Commit Graph
42 Commits
Author SHA1 Message Date
Richard Smith c6d35e1c4a Rename template constant -> concrete constant. (#4939)
This implements a direction decided in a
[recent
discussion](https://docs.google.com/document/d/1Iut5f2TQBrtBNIduF4vJYOKfw7MbS8xH_J01_Q4e6Rk/edit?resourcekey=0-mc_vh5UzrzXfU4kO-3tOjA&tab=t.0#heading=h.mas1g68xx9ct)
to switch away from "template constant" when naming a constant that
doesn't depend on any generic parameters, because that creates confusion
with template-dependent constant values that depend on a template
parameter.
2025-02-12 21:24:51 +00:00
Richard SmithandJon Ross-Perkins fcfb1345d5 Support accessing associated functions by member access into facets (#4872)
For an expression such as `(Type as Interface).AssocFn()`, track the
`Self` type `Type` in the result of the member access so that it's
available when checking the function call.

This introduces a new kind of type, `ImplFunctionType`, that represents
the type of a function that is expected within an impl, modeled as the
type of the function within the interface plus a value to use as `Self`.
Calls to values of this type behave like calls to the underlying
function except that the `Self` parameter is pre-bound to the self type
from the facet.

In order to support this, fix an issue where the imported list of
generic bindings lost their association with their enclosing generic.
This adds a little complexity to `import_ref`, including a new recursive
cycle that I intend to address in a follow-up PR.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-02-04 22:38:38 +00:00
Richard Smith 5f888e1124 Treat associated constants as entities parameterized by Self (#4837)
Add a full entity representation for associated constants, and build a
`Generic` object for them. This `Generic` is parameterized by the
enclosing `Self` type, allowing the use of `Self` within the type of the
associated constant to be supported.

When performing impl lookup for an associated constant, produce the type
with the provided self type substituted for its `Self` along with any
generic parameters of the interface.

Split the handling of associated constant declarations into two parts,
corresponding to the code before the `=`, and the code between the `=`
and `;` (if any). The former goes into the generic declaration region;
the latter into the generic definition region. This prepares us to
handle the default value for an associated constant, but for now we're
just storing the information and not actually using it.

Remove the entity type field from `assoc_entity_type`, because it's
almost unused and is an attractive nuisance -- it must necessarily be a
type in the generic scope of the associated constant rather than in the
scope of the instruction (because there is no `Self` anywhere else),
which means that it's hard to substitute into or derive meaning from.

See `toolchain/check/testdata/impl/assoc_const_self.carbon` for tests of
the new functionality; these used to cause the toolchain to crash.
2025-01-25 02:13:52 +00:00
Jon Ross-Perkins 6b5eb1a101 Id::Invalid -> Id::None (#4834)
High level, replacing `Id::Invalid` with `Id::None` and `Id::is_valid`
with `Id::has_value` for clarity, as discussed
[here](https://discord.com/channels/655572317891461132/655578254970716160/1331664574545395794).
The `IntId` refactoring is needed together with `AnyIdBase` because it's
also used with `ValueStore`.

Note, trying to be careful not to rewrite `EnumBase::InvalidIndex`, or
`is_valid` in general (e.g., `IdKind::is_valid`).

I've tried to sequence commits here:

1. Automatic replacements:

- `((?:Id|Index)(?: |::|\(|Base(?:\(|::)))Invalid((?:Index)?\W)` ->
`$1None$2`
  - `<invalid>` -> `<none>`
  - `InvalidNodeId` -> `NoneNodeId`
  - `/\*invalid\*/` -> `/*none*/`
  - `id((?:_|\(\))(?:\.|->))is_valid` -> `id$1has_value`

2. Manual edits:

  - In `int.h` and `int_test.cpp`
    - `IntT` has `is_value`, which I'm renaming to `is_embedded_value`.
    - Manual edits to comments in this file.
  - `AnyIdBase` and `IdBase`
- Declaration of `is_valid` -> `has_value`, `InvalidIndex` ->
`NoneIndex`.
  - In `ids.h` and `ids.cpp`
    - `is_valid` -> `has_value`
- `// An explicitly invalid ID.` -> `// An ID with no value.`; similar
for index
    - Various math on `InvalidIndex` -> `NoneIndex`
    - Various mentions of "valid" in comments
  - In `value_store.h`, for `IdT::Invalid`, plus one comment
- In `impl.h` and `tokenized_buffer.h`, we had different initialization
of `::None` values (versus `ids.h` syntax) that I fixed manually.
  - Spot checks to compile
- Particularly where `is_valid` replacements didn't catch spots due to
different naming.

