1 //===-- Unittests for feraiseexcept with exceptions enabled ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/fenv/feclearexcept.h"
10 #include "src/fenv/feraiseexcept.h"
11 #include "src/fenv/fetestexcept.h"
12 
13 #include "src/__support/FPUtil/FEnvUtils.h"
14 #include "src/__support/FPUtil/FPExceptMatcher.h"
15 #include "utils/UnitTest/Test.h"
16 
17 #include <fenv.h>
18 #include <signal.h>
19 
20 // This test enables an exception and verifies that raising that exception
21 // triggers SIGFPE.
22 TEST(LlvmLibcExceptionStatusTest, RaiseAndCrash) {
23   // TODO: Install a floating point exception handler and verify that the
24   // the expected exception was raised. One will have to longjmp back from
25   // that exception handler, so such a testing can be done after we have
26   // longjmp implemented.
27 
28   int excepts[] = {FE_DIVBYZERO, FE_INVALID, FE_INEXACT, FE_OVERFLOW,
29                    FE_UNDERFLOW};
30 
31   // We '|' the individual exception flags instead of using FE_ALL_EXCEPT
32   // as it can include non-standard extensions. Note that we should be able
33   // to compile this file with headers from other libcs as well.
34   constexpr int allExcepts =
35       FE_DIVBYZERO | FE_INVALID | FE_INEXACT | FE_OVERFLOW | FE_UNDERFLOW;
36 
37   for (int e : excepts) {
38     __llvm_libc::fputil::disableExcept(FE_ALL_EXCEPT);
39     __llvm_libc::fputil::enableExcept(e);
40     ASSERT_EQ(__llvm_libc::feclearexcept(FE_ALL_EXCEPT), 0);
41     // Raising all exceptions except |e| should not call the
42     // SIGFPE handler. They should set the exception flag though,
43     // so we verify that. Since other exceptions like FE_DIVBYZERO
44     // can raise FE_INEXACT as well, we don't verify the other
45     // exception flags when FE_INEXACT is enabled.
46     if (e != FE_INEXACT) {
47       int others = allExcepts & ~e;
48       ASSERT_EQ(__llvm_libc::feraiseexcept(others), 0);
49       ASSERT_EQ(__llvm_libc::fetestexcept(others), others);
50     }
51 
52     ASSERT_RAISES_FP_EXCEPT([=] {
53       // In test frameworks like Fuchsia's zxtest, this translates to
54       // a death test which runs this closure in a different thread. So,
55       // we enable the exception again inside this closure so that the
56       // exception gets enabled for the thread running this closure.
57       __llvm_libc::fputil::enableExcept(e);
58       __llvm_libc::feraiseexcept(e);
59     });
60 
61     // Cleanup.
62     __llvm_libc::fputil::disableExcept(FE_ALL_EXCEPT);
63     ASSERT_EQ(__llvm_libc::feclearexcept(FE_ALL_EXCEPT), 0);
64   }
65 }
66