
1230 p->state = ORDER_EXEC;
1235 ("Unexpected %s statement in verify_st_order() at %C",
1236 gfc_ascii_statement (st));
1239 /* All is well, record the statement in case we need it next time. */
1240 p->where = gfc_current_locus;
1241 p->last_statement = st;
1245 gfc_error ("%s statement at %C cannot follow %s statement at %L",
1246 gfc_ascii_statement (st),
1247 gfc_ascii_statement (p->last_statement), &p->where);
1253 /* Handle an unexpected end of file. This is a show-stopper... */
1255 static void unexpected_eof (void) ATTRIBUTE_NORETURN;
1258 unexpected_eof (void)
1262 gfc_error ("Unexpected end of file in '%s'", gfc_source_file);
1264 /* Memory cleanup. Move to "second to last". */
1265 for (p = gfc_state_stack; p && p->previous && p->previous->previous;
1268 gfc_current_ns->code = (p && p->previous) ? p->head : NULL;
1275 /* Parse a derived type. */
1278 parse_derived (void)
1280 int compiling_type, seen_private, seen_sequence, seen_component, error_flag;
1287 accept_statement (ST_DERIVED_DECL);
1288 push_state (&s, COMP_DERIVED, gfc_new_block);
1290 gfc_new_block->component_access = ACCESS_PUBLIC;
1297 while (compiling_type)
1299 st = next_statement ();
1306 accept_statement (st);
1313 if (!seen_component)
1315 gfc_error ("Derived type definition at %C has no components");
1319 accept_statement (ST_END_TYPE);
1323 if (gfc_find_state (COMP_MODULE) == FAILURE)
1326 ("PRIVATE statement in TYPE at %C must be inside a MODULE");
1333 gfc_error ("PRIVATE statement at %C must precede "
1334 "structure components");
1341 gfc_error ("Duplicate PRIVATE statement at %C");
1345 s.sym->component_access = ACCESS_PRIVATE;
1346 accept_statement (ST_PRIVATE);
1353 gfc_error ("SEQUENCE statement at %C must precede "
1354 "structure components");
1359 if (gfc_current_block ()->attr.sequence)
1360 gfc_warning ("SEQUENCE attribute at %C already specified in "
1365 gfc_error ("Duplicate SEQUENCE statement at %C");
1370 gfc_add_sequence (&gfc_current_block ()->attr, NULL);
1374 unexpected_statement (st);
1379 /* Sanity checks on the structure. If the structure has the
1380 SEQUENCE attribute, then all component structures must also have
1382 if (error_flag == 0 && gfc_current_block ()->attr.sequence)
1383 for (c = gfc_current_block ()->components; c; c = c->next)
1385 if (c->ts.type == BT_DERIVED && c->ts.derived->attr.sequence == 0)
1388 ("Component %s of SEQUENCE type declared at %C does not "
1389 "have the SEQUENCE attribute", c->ts.derived->name);
1398 /* Parse an interface. We must be able to deal with the possibility
1399 of recursive interfaces. The parse_spec() subroutine is mutually
1400 recursive with parse_interface(). */
1402 static gfc_statement parse_spec (gfc_statement);
1405 parse_interface (void)
1407 gfc_compile_state new_state, current_state;
1408 gfc_symbol *prog_unit, *sym;
1409 gfc_interface_info save;
1410 gfc_state_data s1, s2;
1413 accept_statement (ST_INTERFACE);
1415 current_interface.ns = gfc_current_ns;
1416 save = current_interface;
1418 sym = (current_interface.type == INTERFACE_GENERIC
1419 || current_interface.type == INTERFACE_USER_OP) ? gfc_new_block : NULL;
1421 push_state (&s1, COMP_INTERFACE, sym);
1422 current_state = COMP_NONE;
1425 gfc_current_ns = gfc_get_namespace (current_interface.ns);
1427 st = next_statement ();
1434 new_state = COMP_SUBROUTINE;