3. Autoupdate tests

4. verbose.carbon (NOAUTOUPDATE)

5. Comment spot checks

Note there are probably other mentions of "Invalid" that should be swept
up, but I'd like to argue for merging and separating out remaining
cleanup since this is so sweeping (and likely to hit merge conflicts
from churn). We'll probably have lingering mentions of "invalid" for a
bit regardless, just because there are uses of "invalid" in non-Id APIs.
2025-01-22 23:15:00 +00:00
Calvin 3f4de65ad8 Improve SemIR naming of import_refs (#4824)
Changes the name of SemIR `import_ref`s to use the format
`<package>.<entity>`.

<table>
<tr><th>Before</th><th>After</th></tr>
<tr>
<td><code>%import_ref.05a: type</code></td>
<td><code>%Main.D: type</code></td>
</tr>
<tr>
<td><code>%import_ref.8f2: &lt;witness&gt;</code></td>
<td><code>%Main.import_ref.8f2: &lt;witness&gt;</code></td>
</tr>
</table>

* [Discord discussion in
#toolchain](https://discord.com/channels/655572317891461132/655578254970716160/1330253540999827577)
* Closes #4769
2025-01-22 07:22:07 +00:00
David Blaikie 667a010ae6 Readd the missing class !members list. (#4828)
Thanks to danakj for spotting this was removed accidentally in #4732
2025-01-21 20:37:07 +00:00
Geoff RomerandRichard Smith 13434f0e8a Model var as a pattern operator (#4720)
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-01-17 17:51:34 +00:00
a8b46cf561 Add SemIR Vtable instruction and usage (#4732)
Add a Vtable typed inst with a type_id (of the type this vtable applies
to) and list of virtual function decls (or import refs to function
object constants).

This doesn't add lowering/emission of the vtable, or usage when
initializing objects of the type.

Some questions in case they're interesting to discuss:
* is it right/worth having the type_id in the vtable? (probably makes it
easier to emit - using the type to get the class name to figure out the
mangled name for the vtable) perhaps it should be a ClassId?
* I'm thinking the logic in CheckCompleteClassType could be the place we
handle diagnostics for mismatched keywords (virtual/abstract for a
function that's already virtual/abstract, maybe checking for non-virtual
functions with the same name in a base class, or derived class functions
without `impl`, etc) - but we could move some of that to the moment we
walk the function decl, and record our findings in the function decl
(record the base function it overrides, or the index of the vtable to
slot to use when building the vtable at the end of the class)
* the Vtable typed inst has `constant_kind = InstConstantKind::Always`
and `is_lowered = false`, I think I added that in to workaround/address
some failures in lowering. And seems correct for this intermediate step
- I'll add lowering in a follow-up patch. But the constant_kind - what
should this be? We can just say all vtables are of VtableType (in which
case the `Always` constant kind sounds right to me) or we could have
them introduce a type with each virtual function as a named member,
even?

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-01-16 20:19:22 +00:00
Dana Jansens 6aba386eeb Move the complete_witness_type above the !members label. (#4808)
When printing a Class, the complete_type_witness was printed last but
this gave a somewhat misleading representation as it appeared to be part
of the !members label. Move it above the label so that the label more
clearly refers to everything below it.
2025-01-15 22:13:19 +00:00
Richard Smith b1230218d5 Make fingerprinting stable across compatible source changes. (#4789)
Include the index rather than the name in the fingerprint of a symbolic
binding. While both the index and the name contribute to the canonical
identity, using either one of them in the fingerprint is sufficient to
ensure that distinct entities get different fingerprints. Changing the
name of a symbolic binding should ideally not result in fingerprint
changes, so exclude the name from the fingerprint when we have an index.

