The kernel format has been designed so that one can concatenate several
dill files into one file and then load it. For instance the dart
function BinaryBuilder.readProgram supports this.
Currently a dill file contains one or more programs.
In the VM each of these programs are called either program or subprogram.
Technically a dill "program" isn't necessarily a program at all (e.g. it
could be missing a library).
This naming snafu should probably be cleaned up at some point, but that's
for another CL.
When loading a dill file via BinaryBuilder.readProgram what happens is
this:
- Each program in the dill file ends in 4 bytes that indicates the size
of the program.
- Reading the input from the end one can then read the size, skip back
that amount of bytes, if we have more data (i.e. there's another
program), read another size and so on, and continue until we have
accounted for all bytes in the input.
- We then read each program from the start, and basically overwrite any
library, class, procedure etc. we find.
The first main reference found is the one used though.
(Saying that we overwrite is not completely true, but when the library
is a non-external library that's basically what happens).
This CL introduces (some) support on the C++ side for the same thing.
So far the C++ side could only handle single-program-dills, and trying
to load anything else would probably crash the VM.
The support added is this:
- Assume the SDK (i.e. vm_platform.dill) is not a concatenated file
(error out if it is).
- For user provided input, loop over each contained program one-by-one,
for each individual one behave as normal.
- The way LibraryLoad is implemented (i.e. it skips if the library is
already loaded) this means that it currently would behave differently
than the dart version (i.e. the first one is used, not the last one).
For now it is assumed that that's not a problem.
- There is a possibly snafu if the same script is included several times.
This could probably mostly be remedied by not creating scripts up front,
but only as needed. By the "keep only one" (and fixing the above point,
probably by simply loading in the opposite order, i.e. last program
in the binary first) the (theoretical) problem would probably do away.
Note that we will have separate string tables, canonical name tables etc
per "sub program" and that there might be some duplication.
The implementation was tested as indicated below, but introduces no tests.
$ cat test_lib1.dart
import "test_lib2.dart" as lib2;
String lib1field = "lib #1 field!!";
main() {
foo();
lib2.foo();
print("From lib2: ${lib2.lib2field}");
}
foo() {
print("Hello, Foo, from test_lib1!");
var x = 42;
print(x);
}
$ cat test_lib2.dart
String lib2field = "Lib #2 field!!!!";
foo() {
print("Hello, Foo, from test_lib2!");
var y = 34;
print(y);
}
$ out/ReleaseX64/dart pkg/front_end/tool/_fasta/compile.dart --packages=.packages --platform=out/ReleaseX64/vm_platform.dill test_lib1.dart
$ ls -lha test_lib1.dart.dill
[...] 4.2M Oct 26 14:42 test_lib1.dart.dill
$ dart pkg/kernel/bin/split.dart test_lib1.dart.dill
Wrote test_lib1.dart.dill.part1.dill
Wrote test_lib1.dart.dill.part2.dill
$ ls -lha test_lib1.dart.dill.part{1,2}.dill
[...] 811 Oct 26 14:42 test_lib1.dart.dill.part1.dill
[...] 582 Oct 26 14:42 test_lib1.dart.dill.part2.dill
$ cat test_lib1.dart.dill.part1.dill test_lib1.dart.dill.part2.dill > test_lib1.dart.dill.concat.dill
$ ls -lha test_lib1.dart.dill.concat.dill
[...] 1.4K Oct 26 14:44 test_lib1.dart.dill.concat.dill
$ out/ReleaseX64/dart --kernel-binaries=out/ReleaseX64 --packages=.packages test_lib1.dart.dill.concat.dill
Hello, Foo, from test_lib1!
42
Hello, Foo, from test_lib2!
34
From lib2: Lib #2 field!!!!
Change-Id: I233a033aa3042b202dd4708908a5be3089474588
Reviewed-on: https://dart-review.googlesource.com/16820
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Dmitry Stefantsov <dmitryas@google.com>
Devirtualization optimization now adds metadata to kernel AST instead
of transforming nodes to Direct* ones. The direct call metadata
provides information about checking receiver for null, while
Direct* kernel nodes do not support null checking.
VM's kernel binary loader is extended to extract arbitrary metadata
from kernel binaries and keep it for flow graph builder.
