2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA
31 /* Current statement label. Zero means no statement label. Because
32 new_st can get wiped during statement matching, we have to keep it
35 gfc_st_label *gfc_statement_label;
37 static locus label_locus;
38 static jmp_buf eof_buf;
40 gfc_state_data *gfc_state_stack;
42 /* TODO: Re-order functions to kill these forward decls. */
43 static void check_statement_label (gfc_statement);
44 static void undo_new_statement (void);
45 static void reject_statement (void);
47 /* A sort of half-matching function. We try to match the word on the
48 input with the passed string. If this succeeds, we call the
49 keyword-dependent matching function that will match the rest of the
50 statement. For single keywords, the matching subroutine is
54 match_word (const char *str, match (*subr) (void), locus * old_locus)
69 gfc_current_locus = *old_locus;
77 /* Figure out what the next statement is, (mostly) regardless of
78 proper ordering. The do...while(0) is there to prevent if/else
81 #define match(keyword, subr, st) \
83 if (match_word(keyword, subr, &old_locus) == MATCH_YES) \
86 undo_new_statement (); \
90 decode_statement (void)
101 gfc_clear_error (); /* Clear any pending errors. */
102 gfc_clear_warning (); /* Clear any pending warnings. */
104 if (gfc_match_eos () == MATCH_YES)
107 old_locus = gfc_current_locus;
109 /* Try matching a data declaration or function declaration. The
110 input "REALFUNCTIONA(N)" can mean several things in different
111 contexts, so it (and its relatives) get special treatment. */
113 if (gfc_current_state () == COMP_NONE
114 || gfc_current_state () == COMP_INTERFACE
115 || gfc_current_state () == COMP_CONTAINS)
117 m = gfc_match_function_decl ();
120 else if (m == MATCH_ERROR)
124 gfc_current_locus = old_locus;
127 /* Match statements whose error messages are meant to be overwritten
128 by something better. */
130 match (NULL, gfc_match_assignment, ST_ASSIGNMENT);
131 match (NULL, gfc_match_pointer_assignment, ST_POINTER_ASSIGNMENT);
132 match (NULL, gfc_match_st_function, ST_STATEMENT_FUNCTION);
134 match (NULL, gfc_match_data_decl, ST_DATA_DECL);
135 match (NULL, gfc_match_enumerator_def, ST_ENUMERATOR);
137 /* Try to match a subroutine statement, which has the same optional
138 prefixes that functions can have. */
140 if (gfc_match_subroutine () == MATCH_YES)
141 return ST_SUBROUTINE;
143 gfc_current_locus = old_locus;
145 /* Check for the IF, DO, SELECT, WHERE and FORALL statements, which
146 might begin with a block label. The match functions for these
147 statements are unusual in that their keyword is not seen before
148 the matcher is called. */
150 if (gfc_match_if (&st) == MATCH_YES)
153 gfc_current_locus = old_locus;
155 if (gfc_match_where (&st) == MATCH_YES)
158 gfc_current_locus = old_locus;
160 if (gfc_match_forall (&st) == MATCH_YES)
163 gfc_current_locus = old_locus;
165 match (NULL, gfc_match_do, ST_DO);
166 match (NULL, gfc_match_select, ST_SELECT_CASE);
168 /* General statement matching: Instead of testing every possible
169 statement, we eliminate most possibilities by peeking at the
172 c = gfc_peek_char ();
177 match ("allocate", gfc_match_allocate, ST_ALLOCATE);
178 match ("allocatable", gfc_match_allocatable, ST_ATTR_DECL);
179 match ("assign", gfc_match_assign, ST_LABEL_ASSIGNMENT);
183 match ("backspace", gfc_match_backspace, ST_BACKSPACE);
184 match ("block data", gfc_match_block_data, ST_BLOCK_DATA);
188 match ("call", gfc_match_call, ST_CALL);
189 match ("close", gfc_match_close, ST_CLOSE);
190 match ("continue", gfc_match_continue, ST_CONTINUE);
191 match ("cycle", gfc_match_cycle, ST_CYCLE);
192 match ("case", gfc_match_case, ST_CASE);
193 match ("common", gfc_match_common, ST_COMMON);
194 match ("contains", gfc_match_eos, ST_CONTAINS);
198 match ("deallocate", gfc_match_deallocate, ST_DEALLOCATE);
199 match ("data", gfc_match_data, ST_DATA);
200 match ("dimension", gfc_match_dimension, ST_ATTR_DECL);
204 match ("end file", gfc_match_endfile, ST_END_FILE);
205 match ("exit", gfc_match_exit, ST_EXIT);
206 match ("else", gfc_match_else, ST_ELSE);
207 match ("else where", gfc_match_elsewhere, ST_ELSEWHERE);
208 match ("else if", gfc_match_elseif, ST_ELSEIF);
209 match ("enum , bind ( c )", gfc_match_enum, ST_ENUM);
211 if (gfc_match_end (&st) == MATCH_YES)
214 match ("entry% ", gfc_match_entry, ST_ENTRY);
215 match ("equivalence", gfc_match_equivalence, ST_EQUIVALENCE);
216 match ("external", gfc_match_external, ST_ATTR_DECL);
220 match ("flush", gfc_match_flush, ST_FLUSH);
221 match ("format", gfc_match_format, ST_FORMAT);
225 match ("go to", gfc_match_goto, ST_GOTO);
229 match ("inquire", gfc_match_inquire, ST_INQUIRE);
230 match ("implicit", gfc_match_implicit, ST_IMPLICIT);
231 match ("implicit% none", gfc_match_implicit_none, ST_IMPLICIT_NONE);
232 match ("interface", gfc_match_interface, ST_INTERFACE);
233 match ("intent", gfc_match_intent, ST_ATTR_DECL);
234 match ("intrinsic", gfc_match_intrinsic, ST_ATTR_DECL);
238 match ("module% procedure% ", gfc_match_modproc, ST_MODULE_PROC);
239 match ("module", gfc_match_module, ST_MODULE);
243 match ("nullify", gfc_match_nullify, ST_NULLIFY);
244 match ("namelist", gfc_match_namelist, ST_NAMELIST);
248 match ("open", gfc_match_open, ST_OPEN);
249 match ("optional", gfc_match_optional, ST_ATTR_DECL);
253 match ("print", gfc_match_print, ST_WRITE);
254 match ("parameter", gfc_match_parameter, ST_PARAMETER);
