backport: trans-decl.c (create_function_arglist): Handle dummy functions.
[gcc.git] / gcc / fortran / trans.h
1 /* Header for code translation functions
2 Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
3 Contributed by Paul Brook
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
20 02110-1301, USA. */
21
22 #ifndef GFC_TRANS_H
23 #define GFC_TRANS_H
24
25 /* Mangled symbols take the form __module__name. */
26 #define GFC_MAX_MANGLED_SYMBOL_LEN (GFC_MAX_SYMBOL_LEN*2+4)
27
28 /* Struct for holding a block of statements. It should be treated as an
29 opaque entity and not modified directly. This allows us to change the
30 underlying representation of statement lists. */
31 typedef struct
32 {
33 tree head;
34 unsigned int has_scope:1;
35 }
36 stmtblock_t;
37
38 /* a simplified expression */
39 typedef struct gfc_se
40 {
41 /* Code blocks to be executed before and after using the value. */
42 stmtblock_t pre;
43 stmtblock_t post;
44
45 /* the result of the expression */
46 tree expr;
47
48 /* The length of a character string value. */
49 tree string_length;
50
51 /* If set gfc_conv_variable will return an expression for the array
52 descriptor. When set, want_pointer should also be set.
53 If not set scalarizing variables will be substituted. */
54 unsigned descriptor_only:1;
55
56 /* When this is set gfc_conv_expr returns the address of a variable. Only
57 applies to EXPR_VARIABLE nodes.
58 Also used by gfc_conv_array_parameter. When set this indicates a pointer
59 to the descriptor should be returned, rather than the descriptor itself.
60 */
61 unsigned want_pointer:1;
62
63 /* An array function call returning without a temporary. Also used for array
64 pointer assignments. */
65 unsigned direct_byref:1;
66
67 /* Ignore absent optional arguments. Used for some intrinsics. */
68 unsigned ignore_optional:1;
69
70 /* Scalarization parameters. */
71 struct gfc_se *parent;
72 struct gfc_ss *ss;
73 struct gfc_loopinfo *loop;
74 }
75 gfc_se;
76
77
78 /* Scalarization State chain. Created by walking an expression tree before
79 creating the scalarization loops. Then passed as part of a gfc_se structure
80 to translate the expression inside the loop. Note that these chains are
81 terminated by gfc_se_terminator, not NULL. A NULL pointer in a gfc_se
82 indicates to gfc_conv_* that this is a scalar expression.
83 Note that some member arrays correspond to scalarizer rank and others
84 are the variable rank. */
85
86 typedef struct gfc_ss_info
87 {
88 int dimen;
89 /* The ref that holds information on this section. */
90 gfc_ref *ref;
91 /* The descriptor of this array. */
92 tree descriptor;
93 /* holds the pointer to the data array. */
94 tree data;
95 /* To move some of the array index calculation out of the innermost loop. */
96 tree offset;
97 tree saved_offset;
98 tree stride0;
99 /* Holds the SS for a subscript. Indexed by actual dimension. */
100 struct gfc_ss *subscript[GFC_MAX_DIMENSIONS];
101
102 /* stride and delta are used to access this inside a scalarization loop.
103 start is used in the calculation of these. Indexed by scalarizer
104 dimension. */
105 tree start[GFC_MAX_DIMENSIONS];
106 tree stride[GFC_MAX_DIMENSIONS];
107 tree delta[GFC_MAX_DIMENSIONS];
108
109 /* Translation from scalarizer dimensions to actual dimensions.
110 actual = dim[scalarizer] */
111 int dim[GFC_MAX_DIMENSIONS];
112 }
113 gfc_ss_info;
114
115 typedef enum
116 {
117 /* A scalar value. This will be evaluated before entering the
118 scalarization loop. */
119 GFC_SS_SCALAR,
120
121 /* Like GFC_SS_SCALAR except it evaluates a pointer to the expression.
