[Tinycc-devel] severe regression in TCC compiling and linking kernel since may 2022

[Michael Ackermann]

Good evening.

For several month i was trying to salvage tccboot JiT and AoT compilation of
linux-2.4 kernel. This covered a notable amount of test-cases, and didn't yield
a stable known-good baseline with any, to emit a bootable kernel.
Recently i could identify a somewhat severe regression in tcc introduced
may 2022, commit-id 8e860702e44ca1279098e0fc2142ad579774b1d2

Reverting this commit shows linux-2.4.37.11 can be compiled,linked and booted
without problems. Too rebasing this backout/revert up until october 2024
(commit c21576f8a32715ab439690d18184b0e02022bbbd) was possible and linux-2.4
compiled/linked with tcc then booted flawlessly again.

Linux-2.4 kernel compilation seems a reasonable test-case, hence it was
introduced by Fabrice 20 years ago with tccboot too. And the regression that
broke compilation/linking of kernel went unnoticed for more than 2 years on mob
branch.

Instead of reverting/backing-out the mentioned change on mob branch maybe it's
possible to address the issue by fixing the regression.

The revert/backout diff that i could confirm that tcc succeeds compiling/linking
kernel with is attached.

--

07-revert-8e860702-c21576f8-kernel_compile.diff
Description: Text document

8e860702e44ca1279098e0fc2142ad579774b1d2-revert.diff
Description: Text document

signature.asc
Description: Digital signature