On 11/26/21 6:27 PM, Arnaldo Carvalho de Melo wrote:
Em Tue, Oct 19, 2021 at 11:07:23AM +0100, Douglas RAILLARD escreveu:
From: Douglas Raillard <douglas.raillard@xxxxxxx>
Allow making inner struct enums and union anonymous.
So I had to apply it by hand due to changes in the areas it touches, see
below, and I expanded a bit the commit message, please review:
Thanks for the review, it seems to be working as well as before. That said I found a couple of issues:
1. CLI options seem to abbreviate "anonymous" into "anon" so maybe we should do the same for this one ?
2. I just found a case that generates a broken header:
struct /* hrtimer */ {
struct /* timerqueue_node */ {
struct /* rb_node */ {
long unsigned int __rb_parent_color; /* 3328 8 */
struct rb_node * rb_right; /* 3336 8 */
struct rb_node * rb_left; /* 3344 8 */
}node; /* 3328 24 */
/* typedef ktime_t -> s64 -> __s64 */ long long int expires; /* 3352 8 */
}node; /* 3328 32 */
/* typedef ktime_t -> s64 -> __s64 */ long long int _softexpires; /* 3360 8 */
enum hrtimer_restart (*function)(struct hrtimer *); /* 3368 8 */
struct hrtimer_clock_base * base; /* 3376 8 */
/* typedef u8 -> __u8 */ unsigned char state; /* 3384 1 */
/* typedef u8 -> __u8 */ unsigned char is_rel; /* 3385 1 */
/* typedef u8 -> __u8 */ unsigned char is_soft; /* 3386 1 */
/* typedef u8 -> __u8 */ unsigned char is_hard; /* 3387 1 */
}hrtick_timer; /* 3328 64 */
Here we can see that "struct rb_node" is a recursive type, so since the type
definition is now anonymous it will not compile. Detecting recursive types and
printing the name would avoid that but defeats the original purpose
of --inner_anonymous.
I can see two solutions:
1. Detecting recursive types and appending a user-defined prefix to create a
unique name.
2. Detecting recursive types and replacing the recursive references by "void *".
Solution #2 is the least invasive but will require a bit more work for the
end-user of the header:
struct hrtimer foo = *ptr;
typeof(foo.node.node) node = foo.node.node;
// Extra cast using typeof in order to change the type of tb_right from void*
// to "struct rb_node*"
((typeof(node))node.rb_right)->rb_left
Thanks,
Douglas
------ 8< ------------------------
fprintf: Allow making struct/enum/union anonymous
Allow making inner struct enums and union anonymous, so that when using
-E to expand types we don't end up with multiple definitions for
expanded inner structs, allowing the resulting expanded struct to be
compilable.
Signed-off-by: Douglas Raillard <douglas.raillard@xxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
------ 8< ------------------------
⬢[acme@toolbox pahole]$ patch -p1 < ~/wb/1.patch
patching file dwarves.h
Hunk #1 succeeded at 105 (offset 6 lines).
Hunk #2 succeeded at 1372 with fuzz 2 (offset 44 lines).
patching file dwarves_emit.c
patching file dwarves_fprintf.c
Hunk #1 succeeded at 198 (offset 12 lines).
Hunk #2 succeeded at 331 (offset 12 lines).
Hunk #3 succeeded at 342 (offset 12 lines).
Hunk #4 succeeded at 395 (offset 12 lines).
Hunk #5 succeeded at 639 (offset 12 lines).
Hunk #6 succeeded at 656 (offset 12 lines).
Hunk #7 succeeded at 814 (offset 12 lines).
Hunk #8 succeeded at 824 with fuzz 1 (offset 12 lines).
Hunk #9 succeeded at 833 with fuzz 2 (offset 12 lines).
Hunk #10 succeeded at 998 (offset 23 lines).
Hunk #11 succeeded at 1013 (offset 23 lines).
Hunk #12 succeeded at 1375 (offset 23 lines).
Hunk #13 succeeded at 1396 (offset 23 lines).
Hunk #14 succeeded at 1822 (offset 23 lines).
Hunk #15 succeeded at 1909 (offset 23 lines).
Hunk #16 succeeded at 1917 (offset 23 lines).
Hunk #17 succeeded at 1929 (offset 23 lines).
⬢[acme@toolbox pahole]$
