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path: root/test/Expr/ReadExprConsistency.c
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// RUN: %clang %s -emit-llvm -g -c -o %t.bc
// RUN: rm -rf %t.klee-out
// RUN: %klee --output-dir=%t.klee-out --exit-on-error %t.bc 2>%t.log
// RUN: cat %t.log | FileCheck %s
#include "klee/klee.h"
#include <assert.h>
#include <stdio.h>

/*
This tests checks ensures that only relevant updates are present when doing
concrete reads. If they are not, there can be situations where ReadExpr are
in inconsistent state and depend on ordering of other operations.

See
https://github.com/klee/klee/issues/921
https://github.com/klee/klee/pull/1061
*/

int main() {
	char  arr[3];
  char symbolic;
  klee_make_symbolic(&symbolic, sizeof(symbolic), "symbolic");
  klee_assume(symbolic >= 0 & symbolic < 3); 
  klee_make_symbolic(arr, sizeof(arr), "arr");
  
  
  char a = arr[2];  // (ReadExpr 2 arr)
  // CHECK: arr[2]:(SExt w32 (Read w8 2 arr))
  klee_print_expr("arr[2]", arr[2]);
  arr[1] = 0;
  char b = arr[symbolic];  // (ReadExpr symbolic [1=0]@arr)
  // CHECK: arr[2]:(SExt w32 (Read w8 2 arr))
  // CHECK-NOT: arr[2]:(SExt w32 (Read w8 2 [1=0]@arr))
  klee_print_expr("arr[2]", arr[2]);
  
  if(a == b) printf("Equal!\n");
  else printf("Not Equal!\n");
  return 0;
}