Example: provenance_equality_uintptr_t_auto_xy.c

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    #include <stdio.h>
    #include <inttypes.h> 
    int main() {
      int x=1, y=2;
      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;
    }
[link to run test in Cerberus]

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=7fffffffe70c q=7fffffffe704
(p==q) = false
gcc-8.1-O2 Addresses: p=7fffffffe70c q=7fffffffe70c
(p==q) = true
gcc-8.1-O3 Addresses: p=7fffffffe70c q=7fffffffe70c
(p==q) = true
gcc-8.1-O2-no-strict-aliasing Addresses: p=7fffffffe6ec q=7fffffffe6ec
(p==q) = true
gcc-8.1-O3-no-strict-aliasing Addresses: p=7fffffffe6ec q=7fffffffe6ec
(p==q) = true
clang-6.0-O0 Addresses: p=7fffffffe71c q=7fffffffe714
(p==q) = false
clang-6.0-O2 Addresses: p=7fffffffe718 q=7fffffffe710
(p==q) = false
clang-6.0-O3 Addresses: p=7fffffffe718 q=7fffffffe710
(p==q) = false
clang-6.0-O2-no-strict-aliasing Addresses: p=7fffffffe6e8 q=7fffffffe6e0
(p==q) = false
clang-6.0-O3-no-strict-aliasing Addresses: p=7fffffffe6e8 q=7fffffffe6e0
(p==q) = false
clang-6.0-UBSAN Addresses: p=7fffffffe704 q=7fffffffe704
(p==q) = true
clang-6.0-ASAN Addresses: p=7fffffffe684 q=7fffffffe690
(p==q) = false
clang-6.0-MSAN Addresses: p=7fffffffe6e4 q=7fffffffe6e4
(p==q) = true
icc-19-O0 Addresses: p=7fffffffe6f8 q=7fffffffe6f8
(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=7fffffffe6dc q=7fffffffe6dc
(p==q) = true
compcert-3.4-O Addresses: p=7fffffffe6dc q=7fffffffe6dc
(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_auto_xy.c:7:3
in main at provenance_equality_uintptr_t_auto_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_auto_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