122 Used for elemental function parameters. */
123 GFC_SS_REFERENCE,
124
125 /* An array section. Scalarization indices will be substituted during
126 expression translation. */
127 GFC_SS_SECTION,
128
129 /* A non-elemental function call returning an array. The call is executed
130 before entering the scalarization loop, storing the result in a
131 temporary. This temporary is then used inside the scalarization loop.
132 Simple assignments, eg. a(:) = fn() are handles without a temporary
133 as a special case. */
134 GFC_SS_FUNCTION,
135
136 /* An array constructor. The current implementation is sub-optimal in
137 many cases. It allocated a temporary, assigns the values to it, then
138 uses this temporary inside the scalarization loop. */
139 GFC_SS_CONSTRUCTOR,
140
141 /* A vector subscript. The vector's descriptor is cached in the
142 "descriptor" field of the associated gfc_ss_info. */
143 GFC_SS_VECTOR,
144
145 /* A temporary array allocated by the scalarizer. Its rank can be less
146 than that of the assignment expression. */
147 GFC_SS_TEMP,
148
149 /* An intrinsic function call. Many intrinsic functions which map directly
150 to library calls are created as GFC_SS_FUNCTION nodes. */
151 GFC_SS_INTRINSIC,
152
153 /* A component of a derived type. */
154 GFC_SS_COMPONENT
155 }
156 gfc_ss_type;
157
158 /* SS structures can only belong to a single loopinfo. They must be added
159 otherwise they will not get freed. */
160 typedef struct gfc_ss
161 {
162 gfc_ss_type type;
163 gfc_expr *expr;
164 mpz_t *shape;
165 tree string_length;
166 union
167 {
168 /* If type is GFC_SS_SCALAR or GFC_SS_REFERENCE. */
169 struct
170 {
171 tree expr;
172 }
173 scalar;
174
175 /* GFC_SS_TEMP. */
176 struct
177 {
178 /* The rank of the temporary. May be less than the rank of the
179 assigned expression. */
180 int dimen;
181 tree type;
182 }
183 temp;
184 /* All other types. */
185 gfc_ss_info info;
186 }
187 data;
188
189 /* All the SS in a loop and linked through loop_chain. The SS for an
190 expression are linked by the next pointer. */
191 struct gfc_ss *loop_chain;
192 struct gfc_ss *next;
193
194 /* This is used by assignments requiring temporaries. The bits specify which
195 loops the terms appear in. This will be 1 for the RHS expressions,
196 2 for the LHS expressions, and 3(=1|2) for the temporary. */
197 unsigned useflags:2;
198 }
199 gfc_ss;
200 #define gfc_get_ss() gfc_getmem(sizeof(gfc_ss))
201
202 /* The contents of this aren't actually used. A NULL SS chain indicates a
203 scalar expression, so this pointer is used to terminate SS chains. */
204 extern gfc_ss * const gfc_ss_terminator;
205
206 /* Holds information about an expression while it is being scalarized. */
207 typedef struct gfc_loopinfo
208 {
209 stmtblock_t pre;
210 stmtblock_t post;
211
212 int dimen;
213
214 /* All the SS involved with this loop. */
215 gfc_ss *ss;
216 /* The SS describing the temporary used in an assignment. */
217 gfc_ss *temp_ss;
218
219 /* The scalarization loop index variables. */
220 tree loopvar[GFC_MAX_DIMENSIONS];
221
222 /* The bounds of the scalarization loops. */
223 tree from[GFC_MAX_DIMENSIONS];
224 tree to[GFC_MAX_DIMENSIONS];
225 gfc_ss *specloop[GFC_MAX_DIMENSIONS];
226
227 /* The code member contains the code for the body of the next outer loop. */
