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471086d6 | 1 | /* Language-level data type conversion for GNU C++. |
107c7f39 | 2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
af86cc06 | 3 | 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. |
471086d6 | 4 | Hacked by Michael Tiemann (tiemann@cygnus.com) |
5 | ||
6f0d25a6 | 6 | This file is part of GCC. |
471086d6 | 7 | |
6f0d25a6 | 8 | GCC is free software; you can redistribute it and/or modify |
471086d6 | 9 | it under the terms of the GNU General Public License as published by |
10 | the Free Software Foundation; either version 2, or (at your option) | |
11 | any later version. | |
12 | ||
6f0d25a6 | 13 | GCC is distributed in the hope that it will be useful, |
471086d6 | 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
6f0d25a6 | 19 | along with GCC; see the file COPYING. If not, write to |
c58d4270 | 20 | the Free Software Foundation, 59 Temple Place - Suite 330, |
21 | Boston, MA 02111-1307, USA. */ | |
471086d6 | 22 | |
23 | ||
af86cc06 | 24 | /* This file contains the functions for converting C++ expressions |
471086d6 | 25 | to different data types. The only entry point is `convert'. |
26 | Every language front end must have a `convert' function | |
27 | but what kind of conversions it does will depend on the language. */ | |
28 | ||
29 | #include "config.h" | |
b3ef7553 | 30 | #include "system.h" |
805e22b2 | 31 | #include "coretypes.h" |
32 | #include "tm.h" | |
471086d6 | 33 | #include "tree.h" |
34 | #include "flags.h" | |
35 | #include "cp-tree.h" | |
471086d6 | 36 | #include "convert.h" |
f0eaeecd | 37 | #include "toplev.h" |
2e8226f7 | 38 | #include "decl.h" |
96624a9e | 39 | |
35771a9a | 40 | static tree cp_convert_to_pointer (tree, tree, bool); |
41 | static tree convert_to_pointer_force (tree, tree); | |
42 | static tree build_up_reference (tree, tree, int, tree); | |
43 | static void warn_ref_binding (tree, tree, tree); | |
71ccdfff | 44 | |
471086d6 | 45 | /* Change of width--truncation and extension of integers or reals-- |
46 | is represented with NOP_EXPR. Proper functioning of many things | |
47 | assumes that no other conversions can be NOP_EXPRs. | |
48 | ||
49 | Conversion between integer and pointer is represented with CONVERT_EXPR. | |
50 | Converting integer to real uses FLOAT_EXPR | |
51 | and real to integer uses FIX_TRUNC_EXPR. | |
52 | ||
53 | Here is a list of all the functions that assume that widening and | |
54 | narrowing is always done with a NOP_EXPR: | |
55 | In convert.c, convert_to_integer. | |
56 | In c-typeck.c, build_binary_op_nodefault (boolean ops), | |
aff9e656 | 57 | and c_common_truthvalue_conversion. |
471086d6 | 58 | In expr.c: expand_expr, for operands of a MULT_EXPR. |
59 | In fold-const.c: fold. | |
60 | In tree.c: get_narrower and get_unwidened. | |
61 | ||
62 | C++: in multiple-inheritance, converting between pointers may involve | |
63 | adjusting them by a delta stored within the class definition. */ | |
64 | \f | |
65 | /* Subroutines of `convert'. */ | |
66 | ||
471086d6 | 67 | /* if converting pointer to pointer |
68 | if dealing with classes, check for derived->base or vice versa | |
69 | else if dealing with method pointers, delegate | |
70 | else convert blindly | |
71 | else if converting class, pass off to build_type_conversion | |
045ed8f8 | 72 | else try C-style pointer conversion. If FORCE is true then allow |
73 | conversions via virtual bases (these are permitted by reinterpret_cast, | |
74 | but not static_cast). */ | |
96624a9e | 75 | |
471086d6 | 76 | static tree |
35771a9a | 77 | cp_convert_to_pointer (tree type, tree expr, bool force) |
471086d6 | 78 | { |
79 | register tree intype = TREE_TYPE (expr); | |
74002e1d | 80 | register enum tree_code form; |
f82eeb87 | 81 | tree rval; |
74002e1d | 82 | |
96624a9e | 83 | if (IS_AGGR_TYPE (intype)) |
84 | { | |
96624a9e | 85 | intype = complete_type (intype); |
4b72716d | 86 | if (!COMPLETE_TYPE_P (intype)) |
96624a9e | 87 | { |
cf103c6c | 88 | error ("can't convert from incomplete type `%T' to `%T'", |
96624a9e | 89 | intype, type); |
90 | return error_mark_node; | |
91 | } | |
92 | ||
8999978b | 93 | rval = build_type_conversion (type, expr); |
96624a9e | 94 | if (rval) |
95 | { | |
96 | if (rval == error_mark_node) | |
cf103c6c | 97 | error ("conversion of `%E' from `%T' to `%T' is ambiguous", |
96624a9e | 98 | expr, intype, type); |
99 | return rval; | |
100 | } | |
101 | } | |
102 | ||
860740a7 | 103 | /* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */ |
38281c46 | 104 | if (TREE_CODE (type) == POINTER_TYPE |
105 | && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE | |
e3cfe3ce | 106 | || VOID_TYPE_P (TREE_TYPE (type)))) |
38281c46 | 107 | { |
108 | /* Allow an implicit this pointer for pointer to member | |
109 | functions. */ | |
860740a7 | 110 | if (TYPE_PTRMEMFUNC_P (intype)) |
38281c46 | 111 | { |
a63bc44c | 112 | if (pedantic || warn_pmf2ptr) |
113 | pedwarn ("converting from `%T' to `%T'", intype, type); | |
114 | if (TREE_CODE (expr) == PTRMEM_CST) | |
115 | expr = build_address (PTRMEM_CST_MEMBER (expr)); | |
116 | else | |
117 | { | |
118 | tree decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), | |
119 | 0); | |
120 | decl = build_address (decl); | |
121 | expr = get_member_function_from_ptrfunc (&decl, expr); | |
122 | } | |
38281c46 | 123 | } |
a63bc44c | 124 | else if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE) |
38281c46 | 125 | { |
a63bc44c | 126 | if (pedantic || warn_pmf2ptr) |
127 | pedwarn ("converting from `%T' to `%T'", intype, type); | |
128 | expr = build_addr_func (expr); | |
38281c46 | 129 | } |
a63bc44c | 130 | if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE) |
131 | return build_nop (type, expr); | |
38281c46 | 132 | intype = TREE_TYPE (expr); |
133 | } | |
134 | ||
311e42bc | 135 | if (expr == error_mark_node) |
136 | return error_mark_node; | |
137 | ||
74002e1d | 138 | form = TREE_CODE (intype); |
139 | ||
2b77484d | 140 | if (POINTER_TYPE_P (intype)) |
471086d6 | 141 | { |
142 | intype = TYPE_MAIN_VARIANT (intype); | |
143 | ||
