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8d08fdba | 1 | /* Language-level data type conversion for GNU C++. |
a5544970 | 2 | Copyright (C) 1987-2019 Free Software Foundation, Inc. |
8d08fdba MS |
3 | Hacked by Michael Tiemann (tiemann@cygnus.com) |
4 | ||
f5adbb8d | 5 | This file is part of GCC. |
8d08fdba | 6 | |
f5adbb8d | 7 | GCC is free software; you can redistribute it and/or modify |
8d08fdba | 8 | it under the terms of the GNU General Public License as published by |
e77f031d | 9 | the Free Software Foundation; either version 3, or (at your option) |
8d08fdba MS |
10 | any later version. |
11 | ||
f5adbb8d | 12 | GCC is distributed in the hope that it will be useful, |
8d08fdba MS |
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 | |
e77f031d NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
8d08fdba MS |
20 | |
21 | ||
3fd5abcf | 22 | /* This file contains the functions for converting C++ expressions |
8d08fdba MS |
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" | |
8d052bc7 | 28 | #include "system.h" |
4977bab6 | 29 | #include "coretypes.h" |
2adfab87 | 30 | #include "target.h" |
2adfab87 | 31 | #include "cp-tree.h" |
d8a2d370 | 32 | #include "stor-layout.h" |
8d08fdba | 33 | #include "flags.h" |
f25a2b52 | 34 | #include "intl.h" |
8d08fdba | 35 | #include "convert.h" |
314e6352 ML |
36 | #include "stringpool.h" |
37 | #include "attribs.h" | |
e92cc029 | 38 | |
4b978f96 | 39 | static tree convert_to_pointer_force (tree, tree, tsubst_flags_t); |
ae00383b | 40 | static tree build_type_conversion (tree, tree); |
4b978f96 | 41 | static tree build_up_reference (tree, tree, int, tree, tsubst_flags_t); |
76545796 | 42 | static void diagnose_ref_binding (location_t, tree, tree, tree); |
49c249e1 | 43 | |
8d08fdba MS |
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: | |
415594bb | 54 | In convert.c, convert_to_integer[_maybe_fold]. |
8d08fdba | 55 | In c-typeck.c, build_binary_op_nodefault (boolean ops), |
0cbd7506 | 56 | and c_common_truthvalue_conversion. |
8d08fdba MS |
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 | ||
8d08fdba MS |
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 | |
6e03b280 | 71 | else try C-style pointer conversion. */ |
e92cc029 | 72 | |
8d08fdba | 73 | static tree |
415594bb JM |
74 | cp_convert_to_pointer (tree type, tree expr, bool dofold, |
75 | tsubst_flags_t complain) | |
8d08fdba | 76 | { |
926ce8bd KH |
77 | tree intype = TREE_TYPE (expr); |
78 | enum tree_code form; | |
31bcaa20 | 79 | tree rval; |
6bdfada4 | 80 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
5a3c9cf2 | 81 | |
0c482362 AP |
82 | if (intype == error_mark_node) |
83 | return error_mark_node; | |
71851aaa | 84 | |
9e1e64ec | 85 | if (MAYBE_CLASS_TYPE_P (intype)) |
e92cc029 | 86 | { |
e92cc029 | 87 | intype = complete_type (intype); |
d0f062fb | 88 | if (!COMPLETE_TYPE_P (intype)) |
e92cc029 | 89 | { |
4b978f96 | 90 | if (complain & tf_error) |
f012c8ef | 91 | error_at (loc, "can%'t convert from incomplete type %qH to %qI", |
4b978f96 | 92 | intype, type); |
e92cc029 MS |
93 | return error_mark_node; |
94 | } | |
95 | ||
7993382e | 96 | rval = build_type_conversion (type, expr); |
e92cc029 MS |
97 | if (rval) |
98 | { | |
4b978f96 PC |
99 | if ((complain & tf_error) |
100 | && rval == error_mark_node) | |
f012c8ef | 101 | error_at (loc, "conversion of %qE from %qH to %qI is ambiguous", |
5a3c9cf2 | 102 | expr, intype, type); |
e92cc029 MS |
103 | return rval; |
104 | } | |
105 | } | |
106 | ||
faf5394a | 107 | /* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */ |
50e10fa8 | 108 | if (TYPE_PTR_P (type) |
9a3b49ac | 109 | && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE |
b72801e2 | 110 | || VOID_TYPE_P (TREE_TYPE (type)))) |
9a3b49ac | 111 | { |
33c25e5c MM |
112 | if (TYPE_PTRMEMFUNC_P (intype) |
113 | || TREE_CODE (intype) == METHOD_TYPE) | |
4b978f96 | 114 | return convert_member_func_to_ptr (type, expr, complain); |
50e10fa8 | 115 | if (TYPE_PTR_P (TREE_TYPE (expr))) |
d6b4ea85 | 116 | return build_nop (type, expr); |
9a3b49ac MS |
117 | intype = TREE_TYPE (expr); |
118 | } | |
119 | ||
c87978aa JM |
120 | if (expr == error_mark_node) |
121 | return error_mark_node; | |
122 | ||
71851aaa MS |
123 | form = TREE_CODE (intype); |
124 | ||
71a93b08 | 125 | if (INDIRECT_TYPE_P (intype)) |
8d08fdba MS |
126 | { |
127 | intype = TYPE_MAIN_VARIANT (intype); | |
128 | ||
129 | if (TYPE_MAIN_VARIANT (type) != intype | |
50e10fa8 | 130 | && TYPE_PTR_P (type) |
8d08fdba | 131 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE |
9e1e64ec PC |
132 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (type)) |
133 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype)) | |
338d90b8 | 134 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
8d08fdba MS |
135 | { |
136 | enum tree_code code = PLUS_EXPR; | |
338d90b8 | 137 | tree binfo; |
7993382e MM |
138 | tree intype_class; |
139 | tree type_class; | |
140 | bool same_p; | |
338d90b8 | 141 | |
7993382e MM |
142 | intype_class = TREE_TYPE (intype); |
143 | type_class = TREE_TYPE (type); | |
144 | ||
c8094d83 | 145 | same_p = same_type_p (TYPE_MAIN_VARIANT (intype_class), |
7993382e MM |
146 | TYPE_MAIN_VARIANT (type_class)); |
147 | binfo = NULL_TREE; | |
00a17e31 | 148 | /* Try derived to base conversion. */ |
7993382e | 149 | if (!same_p) |
22854930 PC |
150 | binfo = lookup_base (intype_class, type_class, ba_check, |
151 | NULL, complain); | |
7993382e | 152 | if (!same_p && !binfo) |
8d08fdba | 153 | { |
00a17e31 | 154 | /* Try base to derived conversion. */ |
22854930 PC |
155 | binfo = lookup_base (type_class, intype_class, ba_check, |
156 | NULL, complain); | |
8d08fdba MS |
157 | code = MINUS_EXPR; |
158 | } | |
338d90b8 NS |
159 | if (binfo == error_mark_node) |
160 | return error_mark_node; | |
7993382e | 161 | if (binfo || same_p) |
8d08fdba | 162 | { |
7993382e | 163 | if (binfo) |
4b978f96 | 164 | expr = build_base_path (code, expr, binfo, 0, complain); |
00a17e31 | 165 | /* Add any qualifier conversions. */ |
7993382e | 166 | return build_nop (type, expr); |
8d08fdba MS |
167 | } |
168 | } | |
8d08fdba | 169 | |
a5ac359a | 170 | if (TYPE_PTRMEMFUNC_P (type)) |
28cbf42c | 171 | { |
4b978f96 | 172 | if (complain & tf_error) |
f012c8ef | 173 | error_at (loc, "cannot convert %qE from type %qH to type %qI", |
4b978f96 | 174 | expr, intype, type); |
a5ac359a MM |
175 | return error_mark_node; |
176 | } | |
b928a651 | 177 | |
a5ac359a MM |
178 | return build_nop (type, expr); |
179 | } | |
66b1156a | 180 | else if ((TYPE_PTRDATAMEM_P (type) && TYPE_PTRDATAMEM_P (intype)) |
6e03b280 OW |
181 | || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) |
182 | return convert_ptrmem (type, expr, /*allow_inverse_p=*/false, | |
4b978f96 | 183 | /*c_cast_p=*/false, complain); |
d8f8dca1 MM |
184 | else if (TYPE_PTRMEMFUNC_P (intype)) |
185 | { | |
d6b4ea85 MM |
186 | if (!warn_pmf2ptr) |
187 | { | |
188 | if (TREE_CODE (expr) == PTRMEM_CST) | |
4b978f96 | 189 | return cp_convert_to_pointer (type, PTRMEM_CST_MEMBER (expr), |
415594bb | 190 | dofold, complain); |
d6b4ea85 MM |
191 | else if (TREE_CODE (expr) == OFFSET_REF) |
192 | { | |
193 | tree object = TREE_OPERAND (expr, 0); | |
194 | return get_member_function_from_ptrfunc (&object, | |
89fcabaf | 195 | TREE_OPERAND (expr, 1), |
4b978f96 | 196 | complain); |
d6b4ea85 MM |
197 | } |
198 | } | |
bc51de9c | 199 | if (complain & tf_error) |
f012c8ef | 200 | error_at (loc, "cannot convert %qE from type %qH to type %qI", |
bc51de9c | 201 | expr, intype, type); |
d8f8dca1 MM |
202 | return error_mark_node; |
203 | } | |
8d08fdba | 204 | |
33c2474d | 205 | if (null_ptr_cst_p (expr)) |
8d08fdba | 206 | { |
d8f8dca1 | 207 | if (TYPE_PTRMEMFUNC_P (type)) |
08e17d9d | 208 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0, |
4b978f96 | 209 | /*c_cast_p=*/false, complain); |
cd8ed629 | 210 | |
f61af651 PC |
211 | if (complain & tf_warning) |
212 | maybe_warn_zero_as_null_pointer_constant (expr, loc); | |
213 | ||
e3692e02 PC |
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); | |
8d08fdba | 222 | } |
66b1156a | 223 | else if (TYPE_PTRMEM_P (type) && INTEGRAL_CODE_P (form)) |
201fbb7f | 224 | { |
4b978f96 | 225 | if (complain & tf_error) |
f012c8ef | 226 | error_at (loc, "invalid conversion from %qH to %qI", intype, type); |
201fbb7f GDR |
227 | return error_mark_node; |
228 | } | |
8d08fdba | 229 | |
2986ae00 | 230 | if (INTEGRAL_CODE_P (form)) |
8d08fdba | 231 | { |
f5963e61 | 232 | if (TYPE_PRECISION (intype) == POINTER_SIZE) |
8d08fdba | 233 | return build1 (CONVERT_EXPR, type, expr); |
4b978f96 PC |
234 | expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr, |
235 | complain); | |
8dc2b103 NS |
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. */ | |
7a504f33 RS |
239 | gcc_assert (GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (TREE_TYPE (expr))) |
240 | == GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type))); | |
c8094d83 | 241 | |
dcbb27dd JM |
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 | ||
415594bb | 247 | return convert_to_pointer_maybe_fold (type, expr, dofold); |
8d08fdba MS |
248 | } |
249 | ||
e6e174e5 | 250 | if (type_unknown_p (expr)) |
4b978f96 | 251 | return instantiate_type (type, expr, complain); |
e6e174e5 | 252 | |
4b978f96 | 253 | if (complain & tf_error) |
f012c8ef | 254 | error_at (loc, "cannot convert %qE from type %qH to type %qI", |
4b978f96 | 255 | expr, intype, type); |
8d08fdba MS |
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). */ | |
e92cc029 | 262 | |
8d08fdba | 263 | static tree |
