The Android fork of Ninja supports "validations", a node that is
added to the top level of the build graph whenever another node
is in the build graph. Add support in Blueprint to specify them
on build statements and write them to the ninja.
Test: ninja_writer_test.go
Change-Id: I87cd1281dbd2ed113cc26a265c50d20c65118c91
Blueprint is a meta-build system that reads in Blueprints files that describe
modules that need to be built, and produces a
Ninja manifest describing the commands that
need to be run and their dependencies. Where most build systems use built-in
rules or a domain-specific language to describe the logic for converting module
descriptions to build rules, Blueprint delegates this to per-project build
logic written in Go. For large, heterogenous projects this allows the inherent
complexity of the build logic to be maintained in a high-level language, while
still allowing simple changes to individual modules by modifying easy to
understand Blueprints files.
9ece72b055
