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0f4cea33 | 1 | /* Diagnostic routines shared by all languages that are variants of C. |
fbd26352 | 2 | Copyright (C) 1992-2019 Free Software Foundation, Inc. |
0f4cea33 | 3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
8 | Software Foundation; either version 3, or (at your option) any later | |
9 | version. | |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GCC; see the file COPYING3. If not see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "target.h" | |
24 | #include "function.h" | |
25 | #include "tree.h" | |
26 | #include "c-common.h" | |
ad7b10a2 | 27 | #include "memmodel.h" |
0f4cea33 | 28 | #include "tm_p.h" |
29 | #include "diagnostic.h" | |
30 | #include "intl.h" | |
30a86690 | 31 | #include "stringpool.h" |
32 | #include "attribs.h" | |
629b6abc | 33 | #include "asan.h" |
9bf6a8e0 | 34 | #include "gcc-rich-location.h" |
1a2d3e8e | 35 | #include "gimplify.h" |
2bfb0686 | 36 | #include "c-family/c-indentation.h" |
0eff2551 | 37 | #include "calls.h" |
8144bd52 | 38 | #include "stor-layout.h" |
0f4cea33 | 39 | |
40 | /* Print a warning if a constant expression had overflow in folding. | |
41 | Invoke this function on every expression that the language | |
42 | requires to be a constant expression. | |
43 | Note the ANSI C standard says it is erroneous for a | |
44 | constant expression to overflow. */ | |
45 | ||
46 | void | |
47 | constant_expression_warning (tree value) | |
48 | { | |
49 | if (warn_overflow && pedantic | |
50 | && (TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST | |
51 | || TREE_CODE (value) == FIXED_CST | |
52 | || TREE_CODE (value) == VECTOR_CST | |
53 | || TREE_CODE (value) == COMPLEX_CST) | |
54 | && TREE_OVERFLOW (value)) | |
55 | pedwarn (input_location, OPT_Woverflow, "overflow in constant expression"); | |
56 | } | |
57 | ||
58 | /* The same as above but print an unconditional error. */ | |
59 | ||
60 | void | |
61 | constant_expression_error (tree value) | |
62 | { | |
63 | if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST | |
64 | || TREE_CODE (value) == FIXED_CST | |
65 | || TREE_CODE (value) == VECTOR_CST | |
66 | || TREE_CODE (value) == COMPLEX_CST) | |
67 | && TREE_OVERFLOW (value)) | |
68 | error ("overflow in constant expression"); | |
69 | } | |
70 | ||
645b0f8d | 71 | /* Print a warning if an expression result VALUE had an overflow |
72 | in folding and its operands hadn't. EXPR, which may be null, is | |
73 | the operand of the expression. | |
0f4cea33 | 74 | |
75 | Invoke this function on every expression that | |
76 | (1) appears in the source code, and | |
77 | (2) is a constant expression that overflowed, and | |
78 | (3) is not already checked by convert_and_check; | |
79 | however, do not invoke this function on operands of explicit casts | |
80 | or when the expression is the result of an operator and any operand | |
81 | already overflowed. */ | |
82 | ||
83 | void | |
645b0f8d | 84 | overflow_warning (location_t loc, tree value, tree expr) |
0f4cea33 | 85 | { |
86 | if (c_inhibit_evaluation_warnings != 0) | |
87 | return; | |
88 | ||
645b0f8d | 89 | const char *warnfmt = NULL; |
90 | ||
0f4cea33 | 91 | switch (TREE_CODE (value)) |
92 | { | |
93 | case INTEGER_CST: | |
645b0f8d | 94 | warnfmt = (expr |
95 | ? G_("integer overflow in expression %qE of type %qT " | |
96 | "results in %qE") | |
97 | : G_("integer overflow in expression of type %qT " | |
98 | "results in %qE")); | |
0f4cea33 | 99 | break; |
100 | ||
101 | case REAL_CST: | |
645b0f8d | 102 | warnfmt = (expr |
b2312729 | 103 | ? G_("floating point overflow in expression %qE " |
104 | "of type %qT results in %qE") | |
105 | : G_("floating point overflow in expression of type %qT " | |
106 | "results in %qE")); | |
0f4cea33 | 107 | break; |
108 | ||
109 | case FIXED_CST: | |
645b0f8d | 110 | warnfmt = (expr |
111 | ? G_("fixed-point overflow in expression %qE of type %qT " | |
112 | "results in %qE") | |
113 | : G_("fixed-point overflow in expression of type %qT " | |
114 | "results in %qE")); | |
0f4cea33 | 115 | break; |
116 | ||
117 | case VECTOR_CST: | |
645b0f8d | 118 | warnfmt = (expr |
119 | ? G_("vector overflow in expression %qE of type %qT " | |
120 | "results in %qE") | |
121 | : G_("vector overflow in expression of type %qT " | |
122 | "results in %qE")); | |
0f4cea33 | 123 | break; |
124 | ||
125 | case COMPLEX_CST: | |
126 | if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST) | |
645b0f8d | 127 | warnfmt = (expr |
128 | ? G_("complex integer overflow in expression %qE " | |
129 | "of type %qT results in %qE") | |
130 | : G_("complex integer overflow in expression of type %qT " | |
131 | "results in %qE")); | |
0f4cea33 | 132 | else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST) |
645b0f8d | 133 | warnfmt = (expr |
134 | ? G_("complex floating point overflow in expression %qE " | |
135 | "of type %qT results in %qE") | |
136 | : G_("complex floating point overflow in expression " | |
137 | "of type %qT results in %qE")); | |
138 | else | |
139 | return; | |
0f4cea33 | 140 | break; |
141 | ||
142 | default: | |
645b0f8d | 143 | return; |
0f4cea33 | 144 | } |
645b0f8d | 145 | |
94a62c5a | 146 | bool warned; |
645b0f8d | 147 | if (expr) |
94a62c5a | 148 | warned = warning_at (loc, OPT_Woverflow, warnfmt, expr, TREE_TYPE (expr), |
149 | value); | |
645b0f8d | 150 | else |
94a62c5a | 151 | warned = warning_at (loc, OPT_Woverflow, warnfmt, TREE_TYPE (value), |
152 | value); | |
645b0f8d | 153 | |
94a62c5a | 154 | if (warned) |
155 | TREE_NO_WARNING (value) = 1; | |
0f4cea33 | 156 | } |
157 | ||
1a2d3e8e | 158 | /* Helper function for walk_tree. Unwrap C_MAYBE_CONST_EXPRs in an expression |
159 | pointed to by TP. */ | |
160 | ||
161 | static tree | |
162 | unwrap_c_maybe_const (tree *tp, int *walk_subtrees, void *) | |
163 | { | |
164 | if (TREE_CODE (*tp) == C_MAYBE_CONST_EXPR) | |
165 | { | |
166 | *tp = C_MAYBE_CONST_EXPR_EXPR (*tp); | |
167 | /* C_MAYBE_CONST_EXPRs don't nest. */ | |
168 | *walk_subtrees = false; | |
169 | } | |
170 | return NULL_TREE; | |
171 | } | |
172 | ||
0f4cea33 | 173 | /* Warn about uses of logical || / && operator in a context where it |
174 | is likely that the bitwise equivalent was intended by the | |
175 | programmer. We have seen an expression in which CODE is a binary | |
176 | operator used to combine expressions OP_LEFT and OP_RIGHT, which before folding | |
177 | had CODE_LEFT and CODE_RIGHT, into an expression of type TYPE. */ | |
178 | ||
179 | void | |
180 | warn_logical_operator (location_t location, enum tree_code code, tree type, | |
181 | enum tree_code code_left, tree op_left, | |
182 | enum tree_code ARG_UNUSED (code_right), tree op_right) | |
183 | { | |
184 | int or_op = (code == TRUTH_ORIF_EXPR || code == TRUTH_OR_EXPR); | |
185 | int in0_p, in1_p, in_p; | |
186 | tree low0, low1, low, high0, high1, high, lhs, rhs, tem; | |
187 | bool strict_overflow_p = false; | |
188 | ||
0526776f | 189 | if (!warn_logical_op) |
190 | return; | |
191 | ||
0f4cea33 | 192 | if (code != TRUTH_ANDIF_EXPR |
193 | && code != TRUTH_AND_EXPR | |
194 | && code != TRUTH_ORIF_EXPR | |
195 | && code != TRUTH_OR_EXPR) | |
196 | return; | |
197 | ||
198 | /* We don't want to warn if either operand comes from a macro | |
199 | expansion. ??? This doesn't work with e.g. NEGATE_EXPR yet; | |
200 | see PR61534. */ | |
201 | if (from_macro_expansion_at (EXPR_LOCATION (op_left)) | |
202 | || from_macro_expansion_at (EXPR_LOCATION (op_right))) | |
203 | return; | |
204 | ||
205 | /* Warn if &&/|| are being used in a context where it is | |
206 | likely that the bitwise equivalent was intended by the | |
207 | programmer. That is, an expression such as op && MASK | |
208 | where op should not be any boolean expression, nor a | |
209 | constant, and mask seems to be a non-boolean integer constant. */ | |
210 | if (TREE_CODE (op_right) == CONST_DECL) | |
211 | /* An enumerator counts as a constant. */ | |
212 | op_right = DECL_INITIAL (op_right); | |
213 | if (!truth_value_p (code_left) | |
214 | && INTEGRAL_TYPE_P (TREE_TYPE (op_left)) | |
215 | && !CONSTANT_CLASS_P (op_left) | |
d582d140 | 216 | && !TREE_NO_WARNING (op_left)) |
0f4cea33 | 217 | { |
d582d140 | 218 | tree folded_op_right = fold_for_warn (op_right); |
219 | if (TREE_CODE (folded_op_right) == INTEGER_CST | |
220 | && !integer_zerop (folded_op_right) | |
221 | && !integer_onep (folded_op_right)) | |
222 | { | |
94a62c5a | 223 | bool warned; |
d582d140 | 224 | if (or_op) |
94a62c5a | 225 | warned |
226 | = warning_at (location, OPT_Wlogical_op, | |
227 | "logical %<or%> applied to non-boolean constant"); | |
d582d140 | 228 | else |
94a62c5a | 229 | warned |
230 | = warning_at (location, OPT_Wlogical_op, | |
231 | "logical %<and%> applied to non-boolean constant"); | |
232 | if (warned) | |
233 | TREE_NO_WARNING (op_left) = true; | |
d582d140 | 234 | return; |
235 | } | |
0f4cea33 | 236 | } |
237 | ||
238 | /* We do not warn for constants because they are typical of macro | |
239 | expansions that test for features. */ | |
240 | if (CONSTANT_CLASS_P (fold_for_warn (op_left)) | |
241 | || CONSTANT_CLASS_P (fold_for_warn (op_right))) | |
242 | return; | |
243 | ||
244 | /* This warning only makes sense with logical operands. */ | |
245 | if (!(truth_value_p (TREE_CODE (op_left)) | |
246 | || INTEGRAL_TYPE_P (TREE_TYPE (op_left))) | |
247 | || !(truth_value_p (TREE_CODE (op_right)) | |
248 | || INTEGRAL_TYPE_P (TREE_TYPE (op_right)))) | |
249 | return; | |
250 | ||
251 | /* The range computations only work with scalars. */ | |
252 | if (VECTOR_TYPE_P (TREE_TYPE (op_left)) | |
253 | || VECTOR_TYPE_P (TREE_TYPE (op_right))) | |
254 | return; | |
255 | ||
256 | /* We first test whether either side separately is trivially true | |
257 | (with OR) or trivially false (with AND). If so, do not warn. | |
258 | This is a common idiom for testing ranges of data types in | |
259 | portable code. */ | |
1a2d3e8e | 260 | op_left = unshare_expr (op_left); |
261 | walk_tree_without_duplicates (&op_left, unwrap_c_maybe_const, NULL); | |
0f4cea33 | 262 | lhs = make_range (op_left, &in0_p, &low0, &high0, &strict_overflow_p); |
263 | if (!lhs) | |
264 | return; | |
0f4cea33 | 265 | |
266 | /* If this is an OR operation, invert both sides; now, the result | |
267 | should be always false to get a warning. */ | |
268 | if (or_op) | |
269 | in0_p = !in0_p; | |
270 | ||
271 | tem = build_range_check (UNKNOWN_LOCATION, type, lhs, in0_p, low0, high0); | |
272 | if (tem && integer_zerop (tem)) | |
273 | return; | |
274 | ||
1a2d3e8e | 275 | op_right = unshare_expr (op_right); |
276 | walk_tree_without_duplicates (&op_right, unwrap_c_maybe_const, NULL); | |
0f4cea33 | 277 | rhs = make_range (op_right, &in1_p, &low1, &high1, &strict_overflow_p); |
278 | if (!rhs) | |
279 | return; | |
0f4cea33 | 280 | |
281 | /* If this is an OR operation, invert both sides; now, the result | |
282 | should be always false to get a warning. */ | |
283 | if (or_op) | |
284 | in1_p = !in1_p; | |
285 | ||
286 | tem = build_range_check (UNKNOWN_LOCATION, type, rhs, in1_p, low1, high1); | |
287 | if (tem && integer_zerop (tem)) | |
288 | return; | |
289 | ||
290 | /* If both expressions have the same operand, if we can merge the | |
291 | ranges, ... */ | |
292 | if (operand_equal_p (lhs, rhs, 0) | |
293 | && merge_ranges (&in_p, &low, &high, in0_p, low0, high0, | |
294 | in1_p, low1, high1)) | |
295 | { | |
296 | tem = build_range_check (UNKNOWN_LOCATION, type, lhs, in_p, low, high); | |
297 | /* ... and if the range test is always false, then warn. */ | |
298 | if (tem && integer_zerop (tem)) | |
299 | { | |
300 | if (or_op) | |
301 | warning_at (location, OPT_Wlogical_op, | |
302 | "logical %<or%> of collectively exhaustive tests is " | |
303 | "always true"); | |
304 | else | |
305 | warning_at (location, OPT_Wlogical_op, | |
306 | "logical %<and%> of mutually exclusive tests is " | |
307 | "always false"); | |
308 | } | |
309 | /* Or warn if the operands have exactly the same range, e.g. | |
310 | A > 0 && A > 0. */ | |
311 | else if (tree_int_cst_equal (low0, low1) | |
312 | && tree_int_cst_equal (high0, high1)) | |
313 | { | |
314 | if (or_op) | |
315 | warning_at (location, OPT_Wlogical_op, | |
316 | "logical %<or%> of equal expressions"); | |
317 | else | |
318 | warning_at (location, OPT_Wlogical_op, | |
319 | "logical %<and%> of equal expressions"); | |
320 | } | |
321 | } | |
322 | } | |
323 | ||
324 | /* Helper function for warn_tautological_cmp. Look for ARRAY_REFs | |
325 | with constant indices. */ | |
326 | ||
327 | static tree | |
876d4bc9 | 328 | find_array_ref_with_const_idx_r (tree *expr_p, int *, void *) |
0f4cea33 | 329 | { |
330 | tree expr = *expr_p; | |
331 | ||
332 | if ((TREE_CODE (expr) == ARRAY_REF | |
333 | || TREE_CODE (expr) == ARRAY_RANGE_REF) | |
fbfc389d | 334 | && (TREE_CODE (fold_for_warn (TREE_OPERAND (expr, 1))) |
335 | == INTEGER_CST)) | |
876d4bc9 | 336 | return integer_type_node; |
0f4cea33 | 337 | |
338 | return NULL_TREE; | |
339 | } | |
340 | ||
45d3a9aa | 341 | /* Subroutine of warn_tautological_cmp. Warn about bitwise comparison |
342 | that always evaluate to true or false. LOC is the location of the | |
343 | ==/!= comparison specified by CODE; LHS and RHS are the usual operands | |
344 | of this comparison. */ | |
345 | ||
346 | static void | |
fbfc389d | 347 | warn_tautological_bitwise_comparison (const op_location_t &loc, tree_code code, |
45d3a9aa | 348 | tree lhs, tree rhs) |
349 | { | |
350 | if (code != EQ_EXPR && code != NE_EXPR) | |
351 | return; | |
352 | ||
353 | /* Extract the operands from e.g. (x & 8) == 4. */ | |
354 | tree bitop; | |
355 | tree cst; | |
d582d140 | 356 | tree stripped_lhs = tree_strip_any_location_wrapper (lhs); |
357 | tree stripped_rhs = tree_strip_any_location_wrapper (rhs); | |
45d3a9aa | 358 | if ((TREE_CODE (lhs) == BIT_AND_EXPR |
359 | || TREE_CODE (lhs) == BIT_IOR_EXPR) | |
d582d140 | 360 | && TREE_CODE (stripped_rhs) == INTEGER_CST) |
361 | bitop = lhs, cst = stripped_rhs; | |
45d3a9aa | 362 | else if ((TREE_CODE (rhs) == BIT_AND_EXPR |
363 | || TREE_CODE (rhs) == BIT_IOR_EXPR) | |
d582d140 | 364 | && TREE_CODE (stripped_lhs) == INTEGER_CST) |
365 | bitop = rhs, cst = stripped_lhs; | |
45d3a9aa | 366 | else |
367 | return; | |
368 | ||
369 | tree bitopcst; | |
d582d140 | 370 | tree bitop_op0 = fold_for_warn (TREE_OPERAND (bitop, 0)); |
371 | if (TREE_CODE (bitop_op0) == INTEGER_CST) | |
372 | bitopcst = bitop_op0; | |
373 | else { | |
374 | tree bitop_op1 = fold_for_warn (TREE_OPERAND (bitop, 1)); | |
375 | if (TREE_CODE (bitop_op1) == INTEGER_CST) | |
376 | bitopcst = bitop_op1; | |
377 | else | |
378 | return; | |
379 | } | |
45d3a9aa | 380 | |
cb7bca5f | 381 | /* Note that the two operands are from before the usual integer |
bc64d8a6 | 382 | conversions, so their types might not be the same. |
383 | Use the larger of the two precisions and ignore bits outside | |
384 | of that. */ | |
385 | int prec = MAX (TYPE_PRECISION (TREE_TYPE (cst)), | |
