Em Tue, Dec 07, 2021 at 05:31:45PM +0000, Douglas RAILLARD escreveu:
> From: Douglas Raillard <douglas.raillard@xxxxxxx>
>
> Improve headers generated with -E in a few ways:
>
> * Print each type only once, to avoid redefinitions
>
> * --forward_decl: Generate forward declaration for struct and union so
> that uses of pointers will work.
>
> * --expanded_prefix: Allow prefixing names of types added by -E (all
> the ones not explicitly requested with -C) so they can be namespaced
> manually. This is important in order to be able to mix
> pahole-generated headers with existing headers without clash or
> maintenance.
Looks good from a very quick first view, I'll cut 1.23 today as the BPF
guys need a release with the new BTF tag feature and then will review
this patchset.
So I've applied so far only the reverts, since yesterday I had flipped
next to master.
- Arnaldo
>
> types.txt:
>
> t1
> t4
>
> Original printed type with "-C types.txt -E":
>
> struct t1 {
> struct t2 *a;
> struct t3 {
> int a;
> } b;
> };
>
> struct t4 {
> struct t3 {
> int a;
> } a;
> };
>
> After this series and with
> "-C types.txt -E --expanded_prefix __pahole --forward_decl":
>
> struct t1
> struct t2;
> struct t3;
>
> struct t1 {
> struct t2 *a;
> struct __pahole_t3 {
> int a;
> } b;
> };
>
> struct t4 {
> struct __pahole_t3 a;
> };
>
>
> This header can be freely mixed with any other header as long as they
> don't define t1 or t4 (if there is a clash, then pahole is not necessary
> and the user can just use the header in the first place).
>
> TODOs:
>
> * Define types on their first use even when they are first used as
> pointers. Currently, if a type is only used as pointer it will never
> get defined, which will still compile thanks to --forward_decl but
> won't allow easy use of the values.
>
> * The prefix system allocates memory to rename types and never frees
> it. I don't think it's a big issue for now as it's done inside
> pahole.c and type names are likely necessary until the end of the
> process anyway, but it makes valgrind angry and could therefore mask
> other problems. There is another implementation of prefix that
> modifies dwarves_fprintf.c instead of changing the name but it was
> very invasive and impossible to check if prefixable spots were
> missed.
>
>
> This series is to be applied on the "next" branch as it includes reverts
> of the --inner_anonymous series, which is dropped since it could not
> cope with recursive types.
>
>
> Douglas Raillard (6):
> Revert "fprintf: Allow making struct/enum/union anonymous"
> Revert "pahole.c: Add --inner_anonymous option"
> fprintf: Print types only once
> pahole.c: Add prefix to expanded type names
> pahole.c: Add --expanded_prefix option
> pahole.c: Add --forward_decl option
>
> dwarves.h | 12 ++++--
> dwarves_emit.c | 2 +-
> dwarves_fprintf.c | 77 +++++++++++++++++-------------------
> man-pages/pahole.1 | 8 ++--
> pahole.c | 98 ++++++++++++++++++++++++++++++++++------------
> 5 files changed, 121 insertions(+), 76 deletions(-)
>
> --
> 2.25.1
--
- Arnaldo