Use the canonical type and constraint when fingerprinting an impl, so
that uses of names in `name_ref` instructions aren't considered, only
the entity the name resolves to, and different ways of spelling the same
type have the same fingerprint. This similarly allows compatible changes
to be made to impls without changing the fingerprint.

Exclude the declaration block when determining the fingerprint of a
declaration. The declaration block contains the declarations of
parameters of the declaration, which do affect whether two declarations
are identical, but not whether they denote the same entity, because it
would be invalid to have different declaration blocks for declarations
with the same name in the same scope. Therefore changes to the
declaration block are compatible, and it's useful for such changes to
not affect the fingerprint.

This is not easy to test in isolation with our current testing
machinery. However, a follow-on PR will change the name of a parameter
in the prelude, and with this in place, will not cause any changes to
occur elsewhere in the toolchain tests.
2025-01-10 22:30:22 +00:00
Richard SmithandDana Jansens 19182f08aa Compute a fingerprint for constants and import_ref instructions. (#4763)
Use it in the instruction namer to make instruction names more stable
across unrelated changes to the toolchain or the prelude.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-01-07 20:41:44 +00:00
Dana Jansensandjonmeow 6cb660f5ad Avoid recursion in InstNamer::CollectNamesInBlock (#4706)
Use a deque to maintain the set of instructions to be walked over. so
that the loop can append more instructions (with their related scope)
during iteration without requiring recursion.

---------

Co-authored-by: jonmeow <jperkins@google.com>
2024-12-20 16:12:06 +00:00
Geoff RomerandRichard Smith a112cbde5c Model type expressions as regions (#4698)
This is a precondition for enabling the new pattern-matching subsystem
to support binding patterns that have `if` expressions in the type
position.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2024-12-19 21:41:06 +00:00
Richard Smith c1590f886a Add equality comparison support for bool. (#4701) 2024-12-18 00:47:03 +00:00
Jon Ross-Perkins e7a86b03c6 Remove offsets from InstId formatting, trying to name more (#4645)
The offsets were originally added to deal with churn from builtins in
the raw semir. In textual semir, we mostly see instruction IDs for
imports, and builtins have also settled down more.

On imports, where possible, use the `EntityNameId` for an import instead
of printing an instruction. Next, show the source location if we have a
node. Only show the instruction if there's no location.

This also exposes `Parse::Tree` and `TokenizedBuffer`, so that we can
pass a `SemIR::File` without the component parts. In particular this
allows us to get the `TokenizedBuffer` for import IRs without
substantial structural modifications. We may want to make these optional
for serialized `SemIR` later, but the nodes/tokens contain source
location, which we'd need for debug information -- so it's not clear how
much we can really make them optional without substantial information
loss.

Reduce arguments to just `File` in a few spots, as a result of the
accompanying `TokenizedBuffer` and `Parse::Tree`. Also updates style to
pass around `const File*` where the reference is maintained, instead of
`const File&`.

I was considering keeping a direct reference to the tree and tokens on
`Context`, but initially my thought was it wouldn't make much
difference. I can re-add those if desired, just as direct caching of the
`File` fields.
2024-12-06 21:17:24 +00:00
Richard Smith f8e7dad33a Include the file from which an entity was imported in formatted SemIR. (#4621) 2024-12-04 19:12:56 +00:00
josh11bandJosh L 5d1b39e1f2 More instructions get named (#4615)
Goal is to reduce churn in names in test updates (by churning a lot of
them in this PR).