386 | TYPE_PRECISION (TREE_TYPE (bitopcst))); | |
387 | ||
8688bba9 | 388 | wide_int bitopcstw = wi::to_wide (bitopcst, prec); |
389 | wide_int cstw = wi::to_wide (cst, prec); | |
bc64d8a6 | 390 | |
391 | wide_int res; | |
45d3a9aa | 392 | if (TREE_CODE (bitop) == BIT_AND_EXPR) |
bc64d8a6 | 393 | res = bitopcstw & cstw; |
45d3a9aa | 394 | else |
bc64d8a6 | 395 | res = bitopcstw | cstw; |
45d3a9aa | 396 | |
397 | /* For BIT_AND only warn if (CST2 & CST1) != CST1, and | |
398 | for BIT_OR only if (CST2 | CST1) != CST1. */ | |
bc64d8a6 | 399 | if (res == cstw) |
45d3a9aa | 400 | return; |
401 | ||
fbfc389d | 402 | binary_op_rich_location richloc (loc, lhs, rhs, false); |
45d3a9aa | 403 | if (code == EQ_EXPR) |
fbfc389d | 404 | warning_at (&richloc, OPT_Wtautological_compare, |
45d3a9aa | 405 | "bitwise comparison always evaluates to false"); |
406 | else | |
fbfc389d | 407 | warning_at (&richloc, OPT_Wtautological_compare, |
45d3a9aa | 408 | "bitwise comparison always evaluates to true"); |
409 | } | |
410 | ||
98de922f | 411 | /* Given LOC from a macro expansion, return the map for the outermost |
412 | macro in the nest of expansions. */ | |
413 | ||
414 | static const line_map_macro * | |
415 | get_outermost_macro_expansion (location_t loc) | |
416 | { | |
417 | gcc_assert (from_macro_expansion_at (loc)); | |
418 | ||
419 | const line_map *map = linemap_lookup (line_table, loc); | |
420 | const line_map_macro *macro_map; | |
421 | do | |
422 | { | |
423 | macro_map = linemap_check_macro (map); | |
424 | loc = linemap_unwind_toward_expansion (line_table, loc, &map); | |
425 | } while (linemap_macro_expansion_map_p (map)); | |
426 | ||
427 | return macro_map; | |
428 | } | |
429 | ||
fbfc389d | 430 | /* Given LOC_A and LOC_B from macro expansions, return true if |
431 | they are "spelled the same" i.e. if they are both directly from | |
432 | expansion of the same non-function-like macro. */ | |
433 | ||
434 | static bool | |
435 | spelled_the_same_p (location_t loc_a, location_t loc_b) | |
436 | { | |
437 | gcc_assert (from_macro_expansion_at (loc_a)); | |
438 | gcc_assert (from_macro_expansion_at (loc_b)); | |
439 | ||
98de922f | 440 | const line_map_macro *map_a = get_outermost_macro_expansion (loc_a); |
441 | const line_map_macro *map_b = get_outermost_macro_expansion (loc_b); | |
fbfc389d | 442 | |
443 | if (map_a->macro == map_b->macro) | |
444 | if (!cpp_fun_like_macro_p (map_a->macro)) | |
445 | return true; | |
446 | ||
447 | return false; | |
448 | } | |
449 | ||
0f4cea33 | 450 | /* Warn if a self-comparison always evaluates to true or false. LOC |
451 | is the location of the comparison with code CODE, LHS and RHS are | |
452 | operands of the comparison. */ | |
453 | ||
454 | void | |
fbfc389d | 455 | warn_tautological_cmp (const op_location_t &loc, enum tree_code code, |
456 | tree lhs, tree rhs) | |
0f4cea33 | 457 | { |
458 | if (TREE_CODE_CLASS (code) != tcc_comparison) | |
459 | return; | |
460 | ||
461 | /* Don't warn for various macro expansions. */ | |
fbfc389d | 462 | if (from_macro_expansion_at (loc)) |
0f4cea33 | 463 | return; |
fbfc389d | 464 | bool lhs_in_macro = from_macro_expansion_at (EXPR_LOCATION (lhs)); |
465 | bool rhs_in_macro = from_macro_expansion_at (EXPR_LOCATION (rhs)); | |
466 | if (lhs_in_macro || rhs_in_macro) | |
467 | { | |
468 | /* Don't warn if exactly one is from a macro. */ | |
469 | if (!(lhs_in_macro && rhs_in_macro)) | |
470 | return; | |
471 | ||
472 | /* If both are in a macro, only warn if they're spelled the same. */ | |
473 | if (!spelled_the_same_p (EXPR_LOCATION (lhs), EXPR_LOCATION (rhs))) | |
474 | return; | |
475 | } | |
0f4cea33 | 476 | |
45d3a9aa | 477 | warn_tautological_bitwise_comparison (loc, code, lhs, rhs); |
478 | ||
0f4cea33 | 479 | /* We do not warn for constants because they are typical of macro |
480 | expansions that test for features, sizeof, and similar. */ | |
481 | if (CONSTANT_CLASS_P (fold_for_warn (lhs)) | |
482 | || CONSTANT_CLASS_P (fold_for_warn (rhs))) | |
483 | return; | |
484 | ||
485 | /* Don't warn for e.g. | |
486 | HOST_WIDE_INT n; | |
487 | ... | |
488 | if (n == (long) n) ... | |
489 | */ | |
490 | if ((CONVERT_EXPR_P (lhs) || TREE_CODE (lhs) == NON_LVALUE_EXPR) | |
491 | || (CONVERT_EXPR_P (rhs) || TREE_CODE (rhs) == NON_LVALUE_EXPR)) | |
492 | return; | |
493 | ||
494 | /* Don't warn if either LHS or RHS has an IEEE floating-point type. | |
495 | It could be a NaN, and NaN never compares equal to anything, even | |
496 | itself. */ | |
497 | if (FLOAT_TYPE_P (TREE_TYPE (lhs)) || FLOAT_TYPE_P (TREE_TYPE (rhs))) | |
498 | return; | |
499 | ||
500 | if (operand_equal_p (lhs, rhs, 0)) | |
501 | { | |
502 | /* Don't warn about array references with constant indices; | |
503 | these are likely to come from a macro. */ | |
876d4bc9 | 504 | if (walk_tree_without_duplicates (&lhs, find_array_ref_with_const_idx_r, |
505 | NULL)) | |
0f4cea33 | 506 | return; |
507 | const bool always_true = (code == EQ_EXPR || code == LE_EXPR | |
508 | || code == GE_EXPR || code == UNLE_EXPR | |
509 | || code == UNGE_EXPR || code == UNEQ_EXPR); | |
fbfc389d | 510 | binary_op_rich_location richloc (loc, lhs, rhs, false); |
0f4cea33 | 511 | if (always_true) |
fbfc389d | 512 | warning_at (&richloc, OPT_Wtautological_compare, |
0f4cea33 | 513 | "self-comparison always evaluates to true"); |
514 | else | |
fbfc389d | 515 | warning_at (&richloc, OPT_Wtautological_compare, |
0f4cea33 | 516 | "self-comparison always evaluates to false"); |
517 | } | |
518 | } | |
519 | ||
520 | /* Return true iff EXPR only contains boolean operands, or comparisons. */ | |
521 | ||
522 | static bool | |
523 | expr_has_boolean_operands_p (tree expr) | |
524 | { | |
525 | STRIP_NOPS (expr); | |
526 | ||
527 | if (CONVERT_EXPR_P (expr)) | |
528 | return bool_promoted_to_int_p (expr); | |
529 | else if (UNARY_CLASS_P (expr)) | |
530 | return expr_has_boolean_operands_p (TREE_OPERAND (expr, 0)); | |
531 | else if (BINARY_CLASS_P (expr)) | |
532 | return (expr_has_boolean_operands_p (TREE_OPERAND (expr, 0)) | |
533 | && expr_has_boolean_operands_p (TREE_OPERAND (expr, 1))); | |
534 | else if (COMPARISON_CLASS_P (expr)) | |
535 | return true; | |
536 | else | |
537 | return false; | |
538 | } | |
539 | ||
540 | /* Warn about logical not used on the left hand side operand of a comparison. | |
541 | This function assumes that the LHS is inside of TRUTH_NOT_EXPR. | |
542 | Do not warn if RHS is of a boolean type, a logical operator, or | |
543 | a comparison. */ | |
544 | ||
545 | void | |
546 | warn_logical_not_parentheses (location_t location, enum tree_code code, | |
547 | tree lhs, tree rhs) | |
548 | { | |
549 | if (TREE_CODE_CLASS (code) != tcc_comparison | |
550 | || TREE_TYPE (rhs) == NULL_TREE | |
551 | || TREE_CODE (TREE_TYPE (rhs)) == BOOLEAN_TYPE | |
552 | || truth_value_p (TREE_CODE (rhs))) | |
553 | return; | |
554 | ||
555 | /* Don't warn for expression like !x == ~(bool1 | bool2). */ | |
556 | if (expr_has_boolean_operands_p (rhs)) | |
557 | return; | |
558 | ||
559 | /* Don't warn for !x == 0 or !y != 0, those are equivalent to | |
560 | !(x == 0) or !(y != 0). */ | |
561 | if ((code == EQ_EXPR || code == NE_EXPR) | |
562 | && integer_zerop (rhs)) | |
563 | return; | |
564 | ||
bc35ef65 | 565 | auto_diagnostic_group d; |
0f4cea33 | 566 | if (warning_at (location, OPT_Wlogical_not_parentheses, |
567 | "logical not is only applied to the left hand side of " | |
568 | "comparison") | |
569 | && EXPR_HAS_LOCATION (lhs)) | |
570 | { | |
571 | location_t lhs_loc = EXPR_LOCATION (lhs); | |
572 | rich_location richloc (line_table, lhs_loc); | |
573 | richloc.add_fixit_insert_before (lhs_loc, "("); | |
574 | richloc.add_fixit_insert_after (lhs_loc, ")"); | |
3b6578b3 | 575 | inform (&richloc, "add parentheses around left hand side " |
576 | "expression to silence this warning"); | |
0f4cea33 | 577 | } |
578 | } | |
579 | ||
580 | /* Warn if EXP contains any computations whose results are not used. | |
581 | Return true if a warning is printed; false otherwise. LOCUS is the | |
582 | (potential) location of the expression. */ | |
583 | ||
584 | bool | |
585 | warn_if_unused_value (const_tree exp, location_t locus) | |
586 | { | |
587 | restart: | |
588 | if (TREE_USED (exp) || TREE_NO_WARNING (exp)) | |
589 | return false; | |
590 | ||
591 | /* Don't warn about void constructs. This includes casting to void, | |
592 | void function calls, and statement expressions with a final cast | |
593 | to void. */ | |
594 | if (VOID_TYPE_P (TREE_TYPE (exp))) | |
595 | return false; | |
596 | ||
597 | if (EXPR_HAS_LOCATION (exp)) | |
598 | locus = EXPR_LOCATION (exp); | |
599 | ||
600 | switch (TREE_CODE (exp)) | |
601 | { | |
602 | case PREINCREMENT_EXPR: | |
603 | case POSTINCREMENT_EXPR: | |
604 | case PREDECREMENT_EXPR: | |
605 | case POSTDECREMENT_EXPR: | |
606 | case MODIFY_EXPR: | |
607 | case INIT_EXPR: | |
608 | case TARGET_EXPR: | |
609 | case CALL_EXPR: | |
610 | case TRY_CATCH_EXPR: | |
0f4cea33 | 611 | case EXIT_EXPR: |
612 | case VA_ARG_EXPR: | |
613 | return false; | |
614 | ||
615 | case BIND_EXPR: | |
616 | /* For a binding, warn if no side effect within it. */ | |
617 | exp = BIND_EXPR_BODY (exp); | |
618 | goto restart; | |
619 | ||
620 | case SAVE_EXPR: | |
621 | case NON_LVALUE_EXPR: | |
622 | case NOP_EXPR: | |
623 | exp = TREE_OPERAND (exp, 0); | |
624 | goto restart; | |
625 | ||
626 | case TRUTH_ORIF_EXPR: | |
627 | case TRUTH_ANDIF_EXPR: | |
628 | /* In && or ||, warn if 2nd operand has no side effect. */ | |
629 | exp = TREE_OPERAND (exp, 1); | |
630 | goto restart; | |
631 | ||
632 | case COMPOUND_EXPR: | |
633 | if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus)) | |
634 | return true; | |
635 | /* Let people do `(foo (), 0)' without a warning. */ | |
636 | if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) | |
637 | return false; | |
638 | exp = TREE_OPERAND (exp, 1); | |
639 | goto restart; | |
640 | ||
641 | case COND_EXPR: | |
642 | /* If this is an expression with side effects, don't warn; this | |
643 | case commonly appears in macro expansions. */ | |
644 | if (TREE_SIDE_EFFECTS (exp)) | |
645 | return false; | |
646 | goto warn; | |
647 | ||
648 | case INDIRECT_REF: | |
649 | /* Don't warn about automatic dereferencing of references, since | |
650 | the user cannot control it. */ | |
651 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) | |
652 | { | |
653 | exp = TREE_OPERAND (exp, 0); | |
654 | goto restart; | |
655 | } | |
656 | /* Fall through. */ | |
657 | ||
658 | default: | |
659 | /* Referencing a volatile value is a side effect, so don't warn. */ | |
660 | if ((DECL_P (exp) || REFERENCE_CLASS_P (exp)) | |
661 | && TREE_THIS_VOLATILE (exp)) | |
662 | return false; | |
663 | ||
664 | /* If this is an expression which has no operands, there is no value | |
665 | to be unused. There are no such language-independent codes, | |
666 | but front ends may define such. */ | |
667 | if (EXPRESSION_CLASS_P (exp) && TREE_OPERAND_LENGTH (exp) == 0) | |
668 | return false; | |
669 | ||
670 | warn: | |
671 | return warning_at (locus, OPT_Wunused_value, "value computed is not used"); | |
672 | } | |
673 | } | |
674 | ||
d9757bb6 | 675 | /* Print a warning about casts that might indicate violation of strict |
676 | aliasing rules if -Wstrict-aliasing is used and strict aliasing | |
677 | mode is in effect. LOC is the location of the expression being | |
678 | cast, EXPR might be from inside it. TYPE is the type we're casting | |
679 | to. */ | |
0f4cea33 | 680 | |
681 | bool | |
d9757bb6 | 682 | strict_aliasing_warning (location_t loc, tree type, tree expr) |
0f4cea33 | 683 | { |
d9757bb6 | 684 | if (loc == UNKNOWN_LOCATION) |
685 | loc = input_location; | |
686 | ||
0f4cea33 | 687 | /* Strip pointer conversion chains and get to the correct original type. */ |
688 | STRIP_NOPS (expr); | |
d9757bb6 | 689 | tree otype = TREE_TYPE (expr); |
0f4cea33 | 690 | |
691 | if (!(flag_strict_aliasing | |
692 | && POINTER_TYPE_P (type) | |
693 | && POINTER_TYPE_P (otype) | |
694 | && !VOID_TYPE_P (TREE_TYPE (type))) | |
695 | /* If the type we are casting to is a ref-all pointer | |
696 | dereferencing it is always valid. */ | |
697 | || TYPE_REF_CAN_ALIAS_ALL (type)) | |
698 | return false; | |
699 | ||
700 | if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR | |
701 | && (DECL_P (TREE_OPERAND (expr, 0)) | |
702 | || handled_component_p (TREE_OPERAND (expr, 0)))) | |
703 | { | |
704 | /* Casting the address of an object to non void pointer. Warn | |
705 | if the cast breaks type based aliasing. */ | |
706 | if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2) | |
707 | { | |
d9757bb6 | 708 | warning_at (loc, OPT_Wstrict_aliasing, |
709 | "type-punning to incomplete type " | |
710 | "might break strict-aliasing rules"); | |
0f4cea33 | 711 | return true; |
712 | } | |
713 | else | |
714 | { | |
715 | /* warn_strict_aliasing >= 3. This includes the default (3). | |
716 | Only warn if the cast is dereferenced immediately. */ | |
717 | alias_set_type set1 | |
718 | = get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))); | |
719 | alias_set_type set2 = get_alias_set (TREE_TYPE (type)); | |
720 | ||
195b31a0 | 721 | if (set2 != 0 |
722 | && set1 != set2 | |
723 | && !alias_set_subset_of (set2, set1) | |
724 | && !alias_sets_conflict_p (set1, set2)) | |
0f4cea33 | 725 | { |
d9757bb6 | 726 | warning_at (loc, OPT_Wstrict_aliasing, |
727 | "dereferencing type-punned " | |
728 | "pointer will break strict-aliasing rules"); | |
0f4cea33 | 729 | return true; |
730 | } | |
731 | else if (warn_strict_aliasing == 2 | |
732 | && !alias_sets_must_conflict_p (set1, set2)) | |
733 | { | |
d9757bb6 | 734 | warning_at (loc, OPT_Wstrict_aliasing, |
735 | "dereferencing type-punned " | |
736 | "pointer might break strict-aliasing rules"); | |
0f4cea33 | 737 | return true; |
738 | } | |
739 | } | |
740 | } | |
741 | else if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype))) | |
742 | { | |
743 | /* At this level, warn for any conversions, even if an address is | |
744 | not taken in the same statement. This will likely produce many | |
745 | false positives, but could be useful to pinpoint problems that | |
746 | are not revealed at higher levels. */ | |
747 | alias_set_type set1 = get_alias_set (TREE_TYPE (otype)); | |
748 | alias_set_type set2 = get_alias_set (TREE_TYPE (type)); | |
8bbdcaf0 | 749 | if (!COMPLETE_TYPE_P (TREE_TYPE (type)) |
0f4cea33 | 750 | || !alias_sets_must_conflict_p (set1, set2)) |
751 | { | |
d9757bb6 | 752 | warning_at (loc, OPT_Wstrict_aliasing, |
753 | "dereferencing type-punned " | |
754 | "pointer might break strict-aliasing rules"); | |
0f4cea33 | 755 | return true; |
756 | } | |
757 | } | |
758 | ||
759 | return false; | |
760 | } | |
761 | ||
762 | /* Warn about memset (&a, 0, sizeof (&a)); and similar mistakes with | |
763 | sizeof as last operand of certain builtins. */ | |
764 | ||
765 | void | |
