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471086d6 | 1 | /* Language-level data type conversion for GNU C++. |
fbd26352 | 2 | Copyright (C) 1987-2019 Free Software Foundation, Inc. |
471086d6 | 3 | Hacked by Michael Tiemann (tiemann@cygnus.com) |
4 | ||
6f0d25a6 | 5 | This file is part of GCC. |
471086d6 | 6 | |
6f0d25a6 | 7 | GCC is free software; you can redistribute it and/or modify |
471086d6 | 8 | it under the terms of the GNU General Public License as published by |
aa139c3f | 9 | the Free Software Foundation; either version 3, or (at your option) |
471086d6 | 10 | any later version. |
11 | ||
6f0d25a6 | 12 | GCC is distributed in the hope that it will be useful, |
471086d6 | 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 | |
aa139c3f | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
471086d6 | 20 | |
21 | ||
af86cc06 | 22 | /* This file contains the functions for converting C++ expressions |
471086d6 | 23 | to different data types. The only entry point is `convert'. |
24 | Every language front end must have a `convert' function | |
25 | but what kind of conversions it does will depend on the language. */ | |
26 | ||
27 | #include "config.h" | |
b3ef7553 | 28 | #include "system.h" |
805e22b2 | 29 | #include "coretypes.h" |
4cba6f60 | 30 | #include "target.h" |
4cba6f60 | 31 | #include "cp-tree.h" |
9ed99284 | 32 | #include "stor-layout.h" |
471086d6 | 33 | #include "flags.h" |
ca82e026 | 34 | #include "intl.h" |
471086d6 | 35 | #include "convert.h" |
30a86690 | 36 | #include "stringpool.h" |
37 | #include "attribs.h" | |
96624a9e | 38 | |
c4698a21 | 39 | static tree convert_to_pointer_force (tree, tree, tsubst_flags_t); |
ef9571e5 | 40 | static tree build_type_conversion (tree, tree); |
c4698a21 | 41 | static tree build_up_reference (tree, tree, int, tree, tsubst_flags_t); |
19b271a9 | 42 | static void diagnose_ref_binding (location_t, tree, tree, tree); |
71ccdfff | 43 | |
471086d6 | 44 | /* Change of width--truncation and extension of integers or reals-- |
45 | is represented with NOP_EXPR. Proper functioning of many things | |
46 | assumes that no other conversions can be NOP_EXPRs. | |
47 | ||
48 | Conversion between integer and pointer is represented with CONVERT_EXPR. | |
49 | Converting integer to real uses FLOAT_EXPR | |
50 | and real to integer uses FIX_TRUNC_EXPR. | |
51 | ||
52 | Here is a list of all the functions that assume that widening and | |
53 | narrowing is always done with a NOP_EXPR: | |
b981525c | 54 | In convert.c, convert_to_integer[_maybe_fold]. |
471086d6 | 55 | In c-typeck.c, build_binary_op_nodefault (boolean ops), |
653e5405 | 56 | and c_common_truthvalue_conversion. |
471086d6 | 57 | In expr.c: expand_expr, for operands of a MULT_EXPR. |
58 | In fold-const.c: fold. | |
59 | In tree.c: get_narrower and get_unwidened. | |
60 | ||
61 | C++: in multiple-inheritance, converting between pointers may involve | |
62 | adjusting them by a delta stored within the class definition. */ | |
63 | \f | |
64 | /* Subroutines of `convert'. */ | |
65 | ||
471086d6 | 66 | /* if converting pointer to pointer |
67 | if dealing with classes, check for derived->base or vice versa | |
68 | else if dealing with method pointers, delegate | |
69 | else convert blindly | |
70 | else if converting class, pass off to build_type_conversion | |
e5ead12a | 71 | else try C-style pointer conversion. */ |
96624a9e | 72 | |
471086d6 | 73 | static tree |
b981525c | 74 | cp_convert_to_pointer (tree type, tree expr, bool dofold, |
75 | tsubst_flags_t complain) | |
471086d6 | 76 | { |
cd16867a | 77 | tree intype = TREE_TYPE (expr); |
78 | enum tree_code form; | |
f82eeb87 | 79 | tree rval; |
d3a3cfb8 | 80 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
61f69bc9 | 81 | |
8bf328bf | 82 | if (intype == error_mark_node) |
83 | return error_mark_node; | |
74002e1d | 84 | |
95397ff9 | 85 | if (MAYBE_CLASS_TYPE_P (intype)) |
96624a9e | 86 | { |
96624a9e | 87 | intype = complete_type (intype); |
4b72716d | 88 | if (!COMPLETE_TYPE_P (intype)) |
96624a9e | 89 | { |
c4698a21 | 90 | if (complain & tf_error) |
4d1eda3a | 91 | error_at (loc, "can%'t convert from incomplete type %qH to %qI", |
c4698a21 | 92 | intype, type); |
96624a9e | 93 | return error_mark_node; |
94 | } | |
95 | ||
8999978b | 96 | rval = build_type_conversion (type, expr); |
96624a9e | 97 | if (rval) |
98 | { | |
c4698a21 | 99 | if ((complain & tf_error) |
100 | && rval == error_mark_node) | |
4d1eda3a | 101 | error_at (loc, "conversion of %qE from %qH to %qI is ambiguous", |
61f69bc9 | 102 | expr, intype, type); |
96624a9e | 103 | return rval; |
104 | } | |
105 | } | |
106 | ||
860740a7 | 107 | /* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */ |
c21c015b | 108 | if (TYPE_PTR_P (type) |
38281c46 | 109 | && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE |
e3cfe3ce | 110 | || VOID_TYPE_P (TREE_TYPE (type)))) |
38281c46 | 111 | { |
6ab399e8 | 112 | if (TYPE_PTRMEMFUNC_P (intype) |
113 | || TREE_CODE (intype) == METHOD_TYPE) | |
c4698a21 | 114 | return convert_member_func_to_ptr (type, expr, complain); |
c21c015b | 115 | if (TYPE_PTR_P (TREE_TYPE (expr))) |
a63bc44c | 116 | return build_nop (type, expr); |
38281c46 | 117 | intype = TREE_TYPE (expr); |
118 | } | |
119 | ||
311e42bc | 120 | if (expr == error_mark_node) |
121 | return error_mark_node; | |
122 | ||
74002e1d | 123 | form = TREE_CODE (intype); |
124 | ||
d03fa520 | 125 | if (INDIRECT_TYPE_P (intype)) |
471086d6 | 126 | { |
127 | intype = TYPE_MAIN_VARIANT (intype); | |
128 | ||
129 | if (TYPE_MAIN_VARIANT (type) != intype | |
c21c015b | 130 | && TYPE_PTR_P (type) |
471086d6 | 131 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE |
95397ff9 | 132 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (type)) |
133 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype)) | |
4a2680fc | 134 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
471086d6 | 135 | { |
136 | enum tree_code code = PLUS_EXPR; | |
4a2680fc | 137 | tree binfo; |
8999978b | 138 | tree intype_class; |
139 | tree type_class; | |
140 | bool same_p; | |
4a2680fc | 141 | |
8999978b | 142 | intype_class = TREE_TYPE (intype); |
143 | type_class = TREE_TYPE (type); | |
144 | ||
9031d10b | 145 | same_p = same_type_p (TYPE_MAIN_VARIANT (intype_class), |
8999978b | 146 | TYPE_MAIN_VARIANT (type_class)); |
147 | binfo = NULL_TREE; | |
c0af329c | 148 | /* Try derived to base conversion. */ |
8999978b | 149 | if (!same_p) |
ae260dcc | 150 | binfo = lookup_base (intype_class, type_class, ba_check, |
151 | NULL, complain); | |
8999978b | 152 | if (!same_p && !binfo) |
471086d6 | 153 | { |
c0af329c | 154 | /* Try base to derived conversion. */ |
ae260dcc | 155 | binfo = lookup_base (type_class, intype_class, ba_check, |
156 | NULL, complain); | |
471086d6 | 157 | code = MINUS_EXPR; |
158 | } | |
4a2680fc | 159 | if (binfo == error_mark_node) |
160 | return error_mark_node; | |
8999978b | 161 | if (binfo || same_p) |
471086d6 | 162 | { |
8999978b | 163 | if (binfo) |
c4698a21 | 164 | expr = build_base_path (code, expr, binfo, 0, complain); |
c0af329c | 165 | /* Add any qualifier conversions. */ |
8999978b | 166 | return build_nop (type, expr); |
471086d6 | 167 | } |
168 | } | |
471086d6 | 169 | |
1bc16cab | 170 | if (TYPE_PTRMEMFUNC_P (type)) |
bea7d742 | 171 | { |
c4698a21 | 172 | if (complain & tf_error) |
4d1eda3a | 173 | error_at (loc, "cannot convert %qE from type %qH to type %qI", |
c4698a21 | 174 | expr, intype, type); |
1bc16cab | 175 | return error_mark_node; |
176 | } | |
a17aefa2 | 177 | |
1bc16cab | 178 | return build_nop (type, expr); |
179 | } | |
05765a91 | 180 | else if ((TYPE_PTRDATAMEM_P (type) && TYPE_PTRDATAMEM_P (intype)) |
e5ead12a | 181 | || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) |
182 | return convert_ptrmem (type, expr, /*allow_inverse_p=*/false, | |
c4698a21 | 183 | /*c_cast_p=*/false, complain); |
2b77484d | 184 | else if (TYPE_PTRMEMFUNC_P (intype)) |
185 | { | |
a63bc44c | 186 | if (!warn_pmf2ptr) |
187 | { | |
188 | if (TREE_CODE (expr) == PTRMEM_CST) | |
c4698a21 | 189 | return cp_convert_to_pointer (type, PTRMEM_CST_MEMBER (expr), |
b981525c | 190 | dofold, complain); |
a63bc44c | 191 | else if (TREE_CODE (expr) == OFFSET_REF) |
192 | { | |
193 | tree object = TREE_OPERAND (expr, 0); | |
194 | return get_member_function_from_ptrfunc (&object, | |
4405c1ad | 195 | TREE_OPERAND (expr, 1), |
c4698a21 | 196 | complain); |
a63bc44c | 197 | } |
198 | } | |
d3f0af4b | 199 | if (complain & tf_error) |
4d1eda3a | 200 | error_at (loc, "cannot convert %qE from type %qH to type %qI", |
d3f0af4b | 201 | expr, intype, type); |
2b77484d | 202 | return error_mark_node; |
203 | } | |
471086d6 | 204 | |
ef434176 | 205 | if (null_ptr_cst_p (expr)) |
471086d6 | 206 | { |
2b77484d | 207 | if (TYPE_PTRMEMFUNC_P (type)) |
cb02169c | 208 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0, |
c4698a21 | 209 | /*c_cast_p=*/false, complain); |
ad63a0fc | 210 | |
106c3d67 | 211 | if (complain & tf_warning) |
212 | maybe_warn_zero_as_null_pointer_constant (expr, loc); | |
213 | ||
7ba2f86f | 214 | /* A NULL pointer-to-data-member is represented by -1, not by |
215 | zero. */ | |
216 | tree val = (TYPE_PTRDATAMEM_P (type) | |
217 | ? build_int_cst_type (type, -1) | |
218 | : build_int_cst (type, 0)); | |
219 | ||
220 | return (TREE_SIDE_EFFECTS (expr) | |
221 | ? build2 (COMPOUND_EXPR, type, expr, val) : val); | |
471086d6 | 222 | } |
05765a91 | 223 | else if (TYPE_PTRMEM_P (type) && INTEGRAL_CODE_P (form)) |
de1f960a | 224 | { |
c4698a21 | 225 | if (complain & tf_error) |
4d1eda3a | 226 | error_at (loc, "invalid conversion from %qH to %qI", intype, type); |
de1f960a | 227 | return error_mark_node; |
228 | } | |
471086d6 | 229 | |
bb0726a1 | 230 | if (INTEGRAL_CODE_P (form)) |
471086d6 | 231 | { |
c5aa1e92 | 232 | if (TYPE_PRECISION (intype) == POINTER_SIZE) |
471086d6 | 233 | return build1 (CONVERT_EXPR, type, expr); |
c4698a21 | 234 | expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr, |
235 | complain); | |
092b1d6f | 236 | /* Modes may be different but sizes should be the same. There |
237 | is supposed to be some integral type that is the same width | |
238 | as a pointer. */ | |
03b7a719 | 239 | gcc_assert (GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (TREE_TYPE (expr))) |
240 | == GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type))); | |
9031d10b | 241 | |
81cc7d9c | 242 | /* FIXME needed because convert_to_pointer_maybe_fold still folds |
243 | conversion of constants. */ | |
244 | if (!dofold) | |
245 | return build1 (CONVERT_EXPR, type, expr); | |
246 | ||
b981525c | 247 | return convert_to_pointer_maybe_fold (type, expr, dofold); |
471086d6 | 248 | } |
249 | ||
cc4d0855 | 250 | if (type_unknown_p (expr)) |
c4698a21 | 251 | return instantiate_type (type, expr, complain); |
cc4d0855 | 252 | |
c4698a21 | 253 | if (complain & tf_error) |
4d1eda3a | 254 | error_at (loc, "cannot convert %qE from type %qH to type %qI", |
