1/* Translation of constants
2 Copyright (C) 2002-2017 Free Software Foundation, Inc.
3 Contributed by Paul Brook
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3. If not see
19<http://www.gnu.org/licenses/>. */
20
21/* trans-const.c -- convert constant values */
22
23#include "config.h"
24#include "system.h"
25#include "coretypes.h"
26#include "tree.h"
27#include "gfortran.h"
28#include "trans.h"
29#include "diagnostic-core.h" /* For fatal_error. */
30#include "fold-const.h"
31#include "stor-layout.h"
32#include "realmpfr.h"
33#include "trans-const.h"
34#include "trans-types.h"
35#include "target-memory.h"
36
37tree gfc_rank_cst[GFC_MAX_DIMENSIONS + 1];
38
39/* Build a constant with given type from an int_cst. */
40
41tree
42gfc_build_const (tree type, tree intval)
43{
44 tree val;
45 tree zero;
46
47 switch (TREE_CODE (type))
48 {
49 case INTEGER_TYPE:
50 val = convert (type, intval);
51 break;
52
53 case REAL_TYPE:
54 val = build_real_from_int_cst (type, intval);
55 break;
56
57 case COMPLEX_TYPE:
58 val = build_real_from_int_cst (TREE_TYPE (type), intval);
59 zero = build_real_from_int_cst (TREE_TYPE (type), integer_zero_node);
60 val = build_complex (type, val, zero);
61 break;
62
63 default:
64 gcc_unreachable ();
65 }
66 return val;
67}
68
69/* Build a string constant with C char type. */
70
71tree
72gfc_build_string_const (int length, const char *s)
73{
74 tree str;
75 tree len;
76
77 str = build_string (length, s);
78 len = size_int (length);
79 TREE_TYPE (str) =
80 build_array_type (gfc_character1_type_node,
81 build_range_type (gfc_charlen_type_node,
82 size_one_node, len));
83 TYPE_STRING_FLAG (TREE_TYPE (str)) = 1;
84 return str;
85}
86
87
88/* Build a string constant with a type given by its kind; take care of
89 non-default character kinds. */
90
91tree
92gfc_build_wide_string_const (int kind, int length, const gfc_char_t *string)
93{
94 int i;
95 tree str, len;
96 size_t size;
97 char *s;
98
99 i = gfc_validate_kind (BT_CHARACTER, kind, false);
100 size = length * gfc_character_kinds[i].bit_size / 8;
101
102 s = XCNEWVAR (char, size);
103 gfc_encode_character (kind, length, string, (unsigned char *) s, size);
104
105 str = build_string (size, s);
106 free (s);
107
108 len = size_int (length);
109 TREE_TYPE (str) =
110 build_array_type (gfc_get_char_type (kind),
111 build_range_type (gfc_charlen_type_node,
112 size_one_node, len));
113 TYPE_STRING_FLAG (TREE_TYPE (str)) = 1;
114 return str;
115}
116
117
118/* Build a Fortran character constant from a zero-terminated string.
119 There a two version of this function, one that translates the string
120 and one that doesn't. */
121tree
122gfc_build_cstring_const (const char *string)
123{
124 return gfc_build_string_const (strlen (string) + 1, string);
125}
126
127tree
128gfc_build_localized_cstring_const (const char *msgid)
129{
130 const char *localized = _(msgid);
131 return gfc_build_string_const (strlen (localized) + 1, localized);
132}
133
134
135/* Return a string constant with the given length. Used for static
136 initializers. The constant will be padded or truncated to match
137 length. */
138
139tree
140gfc_conv_string_init (tree length, gfc_expr * expr)
141{
142 gfc_char_t *s;
143 HOST_WIDE_INT len;
144 int slen;
145 tree str;
146 bool free_s = false;
147
148 gcc_assert (expr->expr_type == EXPR_CONSTANT);
149 gcc_assert (expr->ts.type == BT_CHARACTER);
