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471086d6 | 1 | /* Language-level data type conversion for GNU C++. |
107c7f39 | 2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
b2af2a93 | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
aa139c3f | 4 | Free Software Foundation, Inc. |
471086d6 | 5 | Hacked by Michael Tiemann (tiemann@cygnus.com) |
6 | ||
6f0d25a6 | 7 | This file is part of GCC. |
471086d6 | 8 | |
6f0d25a6 | 9 | GCC is free software; you can redistribute it and/or modify |
471086d6 | 10 | it under the terms of the GNU General Public License as published by |
aa139c3f | 11 | the Free Software Foundation; either version 3, or (at your option) |
471086d6 | 12 | any later version. |
13 | ||
6f0d25a6 | 14 | GCC is distributed in the hope that it will be useful, |
471086d6 | 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
aa139c3f | 20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
471086d6 | 22 | |
23 | ||
af86cc06 | 24 | /* This file contains the functions for converting C++ expressions |
471086d6 | 25 | to different data types. The only entry point is `convert'. |
26 | Every language front end must have a `convert' function | |
27 | but what kind of conversions it does will depend on the language. */ | |
28 | ||
29 | #include "config.h" | |
b3ef7553 | 30 | #include "system.h" |
805e22b2 | 31 | #include "coretypes.h" |
32 | #include "tm.h" | |
471086d6 | 33 | #include "tree.h" |
34 | #include "flags.h" | |
35 | #include "cp-tree.h" | |
ca82e026 | 36 | #include "intl.h" |
471086d6 | 37 | #include "convert.h" |
2e8226f7 | 38 | #include "decl.h" |
7a979707 | 39 | #include "target.h" |
96624a9e | 40 | |
e5ead12a | 41 | static tree cp_convert_to_pointer (tree, tree); |
35771a9a | 42 | static tree convert_to_pointer_force (tree, tree); |
ef9571e5 | 43 | static tree build_type_conversion (tree, tree); |
35771a9a | 44 | static tree build_up_reference (tree, tree, int, tree); |
45 | static void warn_ref_binding (tree, tree, tree); | |
71ccdfff | 46 | |
471086d6 | 47 | /* Change of width--truncation and extension of integers or reals-- |
48 | is represented with NOP_EXPR. Proper functioning of many things | |
49 | assumes that no other conversions can be NOP_EXPRs. | |
50 | ||
51 | Conversion between integer and pointer is represented with CONVERT_EXPR. | |
52 | Converting integer to real uses FLOAT_EXPR | |
53 | and real to integer uses FIX_TRUNC_EXPR. | |
54 | ||
55 | Here is a list of all the functions that assume that widening and | |
56 | narrowing is always done with a NOP_EXPR: | |
57 | In convert.c, convert_to_integer. | |
58 | In c-typeck.c, build_binary_op_nodefault (boolean ops), | |
653e5405 | 59 | and c_common_truthvalue_conversion. |
471086d6 | 60 | In expr.c: expand_expr, for operands of a MULT_EXPR. |
61 | In fold-const.c: fold. | |
62 | In tree.c: get_narrower and get_unwidened. | |
63 | ||
64 | C++: in multiple-inheritance, converting between pointers may involve | |
65 | adjusting them by a delta stored within the class definition. */ | |
66 | \f | |
67 | /* Subroutines of `convert'. */ | |
68 | ||
471086d6 | 69 | /* if converting pointer to pointer |
70 | if dealing with classes, check for derived->base or vice versa | |
71 | else if dealing with method pointers, delegate | |
72 | else convert blindly | |
73 | else if converting class, pass off to build_type_conversion | |
e5ead12a | 74 | else try C-style pointer conversion. */ |
96624a9e | 75 | |
471086d6 | 76 | static tree |
e5ead12a | 77 | cp_convert_to_pointer (tree type, tree expr) |
471086d6 | 78 | { |
cd16867a | 79 | tree intype = TREE_TYPE (expr); |
80 | enum tree_code form; | |
f82eeb87 | 81 | tree rval; |
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 | { |
bf776685 | 90 | error ("can%'t convert from incomplete type %qT to %qT", |
653e5405 | 91 | intype, type); |
96624a9e | 92 | return error_mark_node; |
93 | } | |
94 | ||
8999978b | 95 | rval = build_type_conversion (type, expr); |
96624a9e | 96 | if (rval) |
97 | { | |
98 | if (rval == error_mark_node) | |
0a25aad6 | 99 | error ("conversion of %qE from %qT to %qT is ambiguous", |
653e5405 | 100 | expr, intype, type); |
96624a9e | 101 | return rval; |
102 | } | |
103 | } | |
104 | ||
860740a7 | 105 | /* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */ |
38281c46 | 106 | if (TREE_CODE (type) == POINTER_TYPE |
107 | && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE | |
e3cfe3ce | 108 | || VOID_TYPE_P (TREE_TYPE (type)))) |
38281c46 | 109 | { |
6ab399e8 | 110 | if (TYPE_PTRMEMFUNC_P (intype) |
111 | || TREE_CODE (intype) == METHOD_TYPE) | |
112 | return convert_member_func_to_ptr (type, expr); | |
a63bc44c | 113 | if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE) |
114 | return build_nop (type, expr); | |
38281c46 | 115 | intype = TREE_TYPE (expr); |
116 | } | |
117 | ||
311e42bc | 118 | if (expr == error_mark_node) |
119 | return error_mark_node; | |
120 | ||
74002e1d | 121 | form = TREE_CODE (intype); |
122 | ||
2b77484d | 123 | if (POINTER_TYPE_P (intype)) |
471086d6 | 124 | { |
125 | intype = TYPE_MAIN_VARIANT (intype); | |
126 | ||
127 | if (TYPE_MAIN_VARIANT (type) != intype | |
2b77484d | 128 | && TREE_CODE (type) == POINTER_TYPE |
471086d6 | 129 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE |
95397ff9 | 130 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (type)) |
131 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype)) | |
4a2680fc | 132 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
471086d6 | 133 | { |
134 | enum tree_code code = PLUS_EXPR; | |
4a2680fc | 135 | tree binfo; |
8999978b | 136 | tree intype_class; |
137 | tree type_class; | |
138 | bool same_p; | |
4a2680fc | 139 | |
8999978b | 140 | intype_class = TREE_TYPE (intype); |
141 | type_class = TREE_TYPE (type); | |
142 | ||
9031d10b | 143 | same_p = same_type_p (TYPE_MAIN_VARIANT (intype_class), |
8999978b | 144 | TYPE_MAIN_VARIANT (type_class)); |
145 | binfo = NULL_TREE; | |
c0af329c | 146 | /* Try derived to base conversion. */ |
8999978b | 147 | if (!same_p) |
148 | binfo = lookup_base (intype_class, type_class, ba_check, NULL); | |
149 | if (!same_p && !binfo) | |
471086d6 | 150 | { |
c0af329c | 151 | /* Try base to derived conversion. */ |
8999978b | 152 | binfo = lookup_base (type_class, intype_class, ba_check, NULL); |
471086d6 | 153 | code = MINUS_EXPR; |
154 | } | |
4a2680fc | 155 | if (binfo == error_mark_node) |
156 | return error_mark_node; | |
8999978b | 157 | if (binfo || same_p) |
471086d6 | 158 | { |
8999978b | 159 | if (binfo) |
160 | expr = build_base_path (code, expr, binfo, 0); | |
c0af329c | 161 | /* Add any qualifier conversions. */ |
8999978b | 162 | return build_nop (type, expr); |
471086d6 | 163 | } |
164 | } | |
471086d6 | 165 | |
1bc16cab | 166 | if (TYPE_PTRMEMFUNC_P (type)) |
bea7d742 | 167 | { |
0a25aad6 | 168 | error ("cannot convert %qE from type %qT to type %qT", |
653e5405 | 169 | expr, intype, type); |
1bc16cab | 170 | return error_mark_node; |
171 | } | |
a17aefa2 | 172 | |
1bc16cab | 173 | return build_nop (type, expr); |
174 | } | |
e5ead12a | 175 | else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)) |
176 | || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) | |
177 | return convert_ptrmem (type, expr, /*allow_inverse_p=*/false, | |
85132186 | 178 | /*c_cast_p=*/false, tf_warning_or_error); |
2b77484d | 179 | else if (TYPE_PTRMEMFUNC_P (intype)) |
180 | { | |
a63bc44c | 181 | if (!warn_pmf2ptr) |
182 | { | |
183 | if (TREE_CODE (expr) == PTRMEM_CST) | |
184 | return cp_convert_to_pointer (type, | |
e5ead12a | 185 | PTRMEM_CST_MEMBER (expr)); |
a63bc44c | 186 | else if (TREE_CODE (expr) == OFFSET_REF) |
187 | { | |
188 | tree object = TREE_OPERAND (expr, 0); | |
189 | return get_member_function_from_ptrfunc (&object, | |
190 | TREE_OPERAND (expr, 1)); | |
191 | } | |
192 | } | |
0a25aad6 | 193 | error ("cannot convert %qE from type %qT to type %qT", |
653e5405 | 194 | expr, intype, type); |
2b77484d | 195 | return error_mark_node; |
196 | } | |
471086d6 | 197 | |
ef434176 | 198 | if (null_ptr_cst_p (expr)) |
471086d6 | 199 | { |
2b77484d | 200 | if (TYPE_PTRMEMFUNC_P (type)) |
cb02169c | 201 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0, |
85132186 | 202 | /*c_cast_p=*/false, tf_warning_or_error); |
ad63a0fc | 203 | |
606b494c | 204 | if (TYPE_PTRMEM_P (type)) |
7c446c95 | 205 | { |
206 | /* A NULL pointer-to-member is represented by -1, not by | |
207 | zero. */ | |
697bbc3f | 208 | expr = build_int_cst_type (type, -1); |
7c446c95 | 209 | } |
ad63a0fc | 210 | else |
7016c612 | 211 | expr = build_int_cst (type, 0); |
9031d10b | 212 | |
471086d6 | 213 | return expr; |
214 | } | |
