expr_fold.c revision 1.12 
1/*	$NetBSD: expr_fold.c,v 1.12 2024/03/09 23:55:11 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+1: error: division by 0 [139] */
118	take_int(0 / 0);
119
120	/* expect+1: warning: conversion of 'long' to 'int' is out of range, arg #1 [295] */
121	take_int(-2147483648 / -1);
122}
123
124void
125fold_mod(void)
126{
127	/* expect+1: error: modulus by 0 [140] */
128	take_int(0 % 0);
129	/* expect+1: error: modulus by 0 [140] */
130	take_int(0 % 0U);
131	/* expect+1: error: modulus by 0 [140] */
132	take_int(0U % 0);
133	/* expect+1: error: modulus by 0 [140] */
134	take_int(0U % 0U);
135
136	take_int(-2147483648 % -1);
137}
138
139void
140fold_plus(void)
141{
142	/* expect+1: warning: operator '+' produces integer overflow [141] */
143	take_int(2147483647 + 1);
144
145	/* Assume two's complement, so no overflow. */
146	take_int(-2147483647 + -1);
147
148	/* expect+1: warning: operator '+' produces integer overflow [141] */
149	take_int(-2147483647 + -2);
150
151	/*
152	 * No overflow since one of the operands is unsigned, therefore the
153	 * other operand is converted to unsigned as well.
154	 * See C99 6.3.1.8p1, paragraph 8 of 10.
155	 */
156	/* wrong integer overflow warning before tree.c 1.338 from 2021-08-19 */
157	take_uint(2147483647 + 1U);
158	/* wrong integer overflow warning before tree.c 1.338 from 2021-08-19 */
159	take_uint(2147483647U + 1);
160}
161
162void
163fold_minus(void)
164{
165	/* expect+1: warning: operator '-' produces integer overflow [141] */
166	take_int(2147483647 - -1);
167	/* Assume two's complement. */
168	take_int(-2147483647 - 1);
169	/* expect+1: warning: operator '-' produces integer overflow [141] */
170	take_int(-2147483647 - 2);
171
172	take_int(0 - 2147483648);
173	/* expect+1: warning: operator '-' produces integer overflow [141] */
174	take_uint(0 - 2147483648U);
175}
176
177void
178fold_shl(void)
179{
180	/* expect+1: warning: operator '<<' produces integer overflow [141] */
181	take_int(1 << 24 << 24);
182
183	/* expect+1: warning: operator '<<' produces integer overflow [141] */
184	take_uint(1U << 24 << 24);
185
186	/* expect+1: warning: shift amount 104 is greater than bit-size 32 of 'unsigned int' [122] */
187	take_uint(1U << 24 << 104);
188}
189
190void
191fold_shr(void)
192{
193	take_int(16777216 >> 24);
194
195	take_int(16777216 >> 25);
196
197	/* expect+1: warning: shift amount 104 is greater than bit-size 32 of 'int' [122] */
198	take_int(16777216 >> 104);
199}
200
201void
202fold_lt(void)
203{
204	take_bool(1 < 3);
205	take_bool(3 < 1);
206}
207
208void
209fold_le(void)
210{
211	take_bool(1 <= 3);
212	take_bool(3 <= 1);
213}
214
215void
216fold_ge(void)
217{
218	take_bool(1 >= 3);
219	take_bool(3 >= 1);
220}
221
222void
223fold_gt(void)
224{
225	take_bool(1 > 3);
226	take_bool(3 > 1);
227}
228
229void
230fold_eq(void)
231{
232	take_bool(1 == 3);
233	take_bool(3 == 1);
234}
235
236void
237fold_ne(void)
238{
239	take_bool(1 != 3);
240	take_bool(3 != 1);
241}
242
243void
244fold_bitand(void)
245{
246	take_bool(1 & 3);
247	take_bool(3 & 1);
248}
249
250void
251fold_bitxor(void)
252{
253	take_bool(1 ^ 3);
254	take_bool(3 ^ 1);
255}
256
257void
258fold_bitor(void)
259{
260	take_bool(1 | 3);
261	take_bool(3 | 1);
262}
263
264/*
265 * The following expression originated in vndcompress.c 1.29 from 2017-07-29,
266 * where line 310 contained a seemingly harmless compile-time assertion that
267 * expanded to a real monster expression.
268 *
269 * __CTASSERT(MUL_OK(uint64_t, MAX_N_BLOCKS, MAX_BLOCKSIZE));
270 *
271 * Before tree.c 1.345 from 2021-08-22, lint wrongly assumed that the result
272 * of all binary operators were the common arithmetic type, but that was
273 * wrong for the comparison operators.  The expression '1ULL < 2ULL' does not
274 * have type 'unsigned long long' but 'int' in default mode, or '_Bool' in
275 * strict bool mode.
276 */
277struct ctassert5_struct {
278	unsigned int member:
279	    /*CONSTCOND*/
280	    0xfffffffeU
281	    <=
282		((1ULL << 63) + 1 < 1 ? ~(1ULL << 63) : ~0ULL) / 0xfffffe00U
283		? 1
284		: -1;
285};
286
287/*
288 * Since Makefile.inc 1.21 from 2022-04-08 (which added -ftrapv) and before
289 * tree.c 1.436 from 2022-04-20, lint crashed with an integer overflow when
290 * calculating '-(uint64_t)INT64_MIN' in val_t.u.integer.
291 */
292void
293unary_minus_overflow(unsigned long long val)
294{
295	/* expect+1: warning: operator '-' produces integer overflow [141] */
296	if (val > -(unsigned long long)(-0x7fffffffffffffffL - 1))
297		return;
298}
299