c4698a21 | 255 | expr, intype, type); |
471086d6 | 256 | return error_mark_node; |
257 | } | |
258 | ||
259 | /* Like convert, except permit conversions to take place which | |
260 | are not normally allowed due to access restrictions | |
261 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 262 | |
471086d6 | 263 | static tree |
c4698a21 | 264 | convert_to_pointer_force (tree type, tree expr, tsubst_flags_t complain) |
471086d6 | 265 | { |
cd16867a | 266 | tree intype = TREE_TYPE (expr); |
267 | enum tree_code form = TREE_CODE (intype); | |
9031d10b | 268 | |
471086d6 | 269 | if (form == POINTER_TYPE) |
270 | { | |
271 | intype = TYPE_MAIN_VARIANT (intype); | |
272 | ||
273 | if (TYPE_MAIN_VARIANT (type) != intype | |
274 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE | |
95397ff9 | 275 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (type)) |
276 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype)) | |
471086d6 | 277 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
278 | { | |
279 | enum tree_code code = PLUS_EXPR; | |
4a2680fc | 280 | tree binfo; |
281 | ||
282 | binfo = lookup_base (TREE_TYPE (intype), TREE_TYPE (type), | |
ae260dcc | 283 | ba_unique, NULL, complain); |
4a2680fc | 284 | if (!binfo) |
471086d6 | 285 | { |
4a2680fc | 286 | binfo = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), |
ae260dcc | 287 | ba_unique, NULL, complain); |
4a2680fc | 288 | code = MINUS_EXPR; |
471086d6 | 289 | } |
4a2680fc | 290 | if (binfo == error_mark_node) |
291 | return error_mark_node; | |
292 | if (binfo) | |
471086d6 | 293 | { |
c4698a21 | 294 | expr = build_base_path (code, expr, binfo, 0, complain); |
653e5405 | 295 | if (expr == error_mark_node) |
296 | return error_mark_node; | |
c0af329c | 297 | /* Add any qualifier conversions. */ |
4a2680fc | 298 | if (!same_type_p (TREE_TYPE (TREE_TYPE (expr)), |
299 | TREE_TYPE (type))) | |
8999978b | 300 | expr = build_nop (type, expr); |
4a2680fc | 301 | return expr; |
471086d6 | 302 | } |
471086d6 | 303 | } |
471086d6 | 304 | } |
305 | ||
b981525c | 306 | return cp_convert_to_pointer (type, expr, /*fold*/false, complain); |
471086d6 | 307 | } |
308 | ||
309 | /* We are passing something to a function which requires a reference. | |
310 | The type we are interested in is in TYPE. The initial | |
311 | value we have to begin with is in ARG. | |
312 | ||
313 | FLAGS controls how we manage access checking. | |
ca106ab1 | 314 | DIRECT_BIND in FLAGS controls how any temporaries are generated. |
315 | If DIRECT_BIND is set, DECL is the reference we're binding to. */ | |
96624a9e | 316 | |
471086d6 | 317 | static tree |
c4698a21 | 318 | build_up_reference (tree type, tree arg, int flags, tree decl, |
319 | tsubst_flags_t complain) | |
471086d6 | 320 | { |
c76251c1 | 321 | tree rval; |
0543e7a9 | 322 | tree argtype = TREE_TYPE (arg); |
471086d6 | 323 | tree target_type = TREE_TYPE (type); |
471086d6 | 324 | |
90ad495b | 325 | gcc_assert (TYPE_REF_P (type)); |
471086d6 | 326 | |
18bede74 | 327 | if ((flags & DIRECT_BIND) && ! lvalue_p (arg)) |
471086d6 | 328 | { |
ca106ab1 | 329 | /* Create a new temporary variable. We can't just use a TARGET_EXPR |
330 | here because it needs to live as long as DECL. */ | |
c76251c1 | 331 | tree targ = arg; |
ca106ab1 | 332 | |
5ab1aaca | 333 | arg = make_temporary_var_for_ref_to_temp (decl, target_type); |
c23ebfdd | 334 | |
335 | /* Process the initializer for the declaration. */ | |
38281c46 | 336 | DECL_INITIAL (arg) = targ; |
d91303a6 | 337 | cp_finish_decl (arg, targ, /*init_const_expr_p=*/false, NULL_TREE, |
011310f7 | 338 | LOOKUP_ONLYCONVERTING|DIRECT_BIND); |
1ad432f2 | 339 | } |
049132bc | 340 | else if (!(flags & DIRECT_BIND) && ! obvalue_p (arg)) |
44189c16 | 341 | return get_target_expr_sfinae (arg, complain); |
1ad432f2 | 342 | |
ca106ab1 | 343 | /* If we had a way to wrap this up, and say, if we ever needed its |
b0df6589 | 344 | address, transform all occurrences of the register, into a memory |
345 | reference we could win better. */ | |
44189c16 | 346 | rval = cp_build_addr_expr (arg, complain); |
15e55420 | 347 | if (rval == error_mark_node) |
348 | return error_mark_node; | |
349 | ||
6686e84d | 350 | if ((flags & LOOKUP_PROTECT) |
351 | && TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type) | |
95397ff9 | 352 | && MAYBE_CLASS_TYPE_P (argtype) |
353 | && MAYBE_CLASS_TYPE_P (target_type)) | |
6686e84d | 354 | { |
7e6960e0 | 355 | /* We go through lookup_base for the access control. */ |
ae260dcc | 356 | tree binfo = lookup_base (argtype, target_type, ba_check, |
357 | NULL, complain); | |
6686e84d | 358 | if (binfo == error_mark_node) |
359 | return error_mark_node; | |
360 | if (binfo == NULL_TREE) | |
361 | return error_not_base_type (target_type, argtype); | |
c4698a21 | 362 | rval = build_base_path (PLUS_EXPR, rval, binfo, 1, complain); |
6686e84d | 363 | } |
c76251c1 | 364 | else |
365 | rval | |
c4698a21 | 366 | = convert_to_pointer_force (build_pointer_type (target_type), |
367 | rval, complain); | |
8999978b | 368 | return build_nop (type, rval); |
471086d6 | 369 | } |
370 | ||
519ba62c | 371 | /* Subroutine of convert_to_reference. REFTYPE is the target reference type. |
372 | INTYPE is the original rvalue type and DECL is an optional _DECL node | |
373 | for diagnostics. | |
9031d10b | 374 | |
519ba62c | 375 | [dcl.init.ref] says that if an rvalue is used to |
376 | initialize a reference, then the reference must be to a | |
377 | non-volatile const type. */ | |
378 | ||
379 | static void | |
19b271a9 | 380 | diagnose_ref_binding (location_t loc, tree reftype, tree intype, tree decl) |
519ba62c | 381 | { |
382 | tree ttl = TREE_TYPE (reftype); | |
9031d10b | 383 | |
e7c3e8af | 384 | if (!TYPE_REF_IS_RVALUE (reftype) |
385 | && !CP_TYPE_CONST_NON_VOLATILE_P (ttl)) | |
519ba62c | 386 | { |
387 | const char *msg; | |
388 | ||
389 | if (CP_TYPE_VOLATILE_P (ttl) && decl) | |
ca82e026 | 390 | msg = G_("initialization of volatile reference type %q#T from " |
391 | "rvalue of type %qT"); | |
519ba62c | 392 | else if (CP_TYPE_VOLATILE_P (ttl)) |
ca82e026 | 393 | msg = G_("conversion to volatile reference type %q#T " |
394 | "from rvalue of type %qT"); | |
519ba62c | 395 | else if (decl) |
ca82e026 | 396 | msg = G_("initialization of non-const reference type %q#T from " |
397 | "rvalue of type %qT"); | |
519ba62c | 398 | else |
ca82e026 | 399 | msg = G_("conversion to non-const reference type %q#T from " |
400 | "rvalue of type %qT"); | |
519ba62c | 401 | |
61f69bc9 | 402 | permerror (loc, msg, reftype, intype); |
519ba62c | 403 | } |
404 | } | |
405 | ||
471086d6 | 406 | /* For C++: Only need to do one-level references, but cannot |
407 | get tripped up on signed/unsigned differences. | |
408 | ||
d81e00a4 | 409 | DECL is either NULL_TREE or the _DECL node for a reference that is being |
410 | initialized. It can be error_mark_node if we don't know the _DECL but | |
411 | we know it's an initialization. */ | |
471086d6 | 412 | |
471086d6 | 413 | tree |
35771a9a | 414 | convert_to_reference (tree reftype, tree expr, int convtype, |
c4698a21 | 415 | int flags, tree decl, tsubst_flags_t complain) |
471086d6 | 416 | { |
cd16867a | 417 | tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype)); |
418 | tree intype; | |
471086d6 | 419 | tree rval = NULL_TREE; |
1a3f833b | 420 | tree rval_as_conversion = NULL_TREE; |
1bc16cab | 421 | bool can_convert_intype_to_type; |
d3a3cfb8 | 422 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
1a3f833b | 423 | |
9031d10b | 424 | if (TREE_CODE (type) == FUNCTION_TYPE |
d32df6a6 | 425 | && TREE_TYPE (expr) == unknown_type_node) |
66bbeb85 | 426 | expr = instantiate_type (type, expr, complain); |
0a3b29ad | 427 | |
428 | if (expr == error_mark_node) | |
429 | return error_mark_node; | |
430 | ||
431 | intype = TREE_TYPE (expr); | |
cc4d0855 | 432 | |
90ad495b | 433 | gcc_assert (!TYPE_REF_P (intype)); |
434 | gcc_assert (TYPE_REF_P (reftype)); | |
471086d6 | 435 | |
471086d6 | 436 | intype = TYPE_MAIN_VARIANT (intype); |
437 | ||
b657f346 | 438 | can_convert_intype_to_type = can_convert_standard (type, intype, complain); |
66bbeb85 | 439 | |
1bc16cab | 440 | if (!can_convert_intype_to_type |
95397ff9 | 441 | && (convtype & CONV_IMPLICIT) && MAYBE_CLASS_TYPE_P (intype) |
1a3f833b | 442 | && ! (flags & LOOKUP_NO_CONVERSION)) |
443 | { | |
444 | /* Look for a user-defined conversion to lvalue that we can use. */ | |
445 | ||
0a4be248 | 446 | rval_as_conversion |
8999978b | 447 | = build_type_conversion (reftype, expr); |
1a3f833b | 448 | |
449 | if (rval_as_conversion && rval_as_conversion != error_mark_node | |
18bede74 | 450 | && lvalue_p (rval_as_conversion)) |
1a3f833b | 451 | { |
452 | expr = rval_as_conversion; | |
453 | rval_as_conversion = NULL_TREE; | |
454 | intype = type; | |
1bc16cab | 455 | can_convert_intype_to_type = 1; |
1a3f833b | 456 | } |
457 | } | |
458 | ||
b657f346 | 459 | if (((convtype & CONV_STATIC) |
460 | && can_convert_standard (intype, type, complain)) | |
1bc16cab | 461 | || ((convtype & CONV_IMPLICIT) && can_convert_intype_to_type)) |
471086d6 | 462 | { |
c4698a21 | 463 | { |
464 | tree ttl = TREE_TYPE (reftype); | |
465 | tree ttr = lvalue_type (expr); | |
471086d6 | 466 | |
19b271a9 | 467 | if ((complain & tf_error) |
18bede74 | 468 | && ! lvalue_p (expr)) |
19b271a9 | 469 | diagnose_ref_binding (loc, reftype, intype, decl); |
9031d10b | 470 | |
c4698a21 | 471 | if (! (convtype & CONV_CONST) |
472 | && !at_least_as_qualified_p (ttl, ttr)) | |
473 | { | |
474 | if (complain & tf_error) | |
4d1eda3a | 475 | permerror (loc, "conversion from %qH to %qI discards qualifiers", |
c4698a21 | 476 | ttr, reftype); |
477 | else | |
478 | return error_mark_node; | |
479 | } | |
480 | } | |
0543e7a9 | 481 | |
c4698a21 | 482 | return build_up_reference (reftype, expr, flags, decl, complain); |
471086d6 | 483 | } |
049132bc | 484 | else if ((convtype & CONV_REINTERPRET) && obvalue_p (expr)) |
0543e7a9 | 485 | { |
486 | /* When casting an lvalue to a reference type, just convert into | |
487 | a pointer to the new type and deference it. This is allowed | |
e581f478 | 488 | by San Diego WP section 5.2.9 paragraph 12, though perhaps it |
0543e7a9 | 489 | should be done directly (jason). (int &)ri ---> *(int*)&ri */ |
e581f478 | 490 | |
3748625f | 491 | /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they |
653e5405 | 492 | meant. */ |
c4698a21 | 493 | if ((complain & tf_warning) |
c21c015b | 494 | && TYPE_PTR_P (intype) |
a09db423 | 495 | && (comptypes (TREE_TYPE (intype), type, |
496 | COMPARE_BASE | COMPARE_DERIVED))) | |
61f69bc9 | 497 | warning_at (loc, 0, "casting %qT to %qT does not dereference pointer", |
498 | intype, reftype); | |
9031d10b | 499 | |
c4698a21 | 500 | rval = cp_build_addr_expr (expr, complain); |
0543e7a9 | 501 | if (rval != error_mark_node) |
985e9ee0 | 502 | rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), |
c4698a21 | 503 | rval, 0, complain); |