1bc16cab | 215 | else if (TYPE_PTR_TO_MEMBER_P (type) && INTEGRAL_CODE_P (form)) |
de1f960a | 216 | { |
0a25aad6 | 217 | error ("invalid conversion from %qT to %qT", intype, type); |
de1f960a | 218 | return error_mark_node; |
219 | } | |
471086d6 | 220 | |
bb0726a1 | 221 | if (INTEGRAL_CODE_P (form)) |
471086d6 | 222 | { |
c5aa1e92 | 223 | if (TYPE_PRECISION (intype) == POINTER_SIZE) |
471086d6 | 224 | return build1 (CONVERT_EXPR, type, expr); |
771d21fa | 225 | expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr); |
092b1d6f | 226 | /* Modes may be different but sizes should be the same. There |
227 | is supposed to be some integral type that is the same width | |
228 | as a pointer. */ | |
229 | gcc_assert (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))) | |
230 | == GET_MODE_SIZE (TYPE_MODE (type))); | |
9031d10b | 231 | |
471086d6 | 232 | return convert_to_pointer (type, expr); |
233 | } | |
234 | ||
cc4d0855 | 235 | if (type_unknown_p (expr)) |
0fbca5e8 | 236 | return instantiate_type (type, expr, tf_warning_or_error); |
cc4d0855 | 237 | |
0a25aad6 | 238 | error ("cannot convert %qE from type %qT to type %qT", |
653e5405 | 239 | expr, intype, type); |
471086d6 | 240 | return error_mark_node; |
241 | } | |
242 | ||
243 | /* Like convert, except permit conversions to take place which | |
244 | are not normally allowed due to access restrictions | |
245 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 246 | |
471086d6 | 247 | static tree |
35771a9a | 248 | convert_to_pointer_force (tree type, tree expr) |
471086d6 | 249 | { |
cd16867a | 250 | tree intype = TREE_TYPE (expr); |
251 | enum tree_code form = TREE_CODE (intype); | |
9031d10b | 252 | |
471086d6 | 253 | if (form == POINTER_TYPE) |
254 | { | |
255 | intype = TYPE_MAIN_VARIANT (intype); | |
256 | ||
257 | if (TYPE_MAIN_VARIANT (type) != intype | |
258 | && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE | |
95397ff9 | 259 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (type)) |
260 | && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype)) | |
471086d6 | 261 | && TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE) |
262 | { | |
263 | enum tree_code code = PLUS_EXPR; | |
4a2680fc | 264 | tree binfo; |
265 | ||
266 | binfo = lookup_base (TREE_TYPE (intype), TREE_TYPE (type), | |
ada40935 | 267 | ba_unique, NULL); |
4a2680fc | 268 | if (!binfo) |
471086d6 | 269 | { |
4a2680fc | 270 | binfo = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), |
ada40935 | 271 | ba_unique, NULL); |
4a2680fc | 272 | code = MINUS_EXPR; |
471086d6 | 273 | } |
4a2680fc | 274 | if (binfo == error_mark_node) |
275 | return error_mark_node; | |
276 | if (binfo) | |
471086d6 | 277 | { |
4a2680fc | 278 | expr = build_base_path (code, expr, binfo, 0); |
653e5405 | 279 | if (expr == error_mark_node) |
280 | return error_mark_node; | |
c0af329c | 281 | /* Add any qualifier conversions. */ |
4a2680fc | 282 | if (!same_type_p (TREE_TYPE (TREE_TYPE (expr)), |
283 | TREE_TYPE (type))) | |
8999978b | 284 | expr = build_nop (type, expr); |
4a2680fc | 285 | return expr; |
471086d6 | 286 | } |
471086d6 | 287 | } |
471086d6 | 288 | } |
289 | ||
e5ead12a | 290 | return cp_convert_to_pointer (type, expr); |
471086d6 | 291 | } |
292 | ||
293 | /* We are passing something to a function which requires a reference. | |
294 | The type we are interested in is in TYPE. The initial | |
295 | value we have to begin with is in ARG. | |
296 | ||
297 | FLAGS controls how we manage access checking. | |
ca106ab1 | 298 | DIRECT_BIND in FLAGS controls how any temporaries are generated. |
299 | If DIRECT_BIND is set, DECL is the reference we're binding to. */ | |
96624a9e | 300 | |
471086d6 | 301 | static tree |
35771a9a | 302 | build_up_reference (tree type, tree arg, int flags, tree decl) |
471086d6 | 303 | { |
c76251c1 | 304 | tree rval; |
0543e7a9 | 305 | tree argtype = TREE_TYPE (arg); |
471086d6 | 306 | tree target_type = TREE_TYPE (type); |
471086d6 | 307 | |
b4df430b | 308 | gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); |
471086d6 | 309 | |
c76251c1 | 310 | if ((flags & DIRECT_BIND) && ! real_lvalue_p (arg)) |
471086d6 | 311 | { |
ca106ab1 | 312 | /* Create a new temporary variable. We can't just use a TARGET_EXPR |
313 | here because it needs to live as long as DECL. */ | |
c76251c1 | 314 | tree targ = arg; |
ca106ab1 | 315 | |
5ab1aaca | 316 | arg = make_temporary_var_for_ref_to_temp (decl, target_type); |
c23ebfdd | 317 | |
318 | /* Process the initializer for the declaration. */ | |
38281c46 | 319 | DECL_INITIAL (arg) = targ; |
d91303a6 | 320 | cp_finish_decl (arg, targ, /*init_const_expr_p=*/false, NULL_TREE, |
011310f7 | 321 | LOOKUP_ONLYCONVERTING|DIRECT_BIND); |
1ad432f2 | 322 | } |
c76251c1 | 323 | else if (!(flags & DIRECT_BIND) && ! lvalue_p (arg)) |
1d8e4310 | 324 | return get_target_expr (arg); |
1ad432f2 | 325 | |
ca106ab1 | 326 | /* If we had a way to wrap this up, and say, if we ever needed its |
b0df6589 | 327 | address, transform all occurrences of the register, into a memory |
328 | reference we could win better. */ | |
d6fbd579 | 329 | rval = cp_build_addr_expr (arg, tf_warning_or_error); |
15e55420 | 330 | if (rval == error_mark_node) |
331 | return error_mark_node; | |
332 | ||
6686e84d | 333 | if ((flags & LOOKUP_PROTECT) |
334 | && TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type) | |
95397ff9 | 335 | && MAYBE_CLASS_TYPE_P (argtype) |
336 | && MAYBE_CLASS_TYPE_P (target_type)) | |
6686e84d | 337 | { |
7e6960e0 | 338 | /* We go through lookup_base for the access control. */ |
4a2680fc | 339 | tree binfo = lookup_base (argtype, target_type, ba_check, NULL); |
6686e84d | 340 | if (binfo == error_mark_node) |
341 | return error_mark_node; | |
342 | if (binfo == NULL_TREE) | |
343 | return error_not_base_type (target_type, argtype); | |
4a2680fc | 344 | rval = build_base_path (PLUS_EXPR, rval, binfo, 1); |
6686e84d | 345 | } |
c76251c1 | 346 | else |
347 | rval | |
348 | = convert_to_pointer_force (build_pointer_type (target_type), rval); | |
8999978b | 349 | return build_nop (type, rval); |
471086d6 | 350 | } |
351 | ||
519ba62c | 352 | /* Subroutine of convert_to_reference. REFTYPE is the target reference type. |
353 | INTYPE is the original rvalue type and DECL is an optional _DECL node | |
354 | for diagnostics. | |
9031d10b | 355 | |
519ba62c | 356 | [dcl.init.ref] says that if an rvalue is used to |
357 | initialize a reference, then the reference must be to a | |
358 | non-volatile const type. */ | |
359 | ||
360 | static void | |
35771a9a | 361 | warn_ref_binding (tree reftype, tree intype, tree decl) |
519ba62c | 362 | { |
363 | tree ttl = TREE_TYPE (reftype); | |
9031d10b | 364 | |
519ba62c | 365 | if (!CP_TYPE_CONST_NON_VOLATILE_P (ttl)) |
366 | { | |
367 | const char *msg; | |
368 | ||
369 | if (CP_TYPE_VOLATILE_P (ttl) && decl) | |
ca82e026 | 370 | msg = G_("initialization of volatile reference type %q#T from " |
371 | "rvalue of type %qT"); | |
519ba62c | 372 | else if (CP_TYPE_VOLATILE_P (ttl)) |
ca82e026 | 373 | msg = G_("conversion to volatile reference type %q#T " |
374 | "from rvalue of type %qT"); | |
519ba62c | 375 | else if (decl) |
ca82e026 | 376 | msg = G_("initialization of non-const reference type %q#T from " |
377 | "rvalue of type %qT"); | |
519ba62c | 378 | else |
ca82e026 | 379 | msg = G_("conversion to non-const reference type %q#T from " |
380 | "rvalue of type %qT"); | |
519ba62c | 381 | |
2b9e3597 | 382 | permerror (input_location, msg, reftype, intype); |
519ba62c | 383 | } |
384 | } | |
385 | ||
471086d6 | 386 | /* For C++: Only need to do one-level references, but cannot |
387 | get tripped up on signed/unsigned differences. | |
388 | ||
d81e00a4 | 389 | DECL is either NULL_TREE or the _DECL node for a reference that is being |
390 | initialized. It can be error_mark_node if we don't know the _DECL but | |
391 | we know it's an initialization. */ | |
471086d6 | 392 | |
471086d6 | 393 | tree |
35771a9a | 394 | convert_to_reference (tree reftype, tree expr, int convtype, |
653e5405 | 395 | int flags, tree decl) |
471086d6 | 396 | { |
cd16867a | 397 | tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype)); |
398 | tree intype; | |
471086d6 | 399 | tree rval = NULL_TREE; |
1a3f833b | 400 | tree rval_as_conversion = NULL_TREE; |
1bc16cab | 401 | bool can_convert_intype_to_type; |
1a3f833b | 402 | |
9031d10b | 403 | if (TREE_CODE (type) == FUNCTION_TYPE |
d32df6a6 | 404 | && TREE_TYPE (expr) == unknown_type_node) |
9031d10b | 405 | expr = instantiate_type (type, expr, |
0a3b29ad | 406 | (flags & LOOKUP_COMPLAIN) |
0fbca5e8 | 407 | ? tf_warning_or_error : tf_none); |
0a3b29ad | 408 | |
409 | if (expr == error_mark_node) | |
410 | return error_mark_node; | |
