Commit Graph
225 Commits
Author SHA1 Message Date
Jon Ross-Perkins 27d0d26739 Replace value_kind with has_type, make FormatInstLhs name-dependent (#5501)
InstValueKind is really just wrapping HasTypeIdMember. Rather than
exposing this as an enum, expose it as a bool since it better reflects
what's going on.

In eval.cpp, AddImportedConstant should never be called on an untyped
instruction.

In FormatInstLhs, we can also depend on whether InstNamer has assigned a
name in order to decide whether to print an instruction. This should
avoid some divergence with CollectNamesInBlock.

We also discussed restoring InstValueKind::Untyped, but that's mainly
motivated by the formatter, and the InstNamer approach gives a more
localized implementation.
2025-05-19 23:26:32 +00:00
Jon Ross-Perkins fbaae723bc Collapse identical overloads of FormatInstLhs (#5495)
This is code sharing, but also removes some emphasize on templated call
structure.
2025-05-19 21:19:17 +00:00
Jon Ross-Perkins e78a57bb82 Adjust formatting of blocks and scopes (#5474)
This is making two inter-related changes:

- Change `file` to reuse the formatter logic of `constants` and
`imports`, meaning empty `file` scopes will be omitted
- Mark `<elided>` sections in blocks (not in non-block scopes, because
they're not as sequential)
2025-05-16 22:50:28 +00:00
Jon Ross-Perkins cc416171e2 Have FormatScopeIfUsed consider ranges before printing (#5454)
If there will be no in-scope instructions printed, have
`FormatScopeIfUsed` skip the relevant scope.

Note, this only affects constants and imports. It's not changing the
file scope, which is usually printed when empty.
2025-05-12 15:55:03 +00:00
Jon Ross-Perkins 937caaecce Add --dump-sem-ir-ranges for controlling dump output (#5450)
Right now, a lot of tests have started setting `--no-dump-sem-ir`. My
thought is that we can look at:

1. Put ranges in a bunch more files.
2. Shift more towards `--dump-sem-ir-ranges=only` instead of
`--no-dump-sem-ir`, because it allows mixing fail-tests with no IR
alongside tests that contain IR.
3. Evaluate switching the default to `--dump-sem-ir-ranges=only`, and
instead set `--dump-sem-ir-ranges=if-present` only in files that want to
typically show all IR (particularly import-related tests, where ranges
don't work well).

In real-world use, my thought is also that it'd be helpful to be able to
add the dump range comments to files, see the output (i.e., the default
behavior of `if-present`) but then also be able to pass `ignore` in
order to see the full IR without modifying the file (possibly also
useful in tests). That model is why I went for tri-state handling.

Note `only` can also have an interesting side-effect. Because core files
(including min_prelude versions) typically won't have ranges, they'd be
implicitly excluded.
2025-05-12 14:51:10 +00:00
Jon Ross-Perkins 0683742f19 Cache multi-IR info, particularly include_in_dumps (#5408)
Right now we construct `tree_and_subtrees_getters` a couple different
ways, it's just not obvious because one's abstracted in `check`. But
also, when formatting IR, we'll repeatedly do the `IncludeInDumps`
string check, which felt odd to me since it only needs to be calculated
once per IR.

This also shifts `CheckIRId` selection a little earlier, and in doing so
makes `CheckParseTrees` accept a sparse `units` argument. I actually
think this is a positive: it makes `CheckIRId` a little more stable
across possible command lines, when file loading fails (which is the
only time that a file will have a `CompilationUnit` but not a
`Check::Unit`).

Trying to build on the shared issue between these, I'm adding a
`MultiUnitCache` to store the calculated arrays. For the subtree
getters, this is very minor and avoids at most one incremental array
construction (moving logic out of `CompileSubcommand::Run` might be the
bigger benefit). For `include_in_dumps`, when dumping SemIR, this is
changing a calculation run once per entity (in each IR) to be calculated
once per IR (globally), i.e. O(M*N) -> O(N).

