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471086d6 | 1 | /* Language-level data type conversion for GNU C++. |
50a72189 | 2 | Copyright (C) 1987, 88, 92, 93, 94, 95, 1996 Free Software Foundation, Inc. |
471086d6 | 3 | Hacked by Michael Tiemann (tiemann@cygnus.com) |
4 | ||
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
c58d4270 | 19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
20 | Boston, MA 02111-1307, USA. */ | |
471086d6 | 21 | |
22 | ||
23 | /* This file contains the functions for converting C expressions | |
24 | to different data types. The only entry point is `convert'. | |
25 | Every language front end must have a `convert' function | |
26 | but what kind of conversions it does will depend on the language. */ | |
27 | ||
28 | #include "config.h" | |
b3ef7553 | 29 | #include "system.h" |
471086d6 | 30 | #include "tree.h" |
31 | #include "flags.h" | |
32 | #include "cp-tree.h" | |
471086d6 | 33 | #include "convert.h" |
34 | ||
860740a7 | 35 | extern tree static_aggregates; |
96624a9e | 36 | |
71ccdfff | 37 | static tree cp_convert_to_pointer PROTO((tree, tree)); |
38 | static tree convert_to_pointer_force PROTO((tree, tree)); | |
39 | static tree build_up_reference PROTO((tree, tree, int, int)); | |
71ccdfff | 40 | |
471086d6 | 41 | /* Change of width--truncation and extension of integers or reals-- |
42 | is represented with NOP_EXPR. Proper functioning of many things | |
43 | assumes that no other conversions can be NOP_EXPRs. | |
44 | ||
45 | Conversion between integer and pointer is represented with CONVERT_EXPR. | |
46 | Converting integer to real uses FLOAT_EXPR | |
47 | and real to integer uses FIX_TRUNC_EXPR. | |
48 | ||
49 | Here is a list of all the functions that assume that widening and | |
50 | narrowing is always done with a NOP_EXPR: | |
51 | In convert.c, convert_to_integer. | |
52 | In c-typeck.c, build_binary_op_nodefault (boolean ops), | |
53 | and truthvalue_conversion. | |
54 | In expr.c: expand_expr, for operands of a MULT_EXPR. | |
55 | In fold-const.c: fold. | |
56 | In tree.c: get_narrower and get_unwidened. | |
57 | ||
58 | C++: in multiple-inheritance, converting between pointers may involve | |
59 | adjusting them by a delta stored within the class definition. */ | |
60 | \f | |
61 | /* Subroutines of `convert'. */ | |
62 | ||
471086d6 | 63 | /* if converting pointer to pointer |
64 | if dealing with classes, check for derived->base or vice versa | |
65 | else if dealing with method pointers, delegate | |
66 | else convert blindly | |
67 | else if converting class, pass off to build_type_conversion | |
68 | else try C-style pointer conversion */ | |
96624a9e | 69 | |
471086d6 | 70 | static tree |
71 | cp_convert_to_pointer (type, expr) | |
72 | tree type, expr; | |
73 | { | |
74 | register tree intype = TREE_TYPE (expr); | |
74002e1d | 75 | register enum tree_code form; |
f82eeb87 | 76 | tree rval; |
74002e1d | 77 | |
96624a9e | 78 | if (IS_AGGR_TYPE (intype)) |
79 | { | |
96624a9e | 80 | intype = complete_type (intype); |
81 | if (TYPE_SIZE (intype) == NULL_TREE) | |
82 | { | |
83 | cp_error ("can't convert from incomplete type `%T' to `%T'", | |
84 | intype, type); | |
85 | return error_mark_node; | |
86 | } | |
87 | ||
88 | rval = build_type_conversion (CONVERT_EXPR, type, expr, 1); | |
89 | if (rval) | |
90 | { | |
91 | if (rval == error_mark_node) | |
92 | cp_error ("conversion of `%E' from `%T' to `%T' is ambiguous", | |
93 | expr, intype, type); | |
94 | return rval; | |
95 | } | |
96 | } | |
97 | ||
74002e1d | 98 | if (TYPE_PTRMEMFUNC_P (type)) |
99 | type = TYPE_PTRMEMFUNC_FN_TYPE (type); | |
74002e1d | 100 | |
860740a7 | 101 | /* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */ |
38281c46 | 102 | if (TREE_CODE (type) == POINTER_TYPE |
103 | && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE | |
860740a7 | 104 | || TYPE_MAIN_VARIANT (TREE_TYPE (type)) == void_type_node)) |
38281c46 | 105 | { |
106 | /* Allow an implicit this pointer for pointer to member | |
107 | functions. */ | |
860740a7 | 108 | if (TYPE_PTRMEMFUNC_P (intype)) |
38281c46 | 109 | { |
110 | tree decl, basebinfo; | |
860740a7 | 111 | tree fntype = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (intype)); |
38281c46 | 112 | tree t = TYPE_METHOD_BASETYPE (fntype); |
113 | ||
114 | if (current_class_type == 0 | |
115 | || get_base_distance (t, current_class_type, 0, &basebinfo) | |
116 | == -1) | |
117 | { | |
118 | decl = build1 (NOP_EXPR, t, error_mark_node); | |
119 | } | |
120 | else if (current_class_ptr == 0) | |
121 | decl = build1 (NOP_EXPR, t, error_mark_node); | |
122 | else | |
123 | decl = current_class_ref; | |
124 | ||
125 | expr = build (OFFSET_REF, fntype, decl, expr); | |
126 | } | |
127 | ||
128 | if (TREE_CODE (expr) == OFFSET_REF | |
129 | && TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE) | |
130 | expr = resolve_offset_ref (expr); | |
131 | if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE) | |
132 | expr = build_addr_func (expr); | |
133 | if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE) | |
134 | { | |
135 | if (TREE_CODE (TREE_TYPE (TREE_TYPE (expr))) == METHOD_TYPE) | |