0543e7a9 | 504 | if (rval != error_mark_node) |
b0722fac | 505 | rval = build1 (NOP_EXPR, reftype, rval); |
0543e7a9 | 506 | } |
0a4be248 | 507 | else |
860740a7 | 508 | { |
509 | rval = convert_for_initialization (NULL_TREE, type, expr, flags, | |
c4698a21 | 510 | ICR_CONVERTING, 0, 0, complain); |
a66fe4cb | 511 | if (rval == NULL_TREE || rval == error_mark_node) |
512 | return rval; | |
19b271a9 | 513 | if (complain & tf_error) |
514 | diagnose_ref_binding (loc, reftype, intype, decl); | |
c4698a21 | 515 | rval = build_up_reference (reftype, rval, flags, decl, complain); |
860740a7 | 516 | } |
471086d6 | 517 | |
518 | if (rval) | |
519 | { | |
96624a9e | 520 | /* If we found a way to convert earlier, then use it. */ |
471086d6 | 521 | return rval; |
522 | } | |
523 | ||
c4698a21 | 524 | if (complain & tf_error) |
4d1eda3a | 525 | error_at (loc, "cannot convert type %qH to type %qI", intype, reftype); |
b248d3f7 | 526 | |
471086d6 | 527 | return error_mark_node; |
528 | } | |
529 | ||
530 | /* We are using a reference VAL for its value. Bash that reference all the | |
96624a9e | 531 | way down to its lowest form. */ |
532 | ||
471086d6 | 533 | tree |
35771a9a | 534 | convert_from_reference (tree val) |
471086d6 | 535 | { |
73bdcca2 | 536 | if (TREE_TYPE (val) |
90ad495b | 537 | && TYPE_REF_P (TREE_TYPE (val))) |
729f89ff | 538 | { |
2fb61329 | 539 | tree t = TREE_TYPE (TREE_TYPE (val)); |
729f89ff | 540 | tree ref = build1 (INDIRECT_REF, t, val); |
9031d10b | 541 | |
3d37a176 | 542 | mark_exp_read (val); |
729f89ff | 543 | /* We *must* set TREE_READONLY when dereferencing a pointer to const, |
544 | so that we get the proper error message if the result is used | |
545 | to assign to. Also, &* is supposed to be a no-op. */ | |
546 | TREE_READONLY (ref) = CP_TYPE_CONST_P (t); | |
547 | TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t); | |
548 | TREE_SIDE_EFFECTS (ref) | |
549 | = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val)); | |
729f89ff | 550 | val = ref; |
551 | } | |
9031d10b | 552 | |
471086d6 | 553 | return val; |
554 | } | |
e5dab226 | 555 | |
556 | /* Really perform an lvalue-to-rvalue conversion, including copying an | |
557 | argument of class type into a temporary. */ | |
558 | ||
559 | tree | |
9e505437 | 560 | force_rvalue (tree expr, tsubst_flags_t complain) |
e5dab226 | 561 | { |
9e505437 | 562 | tree type = TREE_TYPE (expr); |
563 | if (MAYBE_CLASS_TYPE_P (type) && TREE_CODE (expr) != TARGET_EXPR) | |
564 | { | |
f1f41a6c | 565 | vec<tree, va_gc> *args = make_tree_vector_single (expr); |
9e505437 | 566 | expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, |
567 | &args, type, LOOKUP_NORMAL, complain); | |
568 | release_tree_vector (args); | |
569 | expr = build_cplus_new (type, expr, complain); | |
570 | } | |
e5dab226 | 571 | else |
4405c1ad | 572 | expr = decay_conversion (expr, complain); |
e5dab226 | 573 | |
574 | return expr; | |
575 | } | |
f5220369 | 576 | |
471086d6 | 577 | \f |
a1f05651 | 578 | /* If EXPR and ORIG are INTEGER_CSTs, return a version of EXPR that has |
579 | TREE_OVERFLOW set only if it is set in ORIG. Otherwise, return EXPR | |
580 | unchanged. */ | |
581 | ||
582 | static tree | |
583 | ignore_overflows (tree expr, tree orig) | |
584 | { | |
d582d140 | 585 | tree stripped_expr = tree_strip_any_location_wrapper (expr); |
586 | tree stripped_orig = tree_strip_any_location_wrapper (orig); | |
587 | ||
588 | if (TREE_CODE (stripped_expr) == INTEGER_CST | |
589 | && TREE_CODE (stripped_orig) == INTEGER_CST | |
590 | && TREE_OVERFLOW (stripped_expr) != TREE_OVERFLOW (stripped_orig)) | |
a1f05651 | 591 | { |
d582d140 | 592 | gcc_assert (!TREE_OVERFLOW (stripped_orig)); |
a1f05651 | 593 | /* Ensure constant sharing. */ |
d582d140 | 594 | stripped_expr = wide_int_to_tree (TREE_TYPE (stripped_expr), |
595 | wi::to_wide (stripped_expr)); | |
a1f05651 | 596 | } |
d582d140 | 597 | |
598 | return preserve_any_location_wrapper (stripped_expr, expr); | |
a1f05651 | 599 | } |
600 | ||
601 | /* Fold away simple conversions, but make sure TREE_OVERFLOW is set | |
602 | properly. */ | |
f5220369 | 603 | |
604 | tree | |
605 | cp_fold_convert (tree type, tree expr) | |
606 | { | |
fe565588 | 607 | tree conv; |
608 | if (TREE_TYPE (expr) == type) | |
609 | conv = expr; | |
8117a337 | 610 | else if (TREE_CODE (expr) == PTRMEM_CST |
611 | && same_type_p (TYPE_PTRMEM_CLASS_TYPE (type), | |
612 | PTRMEM_CST_CLASS (expr))) | |
fe565588 | 613 | { |
614 | /* Avoid wrapping a PTRMEM_CST in NOP_EXPR. */ | |
615 | conv = copy_node (expr); | |
616 | TREE_TYPE (conv) = type; | |
617 | } | |
8117a337 | 618 | else if (TYPE_PTRMEM_P (type)) |
619 | { | |
620 | conv = convert_ptrmem (type, expr, true, false, | |
621 | tf_warning_or_error); | |
622 | conv = cp_fully_fold (conv); | |
623 | } | |
fe565588 | 624 | else |
625 | { | |
626 | conv = fold_convert (type, expr); | |
627 | conv = ignore_overflows (conv, expr); | |
628 | } | |
a1f05651 | 629 | return conv; |
f5220369 | 630 | } |
631 | ||
c4a8ac95 | 632 | /* C++ conversions, preference to static cast conversions. */ |
633 | ||
634 | tree | |
c4698a21 | 635 | cp_convert (tree type, tree expr, tsubst_flags_t complain) |
c4a8ac95 | 636 | { |
c4698a21 | 637 | return ocp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL, complain); |
c4a8ac95 | 638 | } |
639 | ||
59dd8856 | 640 | /* C++ equivalent of convert_and_check but using cp_convert as the |
641 | conversion function. | |
642 | ||
643 | Convert EXPR to TYPE, warning about conversion problems with constants. | |
644 | Invoke this function on every expression that is converted implicitly, | |
645 | i.e. because of language rules and not because of an explicit cast. */ | |
646 | ||
647 | tree | |
c4698a21 | 648 | cp_convert_and_check (tree type, tree expr, tsubst_flags_t complain) |
59dd8856 | 649 | { |
650 | tree result; | |
651 | ||
652 | if (TREE_TYPE (expr) == type) | |
653 | return expr; | |
d2c63826 | 654 | if (expr == error_mark_node) |
655 | return expr; | |
c4698a21 | 656 | result = cp_convert (type, expr, complain); |
59dd8856 | 657 | |
c4698a21 | 658 | if ((complain & tf_warning) |
65615944 | 659 | && c_inhibit_evaluation_warnings == 0) |
660 | { | |
d2c63826 | 661 | tree folded = cp_fully_fold (expr); |
662 | tree folded_result; | |
663 | if (folded == expr) | |
664 | folded_result = result; | |
665 | else | |
666 | { | |
667 | /* Avoid bogus -Wparentheses warnings. */ | |
93a735ed | 668 | warning_sentinel w (warn_parentheses); |
bed03df1 | 669 | warning_sentinel c (warn_int_in_bool_context); |
d2c63826 | 670 | folded_result = cp_convert (type, folded, tf_none); |
671 | } | |
672 | folded_result = fold_simple (folded_result); | |
673 | if (!TREE_OVERFLOW_P (folded) | |
65615944 | 674 | && folded_result != error_mark_node) |
d3a3cfb8 | 675 | warnings_for_convert_and_check (cp_expr_loc_or_loc (expr, input_location), |
3d27a0fa | 676 | type, folded, folded_result); |
65615944 | 677 | } |
59dd8856 | 678 | |
679 | return result; | |
680 | } | |
681 | ||
b248d3f7 | 682 | /* Conversion... |
683 | ||
684 | FLAGS indicates how we should behave. */ | |
685 | ||
471086d6 | 686 | tree |
c4698a21 | 687 | ocp_convert (tree type, tree expr, int convtype, int flags, |
688 | tsubst_flags_t complain) | |
471086d6 | 689 | { |
cd16867a | 690 | tree e = expr; |
691 | enum tree_code code = TREE_CODE (type); | |
7a979707 | 692 | const char *invalid_conv_diag; |
2b3c93a3 | 693 | tree e1; |
d3a3cfb8 | 694 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
b981525c | 695 | bool dofold = (convtype & CONV_FOLD); |
471086d6 | 696 | |
1bc16cab | 697 | if (error_operand_p (e) || type == error_mark_node) |
471086d6 | 698 | return error_mark_node; |
d81e00a4 | 699 | |
5b592939 | 700 | complete_type (type); |
701 | complete_type (TREE_TYPE (expr)); | |
702 | ||
7a979707 | 703 | if ((invalid_conv_diag |
704 | = targetm.invalid_conversion (TREE_TYPE (expr), type))) | |
705 | { | |
c4698a21 | 706 | if (complain & tf_error) |
707 | error (invalid_conv_diag); | |
7a979707 | 708 | return error_mark_node; |
709 | } | |
710 | ||
ce984e5e | 711 | /* FIXME remove when moving to c_fully_fold model. */ |
0a7452a8 | 712 | if (!CLASS_TYPE_P (type)) |
f3d71480 | 713 | { |
714 | e = mark_rvalue_use (e); | |
715 | e = scalar_constant_value (e); | |
716 | } | |
7a00f939 | 717 | if (error_operand_p (e)) |
718 | return error_mark_node; | |
7745052b | 719 | |
4f55b6d2 | 720 | if (NULLPTR_TYPE_P (type) && null_ptr_cst_p (e)) |
721 | { | |
722 | if (complain & tf_warning) | |
723 | maybe_warn_zero_as_null_pointer_constant (e, loc); | |
724 | ||
725 | if (!TREE_SIDE_EFFECTS (e)) | |
726 | return nullptr_node; | |
727 | } | |
728 | ||
c821ae1a | 729 | if (MAYBE_CLASS_TYPE_P (type) && (convtype & CONV_FORCE_TEMP)) |
ceab25e5 | 730 | /* We need a new temporary; don't take this shortcut. */; |
930e8175 | 731 | else if (same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (e))) |
ca23ec64 | 732 | { |
59183fff | 733 | tree etype = TREE_TYPE (e); |
734 | if (same_type_p (type, etype)) | |
ca23ec64 | 735 | /* The call to fold will not always remove the NOP_EXPR as |
736 | might be expected, since if one of the types is a typedef; | |
755edffd | 737 | the comparison in fold is just equality of pointers, not a |
a09db423 | 738 | call to comptypes. We don't call fold in this case because |
f699c174 | 739 | that can result in infinite recursion; fold will call |
740 | convert, which will call ocp_convert, etc. */ | |
741 | return e; | |
372e0e29 | 742 | /* For complex data types, we need to perform componentwise |
653e5405 | 743 | conversion. */ |
372e0e29 | 744 | else if (TREE_CODE (type) == COMPLEX_TYPE) |
b981525c | 745 | return convert_to_complex_maybe_fold (type, e, dofold); |
76249021 | 746 | else if (VECTOR_TYPE_P (type)) |
d2c63826 | 747 | return convert_to_vector (type, e); |
bdb2219e | 748 | else if (TREE_CODE (e) == TARGET_EXPR) |
749 | { | |
750 | /* Don't build a NOP_EXPR of class type. Instead, change the | |
930e8175 | 751 | type of the temporary. */ |
59183fff | 752 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, etype)); |
bdb2219e | 753 | TREE_TYPE (e) = TREE_TYPE (TARGET_EXPR_SLOT (e)) = type; |
754 | return e; | |
755 | } | |
59183fff | 756 | else if (TREE_CODE (e) == CONSTRUCTOR) |
757 | { | |
758 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, etype)); | |
759 | TREE_TYPE (e) = type; | |
760 | return e; | |
761 | } | |
ca23ec64 | 762 | else |
092b1d6f | 763 | { |
764 | /* We shouldn't be treating objects of ADDRESSABLE type as | |
765 | rvalues. */ | |
766 | gcc_assert (!TREE_ADDRESSABLE (type)); | |
d2c63826 | 767 | return build_nop (type, e); |
092b1d6f | 768 | } |
ca23ec64 | 769 | } |
770 | ||
2b3c93a3 | 771 | e1 = targetm.convert_to_type (type, e); |
772 | if (e1) | |
773 | return e1; | |
774 | ||
d81e00a4 | 775 | if (code == VOID_TYPE && (convtype & CONV_STATIC)) |
95b2ac55 | 776 | { |
c4698a21 | 777 | e = convert_to_void (e, ICV_CAST, complain); |
aeef2be5 | 778 | return e; |