4b978f96 | 264 | convert_to_pointer_force (tree type, tree expr, tsubst_flags_t complain) |
8d08fdba | 265 | { |
926ce8bd KH |
266 | tree intype = TREE_TYPE (expr); |
267 | enum tree_code form = TREE_CODE (intype); | |
c8094d83 | 268 | |
8d08fdba MS |
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 | |
9e1e64ec PC |
275 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (type)) |
276 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype)) | |
8d08fdba MS |
277 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
278 | { | |
279 | enum tree_code code = PLUS_EXPR; | |
338d90b8 NS |
280 | tree binfo; |
281 | ||
282 | binfo = lookup_base (TREE_TYPE (intype), TREE_TYPE (type), | |
22854930 | 283 | ba_unique, NULL, complain); |
338d90b8 | 284 | if (!binfo) |
8d08fdba | 285 | { |
338d90b8 | 286 | binfo = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), |
22854930 | 287 | ba_unique, NULL, complain); |
338d90b8 | 288 | code = MINUS_EXPR; |
8d08fdba | 289 | } |
338d90b8 NS |
290 | if (binfo == error_mark_node) |
291 | return error_mark_node; | |
292 | if (binfo) | |
8d08fdba | 293 | { |
4b978f96 | 294 | expr = build_base_path (code, expr, binfo, 0, complain); |
0cbd7506 MS |
295 | if (expr == error_mark_node) |
296 | return error_mark_node; | |
00a17e31 | 297 | /* Add any qualifier conversions. */ |
338d90b8 NS |
298 | if (!same_type_p (TREE_TYPE (TREE_TYPE (expr)), |
299 | TREE_TYPE (type))) | |
7993382e | 300 | expr = build_nop (type, expr); |
338d90b8 | 301 | return expr; |
8d08fdba | 302 | } |
8d08fdba | 303 | } |
8d08fdba MS |
304 | } |
305 | ||
415594bb | 306 | return cp_convert_to_pointer (type, expr, /*fold*/false, complain); |
8d08fdba MS |
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. | |
08ac397c JM |
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. */ | |
e92cc029 | 316 | |
8d08fdba | 317 | static tree |
4b978f96 PC |
318 | build_up_reference (tree type, tree arg, int flags, tree decl, |
319 | tsubst_flags_t complain) | |
8d08fdba | 320 | { |
eb66be0e | 321 | tree rval; |
8926095f | 322 | tree argtype = TREE_TYPE (arg); |
8d08fdba | 323 | tree target_type = TREE_TYPE (type); |
8d08fdba | 324 | |
9f613f06 | 325 | gcc_assert (TYPE_REF_P (type)); |
8d08fdba | 326 | |
72b3e203 | 327 | if ((flags & DIRECT_BIND) && ! lvalue_p (arg)) |
8d08fdba | 328 | { |
08ac397c JM |
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. */ | |
eb66be0e | 331 | tree targ = arg; |
08ac397c | 332 | |
efd7ad5c | 333 | arg = make_temporary_var_for_ref_to_temp (decl, target_type); |
8d1e67c6 MM |
334 | |
335 | /* Process the initializer for the declaration. */ | |
9a3b49ac | 336 | DECL_INITIAL (arg) = targ; |
d174af6c | 337 | cp_finish_decl (arg, targ, /*init_const_expr_p=*/false, NULL_TREE, |
c37dc68e | 338 | LOOKUP_ONLYCONVERTING|DIRECT_BIND); |
e349ee73 | 339 | } |
bb19d4af | 340 | else if (!(flags & DIRECT_BIND) && ! obvalue_p (arg)) |
81bd268c | 341 | return get_target_expr_sfinae (arg, complain); |
e349ee73 | 342 | |
08ac397c | 343 | /* If we had a way to wrap this up, and say, if we ever needed its |
d2e5ee5c MS |
344 | address, transform all occurrences of the register, into a memory |
345 | reference we could win better. */ | |
81bd268c | 346 | rval = cp_build_addr_expr (arg, complain); |
162bc98d JM |
347 | if (rval == error_mark_node) |
348 | return error_mark_node; | |
349 | ||
6633d636 MS |
350 | if ((flags & LOOKUP_PROTECT) |
351 | && TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type) | |
9e1e64ec PC |
352 | && MAYBE_CLASS_TYPE_P (argtype) |
353 | && MAYBE_CLASS_TYPE_P (target_type)) | |
6633d636 | 354 | { |
2db1ab2d | 355 | /* We go through lookup_base for the access control. */ |
22854930 PC |
356 | tree binfo = lookup_base (argtype, target_type, ba_check, |
357 | NULL, complain); | |
6633d636 MS |
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); | |
4b978f96 | 362 | rval = build_base_path (PLUS_EXPR, rval, binfo, 1, complain); |
6633d636 | 363 | } |
eb66be0e MS |
364 | else |
365 | rval | |
4b978f96 PC |
366 | = convert_to_pointer_force (build_pointer_type (target_type), |
367 | rval, complain); | |
7993382e | 368 | return build_nop (type, rval); |
8d08fdba MS |
369 | } |
370 | ||
08aead78 NS |
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. | |
c8094d83 | 374 | |
08aead78 NS |
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 | |
76545796 | 380 | diagnose_ref_binding (location_t loc, tree reftype, tree intype, tree decl) |
08aead78 NS |
381 | { |
382 | tree ttl = TREE_TYPE (reftype); | |
c8094d83 | 383 | |
a347241b JM |
384 | if (!TYPE_REF_IS_RVALUE (reftype) |
385 | && !CP_TYPE_CONST_NON_VOLATILE_P (ttl)) | |
08aead78 NS |
386 | { |
387 | const char *msg; | |
388 | ||
389 | if (CP_TYPE_VOLATILE_P (ttl) && decl) | |
f25a2b52 SZ |
390 | msg = G_("initialization of volatile reference type %q#T from " |
391 | "rvalue of type %qT"); | |
08aead78 | 392 | else if (CP_TYPE_VOLATILE_P (ttl)) |
f25a2b52 SZ |
393 | msg = G_("conversion to volatile reference type %q#T " |
394 | "from rvalue of type %qT"); | |
08aead78 | 395 | else if (decl) |
f25a2b52 SZ |
396 | msg = G_("initialization of non-const reference type %q#T from " |
397 | "rvalue of type %qT"); | |
08aead78 | 398 | else |
f25a2b52 SZ |
399 | msg = G_("conversion to non-const reference type %q#T from " |
400 | "rvalue of type %qT"); | |
08aead78 | 401 | |
5a3c9cf2 | 402 | permerror (loc, msg, reftype, intype); |
08aead78 NS |
403 | } |
404 | } | |
405 | ||
8d08fdba MS |
406 | /* For C++: Only need to do one-level references, but cannot |
407 | get tripped up on signed/unsigned differences. | |
408 | ||
a4443a08 MS |
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. */ | |
8d08fdba | 412 | |
8d08fdba | 413 | tree |
b746c5dc | 414 | convert_to_reference (tree reftype, tree expr, int convtype, |
4b978f96 | 415 | int flags, tree decl, tsubst_flags_t complain) |
8d08fdba | 416 | { |
926ce8bd KH |
417 | tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype)); |
418 | tree intype; | |
8d08fdba | 419 | tree rval = NULL_TREE; |
8ccc31eb | 420 | tree rval_as_conversion = NULL_TREE; |
a5ac359a | 421 | bool can_convert_intype_to_type; |
6bdfada4 | 422 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
8ccc31eb | 423 | |
c8094d83 | 424 | if (TREE_CODE (type) == FUNCTION_TYPE |
2303a079 | 425 | && TREE_TYPE (expr) == unknown_type_node) |
b40e334f | 426 | expr = instantiate_type (type, expr, complain); |
a723baf1 MM |
427 | |
428 | if (expr == error_mark_node) | |
429 | return error_mark_node; | |
430 | ||
431 | intype = TREE_TYPE (expr); | |
e6e174e5 | 432 | |
9f613f06 PC |
433 | gcc_assert (!TYPE_REF_P (intype)); |
434 | gcc_assert (TYPE_REF_P (reftype)); | |
8d08fdba | 435 | |
8d08fdba MS |
436 | intype = TYPE_MAIN_VARIANT (intype); |
437 | ||
53db1bc0 | 438 | can_convert_intype_to_type = can_convert_standard (type, intype, complain); |
b40e334f | 439 | |
a5ac359a | 440 | if (!can_convert_intype_to_type |
9e1e64ec | 441 | && (convtype & CONV_IMPLICIT) && MAYBE_CLASS_TYPE_P (intype) |
8ccc31eb MS |
442 | && ! (flags & LOOKUP_NO_CONVERSION)) |
443 | { | |
444 | /* Look for a user-defined conversion to lvalue that we can use. */ | |
445 | ||
277294d7 | 446 | rval_as_conversion |
7993382e | 447 | = build_type_conversion (reftype, expr); |
8ccc31eb MS |
448 | |
449 | if (rval_as_conversion && rval_as_conversion != error_mark_node | |
72b3e203 | 450 | && lvalue_p (rval_as_conversion)) |
8ccc31eb MS |
451 | { |
452 | expr = rval_as_conversion; | |
453 | rval_as_conversion = NULL_TREE; | |
454 | intype = type; | |
a5ac359a | 455 | can_convert_intype_to_type = 1; |
8ccc31eb MS |
456 | } |
457 | } | |
458 | ||
53db1bc0 JM |
459 | if (((convtype & CONV_STATIC) |
460 | && can_convert_standard (intype, type, complain)) | |
a5ac359a | 461 | || ((convtype & CONV_IMPLICIT) && can_convert_intype_to_type)) |
8d08fdba | 462 | { |
4b978f96 PC |
463 | { |
464 | tree ttl = TREE_TYPE (reftype); | |
465 | tree ttr = lvalue_type (expr); | |
8d08fdba | 466 | |
76545796 | 467 | if ((complain & tf_error) |
72b3e203 | 468 | && ! lvalue_p (expr)) |
76545796 | 469 | diagnose_ref_binding (loc, reftype, intype, decl); |
c8094d83 | 470 | |
4b978f96 PC |
471 | if (! (convtype & CONV_CONST) |
472 | && !at_least_as_qualified_p (ttl, ttr)) | |
473 | { | |
474 | if (complain & tf_error) | |
f012c8ef | 475 | permerror (loc, "conversion from %qH to %qI discards qualifiers", |
4b978f96 PC |
476 | ttr, reftype); |
477 | else | |
478 | return error_mark_node; | |
479 | } | |
480 | } | |
8926095f | 481 | |
4b978f96 | 482 | return build_up_reference (reftype, expr, flags, decl, complain); |
8d08fdba | 483 | } |
bb19d4af | 484 | else if ((convtype & CONV_REINTERPRET) && obvalue_p (expr)) |
8926095f MS |
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 | |
a28e3c7f | 488 | by San Diego WP section 5.2.9 paragraph 12, though perhaps it |
8926095f | 489 | should be done directly (jason). (int &)ri ---> *(int*)&ri */ |
a28e3c7f | 490 | |
59be0cdd | 491 | /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they |
0cbd7506 | 492 | meant. */ |
4b978f96 | 493 | if ((complain & tf_warning) |
50e10fa8 | 494 | && TYPE_PTR_P (intype) |
96d84882 PB |
495 | && (comptypes (TREE_TYPE (intype), type, |
496 | COMPARE_BASE | COMPARE_DERIVED))) | |
5a3c9cf2 PC |
497 | warning_at (loc, 0, "casting %qT to %qT does not dereference pointer", |
498 | intype, reftype); | |
c8094d83 | 499 | |
4b978f96 | 500 | rval = cp_build_addr_expr (expr, complain); |
8926095f | 501 | if (rval != error_mark_node) |
3c215895 | 502 | rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), |
4b978f96 | 503 | rval, 0, complain); |
8926095f | 504 | if (rval != error_mark_node) |