Note this seems to be marginal for performance of file_test:

- Before: Stats over 10 runs: max = 5.3s, min = 4.7s, avg = 4.9s, dev =
0.2s
- After: Stats over 10 runs: max = 4.9s, min = 4.7s, avg = 4.8s, dev =
0.1s

I was mainly thinking about this in the context of dumping SemIR ranges.
There, the impact may actually decrease because a range won't do any
cross-IR printing. But, I'm expecting to add another layer for whether
we're printing IR for a file, and that made the `should_format_entity`
callback stick out for me.
2025-05-02 22:53:46 +00:00
Jon Ross-Perkins 1f268b5d8b Consolidate token-related range handling to one struct (#5399)
This consolidates Lex::TokenizedBuffer::DumpSemIRRange and
Parse::TreeAndSubtrees::TokenRange into a single InclusiveTokenRange,
also making the OverlapsWithDumpSemIRRange function take the new struct.

I considered switching to `llvm::iterator_range<Lex::TokenIterator>`,
but we often want to see if the range is size one. Using `TokenIterator`
just looked like it'd add a bunch of offsetting to make it work; I view
that as low-value overhead.

For example:

```
  Lex::InclusiveTokenRange token_range = GetSubtreeTokenRange(node_id);
  auto begin_loc = tree_->tokens().TokenToDiagnosticLoc(token_range.begin);
  if (token_range.begin == token_range.end) {
    return begin_loc;
  }
  auto end_loc = tree_->tokens().TokenToDiagnosticLoc(token_range.end);
```

would become:

```
  llvm::iterator_range<Lex::TokenIterator> token_range = GetSubtreeTokenRange(node_id);
  auto begin_loc = tree_->tokens().TokenToDiagnosticLoc(*token_range.begin());
  if (token_range.begin() + 1 == token_range.end()) {
    return begin_loc;
  }
  auto end_loc = tree_->tokens().TokenToDiagnosticLoc(*(token_range.end() - 1));
```

So I'm keeping the bespoke struct.
2025-05-02 18:47:02 +00:00
Jon Ross-Perkins 6469f67b14 Switch to a constant-time approach for dump ranges, tracking node parents (#5394)
- Adds parent information as a single-pass calculation
  - Moves off `GetSubtreeTokenRange` because it's O(N)
- Stops using the node's subtree when formatting a single instruction
- This excludes `%F.call` and the following `return`, for example,
because only parameters are marked for formatting
2025-05-02 17:01:10 +00:00
Richard SmithandDana Jansens 4f5d11a28b Build generic eval blocks incrementally (#5313)
Instead of building an eval block as a separate pass at the end of a
generic, build the eval block incrementally.

The larger change here is that asking for the type or constant value of
an instruction now always returns an unattached type or constant value,
in order to preserve the behavior that we previously achieved by doing
the rewrite to attached types and constant values at the end of handling
the generic.

This also incidentally fixes some subtle issues where attached types and
constant values would leak out into check and cause it to get confused
about differences between attached and unattached values. Check should
no longer see attached values except where it explicitly asks for them.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-05-01 20:24:15 +00:00
Richard Smith 797b14eb8e Import ImplWitnessTable into the imports block instead of the constants block. (#5374)
Don't import `ImplWitnessTable` into the `constants` block, because we
generally don't put `Unique` constants there. This matches the handling
of the other kinds of `Unique` constants. In order to keep the
instruction visible in formatted SemIR, add it to the `imports` block
instead.