144 | if (TYPE_MAIN_VARIANT (type) != intype | |
2b77484d | 145 | && TREE_CODE (type) == POINTER_TYPE |
471086d6 | 146 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE |
bccffb3a | 147 | && IS_AGGR_TYPE (TREE_TYPE (type)) |
148 | && IS_AGGR_TYPE (TREE_TYPE (intype)) | |
4a2680fc | 149 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
471086d6 | 150 | { |
151 | enum tree_code code = PLUS_EXPR; | |
4a2680fc | 152 | tree binfo; |
8999978b | 153 | tree intype_class; |
154 | tree type_class; | |
155 | bool same_p; | |
4a2680fc | 156 | |
8999978b | 157 | intype_class = TREE_TYPE (intype); |
158 | type_class = TREE_TYPE (type); | |
159 | ||
160 | same_p = same_type_p (TYPE_MAIN_VARIANT (intype_class), | |
161 | TYPE_MAIN_VARIANT (type_class)); | |
162 | binfo = NULL_TREE; | |
c0af329c | 163 | /* Try derived to base conversion. */ |
8999978b | 164 | if (!same_p) |
165 | binfo = lookup_base (intype_class, type_class, ba_check, NULL); | |
166 | if (!same_p && !binfo) | |
471086d6 | 167 | { |
c0af329c | 168 | /* Try base to derived conversion. */ |
8999978b | 169 | binfo = lookup_base (type_class, intype_class, ba_check, NULL); |
471086d6 | 170 | code = MINUS_EXPR; |
171 | } | |
4a2680fc | 172 | if (binfo == error_mark_node) |
173 | return error_mark_node; | |
8999978b | 174 | if (binfo || same_p) |
471086d6 | 175 | { |
8999978b | 176 | if (binfo) |
177 | expr = build_base_path (code, expr, binfo, 0); | |
c0af329c | 178 | /* Add any qualifier conversions. */ |
8999978b | 179 | return build_nop (type, expr); |
471086d6 | 180 | } |
181 | } | |
471086d6 | 182 | |
1bc16cab | 183 | if (TYPE_PTRMEMFUNC_P (type)) |
bea7d742 | 184 | { |
1bc16cab | 185 | error ("cannot convert `%E' from type `%T' to type `%T'", |
186 | expr, intype, type); | |
187 | return error_mark_node; | |
188 | } | |
a17aefa2 | 189 | |
1bc16cab | 190 | return build_nop (type, expr); |
191 | } | |
192 | else if (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)) | |
193 | { | |
194 | tree b1; | |
195 | tree b2; | |
196 | tree binfo; | |
197 | enum tree_code code = PLUS_EXPR; | |
198 | base_kind bk; | |
199 | ||
200 | b1 = TYPE_PTRMEM_CLASS_TYPE (type); | |
201 | b2 = TYPE_PTRMEM_CLASS_TYPE (intype); | |
202 | binfo = lookup_base (b1, b2, ba_check, &bk); | |
203 | if (!binfo) | |
204 | { | |
205 | binfo = lookup_base (b2, b1, ba_check, &bk); | |
206 | code = MINUS_EXPR; | |
207 | } | |
208 | if (binfo == error_mark_node) | |
209 | return error_mark_node; | |
a17aefa2 | 210 | |
1bc16cab | 211 | if (bk == bk_via_virtual) |
212 | { | |
213 | if (force) | |
214 | warning ("pointer to member cast from `%T' to `%T' is via virtual base", | |
215 | intype, type); | |
216 | else | |
7045d67a | 217 | { |
1bc16cab | 218 | error ("pointer to member cast from `%T' to `%T' is via virtual base", |
219 | intype, type); | |
220 | return error_mark_node; | |
7045d67a | 221 | } |
1bc16cab | 222 | /* This is a reinterpret cast, whose result is unspecified. |
223 | We choose to do nothing. */ | |
224 | return build1 (NOP_EXPR, type, expr); | |
ce28ee2e | 225 | } |
226 | ||
1bc16cab | 227 | if (TREE_CODE (expr) == PTRMEM_CST) |
228 | expr = cplus_expand_constant (expr); | |
229 | ||
230 | if (binfo && !integer_zerop (BINFO_OFFSET (binfo))) | |
231 | expr = size_binop (code, | |
232 | build_nop (sizetype, expr), | |
233 | BINFO_OFFSET (binfo)); | |
8999978b | 234 | return build_nop (type, expr); |
471086d6 | 235 | } |
2b77484d | 236 | else if (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)) |
7045d67a | 237 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0); |
2b77484d | 238 | else if (TYPE_PTRMEMFUNC_P (intype)) |
239 | { | |
a63bc44c | 240 | if (!warn_pmf2ptr) |
241 | { | |
242 | if (TREE_CODE (expr) == PTRMEM_CST) | |
243 | return cp_convert_to_pointer (type, | |
244 | PTRMEM_CST_MEMBER (expr), | |
245 | force); | |
246 | else if (TREE_CODE (expr) == OFFSET_REF) | |
247 | { | |
248 | tree object = TREE_OPERAND (expr, 0); | |
249 | return get_member_function_from_ptrfunc (&object, | |
250 | TREE_OPERAND (expr, 1)); | |
251 | } | |
252 | } | |
cf103c6c | 253 | error ("cannot convert `%E' from type `%T' to type `%T'", |
2b77484d | 254 | expr, intype, type); |
255 | return error_mark_node; | |
256 | } | |
471086d6 | 257 | |
471086d6 | 258 | if (integer_zerop (expr)) |
259 | { | |
2b77484d | 260 | if (TYPE_PTRMEMFUNC_P (type)) |
f05d5d03 | 261 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0); |
ad63a0fc | 262 | |
606b494c | 263 | if (TYPE_PTRMEM_P (type)) |
5ad590ad | 264 | /* A NULL pointer-to-member is represented by -1, not by |
265 | zero. */ | |
ad63a0fc | 266 | expr = build_int_2 (-1, -1); |
267 | else | |
268 | expr = build_int_2 (0, 0); | |
471086d6 | 269 | TREE_TYPE (expr) = type; |
8f5d16f2 | 270 | /* Fix up the representation of -1 if appropriate. */ |
271 | force_fit_type (expr, 0); | |
471086d6 | 272 | return expr; |
273 | } | |
1bc16cab | 274 | else if (TYPE_PTR_TO_MEMBER_P (type) && INTEGRAL_CODE_P (form)) |
de1f960a | 275 | { |
276 | error ("invalid conversion from '%T' to '%T'", intype, type); | |
277 | return error_mark_node; | |
278 | } | |
471086d6 | 279 | |
bb0726a1 | 280 | if (INTEGRAL_CODE_P (form)) |
471086d6 | 281 | { |
c5aa1e92 | 282 | if (TYPE_PRECISION (intype) == POINTER_SIZE) |
471086d6 | 283 | return build1 (CONVERT_EXPR, type, expr); |
771d21fa | 284 | expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr); |
471086d6 | 285 | /* Modes may be different but sizes should be the same. */ |
286 | if (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))) | |
287 | != GET_MODE_SIZE (TYPE_MODE (type))) | |
288 | /* There is supposed to be some integral type | |
289 | that is the same width as a pointer. */ | |
290 | abort (); | |
291 | return convert_to_pointer (type, expr); | |
292 | } | |
293 | ||
cc4d0855 | 294 | if (type_unknown_p (expr)) |
4b471722 | 295 | return instantiate_type (type, expr, tf_error | tf_warning); |
cc4d0855 | 296 | |
cf103c6c | 297 | error ("cannot convert `%E' from type `%T' to type `%T'", |
471086d6 | 298 | expr, intype, type); |
299 | return error_mark_node; | |
300 | } | |
301 | ||