228 stmtblock_t code[GFC_MAX_DIMENSIONS];
229
230 /* Order in which the dimensions should be looped, innermost first. */
231 int order[GFC_MAX_DIMENSIONS];
232
233 /* The number of dimensions for which a temporary is used. */
234 int temp_dim;
235
236 /* If set we don't need the loop variables. */
237 unsigned array_parameter:1;
238 }
239 gfc_loopinfo;
240
241
242 /* Information about a symbol that has been shadowed by a temporary. */
243 typedef struct
244 {
245 symbol_attribute attr;
246 tree decl;
247 }
248 gfc_saved_var;
249
250
251 /* Advance the SS chain to the next term. */
252 void gfc_advance_se_ss_chain (gfc_se *);
253
254 /* Call this to initialize a gfc_se structure before use
255 first parameter is structure to initialize, second is
256 parent to get scalarization data from, or NULL. */
257 void gfc_init_se (gfc_se *, gfc_se *);
258
259 /* Create an artificial variable decl and add it to the current scope. */
260 tree gfc_create_var (tree, const char *);
261 /* Like above but doesn't add it to the current scope. */
262 tree gfc_create_var_np (tree, const char *);
263
264 /* Store the result of an expression in a temp variable so it can be used
265 repeatedly even if the original changes */
266 void gfc_make_safe_expr (gfc_se * se);
267
268 /* Makes sure se is suitable for passing as a function string parameter. */
269 void gfc_conv_string_parameter (gfc_se * se);
270
271 /* Compare two strings. */
272 tree gfc_build_compare_string (tree, tree, tree, tree);
273
274 /* Add an item to the end of TREE_LIST. */
275 tree gfc_chainon_list (tree, tree);
276
277 /* When using the gfc_conv_* make sure you understand what they do, i.e.
278 when a POST chain may be created, and what the returned expression may be
279 used for. Note that character strings have special handling. This
280 should not be a problem as most statements/operations only deal with
281 numeric/logical types. See the implementations in trans-expr.c
282 for details of the individual functions. */
283
284 void gfc_conv_expr (gfc_se * se, gfc_expr * expr);
285 void gfc_conv_expr_val (gfc_se * se, gfc_expr * expr);
286 void gfc_conv_expr_lhs (gfc_se * se, gfc_expr * expr);
287 void gfc_conv_expr_reference (gfc_se * se, gfc_expr *);
288 void gfc_conv_expr_type (gfc_se * se, gfc_expr *, tree);
289
290 /* Find the decl containing the auxiliary variables for assigned variables. */
291 void gfc_conv_label_variable (gfc_se * se, gfc_expr * expr);
292 /* If the value is not constant, Create a temporary and copy the value. */
293 tree gfc_evaluate_now (tree, stmtblock_t *);
294
295 /* Intrinsic function handling. */
296 void gfc_conv_intrinsic_function (gfc_se *, gfc_expr *);
297
298 /* Does an intrinsic map directly to an external library call. */
299 int gfc_is_intrinsic_libcall (gfc_expr *);
300
301 /* Also used to CALL subroutines. */
302 int gfc_conv_function_call (gfc_se *, gfc_symbol *, gfc_actual_arglist *);
303 /* gfc_trans_* shouldn't call push/poplevel, use gfc_push/pop_scope */
304
305 /* Generate code for a scalar assignment. */
306 tree gfc_trans_scalar_assign (gfc_se *, gfc_se *, bt);
307
308 /* Translate COMMON blocks. */
309 void gfc_trans_common (gfc_namespace *);
310
311 /* Translate a derived type constructor. */
312 void gfc_conv_structure (gfc_se *, gfc_expr *, int);
313