Also fix a bug in the instruction formatter that resulted in
instructions in the `imports` block being omitted from the output if
they were only referenced by earlier instructions in the `imports` block
and by instructions in the `constants` block. This was already resulting
in some referenced instructions being omitted from the output, but also
occurred frequently for `impl_witness_table` instructions after this
change because it is common for the only reference to those instructions
to be from `impl_witness` instructions in the `constants` block.
2025-05-01 00:08:43 +00:00
Richard Smith 5226f3d14a Factor out GetInstWithConstantValue and use it from another place that duplicates the same logic. (#5388) 2025-04-29 23:28:46 +00:00
Jon Ross-Perkins 8eae40646a Add formatter support for dump-sem-ir ranges (#5379)
This prints instructions that are inside the range, and entities that
overlap with the range. Note this can lead to incomplete printing of
entity contents.
2025-04-29 22:18:52 +00:00
Jon Ross-PerkinsandDana Jansens 5da87f43da Split SemIR's formatter class into a more typical h+cpp (#5372)
Trying to make it easier to see the API at a glance. The class has
become really long, and this doesn't fundamentally change that, but
hopefully makes it easier to navigate. The entry structure also had some
cruft that I'm removing.

I'm trying to keep functions in the same order as they currently are.
The delta still looks unhappy because of the churn, but hopefully this
at least explains the ordering in formatter.h. You can try using the
"Add indent" commit on the PR to see a better before-after delta.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-04-29 18:00:07 +00:00
Dana JansensandJon Ross-Perkins 315e206ff1 Construct LocId from InstId directly (explicitly) instead of doing lookups when possible (#5355)
Remove calls to `InstStore::GetLocId()` to build a LocId from an InstId
now that they can be constructed directly from the InstId. Most uses of
LocId are just plumbing, so this does not affect them. However places
that want to look inside the LocId do not want to work with the InstId
form. In these places, introduce `InstStore::GetResolvedLocId()` which
converts a LocId (or an InstId as an optimization) into a LocId which is
not backed by an InstId. These locations can be printed (they have a
line and column when they are a NodeId), they can have flags added to
them (`ToImplicit`, `ToTokenOnly`), they can be converted to an
underlying ImportIRInstId, or they may be `None`.

`Dump()` is made to print a resolved location instead of printing the
InstId in the location, since (at least in my experience) the resolved
location is what is interesting in debugging, and this saves manual
`MakeInstId` steps in the debugger every time a location is of interest.

The LocId constructor from InstId is made `explicit` to add clarity to
function calls passing an `inst_id` now directly instead of calling
`context.insts().GetLocId(inst_id)`. To avoid needing to construct
`SemIR::LocId(...)` explicitly in all cases though, the diagnostics code
in Check uses `DiagnosticLocId` as its template parameter which accepts
InstId as well and does the construction of LocId from it.

Because LocId now requires an explicit construction from InstId, any
callers to `AddInst()` functions will have to explicitly convert to
LocId if they had an InstId, but not if they pass a NodeId. To make this
difference clear to callers, we `requires` that the input type can be
converted to LocId. This ensures that passing an InstId results in an
error at the callsite where the InstId is passed, instead of generating
a compiler error when trying to construct `LocIdAndInst` inside
`AddInst()`, which is less clear about what went wrong and doesn't seem
entirely intentional.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-04-28 19:06:24 +00:00
Jon Ross-PerkinsandRichard Smith 949cc21ccc Remove SemIR:: from most sem_ir files (#5358)
This is just cleanup, at least some from LocId replacements.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-04-25 16:06:10 +00:00
Boaz Brickner 609ccefd18 Introduce a Clang diagnostic instruction and use it to point to C++ source locations on Clang errors and warnings (#5262)
Introduce `ImportIRId::Cpp` and refer to clang source location in its
`ImportIRInst`.

Part of #5245.
2025-04-25 13:05:45 +00:00
Richard Smith ca8df34d0d Format the call parameters of a function, not the patterns. (#5342)
This makes the parameters printed in a SemIR `fn` declaration match the
arguments printed in a SemIR `call` instruction.
2025-04-22 18:52:21 +00:00
Thomas Köppe bf32da8dad Add missing standard library header inclusions (#5316)
Discovered by clang-tidy.
2025-04-17 15:37:57 +00:00
Dana JansensandRichard Smith 0e8d354567 Split the witness table into a separate ImplWitnessTable instruction (#5272)
This allows us to import the table for a given impl only once, while we
can import many ImplWitness instructions with different specifics for a
generic impl.