7177d104 | 505 | rval = build1 (NOP_EXPR, reftype, rval); |
8926095f | 506 | } |
277294d7 | 507 | else |
faf5394a MS |
508 | { |
509 | rval = convert_for_initialization (NULL_TREE, type, expr, flags, | |
4b978f96 | 510 | ICR_CONVERTING, 0, 0, complain); |
09ad2917 DD |
511 | if (rval == NULL_TREE || rval == error_mark_node) |
512 | return rval; | |
76545796 PC |
513 | if (complain & tf_error) |
514 | diagnose_ref_binding (loc, reftype, intype, decl); | |
4b978f96 | 515 | rval = build_up_reference (reftype, rval, flags, decl, complain); |
faf5394a | 516 | } |
8d08fdba MS |
517 | |
518 | if (rval) | |
519 | { | |
e92cc029 | 520 | /* If we found a way to convert earlier, then use it. */ |
8d08fdba MS |
521 | return rval; |
522 | } | |
523 | ||
4b978f96 | 524 | if (complain & tf_error) |
f012c8ef | 525 | error_at (loc, "cannot convert type %qH to type %qI", intype, reftype); |
878cd289 | 526 | |
8d08fdba MS |
527 | return error_mark_node; |
528 | } | |
529 | ||
530 | /* We are using a reference VAL for its value. Bash that reference all the | |
e92cc029 MS |
531 | way down to its lowest form. */ |
532 | ||
8d08fdba | 533 | tree |
b746c5dc | 534 | convert_from_reference (tree val) |
8d08fdba | 535 | { |
4e3f6d85 | 536 | if (TREE_TYPE (val) |
9f613f06 | 537 | && TYPE_REF_P (TREE_TYPE (val))) |
db24eb1f | 538 | { |
cd41d410 | 539 | tree t = TREE_TYPE (TREE_TYPE (val)); |
db24eb1f | 540 | tree ref = build1 (INDIRECT_REF, t, val); |
c8094d83 | 541 | |
e3ae330d | 542 | mark_exp_read (val); |
db24eb1f NS |
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)); | |
db24eb1f NS |
550 | val = ref; |
551 | } | |
c8094d83 | 552 | |
8d08fdba MS |
553 | return val; |
554 | } | |
f7b9026e JM |
555 | |
556 | /* Really perform an lvalue-to-rvalue conversion, including copying an | |
557 | argument of class type into a temporary. */ | |
558 | ||
559 | tree | |
574cfaa4 | 560 | force_rvalue (tree expr, tsubst_flags_t complain) |
f7b9026e | 561 | { |
574cfaa4 JM |
562 | tree type = TREE_TYPE (expr); |
563 | if (MAYBE_CLASS_TYPE_P (type) && TREE_CODE (expr) != TARGET_EXPR) | |
564 | { | |
9771b263 | 565 | vec<tree, va_gc> *args = make_tree_vector_single (expr); |
574cfaa4 JM |
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 | } | |
f7b9026e | 571 | else |
89fcabaf | 572 | expr = decay_conversion (expr, complain); |
f7b9026e JM |
573 | |
574 | return expr; | |
575 | } | |
9771799c | 576 | |
8d08fdba | 577 | \f |
9e115cec JM |
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 | { | |
dfd7fdca DM |
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)) | |
9e115cec | 591 | { |
dfd7fdca | 592 | gcc_assert (!TREE_OVERFLOW (stripped_orig)); |
9e115cec | 593 | /* Ensure constant sharing. */ |
dfd7fdca DM |
594 | stripped_expr = wide_int_to_tree (TREE_TYPE (stripped_expr), |
595 | wi::to_wide (stripped_expr)); | |
9e115cec | 596 | } |
dfd7fdca DM |
597 | |
598 | return preserve_any_location_wrapper (stripped_expr, expr); | |
9e115cec JM |
599 | } |
600 | ||
601 | /* Fold away simple conversions, but make sure TREE_OVERFLOW is set | |
602 | properly. */ | |
9771799c JM |
603 | |
604 | tree | |
605 | cp_fold_convert (tree type, tree expr) | |
606 | { | |
fb899e32 JM |
607 | tree conv; |
608 | if (TREE_TYPE (expr) == type) | |
609 | conv = expr; | |
d760b068 JM |
610 | else if (TREE_CODE (expr) == PTRMEM_CST |
611 | && same_type_p (TYPE_PTRMEM_CLASS_TYPE (type), | |
612 | PTRMEM_CST_CLASS (expr))) | |
fb899e32 JM |
613 | { |
614 | /* Avoid wrapping a PTRMEM_CST in NOP_EXPR. */ | |
615 | conv = copy_node (expr); | |
616 | TREE_TYPE (conv) = type; | |
617 | } | |
d760b068 JM |
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 | } | |
fb899e32 JM |
624 | else |
625 | { | |
626 | conv = fold_convert (type, expr); | |
627 | conv = ignore_overflows (conv, expr); | |
628 | } | |
9e115cec | 629 | return conv; |
9771799c JM |
630 | } |
631 | ||
37c46b43 MS |
632 | /* C++ conversions, preference to static cast conversions. */ |
633 | ||
634 | tree | |
4b978f96 | 635 | cp_convert (tree type, tree expr, tsubst_flags_t complain) |
37c46b43 | 636 | { |
4b978f96 | 637 | return ocp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL, complain); |
37c46b43 MS |
638 | } |
639 | ||
07231d4f MLI |
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 | |
4b978f96 | 648 | cp_convert_and_check (tree type, tree expr, tsubst_flags_t complain) |
07231d4f MLI |
649 | { |
650 | tree result; | |
651 | ||
652 | if (TREE_TYPE (expr) == type) | |
653 | return expr; | |
cda0a029 JM |
654 | if (expr == error_mark_node) |
655 | return expr; | |
4b978f96 | 656 | result = cp_convert (type, expr, complain); |
07231d4f | 657 | |
4b978f96 | 658 | if ((complain & tf_warning) |
da834cfc JM |
659 | && c_inhibit_evaluation_warnings == 0) |
660 | { | |
cda0a029 JM |
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. */ | |
3212c3c8 | 668 | warning_sentinel w (warn_parentheses); |
144a96e4 | 669 | warning_sentinel c (warn_int_in_bool_context); |
cda0a029 JM |
670 | folded_result = cp_convert (type, folded, tf_none); |
671 | } | |
672 | folded_result = fold_simple (folded_result); | |
673 | if (!TREE_OVERFLOW_P (folded) | |
da834cfc | 674 | && folded_result != error_mark_node) |
6bdfada4 | 675 | warnings_for_convert_and_check (cp_expr_loc_or_loc (expr, input_location), |
e87eed2a | 676 | type, folded, folded_result); |
da834cfc | 677 | } |
07231d4f MLI |
678 | |
679 | return result; | |
680 | } | |
681 | ||
878cd289 MS |
682 | /* Conversion... |
683 | ||
684 | FLAGS indicates how we should behave. */ | |
685 | ||
8d08fdba | 686 | tree |
4b978f96 PC |
687 | ocp_convert (tree type, tree expr, int convtype, int flags, |
688 | tsubst_flags_t complain) | |
8d08fdba | 689 | { |
926ce8bd KH |
690 | tree e = expr; |
691 | enum tree_code code = TREE_CODE (type); | |
4de67c26 | 692 | const char *invalid_conv_diag; |
40449a90 | 693 | tree e1; |
6bdfada4 | 694 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
415594bb | 695 | bool dofold = (convtype & CONV_FOLD); |
8d08fdba | 696 | |
a5ac359a | 697 | if (error_operand_p (e) || type == error_mark_node) |
8d08fdba | 698 | return error_mark_node; |
a4443a08 | 699 | |
5d73aa63 MM |
700 | complete_type (type); |
701 | complete_type (TREE_TYPE (expr)); | |
702 | ||
4de67c26 JM |
703 | if ((invalid_conv_diag |
704 | = targetm.invalid_conversion (TREE_TYPE (expr), type))) | |
705 | { | |
4b978f96 PC |
706 | if (complain & tf_error) |
707 | error (invalid_conv_diag); | |
4de67c26 JM |
708 | return error_mark_node; |
709 | } | |
710 | ||
fa2200cb | 711 | /* FIXME remove when moving to c_fully_fold model. */ |
9783ae5a | 712 | if (!CLASS_TYPE_P (type)) |
82be290b JM |
713 | { |
714 | e = mark_rvalue_use (e); | |
715 | e = scalar_constant_value (e); | |
716 | } | |
88274c4d JM |
717 | if (error_operand_p (e)) |
718 | return error_mark_node; | |
9c0d0367 | 719 | |
39d8c7d2 PC |
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 | ||
36cbfdb0 | 729 | if (MAYBE_CLASS_TYPE_P (type) && (convtype & CONV_FORCE_TEMP)) |
b7558a2c | 730 | /* We need a new temporary; don't take this shortcut. */; |
0fcedd9c | 731 | else if (same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (e))) |
01240200 | 732 | { |
5dab8b11 JM |
733 | tree etype = TREE_TYPE (e); |
734 | if (same_type_p (type, etype)) | |
01240200 MM |
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; | |
34cd5ae7 | 737 | the comparison in fold is just equality of pointers, not a |
96d84882 | 738 | call to comptypes. We don't call fold in this case because |
953360c8 MM |
739 | that can result in infinite recursion; fold will call |
740 | convert, which will call ocp_convert, etc. */ | |
741 | return e; | |
a04678ca | 742 | /* For complex data types, we need to perform componentwise |
0cbd7506 | 743 | conversion. */ |
a04678ca | 744 | else if (TREE_CODE (type) == COMPLEX_TYPE) |
415594bb | 745 | return convert_to_complex_maybe_fold (type, e, dofold); |
b55b02ea | 746 | else if (VECTOR_TYPE_P (type)) |
cda0a029 | 747 | return convert_to_vector (type, e); |
4e8dca1c JM |
748 | else if (TREE_CODE (e) == TARGET_EXPR) |
749 | { | |
750 | /* Don't build a NOP_EXPR of class type. Instead, change the | |
0fcedd9c | 751 | type of the temporary. */ |
5dab8b11 | 752 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, etype)); |
4e8dca1c JM |
753 | TREE_TYPE (e) = TREE_TYPE (TARGET_EXPR_SLOT (e)) = type; |
754 | return e; | |
755 | } | |
5dab8b11 JM |
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 | } | |
01240200 | 762 | else |
8dc2b103 NS |
763 | { |
764 | /* We shouldn't be treating objects of ADDRESSABLE type as | |
765 | rvalues. */ | |
766 | gcc_assert (!TREE_ADDRESSABLE (type)); | |
cda0a029 | 767 | return build_nop (type, e); |
8dc2b103 | 768 | } |
01240200 MM |
769 | } |
770 | ||
40449a90 SL |
771 | e1 = targetm.convert_to_type (type, e); |
772 | if (e1) | |
773 | return e1; | |
774 | ||
a4443a08 | 775 | if (code == VOID_TYPE && (convtype & CONV_STATIC)) |
848b92e1 | 776 | { |
4b978f96 | 777 | e = convert_to_void (e, ICV_CAST, complain); |
66543169 | 778 | return e; |
848b92e1 | 779 | } |
a4443a08 | 780 | |
2986ae00 | 781 | if (INTEGRAL_CODE_P (code)) |
8d08fdba | 782 | { |
f0e01782 | 783 | tree intype = TREE_TYPE (e); |
9e115cec | 784 | tree converted; |
b13e752f MLI |
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) | |
0cbd7506 | 791 | || TREE_CODE (intype) == REAL_TYPE) |
b6ab6892 | 792 | && ! (convtype & CONV_STATIC)) |
50e10fa8 | 793 | || TYPE_PTR_P (intype)) |
b13e752f | 794 | { |
4b978f96 | 795 | if (complain & tf_error) |
5a3c9cf2 | 796 | permerror (loc, "conversion from %q#T to %q#T", intype, type); |