1435 gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
1436 gfc_new_block->formal, NULL);
1440 new_state = COMP_FUNCTION;
1441 gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
1442 gfc_new_block->formal, NULL);
1445 case ST_MODULE_PROC: /* The module procedure matcher makes
1446 sure the context is correct. */
1447 accept_statement (st);
1448 gfc_free_namespace (gfc_current_ns);
1451 case ST_END_INTERFACE:
1452 gfc_free_namespace (gfc_current_ns);
1453 gfc_current_ns = current_interface.ns;
1457 gfc_error ("Unexpected %s statement in INTERFACE block at %C",
1458 gfc_ascii_statement (st));
1459 reject_statement ();
1460 gfc_free_namespace (gfc_current_ns);
1465 /* Make sure that a generic interface has only subroutines or
1466 functions and that the generic name has the right attribute. */
1467 if (current_interface.type == INTERFACE_GENERIC)
1469 if (current_state == COMP_NONE)
1471 if (new_state == COMP_FUNCTION)
1472 gfc_add_function (&sym->attr, NULL);
1473 if (new_state == COMP_SUBROUTINE)
1474 gfc_add_subroutine (&sym->attr, NULL);
1476 current_state = new_state;
1480 if (new_state != current_state)
1482 if (new_state == COMP_SUBROUTINE)
1484 ("SUBROUTINE at %C does not belong in a generic function "
1487 if (new_state == COMP_FUNCTION)
1489 ("FUNCTION at %C does not belong in a generic subroutine "
1495 push_state (&s2, new_state, gfc_new_block);
1496 accept_statement (st);
1497 prog_unit = gfc_new_block;
1498 prog_unit->formal_ns = gfc_current_ns;
1501 /* Read data declaration statements. */
1502 st = parse_spec (ST_NONE);
1504 if (st != ST_END_SUBROUTINE && st != ST_END_FUNCTION)
1506 gfc_error ("Unexpected %s statement at %C in INTERFACE body",
1507 gfc_ascii_statement (st));
1508 reject_statement ();
1512 current_interface = save;
1513 gfc_add_interface (prog_unit);
1523 /* Parse a set of specification statements. Returns the statement
1524 that doesn't fit. */
1526 static gfc_statement
1527 parse_spec (gfc_statement st)
1531 verify_st_order (&ss, ST_NONE);
1533 st = next_statement ();
1543 case ST_DATA: /* Not allowed in interfaces */
1544 if (gfc_current_state () == COMP_INTERFACE)
1550 case ST_IMPLICIT_NONE:
1555 case ST_DERIVED_DECL:
1557 if (verify_st_order (&ss, st) == FAILURE)
1559 reject_statement ();
1560 st = next_statement ();
1570 case ST_DERIVED_DECL:
1576 if (gfc_current_state () != COMP_MODULE)
1578 gfc_error ("%s statement must appear in a MODULE",
1579 gfc_ascii_statement (st));
1583 if (gfc_current_ns->default_access != ACCESS_UNKNOWN)
1585 gfc_error ("%s statement at %C follows another accessibility "
1586 "specification", gfc_ascii_statement (st));
1590 gfc_current_ns->default_access = (st == ST_PUBLIC)
1591 ? ACCESS_PUBLIC : ACCESS_PRIVATE;
1599 accept_statement (st);
1600 st = next_statement ();
1611 /* Parse a WHERE block, (not a simple WHERE statement). */
1614 parse_where_block (void)
1616 int seen_empty_else;
1621 accept_statement (ST_WHERE_BLOCK);
1622 top = gfc_state_stack->tail;
1624 push_state (&s, COMP_WHERE, gfc_new_block);
1626 d = add_statement ();
1627 d->expr = top->expr;
1633 seen_empty_else = 0;
1637 st = next_statement ();
1643 case ST_WHERE_BLOCK:
1644 parse_where_block ();
1649 accept_statement (st);
1653 if (seen_empty_else)
1656 ("ELSEWHERE statement at %C follows previous unmasked "
1661 if (new_st.expr == NULL)