95b2ac55 | 779 | } |
d81e00a4 | 780 | |
bb0726a1 | 781 | if (INTEGRAL_CODE_P (code)) |
471086d6 | 782 | { |
617abf06 | 783 | tree intype = TREE_TYPE (e); |
a1f05651 | 784 | tree converted; |
384590d4 | 785 | |
786 | if (TREE_CODE (type) == ENUMERAL_TYPE) | |
787 | { | |
788 | /* enum = enum, enum = int, enum = float, (enum)pointer are all | |
789 | errors. */ | |
790 | if (((INTEGRAL_OR_ENUMERATION_TYPE_P (intype) | |
653e5405 | 791 | || TREE_CODE (intype) == REAL_TYPE) |
b312a686 | 792 | && ! (convtype & CONV_STATIC)) |
c21c015b | 793 | || TYPE_PTR_P (intype)) |
384590d4 | 794 | { |
c4698a21 | 795 | if (complain & tf_error) |
61f69bc9 | 796 | permerror (loc, "conversion from %q#T to %q#T", intype, type); |
c4698a21 | 797 | else |
384590d4 | 798 | return error_mark_node; |
799 | } | |
800 | ||
801 | /* [expr.static.cast] | |
802 | ||
803 | 8. A value of integral or enumeration type can be explicitly | |
804 | converted to an enumeration type. The value is unchanged if | |
805 | the original value is within the range of the enumeration | |
806 | values. Otherwise, the resulting enumeration value is | |
807 | unspecified. */ | |
d582d140 | 808 | tree val = fold_for_warn (e); |
c4698a21 | 809 | if ((complain & tf_warning) |
d582d140 | 810 | && TREE_CODE (val) == INTEGER_CST |
0116c9f8 | 811 | && ENUM_UNDERLYING_TYPE (type) |
d582d140 | 812 | && !int_fits_type_p (val, ENUM_UNDERLYING_TYPE (type))) |
61f69bc9 | 813 | warning_at (loc, OPT_Wconversion, |
814 | "the result of the conversion is unspecified because " | |
815 | "%qE is outside the range of type %qT", | |
816 | expr, type); | |
471086d6 | 817 | } |
95397ff9 | 818 | if (MAYBE_CLASS_TYPE_P (intype)) |
471086d6 | 819 | { |
820 | tree rval; | |
8999978b | 821 | rval = build_type_conversion (type, e); |
6495357a | 822 | if (rval) |
823 | return rval; | |
c4698a21 | 824 | if (complain & tf_error) |
61f69bc9 | 825 | error_at (loc, "%q#T used where a %qT was expected", intype, type); |
471086d6 | 826 | return error_mark_node; |
827 | } | |
bb0726a1 | 828 | if (code == BOOLEAN_TYPE) |
f8913d47 | 829 | { |
c21c015b | 830 | if (VOID_TYPE_P (intype)) |
61f69bc9 | 831 | { |
c4698a21 | 832 | if (complain & tf_error) |
833 | error_at (loc, | |
834 | "could not convert %qE from %<void%> to %<bool%>", | |
835 | expr); | |
61f69bc9 | 836 | return error_mark_node; |
837 | } | |
838 | ||
f8913d47 | 839 | /* We can't implicitly convert a scoped enum to bool, so convert |
840 | to the underlying type first. */ | |
841 | if (SCOPED_ENUM_P (intype) && (convtype & CONV_STATIC)) | |
172fff7b | 842 | e = build_nop (ENUM_UNDERLYING_TYPE (intype), e); |
493196c0 | 843 | if (complain & tf_warning) |
844 | return cp_truthvalue_conversion (e); | |
845 | else | |
846 | { | |
847 | /* Prevent bogus -Wint-in-bool-context warnings coming | |
848 | from c_common_truthvalue_conversion down the line. */ | |
849 | warning_sentinel w (warn_int_in_bool_context); | |
850 | return cp_truthvalue_conversion (e); | |
851 | } | |
f8913d47 | 852 | } |
ce871053 | 853 | |
b981525c | 854 | converted = convert_to_integer_maybe_fold (type, e, dofold); |
a1f05651 | 855 | |
856 | /* Ignore any integer overflow caused by the conversion. */ | |
857 | return ignore_overflows (converted, e); | |
471086d6 | 858 | } |
d03fa520 | 859 | if (INDIRECT_TYPE_P (type) || TYPE_PTRMEM_P (type)) |
b981525c | 860 | return cp_convert_to_pointer (type, e, dofold, complain); |
684b9d79 | 861 | if (code == VECTOR_TYPE) |
c37ff371 | 862 | { |
863 | tree in_vtype = TREE_TYPE (e); | |
95397ff9 | 864 | if (MAYBE_CLASS_TYPE_P (in_vtype)) |
c37ff371 | 865 | { |
866 | tree ret_val; | |
867 | ret_val = build_type_conversion (type, e); | |
653e5405 | 868 | if (ret_val) |
869 | return ret_val; | |
c4698a21 | 870 | if (complain & tf_error) |
871 | error_at (loc, "%q#T used where a %qT was expected", | |
872 | in_vtype, type); | |
653e5405 | 873 | return error_mark_node; |
c37ff371 | 874 | } |
d2c63826 | 875 | return convert_to_vector (type, e); |
c37ff371 | 876 | } |
c4a8ac95 | 877 | if (code == REAL_TYPE || code == COMPLEX_TYPE) |
471086d6 | 878 | { |
95397ff9 | 879 | if (MAYBE_CLASS_TYPE_P (TREE_TYPE (e))) |
471086d6 | 880 | { |
881 | tree rval; | |
8999978b | 882 | rval = build_type_conversion (type, e); |
471086d6 | 883 | if (rval) |
884 | return rval; | |
c4698a21 | 885 | else if (complain & tf_error) |
886 | error_at (loc, | |
887 | "%q#T used where a floating point value was expected", | |
888 | TREE_TYPE (e)); | |
471086d6 | 889 | } |
c4a8ac95 | 890 | if (code == REAL_TYPE) |
b981525c | 891 | return convert_to_real_maybe_fold (type, e, dofold); |
c4a8ac95 | 892 | else if (code == COMPLEX_TYPE) |
b981525c | 893 | return convert_to_complex_maybe_fold (type, e, dofold); |
471086d6 | 894 | } |
895 | ||
896 | /* New C++ semantics: since assignment is now based on | |
897 | memberwise copying, if the rhs type is derived from the | |
898 | lhs type, then we may still do a conversion. */ | |
95397ff9 | 899 | if (RECORD_OR_UNION_CODE_P (code)) |
471086d6 | 900 | { |
901 | tree dtype = TREE_TYPE (e); | |
c25194fd | 902 | tree ctor = NULL_TREE; |
471086d6 | 903 | |
471086d6 | 904 | dtype = TYPE_MAIN_VARIANT (dtype); |
905 | ||
471086d6 | 906 | /* Conversion between aggregate types. New C++ semantics allow |
907 | objects of derived type to be cast to objects of base type. | |
908 | Old semantics only allowed this between pointers. | |
909 | ||
910 | There may be some ambiguity between using a constructor | |
911 | vs. using a type conversion operator when both apply. */ | |
912 | ||
0a4be248 | 913 | ctor = e; |
860740a7 | 914 | |
44189c16 | 915 | if (abstract_virtuals_error_sfinae (NULL_TREE, type, complain)) |
8c18e707 | 916 | return error_mark_node; |
6cbb4197 | 917 | |
f82f1250 | 918 | if (BRACE_ENCLOSED_INITIALIZER_P (ctor)) |
c4698a21 | 919 | ctor = perform_implicit_conversion (type, ctor, complain); |
f82f1250 | 920 | else if ((flags & LOOKUP_ONLYCONVERTING) |
921 | && ! (CLASS_TYPE_P (dtype) && DERIVED_FROM_P (type, dtype))) | |
fce73460 | 922 | /* For copy-initialization, first we create a temp of the proper type |
923 | with a user-defined conversion sequence, then we direct-initialize | |
924 | the target with the temp (see [dcl.init]). */ | |
c4698a21 | 925 | ctor = build_user_type_conversion (type, ctor, flags, complain); |
3eb89cd8 | 926 | else |
f352a3fb | 927 | { |
f1f41a6c | 928 | vec<tree, va_gc> *ctor_vec = make_tree_vector_single (ctor); |
f352a3fb | 929 | ctor = build_special_member_call (NULL_TREE, |
930 | complete_ctor_identifier, | |
931 | &ctor_vec, | |
c4698a21 | 932 | type, flags, complain); |
f352a3fb | 933 | release_tree_vector (ctor_vec); |
934 | } | |
0a4be248 | 935 | if (ctor) |
c4698a21 | 936 | return build_cplus_new (type, ctor, complain); |
471086d6 | 937 | } |
938 | ||
c4698a21 | 939 | if (complain & tf_error) |
a7cc1549 | 940 | { |
941 | /* If the conversion failed and expr was an invalid use of pointer to | |
942 | member function, try to report a meaningful error. */ | |
5c874cd3 | 943 | if (invalid_nonstatic_memfn_p (loc, expr, complain)) |
a7cc1549 | 944 | /* We displayed the error message. */; |
945 | else | |
4d1eda3a | 946 | error_at (loc, "conversion from %qH to non-scalar type %qI requested", |
61f69bc9 | 947 | TREE_TYPE (expr), type); |
a7cc1549 | 948 | } |
471086d6 | 949 | return error_mark_node; |
950 | } | |
951 | ||
3ae3cb42 | 952 | /* If CALL is a call, return the callee; otherwise null. */ |
953 | ||
954 | tree | |
955 | cp_get_callee (tree call) | |
956 | { | |
957 | if (call == NULL_TREE) | |
958 | return call; | |
959 | else if (TREE_CODE (call) == CALL_EXPR) | |
960 | return CALL_EXPR_FN (call); | |
961 | else if (TREE_CODE (call) == AGGR_INIT_EXPR) | |
962 | return AGGR_INIT_EXPR_FN (call); | |
963 | return NULL_TREE; | |
964 | } | |
965 | ||
ddd2a3d4 | 966 | /* FN is the callee of a CALL_EXPR or AGGR_INIT_EXPR; return the FUNCTION_DECL |
967 | if we can. */ | |
968 | ||
969 | tree | |
ced7e116 | 970 | cp_get_fndecl_from_callee (tree fn, bool fold /* = true */) |
ddd2a3d4 | 971 | { |
972 | if (fn == NULL_TREE) | |
973 | return fn; | |
974 | if (TREE_CODE (fn) == FUNCTION_DECL) | |
975 | return fn; | |
976 | tree type = TREE_TYPE (fn); | |
977 | if (type == unknown_type_node) | |
978 | return NULL_TREE; | |
d03fa520 | 979 | gcc_assert (INDIRECT_TYPE_P (type)); |
ced7e116 | 980 | if (fold) |
981 | fn = maybe_constant_init (fn); | |
ddd2a3d4 | 982 | STRIP_NOPS (fn); |
983 | if (TREE_CODE (fn) == ADDR_EXPR) | |
984 | { | |
985 | fn = TREE_OPERAND (fn, 0); | |
986 | if (TREE_CODE (fn) == FUNCTION_DECL) | |
987 | return fn; | |
988 | } | |
989 | return NULL_TREE; | |
990 | } | |
991 | ||
992 | /* Like get_callee_fndecl, but handles AGGR_INIT_EXPR as well and uses the | |
993 | constexpr machinery. */ | |
994 | ||
995 | tree | |
996 | cp_get_callee_fndecl (tree call) | |
997 | { | |
998 | return cp_get_fndecl_from_callee (cp_get_callee (call)); | |
999 | } | |
1000 | ||
ced7e116 | 1001 | /* As above, but not using the constexpr machinery. */ |
1002 | ||
1003 | tree | |
1004 | cp_get_callee_fndecl_nofold (tree call) | |
1005 | { | |
1006 | return cp_get_fndecl_from_callee (cp_get_callee (call), false); | |
1007 | } | |
1008 | ||
ddd2a3d4 | 1009 | /* Subroutine of convert_to_void. Warn if we're discarding something with |
1010 | attribute [[nodiscard]]. */ | |
1011 | ||
1012 | static void | |
1013 | maybe_warn_nodiscard (tree expr, impl_conv_void implicit) | |
1014 | { | |
1015 | tree call = expr; | |
1016 | if (TREE_CODE (expr) == TARGET_EXPR) | |
1017 | call = TARGET_EXPR_INITIAL (expr); | |
d3a3cfb8 | 1018 | location_t loc = cp_expr_loc_or_loc (call, input_location); |
ddd2a3d4 | 1019 | tree callee = cp_get_callee (call); |
1020 | if (!callee) | |
1021 | return; | |
1022 | ||
1023 | tree type = TREE_TYPE (callee); | |
1024 | if (TYPE_PTRMEMFUNC_P (type)) | |
1025 | type = TYPE_PTRMEMFUNC_FN_TYPE (type); | |
d03fa520 | 1026 | if (INDIRECT_TYPE_P (type)) |
ddd2a3d4 | 1027 | type = TREE_TYPE (type); |
1028 | ||
1029 | tree rettype = TREE_TYPE (type); | |
1030 | tree fn = cp_get_fndecl_from_callee (callee); | |
1031 | if (implicit != ICV_CAST && fn | |
1032 | && lookup_attribute ("nodiscard", DECL_ATTRIBUTES (fn))) | |
1033 | { | |
bc35ef65 | 1034 | auto_diagnostic_group d; |
ddd2a3d4 | 1035 | if (warning_at (loc, OPT_Wunused_result, |
1036 | "ignoring return value of %qD, " | |
1037 | "declared with attribute nodiscard", fn)) | |
1038 | inform (DECL_SOURCE_LOCATION (fn), "declared here"); | |
1039 | } | |
1040 | else if (implicit != ICV_CAST | |
1041 | && lookup_attribute ("nodiscard", TYPE_ATTRIBUTES (rettype))) | |
1042 | { | |
bc35ef65 | 1043 | auto_diagnostic_group d; |
ddd2a3d4 | 1044 | if (warning_at (loc, OPT_Wunused_result, |
1045 | "ignoring returned value of type %qT, " | |
1046 | "declared with attribute nodiscard", rettype)) | |
1047 | { | |
1048 | if (fn) | |
1049 | inform (DECL_SOURCE_LOCATION (fn), | |
1050 | "in call to %qD, declared here", fn); | |
