Stage L3 of the localized-failure design.
A degraded type used to become the checked dynamic as a whole slot. Its
lenient mapping now keeps the compilable shape: the type maps again with
every nested component whose mapping fails as the checked dynamic, so a
record keeps its static members with one dynamic member, an array of
records keeps its records, and a Map, Promise or function keeps its static
parts. When even that shape does not map, or a unit still fails with it,
the type falls back to the whole-slot checked dynamic (one more round).
Lenient forms are IR types of one lowerer's shape tables, so the coverage
remainder re-derives them. A pushed-down type is one SC6104, at the slot
where it degraded, marked as keeping its shape.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A function expression's or arrow's parameter and return types commit at the
statement that holds it, and a generic instance's at the instance drain.
Both are now localized-failure commit points for declaration slots: the
failing type degrades and the statement or instance lowers again.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A flush inside a capture buffer cannot retry (a probe that later declines
must see today's answer), so its copies of the declaration's diagnostics
reach the build when the statement commits. That statement commit point
now reopens such a declaration: when its diagnostics are retriable, they
leave the build, the declaration retries, and the statement lowers again.
Probe copies of a declaration that already registered are dropped.
The 'any'-typed class field refusal stays a fence at collection and is
lifted by the flush retry, so only reached classes change; the coverage
remainder registers the declarations reachable emit registered, and maps
the degraded types alike.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Stage L2 of the localized-failure design.
A class whose field (or parameter property) type has no static lowering,
or a function or method whose parameter or return type has none, used to
be rejected, and every use of it failed on its own line. Its collection
deferred the diagnostics until a reachable reference flushed them into the
build. That flush is now a commit point: when every deferred diagnostic is
a degradable type failure at one of the declaration's slots, the failing
types degrade and the collection runs again, up to 16 rounds. The
declaration registers with checked dynamic slots (one SC6104 each), the
reference proceeds, and emitReachable (or run) lowers the bodies it had
skipped. A derived class whose base registers this way retries with it.
The 'any'-typed class field refusal is lifted: a TypeScript class field
whose type maps to the checked dynamic stores it, as JavaScript classes
already do.
A program that compiles today flushes no deferred diagnostics into its
build, so nothing degrades and its output is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Its programs pin today's refusals; localized failure turns several of them
into checked dynamic slots in the default mode. Under static-only every
snapshot stays byte-identical, which is the stage's proof that the switch
restores the refusals.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Stage L1 of the localized-failure design.
A local, loop variable or module global whose declared TypeScript type has
no static lowering used to reject its declaration statement, and every
later use of the binding failed with it. Where that failure is about to
enter the build (the statement's poison in a TypeScript file, or the
module global's registration), the failing type now joins the lowerer's
degraded types and the unit lowers again: the type maps to the checked
dynamic wherever its strict mapping fails, so the slot holds values by
reference (typed capsules, live records and arrays, function thunks) and
typed reads out of it are checked. Each such slot is an SC6104
performance warning, listed under coverage's statement counts and in the
JSON envelope; coverage --fail-on=dynamic-slots fails on them, and
--tier=static-only keeps today's refusals.
A program that compiles today reaches neither commit point, so nothing
degrades and its output is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Stage L0 of the localized-failure design, report-only: no lowering changes.
A type with no static lowering poisons the slot that holds it, and the
poison rejects the declaration around it (a class, a signature, a
declaration statement); each later use then fails on its own line. This
records, on the committed diagnostics, where each type failure sits, whether
a checked dynamic slot would keep the program's meaning, and which rejected
declarations each failing statement used. coverage --explain-dynamic turns
that into the would-be dynamic slot list with the cascade each slot clears,
and the counts of errors that would disappear through stages L2 and L4.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Parallel changes kept taking the same next corpus number (6992 twice, the
Node island programs renumbered several times). The harness never needed
the numbers: it discovers every entry by glob, and 818 programs already
have descriptive names. AGENTS.md now makes a name, without a number, the
convention for new programs and keeps the numbered ones as they are.
