Thread: Detailed asserts

Greetings,

Until now both clang/gcc compilers do not show detailed/verbose info for asserts. Consider:

Code:

// detailed asserts


#include <stdio.h>
#include <stdlib.h>
#include <assert.h>


int main(void)
{
    int a=1;
    int b=2;
    assert(a==b);
    
    return 0;
}

Output:

Code:

clang:
a.out: assert.c:11: int main(void): Assertion `a==b' failed.
Aborted (core dumped)

gcc:
a.out: assert.c:11: main: Assertion `a==b' failed.
Aborted (core dumped)

I want such addition:

Code:

a is 1
b is 2

or:
(1==2) failed

Considering CUnit testing library:

Code:

// Detailed CUnit asserts


// http://cunit.sourceforge.net/


#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <stdnoreturn.h>


#include <CUnit/CUnit.h>
#include <CUnit/Basic.h>
#include <CUnit/Console.h>


int maxi(int i1, int i2)
{
    return (i1 > i2) ? -i1 : -i2; // wrong
}


void test_maxi(void)
{ 
    CU_ASSERT_EQUAL(maxi(0,2) , 2);
    CU_ASSERT_EQUAL(maxi(-1,-2) , -1);
    CU_ASSERT_EQUAL(maxi(2,2) , 2);
}


int main(void)
{
    CU_initialize_registry();


    CU_pSuite suite1 = CU_add_suite("suite1", NULL, NULL);


    CU_add_test(suite1, "test_maxi", test_maxi);


    CU_basic_set_mode(CU_BRM_VERBOSE); 


    //CU_automated_run_tests();
    CU_basic_run_tests();


    CU_cleanup_registry();


    return 0;
}

Output:

Code:

     CUnit - A unit testing framework for C - Version 2.1-3
     http://cunit.sourceforge.net/




Suite: suite1
  Test: test_maxi ...FAILED
    1. cu_assert.c:21  - CU_ASSERT_EQUAL(maxi(0,2),2)
    2. cu_assert.c:22  - CU_ASSERT_EQUAL(maxi(-1,-2),-1)
    3. cu_assert.c:23  - CU_ASSERT_EQUAL(maxi(2,2),2)


Run Summary:    Type  Total    Ran Passed Failed Inactive
              suites      1      1    n/a      0        0
               tests      1      1      0      1        0
             asserts      3      3      0      3      n/a


Elapsed time =    0.000 seconds

I want computed values of maxi too. But they are not given in the above output. Some other testing libraries do it.

I imagine it would be difficult if not impossible for the assert function/macro to do such a thing. You could do something like this, though:

Code:

assert(a == b || (fprintf(stderr, "a is %d\nb is %d\n", a, b), 0));

which should print out the "a is 1" and "b is 2" lines before the program is aborted. You could even wrap the whole (fprintf(...), 0) expression in a macro to make the assertion output look cleaner.