255 match ("pause", gfc_match_pause, ST_PAUSE);
256 match ("pointer", gfc_match_pointer, ST_ATTR_DECL);
257 if (gfc_match_private (&st) == MATCH_YES)
259 match ("program", gfc_match_program, ST_PROGRAM);
260 if (gfc_match_public (&st) == MATCH_YES)
265 match ("read", gfc_match_read, ST_READ);
266 match ("return", gfc_match_return, ST_RETURN);
267 match ("rewind", gfc_match_rewind, ST_REWIND);
271 match ("sequence", gfc_match_eos, ST_SEQUENCE);
272 match ("stop", gfc_match_stop, ST_STOP);
273 match ("save", gfc_match_save, ST_ATTR_DECL);
277 match ("target", gfc_match_target, ST_ATTR_DECL);
278 match ("type", gfc_match_derived_decl, ST_DERIVED_DECL);
282 match ("use% ", gfc_match_use, ST_USE);
286 match ("write", gfc_match_write, ST_WRITE);
290 /* All else has failed, so give up. See if any of the matchers has
291 stored an error message of some sort. */
293 if (gfc_error_check () == 0)
294 gfc_error_now ("Unclassifiable statement at %C");
298 gfc_error_recovery ();
306 /* Get the next statement in free form source. */
314 gfc_gobble_whitespace ();
316 c = gfc_peek_char ();
320 /* Found a statement label? */
321 m = gfc_match_st_label (&gfc_statement_label, 0);
323 d = gfc_peek_char ();
324 if (m != MATCH_YES || !gfc_is_whitespace (d))
328 /* Skip the bad statement label. */
329 gfc_warning_now ("Ignoring bad statement label at %C");
330 c = gfc_next_char ();
336 label_locus = gfc_current_locus;
338 if (gfc_statement_label->value == 0)
340 gfc_warning_now ("Ignoring statement label of zero at %C");
341 gfc_free_st_label (gfc_statement_label);
342 gfc_statement_label = NULL;
345 gfc_gobble_whitespace ();
347 if (gfc_match_eos () == MATCH_YES)
350 ("Ignoring statement label in empty statement at %C");
351 gfc_free_st_label (gfc_statement_label);
352 gfc_statement_label = NULL;
358 return decode_statement ();
362 /* Get the next statement in fixed-form source. */
367 int label, digit_flag, i;
372 return decode_statement ();
374 /* Skip past the current label field, parsing a statement label if
375 one is there. This is a weird number parser, since the number is
376 contained within five columns and can have any kind of embedded
377 spaces. We also check for characters that make the rest of the
383 for (i = 0; i < 5; i++)
385 c = gfc_next_char_literal (0);
402 label = label * 10 + c - '0';
403 label_locus = gfc_current_locus;
407 /* Comments have already been skipped by the time we get
408 here so don't bother checking for them. */
411 gfc_buffer_error (0);
412 gfc_error ("Non-numeric character in statement label at %C");
420 gfc_warning_now ("Zero is not a valid statement label at %C");
423 /* We've found a valid statement label. */
424 gfc_statement_label = gfc_get_st_label (label);
428 /* Since this line starts a statement, it cannot be a continuation
429 of a previous statement. If we see something here besides a
430 space or zero, it must be a bad continuation line. */
432 c = gfc_next_char_literal (0);
436 if (c != ' ' && c!= '0')
438 gfc_buffer_error (0);
439 gfc_error ("Bad continuation line at %C");
443 /* Now that we've taken care of the statement label columns, we have
444 to make sure that the first nonblank character is not a '!'. If
445 it is, the rest of the line is a comment. */
449 loc = gfc_current_locus;
450 c = gfc_next_char_literal (0);
452 while (gfc_is_whitespace (c));
456 gfc_current_locus = loc;
458 if (gfc_match_eos () == MATCH_YES)
461 /* At this point, we've got a nonblank statement to parse. */
462 return decode_statement ();
466 gfc_warning ("Statement label in blank line will be " "ignored at %C");
472 /* Return the next non-ST_NONE statement to the caller. We also worry
473 about including files and the ends of include files at this stage. */
476 next_statement (void)
480 gfc_new_block = NULL;
484 gfc_statement_label = NULL;
485 gfc_buffer_error (1);
489 if (gfc_option.warn_line_truncation
490 && gfc_current_locus.lb->truncated)
491 gfc_warning_now ("Line truncated at %C");
496 gfc_skip_comments ();
505 (gfc_current_form == FORM_FIXED) ? next_fixed () : next_free ();
511 gfc_buffer_error (0);
514 check_statement_label (st);
520 /****************************** Parser ***********************************/
522 /* The parser subroutines are of type 'try' that fail if the file ends
525 /* Macros that expand to case-labels for various classes of
526 statements. Start with executable statements that directly do
529 #define case_executable case ST_ALLOCATE: case ST_BACKSPACE: case ST_CALL: \
530 case ST_CLOSE: case ST_CONTINUE: case ST_DEALLOCATE: case ST_END_FILE: \
531 case ST_GOTO: case ST_INQUIRE: case ST_NULLIFY: case ST_OPEN: \
532 case ST_READ: case ST_RETURN: case ST_REWIND: case ST_SIMPLE_IF: \
533 case ST_PAUSE: case ST_STOP: case ST_WRITE: case ST_ASSIGNMENT: \
534 case ST_POINTER_ASSIGNMENT: case ST_EXIT: case ST_CYCLE: \
535 case ST_ARITHMETIC_IF: case ST_WHERE: case ST_FORALL: \
536 case ST_LABEL_ASSIGNMENT: case ST_FLUSH
538 /* Statements that mark other executable statements. */
540 #define case_exec_markers case ST_DO: case ST_FORALL_BLOCK: case ST_IF_BLOCK: \
541 case ST_WHERE_BLOCK: case ST_SELECT_CASE
543 /* Declaration statements */
545 #define case_decl case ST_ATTR_DECL: case ST_COMMON: case ST_DATA_DECL: \
546 case ST_EQUIVALENCE: case ST_NAMELIST: case ST_STATEMENT_FUNCTION: \
547 case ST_TYPE: case ST_INTERFACE
549 /* Block end statements. Errors associated with interchanging these
550 are detected in gfc_match_end(). */
