root/maint/gnulib/tests/test-verify.c

/* */

DEFINITIONS

1. function
2. f
3. test_assume_expressions
4. test_assume_optimization
5. test_assume_noreturn
6. main

   1 /* Test the "verify" module.
   2 
   3    Copyright (C) 2005, 2009-2021 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 }

/* */