411 | ||
412 | intype = TREE_TYPE (expr); | |
cc4d0855 | 413 | |
b4df430b | 414 | gcc_assert (TREE_CODE (intype) != REFERENCE_TYPE); |
ab12ed55 | 415 | gcc_assert (TREE_CODE (reftype) == REFERENCE_TYPE); |
471086d6 | 416 | |
471086d6 | 417 | intype = TYPE_MAIN_VARIANT (intype); |
418 | ||
1bc16cab | 419 | can_convert_intype_to_type = can_convert (type, intype); |
420 | if (!can_convert_intype_to_type | |
95397ff9 | 421 | && (convtype & CONV_IMPLICIT) && MAYBE_CLASS_TYPE_P (intype) |
1a3f833b | 422 | && ! (flags & LOOKUP_NO_CONVERSION)) |
423 | { | |
424 | /* Look for a user-defined conversion to lvalue that we can use. */ | |
425 | ||
0a4be248 | 426 | rval_as_conversion |
8999978b | 427 | = build_type_conversion (reftype, expr); |
1a3f833b | 428 | |
429 | if (rval_as_conversion && rval_as_conversion != error_mark_node | |
430 | && real_lvalue_p (rval_as_conversion)) | |
431 | { | |
432 | expr = rval_as_conversion; | |
433 | rval_as_conversion = NULL_TREE; | |
434 | intype = type; | |
1bc16cab | 435 | can_convert_intype_to_type = 1; |
1a3f833b | 436 | } |
437 | } | |
438 | ||
1bc16cab | 439 | if (((convtype & CONV_STATIC) && can_convert (intype, type)) |
440 | || ((convtype & CONV_IMPLICIT) && can_convert_intype_to_type)) | |
471086d6 | 441 | { |
471086d6 | 442 | if (flags & LOOKUP_COMPLAIN) |
443 | { | |
bc3887cf | 444 | tree ttl = TREE_TYPE (reftype); |
cb0ba4ec | 445 | tree ttr = lvalue_type (expr); |
471086d6 | 446 | |
519ba62c | 447 | if (! real_lvalue_p (expr)) |
448 | warn_ref_binding (reftype, intype, decl); | |
9031d10b | 449 | |
519ba62c | 450 | if (! (convtype & CONV_CONST) |
3e04bd45 | 451 | && !at_least_as_qualified_p (ttl, ttr)) |
2b9e3597 | 452 | permerror (input_location, "conversion from %qT to %qT discards qualifiers", |
07317e69 | 453 | ttr, reftype); |
0543e7a9 | 454 | } |
455 | ||
ca106ab1 | 456 | return build_up_reference (reftype, expr, flags, decl); |
471086d6 | 457 | } |
c07b1ad1 | 458 | else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr)) |
0543e7a9 | 459 | { |
460 | /* When casting an lvalue to a reference type, just convert into | |
461 | a pointer to the new type and deference it. This is allowed | |
e581f478 | 462 | by San Diego WP section 5.2.9 paragraph 12, though perhaps it |
0543e7a9 | 463 | should be done directly (jason). (int &)ri ---> *(int*)&ri */ |
e581f478 | 464 | |
3748625f | 465 | /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they |
653e5405 | 466 | meant. */ |
1a3f833b | 467 | if (TREE_CODE (intype) == POINTER_TYPE |
a09db423 | 468 | && (comptypes (TREE_TYPE (intype), type, |
469 | COMPARE_BASE | COMPARE_DERIVED))) | |
c3ceba8e | 470 | warning (0, "casting %qT to %qT does not dereference pointer", |
00952d10 | 471 | intype, reftype); |
9031d10b | 472 | |
d6fbd579 | 473 | rval = cp_build_addr_expr (expr, tf_warning_or_error); |
0543e7a9 | 474 | if (rval != error_mark_node) |
985e9ee0 | 475 | rval = convert_force (build_pointer_type (TREE_TYPE (reftype)), |
476 | rval, 0); | |
0543e7a9 | 477 | if (rval != error_mark_node) |
b0722fac | 478 | rval = build1 (NOP_EXPR, reftype, rval); |
0543e7a9 | 479 | } |
0a4be248 | 480 | else |
860740a7 | 481 | { |
482 | rval = convert_for_initialization (NULL_TREE, type, expr, flags, | |
183407ee | 483 | ICR_CONVERTING, 0, 0, |
ebd21de4 | 484 | tf_warning_or_error); |
a66fe4cb | 485 | if (rval == NULL_TREE || rval == error_mark_node) |
486 | return rval; | |
519ba62c | 487 | warn_ref_binding (reftype, intype, decl); |
ca106ab1 | 488 | rval = build_up_reference (reftype, rval, flags, decl); |
860740a7 | 489 | } |
471086d6 | 490 | |
491 | if (rval) | |
492 | { | |
96624a9e | 493 | /* If we found a way to convert earlier, then use it. */ |
471086d6 | 494 | return rval; |
495 | } | |
496 | ||
b248d3f7 | 497 | if (flags & LOOKUP_COMPLAIN) |
0a25aad6 | 498 | error ("cannot convert type %qT to type %qT", intype, reftype); |
b248d3f7 | 499 | |
471086d6 | 500 | return error_mark_node; |
501 | } | |
502 | ||
503 | /* We are using a reference VAL for its value. Bash that reference all the | |
96624a9e | 504 | way down to its lowest form. */ |
505 | ||
471086d6 | 506 | tree |
35771a9a | 507 | convert_from_reference (tree val) |
471086d6 | 508 | { |
73bdcca2 | 509 | if (TREE_TYPE (val) |
510 | && TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE) | |
729f89ff | 511 | { |
2fb61329 | 512 | tree t = TREE_TYPE (TREE_TYPE (val)); |
729f89ff | 513 | tree ref = build1 (INDIRECT_REF, t, val); |
9031d10b | 514 | |
3d37a176 | 515 | mark_exp_read (val); |
729f89ff | 516 | /* We *must* set TREE_READONLY when dereferencing a pointer to const, |
517 | so that we get the proper error message if the result is used | |
518 | to assign to. Also, &* is supposed to be a no-op. */ | |
519 | TREE_READONLY (ref) = CP_TYPE_CONST_P (t); | |
520 | TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t); | |
521 | TREE_SIDE_EFFECTS (ref) | |
522 | = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val)); | |
523 | REFERENCE_REF_P (ref) = 1; | |
524 | val = ref; | |
525 | } | |
9031d10b | 526 | |
471086d6 | 527 | return val; |
528 | } | |
e5dab226 | 529 | |
530 | /* Really perform an lvalue-to-rvalue conversion, including copying an | |
531 | argument of class type into a temporary. */ | |
532 | ||
533 | tree | |
534 | force_rvalue (tree expr) | |
535 | { | |
95397ff9 | 536 | if (MAYBE_CLASS_TYPE_P (TREE_TYPE (expr)) && TREE_CODE (expr) != TARGET_EXPR) |
e5dab226 | 537 | expr = ocp_convert (TREE_TYPE (expr), expr, |
538 | CONV_IMPLICIT|CONV_FORCE_TEMP, LOOKUP_NORMAL); | |
539 | else | |
540 | expr = decay_conversion (expr); | |
541 | ||
542 | return expr; | |
543 | } | |
f5220369 | 544 | |
471086d6 | 545 | \f |
a1f05651 | 546 | /* If EXPR and ORIG are INTEGER_CSTs, return a version of EXPR that has |
547 | TREE_OVERFLOW set only if it is set in ORIG. Otherwise, return EXPR | |
548 | unchanged. */ | |
549 | ||
550 | static tree | |
551 | ignore_overflows (tree expr, tree orig) | |
552 | { | |
553 | if (TREE_CODE (expr) == INTEGER_CST | |
554 | && TREE_CODE (orig) == INTEGER_CST | |
555 | && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)) | |
556 | { | |
557 | gcc_assert (!TREE_OVERFLOW (orig)); | |
558 | /* Ensure constant sharing. */ | |
559 | expr = build_int_cst_wide (TREE_TYPE (expr), | |
560 | TREE_INT_CST_LOW (expr), | |
561 | TREE_INT_CST_HIGH (expr)); | |
562 | } | |
563 | return expr; | |
564 | } | |
565 | ||
566 | /* Fold away simple conversions, but make sure TREE_OVERFLOW is set | |
567 | properly. */ | |
f5220369 | 568 | |
569 | tree | |
570 | cp_fold_convert (tree type, tree expr) | |
571 | { | |
a1f05651 | 572 | tree conv = fold_convert (type, expr); |
573 | conv = ignore_overflows (conv, expr); | |
574 | return conv; | |
f5220369 | 575 | } |
576 | ||
c4a8ac95 | 577 | /* C++ conversions, preference to static cast conversions. */ |
578 | ||
579 | tree | |
35771a9a | 580 | cp_convert (tree type, tree expr) |
c4a8ac95 | 581 | { |
582 | return ocp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL); | |
583 | } | |
584 | ||
59dd8856 | 585 | /* C++ equivalent of convert_and_check but using cp_convert as the |
586 | conversion function. | |
587 | ||
588 | Convert EXPR to TYPE, warning about conversion problems with constants. | |
589 | Invoke this function on every expression that is converted implicitly, | |
590 | i.e. because of language rules and not because of an explicit cast. */ | |
591 | ||
592 | tree | |
593 | cp_convert_and_check (tree type, tree expr) | |
594 | { | |
595 | tree result; | |
596 | ||
597 | if (TREE_TYPE (expr) == type) | |
598 | return expr; | |
599 | ||
600 | result = cp_convert (type, expr); | |
601 | ||
48d94ede | 602 | if (c_inhibit_evaluation_warnings == 0 |
603 | && !TREE_OVERFLOW_P (expr) | |
604 | && result != error_mark_node) | |
59dd8856 | 605 | warnings_for_convert_and_check (type, expr, result); |
606 | ||
607 | return result; | |
608 | } | |
609 | ||
b248d3f7 | 610 | /* Conversion... |
611 | ||
612 | FLAGS indicates how we should behave. */ | |
613 | ||
471086d6 | 614 | tree |
35771a9a | 615 | ocp_convert (tree type, tree expr, int convtype, int flags) |
471086d6 | 616 | { |
cd16867a | 617 | tree e = expr; |
618 | enum tree_code code = TREE_CODE (type); | |
7a979707 | 619 | const char *invalid_conv_diag; |
2b3c93a3 | 620 | tree e1; |
471086d6 | 621 | |
1bc16cab | 622 | if (error_operand_p (e) || type == error_mark_node) |
471086d6 | 623 | return error_mark_node; |
d81e00a4 | 624 | |
5b592939 | 625 | complete_type (type); |
626 | complete_type (TREE_TYPE (expr)); | |
627 | ||
7a979707 | 628 | if ((invalid_conv_diag |
629 | = targetm.invalid_conversion (TREE_TYPE (expr), type))) | |
630 | { | |
631 | error (invalid_conv_diag); | |
