llvm-objcopy produces 160MB binary. It used to be 74KB

[dc740]

I'm developing a platform for TockOS. They upgraded the nightly version from 03-06 to 06-03, and now llvm-objcopy produces a 160MB binary instead of a 74KB binary. I also tried on the latest nightly (06-09), and the result is the same.

I tried this code with the same .elf file:

~/.rustup/toolchains/nightly-2020-06-03-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-objcopy --output-target=binary ./edu-ciaa.elf ./edu-ciaa.06-03.bin

~/.rustup/toolchains/nightly-2020-03-06-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-objcopy --output-target=binary ./edu-ciaa.elf ./edu-ciaa.03-06.bin

I expected to see both binaries have roughly the same size, since both are applied to the same elf file. (which can be found here: https://github.com/dc740/tock/blob/fd6517da9f22d088a30d6b7cb767e42ab820814f/boards/ciaa/edu-ciaa/sample-edu-ciaa.elf )

Instead, the produced binary from nightly 03-06 is 74KB and the one produced by the newer nightly versions 06-03 and 06-19 is 160MB.

Meta

rustc --version --verbose:

rustc 1.46.0-nightly (feb3536eb 2020-06-09)
binary: rustc
commit-hash: feb3536eba10c2e4585d066629598f03d5ddc7c6
commit-date: 2020-06-09
host: x86_64-unknown-linux-gnu
release: 1.46.0-nightly
LLVM version: 10.0

[wesleywiser]

@rustbot ping llvm

Does anyone know what's going on here?

[rustbot]

Hey LLVM ICE-breakers! This bug has been identified as a good
"LLVM ICE-breaking candidate". In case it's useful, here are some
instructions for tackling these sorts of bugs. Maybe take a look?
Thanks! <3

cc @camelid @comex @cuviper @DutchGhost @dyncat @hanna-kruppe @hdhoang @heyrutvik @JOE1994 @jryans @mmilenko @nagisa @nikic @Noah-Kennedy @SiavoshZarrasvand @spastorino @vertexclique

[nagisa]

It appears that the LLVM version shipped with rustc is used. There has been a bump in LLVM version in the time range, which is most suspect here.

[spastorino]

@rustbot ping cleanup

It would be nice to find where this has regressed, as @nagisa noted, likely to be in an LLVM bump.

[rustbot]

Hey Cleanup Crew ICE-breakers! This bug has been identified as a good
"Cleanup ICE-breaking candidate". In case it's useful, here are some
instructions for tackling these sorts of bugs. Maybe take a look?
Thanks! <3

cc @AminArria @camelid @chrissimpkins @contrun @DutchGhost @elshize @ethanboxx @h-michael @HallerPatrick @hdhoang @hellow554 @imtsuki @kanru @KarlK90 @LeSeulArtichaut @MAdrianMattocks @matheus-consoli @mental32 @nmccarty @Noah-Kennedy @pard68 @PeytonT @pierreN @Redblueflame @RobbieClarken @RobertoSnap @robjtede @SarthakSingh31 @senden9 @shekohex @sinato @spastorino @turboladen @woshilapin @yerke