136 | if (pedantic || warn_pmf2ptr) | |
137 | cp_pedwarn ("converting from `%T' to `%T'", TREE_TYPE (expr), | |
138 | type); | |
139 | return build1 (NOP_EXPR, type, expr); | |
140 | } | |
141 | intype = TREE_TYPE (expr); | |
142 | } | |
143 | ||
860740a7 | 144 | if (TYPE_PTRMEMFUNC_P (intype)) |
145 | intype = TYPE_PTRMEMFUNC_FN_TYPE (intype); | |
146 | ||
74002e1d | 147 | form = TREE_CODE (intype); |
148 | ||
1a3f833b | 149 | if (form == POINTER_TYPE || form == REFERENCE_TYPE) |
471086d6 | 150 | { |
151 | intype = TYPE_MAIN_VARIANT (intype); | |
152 | ||
153 | if (TYPE_MAIN_VARIANT (type) != intype | |
154 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE | |
bccffb3a | 155 | && IS_AGGR_TYPE (TREE_TYPE (type)) |
156 | && IS_AGGR_TYPE (TREE_TYPE (intype)) | |
471086d6 | 157 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
158 | { | |
159 | enum tree_code code = PLUS_EXPR; | |
160 | tree binfo = get_binfo (TREE_TYPE (type), TREE_TYPE (intype), 1); | |
161 | if (binfo == error_mark_node) | |
162 | return error_mark_node; | |
163 | if (binfo == NULL_TREE) | |
164 | { | |
165 | binfo = get_binfo (TREE_TYPE (intype), TREE_TYPE (type), 1); | |
166 | if (binfo == error_mark_node) | |
167 | return error_mark_node; | |
168 | code = MINUS_EXPR; | |
169 | } | |
170 | if (binfo) | |
171 | { | |
172 | if (TYPE_USES_VIRTUAL_BASECLASSES (TREE_TYPE (type)) | |
173 | || TYPE_USES_VIRTUAL_BASECLASSES (TREE_TYPE (intype)) | |
174 | || ! BINFO_OFFSET_ZEROP (binfo)) | |
175 | { | |
176 | /* Need to get the path we took. */ | |
177 | tree path; | |
178 | ||
179 | if (code == PLUS_EXPR) | |
985e9ee0 | 180 | get_base_distance (TREE_TYPE (type), TREE_TYPE (intype), |
181 | 0, &path); | |
471086d6 | 182 | else |
985e9ee0 | 183 | get_base_distance (TREE_TYPE (intype), TREE_TYPE (type), |
184 | 0, &path); | |
471086d6 | 185 | return build_vbase_path (code, type, expr, path, 0); |
186 | } | |
187 | } | |
188 | } | |
74002e1d | 189 | if (TREE_CODE (TREE_TYPE (intype)) == METHOD_TYPE |
471086d6 | 190 | && TREE_CODE (type) == POINTER_TYPE |
74002e1d | 191 | && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE) |
985e9ee0 | 192 | return build_ptrmemfunc (type, expr, 1); |
471086d6 | 193 | |
bea7d742 | 194 | if (TREE_CODE (TREE_TYPE (type)) == OFFSET_TYPE |
195 | && TREE_CODE (TREE_TYPE (intype)) == OFFSET_TYPE) | |
196 | { | |
197 | tree b1 = TYPE_OFFSET_BASETYPE (TREE_TYPE (type)); | |
198 | tree b2 = TYPE_OFFSET_BASETYPE (TREE_TYPE (intype)); | |
fc9fc8d8 | 199 | tree binfo = get_binfo (b2, b1, 1); |
200 | enum tree_code code = PLUS_EXPR; | |
201 | ||
bea7d742 | 202 | if (binfo == NULL_TREE) |
fc9fc8d8 | 203 | { |
204 | binfo = get_binfo (b1, b2, 1); | |
205 | code = MINUS_EXPR; | |
206 | } | |
207 | ||
bea7d742 | 208 | if (binfo == error_mark_node) |
209 | return error_mark_node; | |
fc9fc8d8 | 210 | if (binfo && ! TREE_VIA_VIRTUAL (binfo)) |
211 | expr = size_binop (code, expr, BINFO_OFFSET (binfo)); | |
bea7d742 | 212 | } |
213 | ||
ce28ee2e | 214 | if (TREE_CODE (TREE_TYPE (intype)) == METHOD_TYPE |
215 | || (TREE_CODE (type) == POINTER_TYPE | |
216 | && TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE)) | |
217 | { | |
218 | cp_error ("cannot convert `%E' from type `%T' to type `%T'", | |
219 | expr, intype, type); | |
220 | return error_mark_node; | |
221 | } | |
222 | ||
f82eeb87 | 223 | rval = build1 (NOP_EXPR, type, expr); |
224 | TREE_CONSTANT (rval) = TREE_CONSTANT (expr); | |
225 | return rval; | |
471086d6 | 226 | } |
227 | ||
228 | my_friendly_assert (form != OFFSET_TYPE, 186); | |
229 | ||
230 | if (TYPE_LANG_SPECIFIC (intype) | |
231 | && (IS_SIGNATURE_POINTER (intype) || IS_SIGNATURE_REFERENCE (intype))) | |
232 | return convert_to_pointer (type, build_optr_ref (expr)); | |
233 | ||
471086d6 | 234 | if (integer_zerop (expr)) |
235 | { | |
11066dd5 | 236 | if (TREE_CODE (TREE_TYPE (type)) == METHOD_TYPE) |
237 | return build_ptrmemfunc (type, expr, 0); | |
471086d6 | 238 | expr = build_int_2 (0, 0); |
239 | TREE_TYPE (expr) = type; | |
240 | return expr; | |
241 | } | |
242 | ||
bb0726a1 | 243 | if (INTEGRAL_CODE_P (form)) |
471086d6 | 244 | { |
245 | if (type_precision (intype) == POINTER_SIZE) | |
246 | return build1 (CONVERT_EXPR, type, expr); | |
c4a8ac95 | 247 | expr = cp_convert (type_for_size (POINTER_SIZE, 0), expr); |
471086d6 | 248 | /* Modes may be different but sizes should be the same. */ |
249 | if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))) | |
250 | != GET_MODE_SIZE (TYPE_MODE (type))) | |
251 | /* There is supposed to be some integral type | |
252 | that is the same width as a pointer. */ | |
253 | abort (); | |
254 | return convert_to_pointer (type, expr); | |
255 | } | |
256 | ||
257 | cp_error ("cannot convert `%E' from type `%T' to type `%T'", | |
258 | expr, intype, type); | |
259 | return error_mark_node; | |
260 | } | |
261 | ||
262 | /* Like convert, except permit conversions to take place which | |
263 | are not normally allowed due to access restrictions | |
264 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 265 | |
471086d6 | 266 | static tree |
267 | convert_to_pointer_force (type, expr) | |
268 | tree type, expr; | |
269 | { | |