632 | return error_mark_node; | |
633 | } | |
634 | ||
ce984e5e | 635 | /* FIXME remove when moving to c_fully_fold model. */ |
636 | /* FIXME do we still need this test? */ | |
637 | if (!CLASS_TYPE_P (type)) | |
638 | e = integral_constant_value (e); | |
7a00f939 | 639 | if (error_operand_p (e)) |
640 | return error_mark_node; | |
7745052b | 641 | |
95397ff9 | 642 | if (MAYBE_CLASS_TYPE_P (type) && (convtype & CONV_FORCE_TEMP)) |
1a3f833b | 643 | /* We need a new temporary; don't take this shortcut. */; |
930e8175 | 644 | else if (same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (e))) |
ca23ec64 | 645 | { |
daf9ff67 | 646 | if (same_type_p (type, TREE_TYPE (e))) |
ca23ec64 | 647 | /* The call to fold will not always remove the NOP_EXPR as |
648 | might be expected, since if one of the types is a typedef; | |
755edffd | 649 | the comparison in fold is just equality of pointers, not a |
a09db423 | 650 | call to comptypes. We don't call fold in this case because |
f699c174 | 651 | that can result in infinite recursion; fold will call |
652 | convert, which will call ocp_convert, etc. */ | |
653 | return e; | |
372e0e29 | 654 | /* For complex data types, we need to perform componentwise |
653e5405 | 655 | conversion. */ |
372e0e29 | 656 | else if (TREE_CODE (type) == COMPLEX_TYPE) |
653e5405 | 657 | return fold_if_not_in_template (convert_to_complex (type, e)); |
bdb2219e | 658 | else if (TREE_CODE (e) == TARGET_EXPR) |
659 | { | |
660 | /* Don't build a NOP_EXPR of class type. Instead, change the | |
930e8175 | 661 | type of the temporary. */ |
bdb2219e | 662 | TREE_TYPE (e) = TREE_TYPE (TARGET_EXPR_SLOT (e)) = type; |
663 | return e; | |
664 | } | |
ca23ec64 | 665 | else |
092b1d6f | 666 | { |
667 | /* We shouldn't be treating objects of ADDRESSABLE type as | |
668 | rvalues. */ | |
669 | gcc_assert (!TREE_ADDRESSABLE (type)); | |
5d7ed6c7 | 670 | return fold_if_not_in_template (build_nop (type, e)); |
092b1d6f | 671 | } |
ca23ec64 | 672 | } |
673 | ||
2b3c93a3 | 674 | e1 = targetm.convert_to_type (type, e); |
675 | if (e1) | |
676 | return e1; | |
677 | ||
d81e00a4 | 678 | if (code == VOID_TYPE && (convtype & CONV_STATIC)) |
95b2ac55 | 679 | { |
dab3247a | 680 | e = convert_to_void (e, ICV_CAST, tf_warning_or_error); |
aeef2be5 | 681 | return e; |
95b2ac55 | 682 | } |
d81e00a4 | 683 | |
bb0726a1 | 684 | if (INTEGRAL_CODE_P (code)) |
471086d6 | 685 | { |
617abf06 | 686 | tree intype = TREE_TYPE (e); |
a1f05651 | 687 | tree converted; |
384590d4 | 688 | |
689 | if (TREE_CODE (type) == ENUMERAL_TYPE) | |
690 | { | |
691 | /* enum = enum, enum = int, enum = float, (enum)pointer are all | |
692 | errors. */ | |
693 | if (((INTEGRAL_OR_ENUMERATION_TYPE_P (intype) | |
653e5405 | 694 | || TREE_CODE (intype) == REAL_TYPE) |
b312a686 | 695 | && ! (convtype & CONV_STATIC)) |
384590d4 | 696 | || TREE_CODE (intype) == POINTER_TYPE) |
697 | { | |
698 | if (flags & LOOKUP_COMPLAIN) | |
2b9e3597 | 699 | permerror (input_location, "conversion from %q#T to %q#T", intype, type); |
471086d6 | 700 | |
384590d4 | 701 | if (!flag_permissive) |
702 | return error_mark_node; | |
703 | } | |
704 | ||
705 | /* [expr.static.cast] | |
706 | ||
707 | 8. A value of integral or enumeration type can be explicitly | |
708 | converted to an enumeration type. The value is unchanged if | |
709 | the original value is within the range of the enumeration | |
710 | values. Otherwise, the resulting enumeration value is | |
711 | unspecified. */ | |
bb9c1a09 | 712 | if (TREE_CODE (expr) == INTEGER_CST |
713 | && !int_fits_type_p (expr, ENUM_UNDERLYING_TYPE (type))) | |
384590d4 | 714 | warning (OPT_Wconversion, |
715 | "the result of the conversion is unspecified because " | |
716 | "%qE is outside the range of type %qT", | |
717 | expr, type); | |
471086d6 | 718 | } |
95397ff9 | 719 | if (MAYBE_CLASS_TYPE_P (intype)) |
471086d6 | 720 | { |
721 | tree rval; | |
8999978b | 722 | rval = build_type_conversion (type, e); |
6495357a | 723 | if (rval) |
724 | return rval; | |
b248d3f7 | 725 | if (flags & LOOKUP_COMPLAIN) |
0a25aad6 | 726 | error ("%q#T used where a %qT was expected", intype, type); |
471086d6 | 727 | return error_mark_node; |
728 | } | |
bb0726a1 | 729 | if (code == BOOLEAN_TYPE) |
f8913d47 | 730 | { |
731 | /* We can't implicitly convert a scoped enum to bool, so convert | |
732 | to the underlying type first. */ | |
733 | if (SCOPED_ENUM_P (intype) && (convtype & CONV_STATIC)) | |
172fff7b | 734 | e = build_nop (ENUM_UNDERLYING_TYPE (intype), e); |
f8913d47 | 735 | return cp_truthvalue_conversion (e); |
736 | } | |
ce871053 | 737 | |
a1f05651 | 738 | converted = fold_if_not_in_template (convert_to_integer (type, e)); |
739 | ||
740 | /* Ignore any integer overflow caused by the conversion. */ | |
741 | return ignore_overflows (converted, e); | |
471086d6 | 742 | } |
c7ca48ea | 743 | if (NULLPTR_TYPE_P (type) && e && null_ptr_cst_p (e)) |
6fe11077 | 744 | return nullptr_node; |
1bc16cab | 745 | if (POINTER_TYPE_P (type) || TYPE_PTR_TO_MEMBER_P (type)) |
e5ead12a | 746 | return fold_if_not_in_template (cp_convert_to_pointer (type, e)); |
684b9d79 | 747 | if (code == VECTOR_TYPE) |
c37ff371 | 748 | { |
749 | tree in_vtype = TREE_TYPE (e); | |
95397ff9 | 750 | if (MAYBE_CLASS_TYPE_P (in_vtype)) |
c37ff371 | 751 | { |
752 | tree ret_val; | |
753 | ret_val = build_type_conversion (type, e); | |
653e5405 | 754 | if (ret_val) |
755 | return ret_val; | |
756 | if (flags & LOOKUP_COMPLAIN) | |
757 | error ("%q#T used where a %qT was expected", in_vtype, type); | |
758 | return error_mark_node; | |
c37ff371 | 759 | } |
5d7ed6c7 | 760 | return fold_if_not_in_template (convert_to_vector (type, e)); |
c37ff371 | 761 | } |
c4a8ac95 | 762 | if (code == REAL_TYPE || code == COMPLEX_TYPE) |
471086d6 | 763 | { |
95397ff9 | 764 | if (MAYBE_CLASS_TYPE_P (TREE_TYPE (e))) |
471086d6 | 765 | { |
766 | tree rval; | |
8999978b | 767 | rval = build_type_conversion (type, e); |
471086d6 | 768 | if (rval) |
769 | return rval; | |
770 | else | |
b248d3f7 | 771 | if (flags & LOOKUP_COMPLAIN) |
0a25aad6 | 772 | error ("%q#T used where a floating point value was expected", |
b248d3f7 | 773 | TREE_TYPE (e)); |
471086d6 | 774 | } |
c4a8ac95 | 775 | if (code == REAL_TYPE) |
5d7ed6c7 | 776 | return fold_if_not_in_template (convert_to_real (type, e)); |
c4a8ac95 | 777 | else if (code == COMPLEX_TYPE) |
5d7ed6c7 | 778 | return fold_if_not_in_template (convert_to_complex (type, e)); |
471086d6 | 779 | } |
780 | ||
781 | /* New C++ semantics: since assignment is now based on | |
782 | memberwise copying, if the rhs type is derived from the | |
783 | lhs type, then we may still do a conversion. */ | |
95397ff9 | 784 | if (RECORD_OR_UNION_CODE_P (code)) |
471086d6 | 785 | { |
786 | tree dtype = TREE_TYPE (e); | |
c25194fd | 787 | tree ctor = NULL_TREE; |
471086d6 | 788 | |
471086d6 | 789 | dtype = TYPE_MAIN_VARIANT (dtype); |
790 | ||
471086d6 | 791 | /* Conversion between aggregate types. New C++ semantics allow |
792 | objects of derived type to be cast to objects of base type. | |
793 | Old semantics only allowed this between pointers. | |
794 | ||
795 | There may be some ambiguity between using a constructor | |
796 | vs. using a type conversion operator when both apply. */ | |
797 | ||
0a4be248 | 798 | ctor = e; |
860740a7 | 799 | |
8c18e707 | 800 | if (abstract_virtuals_error (NULL_TREE, type)) |
801 | return error_mark_node; | |
6cbb4197 | 802 | |
f82f1250 | 803 | if (BRACE_ENCLOSED_INITIALIZER_P (ctor)) |
804 | ctor = perform_implicit_conversion (type, ctor, tf_warning_or_error); | |
805 | else if ((flags & LOOKUP_ONLYCONVERTING) | |
806 | && ! (CLASS_TYPE_P (dtype) && DERIVED_FROM_P (type, dtype))) | |
fce73460 | 807 | /* For copy-initialization, first we create a temp of the proper type |
808 | with a user-defined conversion sequence, then we direct-initialize | |
809 | the target with the temp (see [dcl.init]). */ | |
810 | ctor = build_user_type_conversion (type, ctor, flags); | |
3eb89cd8 | 811 | else |
f352a3fb | 812 | { |
813 | VEC(tree,gc) *ctor_vec = make_tree_vector_single (ctor); | |
814 | ctor = build_special_member_call (NULL_TREE, | |
815 | complete_ctor_identifier, | |
816 | &ctor_vec, | |
817 | type, flags, | |
818 | tf_warning_or_error); | |
819 | release_tree_vector (ctor_vec); | |
820 | } | |
0a4be248 | 821 | if (ctor) |
3d4bed93 | 822 | return build_cplus_new (type, ctor, tf_warning_or_error); |
471086d6 | 823 | } |
824 | ||
b248d3f7 | 825 | if (flags & LOOKUP_COMPLAIN) |
a7cc1549 | 826 | { |
827 | /* If the conversion failed and expr was an invalid use of pointer to | |
828 | member function, try to report a meaningful error. */ | |
829 | if (invalid_nonstatic_memfn_p (expr, tf_warning_or_error)) | |
