2013-12-29 Janus Weil <janus@gcc.gnu.org>
[official-gcc.git] / gcc / fortran / trans-const.c
blobf5a2b18ecba1f24426ae46feb526ab0a1ee175e6
1 /* Translation of constants
2 Copyright (C) 2002-2013 Free Software Foundation, Inc.
3 Contributed by Paul Brook
5 This file is part of GCC.
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 3, or (at your option) any later
10 version.
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.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* trans-const.c -- convert constant values */
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tree.h"
27 #include "stor-layout.h"
28 #include "realmpfr.h"
29 #include "diagnostic-core.h" /* For fatal_error. */
30 #include "double-int.h"
31 #include "gfortran.h"
32 #include "trans.h"
33 #include "trans-const.h"
34 #include "trans-types.h"
35 #include "target-memory.h"
37 tree gfc_rank_cst[GFC_MAX_DIMENSIONS + 1];
39 /* Build a constant with given type from an int_cst. */
41 tree
42 gfc_build_const (tree type, tree intval)
44 tree val;
45 tree zero;
47 switch (TREE_CODE (type))
49 case INTEGER_TYPE:
50 val = convert (type, intval);
51 break;
53 case REAL_TYPE:
54 val = build_real_from_int_cst (type, intval);
55 break;
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;
63 default:
64 gcc_unreachable ();
66 return val;
69 /* Build a string constant with C char type. */
71 tree
72 gfc_build_string_const (int length, const char *s)
74 tree str;
75 tree len;
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 return str;
87 /* Build a string constant with a type given by its kind; take care of
88 non-default character kinds. */
90 tree
91 gfc_build_wide_string_const (int kind, int length, const gfc_char_t *string)
93 int i;
94 tree str, len;
95 size_t size;
96 char *s;
98 i = gfc_validate_kind (BT_CHARACTER, kind, false);
99 size = length * gfc_character_kinds[i].bit_size / 8;
101 s = XCNEWVAR (char, size);
102 gfc_encode_character (kind, length, string, (unsigned char *) s, size);
104 str = build_string (size, s);
105 free (s);
107 len = size_int (length);
108 TREE_TYPE (str) =
109 build_array_type (gfc_get_char_type (kind),
110 build_range_type (gfc_charlen_type_node,
111 size_one_node, len));
112 return str;
116 /* Build a Fortran character constant from a zero-terminated string.
117 There a two version of this function, one that translates the string
118 and one that doesn't. */
119 tree
120 gfc_build_cstring_const (const char *string)
122 return gfc_build_string_const (strlen (string) + 1, string);
125 tree
126 gfc_build_localized_cstring_const (const char *msgid)
128 const char *localized = _(msgid);
129 return gfc_build_string_const (strlen (localized) + 1, localized);
133 /* Return a string constant with the given length. Used for static
134 initializers. The constant will be padded or truncated to match
135 length. */
137 tree
138 gfc_conv_string_init (tree length, gfc_expr * expr)
140 gfc_char_t *s;
141 HOST_WIDE_INT len;
142 int slen;
143 tree str;
144 bool free_s = false;
146 gcc_assert (expr->expr_type == EXPR_CONSTANT);
147 gcc_assert (expr->ts.type == BT_CHARACTER);
148 gcc_assert (INTEGER_CST_P (length));
149 gcc_assert (TREE_INT_CST_HIGH (length) == 0);
151 len = TREE_INT_CST_LOW (length);
152 slen = expr->value.character.length;
154 if (len > slen)
156 s = gfc_get_wide_string (len);
157 memcpy (s, expr->value.character.string, slen * sizeof (gfc_char_t));
158 gfc_wide_memset (&s[slen], ' ', len - slen);
159 free_s = true;
161 else
162 s = expr->value.character.string;
164 str = gfc_build_wide_string_const (expr->ts.kind, len, s);
166 if (free_s)
167 free (s);
169 return str;
173 /* Create a tree node for the string length if it is constant. */
175 void
176 gfc_conv_const_charlen (gfc_charlen * cl)
178 if (!cl || cl->backend_decl)
179 return;
181 if (cl->length && cl->length->expr_type == EXPR_CONSTANT)
183 cl->backend_decl = gfc_conv_mpz_to_tree (cl->length->value.integer,
184 cl->length->ts.kind);
185 cl->backend_decl = fold_convert (gfc_charlen_type_node,
186 cl->backend_decl);
190 void
191 gfc_init_constants (void)
193 int n;
195 for (n = 0; n <= GFC_MAX_DIMENSIONS; n++)
196 gfc_rank_cst[n] = build_int_cst (gfc_array_index_type, n);
199 /* Converts a GMP integer into a backend tree node. */
201 tree
202 gfc_conv_mpz_to_tree (mpz_t i, int kind)
204 double_int val = mpz_get_double_int (gfc_get_int_type (kind), i, true);
205 return double_int_to_tree (gfc_get_int_type (kind), val);
208 /* Converts a backend tree into a GMP integer. */
210 void
211 gfc_conv_tree_to_mpz (mpz_t i, tree source)
213 double_int val = tree_to_double_int (source);
214 mpz_set_double_int (i, val, TYPE_UNSIGNED (TREE_TYPE (source)));
217 /* Converts a real constant into backend form. */
219 tree
220 gfc_conv_mpfr_to_tree (mpfr_t f, int kind, int is_snan)
222 tree type;
223 int n;
224 REAL_VALUE_TYPE real;
226 n = gfc_validate_kind (BT_REAL, kind, false);
227 gcc_assert (gfc_real_kinds[n].radix == 2);
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);
235 return build_real (type, real);
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). */
242 tree
243 gfc_build_inf_or_huge (tree type, int kind)
245 if (HONOR_INFINITIES (TYPE_MODE (type)))
247 REAL_VALUE_TYPE real;
248 real_inf (&real);
249 return build_real (type, real);
251 else
253 int k = gfc_validate_kind (BT_REAL, kind, false);
254 return gfc_conv_mpfr_to_tree (gfc_real_kinds[k].huge, kind, 0);
258 /* Converts a backend tree into a real constant. */
260 void
261 gfc_conv_tree_to_mpfr (mpfr_ptr f, tree source)
263 mpfr_from_real (f, TREE_REAL_CST_PTR (source), GFC_RND_MODE);
266 /* Translate any literal constant to a tree. Constants never have
267 pre or post chains. Character literal constants are special
268 special because they have a value and a length, so they cannot be
269 returned as a single tree. It is up to the caller to set the
270 length somewhere if necessary.