1662 seen_empty_else = 1;
1664 d = new_level (gfc_state_stack->head);
1666 d->expr = new_st.expr;
1668 accept_statement (st);
1673 accept_statement (st);
1677 gfc_error ("Unexpected %s statement in WHERE block at %C",
1678 gfc_ascii_statement (st));
1679 reject_statement ();
1684 while (st != ST_END_WHERE);
1690 /* Parse a FORALL block (not a simple FORALL statement). */
1693 parse_forall_block (void)
1699 accept_statement (ST_FORALL_BLOCK);
1700 top = gfc_state_stack->tail;
1702 push_state (&s, COMP_FORALL, gfc_new_block);
1704 d = add_statement ();
1705 d->op = EXEC_FORALL;
1710 st = next_statement ();
1715 case ST_POINTER_ASSIGNMENT:
1718 accept_statement (st);
1721 case ST_WHERE_BLOCK:
1722 parse_where_block ();
1725 case ST_FORALL_BLOCK:
1726 parse_forall_block ();
1730 accept_statement (st);
1737 gfc_error ("Unexpected %s statement in FORALL block at %C",
1738 gfc_ascii_statement (st));
1740 reject_statement ();
1744 while (st != ST_END_FORALL);
1750 static gfc_statement parse_executable (gfc_statement);
1752 /* parse the statements of an IF-THEN-ELSEIF-ELSE-ENDIF block. */
1755 parse_if_block (void)
1764 accept_statement (ST_IF_BLOCK);
1766 top = gfc_state_stack->tail;
1767 push_state (&s, COMP_IF, gfc_new_block);
1769 new_st.op = EXEC_IF;
1770 d = add_statement ();
1772 d->expr = top->expr;
1778 st = parse_executable (ST_NONE);
1789 ("ELSE IF statement at %C cannot follow ELSE statement at %L",
1792 reject_statement ();
1796 d = new_level (gfc_state_stack->head);
1798 d->expr = new_st.expr;
1800 accept_statement (st);
1807 gfc_error ("Duplicate ELSE statements at %L and %C",
1809 reject_statement ();
1814 else_locus = gfc_current_locus;
1816 d = new_level (gfc_state_stack->head);
1819 accept_statement (st);
1827 unexpected_statement (st);
1831 while (st != ST_ENDIF);
1834 accept_statement (st);
1838 /* Parse a SELECT block. */
1841 parse_select_block (void)
1847 accept_statement (ST_SELECT_CASE);
1849 cp = gfc_state_stack->tail;
1850 push_state (&s, COMP_SELECT, gfc_new_block);
1852 /* Make sure that the next statement is a CASE or END SELECT. */
1855 st = next_statement ();
1858 if (st == ST_END_SELECT)
1860 /* Empty SELECT CASE is OK. */
1861 accept_statement (st);
1869 ("Expected a CASE or END SELECT statement following SELECT CASE "
1872 reject_statement ();
1875 /* At this point, we're got a nonempty select block. */
1876 cp = new_level (cp);
1879 accept_statement (st);
1883 st = parse_executable (ST_NONE);
1890 cp = new_level (gfc_state_stack->head);
1892 gfc_clear_new_st ();
1894 accept_statement (st);
1900 /* Can't have an executable statement because of
1901 parse_executable(). */
1903 unexpected_statement (st);
1907 while (st != ST_END_SELECT);
1910 accept_statement (st);
1914 /* Checks to see if the current statement label closes an enddo.
1915 Returns 0 if not, 1 if closes an ENDDO correctly, or 2 (and issues
1916 an error) if it incorrectly closes an ENDDO. */
1919 check_do_closure (void)
1923 if (gfc_statement_label == NULL)
1926 for (p = gfc_state_stack; p; p = p->previous)
1927 if (p->state == COMP_DO)
1931 return 0; /* No loops to close */
1933 if (p->ext.end_do_label == gfc_statement_label)
1936 if (p == gfc_state_stack)
1940 ("End of nonblock DO statement at %C is within another block");
1944 /* At this point, the label doesn't terminate the innermost loop.