270 | register tree intype = TREE_TYPE (expr); | |
271 | register enum tree_code form = TREE_CODE (intype); | |
272 | ||
273 | if (integer_zerop (expr)) | |
274 | { | |
471086d6 | 275 | expr = build_int_2 (0, 0); |
276 | TREE_TYPE (expr) = type; | |
277 | return expr; | |
278 | } | |
279 | ||
280 | /* Convert signature pointer/reference to `void *' first. */ | |
281 | if (form == RECORD_TYPE | |
282 | && (IS_SIGNATURE_POINTER (intype) || IS_SIGNATURE_REFERENCE (intype))) | |
283 | { | |
284 | expr = build_optr_ref (expr); | |
285 | intype = TREE_TYPE (expr); | |
286 | form = TREE_CODE (intype); | |
287 | } | |
288 | ||
289 | if (form == POINTER_TYPE) | |
290 | { | |
291 | intype = TYPE_MAIN_VARIANT (intype); | |
292 | ||
293 | if (TYPE_MAIN_VARIANT (type) != intype | |
294 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE | |
bccffb3a | 295 | && IS_AGGR_TYPE (TREE_TYPE (type)) |
296 | && IS_AGGR_TYPE (TREE_TYPE (intype)) | |
471086d6 | 297 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
298 | { | |
299 | enum tree_code code = PLUS_EXPR; | |
300 | tree path; | |
301 | int distance = get_base_distance (TREE_TYPE (type), | |
302 | TREE_TYPE (intype), 0, &path); | |
303 | if (distance == -2) | |
304 | { | |
305 | ambig: | |
b0df6589 | 306 | cp_error ("type `%T' is ambiguous baseclass of `%s'", |
307 | TREE_TYPE (type), | |
308 | TYPE_NAME_STRING (TREE_TYPE (intype))); | |
471086d6 | 309 | return error_mark_node; |
310 | } | |
311 | if (distance == -1) | |
312 | { | |
313 | distance = get_base_distance (TREE_TYPE (intype), | |
314 | TREE_TYPE (type), 0, &path); | |
315 | if (distance == -2) | |
316 | goto ambig; | |
317 | if (distance < 0) | |
318 | /* Doesn't need any special help from us. */ | |
319 | return build1 (NOP_EXPR, type, expr); | |
320 | ||
321 | code = MINUS_EXPR; | |
322 | } | |
323 | return build_vbase_path (code, type, expr, path, 0); | |
324 | } | |
471086d6 | 325 | } |
326 | ||
327 | return cp_convert_to_pointer (type, expr); | |
328 | } | |
329 | ||
330 | /* We are passing something to a function which requires a reference. | |
331 | The type we are interested in is in TYPE. The initial | |
332 | value we have to begin with is in ARG. | |
333 | ||
334 | FLAGS controls how we manage access checking. | |
c76251c1 | 335 | DIRECT_BIND in FLAGS controls how any temporaries are generated. */ |
96624a9e | 336 | |
471086d6 | 337 | static tree |
338 | build_up_reference (type, arg, flags, checkconst) | |
339 | tree type, arg; | |
340 | int flags, checkconst; | |
341 | { | |
c76251c1 | 342 | tree rval; |
0543e7a9 | 343 | tree argtype = TREE_TYPE (arg); |
471086d6 | 344 | tree target_type = TREE_TYPE (type); |
471086d6 | 345 | |
346 | my_friendly_assert (TREE_CODE (type) == REFERENCE_TYPE, 187); | |
471086d6 | 347 | |
c76251c1 | 348 | if ((flags & DIRECT_BIND) && ! real_lvalue_p (arg)) |
471086d6 | 349 | { |
c76251c1 | 350 | tree targ = arg; |
38281c46 | 351 | if (toplevel_bindings_p ()) |
c76251c1 | 352 | arg = get_temp_name (argtype, 1); |
471086d6 | 353 | else |
354 | { | |
38281c46 | 355 | arg = pushdecl (build_decl (VAR_DECL, NULL_TREE, argtype)); |
356 | DECL_ARTIFICIAL (arg) = 1; | |
1ad432f2 | 357 | } |
38281c46 | 358 | DECL_INITIAL (arg) = targ; |
359 | cp_finish_decl (arg, targ, NULL_TREE, 0, LOOKUP_ONLYCONVERTING); | |
1ad432f2 | 360 | } |
c76251c1 | 361 | else if (!(flags & DIRECT_BIND) && ! lvalue_p (arg)) |
1ad432f2 | 362 | { |
38281c46 | 363 | tree slot = build_decl (VAR_DECL, NULL_TREE, argtype); |
364 | arg = build (TARGET_EXPR, argtype, slot, arg, NULL_TREE, NULL_TREE); | |
0f76a66d | 365 | TREE_SIDE_EFFECTS (arg) = 1; |
471086d6 | 366 | } |
1ad432f2 | 367 | |
b0df6589 | 368 | /* If we had a way to wrap this up, and say, if we ever needed it's |
369 | address, transform all occurrences of the register, into a memory | |
370 | reference we could win better. */ | |
c76251c1 | 371 | rval = build_unary_op (ADDR_EXPR, arg, 1); |
6686e84d | 372 | if ((flags & LOOKUP_PROTECT) |
373 | && TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type) | |
374 | && IS_AGGR_TYPE (argtype) | |
375 | && IS_AGGR_TYPE (target_type)) | |
376 | { | |
377 | /* We go through get_binfo for the access control. */ | |
378 | tree binfo = get_binfo (target_type, argtype, 1); | |
379 | if (binfo == error_mark_node) | |
380 | return error_mark_node; | |
381 | if (binfo == NULL_TREE) | |
382 | return error_not_base_type (target_type, argtype); | |
383 | rval = convert_pointer_to_real (binfo, rval); | |
384 | } | |
c76251c1 | 385 | else |
386 | rval | |
387 | = convert_to_pointer_force (build_pointer_type (target_type), rval); | |
6686e84d | 388 | rval = build1 (NOP_EXPR, type, rval); |
c76251c1 | 389 | TREE_CONSTANT (rval) = TREE_CONSTANT (TREE_OPERAND (rval, 0)); |
471086d6 | 390 | return rval; |
391 | } | |
392 | ||
393 | /* For C++: Only need to do one-level references, but cannot | |
394 | get tripped up on signed/unsigned differences. | |
395 | ||
d81e00a4 | 396 | DECL is either NULL_TREE or the _DECL node for a reference that is being |
397 | initialized. It can be error_mark_node if we don't know the _DECL but | |
398 | we know it's an initialization. */ | |
471086d6 | 399 | |
471086d6 | 400 | tree |