4b978f96 | 797 | else |
b13e752f MLI |
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. */ | |
dfd7fdca | 808 | tree val = fold_for_warn (e); |
4b978f96 | 809 | if ((complain & tf_warning) |
dfd7fdca | 810 | && TREE_CODE (val) == INTEGER_CST |
0ffc4683 | 811 | && ENUM_UNDERLYING_TYPE (type) |
dfd7fdca | 812 | && !int_fits_type_p (val, ENUM_UNDERLYING_TYPE (type))) |
5a3c9cf2 PC |
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); | |
8d08fdba | 817 | } |
9e1e64ec | 818 | if (MAYBE_CLASS_TYPE_P (intype)) |
8d08fdba MS |
819 | { |
820 | tree rval; | |
7993382e | 821 | rval = build_type_conversion (type, e); |
00595019 MS |
822 | if (rval) |
823 | return rval; | |
4b978f96 | 824 | if (complain & tf_error) |
5a3c9cf2 | 825 | error_at (loc, "%q#T used where a %qT was expected", intype, type); |
8d08fdba MS |
826 | return error_mark_node; |
827 | } | |
2986ae00 | 828 | if (code == BOOLEAN_TYPE) |
1ee44b26 | 829 | { |
50e10fa8 | 830 | if (VOID_TYPE_P (intype)) |
5a3c9cf2 | 831 | { |
4b978f96 PC |
832 | if (complain & tf_error) |
833 | error_at (loc, | |
834 | "could not convert %qE from %<void%> to %<bool%>", | |
835 | expr); | |
5a3c9cf2 PC |
836 | return error_mark_node; |
837 | } | |
838 | ||
1ee44b26 JM |
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)) | |
55b13820 | 842 | e = build_nop (ENUM_UNDERLYING_TYPE (intype), e); |
3799a5b8 MP |
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 | } | |
1ee44b26 | 852 | } |
1998463c | 853 | |
415594bb | 854 | converted = convert_to_integer_maybe_fold (type, e, dofold); |
9e115cec JM |
855 | |
856 | /* Ignore any integer overflow caused by the conversion. */ | |
857 | return ignore_overflows (converted, e); | |
8d08fdba | 858 | } |
71a93b08 | 859 | if (INDIRECT_TYPE_P (type) || TYPE_PTRMEM_P (type)) |
415594bb | 860 | return cp_convert_to_pointer (type, e, dofold, complain); |
bb37c4a5 | 861 | if (code == VECTOR_TYPE) |
037cc9c5 FJ |
862 | { |
863 | tree in_vtype = TREE_TYPE (e); | |
9e1e64ec | 864 | if (MAYBE_CLASS_TYPE_P (in_vtype)) |
037cc9c5 FJ |
865 | { |
866 | tree ret_val; | |
867 | ret_val = build_type_conversion (type, e); | |
0cbd7506 MS |
868 | if (ret_val) |
869 | return ret_val; | |
4b978f96 PC |
870 | if (complain & tf_error) |
871 | error_at (loc, "%q#T used where a %qT was expected", | |
872 | in_vtype, type); | |
0cbd7506 | 873 | return error_mark_node; |
037cc9c5 | 874 | } |
cda0a029 | 875 | return convert_to_vector (type, e); |
037cc9c5 | 876 | } |
37c46b43 | 877 | if (code == REAL_TYPE || code == COMPLEX_TYPE) |
8d08fdba | 878 | { |
9e1e64ec | 879 | if (MAYBE_CLASS_TYPE_P (TREE_TYPE (e))) |
8d08fdba MS |
880 | { |
881 | tree rval; | |
7993382e | 882 | rval = build_type_conversion (type, e); |
8d08fdba MS |
883 | if (rval) |
884 | return rval; | |
4b978f96 PC |
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)); | |
8d08fdba | 889 | } |
37c46b43 | 890 | if (code == REAL_TYPE) |
415594bb | 891 | return convert_to_real_maybe_fold (type, e, dofold); |
37c46b43 | 892 | else if (code == COMPLEX_TYPE) |
415594bb | 893 | return convert_to_complex_maybe_fold (type, e, dofold); |
8d08fdba MS |
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. */ | |
9e1e64ec | 899 | if (RECORD_OR_UNION_CODE_P (code)) |
8d08fdba MS |
900 | { |
901 | tree dtype = TREE_TYPE (e); | |
db5ae43f | 902 | tree ctor = NULL_TREE; |
8d08fdba | 903 | |
8d08fdba MS |
904 | dtype = TYPE_MAIN_VARIANT (dtype); |
905 | ||
8d08fdba MS |
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 | ||
277294d7 | 913 | ctor = e; |
faf5394a | 914 | |
81bd268c | 915 | if (abstract_virtuals_error_sfinae (NULL_TREE, type, complain)) |
a7a64a77 | 916 | return error_mark_node; |
59e76fc6 | 917 | |
09357846 | 918 | if (BRACE_ENCLOSED_INITIALIZER_P (ctor)) |
4b978f96 | 919 | ctor = perform_implicit_conversion (type, ctor, complain); |
09357846 JM |
920 | else if ((flags & LOOKUP_ONLYCONVERTING) |
921 | && ! (CLASS_TYPE_P (dtype) && DERIVED_FROM_P (type, dtype))) | |
62c154ed JM |
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]). */ | |
4b978f96 | 925 | ctor = build_user_type_conversion (type, ctor, flags, complain); |
5e818b93 | 926 | else |
c166b898 | 927 | { |
9771b263 | 928 | vec<tree, va_gc> *ctor_vec = make_tree_vector_single (ctor); |
c166b898 ILT |
929 | ctor = build_special_member_call (NULL_TREE, |
930 | complete_ctor_identifier, | |
931 | &ctor_vec, | |
4b978f96 | 932 | type, flags, complain); |
c166b898 ILT |
933 | release_tree_vector (ctor_vec); |
934 | } | |
277294d7 | 935 | if (ctor) |
4b978f96 | 936 | return build_cplus_new (type, ctor, complain); |
8d08fdba MS |
937 | } |
938 | ||
4b978f96 | 939 | if (complain & tf_error) |
111a28c2 DS |
940 | { |
941 | /* If the conversion failed and expr was an invalid use of pointer to | |
942 | member function, try to report a meaningful error. */ | |
d3ea4c06 | 943 | if (invalid_nonstatic_memfn_p (loc, expr, complain)) |
111a28c2 DS |
944 | /* We displayed the error message. */; |
945 | else | |
f012c8ef | 946 | error_at (loc, "conversion from %qH to non-scalar type %qI requested", |
5a3c9cf2 | 947 | TREE_TYPE (expr), type); |
111a28c2 | 948 | } |
8d08fdba MS |
949 | return error_mark_node; |
950 | } | |
951 | ||
babaa9df JM |
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 | ||
b632761d JM |
966 | /* FN is the callee of a CALL_EXPR or AGGR_INIT_EXPR; return the FUNCTION_DECL |
967 | if we can. */ | |
968 | ||
969 | tree | |
f5f035a3 | 970 | cp_get_fndecl_from_callee (tree fn, bool fold /* = true */) |
b632761d JM |
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; | |
71a93b08 | 979 | gcc_assert (INDIRECT_TYPE_P (type)); |
f5f035a3 JM |
980 | if (fold) |
981 | fn = maybe_constant_init (fn); | |
b632761d JM |
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 | ||
f5f035a3 JM |
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 | ||
b632761d JM |
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); | |
6bdfada4 | 1018 | location_t loc = cp_expr_loc_or_loc (call, input_location); |
b632761d JM |
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); | |
71a93b08 | 1026 | if (INDIRECT_TYPE_P (type)) |
b632761d JM |
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 | { | |
097f82ec | 1034 | auto_diagnostic_group d; |
b632761d JM |
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 | { | |
097f82ec | 1043 | auto_diagnostic_group d; |
b632761d JM |
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 | { | |
097f82ec | 1062 | auto_diagnostic_group d; |
b632761d JM |
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 | ||
02cac427 NS |
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 | |
cd0be382 | 1080 | object is, but there is reason to believe that it is the lvalue to rvalue |
02cac427 NS |
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. | |
c8094d83 | 1090 | |
ebeb2c24 SZ |
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. */ | |
02cac427 NS |
1094 | |
1095 | tree | |
ebeb2c24 | 1096 | convert_to_void (tree expr, impl_conv_void implicit, tsubst_flags_t complain) |
02cac427 | 1097 | { |
6bdfada4 | 1098 | location_t loc = cp_expr_loc_or_loc (expr, input_location); |
5a3c9cf2 | 1099 | |
c8094d83 | 1100 | if (expr == error_mark_node |
07c88314 MM |
1101 | || TREE_TYPE (expr) == error_mark_node) |
1102 | return error_mark_node; | |
056928b2 | 1103 | |
38946ea1 JM |
1104 | expr = maybe_undo_parenthesized_ref (expr); |
1105 | ||
84dd815f | 1106 | expr = mark_discarded_use (expr); |
ebeb2c24 | 1107 | if (implicit == ICV_CAST) |
84dd815f | 1108 | /* An explicit cast to void avoids all -Wunused-but-set* warnings. */ |
9fc8dacc | 1109 | mark_exp_read (expr); |
056928b2 | 1110 | |
02cac427 NS |
1111 | if (!TREE_TYPE (expr)) |
1112 | return expr; | |
d3ea4c06 | 1113 | if (invalid_nonstatic_memfn_p (loc, expr, complain)) |
c8b2e872 | 1114 | return error_mark_node; |
9f4faeae MM |
1115 | if (TREE_CODE (expr) == PSEUDO_DTOR_EXPR) |
1116 | { | |
5ade1ed2 | 1117 | if (complain & tf_error) |
5a3c9cf2 | 1118 | error_at (loc, "pseudo-destructor is not called"); |
9f4faeae MM |
1119 | return error_mark_node; |
1120 | } | |
b72801e2 | 1121 | if (VOID_TYPE_P (TREE_TYPE (expr))) |
02cac427 NS |
1122 | return expr; |
1123 | switch (TREE_CODE (expr)) | |
1124 | { | |
1125 | case COND_EXPR: | |
1126 | { | |
0cbd7506 MS |
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); | |
cb8384a3 JM |
1130 | bool side_effects = ((op1 && TREE_SIDE_EFFECTS (op1)) |
1131 | || TREE_SIDE_EFFECTS (op2)); | |
ebeb2c24 | 1132 | tree new_op1, new_op2; |
cb8384a3 | 1133 | new_op1 = NULL_TREE; |
ebeb2c24 SZ |
1134 | if (implicit != ICV_CAST && !side_effects) |
1135 | { | |
cb8384a3 JM |
1136 | if (op1) |
1137 | new_op1 = convert_to_void (op1, ICV_SECOND_OF_COND, complain); | |
ebeb2c24 SZ |
1138 | new_op2 = convert_to_void (op2, ICV_THIRD_OF_COND, complain); |
1139 | } | |
1140 | else | |
1141 | { | |
cb8384a3 JM |
1142 | if (op1) |
1143 | new_op1 = convert_to_void (op1, ICV_CAST, complain); | |
ebeb2c24 SZ |
1144 | new_op2 = convert_to_void (op2, ICV_CAST, complain); |
1145 | } | |
c8094d83 | 1146 | |
cb8384a3 | 1147 | expr = build3 (COND_EXPR, TREE_TYPE (new_op2), |
f293ce4b | 1148 | TREE_OPERAND (expr, 0), new_op1, new_op2); |
0cbd7506 | 1149 | break; |
02cac427 | 1150 | } |
c8094d83 | 1151 | |
02cac427 NS |
1152 | case COMPOUND_EXPR: |
1153 | { | |
0cbd7506 MS |
1154 | /* The second part of a compound expr contains the value. */ |
1155 | tree op1 = TREE_OPERAND (expr,1); | |
ebeb2c24 SZ |
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); | |
c8094d83 | 1161 | |
0cbd7506 | 1162 | if (new_op1 != op1) |
9a52d09b | 1163 | { |
f293ce4b RS |