For example in convert_facet_value_to_narrowed_facet_type.carbon we see
that a single witness table is imported for the BitAnd interface, with
multiple witnesses (for different specifics) imported and sharing the
same table.

The ImplWitnessTable now contains a back-link to the Impl the witness is
for, allowing inst namer to name that interface in the textual semir,
and allowing the interface to be found when debugging from a witness.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-04-11 20:30:04 +00:00
Jon Ross-Perkins fe29224016 Refactor LocId to merge in SemIRLoc (#5284)
The main goal of this is to collapse the LocId and SemIRLoc types into a
single type, eliminating the need for APIs to decide which to use. This
originated from discussion about UnwrapSemIRLoc in #5169. Although that
was removed in #5202, it's probably still a good direction for LocId.

This changes the packing of LocId to allow adding InstId, making it
tri-modal: ImportIRInstId, InstId, or NodeId. This has a side-effect of
reducing the available space for ImportIRInstId, although not by much
due to the pre-existing `ImplicitBit` behavior. If needed, we could also
probably play with packing a bit more since `ImplicitBit` really only
applies to `NodeId`, but I was trying to keep the logic a little
simpler. Note `TokenOnlyBit` can still apply to `ImportIRInstId`.

This leaves in place a typedef for SemIRLoc -- I intend to clean that up
separately.

Some Discord discussion is
[here](https://discord.com/channels/655572317891461132/655578254970716160/1353755830058745959).
2025-04-11 13:35:58 +00:00
Dana JansensandRichard Smith cf57c85545 Introduce TypeInstId (#5288)
TypeInstId is an InstId whose constant value has a type of TypeType.
This includes:
- Type value instructions, the `ClassType` or `IntLiteralType`
instructions.
- Constraint value instructions, which are the `FacetType` and
`TypeType` instructions, each of which also have type TypeType.

TypeInstId encodes in the type system that it is safe to convert the
instruction's value to a TypeId, and CHECKs at construction that this
invariant is maintained.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-04-10 22:59:02 +00:00
Richard Smith a74ca9071b Remove all remaining uses of TypeIds as instruction operands. (#5280)
In preparation for shifting from `TypeId`s potentially representing
attached types to always representing unattached types, using
[terminology suggested on
Discord](https://discord.com/channels/655572317891461132/963846118964350976/1359286326779973712).
This change causes us to track slightly more type spelling information
through SemIR.

One change that has significant impact on the SemIR output is that we
now build a `struct_type` instruction in each class representing the
types of the fields, including the spelling used for those types. This
is now no longer always identical to the corresponding canonical
`struct_type` for the object representation, so it's built separately
and owned by the class.

Also remove `TypeBlock` support entirely, as its only use was
representing `TupleType`s, which now use an `InstBlock`.
2025-04-10 20:53:42 +00:00
Richard Smith a91752de60 Represent rewrite constraints in FacetTypeInfo with InstId not ConstantId. (#5281)
This follows the pattern used elsewhere, and allows facet types in eval
blocks to directly reference their operands instead of doing so
indirectly via a `ConstantId` attached to the generic. This prepares us
for making `ConstantId`s always be unattached.

In passing, add a stringified version of the `InstId` to diagnostics in
a couple of places where it seems useful.
2025-04-10 03:56:12 +00:00
4af0c8f8d1 Implement ...where .Self impls... (#5238)
* Also remove facet type deduction, since we decided against it on
[2025-04-02](https://docs.google.com/document/d/1Iut5f2TQBrtBNIduF4vJYOKfw7MbS8xH_J01_Q4e6Rk/edit?pli=1&resourcekey=0-mc_vh5UzrzXfU4kO-3tOjA&tab=t.0#heading=h.95phmuvxog9n).