552 #define case_end case ST_END_BLOCK_DATA: case ST_END_FUNCTION: \
553 case ST_END_PROGRAM: case ST_END_SUBROUTINE
556 /* Push a new state onto the stack. */
559 push_state (gfc_state_data * p, gfc_compile_state new_state, gfc_symbol * sym)
562 p->state = new_state;
563 p->previous = gfc_state_stack;
565 p->head = p->tail = NULL;
566 p->do_variable = NULL;
572 /* Pop the current state. */
578 gfc_state_stack = gfc_state_stack->previous;
582 /* Try to find the given state in the state stack. */
585 gfc_find_state (gfc_compile_state state)
589 for (p = gfc_state_stack; p; p = p->previous)
590 if (p->state == state)
593 return (p == NULL) ? FAILURE : SUCCESS;
597 /* Starts a new level in the statement list. */
600 new_level (gfc_code * q)
604 p = q->block = gfc_get_code ();
606 gfc_state_stack->head = gfc_state_stack->tail = p;
612 /* Add the current new_st code structure and adds it to the current
613 program unit. As a side-effect, it zeroes the new_st. */
623 p->loc = gfc_current_locus;
625 if (gfc_state_stack->head == NULL)
626 gfc_state_stack->head = p;
628 gfc_state_stack->tail->next = p;
630 while (p->next != NULL)
633 gfc_state_stack->tail = p;
641 /* Frees everything associated with the current statement. */
644 undo_new_statement (void)
646 gfc_free_statements (new_st.block);
647 gfc_free_statements (new_st.next);
648 gfc_free_statement (&new_st);
653 /* If the current statement has a statement label, make sure that it
654 is allowed to, or should have one. */
657 check_statement_label (gfc_statement st)
661 if (gfc_statement_label == NULL)
664 gfc_error ("FORMAT statement at %L does not have a statement label",
672 case ST_END_FUNCTION:
673 case ST_END_SUBROUTINE:
679 type = ST_LABEL_TARGET;
683 type = ST_LABEL_FORMAT;
686 /* Statement labels are not restricted from appearing on a
687 particular line. However, there are plenty of situations
688 where the resulting label can't be referenced. */
691 type = ST_LABEL_BAD_TARGET;
695 gfc_define_st_label (gfc_statement_label, type, &label_locus);
697 new_st.here = gfc_statement_label;
701 /* Figures out what the enclosing program unit is. This will be a
702 function, subroutine, program, block data or module. */
705 gfc_enclosing_unit (gfc_compile_state * result)
709 for (p = gfc_state_stack; p; p = p->previous)
710 if (p->state == COMP_FUNCTION || p->state == COMP_SUBROUTINE
711 || p->state == COMP_MODULE || p->state == COMP_BLOCK_DATA
712 || p->state == COMP_PROGRAM)
721 *result = COMP_PROGRAM;
726 /* Translate a statement enum to a string. */
729 gfc_ascii_statement (gfc_statement st)
735 case ST_ARITHMETIC_IF:
736 p = _("arithmetic IF");
742 p = _("attribute declaration");
772 p = _("data declaration");
780 case ST_DERIVED_DECL:
781 p = _("derived type declaration");
795 case ST_END_BLOCK_DATA:
796 p = "END BLOCK DATA";
807 case ST_END_FUNCTION:
813 case ST_END_INTERFACE:
825 case ST_END_SUBROUTINE:
826 p = "END SUBROUTINE";
846 case ST_FORALL_BLOCK: /* Fall through */
865 case ST_IMPLICIT_NONE:
868 case ST_IMPLIED_ENDDO:
869 p = _("implied END DO");
893 p = "MODULE PROCEDURE";
928 case ST_WHERE_BLOCK: /* Fall through */
938 case ST_POINTER_ASSIGNMENT:
939 p = _("pointer assignment");
950 case ST_STATEMENT_FUNCTION:
951 p = "STATEMENT FUNCTION";
953 case ST_LABEL_ASSIGNMENT:
954 p = "LABEL ASSIGNMENT";
957 p = "ENUM DEFINITION";
960 p = "ENUMERATOR DEFINITION";
966 gfc_internal_error ("gfc_ascii_statement(): Bad statement code");
973 /* Create a symbol for the main program and assign it to ns->proc_name. */
976 main_program_symbol (gfc_namespace * ns)
978 gfc_symbol *main_program;
979 symbol_attribute attr;
981 gfc_get_symbol ("MAIN__", ns, &main_program);
982 gfc_clear_attr (&attr);
983 attr.flavor = FL_PROCEDURE;
984 attr.proc = PROC_UNKNOWN;
986 attr.access = ACCESS_PUBLIC;
987 attr.is_main_program = 1;
988 main_program->attr = attr;
989 main_program->declared_at = gfc_current_locus;
990 ns->proc_name = main_program;
991 gfc_commit_symbols ();
995 /* Do whatever is necessary to accept the last statement. */
998 accept_statement (gfc_statement st)
1007 case ST_IMPLICIT_NONE:
1008 gfc_set_implicit_none ();
1017 gfc_current_ns->proc_name = gfc_new_block;
1020 /* If the statement is the end of a block, lay down a special code
1021 that allows a branch to the end of the block from within the
1026 if (gfc_statement_label != NULL)
1028 new_st.op = EXEC_NOP;
1034 /* The end-of-program unit statements do not get the special
1035 marker and require a statement of some sort if they are a
1038 case ST_END_PROGRAM:
1039 case ST_END_FUNCTION:
1040 case ST_END_SUBROUTINE:
1041 if (gfc_statement_label != NULL)
1043 new_st.op = EXEC_RETURN;
1059 gfc_commit_symbols ();
1060 gfc_warning_check ();
1061 gfc_clear_new_st ();
1065 /* Undo anything tentative that has been built for the current
1069 reject_statement (void)
1072 gfc_undo_symbols ();
1073 gfc_clear_warning ();
1074 undo_new_statement ();
1078 /* Generic complaint about an out of order statement. We also do
1079 whatever is necessary to clean up. */
1082 unexpected_statement (gfc_statement st)
1085 gfc_error ("Unexpected %s statement at %C", gfc_ascii_statement (st));
1087 reject_statement ();
1091 /* Given the next statement seen by the matcher, make sure that it is
1092 in proper order with the last. This subroutine is initialized by
1093 calling it with an argument of ST_NONE. If there is a problem, we
1094 issue an error and return FAILURE. Otherwise we return SUCCESS.
