Re: [PATCH] New pragma handling mechanism.

[Dmitry Kurochkin <dmitry dot kurochkin at gmail dot com>]

Hi.
I want to add a type to each pragma. This type will let front end know
what to do with pragma. At present all pragmas are handled separately
from front end so all have PRAGMA_NORMAL type. Which means that front
end should just call a handler and nothing more. OpenMP pragmas will
have different types, so the front end will be able to handle them
specially.
I have few questions.
1. What do you think of these?
2. How to tell GC to do nothing with a pointer in union?
We have:
struct pragma entry
{
  ...
  unsigned char type;
  union {
    pragma_cb handler;
    struct pragma_entry *space;
  } u;
};

struct pragma_node
{
  unsigned char type;
  pragma_cb handler;
};

struct cpp_token GTY(())
{
  ...
  union cpp_token_u
  {
    ...
    /* Pragma node. */
    struct pragma_node * GTY ((tag ("CPP_TOKEN_FLD_PRAGMA"))) pragma;
  } GTY ((desc ("cpp_token_val_index (&%1)"))) val;
};

cpp_token.val.pragma points inside the pragma_entry. pragma_entry is
not marked GTY().
How to tell GC to do nothing with cpp_token.val.pragma? Is the skip()
what I want?

-- 
  Dmitry