Should kernel_abi.h use <linux/types.h>

[GitMensch]

... and then __kernel_dev_t, __kernel_ino_t, __kernel_mode_t, __kernel_gid_t t, __kernel_pid_t instead of the own typedef?

[rocallahan]

Where exactly do you want to use these types?

We need our own typedefs in kernel_abi.h because for 32 vs 64-bit the definitions are different. And at some point it might be useful to have access to the Aarch64 types on x86 and vice versa.

[GitMensch]

I've thought the __kernel ones were exactly for using the widest types independent of architecture.

If that's not the case then the existing ones seem to need be needed out of the struct and use an rr_prefix - then be used within the header (which may be reasonable in any case, no matter which types we use) to fix

In file included from /__w/rr/rr/src/Registers.h:15,
                 from /__w/rr/rr/src/Event.h:13,
                 from ...
/__w/rr/rr/src/kernel_abi.h:2514:5: error: 'dev_t' does not name a type; did you mean 'div_t'?
 2514 |     dev_t st_dev;
      |     ^~~~~
      |     div_t
/__w/rr/rr/src/kernel_abi.h:2515:5: error: 'ino_t' does not name a type; did you mean 'wint_t'?
 2515 |     ino_t st_ino;
      |     ^~~~~
      |     wint_t
/__w/rr/rr/src/kernel_abi.h:2516:5: error: 'mode_t' does not name a type
 2516 |     mode_t st_mode;
      |     ^~~~~~
/__w/rr/rr/src/kernel_abi.h:2517:5: error: 'nlink_t' does not name a type
 2517 |     nlink_t st_nlink;
      |     ^~~~~~~
/__w/rr/rr/src/kernel_abi.h:2520:5: error: 'dev_t' does not name a type; did you mean 'div_t'?
 2520 |     dev_t st_rdev;
      |     ^~~~~
      |     div_t
/__w/rr/rr/src/kernel_abi.h:2523:5: error: 'blksize_t' does not name a type; did you mean 'ssize_t'?
 2523 |     blksize_t st_blksize;
      |     ^~~~~~~~~
      |     ssize_t
/__w/rr/rr/src/kernel_abi.h:2525:5: error: 'blkcnt_t' does not name a type
 2525 |     blkcnt_t st_blocks;
      |     ^~~~~~~~
/__w/rr/rr/src/Event.h:220:3: error: 'dev_t' does not name a type; did you mean 'div_t'?
  220 |   dev_t device;
      |   ^~~~~
      |   div_t
/__w/rr/rr/src/Event.h:221:3: error: 'ino_t' does not name a type; did you mean 'wint_t'?
  221 |   ino_t inode;
      |   ^~~~~
      |   wint_t

[rocallahan]

I don't know why you're getting those errors. GenericArch should have inherited a definition of dev_t from KernelConstants.

Is dev_t a #define in musl?

[GitMensch]

It seems to be a normal typedef: https://git.musl-libc.org/cgit/musl/tree/include/alltypes.h.in#n31

[rocallahan]

Ah I figured it out.

The errors in Event.h are simple, fixed by 9e5cb2c.

The errors in kernel_abi.h are due to weird interaction between C++ scoping rules and templates. Fixed by 60072b0.

[GitMensch]

Congrats for those type fixes, it seems I someday need to deep-dive into C++, being too exposed to C (and "recognizsing" a .h file as C header). I guess #4021 is good to go as well?