830 | /* We displayed the error message. */; | |
831 | else | |
832 | error ("conversion from %qT to non-scalar type %qT requested", | |
833 | TREE_TYPE (expr), type); | |
834 | } | |
471086d6 | 835 | return error_mark_node; |
836 | } | |
837 | ||
b1a8d4ce | 838 | /* When an expression is used in a void context, its value is discarded and |
839 | no lvalue-rvalue and similar conversions happen [expr.static.cast/4, | |
840 | stmt.expr/1, expr.comma/1]. This permits dereferencing an incomplete type | |
841 | in a void context. The C++ standard does not define what an `access' to an | |
63eff20d | 842 | object is, but there is reason to believe that it is the lvalue to rvalue |
b1a8d4ce | 843 | conversion -- if it were not, `*&*p = 1' would violate [expr]/4 in that it |
844 | accesses `*p' not to calculate the value to be stored. But, dcl.type.cv/8 | |
845 | indicates that volatile semantics should be the same between C and C++ | |
846 | where ever possible. C leaves it implementation defined as to what | |
847 | constitutes an access to a volatile. So, we interpret `*vp' as a read of | |
848 | the volatile object `vp' points to, unless that is an incomplete type. For | |
849 | volatile references we do not do this interpretation, because that would | |
850 | make it impossible to ignore the reference return value from functions. We | |
851 | issue warnings in the confusing cases. | |
9031d10b | 852 | |
dab3247a | 853 | The IMPLICIT is ICV_CAST when the user is explicitly converting an expression |
854 | to void via a cast. If an expression is being implicitly converted, IMPLICIT | |
855 | indicates the context of the implicit conversion. */ | |
b1a8d4ce | 856 | |
857 | tree | |
dab3247a | 858 | convert_to_void (tree expr, impl_conv_void implicit, tsubst_flags_t complain) |
b1a8d4ce | 859 | { |
9031d10b | 860 | if (expr == error_mark_node |
3d411d73 | 861 | || TREE_TYPE (expr) == error_mark_node) |
862 | return error_mark_node; | |
b2af2a93 | 863 | |
dab3247a | 864 | if (implicit == ICV_CAST) |
f94341bb | 865 | mark_exp_read (expr); |
866 | else | |
867 | { | |
868 | tree exprv = expr; | |
869 | ||
870 | while (TREE_CODE (exprv) == COMPOUND_EXPR) | |
871 | exprv = TREE_OPERAND (exprv, 1); | |
0388391d | 872 | if (DECL_P (exprv) |
873 | || handled_component_p (exprv) | |
874 | || TREE_CODE (exprv) == INDIRECT_REF) | |
f94341bb | 875 | /* Expr is not being 'used' here, otherwise we whould have |
876 | called mark_{rl}value_use use here, which would have in turn | |
877 | called mark_exp_read. Rather, we call mark_exp_read directly | |
878 | to avoid some warnings when | |
879 | -Wunused-but-set-{variable,parameter} is in effect. */ | |
880 | mark_exp_read (exprv); | |
881 | } | |
b2af2a93 | 882 | |
b1a8d4ce | 883 | if (!TREE_TYPE (expr)) |
884 | return expr; | |
ebd21de4 | 885 | if (invalid_nonstatic_memfn_p (expr, complain)) |
334f6ce1 | 886 | return error_mark_node; |
ed36f1cf | 887 | if (TREE_CODE (expr) == PSEUDO_DTOR_EXPR) |
888 | { | |
ebd21de4 | 889 | if (complain & tf_error) |
890 | error ("pseudo-destructor is not called"); | |
ed36f1cf | 891 | return error_mark_node; |
892 | } | |
e3cfe3ce | 893 | if (VOID_TYPE_P (TREE_TYPE (expr))) |
b1a8d4ce | 894 | return expr; |
895 | switch (TREE_CODE (expr)) | |
896 | { | |
897 | case COND_EXPR: | |
898 | { | |
653e5405 | 899 | /* The two parts of a cond expr might be separate lvalues. */ |
900 | tree op1 = TREE_OPERAND (expr,1); | |
901 | tree op2 = TREE_OPERAND (expr,2); | |
527facbb | 902 | bool side_effects = ((op1 && TREE_SIDE_EFFECTS (op1)) |
903 | || TREE_SIDE_EFFECTS (op2)); | |
dab3247a | 904 | tree new_op1, new_op2; |
527facbb | 905 | new_op1 = NULL_TREE; |
dab3247a | 906 | if (implicit != ICV_CAST && !side_effects) |
907 | { | |
527facbb | 908 | if (op1) |
909 | new_op1 = convert_to_void (op1, ICV_SECOND_OF_COND, complain); | |
dab3247a | 910 | new_op2 = convert_to_void (op2, ICV_THIRD_OF_COND, complain); |
911 | } | |
912 | else | |
913 | { | |
527facbb | 914 | if (op1) |
915 | new_op1 = convert_to_void (op1, ICV_CAST, complain); | |
dab3247a | 916 | new_op2 = convert_to_void (op2, ICV_CAST, complain); |
917 | } | |
9031d10b | 918 | |
527facbb | 919 | expr = build3 (COND_EXPR, TREE_TYPE (new_op2), |
831d52a2 | 920 | TREE_OPERAND (expr, 0), new_op1, new_op2); |
653e5405 | 921 | break; |
b1a8d4ce | 922 | } |
9031d10b | 923 | |
b1a8d4ce | 924 | case COMPOUND_EXPR: |
925 | { | |
653e5405 | 926 | /* The second part of a compound expr contains the value. */ |
927 | tree op1 = TREE_OPERAND (expr,1); | |
dab3247a | 928 | tree new_op1; |
929 | if (implicit != ICV_CAST && !TREE_NO_WARNING (expr)) | |
930 | new_op1 = convert_to_void (op1, ICV_RIGHT_OF_COMMA, complain); | |
931 | else | |
932 | new_op1 = convert_to_void (op1, ICV_CAST, complain); | |
9031d10b | 933 | |
653e5405 | 934 | if (new_op1 != op1) |
e907a2e9 | 935 | { |
831d52a2 | 936 | tree t = build2 (COMPOUND_EXPR, TREE_TYPE (new_op1), |
937 | TREE_OPERAND (expr, 0), new_op1); | |
e907a2e9 | 938 | expr = t; |
939 | } | |
940 | ||
653e5405 | 941 | break; |
b1a8d4ce | 942 | } |
9031d10b | 943 | |
b1a8d4ce | 944 | case NON_LVALUE_EXPR: |
945 | case NOP_EXPR: | |
c0af329c | 946 | /* These have already decayed to rvalue. */ |
b1a8d4ce | 947 | break; |
9031d10b | 948 | |
331bc0ad | 949 | case CALL_EXPR: /* We have a special meaning for volatile void fn(). */ |
b1a8d4ce | 950 | break; |
9031d10b | 951 | |
b1a8d4ce | 952 | case INDIRECT_REF: |
953 | { | |
653e5405 | 954 | tree type = TREE_TYPE (expr); |
955 | int is_reference = TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) | |
956 | == REFERENCE_TYPE; | |
957 | int is_volatile = TYPE_VOLATILE (type); | |
958 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); | |
959 | ||
dc02da7f | 960 | /* Can't load the value if we don't know the type. */ |
653e5405 | 961 | if (is_volatile && !is_complete) |
ebd21de4 | 962 | { |
963 | if (complain & tf_warning) | |
dab3247a | 964 | switch (implicit) |
965 | { | |
966 | case ICV_CAST: | |
967 | warning (0, "conversion to void will not access " | |
968 | "object of incomplete type %qT", type); | |
969 | break; | |
970 | case ICV_SECOND_OF_COND: | |
971 | warning (0, "indirection will not access object of " | |
972 | "incomplete type %qT in second operand " | |
973 | "of conditional expression", type); | |
974 | break; | |
975 | case ICV_THIRD_OF_COND: | |
976 | warning (0, "indirection will not access object of " | |
977 | "incomplete type %qT in third operand " | |
978 | "of conditional expression", type); | |
979 | break; | |
980 | case ICV_RIGHT_OF_COMMA: | |
981 | warning (0, "indirection will not access object of " | |
982 | "incomplete type %qT in right operand of " | |
983 | "comma operator", type); | |
984 | break; | |
985 | case ICV_LEFT_OF_COMMA: | |
986 | warning (0, "indirection will not access object of " | |
987 | "incomplete type %qT in left operand of " | |
988 | "comma operator", type); | |
989 | break; | |
990 | case ICV_STATEMENT: | |
991 | warning (0, "indirection will not access object of " | |
992 | "incomplete type %qT in statement", type); | |
993 | break; | |
994 | case ICV_THIRD_IN_FOR: | |
995 | warning (0, "indirection will not access object of " | |
996 | "incomplete type %qT in for increment " | |
997 | "expression", type); | |
998 | break; | |
999 | default: | |
1000 | gcc_unreachable (); | |
1001 | } | |
ebd21de4 | 1002 | } |
dc02da7f | 1003 | /* Don't load the value if this is an implicit dereference, or if |
1004 | the type needs to be handled by ctors/dtors. */ | |
dab3247a | 1005 | else if (is_volatile && is_reference) |
ebd21de4 | 1006 | { |
1007 | if (complain & tf_warning) | |
dab3247a | 1008 | switch (implicit) |
1009 | { | |
1010 | case ICV_CAST: | |
1011 | warning (0, "conversion to void will not access " | |
1012 | "object of type %qT", type); | |
1013 | break; | |
1014 | case ICV_SECOND_OF_COND: | |
1015 | warning (0, "implicit dereference will not access object " | |
1016 | "of type %qT in second operand of " | |
1017 | "conditional expression", type); | |
1018 | break; | |
1019 | case ICV_THIRD_OF_COND: | |
1020 | warning (0, "implicit dereference will not access object " | |
1021 | "of type %qT in third operand of " | |
1022 | "conditional expression", type); | |
1023 | break; | |
1024 | case ICV_RIGHT_OF_COMMA: | |
1025 | warning (0, "implicit dereference will not access object " | |
1026 | "of type %qT in right operand of " | |
1027 | "comma operator", type); | |
1028 | break; | |
1029 | case ICV_LEFT_OF_COMMA: | |
1030 | warning (0, "implicit dereference will not access object " | |
1031 | "of type %qT in left operand of comma operator", | |
1032 | type); | |
1033 | break; | |