d81e00a4 | 401 | convert_to_reference (reftype, expr, convtype, flags, decl) |
471086d6 | 402 | tree reftype, expr; |
d81e00a4 | 403 | int convtype, flags; |
404 | tree decl; | |
471086d6 | 405 | { |
406 | register tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype)); | |
407 | register tree intype = TREE_TYPE (expr); | |
471086d6 | 408 | tree rval = NULL_TREE; |
1a3f833b | 409 | tree rval_as_conversion = NULL_TREE; |
410 | int i; | |
411 | ||
412 | if (TREE_CODE (intype) == REFERENCE_TYPE) | |
413 | my_friendly_abort (364); | |
471086d6 | 414 | |
471086d6 | 415 | intype = TYPE_MAIN_VARIANT (intype); |
416 | ||
1a3f833b | 417 | i = comp_target_types (type, intype, 0); |
418 | ||
419 | if (i <= 0 && (convtype & CONV_IMPLICIT) && IS_AGGR_TYPE (intype) | |
420 | && ! (flags & LOOKUP_NO_CONVERSION)) | |
421 | { | |
422 | /* Look for a user-defined conversion to lvalue that we can use. */ | |
423 | ||
0a4be248 | 424 | rval_as_conversion |
425 | = build_type_conversion (CONVERT_EXPR, reftype, expr, 1); | |
1a3f833b | 426 | |
427 | if (rval_as_conversion && rval_as_conversion != error_mark_node | |
428 | && real_lvalue_p (rval_as_conversion)) | |
429 | { | |
430 | expr = rval_as_conversion; | |
431 | rval_as_conversion = NULL_TREE; | |
432 | intype = type; | |
433 | i = 1; | |
434 | } | |
435 | } | |
436 | ||
437 | if (((convtype & CONV_STATIC) && i == -1) | |
438 | || ((convtype & CONV_IMPLICIT) && i == 1)) | |
471086d6 | 439 | { |
471086d6 | 440 | if (flags & LOOKUP_COMPLAIN) |
441 | { | |
bc3887cf | 442 | tree ttl = TREE_TYPE (reftype); |
443 | tree ttr; | |
444 | ||
1a3f833b | 445 | { |
446 | int r = TREE_READONLY (expr); | |
447 | int v = TREE_THIS_VOLATILE (expr); | |
448 | ttr = cp_build_type_variant (TREE_TYPE (expr), r, v); | |
449 | } | |
471086d6 | 450 | |
f9670f72 | 451 | if (! real_lvalue_p (expr) && ! TYPE_READONLY (ttl)) |
bc3887cf | 452 | { |
d81e00a4 | 453 | if (decl) |
454 | /* Ensure semantics of [dcl.init.ref] */ | |
f9670f72 | 455 | cp_pedwarn ("initialization of non-const reference `%#T' from rvalue `%T'", |
d81e00a4 | 456 | reftype, intype); |
457 | else | |
f9670f72 | 458 | cp_pedwarn ("conversion to non-const `%T' from rvalue `%T'", |
d81e00a4 | 459 | reftype, intype); |
bc3887cf | 460 | } |
d81e00a4 | 461 | else if (! (convtype & CONV_CONST)) |
471086d6 | 462 | { |
d81e00a4 | 463 | if (! TYPE_READONLY (ttl) && TYPE_READONLY (ttr)) |
464 | cp_pedwarn ("conversion from `%T' to `%T' discards const", | |
ad91f3ed | 465 | ttr, reftype); |
d81e00a4 | 466 | else if (! TYPE_VOLATILE (ttl) && TYPE_VOLATILE (ttr)) |
467 | cp_pedwarn ("conversion from `%T' to `%T' discards volatile", | |
ad91f3ed | 468 | ttr, reftype); |
471086d6 | 469 | } |
0543e7a9 | 470 | } |
471 | ||
d81e00a4 | 472 | return build_up_reference (reftype, expr, flags, |
473 | ! (convtype & CONV_CONST)); | |
471086d6 | 474 | } |
c07b1ad1 | 475 | else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr)) |
0543e7a9 | 476 | { |
477 | /* When casting an lvalue to a reference type, just convert into | |
478 | a pointer to the new type and deference it. This is allowed | |
e581f478 | 479 | by San Diego WP section 5.2.9 paragraph 12, though perhaps it |
0543e7a9 | 480 | should be done directly (jason). (int &)ri ---> *(int*)&ri */ |
e581f478 | 481 | |
3748625f | 482 | /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they |
e581f478 | 483 | meant. */ |
1a3f833b | 484 | if (TREE_CODE (intype) == POINTER_TYPE |
d81e00a4 | 485 | && (comptypes (TREE_TYPE (intype), type, -1))) |
e581f478 | 486 | cp_warning ("casting `%T' to `%T' does not dereference pointer", |
487 | intype, reftype); | |
488 | ||
0543e7a9 | 489 | rval = build_unary_op (ADDR_EXPR, expr, 0); |
490 | if (rval != error_mark_node) | |
985e9ee0 | 491 | rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), |
492 | rval, 0); | |
0543e7a9 | 493 | if (rval != error_mark_node) |
b0722fac | 494 | rval = build1 (NOP_EXPR, reftype, rval); |
0543e7a9 | 495 | } |
0a4be248 | 496 | else |
860740a7 | 497 | { |
498 | rval = convert_for_initialization (NULL_TREE, type, expr, flags, | |
499 | "converting", 0, 0); | |
500 | if (rval == error_mark_node) | |
501 | return error_mark_node; | |
502 | rval = build_up_reference (reftype, rval, flags, 1); | |
503 | ||
504 | if (rval && ! TYPE_READONLY (TREE_TYPE (reftype))) | |
505 | cp_pedwarn ("initializing non-const `%T' with `%T' will use a temporary", | |
506 | reftype, intype); | |
507 | } | |
471086d6 | 508 | |
509 | if (rval) | |
510 | { | |
96624a9e | 511 | /* If we found a way to convert earlier, then use it. */ |
471086d6 | 512 | return rval; |
513 | } | |
514 | ||
1a3f833b | 515 | my_friendly_assert (TREE_CODE (intype) != OFFSET_TYPE, 189); |
471086d6 | 516 | |
b248d3f7 | 517 | if (flags & LOOKUP_COMPLAIN) |
518 | cp_error ("cannot convert type `%T' to type `%T'", intype, reftype); | |
519 | ||
471086d6 | 520 | if (flags & LOOKUP_SPECULATIVELY) |
521 | return NULL_TREE; | |
522 | ||
523 | return error_mark_node; | |
524 | } | |
525 | ||
526 | /* We are using a reference VAL for its value. Bash that reference all the | |
96624a9e | 527 | way down to its lowest form. */ |
528 | ||
471086d6 | 529 | tree |
