CreateAliasVariation creates a new variation for the current mutator
that is an alias to a variation that was created with CreateVarations
by the same mutator.  It is similar to AliasVariation, except that
AliasVariation creates an alias from the pre-mutated variant to one
of the new variations, while CreateAliasVariation creates an alias
from a new post-mutated variation to one of the new variations.

Bug: 164216768
Test: TestCreateAliasVariation
Change-Id: I8847b8d6fc1d3248abc910b2fe2399881f9bdaee

Combine variant, variations and dependencyVariations into a single
struct.

Test: blueprint tests
Change-Id: I76811bb2bdf76f1b4cffc6a7b9bc7362ecb5f7b9

Adds support for making the replacement of one dependency with another
conditional on the from and to module as well as the tag used.

Change-Id: I66e85ba2e5eaea05fe976b7065985ff662d2dfec

This allows guarding calls to AddVariationDependencies and
AddReverseDependency to register dependencies on optional modules.

Change-Id: Ie43b8606f226b098daf00c4276412a98617d3f15

Change-Id: I8875f3f7686f9be5687d2d0f875f468df334f5df

Change-Id: Icc3d03d869d972959045fd4aac858aeafc4eb3b3

* goog/mirror-aosp-master:
  Support checking syntax of generated Blueprint files
  Always emit rules for tests and add phony to run them

Bug: 155628860
Test: treehugger
Change-Id: Ie843b929edf1c11c201792eefcb7772b1e6daeb8

* aosp/upstream:
  Support checking syntax of generated Blueprint files
  Always emit rules for tests and add phony to run them

Bug: 155628860
Bug: 156428456
Test: treehugger
Change-Id: Ia0e0c8d8d07489c945d4e03d039273cc3f597ac0

Support checking syntax of generated Blueprint files

Adds a CheckBlueprintSyntax(...) method to check the syntax of a
Blueprint file.

Changes processModuleDef and newModule from being method on *Context to
being standalone functions. That ensures that CheckBlueprintSyntax(...)
does not need to take a context and so there is no chance that it can
change its state.

Always emit rules for tests and add phony to run them

Emit the rules to build blueprint tests even if runGoTests is not
set, and add a phony rule "blueprint_tests" to run them.  This will
allow Soong to stop running the tests at the beginning of every build
but still run them as part of checkbuild or with a manual
`m blueprint_tests`.

Bug: 156428456
Test: m
Test: m blueprint_tests
Change-Id: If293a0757766d3046e78bf230a1825f15adc68fd

Change-Id: Iba3ab9552a1f478a068154f07f817f01dee5d3ac

Change-Id: Iff1292b0504285196328fe2bd3c21dca03bfc35c

* goog/mirror-aosp-master:
  Run LoadHooks before registering module
  Actually write an empty ninja file with --empty-ninja-file

Bug: 155462403
Test: treehugger
Change-Id: Ia2e5856c52407cebca56abb195915b370e26f0e7
Merged-In: I649f2a524f200d696b038ee6bc99d95308e1b475

* aosp/upstream:
  Run LoadHooks before registering module

Bug: 155462403
Test: treehugger
Change-Id: I649f2a524f200d696b038ee6bc99d95308e1b475

Run LoadHooks before registering module

Previously a LoadHook could not modify the name of a module because the
module was registered before the LoadHooks were run. That made it very
complicated (requiring mutators and auto generated names) to create a
module type whose name was determined by say the directory in which it
is defined.

This change moves the LoadHook execution slightly earlier so it runs
before registration of the module.

That caused one slight side problem which was that the
moduleInfo.Name() would fail when called in a LoadHook. That was
because that gets the name from group.name but was group was nil
because it is only set when the module is registered.

Modifying the moduleInfo.Name() method to get the name from the module
logicModule.Name() if group is nil fixed that. The reason for getting
the name from the group.name rather than the logicModule.Name() is that
the former tracks renames but the latter does not. However that is not
an issue in this case as there has been no opportunity for the module
to be renamed until after the LoadHook has returned.

