Fix genantlr() to support buck caching
genrule() can only produce one output. This is critical to the way
buck caching works for build results. The solution I learned from
the Buck team is to have the genrule() produce a ZIP file containing
all of the outputs, and use a unique genrule() to extract each
output from the ZIP.
Developers can now opt-into the buck cache by writing a local
config file:
cat >.buckconfig.local <<EOF
[cache]
mode = dir
dir = buck-cache
EOF
This can be very useful when switching commits around with GWT UI
code. If the UI code does not modify between commits there is no
rebuild time. If UI code does modify, rebuild time is reduced to
0 when switching back to a prior version you had previously built.
The cache needs local disk, so its not enabled by default.
Change-Id: If8f79637004fbc13ea37c419e5c9bb582a489ab5
5 files changed