1945 Make sure it doesn't terminate another one. */
1946 for (; p; p = p->previous)
1947 if (p->state == COMP_DO && p->ext.end_do_label == gfc_statement_label)
1949 gfc_error ("End of nonblock DO statement at %C is interwoven "
1950 "with another DO loop");
1958 /* Parse a DO loop. Note that the ST_CYCLE and ST_EXIT statements are
1959 handled inside of parse_executable(), because they aren't really
1963 parse_do_block (void)
1969 s.ext.end_do_label = new_st.label;
1971 accept_statement (ST_DO);
1973 top = gfc_state_stack->tail;
1974 push_state (&s, COMP_DO, gfc_new_block);
1976 top->block = new_level (top);
1977 top->block->op = EXEC_DO;
1980 st = parse_executable (ST_NONE);
1988 if (s.ext.end_do_label != NULL
1989 && s.ext.end_do_label != gfc_statement_label)
1991 ("Statement label in ENDDO at %C doesn't match DO label");
1994 case ST_IMPLIED_ENDDO:
1998 unexpected_statement (st);
2003 accept_statement (st);
2007 /* Accept a series of executable statements. We return the first
2008 statement that doesn't fit to the caller. Any block statements are
2009 passed on to the correct handler, which usually passes the buck
2012 static gfc_statement
2013 parse_executable (gfc_statement st)
2018 st = next_statement ();
2020 for (;; st = next_statement ())
2023 close_flag = check_do_closure ();
2028 case ST_END_PROGRAM:
2031 case ST_END_FUNCTION:
2035 case ST_END_SUBROUTINE:
2040 case ST_SELECT_CASE:
2042 ("%s statement at %C cannot terminate a non-block DO loop",
2043 gfc_ascii_statement (st));
2059 accept_statement (st);
2060 if (close_flag == 1)
2061 return ST_IMPLIED_ENDDO;
2068 case ST_SELECT_CASE:
2069 parse_select_block ();
2074 if (check_do_closure () == 1)
2075 return ST_IMPLIED_ENDDO;
2078 case ST_WHERE_BLOCK:
2079 parse_where_block ();
2082 case ST_FORALL_BLOCK:
2083 parse_forall_block ();
2097 /* Parse a series of contained program units. */
2099 static void parse_progunit (gfc_statement);
2102 /* Fix the symbols for sibling functions. These are incorrectly added to
2103 the child namespace as the parser didn't know about this procedure. */
2106 gfc_fixup_sibling_symbols (gfc_symbol * sym, gfc_namespace * siblings)
2110 gfc_symbol *old_sym;
2112 for (ns = siblings; ns; ns = ns->sibling)
2114 gfc_find_sym_tree (sym->name, ns, 0, &st);
2118 old_sym = st->n.sym;
2119 if (old_sym->attr.flavor == FL_PROCEDURE && old_sym->ns == ns
2120 && ! old_sym->attr.contained)
2122 /* Replace it with the symbol from the parent namespace. */
2126 /* Free the old (local) symbol. */
2128 if (old_sym->refs == 0)
2129 gfc_free_symbol (old_sym);
2132 /* Do the same for any contined procedures. */
2133 gfc_fixup_sibling_symbols (sym, ns->contained);
2138 parse_contained (int module)
2140 gfc_namespace *ns, *parent_ns;
2141 gfc_state_data s1, s2;
2145 push_state (&s1, COMP_CONTAINS, NULL);
2146 parent_ns = gfc_current_ns;
2150 gfc_current_ns = gfc_get_namespace (parent_ns);
2152 gfc_current_ns->sibling = parent_ns->contained;
2153 parent_ns->contained = gfc_current_ns;
2155 st = next_statement ();
2164 accept_statement (st);
2167 (st == ST_FUNCTION) ? COMP_FUNCTION : COMP_SUBROUTINE,
2170 /* For internal procedures, create/update the symbol in the