1096 Individual parsers need to verify that the statements seen are
1097 valid before calling here, ie ENTRY statements are not allowed in
1098 INTERFACE blocks. The following diagram is taken from the standard:
1100 +---------------------------------------+
1101 | program subroutine function module |
1102 +---------------------------------------+
1104 |---------------------------------------+
1106 | +-----------+------------------+
1107 | | parameter | implicit |
1108 | +-----------+------------------+
1109 | format | | derived type |
1110 | entry | parameter | interface |
1111 | | data | specification |
1112 | | | statement func |
1113 | +-----------+------------------+
1114 | | data | executable |
1115 +--------+-----------+------------------+
1117 +---------------------------------------+
1118 | internal module/subprogram |
1119 +---------------------------------------+
1121 +---------------------------------------+
1128 { ORDER_START, ORDER_USE, ORDER_IMPLICIT_NONE, ORDER_IMPLICIT,
1129 ORDER_SPEC, ORDER_EXEC
1132 gfc_statement last_statement;
1138 verify_st_order (st_state * p, gfc_statement st)
1144 p->state = ORDER_START;
1148 if (p->state > ORDER_USE)
1150 p->state = ORDER_USE;
1153 case ST_IMPLICIT_NONE:
1154 if (p->state > ORDER_IMPLICIT_NONE)
1157 /* The '>' sign cannot be a '>=', because a FORMAT or ENTRY
1158 statement disqualifies a USE but not an IMPLICIT NONE.
1159 Duplicate IMPLICIT NONEs are caught when the implicit types
1162 p->state = ORDER_IMPLICIT_NONE;
1166 if (p->state > ORDER_IMPLICIT)
1168 p->state = ORDER_IMPLICIT;
1173 if (p->state < ORDER_IMPLICIT_NONE)
1174 p->state = ORDER_IMPLICIT_NONE;
1178 if (p->state >= ORDER_EXEC)
1180 if (p->state < ORDER_IMPLICIT)
1181 p->state = ORDER_IMPLICIT;
1185 if (p->state < ORDER_SPEC)
1186 p->state = ORDER_SPEC;
1191 case ST_DERIVED_DECL:
1193 if (p->state >= ORDER_EXEC)
1195 if (p->state < ORDER_SPEC)
1196 p->state = ORDER_SPEC;
1201 if (p->state < ORDER_EXEC)
1202 p->state = ORDER_EXEC;
1207 ("Unexpected %s statement in verify_st_order() at %C",
1208 gfc_ascii_statement (st));
1211 /* All is well, record the statement in case we need it next time. */
1212 p->where = gfc_current_locus;
1213 p->last_statement = st;
1217 gfc_error ("%s statement at %C cannot follow %s statement at %L",
1218 gfc_ascii_statement (st),
1219 gfc_ascii_statement (p->last_statement), &p->where);
1225 /* Handle an unexpected end of file. This is a show-stopper... */
1227 static void unexpected_eof (void) ATTRIBUTE_NORETURN;
1230 unexpected_eof (void)
1234 gfc_error ("Unexpected end of file in '%s'", gfc_source_file);
1236 /* Memory cleanup. Move to "second to last". */
1237 for (p = gfc_state_stack; p && p->previous && p->previous->previous;
1240 gfc_current_ns->code = (p && p->previous) ? p->head : NULL;
1243 longjmp (eof_buf, 1);
1247 /* Parse a derived type. */
1250 parse_derived (void)
1252 int compiling_type, seen_private, seen_sequence, seen_component, error_flag;
1259 accept_statement (ST_DERIVED_DECL);
1260 push_state (&s, COMP_DERIVED, gfc_new_block);
1262 gfc_new_block->component_access = ACCESS_PUBLIC;
1269 while (compiling_type)
1271 st = next_statement ();
1278 accept_statement (st);
1285 if (!seen_component)
1287 gfc_error ("Derived type definition at %C has no components");
1291 accept_statement (ST_END_TYPE);
1295 if (gfc_find_state (COMP_MODULE) == FAILURE)
1298 ("PRIVATE statement in TYPE at %C must be inside a MODULE");
1305 gfc_error ("PRIVATE statement at %C must precede "
1306 "structure components");
1313 gfc_error ("Duplicate PRIVATE statement at %C");
1317 s.sym->component_access = ACCESS_PRIVATE;
1318 accept_statement (ST_PRIVATE);
1325 gfc_error ("SEQUENCE statement at %C must precede "
1326 "structure components");
1331 if (gfc_current_block ()->attr.sequence)
1332 gfc_warning ("SEQUENCE attribute at %C already specified in "
1337 gfc_error ("Duplicate SEQUENCE statement at %C");
1342 gfc_add_sequence (&gfc_current_block ()->attr,
1343 gfc_current_block ()->name, NULL);
1347 unexpected_statement (st);
1352 /* Sanity checks on the structure. If the structure has the
1353 SEQUENCE attribute, then all component structures must also have
1355 if (error_flag == 0 && gfc_current_block ()->attr.sequence)
1356 for (c = gfc_current_block ()->components; c; c = c->next)
1358 if (c->ts.type == BT_DERIVED && c->ts.derived->attr.sequence == 0)
