This PR avoids false-positive error messages on specialization
restrictions under the module system when the declaration is explicitly
marked as not specializable. It could also provide some minor public
size and rebuild savings.
This PR ports the toposorting pass from IR to LCNF.
We can already do this now as the remaining IR pipeline does not insert
any new auxiliary
declarations into the SCC so now is as good a time as ever to do it.
This PR ensures that failure in initial compilation marks the relevant
definitions as `noncomputable`, inside and outside `noncomputable
section`, so that follow-up errors/noncomputable markings are detected
in initial compilation as well instead of somewhere down the pipeline.
This may require additional `noncomputable` markers on definitions that
depend on definitions inside `noncomputable section` but accidentally
passed the new computability check.
Reported at
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/Cryptic.20error.20message.20in.20new.20lean.20toolchain.3F.
This PR removes the type correction heuristic from the RC pass as it is
already present in the
boxing pass. Previously the boxing pass did not try to correct types so
the RC pass did. We
discovered issues with not doing this in the boxing pass and
accidentally maintained two corrections
for a while. This PR merges both and removes the one from RC.
This PR makes the derived value analysis in RC insertion recognize
`Array.uget` as another kind of
"projection-like" operation. This allows it to reduce reference count
pressure on elements accessed
through uget.
This PR implements lazy initialization of closed terms. Previous work
has already made sure that ~70% of the closed terms occurring in core
can be statically initialized from the binary. With this the remaining
ones are initialized lazily instead of at startup.
For this we implement a small statically initializable lock that goes
with each term. When trying to access the term we quickly check a flag
to say whether it has already been initialized. If not we take the lock
and initialize it, otherwise we dereference the pointer and fetch the
value.
This PR ports the RC insertion from IR to LCNF.
In doing so it makes the entire code monadic as opposed to simulating a
ReaderT StateRefT stack manually.
This PR renames `instance_reducible` to `implicit_reducible` and adds a
new
`backward.isDefEq.implicitBump` option to prepare for treating all
implicit
arguments uniformly during definitional equality checking.
## Changes
**Rename `instance_reducible` → `implicit_reducible`:**
- Rename `ReducibilityStatus.instanceReducible` constructor to
`implicitReducible`
- Register new `[implicit_reducible]` attribute, keep
`[instance_reducible]` as alias
- Rename `isInstanceReducible` → `isImplicitReducible` (with deprecated
aliases)
- Update all references across src/ and tests/
The rename reflects that this reducibility level is used not just for
instances
but for any definition that needs unfolding during implicit argument
resolution
(e.g., `Nat.add`, `Array.size`).
**Add `backward.isDefEq.implicitBump` option:**
- When `true` (+ `respectTransparency`), bumps transparency to
`.instances` for
ALL implicit arguments in `isDefEqArgs`, not just instance-implicit ones
- Defaults to `false` for staging compatibility — will be flipped to
`true` after
stage0 update
- Adds `// update me!` to `stage0/src/stdlib_flags.h` to trigger CI
stage0 update
## Follow-up (after stage0 update)
- Flip `backward.isDefEq.implicitBump` default to `true`
- Fix resulting test/module failures
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR ensures the type resolution cache properly caches results for
type classe containing output parameters.
It ensures the cache key for a query like
```
HAppend.{0, 0, ?u} (BitVec 8) (BitVec 8) ?m
```
should be independent of the specific metavariable IDs in output
parameter positions. To achieve this, output parameter arguments are
erased from the cache key. Universe levels that only appear in output
parameter types (e.g., ?u corresponding to the result type's universe)
must also be erased to avoid cache misses when the same query is issued
with different universe metavariable IDs.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
This PR verifies all of the `String` iterators except for the bytes
iterator by relating them to `String.toList`.
Along the way we define `String.posLE` and `String.posLT` analogously to
`String.posGE` and `String.posGT` and redefine `String.prev` to go
through `String.posLT`.
We also define and verify `String.positionsFrom` and
`String.revPositionsFrom`, which are the obvious generaliziations of
`String.positions` and `String.revPositions` starting at a positions
other than the start/end.
Finally, we get various lemmas about strings and positions, including
some nice induction principles `String.Pos.next_induction` and
`String.Pos.prev_induction`.
Of course, we also have all of the analogous results for `String.Slice`.
This is a mitigation for the fact that the upfront noncomputable checker
currently doesn't error out early enough in certain situations so we
violate invariants later on.
This PR adds a simplification rule for `Task.get (Task.pure x) = x` into
the LCNF simplifier. This
ensures that we avoid touching the runtime for a `Task` that instantly
gets destructed anyways.
This PR uses `getImpureSignature?` instead of the `findEnvDecl` from IR
in the LCNF compiler. We
were previously still relying on the IR function because only IR
contained proper borrow
annotations. Now we infer the borrow annotations on the LCNF level and
can thus use the LCNF
signatures.
This PR fixes an issue in LCNF simp where it would attempt to act on
type incorrect `cases`
statements and look for a branch, otherwise panic. This issue did not
yet manifest in production as
various other invariants upheld by LCNF simp help mask it but will start
to become an issue with the
upcoming changes.
This is the proper fix for #6957.
This PR changes the semantics of `inline` annotations in the compiler.
