While initialization common runtime objects like functions, prototypes,
etc, we don't really care about tracking transitions for each and every
property added to them.
This patch puts objects into a "disable transitions" mode while we call
initialize() on them. After that, adding more properties will cause new
transitions to be generated and added to the chain.
This gives a ~10% speed-up on test-js. :^)
When reifying a shape transition chain, look for the nearest previous
shape in the transition chain that has a property table already, and
use that as the starting point.
This achieves two things:
1. We do less work when reifying property tables that already have
partial property tables earlier in the chain.
2. This enables adding properties to a shape without performing a
transition. This will be useful for initializing runtime objects
with way fewer allocations. See next patch. :^)
The check for invalid lhs and assignment to eval/arguments in strict
mode should happen for all kinds of assignment expressions, not just
AssignmentOp::Assignment.
So far we have three different syntax highlighters for LibJS:
- js's Line::Editor stylization
- JS::MarkupGenerator
- GUI::JSSyntaxHighlighter
This not only caused repetition of most token types in each highlighter
but also a lot of inconsistency regarding the styling of certain tokens:
- JSSyntaxHighlighter was considering TokenType::Period to be an
operator whereas MarkupGenerator categorized it as punctuation.
- MarkupGenerator was considering TokenType::{Break,Case,Continue,
Default,Switch,With} control keywords whereas JSSyntaxHighlighter just
disregarded them
- MarkupGenerator considered some future reserved keywords invalid and
others not. JSSyntaxHighlighter and js disregarded most
Adding a new token type meant adding it to ENUMERATE_JS_TOKENS as well
as each individual highlighter's switch/case construct.
I added a TokenCategory enum, and each TokenType is now associated to a
certain category, which the syntax highlighters then can use for styling
rather than operating on the token type directly. This also makes
changing a token's category everywhere easier, should we need to do that
(e.g. I decided to make TokenType::{Period,QuestionMarkPeriod}
TokenCategory::Operator for now, but we might want to change them to
Punctuation.
There's no point in trying to achieve shape sharing for global objects,
so we can simply make the shape unique from the start and avoid making
a transition chain.
Previously whenever you would ask a Shape how many properties it had,
it would reify the property table into a HashMap and use HashMap::size()
to answer the question.
This can be a huge waste of time if we don't need the property table for
anything else, so this patch implements property count tracking in a
separate integer member of Shape. :^)
Since blocks can't be strict by themselves, it makes no sense for them
to store whether or not they are strict. Strict-ness is now stored in
the Program and FunctionNode ASTNodes. Fixes issue #3641
When scanning for potential heap pointers during conservative GC,
we look for any value that is an address somewhere inside a heap cell.
However, we were failing to account for the slack at the end of a
block (which occurs whenever the block storage size isn't an exact
multiple of the cell size.) Pointers inside the trailing slack were
misidentified as pointers into "last_cell+1".
Instead of skipping over them, we would treat this garbage data as a
live cell and try to mark it. I believe this is the test-js crash that
has been terrorizing Travis for a while. :^)
Each JS global object has its own "console", so it makes more sense to
store it in GlobalObject.
We'll need some smartness later to bundle up console messages from all
the different frames that make up a page later, but this works for now.
