Anonymous struct can conflict across translation unit

[Thierry Delisle]

Given a header fred.hfa with the following code:

typedef struct { /*...*/ } my_struct_t;

void foo( my_struct_t * );

This will create a struct of name anonymous[N] where [N] is replaced by a simple counter.

Now if fred.cfa and mary.cfa include the file as follows:

--- fred.cfa ---
#include "fred.hfa"

/* ... use foo() ... */

--- mary.cfa ---
typedef struct { int i; } my_int_t;
#include "fred.hfa"

/* ... use foo() ... */

In these 2 files, since the number of structs anonymous struct differs, foo will mangle differently.

This means that it may be impossible to link the 2 files together.

Note: linux makes heavy use of typedef struct which means this can break code easily