Kernel flow graph builder is extended to take direct call metadata
into account and generate CheckNull/StaticCall instructions
for devirtualized PropertyGet, PropertySet and MethodInvocation nodes.
Issue: https://github.com/dart-lang/sdk/issues/30480
Change-Id: I57f56fbf4a8981d33b1571c0d93105cf8ca71d76
Reviewed-on: https://dart-review.googlesource.com/12260
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
This is needed to support cases where memory with kernel binary was
allocated outside of Dart VM(for example, in Flutter Engine) has to be
released using appropriate mechanism too.
Bug:
Change-Id: I863db9e5a33469ba8fb5c1f8789c6498ddfbb385
Reviewed-on: https://dart-review.googlesource.com/5121
Commit-Queue: Alexander Aprelev <aam@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Currently serializing the ast for kernel is done in two passe:
1) Scan the program to find and index all strings. These are then
sorted based on frequency and assigned an id. All string-
references are refering to that id. As small numbers use less
space in the binary than big numbers, sorting the numbers by
frequency saves a certain amount of space.
In addition the string indexing is "hijacked" for the
"LimitedBinaryPrinter" to also perform some CanonicalName
re-indexing.
2) We then serialize the entire thing.
This CL gets rid of a pass by not indexing the strings up-front.
Whenever it is asked to serialize a string it adds it to the index
(if not already there). The serialization is otherwise the same.
This means that:
1) Strings are not sorted by frequency, i.e. the binary output size
can by bigger (numbers below).
2) The stringindex and canonical names are moved to the end of the
binary instead of the front. As we still need it up front for
deserialization some additional data is added to the
ProgramIndex.
3) The "hijacking" done in "LimitedBinaryPrinter" is replaced by
an alternative.
4) We don't spend time on walking the tree twice.
The cost is the binary size. Compiling helloworld with fasta,
as well as looking at outline.dill, platform.dill and
vmservice_io.dill reveals these numbers:
* helloworld.dill is 0.657248732% bigger (26573 bytes)
* outline.dill is 1.686911399% bigger (9395 bytes)
* platform.dill is 0.657062238% bigger (26565 bytes)
* vmservice_io.dill is 0.44991899% bigger (19147 bytes)
The cost does thus not appear to be very big.
The gain is the serialization time.
From 20 runs of an instrumented VM/serialization, running numbers
through calculations stolens from ministat
(https://www.freebsd.org/cgi/man.cgi?query=ministat) reveals the
following:
* Serialization time: -21.69% +/- 1.44%
* Total time spend in relevant parts of bootstrap_nocore.cc,
dart_api_impl.cc (Dart_LoadKernel), bootstrap_nocore.cc,
dart_api_impl.cc (LoadKernelProgram) as well as serialization:
-14.01% +/- 1.58%
From 5 runs of
"time python tools/test.py -m release -cdartk language -j6"
(again run through ministat calculations):
* real: -4.18% +/- 0.5%
* user: -4.2% +/- 0.29%
* sys: No difference at 95%
* user+sys: -3.3% +/- 0.36%
Change-Id: I1c220eac083496994f0a9f1e2a2445b3707c9a93
Reviewed-on: https://dart-review.googlesource.com/2880
Reviewed-by: Samir Jindel <sjindel@google.com>
There already exists a class named "Reader" in the "kernel" namespace
which reads bytes from a kernel binary. The class KernelLoader
(KernelReader before this change) creates VM heap objects and populates
them.
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/3010543002 .
The Kernel C++ implementation no longer has classes like Library,
Class, Field, or String, so it's no longer necessary to explicitly
write `dart::` in most places.
BUG=
R=jensj@google.com
Review-Url: https://codereview.chromium.org/3001103002 .
This should cleanup user script kernel data and service isolate kernel data,
but leave the platform kernel data alone as it is used several times,
and it is unclear to me when it is safe to free it.
BUG=
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/3000623002 .
Mostly stream kernel_reader, i.e. the code that sets up the libraries,
classes, methods etc.
Mostly because it still takes a "Program" ast node, and looks at the
"Library" ast nodes to get their kernel offset in the binary.
