I just started to learn stratego for C-transformation, and I had a problem with pp-c.

$ cat original.c

#include "stdio.h"

typedef struct A {
  int a;
} A;

int main(void) {
  A** app;
  A* ap;
  A a;
  a.a = 2;
  ap = &a;
  app = ≈
  printf("value=%i

", (*app)->a);
}

$ cat original.c | parse-c | pp-c > bug.c
$ cat bug.c

typedef struct A
        {
        int a;
        } A;
int main (void)
{
A * * app;
A * ap;
A a;
a.a = 2;
ap = &(a);
app = &(ap);
printf("value=%i

", *(app)->a);
}

The transformed code does not compile because of *(app)->a. Isn’t this a bug?

$ gcc bug.c
bug2.c: In function main': bug2.c:15: error: request for membera’ in something not a structure or union

Submitted on 27 April 2007 at 05:52

STR-721, martin:
Yes, this is a bug, but I don’t think we will fix this. The C grammar that is part of Stratego/XT is rather poor and it is not intended to be used to implement real C transformations. It’s main purpose is pretty-printing the generated code of the Stratego compiler. For this reason we have removed the tools parse-c and pp-c from the latest unstable distributions (the tool parse-c gave many people the impression that this tool can actually be used to parse C ;) ).

If you want to do something with C, then I advice to use the C grammar and tools of the C-Transformers project, or the C grammar of the SDF Library (but that one does not come with a pretty-printer).