1164 | tree t = build2 (COMPOUND_EXPR, TREE_TYPE (new_op1), |
1165 | TREE_OPERAND (expr, 0), new_op1); | |
9a52d09b MM |
1166 | expr = t; |
1167 | } | |
1168 | ||
0cbd7506 | 1169 | break; |
02cac427 | 1170 | } |
c8094d83 | 1171 | |
02cac427 NS |
1172 | case NON_LVALUE_EXPR: |
1173 | case NOP_EXPR: | |
00a17e31 | 1174 | /* These have already decayed to rvalue. */ |
02cac427 | 1175 | break; |
c8094d83 | 1176 | |
f4f206f4 | 1177 | case CALL_EXPR: /* We have a special meaning for volatile void fn(). */ |
b632761d | 1178 | maybe_warn_nodiscard (expr, implicit); |
02cac427 | 1179 | break; |
c8094d83 | 1180 | |
02cac427 NS |
1181 | case INDIRECT_REF: |
1182 | { | |
0cbd7506 | 1183 | tree type = TREE_TYPE (expr); |
9f613f06 | 1184 | int is_reference = TYPE_REF_P (TREE_TYPE (TREE_OPERAND (expr, 0))); |
0cbd7506 MS |
1185 | int is_volatile = TYPE_VOLATILE (type); |
1186 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); | |
1187 | ||
bed02d89 | 1188 | /* Can't load the value if we don't know the type. */ |
0cbd7506 | 1189 | if (is_volatile && !is_complete) |
5ade1ed2 DG |
1190 | { |
1191 | if (complain & tf_warning) | |
ebeb2c24 SZ |
1192 | switch (implicit) |
1193 | { | |
1194 | case ICV_CAST: | |
5a3c9cf2 | 1195 | warning_at (loc, 0, "conversion to void will not access " |
ebeb2c24 SZ |
1196 | "object of incomplete type %qT", type); |
1197 | break; | |
1198 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 | 1199 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1200 | "incomplete type %qT in second operand " |
1201 | "of conditional expression", type); | |
1202 | break; | |
1203 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 | 1204 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1205 | "incomplete type %qT in third operand " |
1206 | "of conditional expression", type); | |
1207 | break; | |
1208 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 | 1209 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1210 | "incomplete type %qT in right operand of " |
1211 | "comma operator", type); | |
1212 | break; | |
1213 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 | 1214 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1215 | "incomplete type %qT in left operand of " |
1216 | "comma operator", type); | |
1217 | break; | |
1218 | case ICV_STATEMENT: | |
5a3c9cf2 | 1219 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1220 | "incomplete type %qT in statement", type); |
1221 | break; | |
1222 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 | 1223 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1224 | "incomplete type %qT in for increment " |
1225 | "expression", type); | |
1226 | break; | |
1227 | default: | |
1228 | gcc_unreachable (); | |
1229 | } | |
5ade1ed2 | 1230 | } |
bed02d89 JM |
1231 | /* Don't load the value if this is an implicit dereference, or if |
1232 | the type needs to be handled by ctors/dtors. */ | |
ebeb2c24 | 1233 | else if (is_volatile && is_reference) |
5ade1ed2 DG |
1234 | { |
1235 | if (complain & tf_warning) | |
ebeb2c24 SZ |
1236 | switch (implicit) |
1237 | { | |
1238 | case ICV_CAST: | |
5a3c9cf2 | 1239 | warning_at (loc, 0, "conversion to void will not access " |
ebeb2c24 SZ |
1240 | "object of type %qT", type); |
1241 | break; | |
1242 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 PC |
1243 | warning_at (loc, 0, "implicit dereference will not access " |
1244 | "object of type %qT in second operand of " | |
ebeb2c24 SZ |
1245 | "conditional expression", type); |
1246 | break; | |
1247 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 PC |
1248 | warning_at (loc, 0, "implicit dereference will not access " |
1249 | "object of type %qT in third operand of " | |
ebeb2c24 SZ |
1250 | "conditional expression", type); |
1251 | break; | |
1252 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 PC |
1253 | warning_at (loc, 0, "implicit dereference will not access " |
1254 | "object of type %qT in right operand of " | |
ebeb2c24 SZ |
1255 | "comma operator", type); |
1256 | break; | |
1257 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 PC |
1258 | warning_at (loc, 0, "implicit dereference will not access " |
1259 | "object of type %qT in left operand of comma " | |
1260 | "operator", type); | |
ebeb2c24 SZ |
1261 | break; |
1262 | case ICV_STATEMENT: | |
5a3c9cf2 PC |
1263 | warning_at (loc, 0, "implicit dereference will not access " |
1264 | "object of type %qT in statement", type); | |
ebeb2c24 SZ |
1265 | break; |
1266 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 PC |
1267 | warning_at (loc, 0, "implicit dereference will not access " |
1268 | "object of type %qT in for increment expression", | |
1269 | type); | |
ebeb2c24 SZ |
1270 | break; |
1271 | default: | |
1272 | gcc_unreachable (); | |
1273 | } | |
5ade1ed2 | 1274 | } |
ebeb2c24 SZ |
1275 | else if (is_volatile && TREE_ADDRESSABLE (type)) |
1276 | { | |
1277 | if (complain & tf_warning) | |
1278 | switch (implicit) | |
1279 | { | |
1280 | case ICV_CAST: | |
5a3c9cf2 | 1281 | warning_at (loc, 0, "conversion to void will not access " |
ebeb2c24 | 1282 | "object of non-trivially-copyable type %qT", |
5a3c9cf2 | 1283 | type); |
ebeb2c24 SZ |
1284 | break; |
1285 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 | 1286 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1287 | "non-trivially-copyable type %qT in second " |
1288 | "operand of conditional expression", type); | |
1289 | break; | |
1290 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 | 1291 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1292 | "non-trivially-copyable type %qT in third " |
1293 | "operand of conditional expression", type); | |
1294 | break; | |
1295 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 | 1296 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1297 | "non-trivially-copyable type %qT in right " |
1298 | "operand of comma operator", type); | |
1299 | break; | |
1300 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 | 1301 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1302 | "non-trivially-copyable type %qT in left " |
1303 | "operand of comma operator", type); | |
1304 | break; | |
1305 | case ICV_STATEMENT: | |
5a3c9cf2 | 1306 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 | 1307 | "non-trivially-copyable type %qT in statement", |
5a3c9cf2 | 1308 | type); |
ebeb2c24 SZ |
1309 | break; |
1310 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 | 1311 | warning_at (loc, 0, "indirection will not access object of " |
ebeb2c24 SZ |
1312 | "non-trivially-copyable type %qT in for " |
1313 | "increment expression", type); | |
1314 | break; | |
1315 | default: | |
1316 | gcc_unreachable (); | |
1317 | } | |
1318 | } | |
bed02d89 | 1319 | if (is_reference || !is_volatile || !is_complete || TREE_ADDRESSABLE (type)) |
041d7a27 LCW |
1320 | { |
1321 | /* Emit a warning (if enabled) when the "effect-less" INDIRECT_REF | |
1322 | operation is stripped off. Note that we don't warn about | |
1323 | - an expression with TREE_NO_WARNING set. (For an example of | |
1324 | such expressions, see build_over_call in call.c.) | |
1325 | - automatic dereferencing of references, since the user cannot | |
fd4116f4 | 1326 | control it. (See also warn_if_unused_value() in c-common.c.) */ |
041d7a27 | 1327 | if (warn_unused_value |
ebeb2c24 | 1328 | && implicit != ICV_CAST |
041d7a27 LCW |
1329 | && (complain & tf_warning) |
1330 | && !TREE_NO_WARNING (expr) | |
1331 | && !is_reference) | |
5a3c9cf2 | 1332 | warning_at (loc, OPT_Wunused_value, "value computed is not used"); |
041d7a27 | 1333 | expr = TREE_OPERAND (expr, 0); |
ac853c90 PC |
1334 | if (TREE_CODE (expr) == CALL_EXPR) |
1335 | maybe_warn_nodiscard (expr, implicit); | |
041d7a27 | 1336 | } |
0cbd7506 MS |
1337 | |
1338 | break; | |
02cac427 | 1339 | } |
c8094d83 | 1340 | |
02cac427 NS |
1341 | case VAR_DECL: |
1342 | { | |
0cbd7506 MS |
1343 | /* External variables might be incomplete. */ |
1344 | tree type = TREE_TYPE (expr); | |
1345 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); | |
1346 | ||
5ade1ed2 | 1347 | if (TYPE_VOLATILE (type) && !is_complete && (complain & tf_warning)) |
ebeb2c24 SZ |
1348 | switch (implicit) |
1349 | { | |
1350 | case ICV_CAST: | |
5a3c9cf2 | 1351 | warning_at (loc, 0, "conversion to void will not access " |
ebeb2c24 SZ |
1352 | "object %qE of incomplete type %qT", expr, type); |
1353 | break; | |
1354 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 PC |
1355 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1356 | "not be accessed in second operand of " | |
ebeb2c24 SZ |
1357 | "conditional expression", expr, type); |
1358 | break; | |
1359 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 PC |
1360 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1361 | "not be accessed in third operand of " | |
ebeb2c24 SZ |
1362 | "conditional expression", expr, type); |
1363 | break; | |
1364 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 PC |
1365 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1366 | "not be accessed in right operand of comma operator", | |
1367 | expr, type); | |
ebeb2c24 SZ |
1368 | break; |
1369 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 PC |
1370 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1371 | "not be accessed in left operand of comma operator", | |
1372 | expr, type); | |
ebeb2c24 SZ |
1373 | break; |
1374 | case ICV_STATEMENT: | |
5a3c9cf2 PC |
1375 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1376 | "not be accessed in statement", expr, type); | |
ebeb2c24 SZ |
1377 | break; |
1378 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 PC |
