1 /*
2 * Copyright 2016 The WebRTC Project Authors. All rights reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "rtc_base/numerics/safe_compare.h"
12
13 #include <limits>
14
15 #include "test/gtest.h"
16
17 namespace rtc {
18
19 namespace {
20
21 constexpr std::uintmax_t umax = std::numeric_limits<std::uintmax_t>::max();
22 constexpr std::intmax_t imin = std::numeric_limits<std::intmax_t>::min();
23 constexpr std::intmax_t m1 = -1;
24
25 // m1 and umax have the same representation because we use 2's complement
26 // arithmetic, so naive casting will confuse them.
27 static_assert(static_cast<std::uintmax_t>(m1) == umax, "");
28 static_assert(m1 == static_cast<std::intmax_t>(umax), "");
29
30 static const std::pair<int, int> p1(1, 1);
31 static const std::pair<int, int> p2(1, 2);
32
33 } // namespace
34
35 // clang-format off
36
37 // These functions aren't used in the tests, but it's useful to look at the
38 // compiler output for them, and verify that (1) the same-signedness *Safe
39 // functions result in exactly the same code as their *Ref counterparts, and
40 // that (2) the mixed-signedness *Safe functions have just a few extra
41 // arithmetic and logic instructions (but no extra control flow instructions).
TestLessThanRef(int a,int b)42 bool TestLessThanRef( int a, int b) { return a < b; }
TestLessThanRef(unsigned a,unsigned b)43 bool TestLessThanRef( unsigned a, unsigned b) { return a < b; }
TestLessThanSafe(int a,int b)44 bool TestLessThanSafe( int a, int b) { return SafeLt(a, b); }
TestLessThanSafe(unsigned a,unsigned b)45 bool TestLessThanSafe(unsigned a, unsigned b) { return SafeLt(a, b); }
TestLessThanSafe(unsigned a,int b)46 bool TestLessThanSafe(unsigned a, int b) { return SafeLt(a, b); }
TestLessThanSafe(int a,unsigned b)47 bool TestLessThanSafe( int a, unsigned b) { return SafeLt(a, b); }
48
49 // For these, we expect the *Ref and *Safe functions to result in identical
50 // code, except for the ones that compare a signed variable with an unsigned
51 // constant; in that case, the *Ref function does an unsigned comparison (fast
52 // but incorrect) and the *Safe function spends a few extra instructions on
53 // doing it right.
TestLessThan17Ref(int a)54 bool TestLessThan17Ref( int a) { return a < 17; }
TestLessThan17Ref(unsigned a)55 bool TestLessThan17Ref( unsigned a) { return a < 17; }
TestLessThan17uRef(int a)56 bool TestLessThan17uRef( int a) { return static_cast<unsigned>(a) < 17u; }
TestLessThan17uRef(unsigned a)57 bool TestLessThan17uRef( unsigned a) { return a < 17u; }
TestLessThan17Safe(int a)58 bool TestLessThan17Safe( int a) { return SafeLt(a, 17); }
TestLessThan17Safe(unsigned a)59 bool TestLessThan17Safe( unsigned a) { return SafeLt(a, 17); }
TestLessThan17uSafe(int a)60 bool TestLessThan17uSafe( int a) { return SafeLt(a, 17u); }
TestLessThan17uSafe(unsigned a)61 bool TestLessThan17uSafe(unsigned a) { return SafeLt(a, 17u); }
62
63 // Cases where we can't convert to a larger signed type.
TestLessThanMax(intmax_t a,uintmax_t b)64 bool TestLessThanMax( intmax_t a, uintmax_t b) { return SafeLt(a, b); }
TestLessThanMax(uintmax_t a,intmax_t b)65 bool TestLessThanMax(uintmax_t a, intmax_t b) { return SafeLt(a, b); }
TestLessThanMax17u(intmax_t a)66 bool TestLessThanMax17u( intmax_t a) { return SafeLt(a, uintmax_t{17}); }
TestLessThanMax17(uintmax_t a)67 bool TestLessThanMax17( uintmax_t a) { return SafeLt(a, intmax_t{17}); }
68
69 // Cases where the compiler should be able to compute the result at compile
70 // time.
