Error for `tgmath` functions (if argument contains a pointer dereference?)

[michael-schwarz]

During goblint/bench#10 (after a patch to ignore omp pragmas), I discovered that type-generic mathematics is still mishandled in certain circumstances, namely if a pointer dereference occurs inside the expression.

A reduce example is:

#include<tgmath.h>
typedef struct loc_t
{
  long nloc;
} loc_t;


void fun(const loc_t* loc) {
    long l;
    int n0 =(int)sqrt(l); // works
    int n1 =(int)sqrt(loc->nloc); // fails
}


int main() {
  loc_t loc;
  loc_t* ptr = &loc;
  fun(ptr);
}

This produces errors for the second invocation of sqrt:

2.c:11: Warning: MEMBEROFPTR in constant
2.c:11: Error: cabs2cil/castTo: illegal cast  double  -> void 

2.c:11: Error: cabs2cil/castTo: illegal cast  _Complex double  -> void 

2.c:11: Warning: MEMBEROFPTR in constant
2.c:11: Error: cabs2cil/castTo: illegal cast  float  -> void 

2.c:11: Error: cabs2cil/castTo: illegal cast  _Complex float  -> void 

2.c:11: Warning: MEMBEROFPTR in constant
2.c:11: Error: cabs2cil/castTo: illegal cast  long double  -> void 

2.c:11: Error: cabs2cil/castTo: illegal cast  _Complex long double  -> void 

Error: There were errors during merging

Fatal error: exception Errormsg.Error

It works fine with GCC though.