Implement transition mutators.

These are more limited than bottom-up or top-down mutators but in
exchange have some pleasant properties:

- "variant not found" errors are impossible
- The logic is pleasantly split into multiple, mostly orthogonal
  parts
- Theoretically, if every mutator is refactored like this, they
  make it possible to partially cache the module graph
- Are quite close to a "configuration transition" in Bazel.

Bug: 231370928
Test: Presubmits.
Change-Id: Idcdb66b5ea75c0d2838f527aaa988df3b12553d8
2 files changed
tree: 005359c0a65e6de90b540bac934597a09f05d5a9
  1. .github/
  2. bootstrap/
  3. bpfmt/
  4. bpmodify/
  5. deptools/
  6. gotestmain/
  7. gotestrunner/
  8. loadplugins/
  9. metrics/
  10. microfactory/
  11. parser/
  12. pathtools/
  13. proptools/
  14. tests/
  15. .gitignore
  16. .gofmt.sh
  17. Android.bp
  18. CODEOWNERS
  19. context.go
  20. context_test.go
  21. CONTRIBUTING.md
  22. doc.go
  23. glob.go
  24. glob_test.go
  25. go.mod
  26. LICENSE
  27. live_tracker.go
  28. mangle.go
  29. module_ctx.go
  30. module_ctx_test.go
  31. name_interface.go
  32. ninja_defs.go
  33. ninja_strings.go
  34. ninja_strings_test.go
  35. ninja_writer.go
  36. ninja_writer_test.go
  37. OWNERS
  38. package_ctx.go
  39. PREUPLOAD.cfg
  40. provider.go
  41. provider_test.go
  42. README.md
  43. scope.go
  44. singleton_ctx.go
  45. splice_modules_test.go
  46. visit_test.go
README.md

Blueprint Build System

Blueprint is being archived on 2021 May 3.

On 2021 May 3, we will be archiving the Blueprint project. This means it will not be possible to file new issues or open new pull requests for this GitHub project. As the project is being archived, patches -- including security patches -- will not be applied after May 3. The source tree will remain available, but changes to Blueprint in AOSP will not be merged here and Blueprint's source tree in AOSP will eventually stop being usable outside of Android.

Whereas there are no meta-build systems one can use as a drop-in replacement for Blueprint, there are a number of build systems that can be used:

  • Bazel, Google's multi-language build tool to build and test software of any size, quickly and reliably
  • Soong, for building the Android operating system itself
  • CMake, an open-source, cross-platform family of tools designed to build, test and package software
  • Buck, a fast build system that encourages the creation of small, reusable modules over a variety of platforms and languages
  • The venerable GNU Make