TestLessThanConst1()71 bool TestLessThanConst1() { return SafeLt( -1, 1); }
TestLessThanConst2()72 bool TestLessThanConst2() { return SafeLt( m1, umax); }
TestLessThanConst3()73 bool TestLessThanConst3() { return SafeLt(umax, imin); }
TestLessThanConst4(unsigned a)74 bool TestLessThanConst4(unsigned a) { return SafeLt( a, -1); }
TestLessThanConst5(unsigned a)75 bool TestLessThanConst5(unsigned a) { return SafeLt(-1, a); }
TestLessThanConst6(unsigned a)76 bool TestLessThanConst6(unsigned a) { return SafeLt( a, a); }
77
78 // clang-format on
79
TEST(SafeCmpTest,Eq)80 TEST(SafeCmpTest, Eq) {
81 static_assert(!SafeEq(-1, 2), "");
82 static_assert(!SafeEq(-1, 2u), "");
83 static_assert(!SafeEq(2, -1), "");
84 static_assert(!SafeEq(2u, -1), "");
85
86 static_assert(!SafeEq(1, 2), "");
87 static_assert(!SafeEq(1, 2u), "");
88 static_assert(!SafeEq(1u, 2), "");
89 static_assert(!SafeEq(1u, 2u), "");
90 static_assert(!SafeEq(2, 1), "");
91 static_assert(!SafeEq(2, 1u), "");
92 static_assert(!SafeEq(2u, 1), "");
93 static_assert(!SafeEq(2u, 1u), "");
94
95 static_assert(SafeEq(2, 2), "");
96 static_assert(SafeEq(2, 2u), "");
97 static_assert(SafeEq(2u, 2), "");
98 static_assert(SafeEq(2u, 2u), "");
99
100 static_assert(SafeEq(imin, imin), "");
101 static_assert(!SafeEq(imin, umax), "");
102 static_assert(!SafeEq(umax, imin), "");
103 static_assert(SafeEq(umax, umax), "");
104
105 static_assert(SafeEq(m1, m1), "");
106 static_assert(!SafeEq(m1, umax), "");
107 static_assert(!SafeEq(umax, m1), "");
108 static_assert(SafeEq(umax, umax), "");
109
110 static_assert(!SafeEq(1, 2), "");
111 static_assert(!SafeEq(1, 2.0), "");
112 static_assert(!SafeEq(1.0, 2), "");
113 static_assert(!SafeEq(1.0, 2.0), "");
114 static_assert(!SafeEq(2, 1), "");
115 static_assert(!SafeEq(2, 1.0), "");
116 static_assert(!SafeEq(2.0, 1), "");
117 static_assert(!SafeEq(2.0, 1.0), "");
118
119 static_assert(SafeEq(2, 2), "");
120 static_assert(SafeEq(2, 2.0), "");
121 static_assert(SafeEq(2.0, 2), "");
122 static_assert(SafeEq(2.0, 2.0), "");
123
124 EXPECT_TRUE(SafeEq(p1, p1));
125 EXPECT_FALSE(SafeEq(p1, p2));
126 EXPECT_FALSE(SafeEq(p2, p1));
127 EXPECT_TRUE(SafeEq(p2, p2));
128 }
129
TEST(SafeCmpTest,Ne)130 TEST(SafeCmpTest, Ne) {
131 static_assert(SafeNe(-1, 2), "");
132 static_assert(SafeNe(-1, 2u), "");
133 static_assert(SafeNe(2, -1), "");
134 static_assert(SafeNe(2u, -1), "");
135
136 static_assert(SafeNe(1, 2), "");
137 static_assert(SafeNe(1, 2u), "");
138 static_assert(SafeNe(1u, 2), "");
139 static_assert(SafeNe(1u, 2u), "");
140 static_assert(SafeNe(2, 1), "");
141 static_assert(SafeNe(2, 1u), "");
142 static_assert(SafeNe(2u, 1), "");
143 static_assert(SafeNe(2u, 1u), "");
144
145 static_assert(!SafeNe(2, 2), "");