150 gcc_assert (tree_fits_uhwi_p (length));
151
152 len = TREE_INT_CST_LOW (length);
153 slen = expr->value.character.length;
154
155 if (len > slen)
156 {
157 s = gfc_get_wide_string (len);
158 memcpy (s, expr->value.character.string, slen * sizeof (gfc_char_t));
159 gfc_wide_memset (&s[slen], ' ', len - slen);
160 free_s = true;
161 }
162 else
163 s = expr->value.character.string;
164
165 str = gfc_build_wide_string_const (expr->ts.kind, len, s);
166
167 if (free_s)
168 free (s);
169
170 return str;
171}
172
173
174/* Create a tree node for the string length if it is constant. */
175
176void
177gfc_conv_const_charlen (gfc_charlen * cl)
178{
179 if (!cl || cl->backend_decl)
180 return;
181
182 if (cl->length && cl->length->expr_type == EXPR_CONSTANT)
183 {
184 cl->backend_decl = gfc_conv_mpz_to_tree (cl->length->value.integer,
185 cl->length->ts.kind);
186 cl->backend_decl = fold_convert (gfc_charlen_type_node,
187 cl->backend_decl);
188 }
189}
190
191void
192gfc_init_constants (void)
193{
194 int n;
195
196 for (n = 0; n <= GFC_MAX_DIMENSIONS; n++)
197 gfc_rank_cst[n] = build_int_cst (gfc_array_index_type, n);
198}
199
200/* Converts a GMP integer into a backend tree node. */
201
202tree
203gfc_conv_mpz_to_tree (mpz_t i, int kind)
204{
205 wide_int val = wi::from_mpz (gfc_get_int_type (kind), i, true);
206 return wide_int_to_tree (gfc_get_int_type (kind), val);
207}
208
209/* Converts a backend tree into a GMP integer. */
210
211void
212gfc_conv_tree_to_mpz (mpz_t i, tree source)
213{
214 wi::to_mpz (wi::to_wide (source), i, TYPE_SIGN (TREE_TYPE (source)));
215}
216
217/* Converts a real constant into backend form. */
218
219tree
220gfc_conv_mpfr_to_tree (mpfr_t f, int kind, int is_snan)
221{
222 tree type;
223 int n;
224 REAL_VALUE_TYPE real;
225
226 n = gfc_validate_kind (BT_REAL, kind, false);
227 gcc_assert (gfc_real_kinds[n].radix == 2);
228
229 type = gfc_get_real_type (kind);
230 if (mpfr_nan_p (f) && is_snan)
231 real_from_string (&real, "SNaN");
232 else
233 real_from_mpfr (&real, f, type, GFC_RND_MODE);
234
235 return build_real (type, real);
236}
237
238/* Returns a real constant that is +Infinity if the target
239 supports infinities for this floating-point mode, and
240 +HUGE_VAL otherwise (the largest representable number). */
241
242tree
243gfc_build_inf_or_huge (tree type, int kind)
244{
245 if (HONOR_INFINITIES (TYPE_MODE (type)))
246 {
247 REAL_VALUE_TYPE real;
248 real_inf (&real);
249 return build_real (type, real);
250 }
251 else
252 {
253 int k = gfc_validate_kind (BT_REAL, kind, false);
254 return gfc_conv_mpfr_to_tree (gfc_real_kinds[k].huge, kind, 0);
255 }
256}
257
258/* Returns a floating-point NaN of a given type. */
259
260tree
261gfc_build_nan (tree type, const char *str)
262{
263 REAL_VALUE_TYPE real;
264 real_nan (&real, str, 1, TYPE_MODE (type));
265 return build_real (type, real);
266}
267
268/* Converts a backend tree into a real constant. */
269
270void
271gfc_conv_tree_to_mpfr (mpfr_ptr f, tree source)
272{
273 mpfr_from_real (f, TREE_REAL_CST_PTR (source), GFC_RND_MODE);
274}
275
276/* Translate any literal constant to a tree. Constants never have
277 pre or post chains. Character literal constants are special
278 special because they have a value and a length, so they cannot be
279 returned as a single tree. It is up to the caller to set the
280 length somewhere if necessary.
