If a field is initialized with null (either explicitly or implicitly),
field store can be omitted in bytecode. In such case, bytecode should
still convey the information about this initialization to VM for
field guards to work correctly.
Change-Id: I1fd45b858c3c521b97fa5dbffe0e15b1ea75d92f
Reviewed-on: https://dart-review.googlesource.com/76060
Reviewed-by: Zach Anderson <zra@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Metadata is no longer written ahead of all nodes. Instead, metadata for
each node is written in the same context as the node itself (into a separate
buffer). This allows metadata to contain (serialize) arbitrary nodes
(for example, arbitrary DartTypes) and use serialization context of parent
nodes (such as declared type parameters).
However, with this change metadata looses the ability to reference
arbitrary AST nodes. This ability was overly restricted and had no
practical uses. (It was not possible to reference nodes which are not
reachable from root Component. As a consequence, it was not possible to
write references to arbitrary DartTypes.)
This change aligns the serialization capabilities of metadata with
how kernel AST nodes are serialized.
Change-Id: I027299a33b599b62572eccd4aa7083ad1dd2b3b3
Reviewed-on: https://dart-review.googlesource.com/54481
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
To enable bytecode generation, toggle kEnableKernelBytecode flag at
the beginning of pkg/vm/lib/bytecode/gen_bytecode.dart.
This will also enable generation of bytecode in platform dill files.
Also, bytecode generation can be enabled using --gen-bytecode option of
pkg/vm/tool/gen_kernel.
In kernel binaries, the generated bytecode and constant pool are
placed into 'vm.bytecode' metadata attached to members.
pkg/vm/tool/dump_kernel tool can be used to disassemble
bytecode and print constant pool.
Differences between generated bytecode and original DBC are
described in pkg/vm/lib/bytecode/dbc.dart.
Format of constant pool is described in
pkg/vm/lib/bytecode/constant_pool.dart.
Currently, only a small subset of Dart language is supported.
Bytecode generator will not emit vm.bytecode metadata for a
member if its body has an unsupported operation.
Change-Id: I27d9a361dc779ea115e5676508ee757c1754e05d
Reviewed-on: https://dart-review.googlesource.com/49600
Reviewed-by: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Zach Anderson <zra@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Alexander Markov