Patching SQLite

The patches for SQLite are applied against the plain source, not the amalgamated source.

SQLite comes in two forms. First, there's the "plain" form. It looks a lot like a typical open-source C project: there's a bunch of .c and .h files, a Makefile, a configure script, and various other files. workerd consumes this form.

Second, there's the "amalgamation". This is all of SQLite combined into two .c and two .h files. https://www.sqlite.org/download.html puts the amalgamation front and center, but don't be fooled.

To update to a new SQLite version, obtain the new SQLite in plain form. Apply the patches to SQLite, fixing as necessary, and replace any patches that needed modification with their fixed versions.

Example, assuming the new SQLite has been downloaded into the current directory:

export VERSION=3470000
unzip sqlite-src-$VERSION.zip
mv sqlite-src-$VERSION sqlite-src-pristine
unzip sqlite-src-$VERSION.zip  # yes, again
mv sqlite-src-$VERSION sqlite-src-modified

Now patch:

cd sqlite-src-modified
patch -p1 < /path/to/workerd/patches/sqlite/0001-row-counts-plain.patch
./configure && make test

Make sure the tests pass. If the patch needed any modification, regenerate it:

diff -u5 -r sqlite-src-pristine sqlite-src-modified \
    | grep -v "Only in sqlite-src-modified" \
    > /path/to/workerd/patches/sqlite/0001-row-counts-plain.patch

Repeat for each patch.