An arm's field check can run a getter that changes the discriminant. The
checked cast now reads the discriminant again after each failed arm;
when its case changed, the tests continue arm by arm after the failed
arm, so the cast picks the arm the arm-by-arm tests pick.
The sanitized self-hosting native-frontend build needs about 15 GB by
itself: its clang compile of the whole frontend under ASan peaks at
10.5 GB beside a 3.8 GB compile in Node. In the 14 GB scope, with the
shard's other work running beside it, the kernel killed that clang
intermittently, so SC5004 reported clang's warnings and no error (SAN
16/20 and 19/20). The scope now caps RAM at 15 GB, still below the
runner's 16 GB, and may still swap past it.
A union parameter's proof covered the union, not its payload: narrowing it
and storing, returning or pushing the result, a narrowed nullish read, and a
store into a nullable-pointer field all counted as projections. That holds
for a boxed union, whose payload is a separate object. A record passed
through a nullable-pointer union is that payload, so forwarding it to such a
callee let a record in its caller's frame escape the frame.
A pointer-wrapped argument now needs a second fact from the callee's union
parameter: its payload stays in place too. The payload is in place when it
is only tested, narrowed for a field read (directly or through the checked
narrowing a field read of a `T | undefined` parameter compiles to), or passed
on to a parameter that is proved in turn. The facts that other arguments use
are unchanged.
Corpus 7663 has callees that push (directly and through a non-null
assertion), default, store in a global record field or a class field, or
pass on the narrowed record, and one that only reads it.
A JavaScript module binding whose initializer joins an untyped value with
a string, number or boolean through `||`, `&&`, `??` or `?:`
(`export const APP_NAME = pkg.appConfig?.name || "app"`) stayed a local of
the module's initializer, so reads from other modules and functions
failed with "a binding form with no lowering". Such initializers now
register the binding in checked-dynamic module storage, like the untyped
initializers they combine.
pi-coding-agent's config.js declares APP_NAME, APP_TITLE and isBundledNode
this way.
Refs #1777.
An `export * from` declaration binds each re-exported name to the binding
of the module that declares it, like a named re-export, so it has no
initialization state of its own. Import cycles whose modules re-export
another member of the cycle this way now compile with the exact cycle
initialization: re-exported names read the same values, and throw the
same temporal dead zone errors, as in Node. `export * as ns` of a cycle
member keeps the SC1016 refusal.
pi-coding-agent's sdk.js (sdk.js → agent-session-runtime.js →
agent-session-services.js → sdk.js) has this shape.
Refs #1777.
Object.getPrototypeOf of an Error answers Error.prototype when the error's view was built from its fields and its prototype is still the object the view was built with. After Object.setPrototypeOf(error, {}), it answers the object that was set.
A quotient x / Math.pow(2, n) divided on every evaluation, and a
division's latency bounds loops that carry the quotient, such as a key
that keeps its low bits with k - Math.floor(k / Math.pow(2, n)) *
Math.pow(2, n). A divisor that is a positive power of two from 2^-1022
to 2^1022 has a reciprocal that is a power of two too, whose bits are
0x7FE0000000000000 minus the divisor's, and the product with it is the
quotient for every dividend. The quotient now multiplies by that
reciprocal when the divisor's bits are such a power, and divides
otherwise.
Corpus 8180 compares the quotient with an ordinary division for every
integer exponent from -1080 to 1030, including divisors that are
subnormal, zero or infinite, and for exponents that are not integers.
A checked cast into a union whose discriminant has four or more string
literals reads the discriminant field once (scr_dyn_discriminant_case)
and then tests only the arms whose literal it holds and the arms without
a literal, in the union's arm order. Every other arm's literal test would
fail, so the arm chosen and the error for a value no arm matches are
unchanged. A typed capsule, an accessor or an inherited discriminant
still takes the tests arm by arm. Unions with fewer literals emit the
same code as before.
`t[i]!` on a typed array always took the numeric element read, which is NaN
for an index outside the array. Node reads undefined there, so `t[n]! ===
t[n]!` was false instead of true, `${t[n]!}` was "NaN", and `typeof t[n]!`
was "number".
`t[i]!` now takes the numeric read only where its use converts the value to
a number. Where the use tells undefined from NaN (an equality, a template
span, `+` with a string, a comparison with a string, `!`, `typeof`, an array
literal element, or an argument whose parameter admits undefined, such as
`Object.is` and `String`), it reads undefined for an invalid index, like
`t[i]`. Returns and plain bindings keep the numeric read.
Corpus 7394.
An expected regex or string read from a JavaScript object literal's
field is a checked-dynamic value while its checker type is RegExp or
string. assert.throws chose its regex comparison from the checker type
and passed the value unconverted, an internal compiler error, and
assert.match and the expected-object form refused it. Such a value now
converts to the regex or string its type names.
The checker resolves an overloaded call whose argument is `any` to the
first overload that argument satisfies, but in JavaScript the value can
select another one: generateKeyPairSync("ec", options) returns KeyObjects
or PEM strings by the options, and digest(encoding) returns a Buffer when
the encoding is undefined. The result was converted to the first
overload's return type, so such calls threw a TypeError where Node
returns the other overload's value.
When a checked-dynamic argument could take another overload whose return
type differs (trailing untyped or undefined arguments may also be
absent), the call's result in a JavaScript source is checked-dynamic. So
are the unannotated bindings it initializes, destructured or not, and
the unannotated functions that return it. fs.globSync keeps choosing its
result form from the resolved overload, since the runtime checks that
withFileTypes agrees with it.
Chris Tate