314 /* Return an expression which determines if a dummy parameter is present. */
315 tree gfc_conv_expr_present (gfc_symbol *);
316
317 /* Generate code to allocate a string temporary. */
318 tree gfc_conv_string_tmp (gfc_se *, tree, tree);
319 /* Get the string length variable belonging to an expression. */
320 tree gfc_get_expr_charlen (gfc_expr *);
321 /* Initialize a string length variable. */
322 void gfc_trans_init_string_length (gfc_charlen *, stmtblock_t *);
323 /* Ensure type sizes can be gimplified. */
324 void gfc_trans_vla_type_sizes (gfc_symbol *, stmtblock_t *);
325
326 /* Add an expression to the end of a block. */
327 void gfc_add_expr_to_block (stmtblock_t *, tree);
328 /* Add a block to the end of a block. */
329 void gfc_add_block_to_block (stmtblock_t *, stmtblock_t *);
330 /* Add a MODIFY_EXPR to a block. */
331 void gfc_add_modify_expr (stmtblock_t *, tree, tree);
332
333 /* Initialize a statement block. */
334 void gfc_init_block (stmtblock_t *);
335 /* Start a new statement block. Like gfc_init_block but also starts a new
336 variable scope. */
337 void gfc_start_block (stmtblock_t *);
338 /* Finish a statement block. Also closes the scope if the block was created
339 with gfc_start_block. */
340 tree gfc_finish_block (stmtblock_t *);
341 /* Merge the scope of a block with its parent. */
342 void gfc_merge_block_scope (stmtblock_t * block);
343
344 /* Return the backend label decl. */
345 tree gfc_get_label_decl (gfc_st_label *);
346
347 /* Return the decl for an external function. */
348 tree gfc_get_extern_function_decl (gfc_symbol *);
349
350 /* Return the decl for a function. */
351 tree gfc_get_function_decl (gfc_symbol *);
352
353 /* Build an ADDR_EXPR. */
354 tree gfc_build_addr_expr (tree, tree);
355
356 /* Build an ARRAY_REF. */
357 tree gfc_build_array_ref (tree, tree);
358
359 /* Creates a label. Decl is artificial if label_id == NULL_TREE. */
360 tree gfc_build_label_decl (tree);
361
362 /* Return the decl used to hold the function return value.
363 Do not use if the function has an explicit result variable. */
364 tree gfc_get_fake_result_decl (gfc_symbol *);
365
366 /* Get the return label for the current function. */
367 tree gfc_get_return_label (void);
368
369 /* Add a decl to the binding level for the current function. */
370 void gfc_add_decl_to_function (tree);
371
372 /* Make prototypes for runtime library functions. */
373 void gfc_build_builtin_function_decls (void);
374
375 /* Set the backend source location of a decl. */
376 void gfc_set_decl_location (tree, locus *);
377
378 /* Return the variable decl for a symbol. */
379 tree gfc_get_symbol_decl (gfc_symbol *);
380
381 /* Build a static initializer. */
382 tree gfc_conv_initializer (gfc_expr *, gfc_typespec *, tree, bool, bool);
383
384 /* Substitute a temporary variable in place of the real one. */
385 void gfc_shadow_sym (gfc_symbol *, tree, gfc_saved_var *);
386
387 /* Restore the original variable. */
388 void gfc_restore_sym (gfc_symbol *, gfc_saved_var *);
389
390 /* Returns true if a variable of specified size should go on the stack. */
391 int gfc_can_put_var_on_stack (tree);
392
393 /* Allocate the lang-specific part of a decl node. */
394 void gfc_allocate_lang_decl (tree);
395
396 /* Advance along a TREE_CHAIN. */
397 tree gfc_advance_chain (tree, int);
398
