Example: provenance_equality_uintptr_t_global_xy.c

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    #include <stdio.h>
    #include <inttypes.h> 
    int x=1, y=2;
    int main() {
      uintptr_t p = (uintptr_t)(&x + 1);
      uintptr_t q = (uintptr_t)&y;
      printf("Addresses: p=%" PRIxPTR " q=%" PRIxPTR "\n",
             p,q);
      _Bool b = (p==q);
      // can this be false even with identical addresses?
      printf("(p==q) = %s\n", b?"true":"false");
      return 0;
    }

Experimental data (what does this mean?)

cerberus-concrete-PVI
 
Addresses: p=3c q=3c
(p==q) = true

cerberus-concrete-PNVI
 
Addresses: p=3c q=3c
(p==q) = true

gcc-8.1-O0
 
Addresses: p=6009b4 q=6009b4
(p==q) = true

gcc-8.1-O2
 
Addresses: p=6009a0 q=600998
(p==q) = false

gcc-8.1-O3
 
Addresses: p=6009a0 q=600998
(p==q) = false

gcc-8.1-O2-no-strict-aliasing
 
Addresses: p=6009a0 q=600998
(p==q) = false

gcc-8.1-O3-no-strict-aliasing
 
Addresses: p=6009a0 q=600998
(p==q) = false

clang-6.0-O0
 
Addresses: p=60103c q=60103c
(p==q) = true

clang-6.0-O2
 
Addresses: p=60103c q=60103c
(p==q) = true

clang-6.0-O3
 
Addresses: p=60103c q=60103c
(p==q) = true

clang-6.0-O2-no-strict-aliasing
 
Addresses: p=60103c q=60103c
(p==q) = true

clang-6.0-O3-no-strict-aliasing
 
Addresses: p=60103c q=60103c
(p==q) = true

clang-6.0-UBSAN
 
Addresses: p=631b54 q=631b54
(p==q) = true

clang-6.0-ASAN
 
Addresses: p=716b64 q=716ba0
(p==q) = false

clang-6.0-MSAN
 
Addresses: p=6b7af4 q=6b7af4
(p==q) = true

icc-19-O0
 
Addresses: p=600ae4 q=600ae4
(p==q) = true

icc-19-O2
 
Addresses: p=6046c4 q=6046c4
(p==q) = true

icc-19-O3
 
Addresses: p=6046c4 q=6046c4
(p==q) = true

icc-19-O2-no-strict-aliasing
 
Addresses: p=6046c4 q=6046c4
(p==q) = true

icc-19-O3-no-strict-aliasing
 
Addresses: p=6046c4 q=6046c4
(p==q) = true

compcert-3.4
 
Addresses: p=60103c q=60103c
(p==q) = true

compcert-3.4-O
 
Addresses: p=60103c q=60103c
(p==q) = true

kcc-1.0
 
Addresses: p=0 q=0
(p==q) = true
Printing an unspecified value:
      > in printf at provenance_equality_uintptr_t_global_xy.c:7:3
        in main at provenance_equality_uintptr_t_global_xy.c:7:3

    Unspecified value or behavior (USP-STDIO2):
        see C11 section 7.21.6.1:8 http://rvdoc.org/C11/7.21.6.1

Comparison of unspecified value:
      > in main at provenance_equality_uintptr_t_global_xy.c:11:3

    Unspecified value or behavior (USP-CERL7):
        see C11 section 6.5.9 http://rvdoc.org/C11/6.5.9
        see MISRA-C section 8.1:3 http://rvdoc.org/MISRA-C/8.1