302 | /* Like convert, except permit conversions to take place which | |
303 | are not normally allowed due to access restrictions | |
304 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 305 | |
471086d6 | 306 | static tree |
35771a9a | 307 | convert_to_pointer_force (tree type, tree expr) |
471086d6 | 308 | { |
309 | register tree intype = TREE_TYPE (expr); | |
310 | register enum tree_code form = TREE_CODE (intype); | |
311 | ||
471086d6 | 312 | if (form == POINTER_TYPE) |
313 | { | |
314 | intype = TYPE_MAIN_VARIANT (intype); | |
315 | ||
316 | if (TYPE_MAIN_VARIANT (type) != intype | |
317 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE | |
bccffb3a | 318 | && IS_AGGR_TYPE (TREE_TYPE (type)) |
319 | && IS_AGGR_TYPE (TREE_TYPE (intype)) | |
471086d6 | 320 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
321 | { | |
322 | enum tree_code code = PLUS_EXPR; | |
4a2680fc | 323 | tree binfo; |
324 | ||
325 | binfo = lookup_base (TREE_TYPE (intype), TREE_TYPE (type), | |
326 | ba_ignore, NULL); | |
327 | if (!binfo) | |
471086d6 | 328 | { |
4a2680fc | 329 | binfo = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), |
330 | ba_ignore, NULL); | |
331 | code = MINUS_EXPR; | |
471086d6 | 332 | } |
4a2680fc | 333 | if (binfo == error_mark_node) |
334 | return error_mark_node; | |
335 | if (binfo) | |
471086d6 | 336 | { |
4a2680fc | 337 | expr = build_base_path (code, expr, binfo, 0); |
de922179 | 338 | if (expr == error_mark_node) |
339 | return error_mark_node; | |
c0af329c | 340 | /* Add any qualifier conversions. */ |
4a2680fc | 341 | if (!same_type_p (TREE_TYPE (TREE_TYPE (expr)), |
342 | TREE_TYPE (type))) | |
8999978b | 343 | expr = build_nop (type, expr); |
4a2680fc | 344 | return expr; |
471086d6 | 345 | } |
471086d6 | 346 | } |
471086d6 | 347 | } |
348 | ||
35771a9a | 349 | return cp_convert_to_pointer (type, expr, true); |
471086d6 | 350 | } |
351 | ||
352 | /* We are passing something to a function which requires a reference. | |
353 | The type we are interested in is in TYPE. The initial | |
354 | value we have to begin with is in ARG. | |
355 | ||
356 | FLAGS controls how we manage access checking. | |
ca106ab1 | 357 | DIRECT_BIND in FLAGS controls how any temporaries are generated. |
358 | If DIRECT_BIND is set, DECL is the reference we're binding to. */ | |
96624a9e | 359 | |
471086d6 | 360 | static tree |
35771a9a | 361 | build_up_reference (tree type, tree arg, int flags, tree decl) |
471086d6 | 362 | { |
c76251c1 | 363 | tree rval; |
0543e7a9 | 364 | tree argtype = TREE_TYPE (arg); |
471086d6 | 365 | tree target_type = TREE_TYPE (type); |
471086d6 | 366 | |
367 | my_friendly_assert (TREE_CODE (type) == REFERENCE_TYPE, 187); | |
471086d6 | 368 | |
c76251c1 | 369 | if ((flags & DIRECT_BIND) && ! real_lvalue_p (arg)) |
471086d6 | 370 | { |
ca106ab1 | 371 | /* Create a new temporary variable. We can't just use a TARGET_EXPR |
372 | here because it needs to live as long as DECL. */ | |
c76251c1 | 373 | tree targ = arg; |
ca106ab1 | 374 | |
7c09476d | 375 | arg = make_temporary_var_for_ref_to_temp (decl, TREE_TYPE (arg)); |
c23ebfdd | 376 | |
377 | /* Process the initializer for the declaration. */ | |
38281c46 | 378 | DECL_INITIAL (arg) = targ; |
ce23987e | 379 | cp_finish_decl (arg, targ, NULL_TREE, |
011310f7 | 380 | LOOKUP_ONLYCONVERTING|DIRECT_BIND); |
1ad432f2 | 381 | } |
c76251c1 | 382 | else if (!(flags & DIRECT_BIND) && ! lvalue_p (arg)) |
1d8e4310 | 383 | return get_target_expr (arg); |
1ad432f2 | 384 | |
ca106ab1 | 385 | /* If we had a way to wrap this up, and say, if we ever needed its |
b0df6589 | 386 | address, transform all occurrences of the register, into a memory |
387 | reference we could win better. */ | |
c76251c1 | 388 | rval = build_unary_op (ADDR_EXPR, arg, 1); |
15e55420 | 389 | if (rval == error_mark_node) |
390 | return error_mark_node; | |
391 | ||
6686e84d | 392 | if ((flags & LOOKUP_PROTECT) |
393 | && TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type) | |
394 | && IS_AGGR_TYPE (argtype) | |
395 | && IS_AGGR_TYPE (target_type)) | |
396 | { | |
7e6960e0 | 397 | /* We go through lookup_base for the access control. */ |
4a2680fc | 398 | tree binfo = lookup_base (argtype, target_type, ba_check, NULL); |
6686e84d | 399 | if (binfo == error_mark_node) |
400 | return error_mark_node; | |
401 | if (binfo == NULL_TREE) | |
402 | return error_not_base_type (target_type, argtype); | |
4a2680fc | 403 | rval = build_base_path (PLUS_EXPR, rval, binfo, 1); |
6686e84d | 404 | } |
c76251c1 | 405 | else |
406 | rval | |
407 | = convert_to_pointer_force (build_pointer_type (target_type), rval); | |
8999978b | 408 | return build_nop (type, rval); |
471086d6 | 409 | } |
410 | ||
519ba62c | 411 | /* Subroutine of convert_to_reference. REFTYPE is the target reference type. |
412 | INTYPE is the original rvalue type and DECL is an optional _DECL node | |
413 | for diagnostics. | |
414 | ||
415 | [dcl.init.ref] says that if an rvalue is used to | |
416 | initialize a reference, then the reference must be to a | |
417 | non-volatile const type. */ | |
418 | ||
419 | static void | |
35771a9a | 420 | warn_ref_binding (tree reftype, tree intype, tree decl) |
519ba62c | 421 | { |
422 | tree ttl = TREE_TYPE (reftype); | |
423 | ||
424 | if (!CP_TYPE_CONST_NON_VOLATILE_P (ttl)) | |
425 | { | |
426 | const char *msg; | |
427 | ||
428 | if (CP_TYPE_VOLATILE_P (ttl) && decl) | |
429 | msg = "initialization of volatile reference type `%#T' from rvalue of type `%T'"; | |
430 | else if (CP_TYPE_VOLATILE_P (ttl)) | |
431 | msg = "conversion to volatile reference type `%#T' from rvalue of type `%T'"; | |
432 | else if (decl) | |
433 | msg = "initialization of non-const reference type `%#T' from rvalue of type `%T'"; | |
434 | else | |
435 | msg = "conversion to non-const reference type `%#T' from rvalue of type `%T'"; | |
436 | ||
cf103c6c | 437 | pedwarn (msg, reftype, intype); |
519ba62c | 438 | } |
439 | } | |
440 | ||
471086d6 | 441 | /* For C++: Only need to do one-level references, but cannot |
442 | get tripped up on signed/unsigned differences. | |
443 | ||