766 | sizeof_pointer_memaccess_warning (location_t *sizeof_arg_loc, tree callee, | |
767 | vec<tree, va_gc> *params, tree *sizeof_arg, | |
768 | bool (*comp_types) (tree, tree)) | |
769 | { | |
770 | tree type, dest = NULL_TREE, src = NULL_TREE, tem; | |
771 | bool strop = false, cmp = false; | |
772 | unsigned int idx = ~0; | |
773 | location_t loc; | |
774 | ||
775 | if (TREE_CODE (callee) != FUNCTION_DECL | |
a0e9bfbb | 776 | || !fndecl_built_in_p (callee, BUILT_IN_NORMAL) |
0f4cea33 | 777 | || vec_safe_length (params) <= 1) |
778 | return; | |
779 | ||
d8aad786 | 780 | enum built_in_function fncode = DECL_FUNCTION_CODE (callee); |
781 | switch (fncode) | |
0f4cea33 | 782 | { |
783 | case BUILT_IN_STRNCMP: | |
784 | case BUILT_IN_STRNCASECMP: | |
785 | cmp = true; | |
786 | /* FALLTHRU */ | |
787 | case BUILT_IN_STRNCPY: | |
788 | case BUILT_IN_STRNCPY_CHK: | |
789 | case BUILT_IN_STRNCAT: | |
790 | case BUILT_IN_STRNCAT_CHK: | |
791 | case BUILT_IN_STPNCPY: | |
792 | case BUILT_IN_STPNCPY_CHK: | |
793 | strop = true; | |
794 | /* FALLTHRU */ | |
795 | case BUILT_IN_MEMCPY: | |
796 | case BUILT_IN_MEMCPY_CHK: | |
797 | case BUILT_IN_MEMMOVE: | |
798 | case BUILT_IN_MEMMOVE_CHK: | |
799 | if (params->length () < 3) | |
800 | return; | |
801 | src = (*params)[1]; | |
802 | dest = (*params)[0]; | |
803 | idx = 2; | |
804 | break; | |
805 | case BUILT_IN_BCOPY: | |
806 | if (params->length () < 3) | |
807 | return; | |
808 | src = (*params)[0]; | |
809 | dest = (*params)[1]; | |
810 | idx = 2; | |
811 | break; | |
812 | case BUILT_IN_MEMCMP: | |
813 | case BUILT_IN_BCMP: | |
814 | if (params->length () < 3) | |
815 | return; | |
816 | src = (*params)[1]; | |
817 | dest = (*params)[0]; | |
818 | idx = 2; | |
819 | cmp = true; | |
820 | break; | |
821 | case BUILT_IN_MEMSET: | |
822 | case BUILT_IN_MEMSET_CHK: | |
823 | if (params->length () < 3) | |
824 | return; | |
825 | dest = (*params)[0]; | |
826 | idx = 2; | |
827 | break; | |
828 | case BUILT_IN_BZERO: | |
829 | dest = (*params)[0]; | |
830 | idx = 1; | |
831 | break; | |
832 | case BUILT_IN_STRNDUP: | |
833 | src = (*params)[0]; | |
834 | strop = true; | |
835 | idx = 1; | |
836 | break; | |
837 | case BUILT_IN_MEMCHR: | |
838 | if (params->length () < 3) | |
839 | return; | |
840 | src = (*params)[0]; | |
841 | idx = 2; | |
842 | break; | |
843 | case BUILT_IN_SNPRINTF: | |
844 | case BUILT_IN_SNPRINTF_CHK: | |
845 | case BUILT_IN_VSNPRINTF: | |
846 | case BUILT_IN_VSNPRINTF_CHK: | |
847 | dest = (*params)[0]; | |
848 | idx = 1; | |
849 | strop = true; | |
850 | break; | |
851 | default: | |
852 | break; | |
853 | } | |
854 | ||
855 | if (idx >= 3) | |
856 | return; | |
857 | ||
656f8801 | 858 | /* Use error_operand_p to detect non-error arguments with an error |
859 | type that the C++ front-end constructs. */ | |
860 | if (error_operand_p (src) | |
861 | || error_operand_p (dest) | |
862 | || !sizeof_arg[idx] | |
863 | || error_operand_p (sizeof_arg[idx])) | |
0f4cea33 | 864 | return; |
865 | ||
866 | type = TYPE_P (sizeof_arg[idx]) | |
867 | ? sizeof_arg[idx] : TREE_TYPE (sizeof_arg[idx]); | |
d8aad786 | 868 | |
0f4cea33 | 869 | if (!POINTER_TYPE_P (type)) |
d8aad786 | 870 | { |
871 | /* The argument type may be an array. Diagnose bounded string | |
872 | copy functions that specify the bound in terms of the source | |
2b691a1c | 873 | argument rather than the destination unless they are equal |
874 | to one another. Handle constant sizes and also try to handle | |
875 | sizeof expressions involving VLAs. */ | |
d8aad786 | 876 | if (strop && !cmp && fncode != BUILT_IN_STRNDUP && src) |
877 | { | |
878 | tem = tree_strip_nop_conversions (src); | |
879 | if (TREE_CODE (tem) == ADDR_EXPR) | |
880 | tem = TREE_OPERAND (tem, 0); | |
2b691a1c | 881 | |
0eff2551 | 882 | /* Avoid diagnosing sizeof SRC when SRC is declared with |
883 | attribute nonstring. */ | |
884 | tree dummy; | |
885 | if (get_attr_nonstring_decl (tem, &dummy)) | |
886 | return; | |
887 | ||
2b691a1c | 888 | tree d = tree_strip_nop_conversions (dest); |
889 | if (TREE_CODE (d) == ADDR_EXPR) | |
890 | d = TREE_OPERAND (d, 0); | |
891 | ||
892 | tree dstsz = TYPE_SIZE_UNIT (TREE_TYPE (d)); | |
893 | tree srcsz = TYPE_SIZE_UNIT (TREE_TYPE (tem)); | |
894 | ||
895 | if ((!dstsz | |
896 | || !srcsz | |
897 | || !operand_equal_p (dstsz, srcsz, OEP_LEXICOGRAPHIC)) | |
898 | && operand_equal_p (tem, sizeof_arg[idx], OEP_ADDRESS_OF)) | |
d8aad786 | 899 | warning_at (sizeof_arg_loc[idx], OPT_Wsizeof_pointer_memaccess, |
900 | "argument to %<sizeof%> in %qD call is the same " | |
901 | "expression as the source; did you mean to use " | |
902 | "the size of the destination?", | |
903 | callee); | |
904 | } | |
905 | ||
906 | return; | |
907 | } | |
0f4cea33 | 908 | |
909 | if (dest | |
910 | && (tem = tree_strip_nop_conversions (dest)) | |
911 | && POINTER_TYPE_P (TREE_TYPE (tem)) | |
912 | && comp_types (TREE_TYPE (TREE_TYPE (tem)), type)) | |
913 | return; | |
914 | ||
915 | if (src | |
916 | && (tem = tree_strip_nop_conversions (src)) | |
917 | && POINTER_TYPE_P (TREE_TYPE (tem)) | |
918 | && comp_types (TREE_TYPE (TREE_TYPE (tem)), type)) | |
919 | return; | |
920 | ||
921 | loc = sizeof_arg_loc[idx]; | |
922 | ||
923 | if (dest && !cmp) | |
924 | { | |
925 | if (!TYPE_P (sizeof_arg[idx]) | |
926 | && operand_equal_p (dest, sizeof_arg[idx], 0) | |
927 | && comp_types (TREE_TYPE (dest), type)) | |
928 | { | |
929 | if (TREE_CODE (sizeof_arg[idx]) == ADDR_EXPR && !strop) | |
930 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
931 | "argument to %<sizeof%> in %qD call is the same " | |
932 | "expression as the destination; did you mean to " | |
933 | "remove the addressof?", callee); | |
934 | else if ((TYPE_PRECISION (TREE_TYPE (type)) | |
935 | == TYPE_PRECISION (char_type_node)) | |
936 | || strop) | |
937 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
938 | "argument to %<sizeof%> in %qD call is the same " | |
939 | "expression as the destination; did you mean to " | |
940 | "provide an explicit length?", callee); | |
941 | else | |
942 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
943 | "argument to %<sizeof%> in %qD call is the same " | |
944 | "expression as the destination; did you mean to " | |
945 | "dereference it?", callee); | |
946 | return; | |
947 | } | |
948 | ||
949 | if (POINTER_TYPE_P (TREE_TYPE (dest)) | |
950 | && !strop | |
951 | && comp_types (TREE_TYPE (dest), type) | |
952 | && !VOID_TYPE_P (TREE_TYPE (type))) | |
953 | { | |
954 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
955 | "argument to %<sizeof%> in %qD call is the same " | |
956 | "pointer type %qT as the destination; expected %qT " | |
957 | "or an explicit length", callee, TREE_TYPE (dest), | |
958 | TREE_TYPE (TREE_TYPE (dest))); | |
959 | return; | |
960 | } | |
961 | } | |
962 | ||
963 | if (src && !cmp) | |
964 | { | |
965 | if (!TYPE_P (sizeof_arg[idx]) | |
966 | && operand_equal_p (src, sizeof_arg[idx], 0) | |
967 | && comp_types (TREE_TYPE (src), type)) | |
968 | { | |
969 | if (TREE_CODE (sizeof_arg[idx]) == ADDR_EXPR && !strop) | |
970 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
971 | "argument to %<sizeof%> in %qD call is the same " | |
972 | "expression as the source; did you mean to " | |
973 | "remove the addressof?", callee); | |
974 | else if ((TYPE_PRECISION (TREE_TYPE (type)) | |
975 | == TYPE_PRECISION (char_type_node)) | |
976 | || strop) | |
977 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
978 | "argument to %<sizeof%> in %qD call is the same " | |
979 | "expression as the source; did you mean to " | |
980 | "provide an explicit length?", callee); | |
981 | else | |
982 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
983 | "argument to %<sizeof%> in %qD call is the same " | |
984 | "expression as the source; did you mean to " | |
985 | "dereference it?", callee); | |
986 | return; | |
987 | } | |
988 | ||
989 | if (POINTER_TYPE_P (TREE_TYPE (src)) | |
990 | && !strop | |
991 | && comp_types (TREE_TYPE (src), type) | |
992 | && !VOID_TYPE_P (TREE_TYPE (type))) | |
993 | { | |
994 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
995 | "argument to %<sizeof%> in %qD call is the same " | |
996 | "pointer type %qT as the source; expected %qT " | |
997 | "or an explicit length", callee, TREE_TYPE (src), | |
998 | TREE_TYPE (TREE_TYPE (src))); | |
999 | return; | |
1000 | } | |
1001 | } | |
1002 | ||
1003 | if (dest) | |
1004 | { | |
1005 | if (!TYPE_P (sizeof_arg[idx]) | |
1006 | && operand_equal_p (dest, sizeof_arg[idx], 0) | |
1007 | && comp_types (TREE_TYPE (dest), type)) | |
1008 | { | |
1009 | if (TREE_CODE (sizeof_arg[idx]) == ADDR_EXPR && !strop) | |
1010 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1011 | "argument to %<sizeof%> in %qD call is the same " | |
1012 | "expression as the first source; did you mean to " | |
1013 | "remove the addressof?", callee); | |
1014 | else if ((TYPE_PRECISION (TREE_TYPE (type)) | |
1015 | == TYPE_PRECISION (char_type_node)) | |
1016 | || strop) | |
1017 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1018 | "argument to %<sizeof%> in %qD call is the same " | |
1019 | "expression as the first source; did you mean to " | |
1020 | "provide an explicit length?", callee); | |
1021 | else | |
1022 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1023 | "argument to %<sizeof%> in %qD call is the same " | |
1024 | "expression as the first source; did you mean to " | |
1025 | "dereference it?", callee); | |
1026 | return; | |
1027 | } | |
1028 | ||
1029 | if (POINTER_TYPE_P (TREE_TYPE (dest)) | |
1030 | && !strop | |
1031 | && comp_types (TREE_TYPE (dest), type) | |
1032 | && !VOID_TYPE_P (TREE_TYPE (type))) | |
1033 | { | |
1034 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1035 | "argument to %<sizeof%> in %qD call is the same " | |
1036 | "pointer type %qT as the first source; expected %qT " | |
1037 | "or an explicit length", callee, TREE_TYPE (dest), | |
1038 | TREE_TYPE (TREE_TYPE (dest))); | |
1039 | return; | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | if (src) | |
1044 | { | |
1045 | if (!TYPE_P (sizeof_arg[idx]) | |
1046 | && operand_equal_p (src, sizeof_arg[idx], 0) | |
1047 | && comp_types (TREE_TYPE (src), type)) | |
1048 | { | |
1049 | if (TREE_CODE (sizeof_arg[idx]) == ADDR_EXPR && !strop) | |
1050 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1051 | "argument to %<sizeof%> in %qD call is the same " | |
1052 | "expression as the second source; did you mean to " | |
1053 | "remove the addressof?", callee); | |
1054 | else if ((TYPE_PRECISION (TREE_TYPE (type)) | |
1055 | == TYPE_PRECISION (char_type_node)) | |
1056 | || strop) | |
1057 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1058 | "argument to %<sizeof%> in %qD call is the same " | |
1059 | "expression as the second source; did you mean to " | |
1060 | "provide an explicit length?", callee); | |
1061 | else | |
1062 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1063 | "argument to %<sizeof%> in %qD call is the same " | |
1064 | "expression as the second source; did you mean to " | |
1065 | "dereference it?", callee); | |
1066 | return; | |
1067 | } | |
1068 | ||
1069 | if (POINTER_TYPE_P (TREE_TYPE (src)) | |
1070 | && !strop | |
1071 | && comp_types (TREE_TYPE (src), type) | |
1072 | && !VOID_TYPE_P (TREE_TYPE (type))) | |
1073 | { | |
1074 | warning_at (loc, OPT_Wsizeof_pointer_memaccess, | |
1075 | "argument to %<sizeof%> in %qD call is the same " | |
1076 | "pointer type %qT as the second source; expected %qT " | |
1077 | "or an explicit length", callee, TREE_TYPE (src), | |
1078 | TREE_TYPE (TREE_TYPE (src))); | |
1079 | return; | |
1080 | } | |
1081 | } | |
1082 | ||
1083 | } | |
1084 | ||
1085 | /* Warn for unlikely, improbable, or stupid DECL declarations | |
1086 | of `main'. */ | |
1087 | ||
1088 | void | |
1089 | check_main_parameter_types (tree decl) | |
1090 | { | |
1091 | function_args_iterator iter; | |
1092 | tree type; | |
1093 | int argct = 0; | |
1094 | ||
1095 | FOREACH_FUNCTION_ARGS (TREE_TYPE (decl), type, iter) | |
1096 | { | |
1097 | /* XXX void_type_node belies the abstraction. */ | |
1098 | if (type == void_type_node || type == error_mark_node) | |
1099 | break; | |
1100 | ||
1101 | tree t = type; | |
1102 | if (TYPE_ATOMIC (t)) | |
1103 | pedwarn (input_location, OPT_Wmain, | |
1104 | "%<_Atomic%>-qualified parameter type %qT of %q+D", | |
1105 | type, decl); | |
1106 | while (POINTER_TYPE_P (t)) | |
1107 | { | |
1108 | t = TREE_TYPE (t); | |
1109 | if (TYPE_ATOMIC (t)) | |
1110 | pedwarn (input_location, OPT_Wmain, | |
1111 | "%<_Atomic%>-qualified parameter type %qT of %q+D", | |
1112 | type, decl); | |
1113 | } | |
1114 | ||
1115 | ++argct; | |
1116 | switch (argct) | |
1117 | { | |
1118 | case 1: | |
1119 | if (TYPE_MAIN_VARIANT (type) != integer_type_node) | |
1120 | pedwarn (input_location, OPT_Wmain, | |
1121 | "first argument of %q+D should be %<int%>", decl); | |
1122 | break; | |
1123 | ||
1124 | case 2: | |
1125 | if (TREE_CODE (type) != POINTER_TYPE | |
1126 | || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE | |
1127 | || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) | |
1128 | != char_type_node)) | |
1129 | pedwarn (input_location, OPT_Wmain, | |
1130 | "second argument of %q+D should be %<char **%>", decl); | |
1131 | break; | |
1132 | ||
1133 | case 3: | |
1134 | if (TREE_CODE (type) != POINTER_TYPE | |
1135 | || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE | |
1136 | || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type))) | |
1137 | != char_type_node)) | |
1138 | pedwarn (input_location, OPT_Wmain, | |
1139 | "third argument of %q+D should probably be " | |
1140 | "%<char **%>", decl); | |
1141 | break; | |
1142 | } | |
1143 | } | |
1144 | ||
1145 | /* It is intentional that this message does not mention the third | |
1146 | argument because it's only mentioned in an appendix of the | |
1147 | standard. */ | |
1148 | if (argct > 0 && (argct < 2 || argct > 3)) | |
1149 | pedwarn (input_location, OPT_Wmain, | |
1150 | "%q+D takes only zero or two arguments", decl); | |
1151 | ||
1152 | if (stdarg_p (TREE_TYPE (decl))) | |
1153 | pedwarn (input_location, OPT_Wmain, | |
1154 | "%q+D declared as variadic function", decl); | |
1155 | } | |
1156 | ||
1157 | /* Warns if the conversion of EXPR to TYPE may alter a value. | |
1158 | This is a helper function for warnings_for_convert_and_check. */ | |
1159 | ||
1160 | static void | |
645b0f8d | 1161 | conversion_warning (location_t loc, tree type, tree expr, tree result) |
0f4cea33 | 1162 | { |
1163 | tree expr_type = TREE_TYPE (expr); | |
1164 | enum conversion_safety conversion_kind; | |
1165 | ||
1166 | if (!warn_conversion && !warn_sign_conversion && !warn_float_conversion) | |
1167 | return; | |
1168 | ||
1169 | /* This may happen, because for LHS op= RHS we preevaluate | |
1170 | RHS and create C_MAYBE_CONST_EXPR <SAVE_EXPR <RHS>>, which | |
1171 | means we could no longer see the code of the EXPR. */ | |
