plugin specific LTO data?

[Richard Guenther]

On Wed, Oct 28, 2009 at 6:34 PM, Basile STARYNKEVITCH
<basile@starynkevitch.net> wrote:
> Hello All,
>
> Is there some way from a plugin to read and to write some plugin specific
> LTO data?
>
> When glancing in lto-streamer.h I believe I see no such things. But I don't
> understand all the details.
>
> I was thinking of e.g. functions like
>
> void lto_input_plugin_data(struct lto_file_decl_data*file_data,
>                           const char* plugin_name,
>                           char **datap,
>                           size_t*sizep);
>
> A pass from the plugin FOO would call
>
>   char* mydata = NULL;
>   size_t mydatasize = 0;
>   lto_input_plugin_data(file_data, "FOO", &mydata, &mydatasize);
>
> and then the buffer mydata would be malloc-ed by the LTO infrastructure and
> it will be read, and mydatasize set to the size of the read data.
>
> For writing, I would be happy with
>
> void lto_output_plugin_data(struct lto_file_decl_data *file_data,
>                            const char* plugin_name,
>                            char* data, size_t size);
>
> and the plugin would call
>   lto_output_plugin_data(file_data, "FOO", mydata, mysize);
>
> Perhaps the lto_file_decl_data* type above is wrong (and should be something
> else).
>
> Is it too late to add such a simple functionality in the LTO infrastructure.

You have to write an IPA pass, those can output/input pass specific data
to the LTO sections.  No need to add anything plugin specific.

Richard.