1/* Translation of constants
2   Copyright (C) 2002-2020 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 "options.h"
29#include "trans.h"
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 (size_t 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, size_t 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  gfc_charlen_t 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
210/* Convert a GMP integer into a tree node of type given by the type
211   argument.  */
212
213tree
214gfc_conv_mpz_to_tree_type (mpz_t i, const tree type)
215{
216  const wide_int val = wi::from_mpz (type, i, true);
217  return wide_int_to_tree (type, val);
218}
219
220
221/* Converts a backend tree into a GMP integer.  */
222
223void
224gfc_conv_tree_to_mpz (mpz_t i, tree source)
225{
226  wi::to_mpz (wi::to_wide (source), i, TYPE_SIGN (TREE_TYPE (source)));
227}
228
229/* Converts a real constant into backend form.  */
230
231tree
232gfc_conv_mpfr_to_tree (mpfr_t f, int kind, int is_snan)
233{
234  tree type;
235  int n;
236  REAL_VALUE_TYPE real;
237
238  n = gfc_validate_kind (BT_REAL, kind, false);
239  gcc_assert (gfc_real_kinds[n].radix == 2);
240
241  type = gfc_get_real_type (kind);
242  if (mpfr_nan_p (f) && is_snan)
243     real_from_string (&real, "SNaN");
244  else
245    real_from_mpfr (&real, f, type, GFC_RND_MODE);
246
247  return build_real (type, real);
248}
249
250/* Returns a real constant that is +Infinity if the target
251   supports infinities for this floating-point mode, and
252   +HUGE_VAL otherwise (the largest representable number).  */
253
254tree
255gfc_build_inf_or_huge (tree type, int kind)
256{
257  if (HONOR_INFINITIES (TYPE_MODE (type)))
258    {
259      REAL_VALUE_TYPE real;
260      real_inf (&real);
261      return build_real (type, real);
262    }
263  else
264    {
265      int k = gfc_validate_kind (BT_REAL, kind, false);
266      return gfc_conv_mpfr_to_tree (gfc_real_kinds[k].huge, kind, 0);
267    }
268}
269
270/* Returns a floating-point NaN of a given type.  */
271
272tree
273gfc_build_nan (tree type, const char *str)
274{
275  REAL_VALUE_TYPE real;
276  real_nan (&real, str, 1, TYPE_MODE (type));
277  return build_real (type, real);
278}
279
280/* Converts a backend tree into a real constant.  */
281
282void
283gfc_conv_tree_to_mpfr (mpfr_ptr f, tree source)
284{
285  mpfr_from_real (f, TREE_REAL_CST_PTR (source), GFC_RND_MODE);
286}
287
288/* Translate any literal constant to a tree.  Constants never have
289   pre or post chains.  Character literal constants are special
290   special because they have a value and a length, so they cannot be
291   returned as a single tree.  It is up to the caller to set the
292   length somewhere if necessary.