1051 | inform (DECL_SOURCE_LOCATION (TYPE_NAME (rettype)), | |
1052 | "%qT declared here", rettype); | |
1053 | } | |
1054 | } | |
1055 | else if (TREE_CODE (expr) == TARGET_EXPR | |
1056 | && lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (type))) | |
1057 | { | |
1058 | /* The TARGET_EXPR confuses do_warn_unused_result into thinking that the | |
1059 | result is used, so handle that case here. */ | |
1060 | if (fn) | |
1061 | { | |
bc35ef65 | 1062 | auto_diagnostic_group d; |
ddd2a3d4 | 1063 | if (warning_at (loc, OPT_Wunused_result, |
1064 | "ignoring return value of %qD, " | |
1065 | "declared with attribute warn_unused_result", | |
1066 | fn)) | |
1067 | inform (DECL_SOURCE_LOCATION (fn), "declared here"); | |
1068 | } | |
1069 | else | |
1070 | warning_at (loc, OPT_Wunused_result, | |
1071 | "ignoring return value of function " | |
1072 | "declared with attribute warn_unused_result"); | |
1073 | } | |
1074 | } | |
1075 | ||
b1a8d4ce | 1076 | /* When an expression is used in a void context, its value is discarded and |
1077 | no lvalue-rvalue and similar conversions happen [expr.static.cast/4, | |
1078 | stmt.expr/1, expr.comma/1]. This permits dereferencing an incomplete type | |
1079 | in a void context. The C++ standard does not define what an `access' to an | |
63eff20d | 1080 | object is, but there is reason to believe that it is the lvalue to rvalue |
b1a8d4ce | 1081 | conversion -- if it were not, `*&*p = 1' would violate [expr]/4 in that it |
1082 | accesses `*p' not to calculate the value to be stored. But, dcl.type.cv/8 | |
1083 | indicates that volatile semantics should be the same between C and C++ | |
1084 | where ever possible. C leaves it implementation defined as to what | |
1085 | constitutes an access to a volatile. So, we interpret `*vp' as a read of | |
1086 | the volatile object `vp' points to, unless that is an incomplete type. For | |
1087 | volatile references we do not do this interpretation, because that would | |
1088 | make it impossible to ignore the reference return value from functions. We | |
1089 | issue warnings in the confusing cases. | |
9031d10b | 1090 | |
dab3247a | 1091 | The IMPLICIT is ICV_CAST when the user is explicitly converting an expression |
1092 | to void via a cast. If an expression is being implicitly converted, IMPLICIT | |
1093 | indicates the context of the implicit conversion. */ | |
b1a8d4ce | 1094 | |
1095 | tree | |
dab3247a | 1096 | convert_to_void (tree expr, impl_conv_void implicit, tsubst_flags_t complain) |
b1a8d4ce | 1097 | { |
d3a3cfb8 | 1098 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
61f69bc9 | 1099 | |
9031d10b | 1100 | if (expr == error_mark_node |
3d411d73 | 1101 | || TREE_TYPE (expr) == error_mark_node) |
1102 | return error_mark_node; | |
b2af2a93 | 1103 | |
f4c5829e | 1104 | expr = maybe_undo_parenthesized_ref (expr); |
1105 | ||
c017458d | 1106 | expr = mark_discarded_use (expr); |
dab3247a | 1107 | if (implicit == ICV_CAST) |
c017458d | 1108 | /* An explicit cast to void avoids all -Wunused-but-set* warnings. */ |
f94341bb | 1109 | mark_exp_read (expr); |
b2af2a93 | 1110 | |
b1a8d4ce | 1111 | if (!TREE_TYPE (expr)) |
1112 | return expr; | |
5c874cd3 | 1113 | if (invalid_nonstatic_memfn_p (loc, expr, complain)) |
334f6ce1 | 1114 | return error_mark_node; |
ed36f1cf | 1115 | if (TREE_CODE (expr) == PSEUDO_DTOR_EXPR) |
1116 | { | |
ebd21de4 | 1117 | if (complain & tf_error) |
61f69bc9 | 1118 | error_at (loc, "pseudo-destructor is not called"); |
ed36f1cf | 1119 | return error_mark_node; |
1120 | } | |
e3cfe3ce | 1121 | if (VOID_TYPE_P (TREE_TYPE (expr))) |
b1a8d4ce | 1122 | return expr; |
1123 | switch (TREE_CODE (expr)) | |
1124 | { | |
1125 | case COND_EXPR: | |
1126 | { | |
653e5405 | 1127 | /* The two parts of a cond expr might be separate lvalues. */ |
1128 | tree op1 = TREE_OPERAND (expr,1); | |
1129 | tree op2 = TREE_OPERAND (expr,2); | |
527facbb | 1130 | bool side_effects = ((op1 && TREE_SIDE_EFFECTS (op1)) |
1131 | || TREE_SIDE_EFFECTS (op2)); | |
dab3247a | 1132 | tree new_op1, new_op2; |
527facbb | 1133 | new_op1 = NULL_TREE; |
dab3247a | 1134 | if (implicit != ICV_CAST && !side_effects) |
1135 | { | |
527facbb | 1136 | if (op1) |
1137 | new_op1 = convert_to_void (op1, ICV_SECOND_OF_COND, complain); | |
dab3247a | 1138 | new_op2 = convert_to_void (op2, ICV_THIRD_OF_COND, complain); |
1139 | } | |
1140 | else | |
1141 | { | |
527facbb | 1142 | if (op1) |
1143 | new_op1 = convert_to_void (op1, ICV_CAST, complain); | |
dab3247a | 1144 | new_op2 = convert_to_void (op2, ICV_CAST, complain); |
1145 | } | |
9031d10b | 1146 | |
527facbb | 1147 | expr = build3 (COND_EXPR, TREE_TYPE (new_op2), |
831d52a2 | 1148 | TREE_OPERAND (expr, 0), new_op1, new_op2); |
653e5405 | 1149 | break; |
b1a8d4ce | 1150 | } |
9031d10b | 1151 | |
b1a8d4ce | 1152 | case COMPOUND_EXPR: |
1153 | { | |
653e5405 | 1154 | /* The second part of a compound expr contains the value. */ |
1155 | tree op1 = TREE_OPERAND (expr,1); | |
dab3247a | 1156 | tree new_op1; |
1157 | if (implicit != ICV_CAST && !TREE_NO_WARNING (expr)) | |
1158 | new_op1 = convert_to_void (op1, ICV_RIGHT_OF_COMMA, complain); | |
1159 | else | |
1160 | new_op1 = convert_to_void (op1, ICV_CAST, complain); | |
9031d10b | 1161 | |
653e5405 | 1162 | if (new_op1 != op1) |
e907a2e9 | 1163 | { |
831d52a2 | 1164 | tree t = build2 (COMPOUND_EXPR, TREE_TYPE (new_op1), |
1165 | TREE_OPERAND (expr, 0), new_op1); | |
e907a2e9 | 1166 | expr = t; |
1167 | } | |
1168 | ||
653e5405 | 1169 | break; |
b1a8d4ce | 1170 | } |
9031d10b | 1171 | |
b1a8d4ce | 1172 | case NON_LVALUE_EXPR: |
1173 | case NOP_EXPR: | |
c0af329c | 1174 | /* These have already decayed to rvalue. */ |
b1a8d4ce | 1175 | break; |
9031d10b | 1176 | |
331bc0ad | 1177 | case CALL_EXPR: /* We have a special meaning for volatile void fn(). */ |
5461905d | 1178 | /* cdtors may return this or void, depending on |
1179 | targetm.cxx.cdtor_returns_this, but this shouldn't affect our | |
1180 | decisions here: neither nodiscard warnings (nodiscard cdtors | |
1181 | are nonsensical), nor should any constexpr or template | |
1182 | instantiations be affected by an ABI property that is, or at | |
1183 | least ought to be transparent to the language. */ | |
1184 | if (tree fn = cp_get_callee_fndecl_nofold (expr)) | |
1185 | if (DECL_CONSTRUCTOR_P (fn) || DECL_DESTRUCTOR_P (fn)) | |
1186 | return expr; | |
1187 | ||
ddd2a3d4 | 1188 | maybe_warn_nodiscard (expr, implicit); |
b1a8d4ce | 1189 | break; |
9031d10b | 1190 | |
b1a8d4ce | 1191 | case INDIRECT_REF: |
1192 | { | |
653e5405 | 1193 | tree type = TREE_TYPE (expr); |
90ad495b | 1194 | int is_reference = TYPE_REF_P (TREE_TYPE (TREE_OPERAND (expr, 0))); |
653e5405 | 1195 | int is_volatile = TYPE_VOLATILE (type); |
1196 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); | |
1197 | ||
dc02da7f | 1198 | /* Can't load the value if we don't know the type. */ |
653e5405 | 1199 | if (is_volatile && !is_complete) |
ebd21de4 | 1200 | { |
1201 | if (complain & tf_warning) | |
dab3247a | 1202 | switch (implicit) |
1203 | { | |
1204 | case ICV_CAST: | |
61f69bc9 | 1205 | warning_at (loc, 0, "conversion to void will not access " |
dab3247a | 1206 | "object of incomplete type %qT", type); |
1207 | break; | |
1208 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1209 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1210 | "incomplete type %qT in second operand " |
1211 | "of conditional expression", type); | |
1212 | break; | |
1213 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1214 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1215 | "incomplete type %qT in third operand " |
1216 | "of conditional expression", type); | |
1217 | break; | |
1218 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1219 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1220 | "incomplete type %qT in right operand of " |
1221 | "comma operator", type); | |
1222 | break; | |
1223 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1224 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1225 | "incomplete type %qT in left operand of " |
1226 | "comma operator", type); | |
1227 | break; | |
1228 | case ICV_STATEMENT: | |
61f69bc9 | 1229 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1230 | "incomplete type %qT in statement", type); |
1231 | break; | |
1232 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1233 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1234 | "incomplete type %qT in for increment " |
1235 | "expression", type); | |
1236 | break; | |
1237 | default: | |
1238 | gcc_unreachable (); | |
1239 | } | |
ebd21de4 | 1240 | } |
dc02da7f | 1241 | /* Don't load the value if this is an implicit dereference, or if |
1242 | the type needs to be handled by ctors/dtors. */ | |
dab3247a | 1243 | else if (is_volatile && is_reference) |
ebd21de4 | 1244 | { |
1245 | if (complain & tf_warning) | |
dab3247a | 1246 | switch (implicit) |
1247 | { | |
1248 | case ICV_CAST: | |
61f69bc9 | 1249 | warning_at (loc, 0, "conversion to void will not access " |
dab3247a | 1250 | "object of type %qT", type); |
1251 | break; | |
1252 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1253 | warning_at (loc, 0, "implicit dereference will not access " |
1254 | "object of type %qT in second operand of " | |
dab3247a | 1255 | "conditional expression", type); |
1256 | break; | |
1257 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1258 | warning_at (loc, 0, "implicit dereference will not access " |
1259 | "object of type %qT in third operand of " | |
dab3247a | 1260 | "conditional expression", type); |
1261 | break; | |
1262 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1263 | warning_at (loc, 0, "implicit dereference will not access " |
1264 | "object of type %qT in right operand of " | |
dab3247a | 1265 | "comma operator", type); |
1266 | break; | |
1267 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1268 | warning_at (loc, 0, "implicit dereference will not access " |
1269 | "object of type %qT in left operand of comma " | |
1270 | "operator", type); | |
dab3247a | 1271 | break; |
1272 | case ICV_STATEMENT: | |
61f69bc9 | 1273 | warning_at (loc, 0, "implicit dereference will not access " |
1274 | "object of type %qT in statement", type); | |
dab3247a | 1275 | break; |
1276 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1277 | warning_at (loc, 0, "implicit dereference will not access " |
1278 | "object of type %qT in for increment expression", | |
1279 | type); | |
dab3247a | 1280 | break; |
1281 | default: | |
1282 | gcc_unreachable (); | |
1283 | } | |
ebd21de4 | 1284 | } |
dab3247a | 1285 | else if (is_volatile && TREE_ADDRESSABLE (type)) |
1286 | { | |
1287 | if (complain & tf_warning) | |
1288 | switch (implicit) | |
1289 | { | |
1290 | case ICV_CAST: | |
61f69bc9 | 1291 | warning_at (loc, 0, "conversion to void will not access " |
dab3247a | 1292 | "object of non-trivially-copyable type %qT", |
61f69bc9 | 1293 | type); |
