This change supports compilation of components, directives, and modules
within ngtsc. Support is not complete, but is enough to compile and test
//packages/core/test/bundling/todo in full AOT mode. Code size benefits
are not yet achieved as //packages/core itself does not get compiled, and
some decorators (e.g. @Input) are not stripped, leading to unwanted code
being retained by the tree-shaker. This will be improved in future commits.
PR Close#24427
Previously, the transitive scopes of an NgModuleDef were computed
during execution of the @NgModule decorator. This meant that JIT-
compiled modules could only import other JIT-compiled modules, as
the import mechanism relied on the calculation of transitive scopes
to already have happened for the imported module.
This change moves computation of transitive scopes to a function
`transitiveScopesFor` (and makes it lazy). This opens the door for
AOT -> JIT or JIT -> AOT imports, as transitive scopes for AOT
modules can be calculated when needed by JIT, and AOT modules can
also write expressions that call `transitiveScopesFor` when
importing a JIT-compiled module.
PR Close#24334
This commit adds a mechanism by which the @angular/core annotations
for @Component, @Injectable, and @NgModule become decorators which,
when executed at runtime, trigger just-in-time compilation of their
associated types. The activation of these decorators is configured
by the ivy_switch mechanism, ensuring that the Ivy JIT engine does
not get included in Angular bundles unless specifically requested.
PR Close#23833