The patch adopts and reuses the optimizations from the legacy backend.
The optimizations remove useless temporary variables,
statements and simplify generated JS code.
The optimizations can be disabled by `-Xoptimize-generated-js=false`.
Related to KT-51139
This parameter accepts the name of the "mode" in which the partial linkage would work. Currently, only two options are supported: 'enable', 'disable'. But the list may be extended in the future as needed.
At the moment the 'disable' option is the default one. This will be changed in #KT-51447, #KT-51443.
1. Leaving no unbound symbols in the IR tree, KT-54491:
- All unbound symbols are bound to synthetic stub declarations
- Improved detection of the root cause for every partially linked classifier
- Improved error messages
2. Visibility valiation, KT-54469
3. Always check deserialized symbols:
If the deserialized symbol mismatches the symbol kind at the call site in the deserializer then generate and reference another symbol with the same signature. In case PL is off, just throw IrSymbolTypeMismatchException.
4. Handle class inheritance violation:
- Detect illegal inheritance (ex: inheriting from a final class)
- Detect invalid constructor delegation (ex: delegating to another class than the direct superclass)
- Simplification: Reduce the number of PartialLinkageCase subclasses
- Reworked error message generation to have shorter and clearer messages
5. Handle class transformations and all known side-effects, examples:
- nested <-> inner
- class <-> enum/object
- adding/removing subclasses of sealed class
- adding/removing enum entries
6. Check direct instantiation of abstract class.
Such instantiation could be possible if a class was non-abstract in the previous version of a library.
7. Handle unlinked annotations on declarations.
Such annotations are removed from the IR. The appropriate compiler error message is produced for every individual case.
8. Handle value argument count mismatch at call sites
9. Handle calling suspend function from non-suspend context.
This could happen if a suspen function was non-suspend in the previous version of a library.
10. Handle overriding inline callables.
Only the leaf final callable can be marked with `inline`.
11. Detect illegal non-local returns from noinline/crossinline lambdas.
If a developer interrupts (kill gradle process) a compilation process or
an internal error interrupts the compilation process,
the incremental cache files may be corrupted.
The patch creates a special guard file, which allows detecting
if the previous compilation was not successful,
and in case of any issues drops the incremental cache files.
^KT-56581 Fixed
Optimizaion: instead of reading all non modified JS files
from the cache into the memory at once, the patch allows
copying non-modified JS files from disk one by one
during the compilation output writing routine.
Dmitriy Dolovov