1172 | if (TREE_CODE (expr) == C_MAYBE_CONST_EXPR) | |
1173 | expr = C_MAYBE_CONST_EXPR_EXPR (expr); | |
1174 | if (TREE_CODE (expr) == SAVE_EXPR) | |
1175 | expr = TREE_OPERAND (expr, 0); | |
1176 | ||
1177 | switch (TREE_CODE (expr)) | |
1178 | { | |
1179 | case EQ_EXPR: | |
1180 | case NE_EXPR: | |
1181 | case LE_EXPR: | |
1182 | case GE_EXPR: | |
1183 | case LT_EXPR: | |
1184 | case GT_EXPR: | |
1185 | case TRUTH_ANDIF_EXPR: | |
1186 | case TRUTH_ORIF_EXPR: | |
1187 | case TRUTH_AND_EXPR: | |
1188 | case TRUTH_OR_EXPR: | |
1189 | case TRUTH_XOR_EXPR: | |
1190 | case TRUTH_NOT_EXPR: | |
1191 | /* Conversion from boolean to a signed:1 bit-field (which only | |
1192 | can hold the values 0 and -1) doesn't lose information - but | |
1193 | it does change the value. */ | |
1194 | if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type)) | |
1195 | warning_at (loc, OPT_Wconversion, | |
1196 | "conversion to %qT from boolean expression", type); | |
1197 | return; | |
1198 | ||
1199 | case REAL_CST: | |
1200 | case INTEGER_CST: | |
1201 | case COMPLEX_CST: | |
645b0f8d | 1202 | { |
1203 | conversion_kind = unsafe_conversion_p (loc, type, expr, result, true); | |
1204 | int warnopt; | |
1205 | if (conversion_kind == UNSAFE_REAL) | |
1206 | warnopt = OPT_Wfloat_conversion; | |
1207 | else if (conversion_kind) | |
1208 | warnopt = OPT_Wconversion; | |
1209 | else | |
1210 | break; | |
0f4cea33 | 1211 | |
645b0f8d | 1212 | if (TREE_CODE_CLASS (TREE_CODE (result)) == tcc_constant) |
1213 | warning_at (loc, warnopt, | |
1214 | "conversion from %qT to %qT changes value from %qE to %qE", | |
1215 | expr_type, type, expr, result); | |
1216 | else | |
1217 | warning_at (loc, warnopt, | |
1218 | "conversion from %qT to %qT changes the value of %qE", | |
1219 | expr_type, type, expr); | |
1220 | break; | |
1221 | } | |
0f4cea33 | 1222 | case COND_EXPR: |
645b0f8d | 1223 | { |
0f4cea33 | 1224 | /* In case of COND_EXPR, we do not care about the type of |
1225 | COND_EXPR, only about the conversion of each operand. */ | |
1226 | tree op1 = TREE_OPERAND (expr, 1); | |
1227 | tree op2 = TREE_OPERAND (expr, 2); | |
1228 | ||
645b0f8d | 1229 | conversion_warning (loc, type, op1, result); |
1230 | conversion_warning (loc, type, op2, result); | |
0f4cea33 | 1231 | return; |
1232 | } | |
1233 | ||
1234 | default: /* 'expr' is not a constant. */ | |
645b0f8d | 1235 | conversion_kind = unsafe_conversion_p (loc, type, expr, result, true); |
1236 | if (conversion_kind == UNSAFE_IMAGINARY) | |
0f4cea33 | 1237 | warning_at (loc, OPT_Wconversion, |
f9936b7c | 1238 | "conversion from %qT to %qT discards imaginary component", |
645b0f8d | 1239 | expr_type, type); |
a977cac9 | 1240 | else |
1241 | { | |
1242 | int warnopt; | |
1243 | if (conversion_kind == UNSAFE_REAL) | |
1244 | warnopt = OPT_Wfloat_conversion; | |
1245 | else if (conversion_kind) | |
1246 | warnopt = OPT_Wconversion; | |
1247 | else | |
1248 | break; | |
1249 | warning_at (loc, warnopt, | |
1250 | "conversion from %qT to %qT may change value", | |
1251 | expr_type, type); | |
1252 | } | |
0f4cea33 | 1253 | } |
1254 | } | |
1255 | ||
1256 | /* Produce warnings after a conversion. RESULT is the result of | |
1257 | converting EXPR to TYPE. This is a helper function for | |
1258 | convert_and_check and cp_convert_and_check. */ | |
1259 | ||
1260 | void | |
1261 | warnings_for_convert_and_check (location_t loc, tree type, tree expr, | |
1262 | tree result) | |
1263 | { | |
1264 | loc = expansion_point_location_if_in_system_header (loc); | |
1265 | ||
645b0f8d | 1266 | bool cst = TREE_CODE_CLASS (TREE_CODE (result)) == tcc_constant; |
1267 | ||
1268 | tree exprtype = TREE_TYPE (expr); | |
1269 | ||
0f4cea33 | 1270 | if (TREE_CODE (expr) == INTEGER_CST |
1271 | && (TREE_CODE (type) == INTEGER_TYPE | |
1272 | || TREE_CODE (type) == ENUMERAL_TYPE) | |
1273 | && !int_fits_type_p (expr, type)) | |
1274 | { | |
1275 | /* Do not diagnose overflow in a constant expression merely | |
1276 | because a conversion overflowed. */ | |
1277 | if (TREE_OVERFLOW (result)) | |
1278 | TREE_OVERFLOW (result) = TREE_OVERFLOW (expr); | |
1279 | ||
1280 | if (TYPE_UNSIGNED (type)) | |
1281 | { | |
1282 | /* This detects cases like converting -129 or 256 to | |
1283 | unsigned char. */ | |
1284 | if (!int_fits_type_p (expr, c_common_signed_type (type))) | |
645b0f8d | 1285 | { |
1286 | if (cst) | |
1287 | warning_at (loc, OPT_Woverflow, | |
1288 | (TYPE_UNSIGNED (exprtype) | |
1289 | ? G_("conversion from %qT to %qT " | |
1290 | "changes value from %qE to %qE") | |
1291 | : G_("unsigned conversion from %qT to %qT " | |
1292 | "changes value from %qE to %qE")), | |
1293 | exprtype, type, expr, result); | |
1294 | else | |
1295 | warning_at (loc, OPT_Woverflow, | |
1296 | (TYPE_UNSIGNED (exprtype) | |
1297 | ? G_("conversion from %qT to %qT " | |
1298 | "changes the value of %qE") | |
1299 | : G_("unsigned conversion from %qT to %qT " | |
1300 | "changes the value of %qE")), | |
1301 | exprtype, type, expr); | |
1302 | } | |
0f4cea33 | 1303 | else |
645b0f8d | 1304 | conversion_warning (loc, type, expr, result); |
0f4cea33 | 1305 | } |
1306 | else if (!int_fits_type_p (expr, c_common_unsigned_type (type))) | |
645b0f8d | 1307 | { |
1308 | if (cst) | |
1309 | warning_at (loc, OPT_Woverflow, | |
1310 | "overflow in conversion from %qT to %qT " | |
1311 | "changes value from %qE to %qE", | |
1312 | exprtype, type, expr, result); | |
1313 | else | |
1314 | warning_at (loc, OPT_Woverflow, | |
1315 | "overflow in conversion from %qT to %qT " | |
1316 | "changes the value of %qE", | |
1317 | exprtype, type, expr); | |
1318 | } | |
0f4cea33 | 1319 | /* No warning for converting 0x80000000 to int. */ |
1320 | else if (pedantic | |
645b0f8d | 1321 | && (TREE_CODE (exprtype) != INTEGER_TYPE |
1322 | || TYPE_PRECISION (exprtype) | |
0f4cea33 | 1323 | != TYPE_PRECISION (type))) |
645b0f8d | 1324 | { |
1325 | if (cst) | |
1326 | warning_at (loc, OPT_Woverflow, | |
1327 | "overflow in conversion from %qT to %qT " | |
1328 | "changes value from %qE to %qE", | |
1329 | exprtype, type, expr, result); | |
1330 | else | |
1331 | warning_at (loc, OPT_Woverflow, | |
1332 | "overflow in conversion from %qT to %qT " | |
1333 | "changes the value of %qE", | |
1334 | exprtype, type, expr); | |
1335 | } | |
0f4cea33 | 1336 | else |
645b0f8d | 1337 | conversion_warning (loc, type, expr, result); |
0f4cea33 | 1338 | } |
1339 | else if ((TREE_CODE (result) == INTEGER_CST | |
1340 | || TREE_CODE (result) == FIXED_CST) && TREE_OVERFLOW (result)) | |
645b0f8d | 1341 | { |
1342 | if (cst) | |
1343 | warning_at (loc, OPT_Woverflow, | |
1344 | "overflow in conversion from %qT to %qT " | |
0f637402 | 1345 | "changes value from %qE to %qE", |
645b0f8d | 1346 | exprtype, type, expr, result); |
1347 | else | |
1348 | warning_at (loc, OPT_Woverflow, | |
1349 | "overflow in conversion from %qT to %qT " | |
0f637402 | 1350 | "changes the value of %qE", |
645b0f8d | 1351 | exprtype, type, expr); |
1352 | } | |
0f4cea33 | 1353 | else |
645b0f8d | 1354 | conversion_warning (loc, type, expr, result); |
0f4cea33 | 1355 | } |
1356 | ||
1357 | /* Subroutines of c_do_switch_warnings, called via splay_tree_foreach. | |
1358 | Used to verify that case values match up with enumerator values. */ | |
1359 | ||
1360 | static void | |
1361 | match_case_to_enum_1 (tree key, tree type, tree label) | |
1362 | { | |
65fb3b5b | 1363 | /* Avoid warning about enums that have no enumerators. */ |
1364 | if (TYPE_VALUES (type) == NULL_TREE) | |
1365 | return; | |
1366 | ||
0f4cea33 | 1367 | char buf[WIDE_INT_PRINT_BUFFER_SIZE]; |
1368 | ||
1369 | if (tree_fits_uhwi_p (key)) | |
e3d0f65c | 1370 | print_dec (wi::to_wide (key), buf, UNSIGNED); |
0f4cea33 | 1371 | else if (tree_fits_shwi_p (key)) |
e3d0f65c | 1372 | print_dec (wi::to_wide (key), buf, SIGNED); |
0f4cea33 | 1373 | else |
e3d0f65c | 1374 | print_hex (wi::to_wide (key), buf); |
0f4cea33 | 1375 | |
72749341 | 1376 | if (TYPE_NAME (type) == NULL_TREE) |
0f4cea33 | 1377 | warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)), |
1378 | warn_switch ? OPT_Wswitch : OPT_Wswitch_enum, | |
1379 | "case value %qs not in enumerated type", | |
1380 | buf); | |
1381 | else | |
1382 | warning_at (DECL_SOURCE_LOCATION (CASE_LABEL (label)), | |
1383 | warn_switch ? OPT_Wswitch : OPT_Wswitch_enum, | |
1384 | "case value %qs not in enumerated type %qT", | |
1385 | buf, type); | |
1386 | } | |
1387 | ||
1388 | /* Subroutine of c_do_switch_warnings, called via splay_tree_foreach. | |
1389 | Used to verify that case values match up with enumerator values. */ | |
1390 | ||
1391 | static int | |
1392 | match_case_to_enum (splay_tree_node node, void *data) | |
1393 | { | |
1394 | tree label = (tree) node->value; | |
1395 | tree type = (tree) data; | |
1396 | ||
1397 | /* Skip default case. */ | |
1398 | if (!CASE_LOW (label)) | |
1399 | return 0; | |
1400 | ||
1401 | /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear | |
1402 | when we did our enum->case scan. Reset our scratch bit after. */ | |
1403 | if (!CASE_LOW_SEEN (label)) | |
1404 | match_case_to_enum_1 (CASE_LOW (label), type, label); | |
1405 | else | |
1406 | CASE_LOW_SEEN (label) = 0; | |
1407 | ||
1408 | /* If CASE_HIGH is non-null, we have a range. If CASE_HIGH_SEEN is | |
1409 | not set, that means that CASE_HIGH did not appear when we did our | |
1410 | enum->case scan. Reset our scratch bit after. */ | |
1411 | if (CASE_HIGH (label)) | |
1412 | { | |
1413 | if (!CASE_HIGH_SEEN (label)) | |
1414 | match_case_to_enum_1 (CASE_HIGH (label), type, label); | |
1415 | else | |
1416 | CASE_HIGH_SEEN (label) = 0; | |
1417 | } | |
1418 | ||
1419 | return 0; | |
1420 | } | |
1421 | ||
1422 | /* Handle -Wswitch*. Called from the front end after parsing the | |
1423 | switch construct. */ | |
1424 | /* ??? Should probably be somewhere generic, since other languages | |
1425 | besides C and C++ would want this. At the moment, however, C/C++ | |
1426 | are the only tree-ssa languages that support enumerations at all, | |
1427 | so the point is moot. */ | |
1428 | ||
1429 | void | |
1430 | c_do_switch_warnings (splay_tree cases, location_t switch_location, | |
45cf699c | 1431 | tree type, tree cond, bool bool_cond_p) |
0f4cea33 | 1432 | { |
1433 | splay_tree_node default_node; | |
1434 | splay_tree_node node; | |
1435 | tree chain; | |
45cf699c | 1436 | bool outside_range_p = false; |
1437 | ||
1438 | if (type != error_mark_node | |
1439 | && type != TREE_TYPE (cond) | |
1440 | && INTEGRAL_TYPE_P (type) | |
1441 | && INTEGRAL_TYPE_P (TREE_TYPE (cond)) | |
1442 | && (!tree_int_cst_equal (TYPE_MIN_VALUE (type), | |
1443 | TYPE_MIN_VALUE (TREE_TYPE (cond))) | |
1444 | || !tree_int_cst_equal (TYPE_MAX_VALUE (type), | |
1445 | TYPE_MAX_VALUE (TREE_TYPE (cond))))) | |
1446 | { | |
1447 | tree min_value = TYPE_MIN_VALUE (type); | |
1448 | tree max_value = TYPE_MAX_VALUE (type); | |
1449 | ||
1450 | node = splay_tree_predecessor (cases, (splay_tree_key) min_value); | |
1451 | if (node && node->key) | |
1452 | { | |
1453 | outside_range_p = true; | |
1454 | /* There is at least one case smaller than TYPE's minimum value. | |
1455 | NODE itself could be still a range overlapping the valid values, | |
1456 | but any predecessors thereof except the default case will be | |
1457 | completely outside of range. */ | |
1458 | if (CASE_HIGH ((tree) node->value) | |
1459 | && tree_int_cst_compare (CASE_HIGH ((tree) node->value), | |
1460 | min_value) >= 0) | |
1461 | { | |
1462 | location_t loc = EXPR_LOCATION ((tree) node->value); | |
1463 | warning_at (loc, 0, "lower value in case label range" | |
1464 | " less than minimum value for type"); | |
1465 | CASE_LOW ((tree) node->value) = convert (TREE_TYPE (cond), | |
1466 | min_value); | |
1467 | node->key = (splay_tree_key) CASE_LOW ((tree) node->value); | |
1468 | } | |
1469 | /* All the following ones are completely outside of range. */ | |
1470 | do | |
1471 | { | |
1472 | node = splay_tree_predecessor (cases, | |
1473 | (splay_tree_key) min_value); | |
1474 | if (node == NULL || !node->key) | |
1475 | break; | |
1476 | location_t loc = EXPR_LOCATION ((tree) node->value); | |
1477 | warning_at (loc, 0, "case label value is less than minimum " | |
1478 | "value for type"); | |
1479 | splay_tree_remove (cases, node->key); | |
1480 | } | |
1481 | while (1); | |
1482 | } | |
1483 | node = splay_tree_lookup (cases, (splay_tree_key) max_value); | |
1484 | if (node == NULL) | |
1485 | node = splay_tree_predecessor (cases, (splay_tree_key) max_value); | |
1486 | /* Handle a single node that might partially overlap the range. */ | |
1487 | if (node | |
1488 | && node->key | |
1489 | && CASE_HIGH ((tree) node->value) | |
1490 | && tree_int_cst_compare (CASE_HIGH ((tree) node->value), | |
1491 | max_value) > 0) | |
1492 | { | |
1493 | location_t loc = EXPR_LOCATION ((tree) node->value); | |
1494 | warning_at (loc, 0, "upper value in case label range" | |
1495 | " exceeds maximum value for type"); | |
1496 | CASE_HIGH ((tree) node->value) | |
1497 | = convert (TREE_TYPE (cond), max_value); | |
1498 | outside_range_p = true; | |
1499 | } | |
1500 | /* And any nodes that are completely outside of the range. */ | |
1501 | while ((node = splay_tree_successor (cases, | |
1502 | (splay_tree_key) max_value)) | |
1503 | != NULL) | |
1504 | { | |
1505 | location_t loc = EXPR_LOCATION ((tree) node->value); | |
1506 | warning_at (loc, 0, | |
1507 | "case label value exceeds maximum value for type"); | |
1508 | splay_tree_remove (cases, node->key); | |
1509 | outside_range_p = true; | |
1510 | } | |
1511 | } | |
0f4cea33 | 1512 | |
1513 | if (!warn_switch && !warn_switch_enum && !warn_switch_default | |
1514 | && !warn_switch_bool) | |
1515 | return; | |
1516 | ||
1517 | default_node = splay_tree_lookup (cases, (splay_tree_key) NULL); | |
1518 | if (!default_node) | |
1519 | warning_at (switch_location, OPT_Wswitch_default, | |
1520 | "switch missing default case"); | |
1521 | ||
1522 | /* There are certain cases where -Wswitch-bool warnings aren't | |
1523 | desirable, such as | |
1524 | switch (boolean) | |
1525 | { | |
1526 | case true: ... | |
1527 | case false: ... | |
1528 | } | |
1529 | so be careful here. */ | |
1530 | if (warn_switch_bool && bool_cond_p) | |
1531 | { | |
1532 | splay_tree_node min_node; | |
1533 | /* If there's a default node, it's also the value with the minimal | |
1534 | key. So look at the penultimate key (if any). */ | |
1535 | if (default_node) | |
1536 | min_node = splay_tree_successor (cases, (splay_tree_key) NULL); | |
1537 | else | |
1538 | min_node = splay_tree_min (cases); | |
1539 | tree min = min_node ? (tree) min_node->key : NULL_TREE; | |
1540 | ||
1541 | splay_tree_node max_node = splay_tree_max (cases); | |
1542 | /* This might be a case range, so look at the value with the | |
1543 | maximal key and then check CASE_HIGH. */ | |
1544 | tree max = max_node ? (tree) max_node->value : NULL_TREE; | |
1545 | if (max) | |
1546 | max = CASE_HIGH (max) ? CASE_HIGH (max) : CASE_LOW (max); | |