* aosp/upstream:
  Actually write an empty ninja file with --empty-ninja-file

Test: treehugger (build_test)
Change-Id: Iff7851f2aa39eb14b7ae72ed6ce94fa0ce8d2621

Actually write an empty ninja file with --empty-ninja-file

Otherwise we'll re-run the primary builder every time this is used. This
triggered my new ninja checks that verify that all commands write their
outputs.

Change-Id: Ic92d1ea57203b953da8025a170b24e6420c5436c

Change-Id: I65c62855a02dc27046ecae22b537d6fe55061918

Change-Id: Ica8e69291ed3d03cb60079ba570776e7ffb6ed63

Update rvc-dev build/blueprint to match current AOSP master.

* goog/mirror-aosp-master:
  WalkDeps - only record module visited when it has been recursed into
  Allow missing variants when allowMissingDependencies=true
  bpmodify: fix os.Exit() shouldn't shadow panic()
  bpmodify: respect exitCode
  Set bpmodify usage function
  Fix bug in buildPropertyMap in previous commit.
  Fix missing dependencies from mutators
  Implement list of maps
  In kzip files, compilation unit paths should be relative to top.

Fixes: 150689149
Test: m checkbuild
Change-Id: I38d4b4f5fd51f9467019b7ed8cdeaec1e0798ae3

* aosp/upstream:
  WalkDeps - only record module visited when it has been recursed into
  Allow missing variants when allowMissingDependencies=true
  bpmodify: fix os.Exit() shouldn't shadow panic()
  bpmodify: respect exitCode
  Set bpmodify usage function

Test: treehugger
Change-Id: Ida99d7412ea3c034e1ddce228b1e851c1dc40cc2

WalkDeps - only record module visited when it has been recursed into

Previously, WalkDeps() would record that a module was visited after the
first time it encountered the module irrespective of whether it recursed
into or not. This change moves the recording so it happens only after it
has been recursed into.

Added TestWalkDepsDuplicates_IgnoreFirstPath to test the change. Without
the change the test fails because it does not visit E.

Test refactoring:
* A depsMutator was added instead of relying on blueprintDepsMutator to
  allow different tags to be used for different dependency types.
* Modified barModule and fooModule to support the new depsMutator and
  add support for another type of dependency that is ignored by the
  walking code.
* Extracted walkDependencyGraph() function to reuse common code.

Allow missing variants when allowMissingDependencies=true

bpmodify: fix os.Exit() shouldn't shadow panic()

The `defer func() { os.Exit() }()` in main() method shadows panic().
Make the exit handler recover() from panic(), log the panic(), and then
gracefully exit.

Test: m bpmodify
Change-Id: Icc89f8fce0b6096489baa0ba0f08c21d1ef623bc

bpmodify: respect exitCode

Set bpmodify usage function

main() method calls os.Exit(exitCode) upon return, respecting any
exitCode set by the report() method.

Test: bpmodify -w; echo "$?"
Test: bpmodify Android.bp; echo "$?"
Test: # echo command should output "2"
Change-Id: Iaf056301eaba3f249b256ecf0f0d87f8a4df1c58

* changes:
  Merge remote-tracking branch 'upstream/master' into upstream_merge
  Merge remote-tracking branch 'upstream/master' into upstream_merge

* upstream/master:
  Fix bug in buildPropertyMap in previous commit.
  Fix missing dependencies from mutators

Test: 'm nothing' runs internal tests
Change-Id: Id1b9ae002e62351a8ec0d27c249ca25ef949ff5f

Fix the bug in buildPropertyMap in the previous commit.

golang `flag` package's default FlagSet `flag.CommandLine` calls
`flag.Usage` and `os.Exit(2)` on error to print the usage string.
Set `flag.Usage` to our custom usage function.

Test: m bpmodify; bpmodify -h; bpmodify --help
Change-Id: Ida107b0dbb07c291c3d7ea90eda9147d04a7cd51

Property value should be evaluated before proeprty map is populated with
it. Added the test for this case.

Fix missing dependencies from mutators