The behavior of the original `@[inline]` attribute remains the same but
the function `inline` now comes with a restriction that it can only use
declarations that are local to the current module. This comes as a
preparation to pulling the compiler out into a separate process.
Closes: #12334
This PR changes the handling of over-applied cases expressions in
`ToLCNF` to avoid generating function declarations that are called
immediately. For example, `ToLCNF` previously produced this:
```lean-4
set_option trace.Compiler.init true
/--
trace: [Compiler.init] size: 4
def test x y : Bool :=
fun _y.1 _y.2 : Bool :=
cases x : Bool
| PUnit.unit =>
fun _f.3 a : Bool :=
return a;
let _x.4 := _f.3 _y.2;
return _x.4;
let _x.5 := _y.1 y;
return _x.5
-/
#guard_msgs in
def test (x : Unit) (y : Bool) : Bool :=
x.casesOn (fun a => a) y
```
which is now simplified to
```lean-4
set_option trace.Compiler.init true
/--
trace: [Compiler.init] size: 3
def test x y : Bool :=
cases x : Bool
| PUnit.unit =>
let a := y;
return a
-/
#guard_msgs in
def test (x : Unit) (y : Bool) : Bool :=
x.casesOn (fun a => a) y
```
This is especially relevant for #8309 because there `dite` is defined as
an over-applied `Bool.casesOn`.
This adds `set_option debug.byAsSorry true` and `decreasing_by sorry` to
various files to allow bootstrapping with Config structure changes. These
changes will be restored after the bootstrap dance is complete.
This PR shifts the conversion from LCNF mono to lambda pure into the
LCNF impure phase. This is preparatory work for the upcoming refactor of
IR into LCNF impure.
The LCNF impure phase differs from the other LCNF phases in two crucial
ways:
1. I decided to have `Decl.type` be the result type as opposed to an
arrows from the parameter types to the result type. This is done because
impure does not have a notion of arrows anymore so keeping them around
for this one particular purpose would be slightly odd.
2. In order to avoid cluttering up the olean size LCNF impure saves only
the signature persistently to the disk. This is possible because we no
longer have inlining/specialization at this point of compilation so all
we need is typing information (and potentially other environment
extensions) to guide our analyses.
This PR adds the new transparency setting `@[instance_reducible]`. We
used to check whether a declaration had `instance` reducibility by using
the `isInstance` predicate. However, this was not a robust solution
because:
- We have scoped instances, and `isInstance` returns `true` only if the
scope is active.
- We have auxiliary declarations used to construct instances manually,
such as:
```lean
def lt_wfRel : WellFoundedRelation Nat
```
`isInstance` also returns `false` for this kind of declaration.
In both cases, the declaration may be (or may have been) used to
construct an instance, but `isInstance`
returns `false`. Thus, we claim it is a mistake to check the
reducibility status using `isInstance`.
`isInstance` indicates whether a declaration is available for the type
class resolution mechanism,
not its transparency status.
**We are decoupling whether a declaration is available for type class
resolution from its transparency status.**
**Remak**: We need a update stage0 to complete this feature.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR gives a simpler semantics to `noncomputable`, improving
predictability as well as preparing codegen to be moved into a separate
build step without breaking immediate generation of error messages.
Specifically, `noncomputable` is now needed whenever an axiom or another
`noncomputable` def is used by a def except for the following special
cases:
* uses inside proofs, types, type formers, and constructor arguments
corresponding to (fixed) inductive parameters are ignored
* uses of functions marked `@[extern]/@[implemented_by]/@[csimp]` are
ignored
* for applications of a function marked `@[macro_inline]`,
noncomputability of the inlining is instead inspected
# Breaking change
After this change, more `noncomputable` annotations than before may be
required in exchange for improved future stability.
This PR introduces a phase separation to the LCNF IR. This is a
preparation for the merge of
the old `Lean.Compiler.IR` and the new `Lean.Compiler.LCNF` framework.
The change parametrizes all relevant `LCNF` data structures over a
`Purity` parameter and
additionally carries around proofs that the `Purity` has certain values,
depending on what's
required. This is done as opposed to indexing the types over `Purity`
because we do (almost) never
have to store the `Purity` value for phase generic structures this way.
This PR reverts a lot of the changes done in #8308. We practically
encountered situations such as:
```
fun y (z) :=
let x := inst
mkInst x z
f y
```
Where the instance puller turns it into:
```
let x := inst
fun y (z) :=
mkInst x z
f y
```
The current heuristic now discovers `x` being in scope at the call site
of `f` and being used under a binder in `y` and thus blocks pulling in
`x` to the specialization, abstracting over an instance.
According to @zwarich this was done at the time either due to observed
stack overflows or pulling in computation into loops. With the current
configuration for abstraction in specialization it seems rather unlikely
that we pull in a non trivial computation into a loop with this. We also
practically didn't observe stack overflows in our tests or benchmarks.
Cameron speculates that the issues he observed might've been fixed
otherwise by now.
Crucial note: Deciding not to abstract over ground terms *might* cause
us to pull in computationally intensive ground terms into a loop. We
could decide to weaken this to just instance terms though of course even
computing instances might end up being non-trivial.
This PR removes the LCNF testing framework. Unfortunately it never got
used much and porting it to
the extended LCNF structure now would be a bit of effort that would
ultimately be in vain.