1034 | case ICV_STATEMENT: | |
1035 | warning (0, "implicit dereference will not access object " | |
1036 | "of type %qT in statement", type); | |
1037 | break; | |
1038 | case ICV_THIRD_IN_FOR: | |
1039 | warning (0, "implicit dereference will not access object " | |
1040 | "of type %qT in for increment expression", | |
1041 | type); | |
1042 | break; | |
1043 | default: | |
1044 | gcc_unreachable (); | |
1045 | } | |
ebd21de4 | 1046 | } |
dab3247a | 1047 | else if (is_volatile && TREE_ADDRESSABLE (type)) |
1048 | { | |
1049 | if (complain & tf_warning) | |
1050 | switch (implicit) | |
1051 | { | |
1052 | case ICV_CAST: | |
1053 | warning (0, "conversion to void will not access " | |
1054 | "object of non-trivially-copyable type %qT", | |
1055 | type); | |
1056 | break; | |
1057 | case ICV_SECOND_OF_COND: | |
1058 | warning (0, "indirection will not access object of " | |
1059 | "non-trivially-copyable type %qT in second " | |
1060 | "operand of conditional expression", type); | |
1061 | break; | |
1062 | case ICV_THIRD_OF_COND: | |
1063 | warning (0, "indirection will not access object of " | |
1064 | "non-trivially-copyable type %qT in third " | |
1065 | "operand of conditional expression", type); | |
1066 | break; | |
1067 | case ICV_RIGHT_OF_COMMA: | |
1068 | warning (0, "indirection will not access object of " | |
1069 | "non-trivially-copyable type %qT in right " | |
1070 | "operand of comma operator", type); | |
1071 | break; | |
1072 | case ICV_LEFT_OF_COMMA: | |
1073 | warning (0, "indirection will not access object of " | |
1074 | "non-trivially-copyable type %qT in left " | |
1075 | "operand of comma operator", type); | |
1076 | break; | |
1077 | case ICV_STATEMENT: | |
1078 | warning (0, "indirection will not access object of " | |
1079 | "non-trivially-copyable type %qT in statement", | |
1080 | type); | |
1081 | break; | |
1082 | case ICV_THIRD_IN_FOR: | |
1083 | warning (0, "indirection will not access object of " | |
1084 | "non-trivially-copyable type %qT in for " | |
1085 | "increment expression", type); | |
1086 | break; | |
1087 | default: | |
1088 | gcc_unreachable (); | |
1089 | } | |
1090 | } | |
dc02da7f | 1091 | if (is_reference || !is_volatile || !is_complete || TREE_ADDRESSABLE (type)) |
a4d4030b | 1092 | { |
1093 | /* Emit a warning (if enabled) when the "effect-less" INDIRECT_REF | |
1094 | operation is stripped off. Note that we don't warn about | |
1095 | - an expression with TREE_NO_WARNING set. (For an example of | |
1096 | such expressions, see build_over_call in call.c.) | |
1097 | - automatic dereferencing of references, since the user cannot | |
1098 | control it. (See also warn_if_unused_value() in stmt.c.) */ | |
1099 | if (warn_unused_value | |
dab3247a | 1100 | && implicit != ICV_CAST |
a4d4030b | 1101 | && (complain & tf_warning) |
1102 | && !TREE_NO_WARNING (expr) | |
1103 | && !is_reference) | |
1104 | warning (OPT_Wunused_value, "value computed is not used"); | |
1105 | expr = TREE_OPERAND (expr, 0); | |
1106 | } | |
653e5405 | 1107 | |
1108 | break; | |
b1a8d4ce | 1109 | } |
9031d10b | 1110 | |
b1a8d4ce | 1111 | case VAR_DECL: |
1112 | { | |
653e5405 | 1113 | /* External variables might be incomplete. */ |
1114 | tree type = TREE_TYPE (expr); | |
1115 | int is_complete = COMPLETE_TYPE_P (complete_type (type)); | |
1116 | ||
ebd21de4 | 1117 | if (TYPE_VOLATILE (type) && !is_complete && (complain & tf_warning)) |
dab3247a | 1118 | switch (implicit) |
1119 | { | |
1120 | case ICV_CAST: | |
1121 | warning (0, "conversion to void will not access " | |
1122 | "object %qE of incomplete type %qT", expr, type); | |
1123 | break; | |
1124 | case ICV_SECOND_OF_COND: | |
1125 | warning (0, "variable %qE of incomplete type %qT will not " | |
1126 | "be accessed in second operand of " | |
1127 | "conditional expression", expr, type); | |
1128 | break; | |
1129 | case ICV_THIRD_OF_COND: | |
1130 | warning (0, "variable %qE of incomplete type %qT will not " | |
1131 | "be accessed in third operand of " | |
1132 | "conditional expression", expr, type); | |
1133 | break; | |
1134 | case ICV_RIGHT_OF_COMMA: | |
1135 | warning (0, "variable %qE of incomplete type %qT will not " | |
1136 | "be accessed in right operand of comma operator", | |
1137 | expr, type); | |
1138 | break; | |
1139 | case ICV_LEFT_OF_COMMA: | |
1140 | warning (0, "variable %qE of incomplete type %qT will not " | |
1141 | "be accessed in left operand of comma operator", | |
1142 | expr, type); | |
1143 | break; | |
1144 | case ICV_STATEMENT: | |
1145 | warning (0, "variable %qE of incomplete type %qT will not " | |
1146 | "be accessed in statement", expr, type); | |
1147 | break; | |
1148 | case ICV_THIRD_IN_FOR: | |
1149 | warning (0, "variable %qE of incomplete type %qT will not " | |
1150 | "be accessed in for increment expression", | |
1151 | expr, type); | |
1152 | break; | |
1153 | default: | |
1154 | gcc_unreachable (); | |
1155 | } | |
1156 | ||
653e5405 | 1157 | break; |
b1a8d4ce | 1158 | } |
d9f88785 | 1159 | |
25b3017b | 1160 | case TARGET_EXPR: |
1161 | /* Don't bother with the temporary object returned from a function if | |
1162 | we don't use it and don't need to destroy it. We'll still | |
1163 | allocate space for it in expand_call or declare_return_variable, | |
1164 | but we don't need to track it through all the tree phases. */ | |
67bb1301 | 1165 | if (TARGET_EXPR_IMPLICIT_P (expr) |
25b3017b | 1166 | && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (expr))) |
1167 | { | |
1168 | tree init = TARGET_EXPR_INITIAL (expr); | |
1169 | if (TREE_CODE (init) == AGGR_INIT_EXPR | |
1170 | && !AGGR_INIT_VIA_CTOR_P (init)) | |
1171 | { | |
c2f47e15 | 1172 | tree fn = AGGR_INIT_EXPR_FN (init); |
389dd41b | 1173 | expr = build_call_array_loc (input_location, |
1174 | TREE_TYPE (TREE_TYPE (TREE_TYPE (fn))), | |
1175 | fn, | |
1176 | aggr_init_expr_nargs (init), | |
1177 | AGGR_INIT_EXPR_ARGP (init)); | |
25b3017b | 1178 | } |
1179 | } | |
1180 | break; | |
1181 | ||
b1a8d4ce | 1182 | default:; |
1183 | } | |
eebd67e7 | 1184 | expr = resolve_nondeduced_context (expr); |
b1a8d4ce | 1185 | { |
1186 | tree probe = expr; | |
9031d10b | 1187 | |
b1a8d4ce | 1188 | if (TREE_CODE (probe) == ADDR_EXPR) |
1189 | probe = TREE_OPERAND (expr, 0); | |
2e0e6579 | 1190 | if (type_unknown_p (probe)) |
1191 | { | |
1192 | /* [over.over] enumerates the places where we can take the address | |
1193 | of an overloaded function, and this is not one of them. */ | |
ebd21de4 | 1194 | if (complain & tf_error) |
dab3247a | 1195 | switch (implicit) |
1196 | { | |
1197 | case ICV_CAST: | |
1198 | error ("conversion to void " | |
1199 | "cannot resolve address of overloaded function"); | |
1200 | break; | |
1201 | case ICV_SECOND_OF_COND: | |
1202 | error ("second operand of conditional expression " | |
1203 | "cannot resolve address of overloaded function"); | |
1204 | break; | |
1205 | case ICV_THIRD_OF_COND: | |
1206 | error ("third operand of conditional expression " | |
1207 | "cannot resolve address of overloaded function"); | |
1208 | break; | |
1209 | case ICV_RIGHT_OF_COMMA: | |
1210 | error ("right operand of comma operator " | |
1211 | "cannot resolve address of overloaded function"); | |
1212 | break; | |
1213 | case ICV_LEFT_OF_COMMA: | |
1214 | error ("left operand of comma operator " | |
1215 | "cannot resolve address of overloaded function"); | |
1216 | break; | |
1217 | case ICV_STATEMENT: | |
1218 | error ("statement " | |
1219 | "cannot resolve address of overloaded function"); | |
1220 | break; | |
1221 | case ICV_THIRD_IN_FOR: | |
1222 | error ("for increment expression " | |
1223 | "cannot resolve address of overloaded function"); | |
1224 | break; | |
1225 | } | |
ebd21de4 | 1226 | else |
1227 | return error_mark_node; | |
ea720917 | 1228 | expr = void_zero_node; |
2e0e6579 | 1229 | } |
dab3247a | 1230 | else if (implicit != ICV_CAST && probe == expr && is_overloaded_fn (probe)) |
2056769e | 1231 | { |
1232 | /* Only warn when there is no &. */ | |
ebd21de4 | 1233 | if (complain & tf_warning) |
dab3247a | 1234 | switch (implicit) |
1235 | { | |
1236 | case ICV_SECOND_OF_COND: | |
1237 | warning (OPT_Waddress, | |
1238 | "second operand of conditional expression " | |
1239 | "is a reference, not call, to function %qE", expr); | |
1240 | break; | |
1241 | case ICV_THIRD_OF_COND: | |
1242 | warning (OPT_Waddress, | |
1243 | "third operand of conditional expression " | |
1244 | "is a reference, not call, to function %qE", expr); | |
1245 | break; | |
1246 | case ICV_RIGHT_OF_COMMA: | |
1247 | warning (OPT_Waddress, | |
1248 | "right operand of comma operator " | |
1249 | "is a reference, not call, to function %qE", expr); | |
1250 | break; | |