d81e00a4 | 444 | DECL is either NULL_TREE or the _DECL node for a reference that is being |
445 | initialized. It can be error_mark_node if we don't know the _DECL but | |
446 | we know it's an initialization. */ | |
471086d6 | 447 | |
471086d6 | 448 | tree |
35771a9a | 449 | convert_to_reference (tree reftype, tree expr, int convtype, |
450 | int flags, tree decl) | |
471086d6 | 451 | { |
452 | register tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype)); | |
d32df6a6 | 453 | register tree intype; |
471086d6 | 454 | tree rval = NULL_TREE; |
1a3f833b | 455 | tree rval_as_conversion = NULL_TREE; |
1bc16cab | 456 | bool can_convert_intype_to_type; |
1a3f833b | 457 | |
d32df6a6 | 458 | if (TREE_CODE (type) == FUNCTION_TYPE |
459 | && TREE_TYPE (expr) == unknown_type_node) | |
0a3b29ad | 460 | expr = instantiate_type (type, expr, |
461 | (flags & LOOKUP_COMPLAIN) | |
462 | ? tf_error | tf_warning : tf_none); | |
d32df6a6 | 463 | else |
0a3b29ad | 464 | expr = convert_from_reference (expr); |
465 | ||
466 | if (expr == error_mark_node) | |
467 | return error_mark_node; | |
468 | ||
469 | intype = TREE_TYPE (expr); | |
cc4d0855 | 470 | |
8bc57e28 | 471 | my_friendly_assert (TREE_CODE (intype) != REFERENCE_TYPE, 364); |
471086d6 | 472 | |
471086d6 | 473 | intype = TYPE_MAIN_VARIANT (intype); |
474 | ||
1bc16cab | 475 | can_convert_intype_to_type = can_convert (type, intype); |
476 | if (!can_convert_intype_to_type | |
477 | && (convtype & CONV_IMPLICIT) && IS_AGGR_TYPE (intype) | |
1a3f833b | 478 | && ! (flags & LOOKUP_NO_CONVERSION)) |
479 | { | |
480 | /* Look for a user-defined conversion to lvalue that we can use. */ | |
481 | ||
0a4be248 | 482 | rval_as_conversion |
8999978b | 483 | = build_type_conversion (reftype, expr); |
1a3f833b | 484 | |
485 | if (rval_as_conversion && rval_as_conversion != error_mark_node | |
486 | && real_lvalue_p (rval_as_conversion)) | |
487 | { | |
488 | expr = rval_as_conversion; | |
489 | rval_as_conversion = NULL_TREE; | |
490 | intype = type; | |
1bc16cab | 491 | can_convert_intype_to_type = 1; |
1a3f833b | 492 | } |
493 | } | |
494 | ||
1bc16cab | 495 | if (((convtype & CONV_STATIC) && can_convert (intype, type)) |
496 | || ((convtype & CONV_IMPLICIT) && can_convert_intype_to_type)) | |
471086d6 | 497 | { |
471086d6 | 498 | if (flags & LOOKUP_COMPLAIN) |
499 | { | |
bc3887cf | 500 | tree ttl = TREE_TYPE (reftype); |
cb0ba4ec | 501 | tree ttr = lvalue_type (expr); |
471086d6 | 502 | |
519ba62c | 503 | if (! real_lvalue_p (expr)) |
504 | warn_ref_binding (reftype, intype, decl); | |
505 | ||
506 | if (! (convtype & CONV_CONST) | |
3e04bd45 | 507 | && !at_least_as_qualified_p (ttl, ttr)) |
cf103c6c | 508 | pedwarn ("conversion from `%T' to `%T' discards qualifiers", |
caa99b15 | 509 | ttr, reftype); |
0543e7a9 | 510 | } |
511 | ||
ca106ab1 | 512 | return build_up_reference (reftype, expr, flags, decl); |
471086d6 | 513 | } |
c07b1ad1 | 514 | else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr)) |
0543e7a9 | 515 | { |
516 | /* When casting an lvalue to a reference type, just convert into | |
517 | a pointer to the new type and deference it. This is allowed | |
e581f478 | 518 | by San Diego WP section 5.2.9 paragraph 12, though perhaps it |
0543e7a9 | 519 | should be done directly (jason). (int &)ri ---> *(int*)&ri */ |
e581f478 | 520 | |
3748625f | 521 | /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they |
e581f478 | 522 | meant. */ |
1a3f833b | 523 | if (TREE_CODE (intype) == POINTER_TYPE |
00952d10 | 524 | && (comptypes (TREE_TYPE (intype), type, |
525 | COMPARE_BASE | COMPARE_DERIVED))) | |
cf103c6c | 526 | warning ("casting `%T' to `%T' does not dereference pointer", |
00952d10 | 527 | intype, reftype); |
e581f478 | 528 | |
0543e7a9 | 529 | rval = build_unary_op (ADDR_EXPR, expr, 0); |
530 | if (rval != error_mark_node) | |
985e9ee0 | 531 | rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), |
532 | rval, 0); | |
0543e7a9 | 533 | if (rval != error_mark_node) |
b0722fac | 534 | rval = build1 (NOP_EXPR, reftype, rval); |
0543e7a9 | 535 | } |
0a4be248 | 536 | else |
860740a7 | 537 | { |
538 | rval = convert_for_initialization (NULL_TREE, type, expr, flags, | |
539 | "converting", 0, 0); | |
a66fe4cb | 540 | if (rval == NULL_TREE || rval == error_mark_node) |
541 | return rval; | |
519ba62c | 542 | warn_ref_binding (reftype, intype, decl); |
ca106ab1 | 543 | rval = build_up_reference (reftype, rval, flags, decl); |
860740a7 | 544 | } |
471086d6 | 545 | |
546 | if (rval) | |
547 | { | |
96624a9e | 548 | /* If we found a way to convert earlier, then use it. */ |
471086d6 | 549 | return rval; |
550 | } | |
551 | ||
b248d3f7 | 552 | if (flags & LOOKUP_COMPLAIN) |
cf103c6c | 553 | error ("cannot convert type `%T' to type `%T'", intype, reftype); |
b248d3f7 | 554 | |
471086d6 | 555 | if (flags & LOOKUP_SPECULATIVELY) |
556 | return NULL_TREE; | |
557 | ||
558 | return error_mark_node; | |
559 | } | |
560 | ||
561 | /* We are using a reference VAL for its value. Bash that reference all the | |
96624a9e | 562 | way down to its lowest form. */ |
563 | ||
471086d6 | 564 | tree |
35771a9a | 565 | convert_from_reference (tree val) |
471086d6 | 566 | { |
120c0017 | 567 | if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE) |
4d698345 | 568 | return build_indirect_ref (val, NULL); |
471086d6 | 569 | return val; |
570 | } | |
dbacd3bd | 571 | |
572 | /* Implicitly convert the lvalue EXPR to another lvalue of type TOTYPE, | |
573 | preserving cv-qualification. */ | |
574 | ||
575 | tree | |
35771a9a | 576 | convert_lvalue (tree totype, tree expr) |
dbacd3bd | 577 | { |
578 | totype = cp_build_qualified_type (totype, TYPE_QUALS (TREE_TYPE (expr))); | |
579 | totype = build_reference_type (totype); | |
580 | expr = convert_to_reference (totype, expr, CONV_IMPLICIT, LOOKUP_NORMAL, | |
581 | NULL_TREE); | |
582 | return convert_from_reference (expr); | |
583 | } | |
e5dab226 | 584 | |
585 | /* Really perform an lvalue-to-rvalue conversion, including copying an | |
586 | argument of class type into a temporary. */ | |
587 | ||
588 | tree | |
589 | force_rvalue (tree expr) | |