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-04-07 20:45:45 +00:00
David Blaikie 4739828cca Generalize non-const ClassInit lowering beyond only InitializeFrom insts (#5199)
Fixes #5186

With @zygoloid's kind assistance, this generalizes the existing
non-const lowering of ClassInit, that had previously only handled
InitializeFrom, to find other cases - such as a nested ClassInit used to
initialize a class member.

This refactors the `FindReturnSlotArgForInitializer` from
`check/convert.cpp` into `sem_ir/file.{h,cpp}` for use from lowering
(since lower doesn't depend on check, which I assume is an intentional
layering constraint - so figured it made sense to move it to sem_ir, and
found one or two similar-ish utility functions in `sem_ir/file.{h,cpp}`,
so figured that was a good spot)
2025-04-01 18:45:07 +00:00
josh11bandJosh L c7a338be59 Replace uses of "defined" with "complete" (#5196)
As of #5087, these terms are no longer synonyms. This change preserves
the original meaning.

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>
2025-03-27 18:14:26 +00:00
Dana JansensandJon Ross-Perkins 53c98a8619 Support specialization in impl lookup with a symbolic query/impl. (#5169)
Add a new instruction called ImplSymbolicWitness which represents a
search for an impl declaration given a self type and an interface to
find implemented for the self type. The self type is stored as a
constant instruction id, rather than as a ConstantId, as instructions
don't currently support holding ConstantId. The interface is stored as a
SpecificInterface but we can't fit all of it directly into the
instruction. So we add a new id to refer to the SpecificInterface as
follows.

Add a new SpecificInterfaceId which indexes into a canonical value store
on SemIR::File. This tracks all `SpecificInterface`s stored in an
instruction - specifically the ImplSymbolicWitness instruction.

The SpecificInterface on Impl is still stored there as a value, not as
an id, and no id is eagerly constructed for it. We wait until an id is
needed to make one. Since they are canonical, a new id is only create
when a new SpecificInterface value is seen.

When doing impl lookup, and the query is not concrete, and the impl is
not effectively final, the query needs to consider future impls that may
specialize either the self type or the constaint to make a more precise
match and replace the found impl declaration. Instead of returning the
ImplWitness instruction from the found impl, we generate a
ImplSymbolicWitness instruction, storing the query so that it can be
replayed later. This instruction is added to the generic eval block and
thus will be re-evaluated later with a SpecificId that may make the
query more concrete. When evaluating the instruction and replaying the
query, the lookup has the same conditions and if it does not decide to
use the found impl concretely, then the same instruction is returned
from eval, leaving it as symbolic.

--- Impl lookup changes ---

Impl lookup gets a little more interesting now. It continues to look in
the facet value for a witness if the self type is a facet value. Then
falls back to looking for an impl declaration. This step is no longer
done directly. Instead, we construct a ImplSymbolicWitness instruction
and evaluate it immediately for each interface that are in the query
facet type.

The ImplSymbolicWitness instruction, when evaluated, calls back to the
impl lookup code, with a query specific interface. There we resume back
into the same code path as from before, finding a witness in an impl
declaration. But we may return "found a non-final impl" instead of a
concrete witness. If eval receives this back, it evaluates to the
current ImplSymbolicWitness instruction as the resulting constant value.

To pass lookup failures back through eval, a result of InstId::None from
the second step of impl lookup will result in a non-constant value,
which is used as a signal back up the stack to the original impl lookup
function that the lookup failed. Using a non-constant value here would
break evaluation of the generic eval block if impl lookup could fail
there, however we know it will not since we only leave behind an
ImplSymbolicWitness instruction in the eval block if we found at least
one matching impl already, and we just want to look for a better match
with a more specific query.

We must take care to not store a reference into any value store across
computation in impl lookup, since impl lookup can recurse into itself
invalidate those stores. That includes the SpecificInterface obtained
from a SpecificInterfaceId, which impl lookup also inserts into the
store.

--- The long tail ---

Adding a new instruction and a new id type requires a myriad of changes
to support them:

We add Dump() support for SpecificInterfaceId. And fix a crash in Dump
for SpecificId::None. We also add MakeSpecificInterfaceId() for dumping
arbitrary ids.

