expr_fold.c revision 1.11 
1/*	$NetBSD: expr_fold.c,v 1.11 2024/01/06 15:05:24 rillig Exp $	*/
2# 3 "expr_fold.c"
3
4/*
5 * Test folding of constant expressions.
6 */
7
8/* lint1-extra-flags: -h -X 351 */
9
10/*
11 * On ILP32 platforms, the integer constant 2147483648 cannot be represented
12 * as 'int' or 'long', therefore it becomes 'long long'.  This would
13 * influence the type names in the diagnostics.
14 */
15/* lint1-only-if: lp64 */
16
17void take_bool(_Bool);
18void take_int(int);
19void take_uint(unsigned int);
20
21/*
22 * C99 6.4.4.1p5 defines that decimal integer constants without suffix get
23 * one of the signed integer types. On the other hand, octal and hexadecimal
24 * constants get either a signed or unsigned type, whichever fits first.
25 */
26
27void
28fold_uplus(void)
29{
30	take_int(+(0));
31	take_int(+(2147483647));
32	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
33	take_int(+(2147483648));
34	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
35	take_int(+(4294967295));
36
37	take_uint(+(0));
38	take_uint(+(2147483647));
39	take_uint(+(2147483648));
40	take_uint(+(4294967295));
41
42	/*
43	 * Hexadecimal constants and constants with the suffix 'U' get either
44	 * a signed or an unsigned integer type, so no warning here.
45	 */
46	take_uint(+(2147483648U));
47	take_uint(+(0x80000000));
48	take_uint(+(0x80000000U));
49}
50
51void
52fold_uminus(void)
53{
54	take_int(-(0));
55	take_int(-(2147483647));
56
57	take_int(-(2147483648));
58
59	/* The '-' is an operator, it is not part of the integer constant. */
60	take_int(-2147483648);
61
62	/* expect+2: warning: operator '+' produces integer overflow [141] */
63	/* expect+1: warning: operator '-' produces integer overflow [141] */
64	take_int(-(2147483647 + 1));
65	/* expect+1: warning: operator '-' produces integer overflow [141] */
66	take_int(-(-2147483647 - 1));
67	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
68	take_int(-(4294967295));
69
70	take_uint(-(0));
71	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
72	take_uint(-(2147483647));
73	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
74	take_uint(-(2147483648));
75	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
76	take_uint(-(4294967295));
77}
78
79void
80fold_compl(void)
81{
82	take_int(~(0));
83	take_int(~(2147483647));
84	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
85	take_int(~(2147483648));
86	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
87	take_int(~(4294967295));
88
89	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
90	take_uint(~(0));
91	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
92	take_uint(~(2147483647));
93	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
94	take_uint(~(2147483648));
95	/* expect+1: warning: conversion of negative constant to unsigned type, arg #1 [296] */
96	take_uint(~(4294967295));
97}
98
99void
100fold_mult(void)
101{
102	take_int(32767 * 65536);
103	/* expect+1: warning: operator '*' produces integer overflow [141] */
104	take_int(32768 * 65536);
105	/* expect+1: warning: operator '*' produces integer overflow [141] */
106	take_int(65536 * 65536);
107
108	take_uint(32767 * 65536U);
109	take_uint(32768 * 65536U);
110	/* expect+1: warning: operator '*' produces integer overflow [141] */
111	take_uint(65536 * 65536U);
112}
113
114void
115fold_div(void)
116{
117	/* expect+3: error: division by 0 [139] */
118	/* XXX: The following message is redundant. */
119	/* expect+1: warning: operator '/' produces integer overflow [141] */
120	take_int(0 / 0);
121
122	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
123	take_int(-2147483648 / -1);
124}
125
126void
127fold_mod(void)
128{
129	/* expect+1: error: modulus by 0 [140] */
130	take_int(0 % 0);
131	/* expect+1: error: modulus by 0 [140] */
132	take_int(0 % 0U);
133	/* expect+1: error: modulus by 0 [140] */
134	take_int(0U % 0);
135	/* expect+1: error: modulus by 0 [140] */
136	take_int(0U % 0U);
137
138	take_int(-2147483648 % -1);
139}
140
141void
142fold_plus(void)
143{
144	/* expect+1: warning: operator '+' produces integer overflow [141] */
145	take_int(2147483647 + 1);
146
147	/* Assume two's complement, so no overflow. */
148	take_int(-2147483647 + -1);
149
150	/* expect+1: warning: operator '+' produces integer overflow [141] */
151	take_int(-2147483647 + -2);
152
153	/*
154	 * No overflow since one of the operands is unsigned, therefore the
155	 * other operand is converted to unsigned as well.
