[Toybox] [PATCH] readelf: Fix the section flags handling.

[enh]

On Thu, Nov 30, 2023 at 9:24 PM Rob Landley <rob at landley.net> wrote:
>
> On 11/30/23 13:55, Rob Landley wrote:
> > (This is why Mike Gancarz' book "the unix philosophy" talked about unix tool
> > output being made to be easily parseable by programs rather than by humans.
> > Alas, readelf is from gnu, not from unix, which is why it sucks at this. The nm
> > tool has better unix design, which is why bloat-o-meter and make bloatcheck is
> > built on top of it. Specifically the --size-sort output which has constant
> > fields rather than this "the first word is missing half the time and the
> > indentation easily lets a human know but is a pain for a script to deal with
> > unless it wants to hardwire in column starting positions and break as soon as a
> > field width changes" of the default output.)
>
> Which I hit trying to rewrite this test, too! I was fiddling with it to make the
> test specifically test what the patch had updated, and:
>
> $ readelf -SW tests/files/elf/ndk-elf-note-shflags | sed -n 's/.*]//p' | while
> read a b c d e f g h i; do printf "$g"; done
> Flg0AAAAAAAAA04ALAIAMSAXAXWATWAWAWAWAMS0C26000
>
> Because the output:
>
>  .comment          PROGBITS        00000000 0006c8 0000cc 01  MS  0   0  1
>  .ARM.attributes   ARM_ATTRIBUTES  00000000 000794 000042 00      0   0  1
>
> Has BLANK COLUMNS. Which is BAD FOR SCRIPT PARSEABILITY. Also:
>
>  .relr.dyn         00000013: <unknown> 00000318 000318 00000c 04   A  0   0  4
>
> It inserted an EXTRA COLUMN. (This is the debian version, by the way. I'm trying
> to make TEST_HOST pass first...)
>
> Does it have any sort of stat -c syntax where I can at least REQUEST what I want
> out of it? No it does not. Because gnu. (Don't suggest it to them, they'll fsck
> it up 100% guaranteed.)

(i don't really use the gnu one any more anyway. there's an
llvm-readelf too, and -- like all the other llvm tools -- it "just
works" regardless of what architecture the ELF file is for. it's worth
switching for that alone. and they _do_ have a proper machine-readable
format if you ask for it.)

> Rob