399 /* Create a decl for a function. */
400 void gfc_create_function_decl (gfc_namespace *);
401 /* Generate the code for a function. */
402 void gfc_generate_function_code (gfc_namespace *);
403 /* Output a BLOCK DATA program unit. */
404 void gfc_generate_block_data (gfc_namespace *);
405 /* Output a decl for a module variable. */
406 void gfc_generate_module_vars (gfc_namespace *);
407
408 /* Get and set the current location. */
409 void gfc_set_backend_locus (locus *);
410 void gfc_get_backend_locus (locus *);
411
412 /* Handle static constructor functions. */
413 extern GTY(()) tree gfc_static_ctors;
414 void gfc_generate_constructors (void);
415
416 /* Generate a runtime error check. */
417 void gfc_trans_runtime_check (tree, tree, stmtblock_t *);
418
419 /* Generate code for an assignment, includes scalarization. */
420 tree gfc_trans_assignment (gfc_expr *, gfc_expr *);
421
422 /* Generate code for a pointer assignment. */
423 tree gfc_trans_pointer_assignment (gfc_expr *, gfc_expr *);
424
425 /* Initialize function decls for library functions. */
426 void gfc_build_intrinsic_lib_fndecls (void);
427 /* Create function decls for IO library functions. */
428 void gfc_build_io_library_fndecls (void);
429 /* Build a function decl for a library function. */
430 tree gfc_build_library_function_decl (tree, tree, int, ...);
431
432 /* somewhere! */
433 tree pushdecl (tree);
434 tree pushdecl_top_level (tree);
435 void pushlevel (int);
436 tree poplevel (int, int, int);
437 tree getdecls (void);
438 tree gfc_truthvalue_conversion (tree);
439 tree builtin_function (const char *, tree, int, enum built_in_class,
440 const char *, tree);
441
442 /* Runtime library function decls. */
443 extern GTY(()) tree gfor_fndecl_internal_malloc;
444 extern GTY(()) tree gfor_fndecl_internal_malloc64;
445 extern GTY(()) tree gfor_fndecl_internal_realloc;
446 extern GTY(()) tree gfor_fndecl_internal_realloc64;
447 extern GTY(()) tree gfor_fndecl_internal_free;
448 extern GTY(()) tree gfor_fndecl_allocate;
449 extern GTY(()) tree gfor_fndecl_allocate64;
450 extern GTY(()) tree gfor_fndecl_deallocate;
451 extern GTY(()) tree gfor_fndecl_pause_numeric;
452 extern GTY(()) tree gfor_fndecl_pause_string;
453 extern GTY(()) tree gfor_fndecl_stop_numeric;
454 extern GTY(()) tree gfor_fndecl_stop_string;
455 extern GTY(()) tree gfor_fndecl_select_string;
456 extern GTY(()) tree gfor_fndecl_runtime_error;
457 extern GTY(()) tree gfor_fndecl_set_fpe;
458 extern GTY(()) tree gfor_fndecl_set_std;
459 extern GTY(()) tree gfor_fndecl_ttynam;
460 extern GTY(()) tree gfor_fndecl_ctime;
461 extern GTY(()) tree gfor_fndecl_fdate;
462 extern GTY(()) tree gfor_fndecl_in_pack;
463 extern GTY(()) tree gfor_fndecl_in_unpack;
464 extern GTY(()) tree gfor_fndecl_associated;
465
466 /* Math functions. Many other math functions are handled in
467 trans-intrinsic.c. */
468
469 typedef struct gfc_powdecl_list GTY(())
470 {
471 tree integer;
472 tree real;
473 tree cmplx;
474 }
475 gfc_powdecl_list;
476
477 extern GTY(()) gfc_powdecl_list gfor_fndecl_math_powi[4][3];
478 extern GTY(()) tree gfor_fndecl_math_cpowf;
479 extern GTY(()) tree gfor_fndecl_math_cpow;
480 extern GTY(()) tree gfor_fndecl_math_cpowl10;
481 extern GTY(()) tree gfor_fndecl_math_cpowl16;
482 extern GTY(()) tree gfor_fndecl_math_ishftc4;