dab3247a | 1294 | break; |
1295 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1296 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1297 | "non-trivially-copyable type %qT in second " |
1298 | "operand of conditional expression", type); | |
1299 | break; | |
1300 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1301 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1302 | "non-trivially-copyable type %qT in third " |
1303 | "operand of conditional expression", type); | |
1304 | break; | |
1305 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1306 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1307 | "non-trivially-copyable type %qT in right " |
1308 | "operand of comma operator", type); | |
1309 | break; | |
1310 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1311 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1312 | "non-trivially-copyable type %qT in left " |
1313 | "operand of comma operator", type); | |
1314 | break; | |
1315 | case ICV_STATEMENT: | |
61f69bc9 | 1316 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1317 | "non-trivially-copyable type %qT in statement", |
61f69bc9 | 1318 | type); |
dab3247a | 1319 | break; |
1320 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1321 | warning_at (loc, 0, "indirection will not access object of " |
dab3247a | 1322 | "non-trivially-copyable type %qT in for " |
1323 | "increment expression", type); | |
1324 | break; | |
1325 | default: | |
1326 | gcc_unreachable (); | |
1327 | } | |
1328 | } | |
dc02da7f | 1329 | if (is_reference || !is_volatile || !is_complete || TREE_ADDRESSABLE (type)) |
a4d4030b | 1330 | { |
1331 | /* Emit a warning (if enabled) when the "effect-less" INDIRECT_REF | |
1332 | operation is stripped off. Note that we don't warn about | |
1333 | - an expression with TREE_NO_WARNING set. (For an example of | |
1334 | such expressions, see build_over_call in call.c.) | |
1335 | - automatic dereferencing of references, since the user cannot | |
3d177e8c | 1336 | control it. (See also warn_if_unused_value() in c-common.c.) */ |
a4d4030b | 1337 | if (warn_unused_value |
dab3247a | 1338 | && implicit != ICV_CAST |
a4d4030b | 1339 | && (complain & tf_warning) |
1340 | && !TREE_NO_WARNING (expr) | |
1341 | && !is_reference) | |
61f69bc9 | 1342 | warning_at (loc, OPT_Wunused_value, "value computed is not used"); |
a4d4030b | 1343 | expr = TREE_OPERAND (expr, 0); |
409bb09c | 1344 | if (TREE_CODE (expr) == CALL_EXPR) |
1345 | maybe_warn_nodiscard (expr, implicit); | |
a4d4030b | 1346 | } |
653e5405 | 1347 | |
1348 | break; | |
b1a8d4ce | 1349 | } |
9031d10b | 1350 | |
b1a8d4ce | 1351 | case VAR_DECL: |
1352 | { | |
653e5405 | 1353 | /* External variables might be incomplete. */ |
1354 | tree type = TREE_TYPE (expr); | |
1355 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); | |
1356 | ||
ebd21de4 | 1357 | if (TYPE_VOLATILE (type) && !is_complete && (complain & tf_warning)) |
dab3247a | 1358 | switch (implicit) |
1359 | { | |
1360 | case ICV_CAST: | |
61f69bc9 | 1361 | warning_at (loc, 0, "conversion to void will not access " |
dab3247a | 1362 | "object %qE of incomplete type %qT", expr, type); |
1363 | break; | |
1364 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1365 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1366 | "not be accessed in second operand of " | |
dab3247a | 1367 | "conditional expression", expr, type); |
1368 | break; | |
1369 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1370 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1371 | "not be accessed in third operand of " | |
dab3247a | 1372 | "conditional expression", expr, type); |
1373 | break; | |
1374 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1375 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1376 | "not be accessed in right operand of comma operator", | |
1377 | expr, type); | |
dab3247a | 1378 | break; |
1379 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1380 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1381 | "not be accessed in left operand of comma operator", | |
1382 | expr, type); | |
dab3247a | 1383 | break; |
1384 | case ICV_STATEMENT: | |
61f69bc9 | 1385 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1386 | "not be accessed in statement", expr, type); | |
dab3247a | 1387 | break; |
1388 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1389 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1390 | "not be accessed in for increment expression", | |
1391 | expr, type); | |
dab3247a | 1392 | break; |
1393 | default: | |
1394 | gcc_unreachable (); | |
1395 | } | |
1396 | ||
653e5405 | 1397 | break; |
b1a8d4ce | 1398 | } |
d9f88785 | 1399 | |
25b3017b | 1400 | case TARGET_EXPR: |
1401 | /* Don't bother with the temporary object returned from a function if | |
1fe75cf2 | 1402 | we don't use it, don't need to destroy it, and won't abort in |
1403 | assign_temp. We'll still | |
25b3017b | 1404 | allocate space for it in expand_call or declare_return_variable, |
1405 | but we don't need to track it through all the tree phases. */ | |
67bb1301 | 1406 | if (TARGET_EXPR_IMPLICIT_P (expr) |
1fe75cf2 | 1407 | && !TREE_ADDRESSABLE (TREE_TYPE (expr))) |
25b3017b | 1408 | { |
1409 | tree init = TARGET_EXPR_INITIAL (expr); | |
1410 | if (TREE_CODE (init) == AGGR_INIT_EXPR | |
1411 | && !AGGR_INIT_VIA_CTOR_P (init)) | |
1412 | { | |
c2f47e15 | 1413 | tree fn = AGGR_INIT_EXPR_FN (init); |
389dd41b | 1414 | expr = build_call_array_loc (input_location, |
ddd2a3d4 | 1415 | TREE_TYPE (TREE_TYPE |
1416 | (TREE_TYPE (fn))), | |
389dd41b | 1417 | fn, |
1418 | aggr_init_expr_nargs (init), | |
1419 | AGGR_INIT_EXPR_ARGP (init)); | |
25b3017b | 1420 | } |
1421 | } | |
ddd2a3d4 | 1422 | maybe_warn_nodiscard (expr, implicit); |
25b3017b | 1423 | break; |
1424 | ||
b1a8d4ce | 1425 | default:; |
1426 | } | |
703eb775 | 1427 | expr = resolve_nondeduced_context (expr, complain); |
b1a8d4ce | 1428 | { |
1429 | tree probe = expr; | |
9031d10b | 1430 | |
b1a8d4ce | 1431 | if (TREE_CODE (probe) == ADDR_EXPR) |
1432 | probe = TREE_OPERAND (expr, 0); | |
2e0e6579 | 1433 | if (type_unknown_p (probe)) |
1434 | { | |
1435 | /* [over.over] enumerates the places where we can take the address | |
1436 | of an overloaded function, and this is not one of them. */ | |
ebd21de4 | 1437 | if (complain & tf_error) |
dab3247a | 1438 | switch (implicit) |
1439 | { | |
1440 | case ICV_CAST: | |
61f69bc9 | 1441 | error_at (loc, "conversion to void " |
1442 | "cannot resolve address of overloaded function"); | |
dab3247a | 1443 | break; |
1444 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1445 | error_at (loc, "second operand of conditional expression " |
1446 | "cannot resolve address of overloaded function"); | |
dab3247a | 1447 | break; |
1448 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1449 | error_at (loc, "third operand of conditional expression " |
1450 | "cannot resolve address of overloaded function"); | |
dab3247a | 1451 | break; |
1452 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1453 | error_at (loc, "right operand of comma operator " |
1454 | "cannot resolve address of overloaded function"); | |
dab3247a | 1455 | break; |
1456 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1457 | error_at (loc, "left operand of comma operator " |
1458 | "cannot resolve address of overloaded function"); | |
dab3247a | 1459 | break; |
1460 | case ICV_STATEMENT: | |
61f69bc9 | 1461 | error_at (loc, "statement " |
1462 | "cannot resolve address of overloaded function"); | |
dab3247a | 1463 | break; |
1464 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1465 | error_at (loc, "for increment expression " |
1466 | "cannot resolve address of overloaded function"); | |
dab3247a | 1467 | break; |
1468 | } | |
ebd21de4 | 1469 | else |
1470 | return error_mark_node; | |
3ab4693e | 1471 | expr = void_node; |
2e0e6579 | 1472 | } |
dab3247a | 1473 | else if (implicit != ICV_CAST && probe == expr && is_overloaded_fn (probe)) |
2056769e | 1474 | { |
1475 | /* Only warn when there is no &. */ | |
ebd21de4 | 1476 | if (complain & tf_warning) |
dab3247a | 1477 | switch (implicit) |
1478 | { | |
1479 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1480 | warning_at (loc, OPT_Waddress, |
1481 | "second operand of conditional expression " | |
1482 | "is a reference, not call, to function %qE", expr); | |
dab3247a | 1483 | break; |
1484 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1485 | warning_at (loc, OPT_Waddress, |
1486 | "third operand of conditional expression " | |
1487 | "is a reference, not call, to function %qE", expr); | |
dab3247a | 1488 | break; |
1489 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1490 | warning_at (loc, OPT_Waddress, |
1491 | "right operand of comma operator " | |
1492 | "is a reference, not call, to function %qE", expr); | |
dab3247a | 1493 | break; |
1494 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1495 | warning_at (loc, OPT_Waddress, |
1496 | "left operand of comma operator " | |
1497 | "is a reference, not call, to function %qE", expr); | |
dab3247a | 1498 | break; |
1499 | case ICV_STATEMENT: | |
61f69bc9 | 1500 | warning_at (loc, OPT_Waddress, |
1501 | "statement is a reference, not call, to function %qE", | |
1502 | expr); | |
dab3247a | 1503 | break; |
1504 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1505 | warning_at (loc, OPT_Waddress, |
1506 | "for increment expression " | |
1507 | "is a reference, not call, to function %qE", expr); | |
dab3247a | 1508 | break; |
1509 | default: | |
1510 | gcc_unreachable (); | |
1511 | } | |
1512 | ||
2056769e | 1513 | if (TREE_CODE (expr) == COMPONENT_REF) |
1514 | expr = TREE_OPERAND (expr, 0); | |
1515 | } | |
b1a8d4ce | 1516 | } |
9031d10b | 1517 | |
e3cfe3ce | 1518 | if (expr != error_mark_node && !VOID_TYPE_P (TREE_TYPE (expr))) |
b1a8d4ce | 1519 | { |
dab3247a | 1520 | if (implicit != ICV_CAST |
5e2a4133 | 1521 | && warn_unused_value |
1522 | && !TREE_NO_WARNING (expr) | |
1523 | && !processing_template_decl) | |
1fe46df1 | 1524 | { |
1525 | /* The middle end does not warn about expressions that have | |
1526 | been explicitly cast to void, so we must do so here. */ | |
ebd21de4 | 1527 | if (!TREE_SIDE_EFFECTS (expr)) { |
1528 | if (complain & tf_warning) | |
dab3247a | 1529 | switch (implicit) |
1530 | { | |
1531 | case ICV_SECOND_OF_COND: | |
61f69bc9 | 1532 | warning_at (loc, OPT_Wunused_value, |
1533 | "second operand of conditional expression " | |
1534 | "has no effect"); | |
dab3247a | 1535 | break; |
1536 | case ICV_THIRD_OF_COND: | |
61f69bc9 | 1537 | warning_at (loc, OPT_Wunused_value, |
1538 | "third operand of conditional expression " | |
1539 | "has no effect"); | |
dab3247a | 1540 | break; |
1541 | case ICV_RIGHT_OF_COMMA: | |
61f69bc9 | 1542 | warning_at (loc, OPT_Wunused_value, |
1543 | "right operand of comma operator has no effect"); | |
dab3247a | 1544 | break; |
1545 | case ICV_LEFT_OF_COMMA: | |
61f69bc9 | 1546 | warning_at (loc, OPT_Wunused_value, |