590 | { | |
591 | if (IS_AGGR_TYPE (TREE_TYPE (expr)) && TREE_CODE (expr) != TARGET_EXPR) | |
592 | expr = ocp_convert (TREE_TYPE (expr), expr, | |
593 | CONV_IMPLICIT|CONV_FORCE_TEMP, LOOKUP_NORMAL); | |
594 | else | |
595 | expr = decay_conversion (expr); | |
596 | ||
597 | return expr; | |
598 | } | |
471086d6 | 599 | \f |
c4a8ac95 | 600 | /* C++ conversions, preference to static cast conversions. */ |
601 | ||
602 | tree | |
35771a9a | 603 | cp_convert (tree type, tree expr) |
c4a8ac95 | 604 | { |
605 | return ocp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL); | |
606 | } | |
607 | ||
b248d3f7 | 608 | /* Conversion... |
609 | ||
610 | FLAGS indicates how we should behave. */ | |
611 | ||
471086d6 | 612 | tree |
35771a9a | 613 | ocp_convert (tree type, tree expr, int convtype, int flags) |
471086d6 | 614 | { |
615 | register tree e = expr; | |
616 | register enum tree_code code = TREE_CODE (type); | |
617 | ||
1bc16cab | 618 | if (error_operand_p (e) || type == error_mark_node) |
471086d6 | 619 | return error_mark_node; |
d81e00a4 | 620 | |
5b592939 | 621 | complete_type (type); |
622 | complete_type (TREE_TYPE (expr)); | |
623 | ||
1202e392 | 624 | e = decl_constant_value (e); |
7745052b | 625 | |
2133b374 | 626 | if (IS_AGGR_TYPE (type) && (convtype & CONV_FORCE_TEMP) |
627 | /* Some internal structures (vtable_entry_type, sigtbl_ptr_type) | |
628 | don't go through finish_struct, so they don't have the synthesized | |
629 | constructors. So don't force a temporary. */ | |
630 | && TYPE_HAS_CONSTRUCTOR (type)) | |
1a3f833b | 631 | /* We need a new temporary; don't take this shortcut. */; |
632 | else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (e))) | |
ca23ec64 | 633 | { |
daf9ff67 | 634 | if (same_type_p (type, TREE_TYPE (e))) |
ca23ec64 | 635 | /* The call to fold will not always remove the NOP_EXPR as |
636 | might be expected, since if one of the types is a typedef; | |
755edffd | 637 | the comparison in fold is just equality of pointers, not a |
f699c174 | 638 | call to comptypes. We don't call fold in this case because |
639 | that can result in infinite recursion; fold will call | |
640 | convert, which will call ocp_convert, etc. */ | |
641 | return e; | |
372e0e29 | 642 | /* For complex data types, we need to perform componentwise |
643 | conversion. */ | |
644 | else if (TREE_CODE (type) == COMPLEX_TYPE) | |
645 | return fold (convert_to_complex (type, e)); | |
bdb2219e | 646 | else if (TREE_CODE (e) == TARGET_EXPR) |
647 | { | |
648 | /* Don't build a NOP_EXPR of class type. Instead, change the | |
649 | type of the temporary. Only allow this for cv-qual changes, | |
650 | though. */ | |
651 | if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (e)), | |
652 | TYPE_MAIN_VARIANT (type))) | |
653 | abort (); | |
654 | TREE_TYPE (e) = TREE_TYPE (TARGET_EXPR_SLOT (e)) = type; | |
655 | return e; | |
656 | } | |
bc4e28df | 657 | else if (TREE_ADDRESSABLE (type)) |
658 | /* We shouldn't be treating objects of ADDRESSABLE type as rvalues. */ | |
bdb2219e | 659 | abort (); |
ca23ec64 | 660 | else |
f699c174 | 661 | return fold (build1 (NOP_EXPR, type, e)); |
ca23ec64 | 662 | } |
663 | ||
d81e00a4 | 664 | if (code == VOID_TYPE && (convtype & CONV_STATIC)) |
95b2ac55 | 665 | { |
b1a8d4ce | 666 | e = convert_to_void (e, /*implicit=*/NULL); |
aeef2be5 | 667 | return e; |
95b2ac55 | 668 | } |
d81e00a4 | 669 | |
bb0726a1 | 670 | if (INTEGRAL_CODE_P (code)) |
471086d6 | 671 | { |
617abf06 | 672 | tree intype = TREE_TYPE (e); |
02d7f858 | 673 | /* enum = enum, enum = int, enum = float, (enum)pointer are all |
674 | errors. */ | |
723d9ad3 | 675 | if (TREE_CODE (type) == ENUMERAL_TYPE |
02d7f858 | 676 | && ((ARITHMETIC_TYPE_P (intype) && ! (convtype & CONV_STATIC)) |
677 | || (TREE_CODE (intype) == POINTER_TYPE))) | |
471086d6 | 678 | { |
cf103c6c | 679 | pedwarn ("conversion from `%#T' to `%#T'", intype, type); |
471086d6 | 680 | |
681 | if (flag_pedantic_errors) | |
682 | return error_mark_node; | |
683 | } | |
f3ba5c6a | 684 | if (IS_AGGR_TYPE (intype)) |
471086d6 | 685 | { |
686 | tree rval; | |
8999978b | 687 | rval = build_type_conversion (type, e); |
6495357a | 688 | if (rval) |
689 | return rval; | |
b248d3f7 | 690 | if (flags & LOOKUP_COMPLAIN) |
cf103c6c | 691 | error ("`%#T' used where a `%T' was expected", intype, type); |
b248d3f7 | 692 | if (flags & LOOKUP_SPECULATIVELY) |
693 | return NULL_TREE; | |
471086d6 | 694 | return error_mark_node; |
695 | } | |
bb0726a1 | 696 | if (code == BOOLEAN_TYPE) |
ce871053 | 697 | return cp_truthvalue_conversion (e); |
698 | ||
471086d6 | 699 | return fold (convert_to_integer (type, e)); |
700 | } | |
1bc16cab | 701 | if (POINTER_TYPE_P (type) || TYPE_PTR_TO_MEMBER_P (type)) |
35771a9a | 702 | return fold (cp_convert_to_pointer (type, e, false)); |
684b9d79 | 703 | if (code == VECTOR_TYPE) |
704 | return fold (convert_to_vector (type, e)); | |
c4a8ac95 | 705 | if (code == REAL_TYPE || code == COMPLEX_TYPE) |
471086d6 | 706 | { |
707 | if (IS_AGGR_TYPE (TREE_TYPE (e))) | |
708 | { | |
709 | tree rval; | |
8999978b | 710 | rval = build_type_conversion (type, e); |
471086d6 | 711 | if (rval) |
712 | return rval; | |
713 | else | |
b248d3f7 | 714 | if (flags & LOOKUP_COMPLAIN) |
cf103c6c | 715 | error ("`%#T' used where a floating point value was expected", |
b248d3f7 | 716 | TREE_TYPE (e)); |
471086d6 | 717 | } |
c4a8ac95 | 718 | if (code == REAL_TYPE) |
719 | return fold (convert_to_real (type, e)); | |
720 | else if (code == COMPLEX_TYPE) | |
721 | return fold (convert_to_complex (type, e)); | |
471086d6 | 722 | } |
723 | ||
724 | /* New C++ semantics: since assignment is now based on | |
725 | memberwise copying, if the rhs type is derived from the | |
726 | lhs type, then we may still do a conversion. */ | |
727 | if (IS_AGGR_TYPE_CODE (code)) | |
728 | { | |
729 | tree dtype = TREE_TYPE (e); | |
c25194fd | 730 | tree ctor = NULL_TREE; |
471086d6 | 731 | |
471086d6 | 732 | dtype = TYPE_MAIN_VARIANT (dtype); |
733 | ||
471086d6 | 734 | /* Conversion between aggregate types. New C++ semantics allow |
735 | objects of derived type to be cast to objects of base type. | |