530 | convert_from_reference (val) | |
531 | tree val; | |
532 | { | |
533 | tree type = TREE_TYPE (val); | |
534 | ||
535 | if (TREE_CODE (type) == OFFSET_TYPE) | |
536 | type = TREE_TYPE (type); | |
8c5c575d | 537 | if (TREE_CODE (type) == REFERENCE_TYPE) |
538 | return build_indirect_ref (val, NULL_PTR); | |
471086d6 | 539 | return val; |
540 | } | |
541 | \f | |
471086d6 | 542 | /* Call this when we know (for any reason) that expr is not, in fact, |
543 | zero. This routine is like convert_pointer_to, but it pays | |
544 | attention to which specific instance of what type we want to | |
545 | convert to. This routine should eventually become | |
546 | convert_to_pointer after all references to convert_to_pointer | |
547 | are removed. */ | |
96624a9e | 548 | |
471086d6 | 549 | tree |
550 | convert_pointer_to_real (binfo, expr) | |
551 | tree binfo, expr; | |
552 | { | |
553 | register tree intype = TREE_TYPE (expr); | |
554 | tree ptr_type; | |
555 | tree type, rval; | |
556 | ||
557 | if (TREE_CODE (binfo) == TREE_VEC) | |
558 | type = BINFO_TYPE (binfo); | |
559 | else if (IS_AGGR_TYPE (binfo)) | |
560 | { | |
561 | type = binfo; | |
562 | } | |
563 | else | |
564 | { | |
565 | type = binfo; | |
566 | binfo = NULL_TREE; | |
567 | } | |
568 | ||
d2a15a12 | 569 | ptr_type = cp_build_type_variant (type, TYPE_READONLY (TREE_TYPE (intype)), |
570 | TYPE_VOLATILE (TREE_TYPE (intype))); | |
571 | ptr_type = build_pointer_type (ptr_type); | |
471086d6 | 572 | if (ptr_type == TYPE_MAIN_VARIANT (intype)) |
573 | return expr; | |
574 | ||
575 | if (intype == error_mark_node) | |
576 | return error_mark_node; | |
577 | ||
578 | my_friendly_assert (!integer_zerop (expr), 191); | |
579 | ||
580 | if (TREE_CODE (type) == RECORD_TYPE | |
581 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE | |
582 | && type != TYPE_MAIN_VARIANT (TREE_TYPE (intype))) | |
583 | { | |
584 | tree path; | |
585 | int distance | |
586 | = get_base_distance (binfo, TYPE_MAIN_VARIANT (TREE_TYPE (intype)), | |
587 | 0, &path); | |
588 | ||
589 | /* This function shouldn't be called with unqualified arguments | |
590 | but if it is, give them an error message that they can read. */ | |
591 | if (distance < 0) | |
592 | { | |
b0722fac | 593 | cp_error ("cannot convert a pointer of type `%T' to a pointer of type `%T'", |
594 | TREE_TYPE (intype), type); | |
471086d6 | 595 | |
596 | if (distance == -2) | |
597 | cp_error ("because `%T' is an ambiguous base class", type); | |
598 | return error_mark_node; | |
599 | } | |
600 | ||
601 | return build_vbase_path (PLUS_EXPR, ptr_type, expr, path, 1); | |
602 | } | |
603 | rval = build1 (NOP_EXPR, ptr_type, | |
604 | TREE_CODE (expr) == NOP_EXPR ? TREE_OPERAND (expr, 0) : expr); | |
605 | TREE_CONSTANT (rval) = TREE_CONSTANT (expr); | |
606 | return rval; | |
607 | } | |
608 | ||
609 | /* Call this when we know (for any reason) that expr is | |
610 | not, in fact, zero. This routine gets a type out of the first | |
611 | argument and uses it to search for the type to convert to. If there | |
612 | is more than one instance of that type in the expr, the conversion is | |
613 | ambiguous. This routine should eventually go away, and all | |
614 | callers should use convert_to_pointer_real. */ | |
96624a9e | 615 | |
471086d6 | 616 | tree |
617 | convert_pointer_to (binfo, expr) | |
618 | tree binfo, expr; | |
619 | { | |
620 | tree type; | |
621 | ||
622 | if (TREE_CODE (binfo) == TREE_VEC) | |
623 | type = BINFO_TYPE (binfo); | |
624 | else if (IS_AGGR_TYPE (binfo)) | |
625 | type = binfo; | |
626 | else | |
627 | type = binfo; | |
628 | return convert_pointer_to_real (type, expr); | |
629 | } | |
471086d6 | 630 | \f |
c4a8ac95 | 631 | /* C++ conversions, preference to static cast conversions. */ |
632 | ||
633 | tree | |
634 | cp_convert (type, expr) | |
635 | tree type, expr; | |
636 | { | |
637 | return ocp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL); | |
638 | } | |
639 | ||
b248d3f7 | 640 | /* Conversion... |
641 | ||
642 | FLAGS indicates how we should behave. */ | |
643 | ||
471086d6 | 644 | tree |
c4a8ac95 | 645 | ocp_convert (type, expr, convtype, flags) |
471086d6 | 646 | tree type, expr; |
d81e00a4 | 647 | int convtype, flags; |
471086d6 | 648 | { |
649 | register tree e = expr; | |
650 | register enum tree_code code = TREE_CODE (type); | |
651 | ||
b465397d | 652 | if (e == error_mark_node |
653 | || TREE_TYPE (e) == error_mark_node) | |
471086d6 | 654 | return error_mark_node; |
d81e00a4 | 655 | |
7745052b | 656 | if (TREE_READONLY_DECL_P (e)) |
657 | e = decl_constant_value (e); | |
658 | ||
2133b374 | 659 | if (IS_AGGR_TYPE (type) && (convtype & CONV_FORCE_TEMP) |
660 | /* Some internal structures (vtable_entry_type, sigtbl_ptr_type) | |
661 | don't go through finish_struct, so they don't have the synthesized | |
662 | constructors. So don't force a temporary. */ | |
663 | && TYPE_HAS_CONSTRUCTOR (type)) | |
1a3f833b | 664 | /* We need a new temporary; don't take this shortcut. */; |
665 | else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (e))) | |
666 | /* Trivial conversion: cv-qualifiers do not matter on rvalues. */ | |