1251 | case ICV_LEFT_OF_COMMA: | |
1252 | warning (OPT_Waddress, | |
1253 | "left operand of comma operator " | |
1254 | "is a reference, not call, to function %qE", expr); | |
1255 | break; | |
1256 | case ICV_STATEMENT: | |
1257 | warning (OPT_Waddress, | |
1258 | "statement is a reference, not call, to function %qE", | |
1259 | expr); | |
1260 | break; | |
1261 | case ICV_THIRD_IN_FOR: | |
1262 | warning (OPT_Waddress, | |
1263 | "for increment expression " | |
1264 | "is a reference, not call, to function %qE", expr); | |
1265 | break; | |
1266 | default: | |
1267 | gcc_unreachable (); | |
1268 | } | |
1269 | ||
2056769e | 1270 | if (TREE_CODE (expr) == COMPONENT_REF) |
1271 | expr = TREE_OPERAND (expr, 0); | |
1272 | } | |
b1a8d4ce | 1273 | } |
9031d10b | 1274 | |
e3cfe3ce | 1275 | if (expr != error_mark_node && !VOID_TYPE_P (TREE_TYPE (expr))) |
b1a8d4ce | 1276 | { |
dab3247a | 1277 | if (implicit != ICV_CAST |
5e2a4133 | 1278 | && warn_unused_value |
1279 | && !TREE_NO_WARNING (expr) | |
1280 | && !processing_template_decl) | |
1fe46df1 | 1281 | { |
1282 | /* The middle end does not warn about expressions that have | |
1283 | been explicitly cast to void, so we must do so here. */ | |
ebd21de4 | 1284 | if (!TREE_SIDE_EFFECTS (expr)) { |
1285 | if (complain & tf_warning) | |
dab3247a | 1286 | switch (implicit) |
1287 | { | |
1288 | case ICV_SECOND_OF_COND: | |
1289 | warning (OPT_Wunused_value, | |
1290 | "second operand of conditional expression has no effect"); | |
1291 | break; | |
1292 | case ICV_THIRD_OF_COND: | |
1293 | warning (OPT_Wunused_value, | |
1294 | "third operand of conditional expression has no effect"); | |
1295 | break; | |
1296 | case ICV_RIGHT_OF_COMMA: | |
1297 | warning (OPT_Wunused_value, | |
1298 | "right operand of comma operator has no effect"); | |
1299 | break; | |
1300 | case ICV_LEFT_OF_COMMA: | |
1301 | warning (OPT_Wunused_value, | |
1302 | "left operand of comma operator has no effect"); | |
1303 | break; | |
1304 | case ICV_STATEMENT: | |
1305 | warning (OPT_Wunused_value, | |
1306 | "statement has no effect"); | |
1307 | break; | |
1308 | case ICV_THIRD_IN_FOR: | |
1309 | warning (OPT_Wunused_value, | |
1310 | "for increment expression has no effect"); | |
1311 | break; | |
1312 | default: | |
1313 | gcc_unreachable (); | |
1314 | } | |
ebd21de4 | 1315 | } |
9031d10b | 1316 | else |
1317 | { | |
1fe46df1 | 1318 | tree e; |
1319 | enum tree_code code; | |
607a5d68 | 1320 | enum tree_code_class tclass; |
9031d10b | 1321 | |
1fe46df1 | 1322 | e = expr; |
1323 | /* We might like to warn about (say) "(int) f()", as the | |
1324 | cast has no effect, but the compiler itself will | |
1325 | generate implicit conversions under some | |
324d8f2d | 1326 | circumstances. (For example a block copy will be |
1fe46df1 | 1327 | turned into a call to "__builtin_memcpy", with a |
1328 | conversion of the return value to an appropriate | |
1329 | type.) So, to avoid false positives, we strip | |
416ce344 | 1330 | conversions. Do not use STRIP_NOPs because it will |
1331 | not strip conversions to "void", as that is not a | |
1332 | mode-preserving conversion. */ | |
1333 | while (TREE_CODE (e) == NOP_EXPR) | |
1334 | e = TREE_OPERAND (e, 0); | |
1fe46df1 | 1335 | |
1336 | code = TREE_CODE (e); | |
607a5d68 | 1337 | tclass = TREE_CODE_CLASS (code); |
1338 | if ((tclass == tcc_comparison | |
1339 | || tclass == tcc_unary | |
1340 | || (tclass == tcc_binary | |
1fe46df1 | 1341 | && !(code == MODIFY_EXPR |
1342 | || code == INIT_EXPR | |
1343 | || code == PREDECREMENT_EXPR | |
1344 | || code == PREINCREMENT_EXPR | |
1345 | || code == POSTDECREMENT_EXPR | |
1346 | || code == POSTINCREMENT_EXPR))) | |
ebd21de4 | 1347 | && (complain & tf_warning)) |
ced7c954 | 1348 | warning (OPT_Wunused_value, "value computed is not used"); |
1fe46df1 | 1349 | } |
1350 | } | |
00fa9079 | 1351 | expr = build1 (CONVERT_EXPR, void_type_node, expr); |
b1a8d4ce | 1352 | } |
de5ad4cb | 1353 | if (! TREE_SIDE_EFFECTS (expr)) |
1354 | expr = void_zero_node; | |
b1a8d4ce | 1355 | return expr; |
1356 | } | |
1357 | ||
d81e00a4 | 1358 | /* Create an expression whose value is that of EXPR, |
1359 | converted to type TYPE. The TREE_TYPE of the value | |
1360 | is always TYPE. This function implements all reasonable | |
1361 | conversions; callers should filter out those that are | |
c4a8ac95 | 1362 | not permitted by the language being compiled. |
1363 | ||
1364 | Most of this routine is from build_reinterpret_cast. | |
1365 | ||
a17c2a3a | 1366 | The back end cannot call cp_convert (what was convert) because |
c4a8ac95 | 1367 | conversions to/from basetypes may involve memory references |
1368 | (vbases) and adding or subtracting small values (multiple | |
1369 | inheritance), but it calls convert from the constant folding code | |
e0aa5007 | 1370 | on subtrees of already built trees after it has ripped them apart. |
c4a8ac95 | 1371 | |
1372 | Also, if we ever support range variables, we'll probably also have to | |
1373 | do a little bit more work. */ | |
d81e00a4 | 1374 | |
1375 | tree | |
35771a9a | 1376 | convert (tree type, tree expr) |
d81e00a4 | 1377 | { |
c4a8ac95 | 1378 | tree intype; |
1379 | ||
1380 | if (type == error_mark_node || expr == error_mark_node) | |
1381 | return error_mark_node; | |
1382 | ||
c4a8ac95 | 1383 | intype = TREE_TYPE (expr); |
1384 | ||
6686e84d | 1385 | if (POINTER_TYPE_P (type) && POINTER_TYPE_P (intype)) |
13f0eb20 | 1386 | return fold_if_not_in_template (build_nop (type, expr)); |
c4a8ac95 | 1387 | |
1388 | return ocp_convert (type, expr, CONV_OLD_CONVERT, | |
1389 | LOOKUP_NORMAL|LOOKUP_NO_CONVERSION); | |
d81e00a4 | 1390 | } |
1391 | ||
c4a8ac95 | 1392 | /* Like cp_convert, except permit conversions to take place which |
471086d6 | 1393 | are not normally allowed due to access restrictions |
1394 | (such as conversion from sub-type to private super-type). */ | |
96624a9e | 1395 | |
471086d6 | 1396 | tree |
35771a9a | 1397 | convert_force (tree type, tree expr, int convtype) |
471086d6 | 1398 | { |
cd16867a | 1399 | tree e = expr; |
1400 | enum tree_code code = TREE_CODE (type); | |
471086d6 | 1401 | |
1402 | if (code == REFERENCE_TYPE) | |
9031d10b | 1403 | return (fold_if_not_in_template |
5d7ed6c7 | 1404 | (convert_to_reference (type, e, CONV_C_CAST, LOOKUP_COMPLAIN, |
1405 | NULL_TREE))); | |
471086d6 | 1406 | |
1407 | if (code == POINTER_TYPE) | |
5d7ed6c7 | 1408 | return fold_if_not_in_template (convert_to_pointer_force (type, e)); |
471086d6 | 1409 | |
ac9386a0 | 1410 | /* From typeck.c convert_for_assignment */ |
471086d6 | 1411 | if (((TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE && TREE_CODE (e) == ADDR_EXPR |
1412 | && TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE | |
1413 | && TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE) | |
ac9386a0 | 1414 | || integer_zerop (e) |
1415 | || TYPE_PTRMEMFUNC_P (TREE_TYPE (e))) | |
471086d6 | 1416 | && TYPE_PTRMEMFUNC_P (type)) |
cb02169c | 1417 | /* compatible pointer to member functions. */ |
1418 | return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1, | |
85132186 | 1419 | /*c_cast_p=*/1, tf_warning_or_error); |
a74e8896 | 1420 | |
c4a8ac95 | 1421 | return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL); |
471086d6 | 1422 | } |
1423 | ||
471086d6 | 1424 | /* Convert an aggregate EXPR to type XTYPE. If a conversion |
1425 | exists, return the attempted conversion. This may | |
1426 | return ERROR_MARK_NODE if the conversion is not | |
1427 | allowed (references private members, etc). | |
1428 | If no conversion exists, NULL_TREE is returned. | |
1429 | ||
ce28ee2e | 1430 | FIXME: Ambiguity checking is wrong. Should choose one by the implicit |
1431 | object parameter, or by the second standard conversion sequence if | |
1432 | that doesn't do it. This will probably wait for an overloading rewrite. | |
1433 | (jason 8/9/95) */ | |
471086d6 | 1434 | |
ef9571e5 | 1435 | static tree |
8999978b | 1436 | build_type_conversion (tree xtype, tree expr) |
471086d6 | 1437 | { |
1438 | /* C++: check to see if we can convert this aggregate type | |
bcf789d7 | 1439 | into the required type. */ |
8999978b | 1440 | return build_user_type_conversion (xtype, expr, LOOKUP_NORMAL); |
471086d6 | 1441 | } |
1442 | ||
1e66592c | 1443 | /* Convert the given EXPR to one of a group of types suitable for use in an |
1444 | expression. DESIRES is a combination of various WANT_* flags (q.v.) | |
35771a9a | 1445 | which indicates which types are suitable. If COMPLAIN is true, complain |
1e66592c | 1446 | about ambiguity; otherwise, the caller will deal with it. */ |
471086d6 | 1447 | |
1e66592c | 1448 | tree |
35771a9a | 1449 | build_expr_type_conversion (int desires, tree expr, bool complain) |
