add rules to convert the current git tree/index

[MartinNowak]

convert_tree simply converts the working dir (made for tree-filter)
convert_index uses git rm and git add to prepare a conversion commit.

[MartinNowak]

# How to convert a PR against CDMD?
# update upstream and tags
git fetch upstream --tags
# checkout your branch
git checkout myBranch
BRANCH=$(git rev-parse --abbrev-ref HEAD)
# make sure your working dir is clean
git status && git clean -dn
# rebase onto last CDMD state, resolve merge conflicts as usual
git rebase --onto last-cdmd last-cdmd ${BRANCH}
# convert all commits using magicport
# In case the magicport filter-branch fails b/c you need to
# update magicport.json, redo the above rebase as interactive rebase
# and edit/update your commits as necessary.
git filter-branch -f --tree-filter '
    cp src/root/async.{h,bak}
    cp src/root/checkedint.{h,bak}
    make -C src -f posix.mak convert_tree
    mv src/root/async.{bak,h}
    mv src/root/checkedint.{bak,h}
    rm -f src/verstr.h' last-cdmd..${BRANCH}
# cleanup the working tree (still contains .c files)
git reset --hard
# rebase your new DDMD branch onto the first DDMD commit, -X theirs keeps all your changes
git rebase -s recursive -X theirs --onto first-ddmd first-ddmd ${BRANCH}
# rebase your branch onto master
git rebase --onto upstream/master first-ddmd ${BRANCH}
# update your PR
git push -f origin ${BRANCH}

last-cdmd
first-ddmd

[MartinNowak]

The LastCDMD and FirstDDMD commit are still to be determined.
I'd say we should tag them to make the above simpler.

[MartinNowak]

I didn't test the windows rules, hope they work.

[yebblies]

https://gist.github.com/yebblies/43555390d29624232ada

Yeah, so you've lost me at filter-branch. The gitignore changes do not need to be done now.

[MartinNowak]

Yeah, so you've lost me at filter-branch.

foreach (commit)
    checkout sources into tmpdir
    run command
    commit missing/updated/added files (a.k.a. just what we need)

The gitignore changes do not need to be done now.

It's rather confusing for everyone who will have to rebase their converted code onto this.

[yebblies]

It's rather confusing for everyone who will have to rebase their converted code onto this.

Just turn git add $(GENSRC) objc.d
into
git add -f $(GENSRC) objc.d

And it will work as expected, so the changes are not necessary.

This pull is missing the makefile updates from https://gist.github.com/yebblies/43555390d29624232ada

[MartinNowak]

This pull is missing the makefile updates from https://gist.github.com/yebblies/43555390d29624232ada

This should be done after the conversion.

And it will work as expected, so the changes are not necessary.

If I have to make another PR for this trivial piece I'll have to wait another hour and will rather go to bed, meaning we'll continue on monday or so.
It's not like this switch gets better by splitting it in fractal pieces.

[yebblies]

This should be done after the conversion.

Why?

[MartinNowak]

Why?

Because this is still CDMD and you want to build the C compiler.
The next PR will have the converted sources and updated makefiles.
Then we can tag the merge commit of this PR as {LASTCDMD} and the merge commit of the next PR as {FIRSTDDMD}.

[yebblies]

Auto-merge toggled on

[MartinNowak]

Damn it, you didn't delete root/{async,checkedint}.h, not this will happen in the filter-branch step, and needs to be resolved when rebasing onto upstream/master.

[MartinNowak]

I updated the tree-filter script to account for that.