736 | Old semantics only allowed this between pointers. | |
737 | ||
738 | There may be some ambiguity between using a constructor | |
739 | vs. using a type conversion operator when both apply. */ | |
740 | ||
0a4be248 | 741 | ctor = e; |
860740a7 | 742 | |
8c18e707 | 743 | if (abstract_virtuals_error (NULL_TREE, type)) |
744 | return error_mark_node; | |
6cbb4197 | 745 | |
0a4be248 | 746 | if ((flags & LOOKUP_ONLYCONVERTING) |
747 | && ! (IS_AGGR_TYPE (dtype) && DERIVED_FROM_P (type, dtype))) | |
fce73460 | 748 | /* For copy-initialization, first we create a temp of the proper type |
749 | with a user-defined conversion sequence, then we direct-initialize | |
750 | the target with the temp (see [dcl.init]). */ | |
751 | ctor = build_user_type_conversion (type, ctor, flags); | |
3eb89cd8 | 752 | else |
f70cb9e6 | 753 | ctor = build_special_member_call (NULL_TREE, |
754 | complete_ctor_identifier, | |
755 | build_tree_list (NULL_TREE, ctor), | |
756 | TYPE_BINFO (type), flags); | |
0a4be248 | 757 | if (ctor) |
758 | return build_cplus_new (type, ctor); | |
471086d6 | 759 | } |
760 | ||
b248d3f7 | 761 | if (flags & LOOKUP_COMPLAIN) |
cf103c6c | 762 | error ("conversion from `%T' to non-scalar type `%T' requested", |
b248d3f7 | 763 | TREE_TYPE (expr), type); |
764 | if (flags & LOOKUP_SPECULATIVELY) | |
765 | return NULL_TREE; | |
471086d6 | 766 | return error_mark_node; |
767 | } | |
768 | ||
b1a8d4ce | 769 | /* When an expression is used in a void context, its value is discarded and |
770 | no lvalue-rvalue and similar conversions happen [expr.static.cast/4, | |
771 | stmt.expr/1, expr.comma/1]. This permits dereferencing an incomplete type | |
772 | in a void context. The C++ standard does not define what an `access' to an | |
773 | object is, but there is reason to beleive that it is the lvalue to rvalue | |
774 | conversion -- if it were not, `*&*p = 1' would violate [expr]/4 in that it | |
775 | accesses `*p' not to calculate the value to be stored. But, dcl.type.cv/8 | |
776 | indicates that volatile semantics should be the same between C and C++ | |
777 | where ever possible. C leaves it implementation defined as to what | |
778 | constitutes an access to a volatile. So, we interpret `*vp' as a read of | |
779 | the volatile object `vp' points to, unless that is an incomplete type. For | |
780 | volatile references we do not do this interpretation, because that would | |
781 | make it impossible to ignore the reference return value from functions. We | |
782 | issue warnings in the confusing cases. | |
783 | ||
784 | IMPLICIT is tells us the context of an implicit void conversion. */ | |
785 | ||
786 | tree | |
35771a9a | 787 | convert_to_void (tree expr, const char *implicit) |
b1a8d4ce | 788 | { |
3d411d73 | 789 | if (expr == error_mark_node |
790 | || TREE_TYPE (expr) == error_mark_node) | |
791 | return error_mark_node; | |
b1a8d4ce | 792 | if (!TREE_TYPE (expr)) |
793 | return expr; | |
e3cfe3ce | 794 | if (VOID_TYPE_P (TREE_TYPE (expr))) |
b1a8d4ce | 795 | return expr; |
796 | switch (TREE_CODE (expr)) | |
797 | { | |
798 | case COND_EXPR: | |
799 | { | |
800 | /* The two parts of a cond expr might be separate lvalues. */ | |
801 | tree op1 = TREE_OPERAND (expr,1); | |
802 | tree op2 = TREE_OPERAND (expr,2); | |
00fa9079 | 803 | tree new_op1 = convert_to_void |
804 | (op1, (implicit && !TREE_SIDE_EFFECTS (op2) | |
805 | ? "second operand of conditional" : NULL)); | |
806 | tree new_op2 = convert_to_void | |
807 | (op2, (implicit && !TREE_SIDE_EFFECTS (op1) | |
808 | ? "third operand of conditional" : NULL)); | |
b1a8d4ce | 809 | |
1b9a507b | 810 | expr = build (COND_EXPR, TREE_TYPE (new_op1), |
69773da0 | 811 | TREE_OPERAND (expr, 0), new_op1, new_op2); |
b1a8d4ce | 812 | break; |
813 | } | |
814 | ||
815 | case COMPOUND_EXPR: | |
816 | { | |
817 | /* The second part of a compound expr contains the value. */ | |
818 | tree op1 = TREE_OPERAND (expr,1); | |
00fa9079 | 819 | tree new_op1 = convert_to_void |
820 | (op1, implicit ? "right-hand operand of comma" : NULL); | |
b1a8d4ce | 821 | |
822 | if (new_op1 != op1) | |
e907a2e9 | 823 | { |
824 | tree t = build (COMPOUND_EXPR, TREE_TYPE (new_op1), | |
825 | TREE_OPERAND (expr, 0), new_op1); | |
e907a2e9 | 826 | expr = t; |
827 | } | |
828 | ||
b1a8d4ce | 829 | break; |
830 | } | |
831 | ||
832 | case NON_LVALUE_EXPR: | |
833 | case NOP_EXPR: | |
c0af329c | 834 | /* These have already decayed to rvalue. */ |
b1a8d4ce | 835 | break; |
836 | ||
837 | case CALL_EXPR: /* we have a special meaning for volatile void fn() */ | |
838 | break; | |
839 | ||
840 | case INDIRECT_REF: | |
841 | { | |
842 | tree type = TREE_TYPE (expr); | |
843 | int is_reference = TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) | |
844 | == REFERENCE_TYPE; | |
845 | int is_volatile = TYPE_VOLATILE (type); | |
4b72716d | 846 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); |
b1a8d4ce | 847 | |
848 | if (is_volatile && !is_complete) | |
cf103c6c | 849 | warning ("object of incomplete type `%T' will not be accessed in %s", |
b1a8d4ce | 850 | type, implicit ? implicit : "void context"); |
851 | else if (is_reference && is_volatile) | |
cf103c6c | 852 | warning ("object of type `%T' will not be accessed in %s", |
b1a8d4ce | 853 | TREE_TYPE (TREE_OPERAND (expr, 0)), |
854 | implicit ? implicit : "void context"); | |
855 | if (is_reference || !is_volatile || !is_complete) | |
856 | expr = TREE_OPERAND (expr, 0); | |
857 | ||
858 | break; | |
859 | } | |
860 | ||
861 | case VAR_DECL: | |
862 | { | |
863 | /* External variables might be incomplete. */ | |
864 | tree type = TREE_TYPE (expr); | |
4b72716d | 865 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); |
b1a8d4ce | 866 | |
867 | if (TYPE_VOLATILE (type) && !is_complete) | |
cf103c6c | 868 | warning ("object `%E' of incomplete type `%T' will not be accessed in %s", |
b1a8d4ce | 869 | expr, type, implicit ? implicit : "void context"); |
870 | break; | |
871 | } | |
d9f88785 | 872 | |
b1a8d4ce | 873 | default:; |
874 | } | |
875 | { | |
876 | tree probe = expr; | |
877 | ||