Currently the scripts (containing breakable points etc) are also created
from the ast nodes.
The rest is now streamed.
This also means that more ast visitors could be deleted.
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/2931813002 .
- Put pointer to kernel data into Script.
- Replace function.kernel_function pointer to AstNode with
kernel_offset():
- Replace field.kernel_field pointer to AstNode with kernel_offest().
- Stream the previously unstreamed AstNodes: FunctionDeclaration and
FunctionExpression.
- Move special handling for _buildin.getMainClosure into the streaming
flowgraph builder.
- Delete big parts of kernel_to_il.
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/2901533002 .
This CL allows for streaming big parts of the binary,
i.e. without using the AST nodes.
It is thus a stepping-stone in getting rid of the AST nodes in the VM.
Generally, all Expressions except "FunctionExpression",
and all Statements except "FunctionDeclaration" can be streamed.
There are currently not streamed because they create new functions,
which has a pointer to an AstNode (which we don't have when streaming).
Once we no longer need AstNodes at all these can be streamed as well.
This is, I think, mostly a matter of streaming the ScopeBuilder as well,
something that is not currently done.
The way the streaming is build, one has to stream an entire subtree.
That means, that if an expression (or statement), A, that is generally
streamable contains an expression or a statement, B, that is not streamable,
A cannot be streamed.
The way this is build is by marking AstNodes as streamable or not
("cannot_stream_" field). That way we know up front whether we can stream
a subtree or not.
The streaming is done via "kernel_binary_flowgraph".
In this file there are many obvious comments, e.g.
```
TokenPosition position = ReadPosition(); // read position.
```
This has been done in an attempt to add a comment to everything that
reads from the binary to make it stand out more.
All changes from kernel_to_il up to and including May 2nd 2017
should be included.
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/2854393002 .
In the VM's Kernel representation, introduce wrapper classes for
string and name indexes so it is obvious which one is which. For
convenience there is an implicit conversion so that they can each be
used where an int is allowed. However, there is no implicit
conversion _to_ either of these types.
BUG=
R=vegorov@google.com
Review-Url: https://codereview.chromium.org/2860823002 .
The canonical name table is copied into a typed data array in the VM's
heap. The encoding is the same as in the binary except that the
integer indexes are fixed-size.
Canonical names are now integer indexes instead of objects allocated
in the C++ heap.
BUG=
R=jensj@google.com, vegorov@google.com
Review-Url: https://codereview.chromium.org/2853423002 .
Copy the Kernel string offsets into a uint32 array in the VM's heap.
This avoids allocating small string objects with new and avoids having
a table of the canonical strings.
Instead of an offset and a size, strings are now represented as
indexes into the string table in the heap. The start offset of string
N is found at byte offset N*4 because it is a uint32, and the end
offset is found at byte offset (N+1)*4. The strings themselves are
just integer indexes instead of pointers.
In the stream flow graph builder, string access is all random access.
R=jensj@google.com, vegorov@google.com
Review-Url: https://codereview.chromium.org/2852943003 .
1. A --platform flag is added to dart to give a path to a Kernel
binary for the platform libraries (as produced by building the
runtime_kernel target).
2. This binary is used for bootstrapping. Since it contains libraries
other then the VM's bootstrap libraries, they are also loaded.
3. The frontend does not send any library with a dart: import URI
scheme. Note that it does not (yet) prune the canonical name
table, which will contain a lot of unnecessary names used for
internal linkages in the platform libraries.
4. There is a single dependency in the platform libraries on the
script: _getMainClosure in dart:_builtin. This is patched after
the script is loaded.
BUG=
R=ahe@google.com, kustermann@google.com, vegorov@google.com
Review-Url: https://codereview.chromium.org/2786083002 .
- Instead of a pointer to new'd memory, Kernel strings now have an
offset from the start of the string data.
- When the streaming reader encounters the string data it records the
offset from the start of the binary. This offset is stored in the
Kernel Program and is used to compute the offset for strings.
- When a KernelReader is constructed, the string data is copied into a
Uint8 array in the VM's heap.
- A pointer to the string data is put into every Kernel script so it
can be used for constructing VM strings at compile time.
