Add globbing to filesystem mocking so that more code can be tested
against the mock. Also moves the filesystem mock to pathtools,
and renames pathtools.GlobWithExcludes to pathtools.Glob, replacing
the existing pathtools.Glob.
Test: blueprint tests
Change-Id: I722df8121bc870c4a861d7c249245c57dcb607be
Add globbing with dependency checking to blueprint. Calling
ModuleContext.GlobWithDeps or SingletonContext.GlobWithDeps will return
a list of files that match the globs, while also adding efficient
dependencies to rerun the primary builder if a file that matches the
glob is added or removed.
Also use the globbing support for optional_subdirs=, subdirs= and build=
lines in blueprints files. The globbing slightly changes the behavior
of subname= lines, it no longer falls back to looking for a file called
"Blueprints". Blueprint files that need to include a subdirectory with
a different name can use build= instead of subdir= to directly include
them. The Blueprints file is updated to reset subname="Blueprints" in
case we want to include subdirectories inside blueprint and the primary
builder has changed the subname.
Also adds a new test directory that contains a simple primary builder
tree to test regeneration for globbing, and runs the tests in travis.
Change-Id: I83ce525fd11e11579cc58ba5308d01ca8eea7bc6