1379 | warning_at (loc, 0, "variable %qE of incomplete type %qT will " |
1380 | "not be accessed in for increment expression", | |
1381 | expr, type); | |
ebeb2c24 SZ |
1382 | break; |
1383 | default: | |
1384 | gcc_unreachable (); | |
1385 | } | |
1386 | ||
0cbd7506 | 1387 | break; |
02cac427 | 1388 | } |
2bdb0643 | 1389 | |
c08cd4c1 JM |
1390 | case TARGET_EXPR: |
1391 | /* Don't bother with the temporary object returned from a function if | |
45177337 JM |
1392 | we don't use it, don't need to destroy it, and won't abort in |
1393 | assign_temp. We'll still | |
c08cd4c1 JM |
1394 | allocate space for it in expand_call or declare_return_variable, |
1395 | but we don't need to track it through all the tree phases. */ | |
5de1a1eb | 1396 | if (TARGET_EXPR_IMPLICIT_P (expr) |
45177337 | 1397 | && !TREE_ADDRESSABLE (TREE_TYPE (expr))) |
c08cd4c1 JM |
1398 | { |
1399 | tree init = TARGET_EXPR_INITIAL (expr); | |
1400 | if (TREE_CODE (init) == AGGR_INIT_EXPR | |
1401 | && !AGGR_INIT_VIA_CTOR_P (init)) | |
1402 | { | |
5039610b | 1403 | tree fn = AGGR_INIT_EXPR_FN (init); |
db3927fb | 1404 | expr = build_call_array_loc (input_location, |
b632761d JM |
1405 | TREE_TYPE (TREE_TYPE |
1406 | (TREE_TYPE (fn))), | |
db3927fb AH |
1407 | fn, |
1408 | aggr_init_expr_nargs (init), | |
1409 | AGGR_INIT_EXPR_ARGP (init)); | |
c08cd4c1 JM |
1410 | } |
1411 | } | |
b632761d | 1412 | maybe_warn_nodiscard (expr, implicit); |
c08cd4c1 JM |
1413 | break; |
1414 | ||
02cac427 NS |
1415 | default:; |
1416 | } | |
46f0d909 | 1417 | expr = resolve_nondeduced_context (expr, complain); |
02cac427 NS |
1418 | { |
1419 | tree probe = expr; | |
c8094d83 | 1420 | |
02cac427 NS |
1421 | if (TREE_CODE (probe) == ADDR_EXPR) |
1422 | probe = TREE_OPERAND (expr, 0); | |
96d6c610 JM |
1423 | if (type_unknown_p (probe)) |
1424 | { | |
1425 | /* [over.over] enumerates the places where we can take the address | |
1426 | of an overloaded function, and this is not one of them. */ | |
5ade1ed2 | 1427 | if (complain & tf_error) |
ebeb2c24 SZ |
1428 | switch (implicit) |
1429 | { | |
1430 | case ICV_CAST: | |
5a3c9cf2 PC |
1431 | error_at (loc, "conversion to void " |
1432 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1433 | break; |
1434 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 PC |
1435 | error_at (loc, "second operand of conditional expression " |
1436 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1437 | break; |
1438 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 PC |
1439 | error_at (loc, "third operand of conditional expression " |
1440 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1441 | break; |
1442 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 PC |
1443 | error_at (loc, "right operand of comma operator " |
1444 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1445 | break; |
1446 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 PC |
1447 | error_at (loc, "left operand of comma operator " |
1448 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1449 | break; |
1450 | case ICV_STATEMENT: | |
5a3c9cf2 PC |
1451 | error_at (loc, "statement " |
1452 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1453 | break; |
1454 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 PC |
1455 | error_at (loc, "for increment expression " |
1456 | "cannot resolve address of overloaded function"); | |
ebeb2c24 SZ |
1457 | break; |
1458 | } | |
5ade1ed2 DG |
1459 | else |
1460 | return error_mark_node; | |
632f2871 | 1461 | expr = void_node; |
96d6c610 | 1462 | } |
ebeb2c24 | 1463 | else if (implicit != ICV_CAST && probe == expr && is_overloaded_fn (probe)) |
05f8c2d5 JM |
1464 | { |
1465 | /* Only warn when there is no &. */ | |
5ade1ed2 | 1466 | if (complain & tf_warning) |
ebeb2c24 SZ |
1467 | switch (implicit) |
1468 | { | |
1469 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 PC |
1470 | warning_at (loc, OPT_Waddress, |
1471 | "second operand of conditional expression " | |
1472 | "is a reference, not call, to function %qE", expr); | |
ebeb2c24 SZ |
1473 | break; |
1474 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 PC |
1475 | warning_at (loc, OPT_Waddress, |
1476 | "third operand of conditional expression " | |
1477 | "is a reference, not call, to function %qE", expr); | |
ebeb2c24 SZ |
1478 | break; |
1479 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 PC |
1480 | warning_at (loc, OPT_Waddress, |
1481 | "right operand of comma operator " | |
1482 | "is a reference, not call, to function %qE", expr); | |
ebeb2c24 SZ |
1483 | break; |
1484 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 PC |
1485 | warning_at (loc, OPT_Waddress, |
1486 | "left operand of comma operator " | |
1487 | "is a reference, not call, to function %qE", expr); | |
ebeb2c24 SZ |
1488 | break; |
1489 | case ICV_STATEMENT: | |
5a3c9cf2 PC |
1490 | warning_at (loc, OPT_Waddress, |
1491 | "statement is a reference, not call, to function %qE", | |
1492 | expr); | |
ebeb2c24 SZ |
1493 | break; |
1494 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 PC |
1495 | warning_at (loc, OPT_Waddress, |
1496 | "for increment expression " | |
1497 | "is a reference, not call, to function %qE", expr); | |
ebeb2c24 SZ |
1498 | break; |
1499 | default: | |
1500 | gcc_unreachable (); | |
1501 | } | |
1502 | ||
05f8c2d5 JM |
1503 | if (TREE_CODE (expr) == COMPONENT_REF) |
1504 | expr = TREE_OPERAND (expr, 0); | |
1505 | } | |
02cac427 | 1506 | } |
c8094d83 | 1507 | |
b72801e2 | 1508 | if (expr != error_mark_node && !VOID_TYPE_P (TREE_TYPE (expr))) |
02cac427 | 1509 | { |
ebeb2c24 | 1510 | if (implicit != ICV_CAST |
55792875 ILT |
1511 | && warn_unused_value |
1512 | && !TREE_NO_WARNING (expr) | |
1513 | && !processing_template_decl) | |
dfb5c523 MM |
1514 | { |
1515 | /* The middle end does not warn about expressions that have | |
1516 | been explicitly cast to void, so we must do so here. */ | |
5ade1ed2 DG |
1517 | if (!TREE_SIDE_EFFECTS (expr)) { |
1518 | if (complain & tf_warning) | |
ebeb2c24 SZ |
1519 | switch (implicit) |
1520 | { | |
1521 | case ICV_SECOND_OF_COND: | |
5a3c9cf2 PC |
1522 | warning_at (loc, OPT_Wunused_value, |
1523 | "second operand of conditional expression " | |
1524 | "has no effect"); | |
ebeb2c24 SZ |
1525 | break; |
1526 | case ICV_THIRD_OF_COND: | |
5a3c9cf2 PC |
1527 | warning_at (loc, OPT_Wunused_value, |
1528 | "third operand of conditional expression " | |
1529 | "has no effect"); | |
ebeb2c24 SZ |
1530 | break; |
1531 | case ICV_RIGHT_OF_COMMA: | |
5a3c9cf2 PC |
1532 | warning_at (loc, OPT_Wunused_value, |
1533 | "right operand of comma operator has no effect"); | |
ebeb2c24 SZ |
1534 | break; |
1535 | case ICV_LEFT_OF_COMMA: | |
5a3c9cf2 PC |
1536 | warning_at (loc, OPT_Wunused_value, |
1537 | "left operand of comma operator has no effect"); | |
ebeb2c24 SZ |
1538 | break; |
1539 | case ICV_STATEMENT: | |
5a3c9cf2 PC |
1540 | warning_at (loc, OPT_Wunused_value, |
1541 | "statement has no effect"); | |
ebeb2c24 SZ |
1542 | break; |
1543 | case ICV_THIRD_IN_FOR: | |
5a3c9cf2 PC |
1544 | warning_at (loc, OPT_Wunused_value, |
1545 | "for increment expression has no effect"); | |
ebeb2c24 SZ |
1546 | break; |
1547 | default: | |
1548 | gcc_unreachable (); | |
1549 | } | |
5ade1ed2 | 1550 | } |
c8094d83 MS |
1551 | else |
1552 | { | |
dfb5c523 MM |
1553 | tree e; |
1554 | enum tree_code code; | |
be93747e | 1555 | enum tree_code_class tclass; |
c8094d83 | 1556 | |
dfb5c523 MM |
1557 | e = expr; |
1558 | /* We might like to warn about (say) "(int) f()", as the | |
1559 | cast has no effect, but the compiler itself will | |
1560 | generate implicit conversions under some | |
cc29fd59 | 1561 | circumstances. (For example a block copy will be |
dfb5c523 MM |
1562 | turned into a call to "__builtin_memcpy", with a |
1563 | conversion of the return value to an appropriate | |
1564 | type.) So, to avoid false positives, we strip | |
d9fa1233 MM |
1565 | conversions. Do not use STRIP_NOPs because it will |
1566 | not strip conversions to "void", as that is not a | |
1567 | mode-preserving conversion. */ | |
1568 | while (TREE_CODE (e) == NOP_EXPR) | |
1569 | e = TREE_OPERAND (e, 0); | |
dfb5c523 MM |
1570 | |
1571 | code = TREE_CODE (e); | |
be93747e KG |
1572 | tclass = TREE_CODE_CLASS (code); |
1573 | if ((tclass == tcc_comparison | |
1574 | || tclass == tcc_unary | |
1575 | || (tclass == tcc_binary | |
dfb5c523 MM |
1576 | && !(code == MODIFY_EXPR |
1577 | || code == INIT_EXPR | |
1578 | || code == PREDECREMENT_EXPR | |
1579 | || code == PREINCREMENT_EXPR | |
1580 | || code == POSTDECREMENT_EXPR | |
5c67ba02 MG |
1581 | || code == POSTINCREMENT_EXPR)) |
1582 | || code == VEC_PERM_EXPR | |
1583 | || code == VEC_COND_EXPR) | |
5ade1ed2 | 1584 | && (complain & tf_warning)) |
5a3c9cf2 | 1585 | warning_at (loc, OPT_Wunused_value, "value computed is not used"); |
dfb5c523 MM |
1586 | } |
1587 | } | |
e895113a | 1588 | expr = build1 (CONVERT_EXPR, void_type_node, expr); |
02cac427 | 1589 | } |
ccbe00a4 | 1590 | if (! TREE_SIDE_EFFECTS (expr)) |
632f2871 | 1591 | expr = void_node; |
02cac427 NS |
1592 | return expr; |
1593 | } | |
1594 | ||
a4443a08 MS |
1595 | /* Create an expression whose value is that of EXPR, |
1596 | converted to type TYPE. The TREE_TYPE of the value | |
1597 | is always TYPE. This function implements all reasonable | |
1598 | conversions; callers should filter out those that are | |
37c46b43 MS |
1599 | not permitted by the language being compiled. |
1600 | ||
1601 | Most of this routine is from build_reinterpret_cast. | |
1602 | ||
3b426391 | 1603 | The back end cannot call cp_convert (what was convert) because |
37c46b43 MS |