1547 | "left operand of comma operator has no effect"); | |
dab3247a | 1548 | break; |
1549 | case ICV_STATEMENT: | |
61f69bc9 | 1550 | warning_at (loc, OPT_Wunused_value, |
1551 | "statement has no effect"); | |
dab3247a | 1552 | break; |
1553 | case ICV_THIRD_IN_FOR: | |
61f69bc9 | 1554 | warning_at (loc, OPT_Wunused_value, |
1555 | "for increment expression has no effect"); | |
dab3247a | 1556 | break; |
1557 | default: | |
1558 | gcc_unreachable (); | |
1559 | } | |
ebd21de4 | 1560 | } |
9031d10b | 1561 | else |
1562 | { | |
1fe46df1 | 1563 | tree e; |
1564 | enum tree_code code; | |
607a5d68 | 1565 | enum tree_code_class tclass; |
9031d10b | 1566 | |
1fe46df1 | 1567 | e = expr; |
1568 | /* We might like to warn about (say) "(int) f()", as the | |
1569 | cast has no effect, but the compiler itself will | |
1570 | generate implicit conversions under some | |
324d8f2d | 1571 | circumstances. (For example a block copy will be |
1fe46df1 | 1572 | turned into a call to "__builtin_memcpy", with a |
1573 | conversion of the return value to an appropriate | |
1574 | type.) So, to avoid false positives, we strip | |
416ce344 | 1575 | conversions. Do not use STRIP_NOPs because it will |
1576 | not strip conversions to "void", as that is not a | |
1577 | mode-preserving conversion. */ | |
1578 | while (TREE_CODE (e) == NOP_EXPR) | |
1579 | e = TREE_OPERAND (e, 0); | |
1fe46df1 | 1580 | |
1581 | code = TREE_CODE (e); | |
607a5d68 | 1582 | tclass = TREE_CODE_CLASS (code); |
1583 | if ((tclass == tcc_comparison | |
1584 | || tclass == tcc_unary | |
1585 | || (tclass == tcc_binary | |
1fe46df1 | 1586 | && !(code == MODIFY_EXPR |
1587 | || code == INIT_EXPR | |
1588 | || code == PREDECREMENT_EXPR | |
1589 | || code == PREINCREMENT_EXPR | |
1590 | || code == POSTDECREMENT_EXPR | |
9372a89d | 1591 | || code == POSTINCREMENT_EXPR)) |
1592 | || code == VEC_PERM_EXPR | |
1593 | || code == VEC_COND_EXPR) | |
ebd21de4 | 1594 | && (complain & tf_warning)) |
61f69bc9 | 1595 | warning_at (loc, OPT_Wunused_value, "value computed is not used"); |
1fe46df1 | 1596 | } |
1597 | } | |
00fa9079 | 1598 | expr = build1 (CONVERT_EXPR, void_type_node, expr); |
b1a8d4ce | 1599 | } |
de5ad4cb | 1600 | if (! TREE_SIDE_EFFECTS (expr)) |
3ab4693e | 1601 | expr = void_node; |
b1a8d4ce | 1602 | return expr; |
1603 | } | |
1604 | ||
d81e00a4 | 1605 | /* Create an expression whose value is that of EXPR, |
1606 | converted to type TYPE. The TREE_TYPE of the value | |
1607 | is always TYPE. This function implements all reasonable | |
1608 | conversions; callers should filter out those that are | |
c4a8ac95 | 1609 | not permitted by the language being compiled. |
1610 | ||
1611 | Most of this routine is from build_reinterpret_cast. | |
1612 | ||
a17c2a3a | 1613 | The back end cannot call cp_convert (what was convert) because |
c4a8ac95 | 1614 | conversions to/from basetypes may involve memory references |
1615 | (vbases) and adding or subtracting small values (multiple | |
1616 | inheritance), but it calls convert from the constant folding code | |
e0aa5007 | 1617 | on subtrees of already built trees after it has ripped them apart. |
c4a8ac95 | 1618 | |
1619 | Also, if we ever support range variables, we'll probably also have to | |
1620 | do a little bit more work. */ | |
d81e00a4 | 1621 | |
1622 | tree | |
35771a9a | 1623 | convert (tree type, tree expr) |
d81e00a4 | 1624 | { |
c4a8ac95 | 1625 | tree intype; |
1626 | ||
1627 | if (type == error_mark_node || expr == error_mark_node) | |
1628 | return error_mark_node; | |
1629 | ||
c4a8ac95 | 1630 | intype = TREE_TYPE (expr); |
1631 | ||
d03fa520 | 1632 | if (INDIRECT_TYPE_P (type) && INDIRECT_TYPE_P (intype)) |
d2c63826 | 1633 | return build_nop (type, expr); |
c4a8ac95 | 1634 | |
b981525c | 1635 | return ocp_convert (type, expr, CONV_BACKEND_CONVERT, |
c4698a21 | 1636 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION, |
1637 | tf_warning_or_error); | |
d81e00a4 | 1638 | } |
1639 | ||
c4a8ac95 | 1640 | /* Like cp_convert, except permit conversions to take place which |
471086d6 | 1641 | are not normally allowed due to access restrictions |
1642 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 1643 | |
471086d6 | 1644 | tree |
c4698a21 | 1645 | convert_force (tree type, tree expr, int convtype, tsubst_flags_t complain) |
471086d6 | 1646 | { |
cd16867a | 1647 | tree e = expr; |
1648 | enum tree_code code = TREE_CODE (type); | |
471086d6 | 1649 | |
1650 | if (code == REFERENCE_TYPE) | |
d2c63826 | 1651 | return convert_to_reference (type, e, CONV_C_CAST, 0, |
1652 | NULL_TREE, complain); | |
471086d6 | 1653 | |
1654 | if (code == POINTER_TYPE) | |
d2c63826 | 1655 | return convert_to_pointer_force (type, e, complain); |
471086d6 | 1656 | |
ac9386a0 | 1657 | /* From typeck.c convert_for_assignment */ |
c21c015b | 1658 | if (((TYPE_PTR_P (TREE_TYPE (e)) && TREE_CODE (e) == ADDR_EXPR |
471086d6 | 1659 | && TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE) |
ac9386a0 | 1660 | || integer_zerop (e) |
1661 | || TYPE_PTRMEMFUNC_P (TREE_TYPE (e))) | |
471086d6 | 1662 | && TYPE_PTRMEMFUNC_P (type)) |
cb02169c | 1663 | /* compatible pointer to member functions. */ |
1664 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1, | |
c4698a21 | 1665 | /*c_cast_p=*/1, complain); |
a74e8896 | 1666 | |
c4698a21 | 1667 | return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL, complain); |
471086d6 | 1668 | } |
1669 | ||
471086d6 | 1670 | /* Convert an aggregate EXPR to type XTYPE. If a conversion |
1671 | exists, return the attempted conversion. This may | |
1672 | return ERROR_MARK_NODE if the conversion is not | |
1673 | allowed (references private members, etc). | |
1674 | If no conversion exists, NULL_TREE is returned. | |
1675 | ||
ce28ee2e | 1676 | FIXME: Ambiguity checking is wrong. Should choose one by the implicit |
1677 | object parameter, or by the second standard conversion sequence if | |
1678 | that doesn't do it. This will probably wait for an overloading rewrite. | |
1679 | (jason 8/9/95) */ | |
471086d6 | 1680 | |
ef9571e5 | 1681 | static tree |
8999978b | 1682 | build_type_conversion (tree xtype, tree expr) |
471086d6 | 1683 | { |
1684 | /* C++: check to see if we can convert this aggregate type | |
bcf789d7 | 1685 | into the required type. */ |
66bbeb85 | 1686 | return build_user_type_conversion (xtype, expr, LOOKUP_NORMAL, |
1687 | tf_warning_or_error); | |
471086d6 | 1688 | } |
1689 | ||
1e66592c | 1690 | /* Convert the given EXPR to one of a group of types suitable for use in an |
1691 | expression. DESIRES is a combination of various WANT_* flags (q.v.) | |
35771a9a | 1692 | which indicates which types are suitable. If COMPLAIN is true, complain |
1e66592c | 1693 | about ambiguity; otherwise, the caller will deal with it. */ |
471086d6 | 1694 | |
1e66592c | 1695 | tree |
35771a9a | 1696 | build_expr_type_conversion (int desires, tree expr, bool complain) |
471086d6 | 1697 | { |
1e66592c | 1698 | tree basetype = TREE_TYPE (expr); |
6a44e72e | 1699 | tree conv = NULL_TREE; |
bdd152ce | 1700 | tree winner = NULL_TREE; |
471086d6 | 1701 | |
d76863c8 | 1702 | if (null_node_p (expr) |
9031d10b | 1703 | && (desires & WANT_INT) |
954885ed | 1704 | && !(desires & WANT_NULL)) |
db30b351 | 1705 | { |
be1e7283 | 1706 | location_t loc = |
db30b351 | 1707 | expansion_point_location_if_in_system_header (input_location); |
1708 | ||
1709 | warning_at (loc, OPT_Wconversion_null, | |
1710 | "converting NULL to non-pointer type"); | |
1711 | } | |
9031d10b | 1712 | |
3d411d73 | 1713 | if (basetype == error_mark_node) |
1714 | return error_mark_node; | |
1715 | ||
95397ff9 | 1716 | if (! MAYBE_CLASS_TYPE_P (basetype)) |
bdd152ce | 1717 | switch (TREE_CODE (basetype)) |
1718 | { | |
1719 | case INTEGER_TYPE: | |
954885ed | 1720 | if ((desires & WANT_NULL) && null_ptr_cst_p (expr)) |
bdd152ce | 1721 | return expr; |
e3533433 | 1722 | /* fall through. */ |
bdd152ce | 1723 | |
1724 | case BOOLEAN_TYPE: | |
1725 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1726 | case ENUMERAL_TYPE: | |
1727 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1728 | case REAL_TYPE: | |
1729 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1730 | case POINTER_TYPE: | |
1731 | return (desires & WANT_POINTER) ? expr : NULL_TREE; | |
9031d10b | 1732 | |
bdd152ce | 1733 | case FUNCTION_TYPE: |
1734 | case ARRAY_TYPE: | |
4405c1ad | 1735 | return (desires & WANT_POINTER) ? decay_conversion (expr, |
1736 | tf_warning_or_error) | |
653e5405 | 1737 | : NULL_TREE; |
96ec9e30 | 1738 | |
64ec1ad6 | 1739 | case COMPLEX_TYPE: |
96ec9e30 | 1740 | case VECTOR_TYPE: |
64ec1ad6 | 1741 | if ((desires & WANT_VECTOR_OR_COMPLEX) == 0) |
96ec9e30 | 1742 | return NULL_TREE; |
1743 | switch (TREE_CODE (TREE_TYPE (basetype))) | |
1744 | { | |
1745 | case INTEGER_TYPE: | |
1746 | case BOOLEAN_TYPE: | |
1747 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1748 | case ENUMERAL_TYPE: | |
1749 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1750 | case REAL_TYPE: | |
1751 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1752 | default: | |
1753 | return NULL_TREE; | |
1754 | } | |
1755 | ||
bdd152ce | 1756 | default: |
1757 | return NULL_TREE; | |
1758 | } | |
1759 | ||
1760 | /* The code for conversions from class type is currently only used for | |
1761 | delete expressions. Other expressions are handled by build_new_op. */ | |
a5f2d620 | 1762 | if (!complete_type_or_maybe_complain (basetype, expr, complain)) |
f8182e08 | 1763 | return error_mark_node; |
1764 | if (!TYPE_HAS_CONVERSION (basetype)) | |
bdd152ce | 1765 | return NULL_TREE; |
1766 | ||
9960d752 | 1767 | for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv)) |
bdd152ce | 1768 | { |
1769 | int win = 0; | |
1770 | tree candidate; | |
1771 | tree cand = TREE_VALUE (conv); | |
6767ca9a | 1772 | cand = OVL_FIRST (cand); |
bdd152ce | 1773 | |
1774 | if (winner && winner == cand) | |
1775 | continue; | |
1776 | ||
cf7aa2e5 | 1777 | if (DECL_NONCONVERTING_P (cand)) |
1778 | continue; | |
1779 | ||
ef4534a3 | 1780 | candidate = non_reference (TREE_TYPE (TREE_TYPE (cand))); |
bdd152ce | 1781 | |
1782 | switch (TREE_CODE (candidate)) | |
1783 | { | |
1784 | case BOOLEAN_TYPE: | |
1785 | case INTEGER_TYPE: | |
1786 | win = (desires & WANT_INT); break; | |
1787 | case ENUMERAL_TYPE: | |
1788 | win = (desires & WANT_ENUM); break; | |
1789 | case REAL_TYPE: | |
1790 | win = (desires & WANT_FLOAT); break; | |
1791 | case POINTER_TYPE: | |
1792 | win = (desires & WANT_POINTER); break; | |
1793 | ||
64ec1ad6 | 1794 | case COMPLEX_TYPE: |
96ec9e30 | 1795 | case VECTOR_TYPE: |
64ec1ad6 | 1796 | if ((desires & WANT_VECTOR_OR_COMPLEX) == 0) |
96ec9e30 | 1797 | break; |
1798 | switch (TREE_CODE (TREE_TYPE (candidate))) | |
1799 | { | |
1800 | case BOOLEAN_TYPE: | |
1801 | case INTEGER_TYPE: | |
1802 | win = (desires & WANT_INT); break; | |
1803 | case ENUMERAL_TYPE: | |
1804 | win = (desires & WANT_ENUM); break; | |
1805 | case REAL_TYPE: | |