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>
2024-12-03 20:47:53 +00:00
4ee65ef58a Reduce the size of formatted SemIR. (#4534)
- Do not include entities imported from files that we are not dumping.
- Do not include constants and import_refs that are not referenced by
something that we are including in the formatted output.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
2024-11-15 21:00:26 +00:00
Jon Ross-Perkins 10e256a241 Name empty tuples distinctly in SemIR. (#4503)
Building on #4502, give empty tuple values a distinct name, and also
explicitly name tuple types (previously values but not types were
named).
2024-11-08 17:14:52 +00:00
Jon Ross-Perkins d944347e7b Elide prelude components in the IR formatter. (#4453)
This is in particular to avoid churn from changes such as #4370. I think
the import list can be helpful (particularly to understand what the
library is aware of), but it's a different trade-off for the prelude
package due to the implicit imports.
2024-10-30 22:45:26 +00:00
Brymer MenesesandJon Ross-Perkins 89eed4220f Expose indexing as a language interface (#4370)
This PR makes it so that types can implement the `IndexWith` interface
so that they can provide their custom indexing behavior.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2024-10-29 21:25:02 +00:00
Geoff Romer b67d03126e Separate inst kind for out params (#4442) 2024-10-24 15:22:32 +00:00
Geoff Romer 9266f867f9 Model the return slot as an output parameter (#4432)
Also fix `Param` insts to have meaningful names in pretty-printing, to
help clarify relationship with return slot.
2024-10-23 16:53:34 +00:00
Geoff RomerandJon Ross-Perkins dc32aa2690 Initial support for binding patterns in SemIR (#4221)
Introduces the `BindingPattern` and `SymbolicBindingPattern` insts, and
a separate stack of pattern blocks that they are emitted into. The
intent is to generate the corresponding pattern-matching insts (like
`BindName`) from them in a separate pass, but that is deferred to future
PRs.

See
[here](https://docs.google.com/document/d/1U_vQH17V893J9aF1LJXUnFYBNSs2MjKl4bJPaWCB2zo/edit?usp=sharing&resourcekey=0-w0xGYZ0An31Kpz-wvzSXwQ)
for the design this is based on, but note that during review we have
chosen to deviate from that design by putting the patterns in separate
blocks, and omitting the "forward references" from a `BindingPattern` to
its corresponding `BindName`. This in turn necessitates having separate
inst kinds for symbolic and non-symbolic binding patterns.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2024-09-25 19:12:58 +00:00
Jon Ross-Perkins d4c7743d18 Update tests to use [[@TEST_NAME]] (#4293)
Applies #4278 TEST_NAME substitution to tests. Note I've tried to
structure commits as:

1. Do all the replacements.
2. autoupdate (nothing else) -- this shows incorrect updates.
3. Fix up manually, including autoupdates to get back to original
output.
2024-09-10 22:52:23 +00:00
Richard SmithandJon Ross-Perkins 187a3608df Use As and ImplicitAs interfaces for conversions. (#4209)
Add these interfaces to the core library. For now, they're two separate
interfaces because we don't yet support one interface extending another.

This collapses a lot of the layering in check: for example, the call
building logic depends on implicit conversions, conversions now depend
on the overloaded operator machinery, and that machinery depends on
building calls.

In passing, improve the diagnostics for failing to find a name required
from the prelude. Also convert all the transitively-called code from
`NodeId` to `LocId` given the latter is what the conversion machinery
has available.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2024-09-05 23:39:58 +00:00
Jon Ross-PerkinsandRichard Smith 7ded56ef35 Improve namespace handling in imports. (#4153)
This implements a few closely related features:

- Starts merging namespaces discovered inside imports.
- Stores results of cross-package name lookup as an entry inside the
scope.
  - Note this is particularly visible with `i32`.
- Moves more of the imported instructions to the import scope.

Note this is primarily for executing the namespace TODO in check.cpp,
which is removed here.
`testdata/namespace/merging_with_indirections.carbon` tests key
behavior.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2024-07-24 19:56:17 +00:00
Jon Ross-PerkinsandGeoff Romer 07c286e3cb Use the package/library name in ImportIRId formatting. (#4154)
Also adds import_ir_scope to namespace formatting. I'd done this as an
aid for #4153, and am splitting it out.