1604 | conversions to/from basetypes may involve memory references |
1605 | (vbases) and adding or subtracting small values (multiple | |
1606 | inheritance), but it calls convert from the constant folding code | |
7dfa399d | 1607 | on subtrees of already built trees after it has ripped them apart. |
37c46b43 MS |
1608 | |
1609 | Also, if we ever support range variables, we'll probably also have to | |
1610 | do a little bit more work. */ | |
a4443a08 MS |
1611 | |
1612 | tree | |
b746c5dc | 1613 | convert (tree type, tree expr) |
a4443a08 | 1614 | { |
37c46b43 MS |
1615 | tree intype; |
1616 | ||
1617 | if (type == error_mark_node || expr == error_mark_node) | |
1618 | return error_mark_node; | |
1619 | ||
37c46b43 MS |
1620 | intype = TREE_TYPE (expr); |
1621 | ||
71a93b08 | 1622 | if (INDIRECT_TYPE_P (type) && INDIRECT_TYPE_P (intype)) |
cda0a029 | 1623 | return build_nop (type, expr); |
37c46b43 | 1624 | |
415594bb | 1625 | return ocp_convert (type, expr, CONV_BACKEND_CONVERT, |
4b978f96 PC |
1626 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION, |
1627 | tf_warning_or_error); | |
a4443a08 MS |
1628 | } |
1629 | ||
37c46b43 | 1630 | /* Like cp_convert, except permit conversions to take place which |
8d08fdba MS |
1631 | are not normally allowed due to access restrictions |
1632 | (such as conversion from sub-type to private super-type). */ | |
e92cc029 | 1633 | |
8d08fdba | 1634 | tree |
4b978f96 | 1635 | convert_force (tree type, tree expr, int convtype, tsubst_flags_t complain) |
8d08fdba | 1636 | { |
926ce8bd KH |
1637 | tree e = expr; |
1638 | enum tree_code code = TREE_CODE (type); | |
8d08fdba MS |
1639 | |
1640 | if (code == REFERENCE_TYPE) | |
cda0a029 JM |
1641 | return convert_to_reference (type, e, CONV_C_CAST, 0, |
1642 | NULL_TREE, complain); | |
8d08fdba MS |
1643 | |
1644 | if (code == POINTER_TYPE) | |
cda0a029 | 1645 | return convert_to_pointer_force (type, e, complain); |
8d08fdba | 1646 | |
51c184be | 1647 | /* From typeck.c convert_for_assignment */ |
50e10fa8 | 1648 | if (((TYPE_PTR_P (TREE_TYPE (e)) && TREE_CODE (e) == ADDR_EXPR |
8d08fdba | 1649 | && TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE) |
51c184be MS |
1650 | || integer_zerop (e) |
1651 | || TYPE_PTRMEMFUNC_P (TREE_TYPE (e))) | |
8d08fdba | 1652 | && TYPE_PTRMEMFUNC_P (type)) |
08e17d9d MM |
1653 | /* compatible pointer to member functions. */ |
1654 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1, | |
4b978f96 | 1655 | /*c_cast_p=*/1, complain); |
6060a796 | 1656 | |
4b978f96 | 1657 | return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL, complain); |
8d08fdba MS |
1658 | } |
1659 | ||
8d08fdba MS |
1660 | /* Convert an aggregate EXPR to type XTYPE. If a conversion |
1661 | exists, return the attempted conversion. This may | |
1662 | return ERROR_MARK_NODE if the conversion is not | |
1663 | allowed (references private members, etc). | |
1664 | If no conversion exists, NULL_TREE is returned. | |
1665 | ||
f30432d7 MS |
1666 | FIXME: Ambiguity checking is wrong. Should choose one by the implicit |
1667 | object parameter, or by the second standard conversion sequence if | |
1668 | that doesn't do it. This will probably wait for an overloading rewrite. | |
1669 | (jason 8/9/95) */ | |
8d08fdba | 1670 | |
ae00383b | 1671 | static tree |
7993382e | 1672 | build_type_conversion (tree xtype, tree expr) |
8d08fdba MS |
1673 | { |
1674 | /* C++: check to see if we can convert this aggregate type | |
e1cd6e56 | 1675 | into the required type. */ |
b40e334f PC |
1676 | return build_user_type_conversion (xtype, expr, LOOKUP_NORMAL, |
1677 | tf_warning_or_error); | |
8d08fdba MS |
1678 | } |
1679 | ||
b7484fbe MS |
1680 | /* Convert the given EXPR to one of a group of types suitable for use in an |
1681 | expression. DESIRES is a combination of various WANT_* flags (q.v.) | |
b746c5dc | 1682 | which indicates which types are suitable. If COMPLAIN is true, complain |
b7484fbe | 1683 | about ambiguity; otherwise, the caller will deal with it. */ |
8d08fdba | 1684 | |
b7484fbe | 1685 | tree |
b746c5dc | 1686 | build_expr_type_conversion (int desires, tree expr, bool complain) |
8d08fdba | 1687 | { |
b7484fbe | 1688 | tree basetype = TREE_TYPE (expr); |
b370501f | 1689 | tree conv = NULL_TREE; |
02020185 | 1690 | tree winner = NULL_TREE; |
8d08fdba | 1691 | |
9a004410 | 1692 | if (null_node_p (expr) |
c8094d83 | 1693 | && (desires & WANT_INT) |
03d0f4af | 1694 | && !(desires & WANT_NULL)) |
70dc395a | 1695 | { |
620e594b | 1696 | location_t loc = |
70dc395a DS |
1697 | expansion_point_location_if_in_system_header (input_location); |
1698 | ||
1699 | warning_at (loc, OPT_Wconversion_null, | |
1700 | "converting NULL to non-pointer type"); | |
1701 | } | |
c8094d83 | 1702 | |
07c88314 MM |
1703 | if (basetype == error_mark_node) |
1704 | return error_mark_node; | |
1705 | ||
9e1e64ec | 1706 | if (! MAYBE_CLASS_TYPE_P (basetype)) |
02020185 JM |
1707 | switch (TREE_CODE (basetype)) |
1708 | { | |
1709 | case INTEGER_TYPE: | |
03d0f4af | 1710 | if ((desires & WANT_NULL) && null_ptr_cst_p (expr)) |
02020185 | 1711 | return expr; |
191816a3 | 1712 | /* fall through. */ |
02020185 JM |
1713 | |
1714 | case BOOLEAN_TYPE: | |
1715 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1716 | case ENUMERAL_TYPE: | |
1717 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1718 | case REAL_TYPE: | |
1719 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1720 | case POINTER_TYPE: | |
1721 | return (desires & WANT_POINTER) ? expr : NULL_TREE; | |
c8094d83 | 1722 | |
02020185 JM |
1723 | case FUNCTION_TYPE: |
1724 | case ARRAY_TYPE: | |
89fcabaf PC |
1725 | return (desires & WANT_POINTER) ? decay_conversion (expr, |
1726 | tf_warning_or_error) | |
0cbd7506 | 1727 | : NULL_TREE; |
4576ceaf | 1728 | |
1ff6b2c8 | 1729 | case COMPLEX_TYPE: |
4576ceaf | 1730 | case VECTOR_TYPE: |
1ff6b2c8 | 1731 | if ((desires & WANT_VECTOR_OR_COMPLEX) == 0) |
4576ceaf JJ |
1732 | return NULL_TREE; |
1733 | switch (TREE_CODE (TREE_TYPE (basetype))) | |
1734 | { | |
1735 | case INTEGER_TYPE: | |
1736 | case BOOLEAN_TYPE: | |
1737 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1738 | case ENUMERAL_TYPE: | |
1739 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1740 | case REAL_TYPE: | |
1741 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1742 | default: | |
1743 | return NULL_TREE; | |
1744 | } | |
1745 | ||
02020185 JM |
1746 | default: |
1747 | return NULL_TREE; | |
1748 | } | |
1749 | ||
1750 | /* The code for conversions from class type is currently only used for | |
1751 | delete expressions. Other expressions are handled by build_new_op. */ | |
309714d4 | 1752 | if (!complete_type_or_maybe_complain (basetype, expr, complain)) |
29f4ceab GB |
1753 | return error_mark_node; |
1754 | if (!TYPE_HAS_CONVERSION (basetype)) | |
02020185 JM |
1755 | return NULL_TREE; |
1756 | ||
9c7d5cae | 1757 | for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv)) |
02020185 JM |
1758 | { |
1759 | int win = 0; | |
1760 | tree candidate; | |
1761 | tree cand = TREE_VALUE (conv); | |
848bf88d | 1762 | cand = OVL_FIRST (cand); |
02020185 JM |
1763 | |
1764 | if (winner && winner == cand) | |
1765 | continue; | |
1766 | ||
e57d93c6 JM |
1767 | if (DECL_NONCONVERTING_P (cand)) |
1768 | continue; | |
1769 | ||
ee76b931 | 1770 | candidate = non_reference (TREE_TYPE (TREE_TYPE (cand))); |
02020185 JM |
1771 | |
1772 | switch (TREE_CODE (candidate)) | |
1773 | { | |
1774 | case BOOLEAN_TYPE: | |
1775 | case INTEGER_TYPE: | |
1776 | win = (desires & WANT_INT); break; | |
1777 | case ENUMERAL_TYPE: | |
1778 | win = (desires & WANT_ENUM); break; | |
1779 | case REAL_TYPE: | |
1780 | win = (desires & WANT_FLOAT); break; | |
1781 | case POINTER_TYPE: | |
1782 | win = (desires & WANT_POINTER); break; | |
1783 | ||
1ff6b2c8 | 1784 | case COMPLEX_TYPE: |
4576ceaf | 1785 | case VECTOR_TYPE: |
1ff6b2c8 | 1786 | if ((desires & WANT_VECTOR_OR_COMPLEX) == 0) |
4576ceaf JJ |
1787 | break; |
1788 | switch (TREE_CODE (TREE_TYPE (candidate))) | |
1789 | { | |
1790 | case BOOLEAN_TYPE: | |
1791 | case INTEGER_TYPE: | |
1792 | win = (desires & WANT_INT); break; | |
1793 | case ENUMERAL_TYPE: | |
1794 | win = (desires & WANT_ENUM); break; | |
1795 | case REAL_TYPE: | |
1796 | win = (desires & WANT_FLOAT); break; | |
1797 | default: | |
1798 | break; | |
1799 | } | |
1800 | break; | |
1801 | ||
02020185 | 1802 | default: |
c5918c21 JM |
1803 | /* A wildcard could be instantiated to match any desired |
1804 | type, but we can't deduce the template argument. */ | |
1805 | if (WILDCARD_TYPE_P (candidate)) | |
1806 | win = true; | |
02020185 JM |
1807 | break; |
1808 | } | |
1809 | ||
1810 | if (win) | |
1811 | { | |
c5918c21 JM |
1812 | if (TREE_CODE (cand) == TEMPLATE_DECL) |
1813 | { | |
1814 | if (complain) | |
1815 | error ("default type conversion can't deduce template" | |
1816 | " argument for %qD", cand); | |
1817 | return error_mark_node; | |
1818 | } | |
1819 | ||
02020185 JM |
1820 | if (winner) |
1821 | { | |
ca45eca1 JM |
1822 | tree winner_type |
1823 | = non_reference (TREE_TYPE (TREE_TYPE (winner))); | |
1824 | ||
1825 | if (!same_type_ignoring_top_level_qualifiers_p (winner_type, | |
1826 | candidate)) | |
02020185 | 1827 | { |
ca45eca1 JM |
1828 | if (complain) |
1829 | { | |
1830 | error ("ambiguous default type conversion from %qT", | |
1831 | basetype); | |
2d45625f PC |
1832 | inform (input_location, |
1833 | " candidate conversions include %qD and %qD", | |
1834 | winner, cand); | |
ca45eca1 JM |
1835 | } |
1836 | return error_mark_node; | |
02020185 | 1837 | } |
02020185 | 1838 | } |
ca45eca1 JM |
1839 | |
1840 | winner = cand; | |
