commit 7b50b7a8e650035c435c4d48abdc4ba90206df9e
author Alexander Markov <alexmarkov@google.com> Wed Jun 26 18:25:26 2019 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Wed Jun 26 18:25:26 2019 +0000
tree 03b6687d9b68433cf0330fd04a53df2ce183db8d
parent c1c24c2e192c45792e08217337a01e1d60fc224d

[vm/bytecode] Bootstrapping VM from bytecode

Previously, core snapshot was generated from AST
(because --enable-interpreter/--use-bytecode-compiler was not specified
when building core snapshot).

As the result, CL
https://dart.googlesource.com/sdk/+/da8cb470cc94830a98d49532e8d5d1a5b3d80f8b
which declared libraries in bytecode also removed bytecode entirely from
core snapshot in Dart SDK.

This CL enables bytecode by default if --bytecode argument is
specified for gn.py. This enables JIT compiler from bytecode
(interpreter is still disabled by default but can be enabled
using --enable-interpreter). Core snapshot and other
snapshots now have bytecode.

This change revealed a bunch of bugs which are fixed in this CL:

* _Closure fields were treated as unboxing candidates which triggered
  assertion in LoadFieldTOS in interpreter.

* Several places should load class declarations if they are not loaded yet.

* Canonicalization of TypeRef objects which are not fully initialized
  may cause duplicate entries in the hash table of canonical
  TypeArguments. This triggers assertions when hash table is rehashed.
  The solution is to avoid canonicalization of non-root recursive types
  and recursive type arguments. Also, TypeRef::Canonicalize and
  TypeRef::Hash are reverted to assert and work only if type was set.

* Native wrapper classes are eagerly stamped as type-finalized
  which caused assertion failures when reading their class declarations
  from bytecode.

* When building flow graph for FFI trampolines kernel offset of library
  (which is now declared in bytecode) was queried. Added special case
  to Function::KernelDataProgramOffset().

* In interpreter-only mode with simulator (e.g. SIMARM64) if simulator
  is not called before code is interrupted with stack overflow check,
  simulator returns get_sp() = 0, which was treated as stack overflow.

* test standalone_2/io/platform_resolved_executable_test.dart
  spawns sub-process but it didn't pass VM options.

Change-Id: I81bc4f1a4c6725cfa246a435ebe5d8abe43abc67
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107199
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Régis Crelier <regis@google.com>