146 static_assert(!SafeNe(2, 2u), "");
147 static_assert(!SafeNe(2u, 2), "");
148 static_assert(!SafeNe(2u, 2u), "");
149
150 static_assert(!SafeNe(imin, imin), "");
151 static_assert(SafeNe(imin, umax), "");
152 static_assert(SafeNe(umax, imin), "");
153 static_assert(!SafeNe(umax, umax), "");
154
155 static_assert(!SafeNe(m1, m1), "");
156 static_assert(SafeNe(m1, umax), "");
157 static_assert(SafeNe(umax, m1), "");
158 static_assert(!SafeNe(umax, umax), "");
159
160 static_assert(SafeNe(1, 2), "");
161 static_assert(SafeNe(1, 2.0), "");
162 static_assert(SafeNe(1.0, 2), "");
163 static_assert(SafeNe(1.0, 2.0), "");
164 static_assert(SafeNe(2, 1), "");
165 static_assert(SafeNe(2, 1.0), "");
166 static_assert(SafeNe(2.0, 1), "");
167 static_assert(SafeNe(2.0, 1.0), "");
168
169 static_assert(!SafeNe(2, 2), "");
170 static_assert(!SafeNe(2, 2.0), "");
171 static_assert(!SafeNe(2.0, 2), "");
172 static_assert(!SafeNe(2.0, 2.0), "");
173
174 EXPECT_FALSE(SafeNe(p1, p1));
175 EXPECT_TRUE(SafeNe(p1, p2));
176 EXPECT_TRUE(SafeNe(p2, p1));
177 EXPECT_FALSE(SafeNe(p2, p2));
178 }
179
TEST(SafeCmpTest,Lt)180 TEST(SafeCmpTest, Lt) {
181 static_assert(SafeLt(-1, 2), "");
182 static_assert(SafeLt(-1, 2u), "");
183 static_assert(!SafeLt(2, -1), "");
184 static_assert(!SafeLt(2u, -1), "");
185
186 static_assert(SafeLt(1, 2), "");
187 static_assert(SafeLt(1, 2u), "");
188 static_assert(SafeLt(1u, 2), "");
189 static_assert(SafeLt(1u, 2u), "");
190 static_assert(!SafeLt(2, 1), "");
191 static_assert(!SafeLt(2, 1u), "");
192 static_assert(!SafeLt(2u, 1), "");
193 static_assert(!SafeLt(2u, 1u), "");
194
195 static_assert(!SafeLt(2, 2), "");
196 static_assert(!SafeLt(2, 2u), "");
197 static_assert(!SafeLt(2u, 2), "");
198 static_assert(!SafeLt(2u, 2u), "");
199
200 static_assert(!SafeLt(imin, imin), "");
201 static_assert(SafeLt(imin, umax), "");
202 static_assert(!SafeLt(umax, imin), "");
203 static_assert(!SafeLt(umax, umax), "");
204
205 static_assert(!SafeLt(m1, m1), "");
206 static_assert(SafeLt(m1, umax), "");
207 static_assert(!SafeLt(umax, m1), "");
208 static_assert(!SafeLt(umax, umax), "");
209
210 static_assert(SafeLt(1, 2), "");
211 static_assert(SafeLt(1, 2.0), "");
212 static_assert(SafeLt(1.0, 2), "");
213 static_assert(SafeLt(1.0, 2.0), "");
214 static_assert(!SafeLt(2, 1), "");
215 static_assert(!SafeLt(2, 1.0), "");
216 static_assert(!SafeLt(2.0, 1), "");
217 static_assert(!SafeLt(2.0, 1.0), "");
218
219 static_assert(!SafeLt(2, 2), "");
220 static_assert(!SafeLt(2, 2.0), "");
221 static_assert(!SafeLt(2.0, 2), "");
222 static_assert(!SafeLt(2.0, 2.0), "");
223
224 EXPECT_FALSE(SafeLt(p1, p1));
225 EXPECT_TRUE(SafeLt(p1, p2));
226 EXPECT_FALSE(SafeLt(p2, p1));
227 EXPECT_FALSE(SafeLt(p2, p2));
