Move Kernel strings into the VM's heap.

Move Kernel strings into the VM's heap.

- 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

Committed: https://github.com/dart-lang/sdk/commit/2e794c4e16a839afc0664c20e142eb82ccf9be7e

[Kevin Millikin (Google), 2017-04-18 13:41:02]

kmillikin@google.com changed reviewers:
+ jensj@google.com, kustermann@google.com

[Kevin Millikin (Google), 2017-04-18 13:41:02]

This is a step toward moving the Kernel strings, canonical names, and method
bodies into the VM's heap where their memory can be managed.

[jensj, 2017-04-19 06:41:01]

lgtm

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary.cc
File runtime/vm/kernel_binary.cc (right):

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary.cc...
runtime/vm/kernel_binary.cc:181: uint8_t* buffer = new uint8_t[length];
nit: "buffer" is probably not the greatest name.

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary_fl...
File runtime/vm/kernel_binary_flowgraph.cc (right):

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary_fl...
runtime/vm/kernel_binary_flowgraph.cc:350: for (intptr_t i = 0; i < list_length;
++i) {
Maybe we should look at how much it would cost in terms of binary size to always
use 4 bytes for these integers, which would allow us to skip the whole thing
without the loop.

[Kevin Millikin (Google), 2017-04-21 08:22:12]

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary.cc
File runtime/vm/kernel_binary.cc (right):

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary.cc...
runtime/vm/kernel_binary.cc:181: uint8_t* buffer = new uint8_t[length];
On 2017/04/19 06:41:01, jensj wrote:
> nit: "buffer" is probably not the greatest name.

OK.  string_buffer.

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary_fl...
File runtime/vm/kernel_binary_flowgraph.cc (right):

https://codereview.chromium.org/2820363002/diff/1/runtime/vm/kernel_binary_fl...
runtime/vm/kernel_binary_flowgraph.cc:350: for (intptr_t i = 0; i < list_length;
++i) {
On 2017/04/19 06:41:01, jensj wrote:
> Maybe we should look at how much it would cost in terms of binary size to
always
> use 4 bytes for these integers, which would allow us to skip the whole thing
> without the loop.

Acknowledged.

[Kevin Millikin (Google), 2017-04-21 08:32:55]

Description was changed from

==========
Move Kernel strings into the VM's heap.

- 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).
==========

to

==========
Move Kernel strings into the VM's heap.

- 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

Committed:
https://github.com/dart-lang/sdk/commit/2e794c4e16a839afc0664c20e142eb82ccf9be7e
==========

[Kevin Millikin (Google), 2017-04-21 08:32:56]

Committed patchset #2 (id:20001) manually as
2e794c4e16a839afc0664c20e142eb82ccf9be7e (presubmit successful).