1547 | ||
1548 | /* If there's a case value > 1 or < 0, that is outside bool | |
1549 | range, warn. */ | |
1550 | if (outside_range_p | |
e3d0f65c | 1551 | || (max && wi::gts_p (wi::to_wide (max), 1)) |
1552 | || (min && wi::lts_p (wi::to_wide (min), 0)) | |
0f4cea33 | 1553 | /* And handle the |
1554 | switch (boolean) | |
1555 | { | |
1556 | case true: ... | |
1557 | case false: ... | |
1558 | default: ... | |
1559 | } | |
1560 | case, where we want to warn. */ | |
1561 | || (default_node | |
e3d0f65c | 1562 | && max && wi::to_wide (max) == 1 |
1563 | && min && wi::to_wide (min) == 0)) | |
0f4cea33 | 1564 | warning_at (switch_location, OPT_Wswitch_bool, |
1565 | "switch condition has boolean value"); | |
1566 | } | |
1567 | ||
1568 | /* From here on, we only care about enumerated types. */ | |
1569 | if (!type || TREE_CODE (type) != ENUMERAL_TYPE) | |
1570 | return; | |
1571 | ||
1572 | /* From here on, we only care about -Wswitch and -Wswitch-enum. */ | |
1573 | if (!warn_switch_enum && !warn_switch) | |
1574 | return; | |
1575 | ||
1576 | /* Check the cases. Warn about case values which are not members of | |
1577 | the enumerated type. For -Wswitch-enum, or for -Wswitch when | |
1578 | there is no default case, check that exactly all enumeration | |
1579 | literals are covered by the cases. */ | |
1580 | ||
1581 | /* Clearing COND if it is not an integer constant simplifies | |
1582 | the tests inside the loop below. */ | |
1583 | if (TREE_CODE (cond) != INTEGER_CST) | |
1584 | cond = NULL_TREE; | |
1585 | ||
1586 | /* The time complexity here is O(N*lg(N)) worst case, but for the | |
1587 | common case of monotonically increasing enumerators, it is | |
1588 | O(N), since the nature of the splay tree will keep the next | |
1589 | element adjacent to the root at all times. */ | |
1590 | ||
1591 | for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain)) | |
1592 | { | |
1593 | tree value = TREE_VALUE (chain); | |
1594 | if (TREE_CODE (value) == CONST_DECL) | |
1595 | value = DECL_INITIAL (value); | |
1596 | node = splay_tree_lookup (cases, (splay_tree_key) value); | |
1597 | if (node) | |
1598 | { | |
1599 | /* Mark the CASE_LOW part of the case entry as seen. */ | |
1600 | tree label = (tree) node->value; | |
1601 | CASE_LOW_SEEN (label) = 1; | |
1602 | continue; | |
1603 | } | |
1604 | ||
1605 | /* Even though there wasn't an exact match, there might be a | |
1606 | case range which includes the enumerator's value. */ | |
1607 | node = splay_tree_predecessor (cases, (splay_tree_key) value); | |
1608 | if (node && CASE_HIGH ((tree) node->value)) | |
1609 | { | |
1610 | tree label = (tree) node->value; | |
1611 | int cmp = tree_int_cst_compare (CASE_HIGH (label), value); | |
1612 | if (cmp >= 0) | |
1613 | { | |
1614 | /* If we match the upper bound exactly, mark the CASE_HIGH | |
1615 | part of the case entry as seen. */ | |
1616 | if (cmp == 0) | |
1617 | CASE_HIGH_SEEN (label) = 1; | |
1618 | continue; | |
1619 | } | |
1620 | } | |
1621 | ||
1622 | /* We've now determined that this enumerated literal isn't | |
1623 | handled by the case labels of the switch statement. */ | |
1624 | ||
1625 | /* If the switch expression is a constant, we only really care | |
1626 | about whether that constant is handled by the switch. */ | |
1627 | if (cond && tree_int_cst_compare (cond, value)) | |
1628 | continue; | |
1629 | ||
1630 | /* If there is a default_node, the only relevant option is | |
1631 | Wswitch-enum. Otherwise, if both are enabled then we prefer | |
1632 | to warn using -Wswitch because -Wswitch is enabled by -Wall | |
1633 | while -Wswitch-enum is explicit. */ | |
1634 | warning_at (switch_location, | |
1635 | (default_node || !warn_switch | |
1636 | ? OPT_Wswitch_enum | |
1637 | : OPT_Wswitch), | |
1638 | "enumeration value %qE not handled in switch", | |
1639 | TREE_PURPOSE (chain)); | |
1640 | } | |
1641 | ||
1642 | /* Warn if there are case expressions that don't correspond to | |
1643 | enumerators. This can occur since C and C++ don't enforce | |
1644 | type-checking of assignments to enumeration variables. | |
1645 | ||
1646 | The time complexity here is now always O(N) worst case, since | |
1647 | we should have marked both the lower bound and upper bound of | |
1648 | every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN | |
1649 | above. This scan also resets those fields. */ | |
1650 | ||
1651 | splay_tree_foreach (cases, match_case_to_enum, type); | |
1652 | } | |
1653 | ||
1654 | /* Warn for A ?: C expressions (with B omitted) where A is a boolean | |
1655 | expression, because B will always be true. */ | |
1656 | ||
1657 | void | |
1658 | warn_for_omitted_condop (location_t location, tree cond) | |
1659 | { | |
1660 | /* In C++ template declarations it can happen that the type is dependent | |
1661 | and not yet known, thus TREE_TYPE (cond) == NULL_TREE. */ | |
1662 | if (truth_value_p (TREE_CODE (cond)) | |
1663 | || (TREE_TYPE (cond) != NULL_TREE | |
1664 | && TREE_CODE (TREE_TYPE (cond)) == BOOLEAN_TYPE)) | |
1665 | warning_at (location, OPT_Wparentheses, | |
85b9be9b | 1666 | "the omitted middle operand in %<?:%> will always be %<true%>, " |
0f4cea33 | 1667 | "suggest explicit middle operand"); |
1668 | } | |
1669 | ||
1670 | /* Give an error for storing into ARG, which is 'const'. USE indicates | |
1671 | how ARG was being used. */ | |
1672 | ||
1673 | void | |
1674 | readonly_error (location_t loc, tree arg, enum lvalue_use use) | |
1675 | { | |
1676 | gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement | |
1677 | || use == lv_asm); | |
d582d140 | 1678 | STRIP_ANY_LOCATION_WRAPPER (arg); |
0f4cea33 | 1679 | /* Using this macro rather than (for example) arrays of messages |
1680 | ensures that all the format strings are checked at compile | |
1681 | time. */ | |
1682 | #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \ | |
1683 | : (use == lv_increment ? (I) \ | |
1684 | : (use == lv_decrement ? (D) : (AS)))) | |
1685 | if (TREE_CODE (arg) == COMPONENT_REF) | |
1686 | { | |
1687 | if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) | |
1688 | error_at (loc, READONLY_MSG (G_("assignment of member " | |
1689 | "%qD in read-only object"), | |
1690 | G_("increment of member " | |
1691 | "%qD in read-only object"), | |
1692 | G_("decrement of member " | |
1693 | "%qD in read-only object"), | |
1694 | G_("member %qD in read-only object " | |
1695 | "used as %<asm%> output")), | |
1696 | TREE_OPERAND (arg, 1)); | |
1697 | else | |
1698 | error_at (loc, READONLY_MSG (G_("assignment of read-only member %qD"), | |
1699 | G_("increment of read-only member %qD"), | |
1700 | G_("decrement of read-only member %qD"), | |
1701 | G_("read-only member %qD used as %<asm%> output")), | |
1702 | TREE_OPERAND (arg, 1)); | |
1703 | } | |
1704 | else if (VAR_P (arg)) | |
1705 | error_at (loc, READONLY_MSG (G_("assignment of read-only variable %qD"), | |
1706 | G_("increment of read-only variable %qD"), | |
1707 | G_("decrement of read-only variable %qD"), | |
1708 | G_("read-only variable %qD used as %<asm%> output")), | |
1709 | arg); | |
1710 | else if (TREE_CODE (arg) == PARM_DECL) | |
1711 | error_at (loc, READONLY_MSG (G_("assignment of read-only parameter %qD"), | |
1712 | G_("increment of read-only parameter %qD"), | |
1713 | G_("decrement of read-only parameter %qD"), | |
1714 | G_("read-only parameter %qD use as %<asm%> output")), | |
1715 | arg); | |
1716 | else if (TREE_CODE (arg) == RESULT_DECL) | |
1717 | { | |
1718 | gcc_assert (c_dialect_cxx ()); | |
1719 | error_at (loc, READONLY_MSG (G_("assignment of " | |
1720 | "read-only named return value %qD"), | |
1721 | G_("increment of " | |
1722 | "read-only named return value %qD"), | |
1723 | G_("decrement of " | |
1724 | "read-only named return value %qD"), | |
1725 | G_("read-only named return value %qD " | |
1726 | "used as %<asm%>output")), | |
1727 | arg); | |
1728 | } | |
1729 | else if (TREE_CODE (arg) == FUNCTION_DECL) | |
1730 | error_at (loc, READONLY_MSG (G_("assignment of function %qD"), | |
1731 | G_("increment of function %qD"), | |
1732 | G_("decrement of function %qD"), | |
1733 | G_("function %qD used as %<asm%> output")), | |
1734 | arg); | |
1735 | else | |
1736 | error_at (loc, READONLY_MSG (G_("assignment of read-only location %qE"), | |
1737 | G_("increment of read-only location %qE"), | |
1738 | G_("decrement of read-only location %qE"), | |
1739 | G_("read-only location %qE used as %<asm%> output")), | |
1740 | arg); | |
1741 | } | |
1742 | ||
1743 | /* Print an error message for an invalid lvalue. USE says | |
1744 | how the lvalue is being used and so selects the error message. LOC | |
1745 | is the location for the error. */ | |
1746 | ||
1747 | void | |
1748 | lvalue_error (location_t loc, enum lvalue_use use) | |
1749 | { | |
1750 | switch (use) | |
1751 | { | |
1752 | case lv_assign: | |
1753 | error_at (loc, "lvalue required as left operand of assignment"); | |
1754 | break; | |
1755 | case lv_increment: | |
1756 | error_at (loc, "lvalue required as increment operand"); | |
1757 | break; | |
1758 | case lv_decrement: | |
1759 | error_at (loc, "lvalue required as decrement operand"); | |
1760 | break; | |
1761 | case lv_addressof: | |
1762 | error_at (loc, "lvalue required as unary %<&%> operand"); | |
1763 | break; | |
1764 | case lv_asm: | |
85b9be9b | 1765 | error_at (loc, "lvalue required in %<asm%> statement"); |
0f4cea33 | 1766 | break; |
1767 | default: | |
1768 | gcc_unreachable (); | |
1769 | } | |
1770 | } | |
1771 | ||
1772 | /* Print an error message for an invalid indirection of type TYPE. | |
1773 | ERRSTRING is the name of the operator for the indirection. */ | |
1774 | ||
1775 | void | |
1776 | invalid_indirection_error (location_t loc, tree type, ref_operator errstring) | |
1777 | { | |
1778 | switch (errstring) | |
1779 | { | |
1780 | case RO_NULL: | |
1781 | gcc_assert (c_dialect_cxx ()); | |
1782 | error_at (loc, "invalid type argument (have %qT)", type); | |
1783 | break; | |
1784 | case RO_ARRAY_INDEXING: | |
1785 | error_at (loc, | |
1786 | "invalid type argument of array indexing (have %qT)", | |
1787 | type); | |
1788 | break; | |
1789 | case RO_UNARY_STAR: | |
1790 | error_at (loc, | |
1791 | "invalid type argument of unary %<*%> (have %qT)", | |
1792 | type); | |
1793 | break; | |
1794 | case RO_ARROW: | |
1795 | error_at (loc, | |
1796 | "invalid type argument of %<->%> (have %qT)", | |
1797 | type); | |
1798 | break; | |
1799 | case RO_ARROW_STAR: | |
1800 | error_at (loc, | |
1801 | "invalid type argument of %<->*%> (have %qT)", | |
1802 | type); | |
1803 | break; | |
1804 | case RO_IMPLICIT_CONVERSION: | |
1805 | error_at (loc, | |
1806 | "invalid type argument of implicit conversion (have %qT)", | |
1807 | type); | |
1808 | break; | |
1809 | default: | |
1810 | gcc_unreachable (); | |
1811 | } | |
1812 | } | |
1813 | ||
1814 | /* Subscripting with type char is likely to lose on a machine where | |
1815 | chars are signed. So warn on any machine, but optionally. Don't | |
1816 | warn for unsigned char since that type is safe. Don't warn for | |
1817 | signed char because anyone who uses that must have done so | |
1818 | deliberately. Furthermore, we reduce the false positive load by | |
d582d140 | 1819 | warning only for non-constant value of type char. |
1820 | LOC is the location of the subscripting expression. */ | |
0f4cea33 | 1821 | |
1822 | void | |
1823 | warn_array_subscript_with_type_char (location_t loc, tree index) | |
1824 | { | |
d582d140 | 1825 | if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node) |
1826 | { | |
1827 | /* If INDEX has a location, use it; otherwise use LOC (the location | |
1828 | of the subscripting expression as a whole). */ | |
1829 | loc = EXPR_LOC_OR_LOC (index, loc); | |
1830 | STRIP_ANY_LOCATION_WRAPPER (index); | |
1831 | if (TREE_CODE (index) != INTEGER_CST) | |
1832 | warning_at (loc, OPT_Wchar_subscripts, | |
1833 | "array subscript has type %<char%>"); | |
1834 | } | |
0f4cea33 | 1835 | } |
1836 | ||
1837 | /* Implement -Wparentheses for the unexpected C precedence rules, to | |
1838 | cover cases like x + y << z which readers are likely to | |
1839 | misinterpret. We have seen an expression in which CODE is a binary | |
1840 | operator used to combine expressions ARG_LEFT and ARG_RIGHT, which | |
1841 | before folding had CODE_LEFT and CODE_RIGHT. CODE_LEFT and | |
1842 | CODE_RIGHT may be ERROR_MARK, which means that that side of the | |
1843 | expression was not formed using a binary or unary operator, or it | |
1844 | was enclosed in parentheses. */ | |
1845 | ||
1846 | void | |
1847 | warn_about_parentheses (location_t loc, enum tree_code code, | |
1848 | enum tree_code code_left, tree arg_left, | |
1849 | enum tree_code code_right, tree arg_right) | |
1850 | { | |
1851 | if (!warn_parentheses) | |
1852 | return; | |
1853 | ||
1854 | /* This macro tests that the expression ARG with original tree code | |
1855 | CODE appears to be a boolean expression. or the result of folding a | |
1856 | boolean expression. */ | |
1857 | #define APPEARS_TO_BE_BOOLEAN_EXPR_P(CODE, ARG) \ | |
1858 | (truth_value_p (TREE_CODE (ARG)) \ | |
1859 | || TREE_CODE (TREE_TYPE (ARG)) == BOOLEAN_TYPE \ | |
1860 | /* Folding may create 0 or 1 integers from other expressions. */ \ | |
1861 | || ((CODE) != INTEGER_CST \ | |
1862 | && (integer_onep (ARG) || integer_zerop (ARG)))) | |
1863 | ||
1864 | switch (code) | |
1865 | { | |
1866 | case LSHIFT_EXPR: | |
1867 | if (code_left == PLUS_EXPR) | |
1868 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1869 | "suggest parentheses around %<+%> inside %<<<%>"); | |
1870 | else if (code_right == PLUS_EXPR) | |
1871 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1872 | "suggest parentheses around %<+%> inside %<<<%>"); | |
1873 | else if (code_left == MINUS_EXPR) | |
1874 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1875 | "suggest parentheses around %<-%> inside %<<<%>"); | |
1876 | else if (code_right == MINUS_EXPR) | |
1877 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1878 | "suggest parentheses around %<-%> inside %<<<%>"); | |
1879 | return; | |
1880 | ||
1881 | case RSHIFT_EXPR: | |
1882 | if (code_left == PLUS_EXPR) | |
1883 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1884 | "suggest parentheses around %<+%> inside %<>>%>"); | |
1885 | else if (code_right == PLUS_EXPR) | |
1886 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1887 | "suggest parentheses around %<+%> inside %<>>%>"); | |
1888 | else if (code_left == MINUS_EXPR) | |
1889 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1890 | "suggest parentheses around %<-%> inside %<>>%>"); | |
1891 | else if (code_right == MINUS_EXPR) | |
1892 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1893 | "suggest parentheses around %<-%> inside %<>>%>"); | |
1894 | return; | |
1895 | ||
1896 | case TRUTH_ORIF_EXPR: | |
1897 | if (code_left == TRUTH_ANDIF_EXPR) | |
1898 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1899 | "suggest parentheses around %<&&%> within %<||%>"); | |
