StatusPrinter: Display pending commands in smart terminals.

When NINJA_STATUS_MAX_COMMANDS is set in the environment
to a decimal value that is > 0, then display under the status
line the list of oldest running edges, with their elapsed
time.

For example, with a value of 4 in a Fuchsia checkout this looks
like the following (manual truncation to keep this readable
as a commit message):

```
ninja: Entering directory `out/default'
[5009/25019](34) STAMP fidling/obj/sdk/fidl/f...
  2.5s | CXX obj/BUILD_DIR/gen/src/lib/fostr/...
  2.2s | CXX obj/src/developer/forensics/cras...
  2.1s | CXX obj/src/lib/intl/time_zone_info/...
  2.0s | RUST obj/src/connectivity/wlan/wlanc...
```

The refresh period can be set with NINJA_STATUS_REFRESH_MILLIS
and defaults to 100 (i.e. 10 times per second).

BYPASS_INCLUSE_LANGUAGE_REASON=dumb_terminal_is_exactly_the_terminology_used_by_upstream_project
Fuchsia-Topic: multi-line-status

Original-Change-Id: I4182bad709bf4758a1b0f47006a19807bf01a7b0
Original-Change-Id: Ia6092b21f2cc35b16b1a4732ad514c5505499686
Change-Id: I90f2f1bba62d6364d5474145cdcfa4df8d1f214e
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/github.com/ninja-build/ninja/+/978778
Reviewed-by: David Fang <fangism@google.com>
Commit-Queue: David Turner <digit@google.com>
10 files changed
tree: 6122ae2f64d17ef7918f62984fb1479b06259f13
  1. .github/
  2. doc/
  3. misc/
  4. src/
  5. windows/
  6. .clang-format
  7. .clang-tidy
  8. .editorconfig
  9. .gitignore
  10. appveyor.yml
  11. CMakeLists.txt
  12. configure.py
  13. CONTRIBUTING.md
  14. COPYING
  15. README.fuchsia
  16. README.md
  17. RELEASING.md
README.md

Ninja

Ninja is a small build system with a focus on speed. https://ninja-build.org/

See the manual or doc/manual.asciidoc included in the distribution for background and more details.

Binaries for Linux, Mac and Windows are available on GitHub. Run ./ninja -h for Ninja help.

Installation is not necessary because the only required file is the resulting ninja binary. However, to enable features like Bash completion and Emacs and Vim editing modes, some files in misc/ must be copied to appropriate locations.

If you're interested in making changes to Ninja, read CONTRIBUTING.md first.

Building Ninja itself

You can either build Ninja via the custom generator script written in Python or via CMake. For more details see the wiki.

Python

./configure.py --bootstrap

This will generate the ninja binary and a build.ninja file you can now use to build Ninja with itself.

CMake

cmake -Bbuild-cmake
cmake --build build-cmake

The ninja binary will now be inside the build-cmake directory (you can choose any other name you like).

To run the unit tests:

./build-cmake/ninja_test