483 extern GTY(()) tree gfor_fndecl_math_ishftc8;
484 extern GTY(()) tree gfor_fndecl_math_ishftc16;
485 extern GTY(()) tree gfor_fndecl_math_exponent4;
486 extern GTY(()) tree gfor_fndecl_math_exponent8;
487 extern GTY(()) tree gfor_fndecl_math_exponent10;
488 extern GTY(()) tree gfor_fndecl_math_exponent16;
489
490 /* String functions. */
491 extern GTY(()) tree gfor_fndecl_copy_string;
492 extern GTY(()) tree gfor_fndecl_compare_string;
493 extern GTY(()) tree gfor_fndecl_concat_string;
494 extern GTY(()) tree gfor_fndecl_string_len_trim;
495 extern GTY(()) tree gfor_fndecl_string_index;
496 extern GTY(()) tree gfor_fndecl_string_scan;
497 extern GTY(()) tree gfor_fndecl_string_verify;
498 extern GTY(()) tree gfor_fndecl_string_trim;
499 extern GTY(()) tree gfor_fndecl_string_repeat;
500 extern GTY(()) tree gfor_fndecl_adjustl;
501 extern GTY(()) tree gfor_fndecl_adjustr;
502
503 /* Other misc. runtime library functions. */
504 extern GTY(()) tree gfor_fndecl_size0;
505 extern GTY(()) tree gfor_fndecl_size1;
506 extern GTY(()) tree gfor_fndecl_iargc;
507
508 /* Implemented in FORTRAN. */
509 extern GTY(()) tree gfor_fndecl_si_kind;
510 extern GTY(()) tree gfor_fndecl_sr_kind;
511
512
513 /* True if node is an integer constant. */
514 #define INTEGER_CST_P(node) (TREE_CODE(node) == INTEGER_CST)
515
516 /* G95-specific declaration information. */
517
518 /* Array types only. */
519 struct lang_type GTY(())
520 {
521 int rank;
522 tree lbound[GFC_MAX_DIMENSIONS];
523 tree ubound[GFC_MAX_DIMENSIONS];
524 tree stride[GFC_MAX_DIMENSIONS];
525 tree size;
526 tree offset;
527 tree dtype;
528 tree dataptr_type;
529 };
530
531 struct lang_decl GTY(())
532 {
533 /* Dummy variables. */
534 tree saved_descriptor;
535 /* Assigned integer nodes. Stringlength is the IO format string's length.
536 Addr is the address of the string or the target label. Stringlength is
537 initialized to -2 and assigned to -1 when addr is assigned to the
538 address of target label. */
539 tree stringlen;
540 tree addr;
541 };
542
543
544 #define GFC_DECL_ASSIGN_ADDR(node) DECL_LANG_SPECIFIC(node)->addr
545 #define GFC_DECL_STRING_LEN(node) DECL_LANG_SPECIFIC(node)->stringlen
546 #define GFC_DECL_SAVED_DESCRIPTOR(node) \
547 (DECL_LANG_SPECIFIC(node)->saved_descriptor)
548 #define GFC_DECL_PACKED_ARRAY(node) DECL_LANG_FLAG_0(node)
549 #define GFC_DECL_PARTIAL_PACKED_ARRAY(node) DECL_LANG_FLAG_1(node)
550 #define GFC_DECL_ASSIGN(node) DECL_LANG_FLAG_2(node)
551
552 /* An array descriptor. */
553 #define GFC_DESCRIPTOR_TYPE_P(node) TYPE_LANG_FLAG_1(node)
554 /* An array without a descriptor. */
555 #define GFC_ARRAY_TYPE_P(node) TYPE_LANG_FLAG_2(node)
556 /* The GFC_TYPE_ARRAY_* members are present in both descriptor and
557 descriptorless array types. */
558 #define GFC_TYPE_ARRAY_LBOUND(node, dim) \
559 (TYPE_LANG_SPECIFIC(node)->lbound[dim])
560 #define GFC_TYPE_ARRAY_UBOUND(node, dim) \
561 (TYPE_LANG_SPECIFIC(node)->ubound[dim])
562 #define GFC_TYPE_ARRAY_STRIDE(node, dim) \
563 (TYPE_LANG_SPECIFIC(node)->stride[dim])
564 #define GFC_TYPE_ARRAY_RANK(node) (TYPE_LANG_SPECIFIC(node)->rank)
565 #define GFC_TYPE_ARRAY_SIZE(node) (TYPE_LANG_SPECIFIC(node)->size)
566 #define GFC_TYPE_ARRAY_OFFSET(node) (TYPE_LANG_SPECIFIC(node)->offset)
567 /* Code should use gfc_get_dtype instead of accesig this directly. It may