156	 * See C99 6.3.1.8p1, paragraph 8 of 10.
157	 */
158	/* wrong integer overflow warning before tree.c 1.338 from 2021-08-19 */
159	take_uint(2147483647 + 1U);
160	/* wrong integer overflow warning before tree.c 1.338 from 2021-08-19 */
161	take_uint(2147483647U + 1);
162}
163
164void
165fold_minus(void)
166{
167	/* expect+1: warning: operator '-' produces integer overflow [141] */
168	take_int(2147483647 - -1);
169	/* Assume two's complement. */
170	take_int(-2147483647 - 1);
171	/* expect+1: warning: operator '-' produces integer overflow [141] */
172	take_int(-2147483647 - 2);
173
174	take_int(0 - 2147483648);
175	/* expect+1: warning: operator '-' produces integer overflow [141] */
176	take_uint(0 - 2147483648U);
177}
178
179void
180fold_shl(void)
181{
182	/* expect+1: warning: operator '<<' produces integer overflow [141] */
183	take_int(1 << 24 << 24);
184
185	/* expect+1: warning: operator '<<' produces integer overflow [141] */
186	take_uint(1U << 24 << 24);
187
188	/* expect+1: warning: shift amount 104 is greater than bit-size 32 of 'unsigned int' [122] */
189	take_uint(1U << 24 << 104);
190}
191
192void
193fold_shr(void)
194{
195	take_int(16777216 >> 24);
196
197	take_int(16777216 >> 25);
198
199	/* expect+1: warning: shift amount 104 is greater than bit-size 32 of 'int' [122] */
200	take_int(16777216 >> 104);
201}
202
203void
204fold_lt(void)
205{
206	take_bool(1 < 3);
207	take_bool(3 < 1);
208}
209
210void
211fold_le(void)
212{
213	take_bool(1 <= 3);
214	take_bool(3 <= 1);
215}
216
217void
218fold_ge(void)
219{
220	take_bool(1 >= 3);
221	take_bool(3 >= 1);
222}
223
224void
225fold_gt(void)
226{
227	take_bool(1 > 3);
228	take_bool(3 > 1);
229}
230
231void
232fold_eq(void)
233{
234	take_bool(1 == 3);
235	take_bool(3 == 1);
236}
237
238void
239fold_ne(void)
240{
241	take_bool(1 != 3);
242	take_bool(3 != 1);
243}
244
245void
246fold_bitand(void)
247{
248	take_bool(1 & 3);
249	take_bool(3 & 1);
250}
251
252void
253fold_bitxor(void)
254{
255	take_bool(1 ^ 3);
256	take_bool(3 ^ 1);
257}
258
259void
260fold_bitor(void)
261{
262	take_bool(1 | 3);
263	take_bool(3 | 1);
264}
265
266/*
267 * The following expression originated in vndcompress.c 1.29 from 2017-07-29,
268 * where line 310 contained a seemingly harmless compile-time assertion that
269 * expanded to a real monster expression.
270 *
271 * __CTASSERT(MUL_OK(uint64_t, MAX_N_BLOCKS, MAX_BLOCKSIZE));
272 *
273 * Before tree.c 1.345 from 2021-08-22, lint wrongly assumed that the result
274 * of all binary operators were the common arithmetic type, but that was
275 * wrong for the comparison operators.  The expression '1ULL < 2ULL' does not
276 * have type 'unsigned long long' but 'int' in default mode, or '_Bool' in
277 * strict bool mode.
278 */
279struct ctassert5_struct {
280	unsigned int member:
281	    /*CONSTCOND*/
282	    0xfffffffeU
283	    <=
284		((1ULL << 63) + 1 < 1 ? ~(1ULL << 63) : ~0ULL) / 0xfffffe00U
285		? 1
286		: -1;
287};
288
289/*
290 * Since Makefile.inc 1.21 from 2022-04-08 (which added -ftrapv) and before
291 * tree.c 1.436 from 2022-04-20, lint crashed with an integer overflow when
292 * calculating '-(uint64_t)INT64_MIN' in val_t.u.integer.
293 */
294void
295unary_minus_overflow(unsigned long long val)
296{
297	/* expect+1: warning: operator '-' produces integer overflow [141] */
298	if (val > -(unsigned long long)(-0x7fffffffffffffffL - 1))
299		return;
300}
301