2171 * parent namespace */
2175 if (gfc_get_symbol (gfc_new_block->name, parent_ns, &sym))
2177 ("Contained procedure '%s' at %C is already ambiguous",
2178 gfc_new_block->name);
2181 if (gfc_add_procedure (&sym->attr, PROC_INTERNAL,
2182 &gfc_new_block->declared_at) ==
2185 if (st == ST_FUNCTION)
2186 gfc_add_function (&sym->attr,
2187 &gfc_new_block->declared_at);
2189 gfc_add_subroutine (&sym->attr,
2190 &gfc_new_block->declared_at);
2194 gfc_commit_symbols ();
2197 sym = gfc_new_block;
2199 /* Mark this as a contained function, so it isn't replaced
2200 by other module functions. */
2201 sym->attr.contained = 1;
2203 /* Fix up any sibling functions that refer to this one. */
2204 gfc_fixup_sibling_symbols (sym, gfc_current_ns);
2206 parse_progunit (ST_NONE);
2208 gfc_current_ns->code = s2.head;
2209 gfc_current_ns = parent_ns;
2214 /* These statements are associated with the end of the host
2216 case ST_END_FUNCTION:
2218 case ST_END_PROGRAM:
2219 case ST_END_SUBROUTINE:
2220 accept_statement (st);
2224 gfc_error ("Unexpected %s statement in CONTAINS section at %C",
2225 gfc_ascii_statement (st));
2226 reject_statement ();
2230 while (st != ST_END_FUNCTION && st != ST_END_SUBROUTINE
2231 && st != ST_END_MODULE && st != ST_END_PROGRAM);
2233 /* The first namespace in the list is guaranteed to not have
2234 anything (worthwhile) in it. */
2236 gfc_current_ns = parent_ns;
2238 ns = gfc_current_ns->contained;
2239 gfc_current_ns->contained = ns->sibling;
2240 gfc_free_namespace (ns);
2246 /* Parse a PROGRAM, SUBROUTINE or FUNCTION unit. */
2249 parse_progunit (gfc_statement st)
2254 st = parse_spec (st);
2264 accept_statement (st);
2274 st = parse_executable (st);
2285 accept_statement (st);
2292 unexpected_statement (st);
2293 reject_statement ();
2294 st = next_statement ();
2300 for (p = gfc_state_stack; p; p = p->previous)
2301 if (p->state == COMP_CONTAINS)
2304 if (gfc_find_state (COMP_MODULE) == SUCCESS)
2309 gfc_error ("CONTAINS statement at %C is already in a contained "
2311 st = next_statement ();
2315 parse_contained (0);
2318 gfc_current_ns->code = gfc_state_stack->head;
2322 /* Come here to complain about a global symbol already in use as
2326 global_used (gfc_gsymbol *sym, locus *where)
2331 where = &gfc_current_locus;
2341 case GSYM_SUBROUTINE:
2342 name = "SUBROUTINE";
2347 case GSYM_BLOCK_DATA:
2348 name = "BLOCK DATA";
2354 gfc_internal_error ("gfc_gsymbol_type(): Bad type");
2358 gfc_error("Global name '%s' at %L is already being used as a %s at %L",
2359 gfc_new_block->name, where, name, &sym->where);
2363 /* Parse a block data program unit. */
2366 parse_block_data (void)
2369 static locus blank_locus;
2370 static int blank_block=0;
2373 if (gfc_new_block == NULL)
2376 gfc_error ("Blank BLOCK DATA at %C conflicts with "
2377 "prior BLOCK DATA at %L", &blank_locus);
2381 blank_locus = gfc_current_locus;
2386 s = gfc_get_gsymbol (gfc_new_block->name);
2387 if (s->type != GSYM_UNKNOWN)
2388 global_used(s, NULL);
2391 s->type = GSYM_BLOCK_DATA;
2392 s->where = gfc_current_locus;
2396 st = parse_spec (ST_NONE);
2398 while (st != ST_END_BLOCK_DATA)
2400 gfc_error ("Unexpected %s statement in BLOCK DATA at %C",
2401 gfc_ascii_statement (st));