1361 ("Component %s of SEQUENCE type declared at %C does not "
1362 "have the SEQUENCE attribute", c->ts.derived->name);
1371 /* Parse an ENUM. */
1380 int seen_enumerator = 0;
1384 push_state (&s, COMP_ENUM, gfc_new_block);
1388 while (compiling_enum)
1390 st = next_statement ();
1398 seen_enumerator = 1;
1399 accept_statement (st);
1404 if (!seen_enumerator)
1406 gfc_error ("ENUM declaration at %C has no ENUMERATORS");
1409 accept_statement (st);
1413 gfc_free_enum_history ();
1414 unexpected_statement (st);
1421 /* Parse an interface. We must be able to deal with the possibility
1422 of recursive interfaces. The parse_spec() subroutine is mutually
1423 recursive with parse_interface(). */
1425 static gfc_statement parse_spec (gfc_statement);
1428 parse_interface (void)
1430 gfc_compile_state new_state, current_state;
1431 gfc_symbol *prog_unit, *sym;
1432 gfc_interface_info save;
1433 gfc_state_data s1, s2;
1436 accept_statement (ST_INTERFACE);
1438 current_interface.ns = gfc_current_ns;
1439 save = current_interface;
1441 sym = (current_interface.type == INTERFACE_GENERIC
1442 || current_interface.type == INTERFACE_USER_OP) ? gfc_new_block : NULL;
1444 push_state (&s1, COMP_INTERFACE, sym);
1445 current_state = COMP_NONE;
1448 gfc_current_ns = gfc_get_namespace (current_interface.ns, 0);
1450 st = next_statement ();
1457 new_state = COMP_SUBROUTINE;
1458 gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
1459 gfc_new_block->formal, NULL);
1463 new_state = COMP_FUNCTION;
1464 gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
1465 gfc_new_block->formal, NULL);
1468 case ST_MODULE_PROC: /* The module procedure matcher makes
1469 sure the context is correct. */
1470 accept_statement (st);
1471 gfc_free_namespace (gfc_current_ns);
1474 case ST_END_INTERFACE:
1475 gfc_free_namespace (gfc_current_ns);
1476 gfc_current_ns = current_interface.ns;
1480 gfc_error ("Unexpected %s statement in INTERFACE block at %C",
1481 gfc_ascii_statement (st));
1482 reject_statement ();
1483 gfc_free_namespace (gfc_current_ns);
1488 /* Make sure that a generic interface has only subroutines or
1489 functions and that the generic name has the right attribute. */
1490 if (current_interface.type == INTERFACE_GENERIC)
1492 if (current_state == COMP_NONE)
1494 if (new_state == COMP_FUNCTION)
1495 gfc_add_function (&sym->attr, sym->name, NULL);
1496 else if (new_state == COMP_SUBROUTINE)
1497 gfc_add_subroutine (&sym->attr, sym->name, NULL);
1499 current_state = new_state;
1503 if (new_state != current_state)
1505 if (new_state == COMP_SUBROUTINE)
1507 ("SUBROUTINE at %C does not belong in a generic function "
1510 if (new_state == COMP_FUNCTION)
1512 ("FUNCTION at %C does not belong in a generic subroutine "
1518 push_state (&s2, new_state, gfc_new_block);
1519 accept_statement (st);
1520 prog_unit = gfc_new_block;
1521 prog_unit->formal_ns = gfc_current_ns;
1524 /* Read data declaration statements. */
1525 st = parse_spec (ST_NONE);
1527 if (st != ST_END_SUBROUTINE && st != ST_END_FUNCTION)
1529 gfc_error ("Unexpected %s statement at %C in INTERFACE body",
1530 gfc_ascii_statement (st));
1531 reject_statement ();
1535 current_interface = save;
1536 gfc_add_interface (prog_unit);
1546 /* Parse a set of specification statements. Returns the statement
1547 that doesn't fit. */
1549 static gfc_statement
1550 parse_spec (gfc_statement st)
1554 verify_st_order (&ss, ST_NONE);
1556 st = next_statement ();
1566 case ST_DATA: /* Not allowed in interfaces */
1567 if (gfc_current_state () == COMP_INTERFACE)
1573 case ST_IMPLICIT_NONE:
1578 case ST_DERIVED_DECL:
1580 if (verify_st_order (&ss, st) == FAILURE)
1582 reject_statement ();
1583 st = next_statement ();
1593 case ST_DERIVED_DECL:
1599 if (gfc_current_state () != COMP_MODULE)
1601 gfc_error ("%s statement must appear in a MODULE",
1602 gfc_ascii_statement (st));
1606 if (gfc_current_ns->default_access != ACCESS_UNKNOWN)
1608 gfc_error ("%s statement at %C follows another accessibility "
1609 "specification", gfc_ascii_statement (st));
1613 gfc_current_ns->default_access = (st == ST_PUBLIC)
1614 ? ACCESS_PUBLIC : ACCESS_PRIVATE;
1622 accept_statement (st);
1623 st = next_statement ();
1627 accept_statement (st);
1629 st = next_statement ();
1640 /* Parse a WHERE block, (not a simple WHERE statement). */