281
282 Returns the translated constant, or aborts if it gets a type it
283 can't handle. */
284
285tree
286gfc_conv_constant_to_tree (gfc_expr * expr)
287{
288 tree res;
289
290 gcc_assert (expr->expr_type == EXPR_CONSTANT);
291
292 /* If it is has a prescribed memory representation, we build a string
293 constant and VIEW_CONVERT to its type. */
294
295 switch (expr->ts.type)
296 {
297 case BT_INTEGER:
298 if (expr->representation.string)
299 return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
300 gfc_get_int_type (expr->ts.kind),
301 gfc_build_string_const (expr->representation.length,
302 expr->representation.string));
303 else
304 return gfc_conv_mpz_to_tree (expr->value.integer, expr->ts.kind);
305
306 case BT_REAL:
307 if (expr->representation.string)
308 return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
309 gfc_get_real_type (expr->ts.kind),
310 gfc_build_string_const (expr->representation.length,
311 expr->representation.string));
312 else
313 return gfc_conv_mpfr_to_tree (expr->value.real, expr->ts.kind, expr->is_snan);
314
315 case BT_LOGICAL:
316 if (expr->representation.string)
317 {
318 tree tmp = fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
319 gfc_get_int_type (expr->ts.kind),
320 gfc_build_string_const (expr->representation.length,
321 expr->representation.string));
322 if (!integer_zerop (tmp) && !integer_onep (tmp))
323 gfc_warning (0, "Assigning value other than 0 or 1 to LOGICAL"
324 " has undefined result at %L", &expr->where);
325 return fold_convert (gfc_get_logical_type (expr->ts.kind), tmp);
326 }
327 else
328 return build_int_cst (gfc_get_logical_type (expr->ts.kind),
329 expr->value.logical);
330
331 case BT_COMPLEX:
332 if (expr->representation.string)
333 return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
334 gfc_get_complex_type (expr->ts.kind),
335 gfc_build_string_const (expr->representation.length,
336 expr->representation.string));
337 else
338 {
339 tree real = gfc_conv_mpfr_to_tree (mpc_realref (expr->value.complex),
340 expr->ts.kind, expr->is_snan);
341 tree imag = gfc_conv_mpfr_to_tree (mpc_imagref (expr->value.complex),
342 expr->ts.kind, expr->is_snan);
343
344 return build_complex (gfc_typenode_for_spec (&expr->ts),
345 real, imag);
346 }
347
348 case BT_CHARACTER:
349 res = gfc_build_wide_string_const (expr->ts.kind,
350 expr->value.character.length,
351 expr->value.character.string);
352 return res;
353
354 case BT_HOLLERITH:
355 return gfc_build_string_const (expr->representation.length,
356 expr->representation.string);
357
358 default:
359 fatal_error (input_location,
360 "gfc_conv_constant_to_tree(): invalid type: %s",
361 gfc_typename (&expr->ts));
362 }
363}
364
365
366/* Like gfc_conv_constant_to_tree, but for a simplified expression.
367 We can handle character literal constants here as well. */
368
369void
370gfc_conv_constant (gfc_se * se, gfc_expr * expr)
371{
372 gfc_ss *ss;
373
374 /* We may be receiving an expression for C_NULL_PTR or C_NULL_FUNPTR. If
375 so, the expr_type will not yet be an EXPR_CONSTANT. We need to make
376 it so here. */
377 if (expr->ts.type == BT_DERIVED && expr->ts.u.derived
378 && expr->ts.u.derived->attr.is_iso_c)
379 {
380 if (expr->symtree->n.sym->intmod_sym_id == ISOCBINDING_NULL_PTR
381 || expr->symtree->n.sym->intmod_sym_id == ISOCBINDING_NULL_FUNPTR)
382 {
383 /* Create a new EXPR_CONSTANT expression for our local uses. */
384 expr = gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
385 }
386 }
387
388 if (expr->expr_type != EXPR_CONSTANT)
389 {
390 gfc_expr *e = gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
391 gfc_error ("non-constant initialization expression at %L", &expr->where);
392 se->expr = gfc_conv_constant_to_tree (e);
393 return;
394 }
395
396 ss = se->ss;
397 if (ss != NULL)
398 {
399 gfc_ss_info *ss_info;
400
401 ss_info = ss->info;
402 gcc_assert (ss != gfc_ss_terminator);
403 gcc_assert (ss_info->type == GFC_SS_SCALAR);
404 gcc_assert (ss_info->expr == expr);
405
406 se->expr = ss_info->data.scalar.value;
407 se->string_length = ss_info->string_length;
408 gfc_advance_se_ss_chain (se);
409 return;
410 }
411
412 /* Translate the constant and put it in the simplifier structure. */
413 se->expr = gfc_conv_constant_to_tree (expr);
414
415 /* If this is a CHARACTER string, set its length in the simplifier
416 structure, too. */
417 if (expr->ts.type == BT_CHARACTER)
418 se->string_length = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (se->expr)));
419}
420