The type of ImplSymbolicWitness is a new singleton builtin type
instruction called WitnessSymbolicType (like WitnessType is the type for
an ImplWitness).

Both ImplSymbolicWitness and WitnessSymbolicType are given `Value` as
their expression category as they are builtin constant values. And
BuildInfo() in TypeCompleter is taught about them both, returning a
`ValueRepr::Copy`.

WitnessSymbolicType is added to the set of SingletonInstKinds, so that
it can have a singleton instrution id as a static member.

Lower's BuildTypeForInst() is taught to make an empty struct for
WitnessSymbolicType, similar to WitnessType.

Instruction formatter (FormatterImpl) grows support for printing a
SpecificInterfaceId so that it can print both arguments of
ImplSymbolicWitness on the RHS when printing the SemIR instruction. To
print a SpecificInterfaceId, it prints both the interface id and the
specific id (if there is one). For example, for a query on a generic
interface `Z` with one parameter, the RHS includes the query, interface,
and specific:
```
%Z.impl_symbolic_witness: <symbolic witness> = impl_symbolic_witness %U, @Z, @Z(%U.as_type) [symbolic]
```

IdKind is extended to include SpecificInterfaceId.

InstFingerprinter is taught to look through SpecificInterfaceId and use
the interface and specific ids in the fingerprint.

InstNamer is taught about SpecificInterfaceId, counting the interfaces
when building an index. It is also tought about ImplSymbolicWitness,
using the name of the interface within and the `.impl_symbolic_witness`
suffix. For example, here the LHS is named after the interface in the
query:
```
%Z.impl_symbolic_witness: <symbolic witness> = impl_symbolic_witness %U, @Z, @Z(%U.as_type) [symbolic]
```

StringifyTypeExpr is taught about WitnessSymbolicType, which uses its IR
name since it's a singleton. And about ImplSymbolicWitness which uses
its constant value. The handling of ImplWitnessAccess also needed to be
adjusted, since it assumed that ImplWitnessAccess::witness_id would
always be a FacetAccessWitness, but it can now also be an
ImplSymbolicWitness. (It seems that the witness_id is also assigned
ImplWitness instructions, but those ImplWitnessAccess instructions don't
ever seem to get stringified in a diagnostic at this time.) At the
moment the ImplWitnessAccess with a symbolic witness is just stringified
as "<symbolic>", such as in:
```
x.carbon:1:2: error: cannot implicitly convert value of type `()` to `<symbolic>` [ConversionFailure]
  let a: C(D).(Z.X) = ();
                      ^~
```

There is a TODO left behind to include more information there.

The TypeStructure builder is made to handle WitnessSymbolicType and
WitnessType. These come up now in deduce where a generic impl will have
a ImplSymbolicWitness in a FacetValue for a generic self type. The query
may have a concrete ImplWitness in the same position. Since deduce tries
to deduce through the FacetValue, it tries to convert ImplWitness to
ImplSymbolicWitness, tries to do an impl lookup for `impl ImplWitness as
ImplicitAs(ImplSymbolicWitness)` and causes us to build type structures
with each of these.

Subst is updated to handle pushing and popping SpecificInterfaceId.
Without this, when finishing a generic's eval block, we would walk into
the ImplSymbolicWitness instruction, and its arguments, and fail to
recurse down into the SpecificInterfaceId. Then any specifics inside
would be left as "orphaned" without any generic id attached to them, and
we would never update the instructions in the SpecificInterface's
instructions (inside its own SpecificId) with new constant values when
evaluating the generic eval block against a specific. To do this we push
the specific_id inside the SpecificInterface, and when popping we pop
the specific_id then construct a new canonical SpecificInterface with it
and return that id.