1643 parse_where_block (void)
1645 int seen_empty_else;
1650 accept_statement (ST_WHERE_BLOCK);
1651 top = gfc_state_stack->tail;
1653 push_state (&s, COMP_WHERE, gfc_new_block);
1655 d = add_statement ();
1656 d->expr = top->expr;
1662 seen_empty_else = 0;
1666 st = next_statement ();
1672 case ST_WHERE_BLOCK:
1673 parse_where_block ();
1678 accept_statement (st);
1682 if (seen_empty_else)
1685 ("ELSEWHERE statement at %C follows previous unmasked "
1690 if (new_st.expr == NULL)
1691 seen_empty_else = 1;
1693 d = new_level (gfc_state_stack->head);
1695 d->expr = new_st.expr;
1697 accept_statement (st);
1702 accept_statement (st);
1706 gfc_error ("Unexpected %s statement in WHERE block at %C",
1707 gfc_ascii_statement (st));
1708 reject_statement ();
1713 while (st != ST_END_WHERE);
1719 /* Parse a FORALL block (not a simple FORALL statement). */
1722 parse_forall_block (void)
1728 accept_statement (ST_FORALL_BLOCK);
1729 top = gfc_state_stack->tail;
1731 push_state (&s, COMP_FORALL, gfc_new_block);
1733 d = add_statement ();
1734 d->op = EXEC_FORALL;
1739 st = next_statement ();
1744 case ST_POINTER_ASSIGNMENT:
1747 accept_statement (st);
1750 case ST_WHERE_BLOCK:
1751 parse_where_block ();
1754 case ST_FORALL_BLOCK:
1755 parse_forall_block ();
1759 accept_statement (st);
1766 gfc_error ("Unexpected %s statement in FORALL block at %C",
1767 gfc_ascii_statement (st));
1769 reject_statement ();
1773 while (st != ST_END_FORALL);
1779 static gfc_statement parse_executable (gfc_statement);
1781 /* parse the statements of an IF-THEN-ELSEIF-ELSE-ENDIF block. */
1784 parse_if_block (void)
1793 accept_statement (ST_IF_BLOCK);
1795 top = gfc_state_stack->tail;
1796 push_state (&s, COMP_IF, gfc_new_block);
1798 new_st.op = EXEC_IF;
1799 d = add_statement ();
1801 d->expr = top->expr;
1807 st = parse_executable (ST_NONE);
1818 ("ELSE IF statement at %C cannot follow ELSE statement at %L",
1821 reject_statement ();
1825 d = new_level (gfc_state_stack->head);
1827 d->expr = new_st.expr;
1829 accept_statement (st);
1836 gfc_error ("Duplicate ELSE statements at %L and %C",
1838 reject_statement ();
1843 else_locus = gfc_current_locus;
1845 d = new_level (gfc_state_stack->head);
1848 accept_statement (st);
1856 unexpected_statement (st);
1860 while (st != ST_ENDIF);
1863 accept_statement (st);
1867 /* Parse a SELECT block. */
1870 parse_select_block (void)
1876 accept_statement (ST_SELECT_CASE);
1878 cp = gfc_state_stack->tail;
1879 push_state (&s, COMP_SELECT, gfc_new_block);
1881 /* Make sure that the next statement is a CASE or END SELECT. */
1884 st = next_statement ();
1887 if (st == ST_END_SELECT)
1889 /* Empty SELECT CASE is OK. */
1890 accept_statement (st);
1898 ("Expected a CASE or END SELECT statement following SELECT CASE "
1901 reject_statement ();
1904 /* At this point, we're got a nonempty select block. */
1905 cp = new_level (cp);
1908 accept_statement (st);
1912 st = parse_executable (ST_NONE);
1919 cp = new_level (gfc_state_stack->head);
1921 gfc_clear_new_st ();
1923 accept_statement (st);
1929 /* Can't have an executable statement because of
1930 parse_executable(). */
1932 unexpected_statement (st);
1936 while (st != ST_END_SELECT);
1939 accept_statement (st);
1943 /* Given a symbol, make sure it is not an iteration variable for a DO
1944 statement. This subroutine is called when the symbol is seen in a
1945 context that causes it to become redefined. If the symbol is an
1946 iterator, we generate an error message and return nonzero. */
1949 gfc_check_do_variable (gfc_symtree *st)
1953 for (s=gfc_state_stack; s; s = s->previous)
1954 if (s->do_variable == st)
1956 gfc_error_now("Variable '%s' at %C cannot be redefined inside "
1957 "loop beginning at %L", st->name, &s->head->loc);
1965 /* Checks to see if the current statement label closes an enddo.
1966 Returns 0 if not, 1 if closes an ENDDO correctly, or 2 (and issues
1967 an error) if it incorrectly closes an ENDDO. */
1970 check_do_closure (void)
1974 if (gfc_statement_label == NULL)
1977 for (p = gfc_state_stack; p; p = p->previous)
1978 if (p->state == COMP_DO)
1982 return 0; /* No loops to close */
1984 if (p->ext.end_do_label == gfc_statement_label)
1987 if (p == gfc_state_stack)
1991 ("End of nonblock DO statement at %C is within another block");
1995 /* At this point, the label doesn't terminate the innermost loop.
