With struct containing arrays, option -unspecified-access is too strict

ID0002152: This issue was created automatically from Mantis Issue 2152. Further discussion may take place here.

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Id	Project	Category	View	Due Date	Updated
ID0002152	Frama-C	Kernel	public	2015-08-21	2015-08-21

Reporter	pascal	Assigned To	virgile	Resolution	open
Priority	normal	Severity	minor	Reproducibility	always
Platform	-	OS	-	OS Version	-
Product Version	-	Target Version	-	Fixed in Version	-

Description :

The program given below is correct, but:

$ frama-c -val t.c -unspecified-access ... t.c:4:[kernel] warning: Unspecified sequence with side effect: /* s.t[1] <- s.t / s.t[1] = (char)0; / s.t[2] <- s.t */ s.t[2] = s.t[1]; [value] Analyzing a complete application starting at main ... t.c:4:[kernel] warning: undefined multiple accesses in expression. assert \separated(&s.t[1], &s.t); [value] Recording results for main [value] done for function main t.c:4:[value] Assertion 'Value,separation' got final status invalid. ...

I expected this program would be accepted without a warning about multiple accesses in expressions.

Additional Information :

The struct is necessary for the bug to appear. With a toplevel array t, the assignment t[2] = t[1] = 0; does not cause a warning.

Steps To Reproduce :

struct s { char t[3]; } s;

int main() {
  s.t[2] = s.t[1] = 0;
  return 0;
}