---------

Co-authored-by: Geoff Romer <gromer@google.com>
2024-07-22 22:43:36 +00:00
Jon Ross-Perkins 9581a1867d Move import refs to their own block. (#4103)
This executes on a TODO in AddImportRef to add instructions to their own
block instead of the File block. This has an important consequence of
removing a pattern from InstBlockStack that added to blocks not
currently at the top, cleaning up an issue for ArrayStack. The delta
here is then mostly in different formatting of the import refs, a
consequence of the separation.
2024-07-03 18:21:12 +00:00
Jon Ross-Perkins 5ebcbae2e8 Add a location to indirect imports. (#4098)
By adding an `ImportDecl` instruction, this creates something that can
be referenced through `ImportIRInst`.
packages/no_prelude/implicit_imports_entities.carbon is getting a test
of this (import_conflict and import_conflict_reverse).

Also re-packs ImportIR from 24 bytes to 16 on 64-bit, since I'm touching
everywhere that makes one anyways.
2024-07-03 17:34:39 +00:00
Richard Smith 1c07f959a8 Format types in SemIR using the formatting for their instruction. (#4035)
Don't use the pretty-printed type name, because that's intended for
diagnostics, not for a theoretically machine-readable format like SemIR.

Types are always constants, so omit the leading `constant.` on the type
instruction name.
2024-06-06 15:12:48 +00:00
Richard Smith 9a11e977b3 Improve formatting of the type of a function or generic class name. (#4033)
Don't format the *type of* the function `F` as `"F"`. Instead use
`"<type of F>"`.

Also improve instruction naming for function and generic class name
values: name the value after the function or generic class, and add a
`.type` suffix to the type.
2024-06-06 00:40:43 +00:00
Jon Ross-Perkins 83413479d7 Move some of the test information to TIP lines (#4007)
This has is a nice-to-have for me. Frequently I want to run a specific
test, and end up digging through output to be able to copy-paste the run
line. This uses TIP lines to inject the command into the file when using
AUTOUPDATE.

Note, one of the reasons I want this is because "bazel test
//toolchain/testing:file_test --test_output=all" has been regularly
exceeding bazel's output limit for me (workaround is either opening the
output file or specifying an obscure output limit flag), making it a
little harder for me to get the commands. However, frequently I'm adding
a file and want to iterate on it, so that's really the use case I have
in mind here.
2024-06-04 17:57:23 +00:00
Richard Smith 23f9065949 Implement proposal #3927. (#3963)
Change syntax for package declaration to put the `impl` keyword at the
start and remove the `api` keyword.

To support this, rearrange processing of package, library, and import
declarations to use the general modifier handling support in declaration
parsing rather than special-case logic.

There is an ambiguity in `impl package.Foo as Bar`, which we resolve by
treating `package` as an introducer after a modifier only if it's not
followed by `.`.
2024-05-21 00:36:03 +00:00
Jon Ross-Perkins 92fa0ac1ac Remove ImportRefUsed (#3934)
This was to track use of a declaration after import, prior to a
redeclaration. Per [discussion on
Discord](https://discord.com/channels/655572317891461132/1217182321933815820/1236016521059237962),
we likely don't need this check due to the change in behavior of
`extern`.

Rather than potentially getting one of many `extern` decls and depending
on it by accident, it is now planned to be _required_ to be imported,
and the library doing a non-`extern` decl must _know_ it's importing the
`extern` decl. The stricter requirement on the library means it now
seems more reasonable to use the `extern` decl.

So kind of rolling back #3831, though keeping `ImportIRInstId` (at least
for now) and keeping `Loaded`/`Unloaded` terminology (seems a nicer
fit).
2024-05-03 23:33:42 +00:00
Jon Ross-PerkinsandRichard Smith 76ed3c73cb Promote FunctionType to a standard instruction. (#3931)
This removes the builtin FunctionType, replacing it with a FunctionType
instruction. The constant for a FunctionDecl is now a StructValue with
type of FunctionType.

Note this means a function declaration produces _both_ a type, and a
value of the type. This has some consequences in terms of circularity,
and makes the importing of function declarations a little more complex.