1996 Make sure it doesn't terminate another one. */
1997 for (; p; p = p->previous)
1998 if (p->state == COMP_DO && p->ext.end_do_label == gfc_statement_label)
2000 gfc_error ("End of nonblock DO statement at %C is interwoven "
2001 "with another DO loop");
2009 /* Parse a DO loop. Note that the ST_CYCLE and ST_EXIT statements are
2010 handled inside of parse_executable(), because they aren't really
2014 parse_do_block (void)
2021 s.ext.end_do_label = new_st.label;
2023 if (new_st.ext.iterator != NULL)
2024 stree = new_st.ext.iterator->var->symtree;
2028 accept_statement (ST_DO);
2030 top = gfc_state_stack->tail;
2031 push_state (&s, COMP_DO, gfc_new_block);
2033 s.do_variable = stree;
2035 top->block = new_level (top);
2036 top->block->op = EXEC_DO;
2039 st = parse_executable (ST_NONE);
2047 if (s.ext.end_do_label != NULL
2048 && s.ext.end_do_label != gfc_statement_label)
2050 ("Statement label in ENDDO at %C doesn't match DO label");
2052 if (gfc_statement_label != NULL)
2054 new_st.op = EXEC_NOP;
2059 case ST_IMPLIED_ENDDO:
2063 unexpected_statement (st);
2068 accept_statement (st);
2072 /* Accept a series of executable statements. We return the first
2073 statement that doesn't fit to the caller. Any block statements are
2074 passed on to the correct handler, which usually passes the buck
2077 static gfc_statement
2078 parse_executable (gfc_statement st)
2083 st = next_statement ();
2085 for (;; st = next_statement ())
2088 close_flag = check_do_closure ();
2093 case ST_END_PROGRAM:
2096 case ST_END_FUNCTION:
2100 case ST_END_SUBROUTINE:
2105 case ST_SELECT_CASE:
2107 ("%s statement at %C cannot terminate a non-block DO loop",
2108 gfc_ascii_statement (st));
2124 accept_statement (st);
2125 if (close_flag == 1)
2126 return ST_IMPLIED_ENDDO;
2133 case ST_SELECT_CASE:
2134 parse_select_block ();
2139 if (check_do_closure () == 1)
2140 return ST_IMPLIED_ENDDO;
2143 case ST_WHERE_BLOCK:
2144 parse_where_block ();
2147 case ST_FORALL_BLOCK:
2148 parse_forall_block ();
2162 /* Parse a series of contained program units. */
2164 static void parse_progunit (gfc_statement);
2167 /* Fix the symbols for sibling functions. These are incorrectly added to
2168 the child namespace as the parser didn't know about this procedure. */
2171 gfc_fixup_sibling_symbols (gfc_symbol * sym, gfc_namespace * siblings)
2175 gfc_symbol *old_sym;
2177 sym->attr.referenced = 1;
2178 for (ns = siblings; ns; ns = ns->sibling)
2180 gfc_find_sym_tree (sym->name, ns, 0, &st);
2184 old_sym = st->n.sym;
2185 if ((old_sym->attr.flavor == FL_PROCEDURE
2186 || old_sym->ts.type == BT_UNKNOWN)
2187 && old_sym->ns == ns
2188 && ! old_sym->attr.contained)
2190 /* Replace it with the symbol from the parent namespace. */
2194 /* Free the old (local) symbol. */
2196 if (old_sym->refs == 0)
2197 gfc_free_symbol (old_sym);
2200 /* Do the same for any contained procedures. */
2201 gfc_fixup_sibling_symbols (sym, ns->contained);
2206 parse_contained (int module)
2208 gfc_namespace *ns, *parent_ns;
2209 gfc_state_data s1, s2;
2214 push_state (&s1, COMP_CONTAINS, NULL);
2215 parent_ns = gfc_current_ns;
2219 gfc_current_ns = gfc_get_namespace (parent_ns, 1);
2221 gfc_current_ns->sibling = parent_ns->contained;
2222 parent_ns->contained = gfc_current_ns;
2224 st = next_statement ();
2233 accept_statement (st);
2236 (st == ST_FUNCTION) ? COMP_FUNCTION : COMP_SUBROUTINE,
2239 /* For internal procedures, create/update the symbol in the
2240 parent namespace. */
2244 if (gfc_get_symbol (gfc_new_block->name, parent_ns, &sym))
2246 ("Contained procedure '%s' at %C is already ambiguous",
2247 gfc_new_block->name);
2250 if (gfc_add_procedure (&sym->attr, PROC_INTERNAL, sym->name,
2251 &gfc_new_block->declared_at) ==
2254 if (st == ST_FUNCTION)
2255 gfc_add_function (&sym->attr, sym->name,
2256 &gfc_new_block->declared_at);
2258 gfc_add_subroutine (&sym->attr, sym->name,
2259 &gfc_new_block->declared_at);
2263 gfc_commit_symbols ();
2266 sym = gfc_new_block;
2268 /* Mark this as a contained function, so it isn't replaced
2269 by other module functions. */
2270 sym->attr.contained = 1;
2271 sym->attr.referenced = 1;
2273 parse_progunit (ST_NONE);
2275 /* Fix up any sibling functions that refer to this one. */
2276 gfc_fixup_sibling_symbols (sym, gfc_current_ns);
2277 /* Or refer to any of its alternate entry points. */
2278 for (el = gfc_current_ns->entries; el; el = el->next)
2279 gfc_fixup_sibling_symbols (el->sym, gfc_current_ns);
2281 gfc_current_ns->code = s2.head;
2282 gfc_current_ns = parent_ns;
2287 /* These statements are associated with the end of the host
2289 case ST_END_FUNCTION:
2291 case ST_END_PROGRAM:
2292 case ST_END_SUBROUTINE:
2293 accept_statement (st);
2297 gfc_error ("Unexpected %s statement in CONTAINS section at %C",
2298 gfc_ascii_statement (st));
2299 reject_statement ();
2303 while (st != ST_END_FUNCTION && st != ST_END_SUBROUTINE
2304 && st != ST_END_MODULE && st != ST_END_PROGRAM);
2306 /* The first namespace in the list is guaranteed to not have
2307 anything (worthwhile) in it. */
2309 gfc_current_ns = parent_ns;
2311 ns = gfc_current_ns->contained;
2312 gfc_current_ns->contained = ns->sibling;