1806 | win = (desires & WANT_FLOAT); break; | |
1807 | default: | |
1808 | break; | |
1809 | } | |
1810 | break; | |
1811 | ||
bdd152ce | 1812 | default: |
9c4c1195 | 1813 | /* A wildcard could be instantiated to match any desired |
1814 | type, but we can't deduce the template argument. */ | |
1815 | if (WILDCARD_TYPE_P (candidate)) | |
1816 | win = true; | |
bdd152ce | 1817 | break; |
1818 | } | |
1819 | ||
1820 | if (win) | |
1821 | { | |
9c4c1195 | 1822 | if (TREE_CODE (cand) == TEMPLATE_DECL) |
1823 | { | |
1824 | if (complain) | |
1825 | error ("default type conversion can't deduce template" | |
1826 | " argument for %qD", cand); | |
1827 | return error_mark_node; | |
1828 | } | |
1829 | ||
bdd152ce | 1830 | if (winner) |
1831 | { | |
609c541f | 1832 | tree winner_type |
1833 | = non_reference (TREE_TYPE (TREE_TYPE (winner))); | |
1834 | ||
1835 | if (!same_type_ignoring_top_level_qualifiers_p (winner_type, | |
1836 | candidate)) | |
bdd152ce | 1837 | { |
609c541f | 1838 | if (complain) |
1839 | { | |
1840 | error ("ambiguous default type conversion from %qT", | |
1841 | basetype); | |
392214f6 | 1842 | inform (input_location, |
1843 | " candidate conversions include %qD and %qD", | |
1844 | winner, cand); | |
609c541f | 1845 | } |
1846 | return error_mark_node; | |
bdd152ce | 1847 | } |
bdd152ce | 1848 | } |
609c541f | 1849 | |
1850 | winner = cand; | |
bdd152ce | 1851 | } |
1852 | } | |
1e66592c | 1853 | |
bdd152ce | 1854 | if (winner) |
1855 | { | |
ef4534a3 | 1856 | tree type = non_reference (TREE_TYPE (TREE_TYPE (winner))); |
66bbeb85 | 1857 | return build_user_type_conversion (type, expr, LOOKUP_NORMAL, |
1858 | tf_warning_or_error); | |
471086d6 | 1859 | } |
1e66592c | 1860 | |
985e9ee0 | 1861 | return NULL_TREE; |
471086d6 | 1862 | } |
bc3887cf | 1863 | |
96624a9e | 1864 | /* Implements integral promotion (4.1) and float->double promotion. */ |
1865 | ||
bc3887cf | 1866 | tree |
35771a9a | 1867 | type_promotes_to (tree type) |
bc3887cf | 1868 | { |
2b3c93a3 | 1869 | tree promoted_type; |
1870 | ||
ce28ee2e | 1871 | if (type == error_mark_node) |
1872 | return error_mark_node; | |
1873 | ||
bc3887cf | 1874 | type = TYPE_MAIN_VARIANT (type); |
bb0726a1 | 1875 | |
2b3c93a3 | 1876 | /* Check for promotions of target-defined types first. */ |
1877 | promoted_type = targetm.promoted_type (type); | |
1878 | if (promoted_type) | |
1879 | return promoted_type; | |
1880 | ||
bb0726a1 | 1881 | /* bool always promotes to int (not unsigned), even if it's the same |
1882 | size. */ | |
9e1a8234 | 1883 | if (TREE_CODE (type) == BOOLEAN_TYPE) |
bb0726a1 | 1884 | type = integer_type_node; |
1885 | ||
1886 | /* Normally convert enums to int, but convert wide enums to something | |
74b777e5 | 1887 | wider. Scoped enums don't promote, but pretend they do for backward |
1888 | ABI bug compatibility wrt varargs. */ | |
bb0726a1 | 1889 | else if (TREE_CODE (type) == ENUMERAL_TYPE |
82362779 | 1890 | || type == char8_type_node |
924bbf02 | 1891 | || type == char16_type_node |
1892 | || type == char32_type_node | |
bb0726a1 | 1893 | || type == wchar_type_node) |
6c9497b1 | 1894 | { |
c042ba6f | 1895 | tree prom = type; |
1896 | ||
1897 | if (TREE_CODE (type) == ENUMERAL_TYPE) | |
1898 | { | |
1899 | prom = ENUM_UNDERLYING_TYPE (prom); | |
1900 | if (!ENUM_IS_SCOPED (type) | |
1901 | && ENUM_FIXED_UNDERLYING_TYPE_P (type)) | |
1902 | { | |
1903 | /* ISO C++17, 7.6/4. A prvalue of an unscoped enumeration type | |
1904 | whose underlying type is fixed (10.2) can be converted to a | |
1905 | prvalue of its underlying type. Moreover, if integral promotion | |
1906 | can be applied to its underlying type, a prvalue of an unscoped | |
1907 | enumeration type whose underlying type is fixed can also be | |
1908 | converted to a prvalue of the promoted underlying type. */ | |
1909 | return type_promotes_to (prom); | |
1910 | } | |
1911 | } | |
1912 | ||
6c9497b1 | 1913 | int precision = MAX (TYPE_PRECISION (type), |
1914 | TYPE_PRECISION (integer_type_node)); | |
771d21fa | 1915 | tree totype = c_common_type_for_size (precision, 0); |
74b777e5 | 1916 | if (TYPE_UNSIGNED (prom) |
1917 | && ! int_fits_type_p (TYPE_MAX_VALUE (prom), totype)) | |
1918 | prom = c_common_type_for_size (precision, 1); | |
1919 | else | |
1920 | prom = totype; | |
72fc0f64 | 1921 | if (SCOPED_ENUM_P (type)) |
74b777e5 | 1922 | { |
1923 | if (abi_version_crosses (6) | |
1924 | && TYPE_MODE (prom) != TYPE_MODE (type)) | |
1925 | warning (OPT_Wabi, "scoped enum %qT passed through ... as " | |
2f6d557f | 1926 | "%qT before %<-fabi-version=6%>, %qT after", |
74b777e5 | 1927 | type, prom, ENUM_UNDERLYING_TYPE (type)); |
1928 | if (!abi_version_at_least (6)) | |
1929 | type = prom; | |
1930 | } | |
6c9497b1 | 1931 | else |
74b777e5 | 1932 | type = prom; |
6c9497b1 | 1933 | } |
d7aeef06 | 1934 | else if (c_promoting_integer_type_p (type)) |
bc3887cf | 1935 | { |
d0acef9e | 1936 | /* Retain unsignedness if really not getting bigger. */ |
78a8ed03 | 1937 | if (TYPE_UNSIGNED (type) |
d0acef9e | 1938 | && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) |
bc3887cf | 1939 | type = unsigned_type_node; |
1940 | else | |
1941 | type = integer_type_node; | |
1942 | } | |
1943 | else if (type == float_type_node) | |
1944 | type = double_type_node; | |
9031d10b | 1945 | |
a681799d | 1946 | return type; |
bc3887cf | 1947 | } |
668ae905 | 1948 | |
668ae905 | 1949 | /* The routines below this point are carefully written to conform to |
1950 | the standard. They use the same terminology, and follow the rules | |
1951 | closely. Although they are used only in pt.c at the moment, they | |
1952 | should presumably be used everywhere in the future. */ | |
1953 | ||
0a8a2108 | 1954 | /* True iff EXPR can be converted to TYPE via a qualification conversion. |
1955 | Callers should check for identical types before calling this function. */ | |
1956 | ||
1957 | bool | |
1958 | can_convert_qual (tree type, tree expr) | |
1959 | { | |
1960 | tree expr_type = TREE_TYPE (expr); | |
1961 | gcc_assert (!same_type_p (type, expr_type)); | |
1962 | ||
1963 | if (TYPE_PTR_P (type) && TYPE_PTR_P (expr_type)) | |
1964 | return comp_ptr_ttypes (TREE_TYPE (type), TREE_TYPE (expr_type)); | |
1965 | else if (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (expr_type)) | |
1966 | return (same_type_p (TYPE_PTRMEM_CLASS_TYPE (type), | |
1967 | TYPE_PTRMEM_CLASS_TYPE (expr_type)) | |
1968 | && comp_ptr_ttypes (TYPE_PTRMEM_POINTED_TO_TYPE (type), | |
1969 | TYPE_PTRMEM_POINTED_TO_TYPE (expr_type))); | |
1970 | else | |
1971 | return false; | |
1972 | } | |
1973 | ||
1146f179 | 1974 | /* Attempt to perform qualification conversions on EXPR to convert it |
1975 | to TYPE. Return the resulting expression, or error_mark_node if | |
bc190687 | 1976 | the conversion was impossible. Since this is only used by |
1977 | convert_nontype_argument, we fold the conversion. */ | |
1146f179 | 1978 | |
9031d10b | 1979 | tree |
35771a9a | 1980 | perform_qualification_conversions (tree type, tree expr) |
668ae905 | 1981 | { |
1bc16cab | 1982 | tree expr_type; |
1983 | ||
1984 | expr_type = TREE_TYPE (expr); | |
1985 | ||
3b087710 | 1986 | if (same_type_p (type, expr_type)) |
1987 | return expr; | |
0a8a2108 | 1988 | else if (can_convert_qual (type, expr)) |
bc190687 | 1989 | return cp_fold_convert (type, expr); |
1146f179 | 1990 | else |
1991 | return error_mark_node; | |
668ae905 | 1992 | } |
6d02e6b2 | 1993 | |
1994 | /* True iff T is a transaction-safe function type. */ | |
1995 | ||
1996 | bool | |
1997 | tx_safe_fn_type_p (tree t) | |
1998 | { | |
1999 | if (TREE_CODE (t) != FUNCTION_TYPE | |
2000 | && TREE_CODE (t) != METHOD_TYPE) | |
2001 | return false; | |
2002 | return !!lookup_attribute ("transaction_safe", TYPE_ATTRIBUTES (t)); | |
2003 | } | |
2004 | ||
2005 | /* Return the transaction-unsafe variant of transaction-safe function type | |
2006 | T. */ | |
2007 | ||
2008 | tree | |
2009 | tx_unsafe_fn_variant (tree t) | |
2010 | { | |
2011 | gcc_assert (tx_safe_fn_type_p (t)); | |
2012 | tree attrs = remove_attribute ("transaction_safe", | |
2013 | TYPE_ATTRIBUTES (t)); | |
2014 | return cp_build_type_attribute_variant (t, attrs); | |
2015 | } | |
2016 | ||
2017 | /* Return true iff FROM can convert to TO by a transaction-safety | |
2018 | conversion. */ | |
2019 | ||
2e9e9363 | 2020 | static bool |
6d02e6b2 | 2021 | can_convert_tx_safety (tree to, tree from) |
2022 | { | |
2023 | return (flag_tm && tx_safe_fn_type_p (from) | |
2024 | && same_type_p (to, tx_unsafe_fn_variant (from))); | |
2025 | } | |
2e9e9363 | 2026 | |
2027 | /* Return true iff FROM can convert to TO by dropping noexcept. */ | |
2028 | ||
2029 | static bool | |
2030 | noexcept_conv_p (tree to, tree from) | |
2031 | { | |
2032 | if (!flag_noexcept_type) | |
2033 | return false; | |
2034 | ||
2035 | tree t = non_reference (to); | |
2036 | tree f = from; | |
2037 | if (TYPE_PTRMEMFUNC_P (t) | |
2038 | && TYPE_PTRMEMFUNC_P (f)) | |
2039 | { | |
2040 | t = TYPE_PTRMEMFUNC_FN_TYPE (t); | |
2041 | f = TYPE_PTRMEMFUNC_FN_TYPE (f); | |
2042 | } | |
90ad495b | 2043 | if (TYPE_PTR_P (t) |
2044 | && TYPE_PTR_P (f)) | |
2e9e9363 | 2045 | { |
2046 | t = TREE_TYPE (t); | |
2047 | f = TREE_TYPE (f); | |
2048 | } | |
2049 | tree_code code = TREE_CODE (f); | |
2050 | if (TREE_CODE (t) != code) | |
2051 | return false; | |
2052 | if (code != FUNCTION_TYPE && code != METHOD_TYPE) | |
2053 | return false; | |
2054 | if (!type_throw_all_p (t) | |
2055 | || type_throw_all_p (f)) | |
2056 | return false; | |
2057 | tree v = build_exception_variant (f, NULL_TREE); | |
2058 | return same_type_p (t, v); | |
2059 | } | |
2060 | ||
2061 | /* Return true iff FROM can convert to TO by a function pointer conversion. */ | |
2062 | ||
2063 | bool | |
2064 | fnptr_conv_p (tree to, tree from) | |
2065 | { | |
2066 | tree t = non_reference (to); | |
2067 | tree f = from; | |
2068 | if (TYPE_PTRMEMFUNC_P (t) | |
2069 | && TYPE_PTRMEMFUNC_P (f)) | |
2070 | { | |
2071 | t = TYPE_PTRMEMFUNC_FN_TYPE (t); | |
2072 | f = TYPE_PTRMEMFUNC_FN_TYPE (f); | |
2073 | } | |
90ad495b | 2074 | if (TYPE_PTR_P (t) |
2075 | && TYPE_PTR_P (f)) | |
2e9e9363 | 2076 | { |
2077 | t = TREE_TYPE (t); | |
2078 | f = TREE_TYPE (f); | |
2079 | } | |
2080 | ||
2081 | return (noexcept_conv_p (t, f) | |
2082 | || can_convert_tx_safety (t, f)); | |
2083 | } | |
2084 | ||
2104a0fd | 2085 | /* Return FN with any NOP_EXPRs stripped that represent function pointer |
2086 | conversions or conversions to the same type. */ | |
2e9e9363 | 2087 | |
2088 | tree | |
2089 | strip_fnptr_conv (tree fn) | |
2090 | { | |
2091 | while (TREE_CODE (fn) == NOP_EXPR) | |
2092 | { | |
2093 | tree op = TREE_OPERAND (fn, 0); | |
2104a0fd | 2094 | tree ft = TREE_TYPE (fn); |
2095 | tree ot = TREE_TYPE (op); | |
2096 | if (same_type_p (ft, ot) | |
2097 | || fnptr_conv_p (ft, ot)) | |
2e9e9363 | 2098 | fn = op; |
2099 | else | |
2100 | break; | |
2101 | } | |
2102 | return fn; | |
2103 | } |