1900 | else if (code_right == TRUTH_ANDIF_EXPR) | |
1901 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1902 | "suggest parentheses around %<&&%> within %<||%>"); | |
1903 | return; | |
1904 | ||
1905 | case BIT_IOR_EXPR: | |
1906 | if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR | |
1907 | || code_left == PLUS_EXPR || code_left == MINUS_EXPR) | |
1908 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1909 | "suggest parentheses around arithmetic in operand of %<|%>"); | |
1910 | else if (code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR | |
1911 | || code_right == PLUS_EXPR || code_right == MINUS_EXPR) | |
1912 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1913 | "suggest parentheses around arithmetic in operand of %<|%>"); | |
1914 | /* Check cases like x|y==z */ | |
1915 | else if (TREE_CODE_CLASS (code_left) == tcc_comparison) | |
1916 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1917 | "suggest parentheses around comparison in operand of %<|%>"); | |
1918 | else if (TREE_CODE_CLASS (code_right) == tcc_comparison) | |
1919 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1920 | "suggest parentheses around comparison in operand of %<|%>"); | |
1921 | /* Check cases like !x | y */ | |
1922 | else if (code_left == TRUTH_NOT_EXPR | |
1923 | && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right)) | |
1924 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1925 | "suggest parentheses around operand of " | |
1926 | "%<!%> or change %<|%> to %<||%> or %<!%> to %<~%>"); | |
1927 | return; | |
1928 | ||
1929 | case BIT_XOR_EXPR: | |
1930 | if (code_left == BIT_AND_EXPR | |
1931 | || code_left == PLUS_EXPR || code_left == MINUS_EXPR) | |
1932 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1933 | "suggest parentheses around arithmetic in operand of %<^%>"); | |
1934 | else if (code_right == BIT_AND_EXPR | |
1935 | || code_right == PLUS_EXPR || code_right == MINUS_EXPR) | |
1936 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1937 | "suggest parentheses around arithmetic in operand of %<^%>"); | |
1938 | /* Check cases like x^y==z */ | |
1939 | else if (TREE_CODE_CLASS (code_left) == tcc_comparison) | |
1940 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1941 | "suggest parentheses around comparison in operand of %<^%>"); | |
1942 | else if (TREE_CODE_CLASS (code_right) == tcc_comparison) | |
1943 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1944 | "suggest parentheses around comparison in operand of %<^%>"); | |
1945 | return; | |
1946 | ||
1947 | case BIT_AND_EXPR: | |
1948 | if (code_left == PLUS_EXPR) | |
1949 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1950 | "suggest parentheses around %<+%> in operand of %<&%>"); | |
1951 | else if (code_right == PLUS_EXPR) | |
1952 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1953 | "suggest parentheses around %<+%> in operand of %<&%>"); | |
1954 | else if (code_left == MINUS_EXPR) | |
1955 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1956 | "suggest parentheses around %<-%> in operand of %<&%>"); | |
1957 | else if (code_right == MINUS_EXPR) | |
1958 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1959 | "suggest parentheses around %<-%> in operand of %<&%>"); | |
1960 | /* Check cases like x&y==z */ | |
1961 | else if (TREE_CODE_CLASS (code_left) == tcc_comparison) | |
1962 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1963 | "suggest parentheses around comparison in operand of %<&%>"); | |
1964 | else if (TREE_CODE_CLASS (code_right) == tcc_comparison) | |
1965 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1966 | "suggest parentheses around comparison in operand of %<&%>"); | |
1967 | /* Check cases like !x & y */ | |
1968 | else if (code_left == TRUTH_NOT_EXPR | |
1969 | && !APPEARS_TO_BE_BOOLEAN_EXPR_P (code_right, arg_right)) | |
1970 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1971 | "suggest parentheses around operand of " | |
1972 | "%<!%> or change %<&%> to %<&&%> or %<!%> to %<~%>"); | |
1973 | return; | |
1974 | ||
1975 | case EQ_EXPR: | |
1976 | if (TREE_CODE_CLASS (code_left) == tcc_comparison) | |
1977 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1978 | "suggest parentheses around comparison in operand of %<==%>"); | |
1979 | else if (TREE_CODE_CLASS (code_right) == tcc_comparison) | |
1980 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1981 | "suggest parentheses around comparison in operand of %<==%>"); | |
1982 | return; | |
1983 | case NE_EXPR: | |
1984 | if (TREE_CODE_CLASS (code_left) == tcc_comparison) | |
1985 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1986 | "suggest parentheses around comparison in operand of %<!=%>"); | |
1987 | else if (TREE_CODE_CLASS (code_right) == tcc_comparison) | |
1988 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
1989 | "suggest parentheses around comparison in operand of %<!=%>"); | |
1990 | return; | |
1991 | ||
1992 | default: | |
1993 | if (TREE_CODE_CLASS (code) == tcc_comparison) | |
1994 | { | |
1995 | if (TREE_CODE_CLASS (code_left) == tcc_comparison | |
1996 | && code_left != NE_EXPR && code_left != EQ_EXPR | |
1997 | && INTEGRAL_TYPE_P (TREE_TYPE (arg_left))) | |
1998 | warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses, | |
1999 | "comparisons like %<X<=Y<=Z%> do not " | |
2000 | "have their mathematical meaning"); | |
2001 | else if (TREE_CODE_CLASS (code_right) == tcc_comparison | |
2002 | && code_right != NE_EXPR && code_right != EQ_EXPR | |
2003 | && INTEGRAL_TYPE_P (TREE_TYPE (arg_right))) | |
2004 | warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses, | |
2005 | "comparisons like %<X<=Y<=Z%> do not " | |
2006 | "have their mathematical meaning"); | |
2007 | } | |
2008 | return; | |
2009 | } | |
2010 | #undef NOT_A_BOOLEAN_EXPR_P | |
2011 | } | |
2012 | ||
2013 | /* If LABEL (a LABEL_DECL) has not been used, issue a warning. */ | |
2014 | ||
2015 | void | |
2016 | warn_for_unused_label (tree label) | |
2017 | { | |
2018 | if (!TREE_USED (label)) | |
2019 | { | |
2020 | if (DECL_INITIAL (label)) | |
2021 | warning (OPT_Wunused_label, "label %q+D defined but not used", label); | |
2022 | else | |
2023 | warning (OPT_Wunused_label, "label %q+D declared but not defined", label); | |
2024 | } | |
629b6abc | 2025 | else if (asan_sanitize_use_after_scope ()) |
2026 | { | |
2027 | if (asan_used_labels == NULL) | |
2028 | asan_used_labels = new hash_set<tree> (16); | |
2029 | ||
2030 | asan_used_labels->add (label); | |
2031 | } | |
0f4cea33 | 2032 | } |
2033 | ||
2034 | /* Warn for division by zero according to the value of DIVISOR. LOC | |
2035 | is the location of the division operator. */ | |
2036 | ||
2037 | void | |
2038 | warn_for_div_by_zero (location_t loc, tree divisor) | |
2039 | { | |
2040 | /* If DIVISOR is zero, and has integral or fixed-point type, issue a warning | |
2041 | about division by zero. Do not issue a warning if DIVISOR has a | |
2042 | floating-point type, since we consider 0.0/0.0 a valid way of | |
2043 | generating a NaN. */ | |
2044 | if (c_inhibit_evaluation_warnings == 0 | |
2045 | && (integer_zerop (divisor) || fixed_zerop (divisor))) | |
2046 | warning_at (loc, OPT_Wdiv_by_zero, "division by zero"); | |
2047 | } | |
2048 | ||
2049 | /* Warn for patterns where memset appears to be used incorrectly. The | |
2050 | warning location should be LOC. ARG0, and ARG2 are the first and | |
2051 | last arguments to the call, while LITERAL_ZERO_MASK has a 1 bit for | |
2052 | each argument that was a literal zero. */ | |
2053 | ||
2054 | void | |
2055 | warn_for_memset (location_t loc, tree arg0, tree arg2, | |
2056 | int literal_zero_mask) | |
2057 | { | |
d76863c8 | 2058 | arg0 = fold_for_warn (arg0); |
2059 | arg2 = fold_for_warn (arg2); | |
2060 | ||
0f4cea33 | 2061 | if (warn_memset_transposed_args |
2062 | && integer_zerop (arg2) | |
2063 | && (literal_zero_mask & (1 << 2)) != 0 | |
2064 | && (literal_zero_mask & (1 << 1)) == 0) | |
2065 | warning_at (loc, OPT_Wmemset_transposed_args, | |
2066 | "%<memset%> used with constant zero length " | |
2067 | "parameter; this could be due to transposed " | |
2068 | "parameters"); | |
2069 | ||
2070 | if (warn_memset_elt_size && TREE_CODE (arg2) == INTEGER_CST) | |
2071 | { | |
2072 | STRIP_NOPS (arg0); | |
2073 | if (TREE_CODE (arg0) == ADDR_EXPR) | |
2074 | arg0 = TREE_OPERAND (arg0, 0); | |
2075 | tree type = TREE_TYPE (arg0); | |
2076 | if (type != NULL_TREE && TREE_CODE (type) == ARRAY_TYPE) | |
2077 | { | |
2078 | tree elt_type = TREE_TYPE (type); | |
2079 | tree domain = TYPE_DOMAIN (type); | |
dd38bee9 | 2080 | if (COMPLETE_TYPE_P (elt_type) |
2081 | && !integer_onep (TYPE_SIZE_UNIT (elt_type)) | |
0f4cea33 | 2082 | && domain != NULL_TREE |
a8de6c92 | 2083 | && TYPE_MAX_VALUE (domain) |
2084 | && TYPE_MIN_VALUE (domain) | |
2085 | && integer_zerop (TYPE_MIN_VALUE (domain)) | |
0f4cea33 | 2086 | && integer_onep (fold_build2 (MINUS_EXPR, domain, |
2087 | arg2, | |
a8de6c92 | 2088 | TYPE_MAX_VALUE (domain)))) |
0f4cea33 | 2089 | warning_at (loc, OPT_Wmemset_elt_size, |
2090 | "%<memset%> used with length equal to " | |
2091 | "number of elements without multiplication " | |
2092 | "by element size"); | |
2093 | } | |
2094 | } | |
2095 | } | |
2096 | ||
2097 | /* Subroutine of build_binary_op. Give warnings for comparisons | |
2098 | between signed and unsigned quantities that may fail. Do the | |
2099 | checking based on the original operand trees ORIG_OP0 and ORIG_OP1, | |
2100 | so that casts will be considered, but default promotions won't | |
2101 | be. | |
2102 | ||
2103 | LOCATION is the location of the comparison operator. | |
2104 | ||
2105 | The arguments of this function map directly to local variables | |
2106 | of build_binary_op. */ | |
2107 | ||
2108 | void | |
2109 | warn_for_sign_compare (location_t location, | |
2110 | tree orig_op0, tree orig_op1, | |
2111 | tree op0, tree op1, | |
2112 | tree result_type, enum tree_code resultcode) | |
2113 | { | |
76b7321d | 2114 | if (error_operand_p (orig_op0) || error_operand_p (orig_op1)) |
2115 | return; | |
2116 | ||
0f4cea33 | 2117 | int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0)); |
2118 | int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1)); | |
2119 | int unsignedp0, unsignedp1; | |
2120 | ||
2121 | /* In C++, check for comparison of different enum types. */ | |
2122 | if (c_dialect_cxx() | |
2123 | && TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE | |
2124 | && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE | |
2125 | && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0)) | |
2126 | != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1))) | |
2127 | { | |
2128 | warning_at (location, | |
2129 | OPT_Wsign_compare, "comparison between types %qT and %qT", | |
2130 | TREE_TYPE (orig_op0), TREE_TYPE (orig_op1)); | |
2131 | } | |
2132 | ||
2133 | /* Do not warn if the comparison is being done in a signed type, | |
2134 | since the signed type will only be chosen if it can represent | |
2135 | all the values of the unsigned type. */ | |
2136 | if (!TYPE_UNSIGNED (result_type)) | |
2137 | /* OK */; | |
2138 | /* Do not warn if both operands are unsigned. */ | |
2139 | else if (op0_signed == op1_signed) | |
2140 | /* OK */; | |
2141 | else | |
2142 | { | |
2143 | tree sop, uop, base_type; | |
2144 | bool ovf; | |
2145 | ||
2146 | if (op0_signed) | |
2147 | sop = orig_op0, uop = orig_op1; | |
2148 | else | |
2149 | sop = orig_op1, uop = orig_op0; | |
2150 | ||
b3902d2e | 2151 | sop = fold_for_warn (sop); |
2152 | uop = fold_for_warn (uop); | |
2153 | ||
0f4cea33 | 2154 | STRIP_TYPE_NOPS (sop); |
2155 | STRIP_TYPE_NOPS (uop); | |
2156 | base_type = (TREE_CODE (result_type) == COMPLEX_TYPE | |
2157 | ? TREE_TYPE (result_type) : result_type); | |
2158 | ||
2159 | /* Do not warn if the signed quantity is an unsuffixed integer | |
2160 | literal (or some static constant expression involving such | |
2161 | literals or a conditional expression involving such literals) | |
2162 | and it is non-negative. */ | |
2163 | if (tree_expr_nonnegative_warnv_p (sop, &ovf)) | |
2164 | /* OK */; | |
2165 | /* Do not warn if the comparison is an equality operation, the | |
2166 | unsigned quantity is an integral constant, and it would fit | |
2167 | in the result if the result were signed. */ | |
2168 | else if (TREE_CODE (uop) == INTEGER_CST | |
2169 | && (resultcode == EQ_EXPR || resultcode == NE_EXPR) | |
2170 | && int_fits_type_p (uop, c_common_signed_type (base_type))) | |
2171 | /* OK */; | |
2172 | /* In C, do not warn if the unsigned quantity is an enumeration | |
2173 | constant and its maximum value would fit in the result if the | |
2174 | result were signed. */ | |
2175 | else if (!c_dialect_cxx() && TREE_CODE (uop) == INTEGER_CST | |
2176 | && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE | |
2177 | && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)), | |
2178 | c_common_signed_type (base_type))) | |
2179 | /* OK */; | |
2180 | else | |
7d4d7ecb | 2181 | warning_at (location, OPT_Wsign_compare, |
2182 | "comparison of integer expressions of different " | |
2183 | "signedness: %qT and %qT", TREE_TYPE (orig_op0), | |
2184 | TREE_TYPE (orig_op1)); | |
0f4cea33 | 2185 | } |
2186 | ||
2187 | /* Warn if two unsigned values are being compared in a size larger | |
2188 | than their original size, and one (and only one) is the result of | |
2189 | a `~' operator. This comparison will always fail. | |
2190 | ||
2191 | Also warn if one operand is a constant, and the constant does not | |
2192 | have all bits set that are set in the ~ operand when it is | |
2193 | extended. */ | |
2194 | ||
2195 | op0 = c_common_get_narrower (op0, &unsignedp0); | |
2196 | op1 = c_common_get_narrower (op1, &unsignedp1); | |
2197 | ||
2198 | if ((TREE_CODE (op0) == BIT_NOT_EXPR) | |
2199 | ^ (TREE_CODE (op1) == BIT_NOT_EXPR)) | |
2200 | { | |
2201 | if (TREE_CODE (op0) == BIT_NOT_EXPR) | |
2202 | op0 = c_common_get_narrower (TREE_OPERAND (op0, 0), &unsignedp0); | |
2203 | if (TREE_CODE (op1) == BIT_NOT_EXPR) | |
2204 | op1 = c_common_get_narrower (TREE_OPERAND (op1, 0), &unsignedp1); | |
2205 | ||
2206 | if (tree_fits_shwi_p (op0) || tree_fits_shwi_p (op1)) | |
2207 | { | |
2208 | tree primop; | |
2209 | HOST_WIDE_INT constant, mask; | |
2210 | int unsignedp; | |
2211 | unsigned int bits; | |
2212 | ||
2213 | if (tree_fits_shwi_p (op0)) | |
2214 | { | |
2215 | primop = op1; | |
2216 | unsignedp = unsignedp1; | |
2217 | constant = tree_to_shwi (op0); | |
2218 | } | |
2219 | else | |
2220 | { | |
2221 | primop = op0; | |
2222 | unsignedp = unsignedp0; | |
2223 | constant = tree_to_shwi (op1); | |
2224 | } | |
2225 | ||
2226 | bits = TYPE_PRECISION (TREE_TYPE (primop)); | |
2227 | if (bits < TYPE_PRECISION (result_type) | |
2228 | && bits < HOST_BITS_PER_LONG && unsignedp) | |
2229 | { | |
2230 | mask = HOST_WIDE_INT_M1U << bits; | |
2231 | if ((mask & constant) != mask) | |
