tree 334c5a22c18321c5e4fb6e6cda31dae76d72d5ad
parent 5787e994aa4cb6cdb09c2c72ae6f1c6a7f1cf91a
author David 'Digit' Turner <digit@google.com> 1708455335 +0100
committer GN LUCI <gn-scoped@luci-project-accounts.iam.gserviceaccount.com> 1709038346 +0000

Implement new --ninja-outputs-file option.

The CL adds a new option to the `gen` command to
write a file listing all Ninja output paths that
appear in the generated build plan for any GN target
in the graph.

This can be used by GN clients to quickly convert between
GN labels and Ninja target paths. In particular, the Fuchsia
team will use this to improve developer workflows, by allowing
the `fx build` command to support GN labels directly.

The generated output includes all Ninja paths, including stamp
files for completeness. It can be processed by an external
tool, for example to convert it into a more efficient binary
format.

On a large Fuchsia build plan, this adds about 400ms
of generation time, on top of a total of 13s. Which is
drastically faster than generating a project.json file
(which is also significantly larger, and doesn't contain
all Ninja outputs).

Change-Id: I78318809f4000416689857ec4c676975ddb18061
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/16000
Reviewed-by: Takuto Ikuta <tikuta@google.com>
Commit-Queue: David Turner <digit@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>