617abf06 | 667 | return fold (build1 (NOP_EXPR, type, e)); |
d81e00a4 | 668 | |
669 | if (code == VOID_TYPE && (convtype & CONV_STATIC)) | |
670 | return build1 (CONVERT_EXPR, type, e); | |
671 | ||
471086d6 | 672 | #if 0 |
673 | /* This is incorrect. A truncation can't be stripped this way. | |
674 | Extensions will be stripped by the use of get_unwidened. */ | |
617abf06 | 675 | if (TREE_CODE (e) == NOP_EXPR) |
c4a8ac95 | 676 | return cp_convert (type, TREE_OPERAND (e, 0)); |
471086d6 | 677 | #endif |
678 | ||
679 | /* Just convert to the type of the member. */ | |
680 | if (code == OFFSET_TYPE) | |
681 | { | |
682 | type = TREE_TYPE (type); | |
683 | code = TREE_CODE (type); | |
684 | } | |
685 | ||
1a3f833b | 686 | #if 0 |
471086d6 | 687 | if (code == REFERENCE_TYPE) |
d81e00a4 | 688 | return fold (convert_to_reference (type, e, convtype, flags, NULL_TREE)); |
471086d6 | 689 | else if (TREE_CODE (TREE_TYPE (e)) == REFERENCE_TYPE) |
690 | e = convert_from_reference (e); | |
1a3f833b | 691 | #endif |
471086d6 | 692 | |
f3ba5c6a | 693 | if (TREE_CODE (e) == OFFSET_REF) |
694 | e = resolve_offset_ref (e); | |
695 | ||
bb0726a1 | 696 | if (INTEGRAL_CODE_P (code)) |
471086d6 | 697 | { |
617abf06 | 698 | tree intype = TREE_TYPE (e); |
02d7f858 | 699 | /* enum = enum, enum = int, enum = float, (enum)pointer are all |
700 | errors. */ | |
471086d6 | 701 | if (flag_int_enum_equivalence == 0 |
702 | && TREE_CODE (type) == ENUMERAL_TYPE | |
02d7f858 | 703 | && ((ARITHMETIC_TYPE_P (intype) && ! (convtype & CONV_STATIC)) |
704 | || (TREE_CODE (intype) == POINTER_TYPE))) | |
471086d6 | 705 | { |
706 | cp_pedwarn ("conversion from `%#T' to `%#T'", intype, type); | |
707 | ||
708 | if (flag_pedantic_errors) | |
709 | return error_mark_node; | |
710 | } | |
f3ba5c6a | 711 | if (IS_AGGR_TYPE (intype)) |
471086d6 | 712 | { |
713 | tree rval; | |
617abf06 | 714 | rval = build_type_conversion (CONVERT_EXPR, type, e, 1); |
6495357a | 715 | if (rval) |
716 | return rval; | |
b248d3f7 | 717 | if (flags & LOOKUP_COMPLAIN) |
718 | cp_error ("`%#T' used where a `%T' was expected", intype, type); | |
719 | if (flags & LOOKUP_SPECULATIVELY) | |
720 | return NULL_TREE; | |
471086d6 | 721 | return error_mark_node; |
722 | } | |
bb0726a1 | 723 | if (code == BOOLEAN_TYPE) |
e4ce2dc4 | 724 | { |
725 | /* Common Ada/Pascal programmer's mistake. We always warn | |
726 | about this since it is so bad. */ | |
727 | if (TREE_CODE (expr) == FUNCTION_DECL) | |
728 | cp_warning ("the address of `%D', will always be `true'", expr); | |
729 | return truthvalue_conversion (e); | |
730 | } | |
471086d6 | 731 | return fold (convert_to_integer (type, e)); |
732 | } | |
74002e1d | 733 | if (code == POINTER_TYPE || code == REFERENCE_TYPE |
734 | || TYPE_PTRMEMFUNC_P (type)) | |
471086d6 | 735 | return fold (cp_convert_to_pointer (type, e)); |
c4a8ac95 | 736 | if (code == REAL_TYPE || code == COMPLEX_TYPE) |
471086d6 | 737 | { |
738 | if (IS_AGGR_TYPE (TREE_TYPE (e))) | |
739 | { | |
740 | tree rval; | |
741 | rval = build_type_conversion (CONVERT_EXPR, type, e, 1); | |
742 | if (rval) | |
743 | return rval; | |
744 | else | |
b248d3f7 | 745 | if (flags & LOOKUP_COMPLAIN) |
746 | cp_error ("`%#T' used where a floating point value was expected", | |
747 | TREE_TYPE (e)); | |
471086d6 | 748 | } |
c4a8ac95 | 749 | if (code == REAL_TYPE) |
750 | return fold (convert_to_real (type, e)); | |
751 | else if (code == COMPLEX_TYPE) | |
752 | return fold (convert_to_complex (type, e)); | |
471086d6 | 753 | } |
754 | ||
755 | /* New C++ semantics: since assignment is now based on | |
756 | memberwise copying, if the rhs type is derived from the | |
757 | lhs type, then we may still do a conversion. */ | |
758 | if (IS_AGGR_TYPE_CODE (code)) | |
759 | { | |
760 | tree dtype = TREE_TYPE (e); | |
c25194fd | 761 | tree ctor = NULL_TREE; |
471086d6 | 762 | |
471086d6 | 763 | dtype = TYPE_MAIN_VARIANT (dtype); |
764 | ||
765 | /* Conversion of object pointers or signature pointers/references | |
766 | to signature pointers/references. */ | |
767 | ||
768 | if (TYPE_LANG_SPECIFIC (type) | |
769 | && (IS_SIGNATURE_POINTER (type) || IS_SIGNATURE_REFERENCE (type))) | |
770 | { | |
771 | tree constructor = build_signature_pointer_constructor (type, expr); | |
772 | tree sig_ty = SIGNATURE_TYPE (type); | |
773 | tree sig_ptr; | |
774 | ||
775 | if (constructor == error_mark_node) | |
776 | return error_mark_node; | |
777 | ||
778 | sig_ptr = get_temp_name (type, 1); | |
779 | DECL_INITIAL (sig_ptr) = constructor; | |
780 | CLEAR_SIGNATURE (sig_ty); | |
6f553a8d | 781 | cp_finish_decl (sig_ptr, constructor, NULL_TREE, 0, 0); |
471086d6 | 782 | SET_SIGNATURE (sig_ty); |
783 | TREE_READONLY (sig_ptr) = 1; | |
784 | ||
785 | return sig_ptr; | |
786 | } | |
787 | ||
788 | /* Conversion between aggregate types. New C++ semantics allow | |
789 | objects of derived type to be cast to objects of base type. | |
790 | Old semantics only allowed this between pointers. | |
791 | ||
792 | There may be some ambiguity between using a constructor | |
793 | vs. using a type conversion operator when both apply. */ | |
794 | ||
0a4be248 | 795 | ctor = e; |
860740a7 | 796 | |
