On 05/29/2019 12:15 AM, Richard Biener wrote:
Of course. We are merely discussing of where the triggering of processing starts: debug hooks, or something like: dwarf2out_early_finish() { ... if (ctf) ctf_emit(); } (and then in addition if the current DWARF info would be the source of CTF info, or if it'd be whatever the compiler gives you as trees) The thing is, with debug hooks you'd have to invent a scheme of stacking hooks on top of each other (because we want to generate DWARF and CTF from the same compilation). That seems like a wasted effort when our wish is for the hooks to go away alltogether.When the debug hooks go away, the functionality can be folded in. Much like above, the ctf proposed implementation will do : ctf_early_global_decl (tree decl) { ctf_decl (decl); real_debug_hooks->early_global_decl (decl); } These ctf_* debug hooks wrappers are as lean as shown above. I do understand now that if debug hooks are destined to go away, all the implementation which wraps debug hooks (go dump hooks, vms debug hooks, and now the proposed ctf debug hooks) will need some merging. But to generate CTF, I think working on type or decl instead of DWARF dies to is a better implementation because if user wants only CTF, no DWARF trees need to be created. This way we keep DWARF and CTF generation independent of each other (as the user may want either one of these or both).The user currently can't have both DWARF and STABS either. That things like godump uses debug hooks is just (convenient?) abuse. In the end frontends will not call sth like dwarf2out_decl but maybe gen_subroutine_die () or gen_template_die (). So how do you expect the "wrapping" to work there? I understand you want CTF for "actually emitted" decls so I propose you instead hook into the symtab code which would end up calling the early_global_decl debug hook. But please don't add new debug hook users.
OK. Will I need to tap both the callsites of the early_global_decl () debug hook ? : 1. symbol_table::finalize_compilation_unit () in cgraphunit.c 2. rest_of_decl_compilation () in passes.c Or is the last one for something specific to godump debug hooks and C++ ? I guess the above will take care of the CTF generation bit. For emission, something similar should be done because DWARF hooks will not be initialized if DWARF debuginfo is not requested by the user. So I cannot have the CTF emission code in the dwarf2out*finish () debug hooks as suggested earlier. Curious to know how the current debug hook users like dbx debug hooks will be taken care of in the future design ? Is it just the wrapping/stacking of debug hooks that's problematic and not the clean instances like dbx debug hooks ?