2313 gfc_free_namespace (ns);
2319 /* Parse a PROGRAM, SUBROUTINE or FUNCTION unit. */
2322 parse_progunit (gfc_statement st)
2327 st = parse_spec (st);
2337 accept_statement (st);
2347 st = parse_executable (st);
2358 accept_statement (st);
2365 unexpected_statement (st);
2366 reject_statement ();
2367 st = next_statement ();
2373 for (p = gfc_state_stack; p; p = p->previous)
2374 if (p->state == COMP_CONTAINS)
2377 if (gfc_find_state (COMP_MODULE) == SUCCESS)
2382 gfc_error ("CONTAINS statement at %C is already in a contained "
2384 st = next_statement ();
2388 parse_contained (0);
2391 gfc_current_ns->code = gfc_state_stack->head;
2395 /* Come here to complain about a global symbol already in use as
2399 global_used (gfc_gsymbol *sym, locus *where)
2404 where = &gfc_current_locus;
2414 case GSYM_SUBROUTINE:
2415 name = "SUBROUTINE";
2420 case GSYM_BLOCK_DATA:
2421 name = "BLOCK DATA";
2427 gfc_internal_error ("gfc_gsymbol_type(): Bad type");
2431 gfc_error("Global name '%s' at %L is already being used as a %s at %L",
2432 gfc_new_block->name, where, name, &sym->where);
2436 /* Parse a block data program unit. */
2439 parse_block_data (void)
2442 static locus blank_locus;
2443 static int blank_block=0;
2446 gfc_current_ns->proc_name = gfc_new_block;
2447 gfc_current_ns->is_block_data = 1;
2449 if (gfc_new_block == NULL)
2452 gfc_error ("Blank BLOCK DATA at %C conflicts with "
2453 "prior BLOCK DATA at %L", &blank_locus);
2457 blank_locus = gfc_current_locus;
2462 s = gfc_get_gsymbol (gfc_new_block->name);
2463 if (s->type != GSYM_UNKNOWN)
2464 global_used(s, NULL);
2467 s->type = GSYM_BLOCK_DATA;
2468 s->where = gfc_current_locus;
2472 st = parse_spec (ST_NONE);
2474 while (st != ST_END_BLOCK_DATA)
2476 gfc_error ("Unexpected %s statement in BLOCK DATA at %C",
2477 gfc_ascii_statement (st));
2478 reject_statement ();
2479 st = next_statement ();
2484 /* Parse a module subprogram. */
2492 s = gfc_get_gsymbol (gfc_new_block->name);
2493 if (s->type != GSYM_UNKNOWN)
2494 global_used(s, NULL);
2497 s->type = GSYM_MODULE;
2498 s->where = gfc_current_locus;
2501 st = parse_spec (ST_NONE);
2510 parse_contained (1);
2514 accept_statement (st);
2518 gfc_error ("Unexpected %s statement in MODULE at %C",
2519 gfc_ascii_statement (st));
2521 reject_statement ();
2522 st = next_statement ();
2528 /* Add a procedure name to the global symbol table. */
2531 add_global_procedure (int sub)
2535 s = gfc_get_gsymbol(gfc_new_block->name);
2537 if (s->type != GSYM_UNKNOWN)
2538 global_used(s, NULL);
2541 s->type = sub ? GSYM_SUBROUTINE : GSYM_FUNCTION;
2542 s->where = gfc_current_locus;
2547 /* Add a program to the global symbol table. */
2550 add_global_program (void)
2554 if (gfc_new_block == NULL)
2556 s = gfc_get_gsymbol (gfc_new_block->name);
2558 if (s->type != GSYM_UNKNOWN)
2559 global_used(s, NULL);
2562 s->type = GSYM_PROGRAM;
2563 s->where = gfc_current_locus;
2568 /* Top level parser. */
2571 gfc_parse_file (void)
2573 int seen_program, errors_before, errors;
2574 gfc_state_data top, s;
2578 top.state = COMP_NONE;
2580 top.previous = NULL;
2581 top.head = top.tail = NULL;
2582 top.do_variable = NULL;
2584 gfc_state_stack = ⊤
2586 gfc_clear_new_st ();
2588 gfc_statement_label = NULL;
2590 if (setjmp (eof_buf))
2591 return FAILURE; /* Come here on unexpected EOF */
2595 /* Exit early for empty files. */
2601 st = next_statement ();
2610 goto duplicate_main;
2612 prog_locus = gfc_current_locus;
2614 push_state (&s, COMP_PROGRAM, gfc_new_block);
2615 main_program_symbol(gfc_current_ns);
2616 accept_statement (st);
2617 add_global_program ();
2618 parse_progunit (ST_NONE);
2622 add_global_procedure (1);
2623 push_state (&s, COMP_SUBROUTINE, gfc_new_block);
2624 accept_statement (st);
2625 parse_progunit (ST_NONE);
2629 add_global_procedure (0);
2630 push_state (&s, COMP_FUNCTION, gfc_new_block);
2631 accept_statement (st);
2632 parse_progunit (ST_NONE);
2636 push_state (&s, COMP_BLOCK_DATA, gfc_new_block);
2637 accept_statement (st);
2638 parse_block_data ();
2642 push_state (&s, COMP_MODULE, gfc_new_block);
2643 accept_statement (st);
2645 gfc_get_errors (NULL, &errors_before);
2649 /* Anything else starts a nameless main program block. */
2652 goto duplicate_main;
2654 prog_locus = gfc_current_locus;
2656 push_state (&s, COMP_PROGRAM, gfc_new_block);
2657 main_program_symbol(gfc_current_ns);
2658 parse_progunit (st);
2662 gfc_current_ns->code = s.head;
2664 gfc_resolve (gfc_current_ns);
2666 /* Dump the parse tree if requested. */
2667 if (gfc_option.verbose)
2668 gfc_show_namespace (gfc_current_ns);
2670 gfc_get_errors (NULL, &errors);
2671 if (s.state == COMP_MODULE)
2673 gfc_dump_module (s.sym->name, errors_before == errors);
2674 if (errors == 0 && ! gfc_option.flag_no_backend)
2675 gfc_generate_module_code (gfc_current_ns);
2679 if (errors == 0 && ! gfc_option.flag_no_backend)
2680 gfc_generate_code (gfc_current_ns);
2691 /* If we see a duplicate main program, shut down. If the second
2692 instance is an implied main program, ie data decls or executable
2693 statements, we're in for lots of errors. */
2694 gfc_error ("Two main PROGRAMs at %L and %C", &prog_locus);
2695 reject_statement ();