878 | if (TREE_CODE (probe) == ADDR_EXPR) | |
879 | probe = TREE_OPERAND (expr, 0); | |
2e0e6579 | 880 | if (type_unknown_p (probe)) |
881 | { | |
882 | /* [over.over] enumerates the places where we can take the address | |
883 | of an overloaded function, and this is not one of them. */ | |
cf103c6c | 884 | pedwarn ("%s cannot resolve address of overloaded function", |
2e0e6579 | 885 | implicit ? implicit : "void cast"); |
886 | } | |
887 | else if (implicit && probe == expr && is_overloaded_fn (probe)) | |
b1a8d4ce | 888 | /* Only warn when there is no &. */ |
cf103c6c | 889 | warning ("%s is a reference, not call, to function `%E'", |
2e0e6579 | 890 | implicit, expr); |
b1a8d4ce | 891 | } |
892 | ||
e3cfe3ce | 893 | if (expr != error_mark_node && !VOID_TYPE_P (TREE_TYPE (expr))) |
b1a8d4ce | 894 | { |
00fa9079 | 895 | if (implicit && !TREE_SIDE_EFFECTS (expr) && warn_unused_value) |
896 | warning ("%s has no effect", implicit); | |
897 | expr = build1 (CONVERT_EXPR, void_type_node, expr); | |
b1a8d4ce | 898 | } |
899 | return expr; | |
900 | } | |
901 | ||
d81e00a4 | 902 | /* Create an expression whose value is that of EXPR, |
903 | converted to type TYPE. The TREE_TYPE of the value | |
904 | is always TYPE. This function implements all reasonable | |
905 | conversions; callers should filter out those that are | |
c4a8ac95 | 906 | not permitted by the language being compiled. |
907 | ||
908 | Most of this routine is from build_reinterpret_cast. | |
909 | ||
910 | The backend cannot call cp_convert (what was convert) because | |
911 | conversions to/from basetypes may involve memory references | |
912 | (vbases) and adding or subtracting small values (multiple | |
913 | inheritance), but it calls convert from the constant folding code | |
e0aa5007 | 914 | on subtrees of already built trees after it has ripped them apart. |
c4a8ac95 | 915 | |
916 | Also, if we ever support range variables, we'll probably also have to | |
917 | do a little bit more work. */ | |
d81e00a4 | 918 | |
919 | tree | |
35771a9a | 920 | convert (tree type, tree expr) |
d81e00a4 | 921 | { |
c4a8ac95 | 922 | tree intype; |
923 | ||
924 | if (type == error_mark_node || expr == error_mark_node) | |
925 | return error_mark_node; | |
926 | ||
c4a8ac95 | 927 | intype = TREE_TYPE (expr); |
928 | ||
6686e84d | 929 | if (POINTER_TYPE_P (type) && POINTER_TYPE_P (intype)) |
c4a8ac95 | 930 | { |
1202e392 | 931 | expr = decl_constant_value (expr); |
c4a8ac95 | 932 | return fold (build1 (NOP_EXPR, type, expr)); |
933 | } | |
934 | ||
935 | return ocp_convert (type, expr, CONV_OLD_CONVERT, | |
936 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION); | |
d81e00a4 | 937 | } |
938 | ||
c4a8ac95 | 939 | /* Like cp_convert, except permit conversions to take place which |
471086d6 | 940 | are not normally allowed due to access restrictions |
941 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 942 | |
471086d6 | 943 | tree |
35771a9a | 944 | convert_force (tree type, tree expr, int convtype) |
471086d6 | 945 | { |
946 | register tree e = expr; | |
947 | register enum tree_code code = TREE_CODE (type); | |
948 | ||
949 | if (code == REFERENCE_TYPE) | |
d81e00a4 | 950 | return fold (convert_to_reference (type, e, CONV_C_CAST, LOOKUP_COMPLAIN, |
951 | NULL_TREE)); | |
471086d6 | 952 | else if (TREE_CODE (TREE_TYPE (e)) == REFERENCE_TYPE) |
953 | e = convert_from_reference (e); | |
954 | ||
955 | if (code == POINTER_TYPE) | |
956 | return fold (convert_to_pointer_force (type, e)); | |
957 | ||
ac9386a0 | 958 | /* From typeck.c convert_for_assignment */ |
471086d6 | 959 | if (((TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE && TREE_CODE (e) == ADDR_EXPR |
960 | && TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE | |
961 | && TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE) | |
ac9386a0 | 962 | || integer_zerop (e) |
963 | || TYPE_PTRMEMFUNC_P (TREE_TYPE (e))) | |
471086d6 | 964 | && TYPE_PTRMEMFUNC_P (type)) |
965 | { | |
96624a9e | 966 | /* compatible pointer to member functions. */ |
ac9386a0 | 967 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1); |
471086d6 | 968 | } |
a74e8896 | 969 | |
c4a8ac95 | 970 | return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL); |
471086d6 | 971 | } |
972 | ||
471086d6 | 973 | /* Convert an aggregate EXPR to type XTYPE. If a conversion |
974 | exists, return the attempted conversion. This may | |
975 | return ERROR_MARK_NODE if the conversion is not | |
976 | allowed (references private members, etc). | |
977 | If no conversion exists, NULL_TREE is returned. | |
978 | ||
ce28ee2e | 979 | FIXME: Ambiguity checking is wrong. Should choose one by the implicit |
980 | object parameter, or by the second standard conversion sequence if | |
981 | that doesn't do it. This will probably wait for an overloading rewrite. | |
982 | (jason 8/9/95) */ | |
471086d6 | 983 | |
471086d6 | 984 | tree |
8999978b | 985 | build_type_conversion (tree xtype, tree expr) |
471086d6 | 986 | { |
987 | /* C++: check to see if we can convert this aggregate type | |
bcf789d7 | 988 | into the required type. */ |
8999978b | 989 | return build_user_type_conversion (xtype, expr, LOOKUP_NORMAL); |
471086d6 | 990 | } |
991 | ||
1e66592c | 992 | /* Convert the given EXPR to one of a group of types suitable for use in an |
993 | expression. DESIRES is a combination of various WANT_* flags (q.v.) | |
35771a9a | 994 | which indicates which types are suitable. If COMPLAIN is true, complain |
1e66592c | 995 | about ambiguity; otherwise, the caller will deal with it. */ |
471086d6 | 996 | |
1e66592c | 997 | tree |
35771a9a | 998 | build_expr_type_conversion (int desires, tree expr, bool complain) |
471086d6 | 999 | { |
1e66592c | 1000 | tree basetype = TREE_TYPE (expr); |
6a44e72e | 1001 | tree conv = NULL_TREE; |
bdd152ce | 1002 | tree winner = NULL_TREE; |
471086d6 | 1003 | |
954885ed | 1004 | if (expr == null_node |
1005 | && (desires & WANT_INT) | |
1006 | && !(desires & WANT_NULL)) | |
cf103c6c | 1007 | warning ("converting NULL to non-pointer type"); |
954885ed | 1008 | |
ce28ee2e | 1009 | expr = convert_from_reference (expr); |
