Question about creating global varaiable during IPA PASS.

[Hanke Zhang <hkzhang455@gmail.com>]

Hi, I'm trying to create a global variable in my own PASS which
located at the LATE_IPA_PASSES. (I'm using GCC 10.3.0.)

And after creating it, I added the attributes like the following.

// 1. create the var
tree new_name = get_identifier (xx);
tree new_type = build_pointer_type (xx);
tree new_var = build_decl (UNKNOWN_LOCATION, VAR_DECL, new_name, new_type);
add_attributes (new_var);

static void
add_attributes (tree var)
{
DECL_ARTIFICIAL (var) = 1;
DECL_EXTERNAL (var) = 0;
TREE_STATIC (var) = 1;
TREE_PUBLIC (var) = 1;
TREE_USED (var) = 1;
DECL_CONTEXT (var) = NULL_TREE;
TREE_THIS_VOLATILE (var) = 0;
TREE_ADDRESSABLE (var) = 0;
TREE_READONLY (var) = 0;
if (is_global_var (var))
  set_decl_tls_model (var, TLS_MODEL_NONE);
}

But when I try to compile some example files with -flto, error occurs.

/usr/bin/ld: xxx.ltrans0.ltrans.o: in function `xxx':
xxx.c: undefined reference to `glob_var'
xxx.c: undefined reference to `glob_var'
xxx.c: undefined reference to `glob_var'

Here `glob_var' is the global varaiable created in my PASS.

I would like to ask, am I using some attributes incorrectly?

Thanks
Hanke Zhang