It'll get particularly peculiar for imports because of the behavior of
the reference, but that's a known issue due to other things such as
`alias`. The impact will hopefully be contained to
ResolvePrevInstForMerge (and ImportRefs).

To note a small formatting change in diagnostics:

```
-  // CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated <function> in Interface>` is not callable.
+  // CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated F in Interface>` is not callable.

-  // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated <function> in Interface>` is not callable.
+  // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated F in Interface>` is not callable.
```

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2024-05-03 15:18:04 +00:00
Richard SmithandJon Ross-Perkins 62fe0cd385 Remove the builtin IR, and instead define builtin types locally. (#3910)
We don't need it any more, and removing it simplifies a few things:

- One fewer predefined `File` and reserved ID.
- We now have simply `Builtin` instructions for builtins, instead of
having an `ImportRef` that indirectly references a `Builtin`.
- `ConstantId`s now always refer directly to a local constant, instead
of sometimes referring to an `ImportRef` for a constant in the builtins
IR.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2024-04-24 18:32:59 +00:00
Richard Smith 3776c068de Unify instruction naming between SemIR and LLVM IR (#3898)
Factor out `SemIR::InstNamer` and also use it when lowering to LLVM IR.
Automatically name all instructions created with our `IRBuilder` based
on the name computed by the `InstNamer`, and likewise name basic blocks
using the label generated by the `InstNamer`.

Move some of the existing naming logic out from lower into `InstNamer`
so that it's also used in SemIR. In particular, we now name call
instructions after their callee, or after the builtin name for calls to
builtins.

Computing and adding these names isn't completely free. This instruction
naming is designed to be optional, so that we can turn it off for builds
where the LLVM IR will only be converted to assembly and won't be seen
by a human, but so far it's enabled unconditionally. We can tune that
later as needed.
2024-04-19 02:19:30 +00:00
Richard Smith 015c7c780c Fix location of converted inst for explicit as conversion. (#3887)
Use the complete location of the `as` conversion rather than the
location of the first operand, so diagnostics referring to the result
point at the whole thing.
2024-04-15 23:22:44 +00:00
Richard Smith 1b335402d1 Allow incomplete return types in function declarations. (#3875)
Move completeness check to the point where the function is defined or
first called. This means we also defer deciding whether the function has
a return slot until that point. Instead of storing a return slot per
function, store the location of the return storage, which may or may not
be used, and compute and store a separate flag saying whether to use it
at the point of first use or definition.

This is the final piece in supporting simple `Make` functions in classes
as a replacement for constructors.
2024-04-11 07:23:56 +00:00
Jon Ross-Perkins 895e90e791 Start including the prelude for testing. (#3861)
- Adds an empty prelude.carbon file
- Imports that file in any non-Core package file
  - Adds --disable-prelude-import to avoid that
- Adds --exclude-dump-file-prefix to be able to hide files from dumping
- Used to hide core files (we can't do this by package name due to lex
dumps, for example)
- Restructures some tests to not rely on `i32`, particularly `alias`
tests (which rely on a name ref) and tests with no prelude.

I'm adding the framework for switching i32 to calling Int32 in the
prelude, but I'm running into a separate error actually switching over.
So that *mostly* works, but isn't quite ready for prime time. However,
maybe the current state of this PR is still useful to review since it
does a lot of the infrastructure work and adds the %Core everywhere?
2024-04-07 17:11:42 +00:00
Jon Ross-Perkins 6889aff49a Add functions for instantiating builtin types through lookup. (#3857)
Note, my instinct is that `Float(dyn_size)` should be invalid. However,
I think the constant evaluation doesn't result in the call being
evaluated in eval.cpp when the size is non-constant. I think I could get
an error for symbolic phase calls, but that seems a little less
interesting already. Long-term maybe we want a way to mark functions as
_must_ be evaluated during constant phase?

Also, I think there may be a bug with literal value parse node
locations, I should be able to point at the position of `arg_ids[0]` but
it's missing a line number so I point at `loc` instead.
2024-04-04 23:47:06 +00:00