2402 reject_statement ();
2403 st = next_statement ();
2408 /* Parse a module subprogram. */
2416 s = gfc_get_gsymbol (gfc_new_block->name);
2417 if (s->type != GSYM_UNKNOWN)
2418 global_used(s, NULL);
2421 s->type = GSYM_MODULE;
2422 s->where = gfc_current_locus;
2425 st = parse_spec (ST_NONE);
2434 parse_contained (1);
2438 accept_statement (st);
2442 gfc_error ("Unexpected %s statement in MODULE at %C",
2443 gfc_ascii_statement (st));
2445 reject_statement ();
2446 st = next_statement ();
2452 /* Add a procedure name to the global symbol table. */
2455 add_global_procedure (int sub)
2459 s = gfc_get_gsymbol(gfc_new_block->name);
2461 if (s->type != GSYM_UNKNOWN)
2462 global_used(s, NULL);
2465 s->type = sub ? GSYM_SUBROUTINE : GSYM_FUNCTION;
2466 s->where = gfc_current_locus;
2471 /* Add a program to the global symbol table. */
2474 add_global_program (void)
2478 if (gfc_new_block == NULL)
2480 s = gfc_get_gsymbol (gfc_new_block->name);
2482 if (s->type != GSYM_UNKNOWN)
2483 global_used(s, NULL);
2486 s->type = GSYM_PROGRAM;
2487 s->where = gfc_current_locus;
2492 /* Top level parser. */
2495 gfc_parse_file (void)
2497 int seen_program, errors_before, errors;
2498 gfc_state_data top, s;
2502 top.state = COMP_NONE;
2504 top.previous = NULL;
2505 top.head = top.tail = NULL;
2507 gfc_state_stack = ⊤
2509 gfc_clear_new_st ();
2511 gfc_statement_label = NULL;
2514 return FAILURE; /* Come here on unexpected EOF */
2520 st = next_statement ();
2529 goto duplicate_main;
2531 prog_locus = gfc_current_locus;
2533 push_state (&s, COMP_PROGRAM, gfc_new_block);
2534 accept_statement (st);
2535 add_global_program ();
2536 parse_progunit (ST_NONE);
2540 add_global_procedure (1);
2541 push_state (&s, COMP_SUBROUTINE, gfc_new_block);
2542 accept_statement (st);
2543 parse_progunit (ST_NONE);
2547 add_global_procedure (0);
2548 push_state (&s, COMP_FUNCTION, gfc_new_block);
2549 accept_statement (st);
2550 parse_progunit (ST_NONE);
2554 push_state (&s, COMP_BLOCK_DATA, gfc_new_block);
2555 accept_statement (st);
2556 parse_block_data ();
2560 push_state (&s, COMP_MODULE, gfc_new_block);
2561 accept_statement (st);
2563 gfc_get_errors (NULL, &errors_before);
2567 /* Anything else starts a nameless main program block. */
2570 goto duplicate_main;
2572 prog_locus = gfc_current_locus;
2574 push_state (&s, COMP_PROGRAM, gfc_new_block);
2575 parse_progunit (st);
2579 gfc_current_ns->code = s.head;
2581 gfc_resolve (gfc_current_ns);
2583 /* Dump the parse tree if requested. */
2584 if (gfc_option.verbose)
2585 gfc_show_namespace (gfc_current_ns);
2587 gfc_get_errors (NULL, &errors);
2588 if (s.state == COMP_MODULE)
2590 gfc_dump_module (s.sym->name, errors_before == errors);
2591 if (errors == 0 && ! gfc_option.flag_no_backend)
2592 gfc_generate_module_code (gfc_current_ns);
2596 if (errors == 0 && ! gfc_option.flag_no_backend)
2597 gfc_generate_code (gfc_current_ns);
2608 /* If we see a duplicate main program, shut down. If the second
2609 instance is an implied main program, ie data decls or executable
2610 statements, we're in for lots of errors. */
2611 gfc_error ("Two main PROGRAMs at %L and %C", &prog_locus);
2612 reject_statement ();