Create multiarch image by cross-compiling Swift package to `arm64` #125

fwcd · 2022-12-29T18:49:52Z

Fixes #124

Enable linux/arm64/v8 platform in Ci workflow again
Make the build scripts aware of their target architecture
Bootstrap an arm64 sysroot
Provide the correct Swift flags for cross-compilation

Implementation notes:

The new Swift cross-compilation SDKs might make this much easier:
- https://github.com/apple/swift-evolution/blob/main/proposals/0387-cross-compilation-destinations.md
SPM's destination.json mechanism might be interesting:
- https://github.com/apple/swift-package-manager/blob/14d05ccaa13b768449cd405fff81d630a520e04a/Utilities/build_ubuntu_cross_compilation_toolchain#L248-L266
This thread might be interesting too:
- https://forums.swift.org/t/swift-build-passing-l-usr-local-lib-when-cross-compiling/59304
Perhaps we could reuse/combine some existing work on cross-compilation toolchains to produce an x86_64 Linux -> arm64 Linux toolchain:
- macOS -> arm64 Linux: https://github.com/CSCIX65G/SwiftCrossCompilers
- arm64 Linux -> macOS: https://github.com/helje5/swift-arm2mac-x-compile-toolchain

Future directions:

Investigate which packages/flags/workarounds could be dropped without breaking the cross-build (e.g. build-essential in install-build-dependencies-apt)
Strip down the sysroot copied into the builder, see Dockerfile

...for cross-compilation.

...in order to not interfere with cross-GCC packages.

This seems to work better with the Swift cross-linker (lld), since we now have a -tools-directory we can point it at.

...to make sure D2 finds the Swift standard libraries at runtime.

The layers are probably too large for this

fwcd added enhancement New feature or request ci-cd CI/CD-related (GitHub Actions, GitLab CI, ...) docker Docker-related labels Dec 29, 2022

fwcd force-pushed the docker/cross-compile-image branch from cd904f7 to 728904e Compare December 29, 2022 18:52

fwcd added 26 commits January 1, 2023 23:51

Run Docker workflow on all 'docker/'-prefixed branches

08d4155

Use 2-space indent in scripts

956005d

Extract arch-aware build scripts from Dockerfile

0011fc5

Build arm64 image in CI again

96c18d1

Force scripts to run in bash

c4eac68

Pass TARGETOS and TARGETARCH from Dockerfile

7d73cea

Declare TARGETOS and TARGETARCH as ARGs

3b6f508

Make sure .build is always created

105873a

Set up include and linker paths for crosscompiling

9329e12

Use single-line if for installing crossbuild sysroot

7460baf

Move cross-compilation setup into dependencies script

1a68836

Install the native target toolchain to get the Swift libraries

006e1f0

...for cross-compilation.

Fix ARG syntax

56f4e6b

Renew ARG for second stage

ed4807c

Add unified script for setting up cross sysroot with qemu-debootstrap

388ad62

Fix typo

83b946c

Set up schroot configuration

08a770a

Chroot directly into sysroot

85f1ff9

Output the new sysroot for debugging

4b6703a

Script chroot properly

40e3664

Remove unused DEBIAN=ON flag

8483e74

Enable repositories in install-build-dependencies-apt

c7d881e

Install add-apt-repository before using it

2089be7

Fix sysroot path

e82b04c

Set cross compile sysroot paths manually again

9a11317

Add build-essential to APT dependencies

2caeeeb

fwcd force-pushed the docker/cross-compile-image branch from d333b70 to e588b87 Compare July 30, 2023 15:49

fwcd and others added 26 commits July 30, 2023 17:57

Copy get-linux-arch-name in earlier step already

d021efb

Set workdir earlier

92bf511

Use multi-stage build to create sysroot

be190dd

Remove legacy cross-compile sysroot scripts

974cd92

Add $arch_name-linux-gnu to linker path

8c07d20

Work around glibc header issue

7e0dcf2

Work around <tgmath.h> issue

abdafad

Install libstdc++-12-dev as build dependency

684ba14

Use lld as linker

6a15b90

Include standard headers from target sysroot

51e6b57

Place target sysroot under /usr/local

3cd4021

...in order to not interfere with cross-GCC packages.

Check for $TARGETSYSROOT variable

80e2a07

Install cross-GCC instead of installing it natively to the sysroot

8863b3a

This seems to work better with the Swift cross-linker (lld), since we now have a -tools-directory we can point it at.

Install native GCC if not cross-compiling

4abaabe

Symlink libc into /lib/$arch_name-linux-gnu

ebed54f

Fix typo

f0d75ed

Install native GCC into target sysroot again

f0f441d

Remove libc workaround again

fda56af

Only deploy on main

5e09f49

Reorder -tools-directory

abf64e0

Install native GCC only if not cross-compiling

36c223b

Link libstdc++ from target sysroot rather than cross-GCC

486dfe9

Symlink sysroot libs into cross-GCC libs

052c44e

Link target sysroot in runner image

5b79129

...to make sure D2 finds the Swift standard libraries at runtime.

Remove native GCC from sysroot again

8bf4abb

Disable build cache

e59ede9

The layers are probably too large for this

fwcd marked this pull request as ready for review August 2, 2023 00:12

fwcd merged commit 8efd8ac into main Aug 2, 2023
3 checks passed

fwcd deleted the docker/cross-compile-image branch August 2, 2023 00:12

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Create multiarch image by cross-compiling Swift package to `arm64` #125

Create multiarch image by cross-compiling Swift package to `arm64` #125

fwcd commented Dec 29, 2022 •

edited

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Create multiarch image by cross-compiling Swift package to arm64 #125

Create multiarch image by cross-compiling Swift package to arm64 #125

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fwcd commented Dec 29, 2022 • edited Loading

Fixes #124

Create multiarch image by cross-compiling Swift package to `arm64` #125

Create multiarch image by cross-compiling Swift package to `arm64` #125

fwcd commented Dec 29, 2022 •

edited

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