Finalized the new-bootstrap script

[hartbit]

This is a fairly substantial change to the new-bootstrap script, so here's a recap of the changes:

• Split the different actions (clean, build, test, build-runtimes) into separate subparsers and implementation functions.
• Created several helpers functions to avoid code duplication, including a build_with_cmake function that calls cmake with default + custom arguments (if no CMakeCache.txt) and then calls ninja.
• Renamed a few functions to try to try to document them for future contributors (bootstrap becomes build_swiftpm_with_cmake, build_swiftpm becomes build_swiftpm_with_swiftpm).
• Re-implemented a --verbose option that outputs all shell commands executed, and modified non-verbose behaviour to be less verbose in concequence.
• Implemented the missing clean and test actions.

Let me know what you think 🙂

I replaced the code that figures out the target triple with the previous implementation from bootstrap, because clang --print-target-triple kept failing on the Linux CI. If you have any idea why, please let me know.

To help document the differences between the old bootstrap swift-build shell invocations vs new-bootstrap, and to make sure we don't overlook anything, here's a recap:

Environment variables

SWIFT_EXEC

• bootstrap: /.../.build/{target}/debug/swiftc
• new-bootstrap: args.swiftc_path

We don't symlink swiftc anymore as it isn't necessary. Instead, we pass args.swiftc_path directly.

SWIFTPM_BUILD_DIR

• bootstrap: /.../.build
• new-bootstrap: /.../.build

No change.

SWIFTPM_BOOTSTRAP

• bootstrap: 1
• new-bootstrap: 1 (only when linking to an llbuild framework)

We don't pass it anymore as want to let swift-build rebuild llbuild from scratch (when not linking to an llbuild framework).

SDKROOT

• bootstrap: /Applications/Xcode.app/.../MacOSX10.15.sdk
• new-bootstrap: nothing

We don't set this environment variable anymore, and I'm not sure if this is intended.

DYLD_LIBRARY_PATH and LD_LIBRARY_PATH

• bootstrap: nothing
• new-bootstrap: /.../.build/{target}/bootstrap/lib:/.../.build/{target}/llbuild/lib

I'm not sure why we set these environment variables in the new script if we let swift-build rebuild llbuild (see SWIFTPM_BOOTSTRAP).

Options

--disable-sandbox

• bootstrap: is set
• new-bootstrap: is not set

We don't set this option anymore and it doesn't seem to have an impact, so I think its worth leaving out.

-Xlinker -rpath -Xlinker @executable_path/../lib/swift/macosx

• bootstrap: is set
• new-bootstrap: is not set

We don't set this option anymore. Not sure if its needed or not.

-Xswiftc -Xcc -Xswiftc -DSPM_BUILD_IDENT=c3252208

• bootstrap: is set
• new-bootstrap: is not set

We don't set this option anymore. Not sure if its needed or not.

-Xswiftc -I/.../.build/{target}/debug/llbuild/products/llbuildSwift

-Xswiftc -I/.../llbuild/products/libllbuild/include

-Xlinker -rpath -Xlinker @executable_path/../lib/swift/pm/llbuild

-Xlinker -L/.../.build/{target}/debug/llbuild/lib

-Xlinker -rpath -Xlinker /.../.build/{target}/debug/llbuild/lib

• bootstrap: are set
• new-bootstrap: are not set

We don't set theses option anymore. But it seems like the would be necessary when building a CI toolchain?

[aciidgh]

Taking over for now with #2447