2232 | { | |
2233 | if (constant == 0) | |
2234 | warning_at (location, OPT_Wsign_compare, | |
2235 | "promoted ~unsigned is always non-zero"); | |
2236 | else | |
2237 | warning_at (location, OPT_Wsign_compare, | |
2238 | "comparison of promoted ~unsigned with constant"); | |
2239 | } | |
2240 | } | |
2241 | } | |
2242 | else if (unsignedp0 && unsignedp1 | |
2243 | && (TYPE_PRECISION (TREE_TYPE (op0)) | |
2244 | < TYPE_PRECISION (result_type)) | |
2245 | && (TYPE_PRECISION (TREE_TYPE (op1)) | |
2246 | < TYPE_PRECISION (result_type))) | |
2247 | warning_at (location, OPT_Wsign_compare, | |
2248 | "comparison of promoted ~unsigned with unsigned"); | |
2249 | } | |
2250 | } | |
2251 | ||
2252 | /* RESULT_TYPE is the result of converting TYPE1 and TYPE2 to a common | |
2253 | type via c_common_type. If -Wdouble-promotion is in use, and the | |
2254 | conditions for warning have been met, issue a warning. GMSGID is | |
2255 | the warning message. It must have two %T specifiers for the type | |
2256 | that was converted (generally "float") and the type to which it was | |
2257 | converted (generally "double), respectively. LOC is the location | |
2fbe7a32 | 2258 | to which the warning should refer. */ |
0f4cea33 | 2259 | |
2260 | void | |
2261 | do_warn_double_promotion (tree result_type, tree type1, tree type2, | |
2262 | const char *gmsgid, location_t loc) | |
2263 | { | |
2264 | tree source_type; | |
2265 | ||
2266 | if (!warn_double_promotion) | |
2267 | return; | |
2268 | /* If the conversion will not occur at run-time, there is no need to | |
2269 | warn about it. */ | |
2270 | if (c_inhibit_evaluation_warnings) | |
2271 | return; | |
0396f790 | 2272 | /* If an invalid conversion has occured, don't warn. */ |
2273 | if (result_type == error_mark_node) | |
2274 | return; | |
0f4cea33 | 2275 | if (TYPE_MAIN_VARIANT (result_type) != double_type_node |
2276 | && TYPE_MAIN_VARIANT (result_type) != complex_double_type_node) | |
2277 | return; | |
2278 | if (TYPE_MAIN_VARIANT (type1) == float_type_node | |
2279 | || TYPE_MAIN_VARIANT (type1) == complex_float_type_node) | |
2280 | source_type = type1; | |
2281 | else if (TYPE_MAIN_VARIANT (type2) == float_type_node | |
2282 | || TYPE_MAIN_VARIANT (type2) == complex_float_type_node) | |
2283 | source_type = type2; | |
2284 | else | |
2285 | return; | |
2286 | warning_at (loc, OPT_Wdouble_promotion, gmsgid, source_type, result_type); | |
2287 | } | |
2288 | ||
2289 | /* Possibly warn about unused parameters. */ | |
2290 | ||
2291 | void | |
2292 | do_warn_unused_parameter (tree fn) | |
2293 | { | |
2294 | tree decl; | |
2295 | ||
2296 | for (decl = DECL_ARGUMENTS (fn); | |
2297 | decl; decl = DECL_CHAIN (decl)) | |
2298 | if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL | |
2299 | && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl) | |
2300 | && !TREE_NO_WARNING (decl)) | |
2301 | warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wunused_parameter, | |
2302 | "unused parameter %qD", decl); | |
2303 | } | |
2304 | ||
2305 | /* If DECL is a typedef that is declared in the current function, | |
2306 | record it for the purpose of -Wunused-local-typedefs. */ | |
2307 | ||
2308 | void | |
2309 | record_locally_defined_typedef (tree decl) | |
2310 | { | |
2311 | struct c_language_function *l; | |
2312 | ||
2313 | if (!warn_unused_local_typedefs | |
2314 | || cfun == NULL | |
2315 | /* if this is not a locally defined typedef then we are not | |
2316 | interested. */ | |
2317 | || !is_typedef_decl (decl) | |
2318 | || !decl_function_context (decl)) | |
2319 | return; | |
2320 | ||
2321 | l = (struct c_language_function *) cfun->language; | |
2322 | vec_safe_push (l->local_typedefs, decl); | |
2323 | } | |
2324 | ||
2325 | /* If T is a TYPE_DECL declared locally, mark it as used. */ | |
2326 | ||
2327 | void | |
2328 | maybe_record_typedef_use (tree t) | |
2329 | { | |
2330 | if (!is_typedef_decl (t)) | |
2331 | return; | |
2332 | ||
2333 | TREE_USED (t) = true; | |
2334 | } | |
2335 | ||
2336 | /* Warn if there are some unused locally defined typedefs in the | |
2337 | current function. */ | |
2338 | ||
2339 | void | |
2340 | maybe_warn_unused_local_typedefs (void) | |
2341 | { | |
2342 | int i; | |
2343 | tree decl; | |
2344 | /* The number of times we have emitted -Wunused-local-typedefs | |
2345 | warnings. If this is different from errorcount, that means some | |
2346 | unrelated errors have been issued. In which case, we'll avoid | |
2347 | emitting "unused-local-typedefs" warnings. */ | |
2348 | static int unused_local_typedefs_warn_count; | |
2349 | struct c_language_function *l; | |
2350 | ||
2351 | if (cfun == NULL) | |
2352 | return; | |
2353 | ||
2354 | if ((l = (struct c_language_function *) cfun->language) == NULL) | |
2355 | return; | |
2356 | ||
2357 | if (warn_unused_local_typedefs | |
2358 | && errorcount == unused_local_typedefs_warn_count) | |
2359 | { | |
2360 | FOR_EACH_VEC_SAFE_ELT (l->local_typedefs, i, decl) | |
2361 | if (!TREE_USED (decl)) | |
2362 | warning_at (DECL_SOURCE_LOCATION (decl), | |
2363 | OPT_Wunused_local_typedefs, | |
2364 | "typedef %qD locally defined but not used", decl); | |
2365 | unused_local_typedefs_warn_count = errorcount; | |
2366 | } | |
2367 | ||
2368 | vec_free (l->local_typedefs); | |
2369 | } | |
2370 | ||
2371 | /* If we're creating an if-else-if condition chain, first see if we | |
2372 | already have this COND in the CHAIN. If so, warn and don't add COND | |
2373 | into the vector, otherwise add the COND there. LOC is the location | |
2374 | of COND. */ | |
2375 | ||
2376 | void | |
2377 | warn_duplicated_cond_add_or_warn (location_t loc, tree cond, vec<tree> **chain) | |
2378 | { | |
2379 | /* No chain has been created yet. Do nothing. */ | |
2380 | if (*chain == NULL) | |
2381 | return; | |
2382 | ||
2383 | if (TREE_SIDE_EFFECTS (cond)) | |
2384 | { | |
2385 | /* Uh-oh! This condition has a side-effect, thus invalidates | |
2386 | the whole chain. */ | |
2387 | delete *chain; | |
2388 | *chain = NULL; | |
2389 | return; | |
2390 | } | |
2391 | ||
2392 | unsigned int ix; | |
2393 | tree t; | |
2394 | bool found = false; | |
2395 | FOR_EACH_VEC_ELT (**chain, ix, t) | |
2396 | if (operand_equal_p (cond, t, 0)) | |
2397 | { | |
bc35ef65 | 2398 | auto_diagnostic_group d; |
0f4cea33 | 2399 | if (warning_at (loc, OPT_Wduplicated_cond, |
2400 | "duplicated %<if%> condition")) | |
2401 | inform (EXPR_LOCATION (t), "previously used here"); | |
2402 | found = true; | |
2403 | break; | |
2404 | } | |
2405 | ||
2406 | if (!found | |
2407 | && !CONSTANT_CLASS_P (cond) | |
2408 | /* Don't infinitely grow the chain. */ | |
2409 | && (*chain)->length () < 512) | |
2410 | (*chain)->safe_push (cond); | |
2411 | } | |
2412 | ||
2413 | /* Check and possibly warn if two declarations have contradictory | |
2414 | attributes, such as always_inline vs. noinline. */ | |
2415 | ||
2416 | bool | |
2417 | diagnose_mismatched_attributes (tree olddecl, tree newdecl) | |
2418 | { | |
2419 | bool warned = false; | |
2420 | ||
2421 | tree a1 = lookup_attribute ("optimize", DECL_ATTRIBUTES (olddecl)); | |
2422 | tree a2 = lookup_attribute ("optimize", DECL_ATTRIBUTES (newdecl)); | |
2423 | /* An optimization attribute applied on a declaration after the | |
2424 | definition is likely not what the user wanted. */ | |
2425 | if (a2 != NULL_TREE | |
2426 | && DECL_SAVED_TREE (olddecl) != NULL_TREE | |
2427 | && (a1 == NULL_TREE || !attribute_list_equal (a1, a2))) | |
2428 | warned |= warning (OPT_Wattributes, | |
2429 | "optimization attribute on %qD follows " | |
2430 | "definition but the attribute doesn%'t match", | |
2431 | newdecl); | |
2432 | ||
2433 | /* Diagnose inline __attribute__ ((noinline)) which is silly. */ | |
2434 | if (DECL_DECLARED_INLINE_P (newdecl) | |
2435 | && DECL_UNINLINABLE (olddecl) | |
fbdd91b9 | 2436 | && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl))) |
0f4cea33 | 2437 | warned |= warning (OPT_Wattributes, "inline declaration of %qD follows " |
fbdd91b9 | 2438 | "declaration with attribute %<noinline%>", newdecl); |
0f4cea33 | 2439 | else if (DECL_DECLARED_INLINE_P (olddecl) |
2440 | && DECL_UNINLINABLE (newdecl) | |
2441 | && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl))) | |
2442 | warned |= warning (OPT_Wattributes, "declaration of %q+D with attribute " | |
fbdd91b9 | 2443 | "%<noinline%> follows inline declaration", newdecl); |
dab0e385 | 2444 | |
0f4cea33 | 2445 | return warned; |
2446 | } | |
2447 | ||
2448 | /* Warn if signed left shift overflows. We don't warn | |
2449 | about left-shifting 1 into the sign bit in C++14; cf. | |
2450 | <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3367.html#1457> | |
1170ee75 | 2451 | and don't warn for C++2a at all, as signed left shifts never |
2452 | overflow. | |
0f4cea33 | 2453 | LOC is a location of the shift; OP0 and OP1 are the operands. |
2454 | Return true if an overflow is detected, false otherwise. */ | |
2455 | ||
2456 | bool | |
2457 | maybe_warn_shift_overflow (location_t loc, tree op0, tree op1) | |
2458 | { | |
2459 | if (TREE_CODE (op0) != INTEGER_CST | |
2460 | || TREE_CODE (op1) != INTEGER_CST) | |
2461 | return false; | |
2462 | ||
2463 | tree type0 = TREE_TYPE (op0); | |
2464 | unsigned int prec0 = TYPE_PRECISION (type0); | |
2465 | ||
2466 | /* Left-hand operand must be signed. */ | |
1170ee75 | 2467 | if (TYPE_UNSIGNED (type0) || cxx_dialect >= cxx2a) |
0f4cea33 | 2468 | return false; |
2469 | ||
e3d0f65c | 2470 | unsigned int min_prec = (wi::min_precision (wi::to_wide (op0), SIGNED) |
0f4cea33 | 2471 | + TREE_INT_CST_LOW (op1)); |
2472 | /* Handle the case of left-shifting 1 into the sign bit. | |
2473 | * However, shifting 1 _out_ of the sign bit, as in | |
2474 | * INT_MIN << 1, is considered an overflow. | |
2475 | */ | |
1170ee75 | 2476 | if (!tree_int_cst_sign_bit (op0) && min_prec == prec0 + 1) |
0f4cea33 | 2477 | { |
2478 | /* Never warn for C++14 onwards. */ | |
2479 | if (cxx_dialect >= cxx14) | |
2480 | return false; | |
2481 | /* Otherwise only if -Wshift-overflow=2. But return | |
2482 | true to signal an overflow for the sake of integer | |
2483 | constant expressions. */ | |
2484 | if (warn_shift_overflow < 2) | |
2485 | return true; | |
2486 | } | |
2487 | ||
2488 | bool overflowed = min_prec > prec0; | |
2489 | if (overflowed && c_inhibit_evaluation_warnings == 0) | |
2490 | warning_at (loc, OPT_Wshift_overflow_, | |
2491 | "result of %qE requires %u bits to represent, " | |
2492 | "but %qT only has %u bits", | |
2493 | build2_loc (loc, LSHIFT_EXPR, type0, op0, op1), | |
2494 | min_prec, type0, prec0); | |
2495 | ||
2496 | return overflowed; | |
2497 | } | |
2498 | ||
2499 | /* Warn about boolean expression compared with an integer value different | |
2500 | from true/false. Warns also e.g. about "(i1 == i2) == 2". | |
2501 | LOC is the location of the comparison, CODE is its code, OP0 and OP1 | |
2502 | are the operands of the comparison. The caller must ensure that | |
2503 | either operand is a boolean expression. */ | |
2504 | ||
2505 | void | |
2506 | maybe_warn_bool_compare (location_t loc, enum tree_code code, tree op0, | |
2507 | tree op1) | |
2508 | { | |
2509 | if (TREE_CODE_CLASS (code) != tcc_comparison) | |
2510 | return; | |
2511 | ||
2512 | tree f, cst; | |
2513 | if (f = fold_for_warn (op0), | |
2514 | TREE_CODE (f) == INTEGER_CST) | |
2515 | cst = op0 = f; | |
2516 | else if (f = fold_for_warn (op1), | |
2517 | TREE_CODE (f) == INTEGER_CST) | |
2518 | cst = op1 = f; | |
2519 | else | |
2520 | return; | |
2521 | ||
2522 | if (!integer_zerop (cst) && !integer_onep (cst)) | |
2523 | { | |
2524 | int sign = (TREE_CODE (op0) == INTEGER_CST | |
2525 | ? tree_int_cst_sgn (cst) : -tree_int_cst_sgn (cst)); | |
2526 | if (code == EQ_EXPR | |
2527 | || ((code == GT_EXPR || code == GE_EXPR) && sign < 0) | |
2528 | || ((code == LT_EXPR || code == LE_EXPR) && sign > 0)) | |
2529 | warning_at (loc, OPT_Wbool_compare, "comparison of constant %qE " | |
2530 | "with boolean expression is always false", cst); | |
2531 | else | |
2532 | warning_at (loc, OPT_Wbool_compare, "comparison of constant %qE " | |
2533 | "with boolean expression is always true", cst); | |
2534 | } | |
2535 | else if (integer_zerop (cst) || integer_onep (cst)) | |
2536 | { | |
2537 | /* If the non-constant operand isn't of a boolean type, we | |
2538 | don't want to warn here. */ | |
2539 | tree noncst = TREE_CODE (op0) == INTEGER_CST ? op1 : op0; | |
2540 | /* Handle booleans promoted to integers. */ | |
2541 | if (bool_promoted_to_int_p (noncst)) | |
2542 | /* Warn. */; | |
2543 | else if (TREE_CODE (TREE_TYPE (noncst)) != BOOLEAN_TYPE | |
2544 | && !truth_value_p (TREE_CODE (noncst))) | |
2545 | return; | |
2546 | /* Do some magic to get the right diagnostics. */ | |
2547 | bool flag = TREE_CODE (op0) == INTEGER_CST; | |
2548 | flag = integer_zerop (cst) ? flag : !flag; | |
2549 | if ((code == GE_EXPR && !flag) || (code == LE_EXPR && flag)) | |
2550 | warning_at (loc, OPT_Wbool_compare, "comparison of constant %qE " | |
2551 | "with boolean expression is always true", cst); | |
2552 | else if ((code == LT_EXPR && !flag) || (code == GT_EXPR && flag)) | |
2553 | warning_at (loc, OPT_Wbool_compare, "comparison of constant %qE " | |
2554 | "with boolean expression is always false", cst); | |
2555 | } | |
2556 | } | |
9bf6a8e0 | 2557 | |
2558 | /* Warn if an argument at position param_pos is passed to a | |
75e9093e | 2559 | restrict-qualified param, and it aliases with another argument. |
2560 | Return true if a warning has been issued. */ | |
9bf6a8e0 | 2561 | |
75e9093e | 2562 | bool |
bbd5521e | 2563 | warn_for_restrict (unsigned param_pos, tree *argarray, unsigned nargs) |
9bf6a8e0 | 2564 | { |
bbd5521e | 2565 | tree arg = argarray[param_pos]; |
2566 | if (TREE_VISITED (arg) || integer_zerop (arg)) | |
75e9093e | 2567 | return false; |
9bf6a8e0 | 2568 | |
2569 | location_t loc = EXPR_LOC_OR_LOC (arg, input_location); | |
2570 | gcc_rich_location richloc (loc); | |
2571 | ||
2572 | unsigned i; | |
bbd5521e | 2573 | auto_vec<int, 16> arg_positions; |
9bf6a8e0 | 2574 | |
bbd5521e | 2575 | for (i = 0; i < nargs; i++) |
9bf6a8e0 | 2576 | { |
2577 | if (i == param_pos) | |
2578 | continue; | |
2579 | ||
bbd5521e | 2580 | tree current_arg = argarray[i]; |
9bf6a8e0 | 2581 | if (operand_equal_p (arg, current_arg, 0)) |
2582 | { | |
75e9093e | 2583 | TREE_VISITED (current_arg) = 1; |
bbd5521e | 2584 | arg_positions.safe_push (i + 1); |
9bf6a8e0 | 2585 | } |
2586 | } | |
2587 | ||
bbd5521e | 2588 | if (arg_positions.is_empty ()) |
75e9093e | 2589 | return false; |
9bf6a8e0 | 2590 | |
bbd5521e | 2591 | int pos; |
2592 | FOR_EACH_VEC_ELT (arg_positions, i, pos) | |
9bf6a8e0 | 2593 | { |
bbd5521e | 2594 | arg = argarray[pos - 1]; |
9bf6a8e0 | 2595 | if (EXPR_HAS_LOCATION (arg)) |
5fe20025 | 2596 | richloc.add_range (EXPR_LOCATION (arg)); |
9bf6a8e0 | 2597 | } |
2598 | ||
75e9093e | 2599 | return warning_n (&richloc, OPT_Wrestrict, arg_positions.length (), |