02020185 JM |
1841 | } |
1842 | } | |
b7484fbe | 1843 | |
02020185 JM |
1844 | if (winner) |
1845 | { | |
ee76b931 | 1846 | tree type = non_reference (TREE_TYPE (TREE_TYPE (winner))); |
b40e334f PC |
1847 | return build_user_type_conversion (type, expr, LOOKUP_NORMAL, |
1848 | tf_warning_or_error); | |
8d08fdba | 1849 | } |
b7484fbe | 1850 | |
3c215895 | 1851 | return NULL_TREE; |
8d08fdba | 1852 | } |
39211cd5 | 1853 | |
e92cc029 MS |
1854 | /* Implements integral promotion (4.1) and float->double promotion. */ |
1855 | ||
39211cd5 | 1856 | tree |
b746c5dc | 1857 | type_promotes_to (tree type) |
39211cd5 | 1858 | { |
40449a90 SL |
1859 | tree promoted_type; |
1860 | ||
f30432d7 MS |
1861 | if (type == error_mark_node) |
1862 | return error_mark_node; | |
1863 | ||
39211cd5 | 1864 | type = TYPE_MAIN_VARIANT (type); |
2986ae00 | 1865 | |
40449a90 SL |
1866 | /* Check for promotions of target-defined types first. */ |
1867 | promoted_type = targetm.promoted_type (type); | |
1868 | if (promoted_type) | |
1869 | return promoted_type; | |
1870 | ||
2986ae00 MS |
1871 | /* bool always promotes to int (not unsigned), even if it's the same |
1872 | size. */ | |
66be89f0 | 1873 | if (TREE_CODE (type) == BOOLEAN_TYPE) |
2986ae00 MS |
1874 | type = integer_type_node; |
1875 | ||
1876 | /* Normally convert enums to int, but convert wide enums to something | |
62984918 JM |
1877 | wider. Scoped enums don't promote, but pretend they do for backward |
1878 | ABI bug compatibility wrt varargs. */ | |
2986ae00 | 1879 | else if (TREE_CODE (type) == ENUMERAL_TYPE |
b6baa67d KVH |
1880 | || type == char16_type_node |
1881 | || type == char32_type_node | |
2986ae00 | 1882 | || type == wchar_type_node) |
cf2ac46f | 1883 | { |
eab01c18 MK |
1884 | tree prom = type; |
1885 | ||
1886 | if (TREE_CODE (type) == ENUMERAL_TYPE) | |
1887 | { | |
1888 | prom = ENUM_UNDERLYING_TYPE (prom); | |
1889 | if (!ENUM_IS_SCOPED (type) | |
1890 | && ENUM_FIXED_UNDERLYING_TYPE_P (type)) | |
1891 | { | |
1892 | /* ISO C++17, 7.6/4. A prvalue of an unscoped enumeration type | |
1893 | whose underlying type is fixed (10.2) can be converted to a | |
1894 | prvalue of its underlying type. Moreover, if integral promotion | |
1895 | can be applied to its underlying type, a prvalue of an unscoped | |
1896 | enumeration type whose underlying type is fixed can also be | |
1897 | converted to a prvalue of the promoted underlying type. */ | |
1898 | return type_promotes_to (prom); | |
1899 | } | |
1900 | } | |
1901 | ||
cf2ac46f JM |
1902 | int precision = MAX (TYPE_PRECISION (type), |
1903 | TYPE_PRECISION (integer_type_node)); | |
b0c48229 | 1904 | tree totype = c_common_type_for_size (precision, 0); |
62984918 JM |
1905 | if (TYPE_UNSIGNED (prom) |
1906 | && ! int_fits_type_p (TYPE_MAX_VALUE (prom), totype)) | |
1907 | prom = c_common_type_for_size (precision, 1); | |
1908 | else | |
1909 | prom = totype; | |
967444bb | 1910 | if (SCOPED_ENUM_P (type)) |
62984918 JM |
1911 | { |
1912 | if (abi_version_crosses (6) | |
1913 | && TYPE_MODE (prom) != TYPE_MODE (type)) | |
1914 | warning (OPT_Wabi, "scoped enum %qT passed through ... as " | |
1915 | "%qT before -fabi-version=6, %qT after", | |
1916 | type, prom, ENUM_UNDERLYING_TYPE (type)); | |
1917 | if (!abi_version_at_least (6)) | |
1918 | type = prom; | |
1919 | } | |
cf2ac46f | 1920 | else |
62984918 | 1921 | type = prom; |
cf2ac46f | 1922 | } |
d72040f5 | 1923 | else if (c_promoting_integer_type_p (type)) |
39211cd5 | 1924 | { |
3d4683cb | 1925 | /* Retain unsignedness if really not getting bigger. */ |
8df83eae | 1926 | if (TYPE_UNSIGNED (type) |
3d4683cb | 1927 | && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) |
39211cd5 MS |
1928 | type = unsigned_type_node; |
1929 | else | |
1930 | type = integer_type_node; | |
1931 | } | |
1932 | else if (type == float_type_node) | |
1933 | type = double_type_node; | |
c8094d83 | 1934 | |
0a72704b | 1935 | return type; |
39211cd5 | 1936 | } |
75650646 | 1937 | |
75650646 MM |
1938 | /* The routines below this point are carefully written to conform to |
1939 | the standard. They use the same terminology, and follow the rules | |
1940 | closely. Although they are used only in pt.c at the moment, they | |
1941 | should presumably be used everywhere in the future. */ | |
1942 | ||
8b8b203a JM |
1943 | /* True iff EXPR can be converted to TYPE via a qualification conversion. |
1944 | Callers should check for identical types before calling this function. */ | |
1945 | ||
1946 | bool | |
1947 | can_convert_qual (tree type, tree expr) | |
1948 | { | |
1949 | tree expr_type = TREE_TYPE (expr); | |
1950 | gcc_assert (!same_type_p (type, expr_type)); | |
1951 | ||
1952 | if (TYPE_PTR_P (type) && TYPE_PTR_P (expr_type)) | |
1953 | return comp_ptr_ttypes (TREE_TYPE (type), TREE_TYPE (expr_type)); | |
1954 | else if (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (expr_type)) | |
1955 | return (same_type_p (TYPE_PTRMEM_CLASS_TYPE (type), | |
1956 | TYPE_PTRMEM_CLASS_TYPE (expr_type)) | |
1957 | && comp_ptr_ttypes (TYPE_PTRMEM_POINTED_TO_TYPE (type), | |
1958 | TYPE_PTRMEM_POINTED_TO_TYPE (expr_type))); | |
1959 | else | |
1960 | return false; | |
1961 | } | |
1962 | ||
e1467ff2 MM |
1963 | /* Attempt to perform qualification conversions on EXPR to convert it |
1964 | to TYPE. Return the resulting expression, or error_mark_node if | |
c5f50290 JM |
1965 | the conversion was impossible. Since this is only used by |
1966 | convert_nontype_argument, we fold the conversion. */ | |
e1467ff2 | 1967 | |
c8094d83 | 1968 | tree |
b746c5dc | 1969 | perform_qualification_conversions (tree type, tree expr) |
75650646 | 1970 | { |
a5ac359a MM |
1971 | tree expr_type; |
1972 | ||
1973 | expr_type = TREE_TYPE (expr); | |
1974 | ||
6f25cb35 MM |
1975 | if (same_type_p (type, expr_type)) |
1976 | return expr; | |
8b8b203a | 1977 | else if (can_convert_qual (type, expr)) |
c5f50290 | 1978 | return cp_fold_convert (type, expr); |
e1467ff2 MM |
1979 | else |
1980 | return error_mark_node; | |
75650646 | 1981 | } |
b8fd7909 JM |
1982 | |
1983 | /* True iff T is a transaction-safe function type. */ | |
1984 | ||
1985 | bool | |
1986 | tx_safe_fn_type_p (tree t) | |
1987 | { | |
1988 | if (TREE_CODE (t) != FUNCTION_TYPE | |
1989 | && TREE_CODE (t) != METHOD_TYPE) | |
1990 | return false; | |
1991 | return !!lookup_attribute ("transaction_safe", TYPE_ATTRIBUTES (t)); | |
1992 | } | |
1993 | ||
1994 | /* Return the transaction-unsafe variant of transaction-safe function type | |
1995 | T. */ | |
1996 | ||
1997 | tree | |
1998 | tx_unsafe_fn_variant (tree t) | |
1999 | { | |
2000 | gcc_assert (tx_safe_fn_type_p (t)); | |
2001 | tree attrs = remove_attribute ("transaction_safe", | |
2002 | TYPE_ATTRIBUTES (t)); | |
2003 | return cp_build_type_attribute_variant (t, attrs); | |
2004 | } | |
2005 | ||
2006 | /* Return true iff FROM can convert to TO by a transaction-safety | |
2007 | conversion. */ | |
2008 | ||
51dc6603 | 2009 | static bool |
b8fd7909 JM |
2010 | can_convert_tx_safety (tree to, tree from) |
2011 | { | |
2012 | return (flag_tm && tx_safe_fn_type_p (from) | |
2013 | && same_type_p (to, tx_unsafe_fn_variant (from))); | |
2014 | } | |
51dc6603 JM |
2015 | |
2016 | /* Return true iff FROM can convert to TO by dropping noexcept. */ | |
2017 | ||
2018 | static bool | |
2019 | noexcept_conv_p (tree to, tree from) | |
2020 | { | |
2021 | if (!flag_noexcept_type) | |
2022 | return false; | |
2023 | ||
2024 | tree t = non_reference (to); | |
2025 | tree f = from; | |
2026 | if (TYPE_PTRMEMFUNC_P (t) | |
2027 | && TYPE_PTRMEMFUNC_P (f)) | |
2028 | { | |
2029 | t = TYPE_PTRMEMFUNC_FN_TYPE (t); | |
2030 | f = TYPE_PTRMEMFUNC_FN_TYPE (f); | |
2031 | } | |
9f613f06 PC |
2032 | if (TYPE_PTR_P (t) |
2033 | && TYPE_PTR_P (f)) | |
51dc6603 JM |
2034 | { |
2035 | t = TREE_TYPE (t); | |
2036 | f = TREE_TYPE (f); | |
2037 | } | |
2038 | tree_code code = TREE_CODE (f); | |
2039 | if (TREE_CODE (t) != code) | |
2040 | return false; | |
2041 | if (code != FUNCTION_TYPE && code != METHOD_TYPE) | |
2042 | return false; | |
2043 | if (!type_throw_all_p (t) | |
2044 | || type_throw_all_p (f)) | |
2045 | return false; | |
2046 | tree v = build_exception_variant (f, NULL_TREE); | |
2047 | return same_type_p (t, v); | |
2048 | } | |
2049 | ||
2050 | /* Return true iff FROM can convert to TO by a function pointer conversion. */ | |
2051 | ||
2052 | bool | |
2053 | fnptr_conv_p (tree to, tree from) | |
2054 | { | |
2055 | tree t = non_reference (to); | |
2056 | tree f = from; | |
2057 | if (TYPE_PTRMEMFUNC_P (t) | |
2058 | && TYPE_PTRMEMFUNC_P (f)) | |
2059 | { | |
2060 | t = TYPE_PTRMEMFUNC_FN_TYPE (t); | |
2061 | f = TYPE_PTRMEMFUNC_FN_TYPE (f); | |
2062 | } | |
9f613f06 PC |
2063 | if (TYPE_PTR_P (t) |
2064 | && TYPE_PTR_P (f)) | |
51dc6603 JM |
2065 | { |
2066 | t = TREE_TYPE (t); | |
2067 | f = TREE_TYPE (f); | |
2068 | } | |
2069 | ||
2070 | return (noexcept_conv_p (t, f) | |
2071 | || can_convert_tx_safety (t, f)); | |
2072 | } | |
2073 | ||
e6d7d618 JM |
2074 | /* Return FN with any NOP_EXPRs stripped that represent function pointer |
2075 | conversions or conversions to the same type. */ | |
51dc6603 JM |
2076 | |
2077 | tree | |
2078 | strip_fnptr_conv (tree fn) | |
2079 | { | |
2080 | while (TREE_CODE (fn) == NOP_EXPR) | |
2081 | { | |
2082 | tree op = TREE_OPERAND (fn, 0); | |
e6d7d618 JM |
2083 | tree ft = TREE_TYPE (fn); |
2084 | tree ot = TREE_TYPE (op); | |
2085 | if (same_type_p (ft, ot) | |
2086 | || fnptr_conv_p (ft, ot)) | |
51dc6603 JM |
2087 | fn = op; |
2088 | else | |
2089 | break; | |
2090 | } | |
2091 | return fn; | |
2092 | } |