0a4be248 | 797 | if ((flags & LOOKUP_ONLYCONVERTING) |
798 | && ! (IS_AGGR_TYPE (dtype) && DERIVED_FROM_P (type, dtype))) | |
799 | { | |
800 | ctor = build_user_type_conversion (type, ctor, flags); | |
801 | flags |= LOOKUP_NO_CONVERSION; | |
471086d6 | 802 | } |
0a4be248 | 803 | if (ctor) |
804 | ctor = build_method_call (NULL_TREE, ctor_identifier, | |
805 | build_expr_list (NULL_TREE, ctor), | |
806 | TYPE_BINFO (type), flags); | |
807 | if (ctor) | |
808 | return build_cplus_new (type, ctor); | |
471086d6 | 809 | } |
810 | ||
617abf06 | 811 | /* If TYPE or TREE_TYPE (E) is not on the permanent_obstack, |
7745052b | 812 | then it won't be hashed and hence compare as not equal, |
471086d6 | 813 | even when it is. */ |
814 | if (code == ARRAY_TYPE | |
617abf06 | 815 | && TREE_TYPE (TREE_TYPE (e)) == TREE_TYPE (type) |
816 | && index_type_equal (TYPE_DOMAIN (TREE_TYPE (e)), TYPE_DOMAIN (type))) | |
817 | return e; | |
471086d6 | 818 | |
b248d3f7 | 819 | if (flags & LOOKUP_COMPLAIN) |
820 | cp_error ("conversion from `%T' to non-scalar type `%T' requested", | |
821 | TREE_TYPE (expr), type); | |
822 | if (flags & LOOKUP_SPECULATIVELY) | |
823 | return NULL_TREE; | |
471086d6 | 824 | return error_mark_node; |
825 | } | |
826 | ||
d81e00a4 | 827 | /* Create an expression whose value is that of EXPR, |
828 | converted to type TYPE. The TREE_TYPE of the value | |
829 | is always TYPE. This function implements all reasonable | |
830 | conversions; callers should filter out those that are | |
c4a8ac95 | 831 | not permitted by the language being compiled. |
832 | ||
833 | Most of this routine is from build_reinterpret_cast. | |
834 | ||
835 | The backend cannot call cp_convert (what was convert) because | |
836 | conversions to/from basetypes may involve memory references | |
837 | (vbases) and adding or subtracting small values (multiple | |
838 | inheritance), but it calls convert from the constant folding code | |
839 | on subtrees of already build trees after it has ripped them apart. | |
840 | ||
841 | Also, if we ever support range variables, we'll probably also have to | |
842 | do a little bit more work. */ | |
d81e00a4 | 843 | |
844 | tree | |
845 | convert (type, expr) | |
846 | tree type, expr; | |
847 | { | |
c4a8ac95 | 848 | tree intype; |
849 | ||
850 | if (type == error_mark_node || expr == error_mark_node) | |
851 | return error_mark_node; | |
852 | ||
c4a8ac95 | 853 | intype = TREE_TYPE (expr); |
854 | ||
6686e84d | 855 | if (POINTER_TYPE_P (type) && POINTER_TYPE_P (intype)) |
c4a8ac95 | 856 | { |
857 | if (TREE_READONLY_DECL_P (expr)) | |
858 | expr = decl_constant_value (expr); | |
859 | return fold (build1 (NOP_EXPR, type, expr)); | |
860 | } | |
861 | ||
862 | return ocp_convert (type, expr, CONV_OLD_CONVERT, | |
863 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION); | |
d81e00a4 | 864 | } |
865 | ||
c4a8ac95 | 866 | /* Like cp_convert, except permit conversions to take place which |
471086d6 | 867 | are not normally allowed due to access restrictions |
868 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 869 | |
471086d6 | 870 | tree |
a74e8896 | 871 | convert_force (type, expr, convtype) |
471086d6 | 872 | tree type; |
873 | tree expr; | |
a74e8896 | 874 | int convtype; |
471086d6 | 875 | { |
876 | register tree e = expr; | |
877 | register enum tree_code code = TREE_CODE (type); | |
878 | ||
879 | if (code == REFERENCE_TYPE) | |
d81e00a4 | 880 | return fold (convert_to_reference (type, e, CONV_C_CAST, LOOKUP_COMPLAIN, |
881 | NULL_TREE)); | |
471086d6 | 882 | else if (TREE_CODE (TREE_TYPE (e)) == REFERENCE_TYPE) |
883 | e = convert_from_reference (e); | |
884 | ||
885 | if (code == POINTER_TYPE) | |
886 | return fold (convert_to_pointer_force (type, e)); | |
887 | ||
ac9386a0 | 888 | /* From typeck.c convert_for_assignment */ |
471086d6 | 889 | if (((TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE && TREE_CODE (e) == ADDR_EXPR |
890 | && TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE | |
891 | && TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE) | |
ac9386a0 | 892 | || integer_zerop (e) |
893 | || TYPE_PTRMEMFUNC_P (TREE_TYPE (e))) | |
471086d6 | 894 | && TYPE_PTRMEMFUNC_P (type)) |
895 | { | |
96624a9e | 896 | /* compatible pointer to member functions. */ |
ac9386a0 | 897 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1); |
471086d6 | 898 | } |
a74e8896 | 899 | |
c4a8ac95 | 900 | return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL); |
471086d6 | 901 | } |
902 | ||
471086d6 | 903 | /* Convert an aggregate EXPR to type XTYPE. If a conversion |
904 | exists, return the attempted conversion. This may | |
905 | return ERROR_MARK_NODE if the conversion is not | |
906 | allowed (references private members, etc). | |
907 | If no conversion exists, NULL_TREE is returned. | |
908 | ||
909 | If (FOR_SURE & 1) is non-zero, then we allow this type conversion | |
910 | to take place immediately. Otherwise, we build a SAVE_EXPR | |
ce28ee2e | 911 | which can be evaluated if the results are ever needed. |
912 | ||
913 | Changes to this functions should be mirrored in user_harshness. | |
914 | ||
915 | FIXME: Ambiguity checking is wrong. Should choose one by the implicit | |