The two scripts that sampled programs by number skipped named programs.
They now key a named program by a stable hash of its name, so they sample
it at the same rate; the numbered programs they pick are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A union with a checked-dynamic arm (`unknown`, fetch's AbortSignal)
maps to the checked-dynamic value when every other arm is one the
checked-dynamic tree holds faithfully. Function arms were excluded, so
`Progress | AbortSignal | undefined` was refused (SC2009).
The tree boxes a function whose parameters check in and whose result
converts out by reference (canBoxFuncIntoDyn), and `typeof x ===
"function"` narrows it back out to the typed function. Such arms now
join the collapse. The corpus program checks calls, identity (`===`
against the original), and the other arm's members against Node.
pi's SessionManager.listAll takes `onProgressOrSignal?: SessionListProgress
| AbortSignal`. The refusal rejected the whole SessionManager class.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
libunicode composes an LV syllable with U+11A7 as if it were a trailing
consonant (U+11A8..U+11C2), which drops it: "가ᆧ".normalize()
gave "가" where Node gives "가ᆧ". U+11A7 is a class-0 vowel
that composes with nothing, so for the composing forms the code points
between occurrences of it normalize on their own and it is kept as it
is. The guard sits in front of the vendored library (scr_unicode_normalize),
for String.prototype.normalize and the NFC step of IDNA mapping.
8009-normalize-hangul-jungseong-o-yae prints the code points of all four
forms for U+11A7 after LV and LVT syllables, conjoining jamo, other
starters and combining marks.
The range analysis caps a counter that steps by 1 at 2^53, where
`j + 1 === j`, so a loop such as `for (let j = 2 ** 53 - 2;
j < 2 ** 53 + 10; j++)` has a range of three values at its condition and
was taken for a loop of three runs. It never ends, and without its poll
worker.terminate() could not stop it. A loop's runs now count as bounded
only when a step from every value in its counter's range gives a
different value.
A number-key Map or Set read whose key has an integer view
(sc_map_entry_f64_int) fell back to the same hashed probe as any double
key, which tests for NaN and -0 before hashing. The fallback is now
sc_map_entry_f64_hashed_int, which takes the integer and converts it to
the key word directly: an integer is never NaN, and zero converts to +0.
Both hashed probes test the absent-key filter only before scanning a map
that keeps no bucket table. The filter keeps two of its 64 bits per key,
so it rejects few absent keys once a map has a bucket table, and the
probe's first bucket read answers those.
The map layout and the runtime lookup are unchanged. Corpus 8331 covers
integers the compiler tracks as integers on hashed maps and absent keys on
small bucket tables, and matches Node's output.
A promise converted into a union's promise arm is a new promise, so two
optional slots set to one promise each hold their own conversion, and a
value narrowed out of such a slot may be one too. Union equality compared
those arm payloads by pointer and answered false where Node answers true.
Any comparison between a union with a promise arm and a promise or another
such union now compares both sides as untyped values, where a converted
promise answers with its origin's identity.
JavaScript sources hold node:util's MIMEType and MIMEParams as identity
tokens, so a read such as MIMEType.prototype or MIMEType.name answered
undefined where Node returns the class's member. Those reads now report
SC2020, as the TypeScript spelling does at compile time; in JavaScript
the refusal throws when the read runs.
The node24-mime-errors fixture reads MIMEType.prototype to take the
getters' descriptors, so its expected refusal is now SC2020.
The tsc gate (preflight's errorsOf, and the original program of a JSX or
declaration-projection build) asked for every file's semantic
diagnostics, then dropped all of those in an opted-in package's files, in
unselected package JavaScript and in package shims. With --npm-static
that is nearly the whole check: on three.js's nodes fixture the 82
package files took 1.17 s and reported 13,022 diagnostics, the program's
own files 0.1 s.
getPreEmitDiagnostics takes the files whose diagnostics its caller keeps.
