libc/test/src/setjmp/setjmp_test.cpp

   1 //===-- Unittests for setjmp and longjmp ----------------------------------===//
   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/setjmp/longjmp.h"
  10 #include "src/setjmp/setjmp_impl.h"
  11 #include "test/UnitTest/Test.h"
  12
  13 constexpr int MAX_LOOP = 123;
  14 int longjmp_called = 0;
  15
  16 void jump_back(jmp_buf buf, int n) {
  17   longjmp_called++;
  18   LIBC_NAMESPACE::longjmp(buf, n); // Will return |n| out of setjmp
  19 }
  20
  21 TEST(LlvmLibcSetJmpTest, SetAndJumpBack) {
  22   jmp_buf buf;
  23   longjmp_called = 0;
  24
  25   // Local variables in setjmp scope should be declared volatile.
  26   volatile int n = 0;
  27   // The first time setjmp is called, it should return 0.
  28   // Subsequent calls will return the value passed to jump_back below.
  29   if (LIBC_NAMESPACE::setjmp(buf) <= MAX_LOOP) {
  30     ++n;
  31     jump_back(buf, n);
  32   }
  33   ASSERT_EQ(longjmp_called, n);
  34   ASSERT_EQ(n, MAX_LOOP + 1);
  35 }
  36
  37 TEST(LlvmLibcSetJmpTest, SetAndJumpBackValOne) {
  38   jmp_buf buf;
  39   longjmp_called = 0;
  40
  41   int val = LIBC_NAMESPACE::setjmp(buf);
  42   if (val == 0)
  43     jump_back(buf, val);
  44
  45   ASSERT_EQ(longjmp_called, 1);
  46   ASSERT_EQ(val, 1);
  47 }