1010 | basetype = TREE_TYPE (expr); | |
471086d6 | 1011 | |
3d411d73 | 1012 | if (basetype == error_mark_node) |
1013 | return error_mark_node; | |
1014 | ||
bdd152ce | 1015 | if (! IS_AGGR_TYPE (basetype)) |
1016 | switch (TREE_CODE (basetype)) | |
1017 | { | |
1018 | case INTEGER_TYPE: | |
954885ed | 1019 | if ((desires & WANT_NULL) && null_ptr_cst_p (expr)) |
bdd152ce | 1020 | return expr; |
1021 | /* else fall through... */ | |
1022 | ||
1023 | case BOOLEAN_TYPE: | |
1024 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1025 | case ENUMERAL_TYPE: | |
1026 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1027 | case REAL_TYPE: | |
1028 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1029 | case POINTER_TYPE: | |
1030 | return (desires & WANT_POINTER) ? expr : NULL_TREE; | |
985e9ee0 | 1031 | |
bdd152ce | 1032 | case FUNCTION_TYPE: |
1033 | case ARRAY_TYPE: | |
a681799d | 1034 | return (desires & WANT_POINTER) ? decay_conversion (expr) |
bdd152ce | 1035 | : NULL_TREE; |
1036 | default: | |
1037 | return NULL_TREE; | |
1038 | } | |
1039 | ||
1040 | /* The code for conversions from class type is currently only used for | |
1041 | delete expressions. Other expressions are handled by build_new_op. */ | |
1042 | ||
1043 | if (! TYPE_HAS_CONVERSION (basetype)) | |
1044 | return NULL_TREE; | |
1045 | ||
1046 | for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv)) | |
1047 | { | |
1048 | int win = 0; | |
1049 | tree candidate; | |
1050 | tree cand = TREE_VALUE (conv); | |
1051 | ||
1052 | if (winner && winner == cand) | |
1053 | continue; | |
1054 | ||
ef4534a3 | 1055 | candidate = non_reference (TREE_TYPE (TREE_TYPE (cand))); |
bdd152ce | 1056 | |
1057 | switch (TREE_CODE (candidate)) | |
1058 | { | |
1059 | case BOOLEAN_TYPE: | |
1060 | case INTEGER_TYPE: | |
1061 | win = (desires & WANT_INT); break; | |
1062 | case ENUMERAL_TYPE: | |
1063 | win = (desires & WANT_ENUM); break; | |
1064 | case REAL_TYPE: | |
1065 | win = (desires & WANT_FLOAT); break; | |
1066 | case POINTER_TYPE: | |
1067 | win = (desires & WANT_POINTER); break; | |
1068 | ||
1069 | default: | |
1070 | break; | |
1071 | } | |
1072 | ||
1073 | if (win) | |
1074 | { | |
1075 | if (winner) | |
1076 | { | |
1077 | if (complain) | |
1078 | { | |
cf103c6c | 1079 | error ("ambiguous default type conversion from `%T'", |
bdd152ce | 1080 | basetype); |
cf103c6c | 1081 | error (" candidate conversions include `%D' and `%D'", |
bdd152ce | 1082 | winner, cand); |
1083 | } | |
1084 | return error_mark_node; | |
1085 | } | |
1086 | else | |
1087 | winner = cand; | |
1088 | } | |
1089 | } | |
1e66592c | 1090 | |
bdd152ce | 1091 | if (winner) |
1092 | { | |
ef4534a3 | 1093 | tree type = non_reference (TREE_TYPE (TREE_TYPE (winner))); |
bdd152ce | 1094 | return build_user_type_conversion (type, expr, LOOKUP_NORMAL); |
471086d6 | 1095 | } |
1e66592c | 1096 | |
985e9ee0 | 1097 | return NULL_TREE; |
471086d6 | 1098 | } |
bc3887cf | 1099 | |
96624a9e | 1100 | /* Implements integral promotion (4.1) and float->double promotion. */ |
1101 | ||
bc3887cf | 1102 | tree |
35771a9a | 1103 | type_promotes_to (tree type) |
bc3887cf | 1104 | { |
ce28ee2e | 1105 | if (type == error_mark_node) |
1106 | return error_mark_node; | |
1107 | ||
bc3887cf | 1108 | type = TYPE_MAIN_VARIANT (type); |
bb0726a1 | 1109 | |
1110 | /* bool always promotes to int (not unsigned), even if it's the same | |
1111 | size. */ | |
028ea8b4 | 1112 | if (type == boolean_type_node) |
bb0726a1 | 1113 | type = integer_type_node; |
1114 | ||
1115 | /* Normally convert enums to int, but convert wide enums to something | |
1116 | wider. */ | |
1117 | else if (TREE_CODE (type) == ENUMERAL_TYPE | |
1118 | || type == wchar_type_node) | |
6c9497b1 | 1119 | { |
1120 | int precision = MAX (TYPE_PRECISION (type), | |
1121 | TYPE_PRECISION (integer_type_node)); | |
771d21fa | 1122 | tree totype = c_common_type_for_size (precision, 0); |
6c9497b1 | 1123 | if (TREE_UNSIGNED (type) |
1124 | && ! int_fits_type_p (TYPE_MAX_VALUE (type), totype)) | |
771d21fa | 1125 | type = c_common_type_for_size (precision, 1); |
6c9497b1 | 1126 | else |
1127 | type = totype; | |
1128 | } | |
d7aeef06 | 1129 | else if (c_promoting_integer_type_p (type)) |
bc3887cf | 1130 | { |
d0acef9e | 1131 | /* Retain unsignedness if really not getting bigger. */ |
bc3887cf | 1132 | if (TREE_UNSIGNED (type) |
d0acef9e | 1133 | && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) |
bc3887cf | 1134 | type = unsigned_type_node; |
1135 | else | |
1136 | type = integer_type_node; | |
1137 | } | |
1138 | else if (type == float_type_node) | |
1139 | type = double_type_node; | |
a681799d | 1140 | |
1141 | return type; | |
bc3887cf | 1142 | } |
668ae905 | 1143 | |
668ae905 | 1144 | /* The routines below this point are carefully written to conform to |
1145 | the standard. They use the same terminology, and follow the rules | |
1146 | closely. Although they are used only in pt.c at the moment, they | |
1147 | should presumably be used everywhere in the future. */ | |
1148 | ||
1146f179 | 1149 | /* Attempt to perform qualification conversions on EXPR to convert it |
1150 | to TYPE. Return the resulting expression, or error_mark_node if | |
1151 | the conversion was impossible. */ | |
1152 | ||
668ae905 | 1153 | tree |
35771a9a | 1154 | perform_qualification_conversions (tree type, tree expr) |
668ae905 | 1155 | { |
1bc16cab | 1156 | tree expr_type; |
1157 | ||
1158 | expr_type = TREE_TYPE (expr); | |
1159 | ||
1160 | if (TYPE_PTR_P (type) && TYPE_PTR_P (expr_type) | |
1161 | && comp_ptr_ttypes (TREE_TYPE (type), TREE_TYPE (expr_type))) | |
1162 | return build_nop (type, expr); | |
1163 | else if (TYPE_PTR_TO_MEMBER_P (type) | |
1164 | && TYPE_PTR_TO_MEMBER_P (expr_type) | |
1165 | && same_type_p (TYPE_PTRMEM_CLASS_TYPE (type), | |
1166 | TYPE_PTRMEM_CLASS_TYPE (expr_type)) | |
1167 | && comp_ptr_ttypes (TYPE_PTRMEM_POINTED_TO_TYPE (type), | |
1168 | TYPE_PTRMEM_POINTED_TO_TYPE (expr_type))) | |
1169 | return build_nop (type, expr); | |
1146f179 | 1170 | else |
1171 | return error_mark_node; | |
668ae905 | 1172 | } |