293
294   Returns the translated constant, or aborts if it gets a type it
295   can't handle.  */
296
297tree
298gfc_conv_constant_to_tree (gfc_expr * expr)
299{
300  tree res;
301
302  gcc_assert (expr->expr_type == EXPR_CONSTANT);
303
304  /* If it is has a prescribed memory representation, we build a string
305     constant and VIEW_CONVERT to its type.  */
306
307  switch (expr->ts.type)
308    {
309    case BT_INTEGER:
310      if (expr->representation.string)
311	return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
312			 gfc_get_int_type (expr->ts.kind),
313			 gfc_build_string_const (expr->representation.length,
314						 expr->representation.string));
315      else
316	return gfc_conv_mpz_to_tree (expr->value.integer, expr->ts.kind);
317
318    case BT_REAL:
319      if (expr->representation.string)
320	return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
321			 gfc_get_real_type (expr->ts.kind),
322			 gfc_build_string_const (expr->representation.length,
323						 expr->representation.string));
324      else
325	return gfc_conv_mpfr_to_tree (expr->value.real, expr->ts.kind, expr->is_snan);
326
327    case BT_LOGICAL:
328      if (expr->representation.string)
329	{
330	  tree tmp = fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
331			gfc_get_int_type (expr->ts.kind),
332			gfc_build_string_const (expr->representation.length,
333						expr->representation.string));
334	  if (!integer_zerop (tmp) && !integer_onep (tmp))
335	    gfc_warning (flag_dec_char_conversions ? OPT_Wsurprising : 0,
336			 "Assigning value other than 0 or 1 to LOGICAL has "
337			 "undefined result at %L", &expr->where);
338	  return fold_convert (gfc_get_logical_type (expr->ts.kind), tmp);
339	}
340      else
341	return build_int_cst (gfc_get_logical_type (expr->ts.kind),
342			      expr->value.logical);
343
344    case BT_COMPLEX:
345      if (expr->representation.string)
346	return fold_build1_loc (input_location, VIEW_CONVERT_EXPR,
347			 gfc_get_complex_type (expr->ts.kind),
348			 gfc_build_string_const (expr->representation.length,
349						 expr->representation.string));
350      else
351	{
352	  tree real = gfc_conv_mpfr_to_tree (mpc_realref (expr->value.complex),
353					  expr->ts.kind, expr->is_snan);
354	  tree imag = gfc_conv_mpfr_to_tree (mpc_imagref (expr->value.complex),
355					  expr->ts.kind, expr->is_snan);
356
357	  return build_complex (gfc_typenode_for_spec (&expr->ts),
358				real, imag);
359	}
360
361    case BT_CHARACTER:
362      res = gfc_build_wide_string_const (expr->ts.kind,
363					 expr->value.character.length,
364					 expr->value.character.string);
365      return res;
366
367    case BT_HOLLERITH:
368      return gfc_build_string_const (expr->representation.length,
369				     expr->representation.string);
370
371    default:
372      gcc_unreachable ();
373    }
374}
375
376
377/* Like gfc_conv_constant_to_tree, but for a simplified expression.
378   We can handle character literal constants here as well.  */
379
380void
381gfc_conv_constant (gfc_se * se, gfc_expr * expr)
382{
383  gfc_ss *ss;
384
385  /* We may be receiving an expression for C_NULL_PTR or C_NULL_FUNPTR.  If
386     so, the expr_type will not yet be an EXPR_CONSTANT.  We need to make
387     it so here.  */
388  if (expr->ts.type == BT_DERIVED && expr->ts.u.derived
389      && expr->ts.u.derived->attr.is_iso_c)
390    {
391      if (expr->symtree->n.sym->intmod_sym_id == ISOCBINDING_NULL_PTR
392	  || expr->symtree->n.sym->intmod_sym_id == ISOCBINDING_NULL_FUNPTR)
393	{
394	  /* Create a new EXPR_CONSTANT expression for our local uses.  */
395	  expr = gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
396	}
397    }
398
399  if (expr->expr_type != EXPR_CONSTANT)
400    {
401      gfc_expr *e = gfc_get_int_expr (gfc_default_integer_kind, NULL, 0);
402      gfc_error ("non-constant initialization expression at %L", &expr->where);
403      se->expr = gfc_conv_constant_to_tree (e);
404      return;
405    }
406
407  ss = se->ss;
408  if (ss != NULL)
409    {
410      gfc_ss_info *ss_info;
411
412      ss_info = ss->info;
413      gcc_assert (ss != gfc_ss_terminator);
414      gcc_assert (ss_info->type == GFC_SS_SCALAR);
415      gcc_assert (ss_info->expr == expr);
416
417      se->expr = ss_info->data.scalar.value;
418      se->string_length = ss_info->string_length;
419      gfc_advance_se_ss_chain (se);
420      return;
421    }
422
423  /* Translate the constant and put it in the simplifier structure.  */
424  se->expr = gfc_conv_constant_to_tree (expr);
425
426  /* If this is a CHARACTER string, set its length in the simplifier
427     structure, too.  */
428  if (expr->ts.type == BT_CHARACTER)
429    se->string_length = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (se->expr)));
430}
431