1  /* Test the "verify" module.
       2  
       3     Copyright (C) 2005, 2009-2022 Free Software Foundation, Inc.
       4  
       5     This program is free software: you can redistribute it and/or modify
       6     it under the terms of the GNU General Public License as published by
       7     the Free Software Foundation, either version 3 of the License, or
       8     (at your option) any later version.
       9  
      10     This program is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      13     GNU General Public License for more details.
      14  
      15     You should have received a copy of the GNU General Public License
      16     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  /* Written by Bruno Haible.  */
      19  
      20  #include <config.h>
      21  
      22  #include "verify.h"
      23  
      24  #ifndef EXP_FAIL
      25  # define EXP_FAIL 0
      26  #endif
      27  
      28  /* ======================= Test verify, verify_expr ======================= */
      29  
      30  int gx;
      31  enum { A, B, C };
      32  
      33  #if EXP_FAIL == 1
      34  verify (gx >= 0);                 /* should give ERROR: non-constant expression */
      35  #endif
      36  verify (C == 2);                  /* should be ok */
      37  #if EXP_FAIL == 2
      38  verify (1 + 1 == 3);              /* should give ERROR */
      39  #endif
      40  verify (1 == 1); verify (1 == 1); /* should be ok */
      41  
      42  enum
      43  {
      44    item = verify_expr (1 == 1, 10 * 0 + 17) /* should be ok */
      45  };
      46  
      47  static int
      48  function (int n)
      49  {
      50  #if EXP_FAIL == 3
      51    verify (n >= 0);                  /* should give ERROR: non-constant expression */
      52  #endif
      53    verify (C == 2);                  /* should be ok */
      54  #if EXP_FAIL == 4
      55    verify (1 + 1 == 3);              /* should give ERROR */
      56  #endif
      57    verify (1 == 1); verify (1 == 1); /* should be ok */
      58  
      59    if (n)
      60      return ((void) verify_expr (1 == 1, 1), verify_expr (1 == 1, 8)); /* should be ok */
      61  #if EXP_FAIL == 5
      62    return verify_expr (1 == 2, 5); /* should give ERROR */
      63  #endif
      64    return 0;
      65  }
      66  
      67  /* ============================== Test assume ============================== */
      68  
      69  static int
      70  f (int a)
      71  {
      72    return a;
      73  }
      74  
      75  typedef struct { unsigned int context : 4; unsigned int halt : 1; } state;
      76  
      77  void test_assume_expressions (state *s);
      78  int test_assume_optimization (int x);
      79  _Noreturn void test_assume_noreturn (void);
      80  
      81  void
      82  test_assume_expressions (state *s)
      83  {
      84    /* Check that 'assume' accepts a function call, even of a non-const
      85       function.  */
      86    assume (f (1));
      87    /* Check that 'assume' accepts a bit-field expression.  */
      88    assume (s->halt);
      89  }
      90  
      91  int
      92  test_assume_optimization (int x)
      93  {
      94    /* Check that the compiler uses 'assume' for optimization.
      95       This function, when compiled with optimization, should have code
      96       equivalent to
      97         return x + 3;
      98       Use 'objdump --disassemble test-verify.o' to verify this.  */
      99    assume (x >= 4);
     100    return (x > 1 ? x + 3 : 2 * x + 10);
     101  }
     102  
     103  _Noreturn void
     104  test_assume_noreturn (void)
     105  {
     106    /* Check that the compiler's data-flow analysis recognizes 'assume (0)'.
     107       This function should not elicit a warning.  */
     108    assume (0);
     109  }
     110  
     111  /* ============================== Main ===================================== */
     112  int
     113  main (void)
     114  {
     115    state s = { 0, 1 };
     116    test_assume_expressions (&s);
     117    test_assume_optimization (5);
     118    return !(function (0) == 0 && function (1) == 8);
     119  }