272 Returns the translated constant, or aborts if it gets a type it
273 can't handle. */
275 tree
276 gfc_conv_constant_to_tree (gfc_expr * expr)
278 tree res;
280 gcc_assert (expr->expr_type == EXPR_CONSTANT);
282 /* If it is has a prescribed memory representation, we build a string
283 constant and VIEW_CONVERT to its type. */
285 switch (expr->ts.type)
287 case BT_INTEGER:
288 if (expr->representation.string)
289 return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
290 gfc_get_int_type (expr->ts.kind),
291 gfc_build_string_const (expr->representation.length,
292 expr->representation.string));
293 else
294 return gfc_conv_mpz_to_tree (expr->value.integer, expr->ts.kind);
296 case BT_REAL:
297 if (expr->representation.string)
298 return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
299 gfc_get_real_type (expr->ts.kind),
300 gfc_build_string_const (expr->representation.length,
301 expr->representation.string));
302 else
303 return gfc_conv_mpfr_to_tree (expr->value.real, expr->ts.kind, expr->is_snan);
305 case BT_LOGICAL:
306 if (expr->representation.string)
308 tree tmp = fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
309 gfc_get_int_type (expr->ts.kind),
310 gfc_build_string_const (expr->representation.length,
311 expr->representation.string));
312 if (!integer_zerop (tmp) && !integer_onep (tmp))
313 gfc_warning ("Assigning value other than 0 or 1 to LOGICAL"
314 " has undefined result at %L", &expr->where);
315 return fold_convert (gfc_get_logical_type (expr->ts.kind), tmp);
317 else
318 return build_int_cst (gfc_get_logical_type (expr->ts.kind),
319 expr->value.logical);
321 case BT_COMPLEX:
322 if (expr->representation.string)
323 return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
324 gfc_get_complex_type (expr->ts.kind),
325 gfc_build_string_const (expr->representation.length,
326 expr->representation.string));
327 else
329 tree real = gfc_conv_mpfr_to_tree (mpc_realref (expr->value.complex),
330 expr->ts.kind, expr->is_snan);
331 tree imag = gfc_conv_mpfr_to_tree (mpc_imagref (expr->value.complex),
332 expr->ts.kind, expr->is_snan);
334 return build_complex (gfc_typenode_for_spec (&expr->ts),
335 real, imag);
338 case BT_CHARACTER:
339 res = gfc_build_wide_string_const (expr->ts.kind,
340 expr->value.character.length,
341 expr->value.character.string);
342 return res;
344 case BT_HOLLERITH:
345 return gfc_build_string_const (expr->representation.length,
346 expr->representation.string);
348 default:
349 fatal_error ("gfc_conv_constant_to_tree(): invalid type: %s",
350 gfc_typename (&expr->ts));
355 /* Like gfc_conv_constant_to_tree, but for a simplified expression.
356 We can handle character literal constants here as well. */
358 void
359 gfc_conv_constant (gfc_se * se, gfc_expr * expr)
361 gfc_ss *ss;
363 /* We may be receiving an expression for C_NULL_PTR or C_NULL_FUNPTR. If
364 so, the expr_type will not yet be an EXPR_CONSTANT. We need to make
365 it so here. */
366 if (expr->ts.type == BT_DERIVED && expr->ts.u.derived
367 && expr->ts.u.derived->attr.is_iso_c)
369 if (expr->symtree->n.sym->intmod_sym_id == ISOCBINDING_NULL_PTR
370 || expr->symtree->n.sym->intmod_sym_id == ISOCBINDING_NULL_FUNPTR)
372 /* Create a new EXPR_CONSTANT expression for our local uses. */
373 expr = gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
377 if (expr->expr_type != EXPR_CONSTANT)
379 gfc_expr *e = gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
380 gfc_error ("non-constant initialization expression at %L", &expr->where);
381 se->expr = gfc_conv_constant_to_tree (e);
382 return;
385 ss = se->ss;
386 if (ss != NULL)
388 gfc_ss_info *ss_info;
390 ss_info = ss->info;
391 gcc_assert (ss != gfc_ss_terminator);
392 gcc_assert (ss_info->type == GFC_SS_SCALAR);
393 gcc_assert (ss_info->expr == expr);
395 se->expr = ss_info->data.scalar.value;
396 se->string_length = ss_info->string_length;
397 gfc_advance_se_ss_chain (se);
398 return;
401 /* Translate the constant and put it in the simplifier structure. */
402 se->expr = gfc_conv_constant_to_tree (expr);
404 /* If this is a CHARACTER string, set its length in the simplifier
405 structure, too. */
406 if (expr->ts.type == BT_CHARACTER)
407 se->string_length = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (se->expr)));