We add support for importing ImplSymbolicWitness by importing its self
constant instruction and specific interface id. However we also had to
add import support for SpecificImplFunction, which can now appear in the
generic eval block for a generic impl declaration, and thus must be
imported with the declaration. This is done very similarly to
SpecificFunction, except the `type_id` is a singleton value.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-03-26 15:10:23 +00:00
Richard Smith 584426dfa2 Initial work on support for templates (#5081)
This broadly follows the design described in [this design
document](https://docs.google.com/document/d/1eWW8MTko3PIqxZ32-GhsdaRSYqoDicxMB1VeessMTOg/edit?pli=1&tab=t.0).

Support is provided for only two primitives for now -- simple member
access and type conversion -- to demonstrate the basics of the
functionality.
2025-03-19 20:19:21 +00:00
Geoff RomerandJon Ross-Perkins a584ee120e Add support for _ binding patterns (#5097)
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-03-17 22:29:56 +00:00
Boaz Brickner fcd38a4d7f Add support for importing C++ namespaces (#5103)
This adds support for having different C++ `NameScope`s (and not just
the main `Cpp` scope), and we keep a pointer to `clang::DeclContext`
these scopes so we can look up C++ names in the right part of the AST.

C++ Interop Demo with a namespace:

```c++
// hello_world.h

namespace some_namespace {

void hello_world();

}  // namespace some_namespace
```

```c++
// hello_world.cpp

#include <cstdio>

namespace some_namespace {

void hello_world() { printf("Hello World!\n"); }

}  // namespace some_namespace
```

```carbon
// main.carbon

library "Main";

import Cpp library "hello_world.h";

fn Run() -> i32 {
  Cpp.some_namespace.hello_world();
  return 0;
}
```

```shell
$ clang -c hello_world.cpp
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link hello_world.o main.o --output=demo
$ ./demo
Hello World!
```

Closes #5102
2025-03-15 20:41:48 +00:00
Geoff RomerandRichard Smith 6d4f2567a7 Add support for var patterns (#5069)
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-03-06 19:06:51 +00:00
Geoff Romer d264f14027 Clean up handling of Call params (#5061)
- Explicitly document that `*Param` and `*ParamPattern` insts represent
`Call` parameters.
- Stop wrapping compile-time parameter patterns in `ValueParamPattern`
insts (because they aren't `Call` parameters).
- Document how `MatchContext::results_` relates to the `Call`
parameters, and be more consistent about when it's written to.
- Remove `RuntimeParamIndex::Unknown`: we no longer need to distinguish
"this `Param`'s runtime index is unknown" from "this `Param` isn't a
runtime param", because we no longer use `Param`s at all in the latter
case.
- Rename `RuntimeParamIndex` to `CallParamIndex`.

As a side effect of removing the `ValueParamPattern` insts, this fixes a
minor diagnostic bug where `NoteInitializingParam` didn't identify the
specific parameter that led to a deduction failure, because it expects
generic parameters to only be represented by `SymbolicBindingPattern`s,
but before this change they could be wrapped in `ValueParamPattern`s.
2025-03-04 21:01:59 +00:00
Jon Ross-PerkinsandDana Jansens 467e510d40 Document abbreviation style things (#4996)
We had a long discussion of this, so trying to document what seems to be
the conclusion... and also clean up the exceptions that I could find.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-02-27 02:13:17 +00:00
Richard Smith 0d2f364f39 Split evaluation up into one function per instruction kind (#5008)
Replace the large and growing `TryEvalInstInContext` function with one
function per kind. While we still have special-case handling for a small
number of instruction kinds, most instructions are now handled either
fully automatically or use a common codepath that evaluates the
instruction operands and then performs an eval-context-independent
evaluation of the instruction.

To support this, `InstConstantKind` is expanded to describe more
fine-grained details about how each kind of instruction interacts with
constant evaluation. Also, the operand kinds of instructions become
slightly more fine-grained: we now distinguish between operands that
describe the destination of an initializing expression (`DestInstId`)
from other `InstId` operands, because `DestInstId` operands need
different treatment during constant evaluation. In particular, an
initializing expression can have a constant value even if its
destination is non-constant or has not yet been set, because evaluation
of an initializing expression doesn't include the store to the
destination.

