Example: provenance_equality_global_xy.c

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    #include <stdio.h>
    #include <string.h> 
    int x=1, y=2;
    int main() {
      int *p = &x + 1;
      int *q = &y;
      printf("Addresses: p=%p q=%p\n",(void*)p,(void*)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-plain EXECUTION 0 (exit = Specified(0)):
Addresses: p=(@0, 0xfffffffc) q=(@1, 0xfffffff4)
(p==q) = false

EXECUTION 1 (exit = Specified(0)):
Addresses: p=(@0, 0xfffffffc) q=(@1, 0xfffffff4)
(p==q) = false


cerberus-concrete-PVI-ae EXECUTION 0 (exit = Specified(0)):
Addresses: p=(@0, 0xfffffffc) q=(@1, 0xfffffff4)
(p==q) = false

EXECUTION 1 (exit = Specified(0)):
Addresses: p=(@0, 0xfffffffc) q=(@1, 0xfffffff4)
(p==q) = false


cerberus-concrete-PVI-ae-udi EXECUTION 0 (exit = Specified(0)):
Addresses: p=(@0, 0xfffffffc) q=(@1, 0xfffffff4)
(p==q) = false

EXECUTION 1 (exit = Specified(0)):
Addresses: p=(@0, 0xfffffffc) q=(@1, 0xfffffff4)
(p==q) = false


gcc-8.3-O0 Addresses: p=0x10000101c q=0x10000101c
(p==q) = true


gcc-8.3-O2 Addresses: p=0x100001020 q=0x100001018
(p==q) = false


gcc-8.3-O3 Addresses: p=0x100001020 q=0x100001018
(p==q) = false


gcc-8.3-O2-no-strict-aliasing Addresses: p=0x100001020 q=0x100001018
(p==q) = false


gcc-8.3-O3-no-strict-aliasing Addresses: p=0x100001020 q=0x100001018
(p==q) = false


clang-7.0.1-O0 Addresses: p=0x10000101c q=0x10000101c
(p==q) = true


clang-7.0.1-O2 Addresses: p=0x10000101c q=0x10000101c
(p==q) = true


clang-7.0.1-O3 Addresses: p=0x10000101c q=0x10000101c
(p==q) = true


clang-7.0.1-O2-no-strict-aliasing Addresses: p=0x10000101c q=0x10000101c
(p==q) = true


clang-7.0.1-O3-no-strict-aliasing Addresses: p=0x10000101c q=0x10000101c
(p==q) = true


icc-19-O0 Addresses: p=0x600ae4 q=0x600ae4
(p==q) = true


icc-19-O2 Addresses: p=0x6046c4 q=0x6046c4
(p==q) = true


icc-19-O3 Addresses: p=0x6046c4 q=0x6046c4
(p==q) = true


icc-19-O2-no-strict-aliasing Addresses: p=0x6046c4 q=0x6046c4
(p==q) = true


icc-19-O3-no-strict-aliasing Addresses: p=0x6046c4 q=0x6046c4
(p==q) = true