471086d6 | 1450 | { |
1e66592c | 1451 | tree basetype = TREE_TYPE (expr); |
6a44e72e | 1452 | tree conv = NULL_TREE; |
bdd152ce | 1453 | tree winner = NULL_TREE; |
471086d6 | 1454 | |
9031d10b | 1455 | if (expr == null_node |
1456 | && (desires & WANT_INT) | |
954885ed | 1457 | && !(desires & WANT_NULL)) |
8296fdaa | 1458 | warning_at (input_location, OPT_Wconversion_null, |
1459 | "converting NULL to non-pointer type"); | |
9031d10b | 1460 | |
ce28ee2e | 1461 | basetype = TREE_TYPE (expr); |
471086d6 | 1462 | |
3d411d73 | 1463 | if (basetype == error_mark_node) |
1464 | return error_mark_node; | |
1465 | ||
95397ff9 | 1466 | if (! MAYBE_CLASS_TYPE_P (basetype)) |
bdd152ce | 1467 | switch (TREE_CODE (basetype)) |
1468 | { | |
1469 | case INTEGER_TYPE: | |
954885ed | 1470 | if ((desires & WANT_NULL) && null_ptr_cst_p (expr)) |
bdd152ce | 1471 | return expr; |
1472 | /* else fall through... */ | |
1473 | ||
1474 | case BOOLEAN_TYPE: | |
1475 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1476 | case ENUMERAL_TYPE: | |
1477 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1478 | case REAL_TYPE: | |
1479 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1480 | case POINTER_TYPE: | |
1481 | return (desires & WANT_POINTER) ? expr : NULL_TREE; | |
9031d10b | 1482 | |
bdd152ce | 1483 | case FUNCTION_TYPE: |
1484 | case ARRAY_TYPE: | |
a681799d | 1485 | return (desires & WANT_POINTER) ? decay_conversion (expr) |
653e5405 | 1486 | : NULL_TREE; |
96ec9e30 | 1487 | |
64ec1ad6 | 1488 | case COMPLEX_TYPE: |
96ec9e30 | 1489 | case VECTOR_TYPE: |
64ec1ad6 | 1490 | if ((desires & WANT_VECTOR_OR_COMPLEX) == 0) |
96ec9e30 | 1491 | return NULL_TREE; |
1492 | switch (TREE_CODE (TREE_TYPE (basetype))) | |
1493 | { | |
1494 | case INTEGER_TYPE: | |
1495 | case BOOLEAN_TYPE: | |
1496 | return (desires & WANT_INT) ? expr : NULL_TREE; | |
1497 | case ENUMERAL_TYPE: | |
1498 | return (desires & WANT_ENUM) ? expr : NULL_TREE; | |
1499 | case REAL_TYPE: | |
1500 | return (desires & WANT_FLOAT) ? expr : NULL_TREE; | |
1501 | default: | |
1502 | return NULL_TREE; | |
1503 | } | |
1504 | ||
bdd152ce | 1505 | default: |
1506 | return NULL_TREE; | |
1507 | } | |
1508 | ||
1509 | /* The code for conversions from class type is currently only used for | |
1510 | delete expressions. Other expressions are handled by build_new_op. */ | |
a5f2d620 | 1511 | if (!complete_type_or_maybe_complain (basetype, expr, complain)) |
f8182e08 | 1512 | return error_mark_node; |
1513 | if (!TYPE_HAS_CONVERSION (basetype)) | |
bdd152ce | 1514 | return NULL_TREE; |
1515 | ||
9960d752 | 1516 | for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv)) |
bdd152ce | 1517 | { |
1518 | int win = 0; | |
1519 | tree candidate; | |
1520 | tree cand = TREE_VALUE (conv); | |
c1ca2f12 | 1521 | cand = OVL_CURRENT (cand); |
bdd152ce | 1522 | |
1523 | if (winner && winner == cand) | |
1524 | continue; | |
1525 | ||
cf7aa2e5 | 1526 | if (DECL_NONCONVERTING_P (cand)) |
1527 | continue; | |
1528 | ||
ef4534a3 | 1529 | candidate = non_reference (TREE_TYPE (TREE_TYPE (cand))); |
bdd152ce | 1530 | |
1531 | switch (TREE_CODE (candidate)) | |
1532 | { | |
1533 | case BOOLEAN_TYPE: | |
1534 | case INTEGER_TYPE: | |
1535 | win = (desires & WANT_INT); break; | |
1536 | case ENUMERAL_TYPE: | |
1537 | win = (desires & WANT_ENUM); break; | |
1538 | case REAL_TYPE: | |
1539 | win = (desires & WANT_FLOAT); break; | |
1540 | case POINTER_TYPE: | |
1541 | win = (desires & WANT_POINTER); break; | |
1542 | ||
64ec1ad6 | 1543 | case COMPLEX_TYPE: |
96ec9e30 | 1544 | case VECTOR_TYPE: |
64ec1ad6 | 1545 | if ((desires & WANT_VECTOR_OR_COMPLEX) == 0) |
96ec9e30 | 1546 | break; |
1547 | switch (TREE_CODE (TREE_TYPE (candidate))) | |
1548 | { | |
1549 | case BOOLEAN_TYPE: | |
1550 | case INTEGER_TYPE: | |
1551 | win = (desires & WANT_INT); break; | |
1552 | case ENUMERAL_TYPE: | |
1553 | win = (desires & WANT_ENUM); break; | |
1554 | case REAL_TYPE: | |
1555 | win = (desires & WANT_FLOAT); break; | |
1556 | default: | |
1557 | break; | |
1558 | } | |
1559 | break; | |
1560 | ||
bdd152ce | 1561 | default: |
1562 | break; | |
1563 | } | |
1564 | ||
1565 | if (win) | |
1566 | { | |
1567 | if (winner) | |
1568 | { | |
1569 | if (complain) | |
1570 | { | |
0a25aad6 | 1571 | error ("ambiguous default type conversion from %qT", |
653e5405 | 1572 | basetype); |
0a25aad6 | 1573 | error (" candidate conversions include %qD and %qD", |
653e5405 | 1574 | winner, cand); |
bdd152ce | 1575 | } |
1576 | return error_mark_node; | |
1577 | } | |
1578 | else | |
1579 | winner = cand; | |
1580 | } | |
1581 | } | |
1e66592c | 1582 | |
bdd152ce | 1583 | if (winner) |
1584 | { | |
ef4534a3 | 1585 | tree type = non_reference (TREE_TYPE (TREE_TYPE (winner))); |
bdd152ce | 1586 | return build_user_type_conversion (type, expr, LOOKUP_NORMAL); |
471086d6 | 1587 | } |
1e66592c | 1588 | |
985e9ee0 | 1589 | return NULL_TREE; |
471086d6 | 1590 | } |
bc3887cf | 1591 | |
96624a9e | 1592 | /* Implements integral promotion (4.1) and float->double promotion. */ |
1593 | ||
bc3887cf | 1594 | tree |
35771a9a | 1595 | type_promotes_to (tree type) |
bc3887cf | 1596 | { |
2b3c93a3 | 1597 | tree promoted_type; |
1598 | ||
ce28ee2e | 1599 | if (type == error_mark_node) |
1600 | return error_mark_node; | |
1601 | ||
bc3887cf | 1602 | type = TYPE_MAIN_VARIANT (type); |
bb0726a1 | 1603 | |
2b3c93a3 | 1604 | /* Check for promotions of target-defined types first. */ |
1605 | promoted_type = targetm.promoted_type (type); | |
1606 | if (promoted_type) | |
1607 | return promoted_type; | |
1608 | ||
bb0726a1 | 1609 | /* bool always promotes to int (not unsigned), even if it's the same |
1610 | size. */ | |
9e1a8234 | 1611 | if (TREE_CODE (type) == BOOLEAN_TYPE) |
bb0726a1 | 1612 | type = integer_type_node; |
1613 | ||
1614 | /* Normally convert enums to int, but convert wide enums to something | |
1615 | wider. */ | |
1616 | else if (TREE_CODE (type) == ENUMERAL_TYPE | |
924bbf02 | 1617 | || type == char16_type_node |
1618 | || type == char32_type_node | |
bb0726a1 | 1619 | || type == wchar_type_node) |
6c9497b1 | 1620 | { |
1621 | int precision = MAX (TYPE_PRECISION (type), | |
1622 | TYPE_PRECISION (integer_type_node)); | |
771d21fa | 1623 | tree totype = c_common_type_for_size (precision, 0); |
bb9c1a09 | 1624 | if (TREE_CODE (type) == ENUMERAL_TYPE) |
1625 | type = ENUM_UNDERLYING_TYPE (type); | |
78a8ed03 | 1626 | if (TYPE_UNSIGNED (type) |
6c9497b1 | 1627 | && ! int_fits_type_p (TYPE_MAX_VALUE (type), totype)) |
771d21fa | 1628 | type = c_common_type_for_size (precision, 1); |
6c9497b1 | 1629 | else |
1630 | type = totype; | |
1631 | } | |
d7aeef06 | 1632 | else if (c_promoting_integer_type_p (type)) |
bc3887cf | 1633 | { |
d0acef9e | 1634 | /* Retain unsignedness if really not getting bigger. */ |
78a8ed03 | 1635 | if (TYPE_UNSIGNED (type) |
d0acef9e | 1636 | && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) |
bc3887cf | 1637 | type = unsigned_type_node; |
1638 | else | |
1639 | type = integer_type_node; | |
1640 | } | |
1641 | else if (type == float_type_node) | |
1642 | type = double_type_node; | |
9031d10b | 1643 | |
a681799d | 1644 | return type; |
bc3887cf | 1645 | } |
668ae905 | 1646 | |
668ae905 | 1647 | /* The routines below this point are carefully written to conform to |
1648 | the standard. They use the same terminology, and follow the rules | |
1649 | closely. Although they are used only in pt.c at the moment, they | |
1650 | should presumably be used everywhere in the future. */ | |
1651 | ||
1146f179 | 1652 | /* Attempt to perform qualification conversions on EXPR to convert it |
1653 | to TYPE. Return the resulting expression, or error_mark_node if | |
1654 | the conversion was impossible. */ | |
1655 | ||
9031d10b | 1656 | tree |
35771a9a | 1657 | perform_qualification_conversions (tree type, tree expr) |
668ae905 | 1658 | { |
1bc16cab | 1659 | tree expr_type; |
1660 | ||
1661 | expr_type = TREE_TYPE (expr); | |
1662 | ||
3b087710 | 1663 | if (same_type_p (type, expr_type)) |
1664 | return expr; | |
1665 | else if (TYPE_PTR_P (type) && TYPE_PTR_P (expr_type) | |
1666 | && comp_ptr_ttypes (TREE_TYPE (type), TREE_TYPE (expr_type))) | |
1bc16cab | 1667 | return build_nop (type, expr); |
1668 | else if (TYPE_PTR_TO_MEMBER_P (type) | |
1669 | && TYPE_PTR_TO_MEMBER_P (expr_type) | |
1670 | && same_type_p (TYPE_PTRMEM_CLASS_TYPE (type), | |
1671 | TYPE_PTRMEM_CLASS_TYPE (expr_type)) | |
1672 | && comp_ptr_ttypes (TYPE_PTRMEM_POINTED_TO_TYPE (type), | |
1673 | TYPE_PTRMEM_POINTED_TO_TYPE (expr_type))) | |
1674 | return build_nop (type, expr); | |
1146f179 | 1675 | else |
1676 | return error_mark_node; | |
668ae905 | 1677 | } |