228 }
229
TEST(SafeCmpTest,Le)230 TEST(SafeCmpTest, Le) {
231 static_assert(SafeLe(-1, 2), "");
232 static_assert(SafeLe(-1, 2u), "");
233 static_assert(!SafeLe(2, -1), "");
234 static_assert(!SafeLe(2u, -1), "");
235
236 static_assert(SafeLe(1, 2), "");
237 static_assert(SafeLe(1, 2u), "");
238 static_assert(SafeLe(1u, 2), "");
239 static_assert(SafeLe(1u, 2u), "");
240 static_assert(!SafeLe(2, 1), "");
241 static_assert(!SafeLe(2, 1u), "");
242 static_assert(!SafeLe(2u, 1), "");
243 static_assert(!SafeLe(2u, 1u), "");
244
245 static_assert(SafeLe(2, 2), "");
246 static_assert(SafeLe(2, 2u), "");
247 static_assert(SafeLe(2u, 2), "");
248 static_assert(SafeLe(2u, 2u), "");
249
250 static_assert(SafeLe(imin, imin), "");
251 static_assert(SafeLe(imin, umax), "");
252 static_assert(!SafeLe(umax, imin), "");
253 static_assert(SafeLe(umax, umax), "");
254
255 static_assert(SafeLe(m1, m1), "");
256 static_assert(SafeLe(m1, umax), "");
257 static_assert(!SafeLe(umax, m1), "");
258 static_assert(SafeLe(umax, umax), "");
259
260 static_assert(SafeLe(1, 2), "");
261 static_assert(SafeLe(1, 2.0), "");
262 static_assert(SafeLe(1.0, 2), "");
263 static_assert(SafeLe(1.0, 2.0), "");
264 static_assert(!SafeLe(2, 1), "");
265 static_assert(!SafeLe(2, 1.0), "");
266 static_assert(!SafeLe(2.0, 1), "");
267 static_assert(!SafeLe(2.0, 1.0), "");
268
269 static_assert(SafeLe(2, 2), "");
270 static_assert(SafeLe(2, 2.0), "");
271 static_assert(SafeLe(2.0, 2), "");
272 static_assert(SafeLe(2.0, 2.0), "");
273
274 EXPECT_TRUE(SafeLe(p1, p1));
275 EXPECT_TRUE(SafeLe(p1, p2));
276 EXPECT_FALSE(SafeLe(p2, p1));
277 EXPECT_TRUE(SafeLe(p2, p2));
278 }
279
TEST(SafeCmpTest,Gt)280 TEST(SafeCmpTest, Gt) {
281 static_assert(!SafeGt(-1, 2), "");
282 static_assert(!SafeGt(-1, 2u), "");
283 static_assert(SafeGt(2, -1), "");
284 static_assert(SafeGt(2u, -1), "");
285
286 static_assert(!SafeGt(1, 2), "");
287 static_assert(!SafeGt(1, 2u), "");
288 static_assert(!SafeGt(1u, 2), "");
289 static_assert(!SafeGt(1u, 2u), "");
290 static_assert(SafeGt(2, 1), "");
291 static_assert(SafeGt(2, 1u), "");
292 static_assert(SafeGt(2u, 1), "");
293 static_assert(SafeGt(2u, 1u), "");
294
295 static_assert(!SafeGt(2, 2), "");
296 static_assert(!SafeGt(2, 2u), "");
297 static_assert(!SafeGt(2u, 2), "");
298 static_assert(!SafeGt(2u, 2u), "");
299
300 static_assert(!SafeGt(imin, imin), "");
301 static_assert(!SafeGt(imin, umax), "");
302 static_assert(SafeGt(umax, imin), "");
303 static_assert(!SafeGt(umax, umax), "");
304
305 static_assert(!SafeGt(m1, m1), "");
306 static_assert(!SafeGt(m1, umax), "");
307 static_assert(SafeGt(umax, m1), "");
308 static_assert(!SafeGt(umax, umax), "");
309
310 static_assert(!SafeGt(1, 2), "");