When some file is left out, the server checks only the kept files
(getDiagnosticsOfCheckedFiles), and their semantic diagnostics come in
the full check's order. When a stored answer for the supplied
declaration files applies to the program, it stands in for checking
those files, as in the full check; the storage rule is unchanged. A
global diagnostic can come from checking any file, so when the partial
check reports one, the full check answers as before. At load time,
before workspace packages are known, the gate leaves out only package
and shim files.
The kept diagnostics are unchanged.
The test emits each corpus program from its serialized IR with its own
emitter options and compares the text with compile()'s. compile() now
marks functions sanitize_address only in sanitized builds, so the test
passes the same setting as objectAudit.
In a worker program, a loop inside another loop of the same function
needs less than its own budget, because the enclosing loop polls at
least once every 64 of its iterations:
- A loop whose counters' proven ranges bound its runs, and those of the
loops in its body, to 64 x 64 emits no poll. This covers loops with
constant bounds, such as mandelbrot's lane and iteration loops. The
bound uses the counted and two-counter loop ranges, or the range of a
counter that the update alone steps by a constant where the condition
reads it. Loops whose counted form needs a run-time guard don't count.
- An innermost counted loop is strip-mined like a counted loop over
typed arrays, whatever its body. A run of at most 64 iterations never
polls, and the budget's countdown leaves the body. A run of at most
16384 iterations is one block and polls once as it leaves. A longer
run polls between blocks of 64, but not after its last block.
Between two polls there are then at most 64 iterations of the enclosing
loop, and in each of them at most 16384 unpolled iterations of each
strip-mined inner loop and 64 x 64 runs of each bounded nest. A loop
that no other loop of its function encloses polls as before.
New corpus program: native-worker-terminate-bounded-loops.ts.
A Linux executable link runs `clang -fuse-ld=lld ...`, and the driver
only starts ld.lld with a job it derives from its arguments, its
environment and the installed toolchain. Starting the driver costs
about 10 ms of a small program's 29 ms link.
LinkerJobs (native/linker-job.ts) records that job in the native cache,
with the link's own inputs and output as positions. A traced link (the
Linux executable cache's `-v -Wl,-t` link) records it from the job line
the driver prints with -v; a link the executable cache does not trace
lists it with -v -### first. The entry also keeps the identities of the
files and directories the job and the driver's -v lines name (ld.lld,
startup objects, library directories, the GCC installation, the
driver's directory): the set the Linux executable cache records from its
traced link. It is keyed by the driver's identity, the link's
arguments, the toolchain environment, PATH and the working directory. A
later link with the same key whose recorded paths still have those
identities runs ld.lld with the job directly, and the executable cache
traces it with the job's -t output and the recorded identities.
Every other link runs through the driver as before: cross-target links,
links without lld, a driver that is not clang, SCRIPTC_LINKER, sanitizer
links, a toolchain environment that names mutable inputs, a listing
without exactly one ld.lld job naming each of the link's paths once, a
recorded path whose identity changed, and a job that fails (the driver
then reports the error). The linker gets the same arguments, so the
executables are identical.
The sanitized lane's -fsanitize=address link needs the attribute to
instrument the emitted functions. Without a sanitizer pass it is not
inert: LLVM does not shrink-wrap functions that carry it, so every call
saved and restored all of a function's callee-saved registers on entry,
including on paths that return before any call, and it blocks
speculative loads. The LLVM helper already dropped it for builds that
import runtime bitcode (speed); release builds kept it.
- The new sanitizeAttributes option (default true for direct emission)
is set from --sanitize wherever objectAudit is.
- Without it and without a target CPU level, attribute group #0 holds a
string attribute LLVM ignores, since a group cannot be empty.
The compiler compiles itself, and a Map keyed by another Map is outside
the key domains it compiles (SC2009 in the self-hosted frontend). The
Lowerer's table is now keyed by the declared alias reference: each entry
lists the instances that instantiate it with their ts-level bindings maps,
and the resolver picks the current instance's by identity.