The source table does not use Kernel strings any more because those
strings are not found in the raw string data. Instead, the source
table uses new'd buffers for strings (but this will be cleaned up
separately).
R=jensj@google.com
Review-Url: https://codereview.chromium.org/2820363002 .
Instead of a list of strings given by their length and UTF-8 encoding,
restructure the string table to consist of a list of string ending
offsets followed by a blob of UTF-8 encoded strings without lengths.
This is a step toward copying the string blob into the VM's heap and
building a heap-allocated structure to give random access to them.
BUG=
R=asgerf@google.com, jensj@google.com
Review-Url: https://codereview.chromium.org/2790073004 .
Before: Canonical names contained pointers to the corresponding Kernel
tree which assumed that the whole tree was in memory whenever the
canonical names were.
Now: Canonical names do not contain these pointers. They were only
really used to perform name-based lookup in the VM's heap so the
canonical name itself is enough.
If we later find that we need to get from a canonical name to its
Kernel tree we can add an offset in the binary (for instance) to the
canonical name or in a separate mapping on the side.
BUG=
R=asgerf@google.com, jensj@google.com, vegorov@google.com
Committed: https://github.com/dart-lang/sdk/commit/ed77783cd32d55fdad61bf9bc749030847ba9384
Review-Url: https://codereview.chromium.org/2781893004 .
Before: Canonical names contained pointers to the corresponding Kernel
tree which assumed that the whole tree was in memory whenever the
canonical names were.
Now: Canonical names do not contain these pointers. They were only
really used to perform name-based lookup in the VM's heap so the
canonical name itself is enough.
If we later find that we need to get from a canonical name to its
Kernel tree we can add an offset in the binary (for instance) to the
canonical name or in a separate mapping on the side.
BUG=
R=asgerf@google.com, vegorov@google.com
Review-Url: https://codereview.chromium.org/2781893004 .
For compiling the platform libraries separately and for hot reload, we
will not link canonical names of Kernel libraries, classes, and
members to their Kernel definitions. Those definitions will not be
persistent.
As a first step, change name-based lookup of libraries and classes to
be be based on the canonical name instead of the Kernel definition.
BUG=
R=kustermann@google.com
Review-Url: https://codereview.chromium.org/2762213002 .
- Offsets on more stuff
- Status file for kernel
-> Testing with (before fasta)
```
python tools/test.py -mrelease -cdartk --no-tree-shake --no-dfe service
```
now shows everything as passing.
Reload stuff, and evaluation stuff (e.g.) has been disabled though.
- Lots of new service tests that tests what positions we stop at when
saying next.
As fasta has now landed debugging does not currently work, but this is still needed in order to both test better and allow for proper kernel debugging support.
R=hausner@google.com, kmillikin@google.com
Review-Url: https://codereview.chromium.org/2680303002 .
This adds a class CanonicalName that can represent a library, class,
or member. All references now go through a Reference object, which is
linked to both the AST node and its CanonicalName, so either can be
created first.
dartk now accepts multiple input files:
- If multiple dart files are given, they are all compiled.
- If multiple binaries are given, they are linked together.
Mixed dart and binary input is not supported by dartk.
dartk now has a flag --include-sdk which includes the entire SDK in
the output. This is so the SDK can be compiled alone and then linked.
Example of compiling separately and then linking:
dartk foo.dart -o foo.dill
dartk main.dart -o main.dill
dartk --include-sdk -o sdk.dill
dartk main.dill foo.dill sdk.dill --target=vm --link -o program.dill
dartk still has incredibly slow cold start due to the analyzer loading
the dart sdk, so this does not actually speed things up at the moment.
BUG=
R=ahe@google.com, kmillikin@google.com, kustermann@google.com, sigmund@google.com
Review-Url: https://codereview.chromium.org/2665723002 .
Previously a functions debuggable field was set to false in the async transformation (and because it wasn't done yet, not in async* and sync* transformation, though it should have been). Now instead, set the original async status and set debuggable on the c++ side equivalently.
Also, on the c++ side, set a functions modifier to async etc if they were originally async etc.
BUG=
R=asgerf@google.com, kmillikin@google.com, kustermann@google.com
Review-Url: https://codereview.chromium.org/2697193008 .
Jens Johansen