311 static_assert(!SafeGt(1, 2.0), "");
312 static_assert(!SafeGt(1.0, 2), "");
313 static_assert(!SafeGt(1.0, 2.0), "");
314 static_assert(SafeGt(2, 1), "");
315 static_assert(SafeGt(2, 1.0), "");
316 static_assert(SafeGt(2.0, 1), "");
317 static_assert(SafeGt(2.0, 1.0), "");
318
319 static_assert(!SafeGt(2, 2), "");
320 static_assert(!SafeGt(2, 2.0), "");
321 static_assert(!SafeGt(2.0, 2), "");
322 static_assert(!SafeGt(2.0, 2.0), "");
323
324 EXPECT_FALSE(SafeGt(p1, p1));
325 EXPECT_FALSE(SafeGt(p1, p2));
326 EXPECT_TRUE(SafeGt(p2, p1));
327 EXPECT_FALSE(SafeGt(p2, p2));
328 }
329
TEST(SafeCmpTest,Ge)330 TEST(SafeCmpTest, Ge) {
331 static_assert(!SafeGe(-1, 2), "");
332 static_assert(!SafeGe(-1, 2u), "");
333 static_assert(SafeGe(2, -1), "");
334 static_assert(SafeGe(2u, -1), "");
335
336 static_assert(!SafeGe(1, 2), "");
337 static_assert(!SafeGe(1, 2u), "");
338 static_assert(!SafeGe(1u, 2), "");
339 static_assert(!SafeGe(1u, 2u), "");
340 static_assert(SafeGe(2, 1), "");
341 static_assert(SafeGe(2, 1u), "");
342 static_assert(SafeGe(2u, 1), "");
343 static_assert(SafeGe(2u, 1u), "");
344
345 static_assert(SafeGe(2, 2), "");
346 static_assert(SafeGe(2, 2u), "");
347 static_assert(SafeGe(2u, 2), "");
348 static_assert(SafeGe(2u, 2u), "");
349
350 static_assert(SafeGe(imin, imin), "");
351 static_assert(!SafeGe(imin, umax), "");
352 static_assert(SafeGe(umax, imin), "");
353 static_assert(SafeGe(umax, umax), "");
354
355 static_assert(SafeGe(m1, m1), "");
356 static_assert(!SafeGe(m1, umax), "");
357 static_assert(SafeGe(umax, m1), "");
358 static_assert(SafeGe(umax, umax), "");
359
360 static_assert(!SafeGe(1, 2), "");
361 static_assert(!SafeGe(1, 2.0), "");
362 static_assert(!SafeGe(1.0, 2), "");
363 static_assert(!SafeGe(1.0, 2.0), "");
364 static_assert(SafeGe(2, 1), "");
365 static_assert(SafeGe(2, 1.0), "");
366 static_assert(SafeGe(2.0, 1), "");
367 static_assert(SafeGe(2.0, 1.0), "");
368
369 static_assert(SafeGe(2, 2), "");
370 static_assert(SafeGe(2, 2.0), "");
371 static_assert(SafeGe(2.0, 2), "");
372 static_assert(SafeGe(2.0, 2.0), "");
373
374 EXPECT_TRUE(SafeGe(p1, p1));
375 EXPECT_FALSE(SafeGe(p1, p2));
376 EXPECT_TRUE(SafeGe(p2, p1));
377 EXPECT_TRUE(SafeGe(p2, p2));
378 }
379
TEST(SafeCmpTest,Enum)380 TEST(SafeCmpTest, Enum) {
381 enum E1 { e1 = 13 };
382 enum { e2 = 13 };
383 enum E3 : unsigned { e3 = 13 };
384 enum : unsigned { e4 = 13 };
385 static_assert(SafeEq(13, e1), "");
386 static_assert(SafeEq(13u, e1), "");
387 static_assert(SafeEq(13, e2), "");
388 static_assert(SafeEq(13u, e2), "");
389 static_assert(SafeEq(13, e3), "");
390 static_assert(SafeEq(13u, e3), "");
391 static_assert(SafeEq(13, e4), "");
392 static_assert(SafeEq(13u, e4), "");
393 }
394
395 } // namespace rtc
396