568 not be known when the type is created. */
569 #define GFC_TYPE_ARRAY_DTYPE(node) (TYPE_LANG_SPECIFIC(node)->dtype)
570 #define GFC_TYPE_ARRAY_DATAPTR_TYPE(node) \
571 (TYPE_LANG_SPECIFIC(node)->dataptr_type)
572
573 /* I changed this from sorry(...) because it should not return. */
574 /* TODO: Remove gfc_todo_error before releasing version 1.0. */
575 #define gfc_todo_error(args...) fatal_error("gfc_todo: Not Implemented: " args)
576
577 /* Build an expression with void type. */
578 #define build1_v(code, arg) build1(code, void_type_node, arg)
579 #define build2_v(code, arg1, arg2) build2(code, void_type_node, \
580 arg1, arg2)
581 #define build3_v(code, arg1, arg2, arg3) build3(code, void_type_node, \
582 arg1, arg2, arg3)
583
584 /* This group of functions allows a caller to evaluate an expression from
585 the callee's interface. It establishes a mapping between the interface's
586 dummy arguments and the caller's actual arguments, then applies that
587 mapping to a given gfc_expr.
588
589 You can initialize a mapping structure like so:
590
591 gfc_interface_mapping mapping;
592 ...
593 gfc_init_interface_mapping (&mapping);
594
595 You should then evaluate each actual argument into a temporary
596 gfc_se structure, here called "se", and map the result to the
597 dummy argument's symbol, here called "sym":
598
599 gfc_add_interface_mapping (&mapping, sym, &se);
600
601 After adding all mappings, you should call:
602
603 gfc_finish_interface_mapping (&mapping, pre, post);
604
605 where "pre" and "post" are statement blocks for initialization
606 and finalization code respectively. You can then evaluate an
607 interface expression "expr" as follows:
608
609 gfc_apply_interface_mapping (&mapping, se, expr);
610
611 Once you've evaluated all expressions, you should free
612 the mapping structure with:
613
614 gfc_free_interface_mapping (&mapping); */
615
616
617 /* This structure represents a mapping from OLD to NEW, where OLD is a
618 dummy argument symbol and NEW is a symbol that represents the value
619 of an actual argument. Mappings are linked together using NEXT
620 (in no particular order). */
621 typedef struct gfc_interface_sym_mapping
622 {
623 struct gfc_interface_sym_mapping *next;
624 gfc_symbol *old;
625 gfc_symtree *new;
626 }
627 gfc_interface_sym_mapping;
628
629
630 /* This structure is used by callers to evaluate an expression from
631 a callee's interface. */
632 typedef struct gfc_interface_mapping
633 {
634 /* Maps the interface's dummy arguments to the values that the caller
635 is passing. The whole list is owned by this gfc_interface_mapping. */
636 gfc_interface_sym_mapping *syms;
637
638 /* A list of gfc_charlens that were needed when creating copies of
639 expressions. The whole list is owned by this gfc_interface_mapping. */
640 gfc_charlen *charlens;
641 }
642 gfc_interface_mapping;
643
644 void gfc_init_interface_mapping (gfc_interface_mapping *);
645 void gfc_free_interface_mapping (gfc_interface_mapping *);
646 void gfc_add_interface_mapping (gfc_interface_mapping *,
647 gfc_symbol *, gfc_se *);
648 void gfc_finish_interface_mapping (gfc_interface_mapping *,
649 stmtblock_t *, stmtblock_t *);
650 void gfc_apply_interface_mapping (gfc_interface_mapping *,
651 gfc_se *, gfc_expr *);
652
653 #endif /* GFC_TRANS_H */