2600 | "passing argument %i to restrict-qualified parameter" | |
2601 | " aliases with argument %Z", | |
2602 | "passing argument %i to restrict-qualified parameter" | |
2603 | " aliases with arguments %Z", | |
2604 | param_pos + 1, arg_positions.address (), | |
2605 | arg_positions.length ()); | |
9bf6a8e0 | 2606 | } |
3ef7eab1 | 2607 | |
2608 | /* Callback function to determine whether an expression TP or one of its | |
2609 | subexpressions comes from macro expansion. Used to suppress bogus | |
2610 | warnings. */ | |
2611 | ||
2612 | static tree | |
2613 | expr_from_macro_expansion_r (tree *tp, int *, void *) | |
2614 | { | |
2615 | if (CAN_HAVE_LOCATION_P (*tp) | |
2616 | && from_macro_expansion_at (EXPR_LOCATION (*tp))) | |
2617 | return integer_zero_node; | |
2618 | ||
2619 | return NULL_TREE; | |
2620 | } | |
2621 | ||
2622 | /* Possibly warn when an if-else has identical branches. */ | |
2623 | ||
2624 | static void | |
2625 | do_warn_duplicated_branches (tree expr) | |
2626 | { | |
2627 | tree thenb = COND_EXPR_THEN (expr); | |
2628 | tree elseb = COND_EXPR_ELSE (expr); | |
2629 | ||
314b4196 | 2630 | /* Don't bother if any of the branches is missing. */ |
2631 | if (thenb == NULL_TREE || elseb == NULL_TREE) | |
3ef7eab1 | 2632 | return; |
2633 | ||
2634 | /* And don't warn for empty statements. */ | |
2635 | if (TREE_CODE (thenb) == NOP_EXPR | |
2636 | && TREE_TYPE (thenb) == void_type_node | |
2637 | && TREE_OPERAND (thenb, 0) == size_zero_node) | |
2638 | return; | |
2639 | ||
2640 | /* ... or empty branches. */ | |
2641 | if (TREE_CODE (thenb) == STATEMENT_LIST | |
2642 | && STATEMENT_LIST_HEAD (thenb) == NULL) | |
2643 | return; | |
2644 | ||
2645 | /* Compute the hash of the then branch. */ | |
2646 | inchash::hash hstate0 (0); | |
2647 | inchash::add_expr (thenb, hstate0); | |
2648 | hashval_t h0 = hstate0.end (); | |
2649 | ||
2650 | /* Compute the hash of the else branch. */ | |
2651 | inchash::hash hstate1 (0); | |
2652 | inchash::add_expr (elseb, hstate1); | |
2653 | hashval_t h1 = hstate1.end (); | |
2654 | ||
2655 | /* Compare the hashes. */ | |
2656 | if (h0 == h1 | |
2657 | && operand_equal_p (thenb, elseb, OEP_LEXICOGRAPHIC) | |
2658 | /* Don't warn if any of the branches or their subexpressions comes | |
2659 | from a macro. */ | |
2660 | && !walk_tree_without_duplicates (&thenb, expr_from_macro_expansion_r, | |
2661 | NULL) | |
2662 | && !walk_tree_without_duplicates (&elseb, expr_from_macro_expansion_r, | |
2663 | NULL)) | |
2664 | warning_at (EXPR_LOCATION (expr), OPT_Wduplicated_branches, | |
2665 | "this condition has identical branches"); | |
2666 | } | |
2667 | ||
2668 | /* Callback for c_genericize to implement -Wduplicated-branches. */ | |
2669 | ||
2670 | tree | |
2671 | do_warn_duplicated_branches_r (tree *tp, int *, void *) | |
2672 | { | |
2673 | if (TREE_CODE (*tp) == COND_EXPR) | |
2674 | do_warn_duplicated_branches (*tp); | |
2675 | return NULL_TREE; | |
2676 | } | |
2bfb0686 | 2677 | |
2678 | /* Implementation of -Wmultistatement-macros. This warning warns about | |
2679 | cases when a macro expands to multiple statements not wrapped in | |
2680 | do {} while (0) or ({ }) and is used as a body of if/else/for/while | |
2681 | conditionals. For example, | |
2682 | ||
2683 | #define DOIT x++; y++ | |
2684 | ||
2685 | if (c) | |
2686 | DOIT; | |
2687 | ||
2688 | will increment y unconditionally. | |
2689 | ||
2690 | BODY_LOC is the location of the first token in the body after labels | |
2691 | have been parsed, NEXT_LOC is the location of the next token after the | |
2692 | body of the conditional has been parsed, and GUARD_LOC is the location | |
2693 | of the conditional. */ | |
2694 | ||
2695 | void | |
2696 | warn_for_multistatement_macros (location_t body_loc, location_t next_loc, | |
2697 | location_t guard_loc, enum rid keyword) | |
2698 | { | |
2699 | if (!warn_multistatement_macros) | |
2700 | return; | |
2701 | ||
2702 | /* Ain't got time to waste. We only care about macros here. */ | |
2703 | if (!from_macro_expansion_at (body_loc) | |
2704 | || !from_macro_expansion_at (next_loc)) | |
2705 | return; | |
2706 | ||
2707 | /* Let's skip macros defined in system headers. */ | |
2708 | if (in_system_header_at (body_loc) | |
2709 | || in_system_header_at (next_loc)) | |
2710 | return; | |
2711 | ||
2712 | /* Find the actual tokens in the macro definition. BODY_LOC and | |
2713 | NEXT_LOC have to come from the same spelling location, but they | |
2714 | will resolve to different locations in the context of the macro | |
2715 | definition. */ | |
2716 | location_t body_loc_exp | |
2717 | = linemap_resolve_location (line_table, body_loc, | |
2718 | LRK_MACRO_DEFINITION_LOCATION, NULL); | |
2719 | location_t next_loc_exp | |
2720 | = linemap_resolve_location (line_table, next_loc, | |
2721 | LRK_MACRO_DEFINITION_LOCATION, NULL); | |
2722 | location_t guard_loc_exp | |
2723 | = linemap_resolve_location (line_table, guard_loc, | |
2724 | LRK_MACRO_DEFINITION_LOCATION, NULL); | |
2725 | ||
2726 | /* These are some funky cases we don't want to warn about. */ | |
2727 | if (body_loc_exp == guard_loc_exp | |
2728 | || next_loc_exp == guard_loc_exp | |
2729 | || body_loc_exp == next_loc_exp) | |
2730 | return; | |
2731 | ||
ef85bba9 | 2732 | /* Find the macro maps for the macro expansions. */ |
2733 | const line_map *body_map = linemap_lookup (line_table, body_loc); | |
2734 | const line_map *next_map = linemap_lookup (line_table, next_loc); | |
2735 | const line_map *guard_map = linemap_lookup (line_table, guard_loc); | |
2736 | ||
2737 | /* Now see if the following token (after the body) is coming from the | |
2738 | same macro expansion. If it is, it might be a problem. */ | |
2739 | if (body_map != next_map) | |
2740 | return; | |
2bfb0686 | 2741 | |
2742 | /* The conditional itself must not come from the same expansion, because | |
2743 | we don't want to warn about | |
2744 | #define IF if (x) x++; y++ | |
2745 | and similar. */ | |
ef85bba9 | 2746 | if (guard_map == body_map) |
2bfb0686 | 2747 | return; |
2748 | ||
ef85bba9 | 2749 | /* Handle the case where NEXT and BODY come from the same expansion while |
2750 | GUARD doesn't, yet we shouldn't warn. E.g. | |
2751 | ||
2752 | #define GUARD if (...) | |
2753 | #define GUARD2 GUARD | |
2754 | ||
2755 | and in the definition of another macro: | |
2756 | ||
2757 | GUARD2 | |
2758 | foo (); | |
2759 | return 1; | |
2760 | */ | |
2761 | while (linemap_macro_expansion_map_p (guard_map)) | |
2762 | { | |
2763 | const line_map_macro *mm = linemap_check_macro (guard_map); | |
2764 | guard_loc_exp = MACRO_MAP_EXPANSION_POINT_LOCATION (mm); | |
2765 | guard_map = linemap_lookup (line_table, guard_loc_exp); | |
2766 | if (guard_map == body_map) | |
2767 | return; | |
2768 | } | |
2769 | ||
bc35ef65 | 2770 | auto_diagnostic_group d; |
2bfb0686 | 2771 | if (warning_at (body_loc, OPT_Wmultistatement_macros, |
2772 | "macro expands to multiple statements")) | |
2773 | inform (guard_loc, "some parts of macro expansion are not guarded by " | |
2774 | "this %qs clause", guard_tinfo_to_string (keyword)); | |
2775 | } | |
5c934723 | 2776 | |
2777 | /* Return struct or union type if the alignment of data memeber, FIELD, | |
8144bd52 | 2778 | is less than the alignment of TYPE. Otherwise, return NULL_TREE. |
2779 | If RVALUE is true, only arrays evaluate to pointers. */ | |
5c934723 | 2780 | |
2781 | static tree | |
8144bd52 | 2782 | check_alignment_of_packed_member (tree type, tree field, bool rvalue) |
5c934723 | 2783 | { |
2784 | /* Check alignment of the data member. */ | |
2785 | if (TREE_CODE (field) == FIELD_DECL | |
8144bd52 | 2786 | && (DECL_PACKED (field) || TYPE_PACKED (TREE_TYPE (field))) |
2787 | && (!rvalue || TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE)) | |
5c934723 | 2788 | { |
2789 | /* Check the expected alignment against the field alignment. */ | |
8144bd52 | 2790 | unsigned int type_align = min_align_of_type (type); |
5c934723 | 2791 | tree context = DECL_CONTEXT (field); |
8144bd52 | 2792 | unsigned int record_align = min_align_of_type (context); |
2793 | if (record_align < type_align) | |
5c934723 | 2794 | return context; |
2795 | tree field_off = byte_position (field); | |
2796 | if (!multiple_of_p (TREE_TYPE (field_off), field_off, | |
8144bd52 | 2797 | size_int (type_align))) |
5c934723 | 2798 | return context; |
2799 | } | |
2800 | ||
2801 | return NULL_TREE; | |
2802 | } | |
2803 | ||
6d4e8a95 | 2804 | /* Return struct or union type if the right hand value, RHS: |
2805 | 1. Is a pointer value which isn't aligned to a pointer type TYPE. | |
2806 | 2. Is an address which takes the unaligned address of packed member | |
2807 | of struct or union when assigning to TYPE. | |
2808 | Otherwise, return NULL_TREE. */ | |
5c934723 | 2809 | |
2810 | static tree | |
6d4e8a95 | 2811 | check_address_or_pointer_of_packed_member (tree type, tree rhs) |
5c934723 | 2812 | { |
8144bd52 | 2813 | bool rvalue = true; |
a6061e19 | 2814 | bool indirect = false; |
8144bd52 | 2815 | |
5c934723 | 2816 | if (INDIRECT_REF_P (rhs)) |
a6061e19 | 2817 | { |
2818 | rhs = TREE_OPERAND (rhs, 0); | |
2819 | STRIP_NOPS (rhs); | |
2820 | indirect = true; | |
2821 | } | |
5c934723 | 2822 | |
2823 | if (TREE_CODE (rhs) == ADDR_EXPR) | |
8144bd52 | 2824 | { |
2825 | rhs = TREE_OPERAND (rhs, 0); | |
a6061e19 | 2826 | rvalue = indirect; |
8144bd52 | 2827 | } |
2828 | ||
2829 | if (!POINTER_TYPE_P (type)) | |
2830 | return NULL_TREE; | |
5c934723 | 2831 | |
8144bd52 | 2832 | type = TREE_TYPE (type); |
6d4e8a95 | 2833 | |
2834 | if (TREE_CODE (rhs) == PARM_DECL | |
2835 | || VAR_P (rhs) | |
2836 | || TREE_CODE (rhs) == CALL_EXPR) | |
2837 | { | |
8144bd52 | 2838 | tree rhstype = TREE_TYPE (rhs); |
6d4e8a95 | 2839 | if (TREE_CODE (rhs) == CALL_EXPR) |
2840 | { | |
2841 | rhs = CALL_EXPR_FN (rhs); /* Pointer expression. */ | |
2842 | if (rhs == NULL_TREE) | |
2843 | return NULL_TREE; | |
2844 | rhs = TREE_TYPE (rhs); /* Pointer type. */ | |
2845 | rhs = TREE_TYPE (rhs); /* Function type. */ | |
8144bd52 | 2846 | rhstype = TREE_TYPE (rhs); |
1e689000 | 2847 | if (!rhstype || !POINTER_TYPE_P (rhstype)) |
8144bd52 | 2848 | return NULL_TREE; |
2849 | rvalue = true; | |
6d4e8a95 | 2850 | } |
8144bd52 | 2851 | if (rvalue && POINTER_TYPE_P (rhstype)) |
2852 | rhstype = TREE_TYPE (rhstype); | |
2853 | while (TREE_CODE (rhstype) == ARRAY_TYPE) | |
2854 | rhstype = TREE_TYPE (rhstype); | |
2855 | if (TYPE_PACKED (rhstype)) | |
6d4e8a95 | 2856 | { |
8144bd52 | 2857 | unsigned int type_align = min_align_of_type (type); |
2858 | unsigned int rhs_align = min_align_of_type (rhstype); | |
2859 | if (rhs_align < type_align) | |
6d4e8a95 | 2860 | { |
d0162866 | 2861 | auto_diagnostic_group d; |
6d4e8a95 | 2862 | location_t location = EXPR_LOC_OR_LOC (rhs, input_location); |
d0162866 | 2863 | if (warning_at (location, OPT_Waddress_of_packed_member, |
2864 | "converting a packed %qT pointer (alignment %d) " | |
2865 | "to a %qT pointer (alignment %d) may result in " | |
2866 | "an unaligned pointer value", | |
2867 | rhstype, rhs_align, type, type_align)) | |
2868 | { | |
2869 | tree decl = TYPE_STUB_DECL (rhstype); | |
2870 | if (decl) | |
2871 | inform (DECL_SOURCE_LOCATION (decl), "defined here"); | |
2872 | decl = TYPE_STUB_DECL (type); | |
2873 | if (decl) | |
2874 | inform (DECL_SOURCE_LOCATION (decl), "defined here"); | |
2875 | } | |
6d4e8a95 | 2876 | } |
2877 | } | |
2878 | return NULL_TREE; | |
2879 | } | |
2880 | ||
5c934723 | 2881 | tree context = NULL_TREE; |
2882 | ||
2883 | /* Check alignment of the object. */ | |
2884 | while (handled_component_p (rhs)) | |
2885 | { | |
2886 | if (TREE_CODE (rhs) == COMPONENT_REF) | |
2887 | { | |
2888 | tree field = TREE_OPERAND (rhs, 1); | |
8144bd52 | 2889 | context = check_alignment_of_packed_member (type, field, rvalue); |
5c934723 | 2890 | if (context) |
2891 | break; | |
2892 | } | |
a6061e19 | 2893 | if (TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE) |
2894 | rvalue = false; | |
2895 | if (rvalue) | |
2896 | return NULL_TREE; | |
5c934723 | 2897 | rhs = TREE_OPERAND (rhs, 0); |
2898 | } | |
2899 | ||
2900 | return context; | |
2901 | } | |
2902 | ||
6d4e8a95 | 2903 | /* Check and warn if the right hand value, RHS: |
2904 | 1. Is a pointer value which isn't aligned to a pointer type TYPE. | |
2905 | 2. Is an address which takes the unaligned address of packed member | |
2906 | of struct or union when assigning to TYPE. | |
2907 | */ | |
5c934723 | 2908 | |
2909 | static void | |
6d4e8a95 | 2910 | check_and_warn_address_or_pointer_of_packed_member (tree type, tree rhs) |
5c934723 | 2911 | { |
a6061e19 | 2912 | bool nop_p = false; |
2913 | tree orig_rhs; | |
6d4e8a95 | 2914 | |
a6061e19 | 2915 | do |
2916 | { | |
2917 | while (TREE_CODE (rhs) == COMPOUND_EXPR) | |
2918 | rhs = TREE_OPERAND (rhs, 1); | |
2919 | orig_rhs = rhs; | |
2920 | STRIP_NOPS (rhs); | |
2921 | nop_p |= orig_rhs != rhs; | |
2922 | } | |
2923 | while (orig_rhs != rhs); | |
6d4e8a95 | 2924 | |
2925 | if (TREE_CODE (rhs) == COND_EXPR) | |
5c934723 | 2926 | { |
6d4e8a95 | 2927 | /* Check the THEN path. */ |
2928 | check_and_warn_address_or_pointer_of_packed_member | |
2929 | (type, TREE_OPERAND (rhs, 1)); | |
5c934723 | 2930 | |
6d4e8a95 | 2931 | /* Check the ELSE path. */ |
2932 | check_and_warn_address_or_pointer_of_packed_member | |
2933 | (type, TREE_OPERAND (rhs, 2)); | |
2934 | } | |
2935 | else | |
2936 | { | |
2937 | if (nop_p) | |
2938 | { | |
2939 | switch (TREE_CODE (rhs)) | |
2940 | { | |
2941 | case ADDR_EXPR: | |
2942 | /* Address is taken. */ | |
2943 | case PARM_DECL: | |
2944 | case VAR_DECL: | |
2945 | /* Pointer conversion. */ | |
2946 | break; | |
2947 | case CALL_EXPR: | |
2948 | /* Function call. */ | |
2949 | break; | |
2950 | default: | |
2951 | return; | |
2952 | } | |
2953 | } | |
2954 | ||
2955 | tree context | |
2956 | = check_address_or_pointer_of_packed_member (type, rhs); | |
5c934723 | 2957 | if (context) |
2958 | { | |
2959 | location_t loc = EXPR_LOC_OR_LOC (rhs, input_location); | |
2960 | warning_at (loc, OPT_Waddress_of_packed_member, | |
2961 | "taking address of packed member of %qT may result " | |
2962 | "in an unaligned pointer value", | |
2963 | context); | |
2964 | } | |
5c934723 | 2965 | } |
5c934723 | 2966 | } |
2967 | ||
2968 | /* Warn if the right hand value, RHS: | |
6d4e8a95 | 2969 | 1. Is a pointer value which isn't aligned to a pointer type TYPE. |
2970 | 2. Is an address which takes the unaligned address of packed member | |
2971 | of struct or union when assigning to TYPE. | |
5c934723 | 2972 | */ |
2973 | ||
2974 | void | |
6d4e8a95 | 2975 | warn_for_address_or_pointer_of_packed_member (tree type, tree rhs) |
5c934723 | 2976 | { |
2977 | if (!warn_address_of_packed_member) | |
2978 | return; | |
2979 | ||
2980 | /* Don't warn if we don't assign RHS to a pointer. */ | |
2981 | if (!POINTER_TYPE_P (type)) | |
2982 | return; | |
2983 | ||
6d4e8a95 | 2984 | check_and_warn_address_or_pointer_of_packed_member (type, rhs); |
5c934723 | 2985 | } |