916 | object parameter, or by the second standard conversion sequence if | |
917 | that doesn't do it. This will probably wait for an overloading rewrite. | |
918 | (jason 8/9/95) */ | |
471086d6 | 919 | |
471086d6 | 920 | tree |
921 | build_type_conversion (code, xtype, expr, for_sure) | |
922 | enum tree_code code; | |
923 | tree xtype, expr; | |
924 | int for_sure; | |
925 | { | |
926 | /* C++: check to see if we can convert this aggregate type | |
bcf789d7 | 927 | into the required type. */ |
0a4be248 | 928 | return build_user_type_conversion |
929 | (xtype, expr, for_sure ? LOOKUP_NORMAL : 0); | |
471086d6 | 930 | } |
931 | ||
1e66592c | 932 | /* Convert the given EXPR to one of a group of types suitable for use in an |
933 | expression. DESIRES is a combination of various WANT_* flags (q.v.) | |
934 | which indicates which types are suitable. If COMPLAIN is 1, complain | |
935 | about ambiguity; otherwise, the caller will deal with it. */ | |
471086d6 | 936 | |
1e66592c | 937 | tree |
938 | build_expr_type_conversion (desires, expr, complain) | |
939 | int desires; | |
940 | tree expr; | |
941 | int complain; | |
471086d6 | 942 | { |
1e66592c | 943 | tree basetype = TREE_TYPE (expr); |
471086d6 | 944 | |
1e66592c | 945 | if (TREE_CODE (basetype) == OFFSET_TYPE) |
ce28ee2e | 946 | expr = resolve_offset_ref (expr); |
947 | expr = convert_from_reference (expr); | |
948 | basetype = TREE_TYPE (expr); | |
471086d6 | 949 | |
985e9ee0 | 950 | switch (TREE_CODE (basetype)) |
471086d6 | 951 | { |
985e9ee0 | 952 | case INTEGER_TYPE: |
953 | if ((desires & WANT_NULL) && TREE_CODE (expr) == INTEGER_CST | |
954 | && integer_zerop (expr)) | |
955 | return expr; | |
956 | /* else fall through... */ | |
957 | ||
958 | case BOOLEAN_TYPE: | |
959 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
960 | case ENUMERAL_TYPE: | |
961 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
962 | case REAL_TYPE: | |
963 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
964 | case POINTER_TYPE: | |
965 | return (desires & WANT_POINTER) ? expr : NULL_TREE; | |
966 | ||
967 | case FUNCTION_TYPE: | |
968 | case ARRAY_TYPE: | |
969 | return ((desires & WANT_POINTER) ? default_conversion (expr) | |
970 | : NULL_TREE); | |
1e66592c | 971 | |
972 | default: | |
985e9ee0 | 973 | break; |
471086d6 | 974 | } |
1e66592c | 975 | |
985e9ee0 | 976 | return NULL_TREE; |
471086d6 | 977 | } |
bc3887cf | 978 | |
96624a9e | 979 | /* Implements integral promotion (4.1) and float->double promotion. */ |
980 | ||
bc3887cf | 981 | tree |
982 | type_promotes_to (type) | |
983 | tree type; | |
984 | { | |
ce28ee2e | 985 | int constp, volatilep; |
986 | ||
987 | if (type == error_mark_node) | |
988 | return error_mark_node; | |
989 | ||
990 | constp = TYPE_READONLY (type); | |
991 | volatilep = TYPE_VOLATILE (type); | |
bc3887cf | 992 | type = TYPE_MAIN_VARIANT (type); |
bb0726a1 | 993 | |
994 | /* bool always promotes to int (not unsigned), even if it's the same | |
995 | size. */ | |
028ea8b4 | 996 | if (type == boolean_type_node) |
bb0726a1 | 997 | type = integer_type_node; |
998 | ||
999 | /* Normally convert enums to int, but convert wide enums to something | |
1000 | wider. */ | |
1001 | else if (TREE_CODE (type) == ENUMERAL_TYPE | |
1002 | || type == wchar_type_node) | |
6c9497b1 | 1003 | { |
1004 | int precision = MAX (TYPE_PRECISION (type), | |
1005 | TYPE_PRECISION (integer_type_node)); | |
1006 | tree totype = type_for_size (precision, 0); | |
1007 | if (TREE_UNSIGNED (type) | |
1008 | && ! int_fits_type_p (TYPE_MAX_VALUE (type), totype)) | |
1009 | type = type_for_size (precision, 1); | |
1010 | else | |
1011 | type = totype; | |
1012 | } | |
bc3887cf | 1013 | else if (C_PROMOTING_INTEGER_TYPE_P (type)) |
1014 | { | |
d0acef9e | 1015 | /* Retain unsignedness if really not getting bigger. */ |
bc3887cf | 1016 | if (TREE_UNSIGNED (type) |
d0acef9e | 1017 | && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) |
bc3887cf | 1018 | type = unsigned_type_node; |
1019 | else | |
1020 | type = integer_type_node; | |
1021 | } | |
1022 | else if (type == float_type_node) | |
1023 | type = double_type_node; | |
1024 | ||
c38086bd | 1025 | return cp_build_type_variant (type, constp, volatilep); |
bc3887cf | 1026 | } |
668ae905 | 1027 | |
1028 | ||
1029 | /* The routines below this point are carefully written to conform to | |
1030 | the standard. They use the same terminology, and follow the rules | |
1031 | closely. Although they are used only in pt.c at the moment, they | |
1032 | should presumably be used everywhere in the future. */ | |
1033 | ||
1146f179 | 1034 | /* Attempt to perform qualification conversions on EXPR to convert it |
1035 | to TYPE. Return the resulting expression, or error_mark_node if | |
1036 | the conversion was impossible. */ | |
1037 | ||
668ae905 | 1038 | tree |
1039 | perform_qualification_conversions (type, expr) | |
1040 | tree type; | |
1041 | tree expr; | |
1042 | { | |
77a851e4 | 1043 | if (comp_target_types (type, TREE_TYPE (expr), 0) == 1) |
1146f179 | 1044 | return build1 (NOP_EXPR, type, expr); |
1045 | else | |
1046 | return error_mark_node; | |
668ae905 | 1047 | } |