Some minor test changes:

- We now more consistently propagate errors into the results of constant
evaluation, so more instructions that depend on errors have a constant
value of `<error>`.
- Diagnostic location for invalid array types now point at the whole
array type rather than the array index expression, because
`EvalConstantinst` doesn't have access to the original expression.
- Diagnostic for failed `RequireCompleteType` doesn't print the original
type any more because `EvalConstantInst` doesn't have access to the
original expression.

As a follow-up, some of this -- in particular, the `EvalConstantInst`
overloads -- will be moved to a separate file, in an effort to split the
overall constant evaluation machinery apart from the logic to evaluate
each individual kind of instruction.
2025-02-27 01:31:26 +00:00
Dana JansensandRichard Smith 11aba70c1d Add enumerate() for ValueStore and ImplStore (#4975)
This allows iterating on all values in a store along with the Id for
each value, instead of `llvm::enumerate(store.array_ref())` which would
give you the indices.

While the indices are really the same as the Ids, this provides a
typesafe way to enumerate() over a store.

There's no use for this right now, but I thought I needed this, and it
helped me debug, and it was a pain to write correctly without dangling
references.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-02-19 18:32:13 +00:00
Richard Smith e0b2f5d772 Add and propagate template phase for constants. (#4964)
Treat template bindings as introducing template phase, and propagate it
in the same way we propagate the checked generic phase.

Rename "symbolic" to "checked symbolic" to make room for "template
symbolic". Also rename "phase" to "dependence".
2025-02-18 18:57:34 +00:00
Boaz Brickner 986a2a064c Add poisoned names to the format (#4961)
Part of #4622.
2025-02-14 19:18:51 +00:00
Richard Smith 6dda094928 Superficial support for template modifier on symbolic bindings. (#4948)
Change parse tree from `template (T:! type)` to `(template T):! type`,
so that we have information about whether a binding is a template
binding available when forming the representation of the binding
pattern. This incidentally fixes a bug that we would accept `template
addr A:! B` instead of the intended `addr template A:! B`.

Track whether a symbolic binding is a template binding on the
`EntityName` object. I'm borrowing a bit from the `CompileTimeBindIndex`
for this in order to avoid making `EntityName`s larger. Longer-term, we
should think about using a different representation for symbolic
bindings, to avoid including these fields in all `EntityName`s, but
that's out of scope for this change.

So far, template bindings are treated as having the same phase as
checked bindings, but that will change in a future PR.
2025-02-13 02:15:22 +00:00
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
Boaz Brickner 3f599c250b Generate Cpp namespace when import Cpp is used (#4873)
Also defined a dedicated `ImportCppDecl` `InstKind`.
Part of #4666
2025-02-12 01:44:37 +00:00
Richard SmithandJon Ross-Perkins 8eb4e24cb6 Implement #4864: Core is a keyword (#4909)
Change representation of package names from `IdentifierId` to
`PackageNameId`, and add a special value `PackageNameId::Core` for the
Core package. Add a `Core` expression to name the Core package, and
support for parsing the `Core` keyword in `package` and `import`
declarations.

For now, I've made no changes to instruction fingerprinting or name
mangling. This means that fingerprints and mangled names will collide
between names in the `Core` package and names in a `r#Core` package. See
#4908.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-02-11 21:33:57 +00:00
Boaz Brickner 3d39ab67bf Wrap lookup result in a new ScopeLookupResult (#4831)
Benefits:
* Provide a proper API for accessing lookup information.
* Make assumptions on whether the result is poisoned or not and how we
can use `InstId` explicit.
* Allow safely reusing the `InstId` value for pointing to the poisoning
entity for poisoned results (in a future PR).
* Consolidate `LookupNameInExactScopeResult`, `std::pair<SemIR::InstId,
bool>` and part of `LookupResult`.
Part of #4622.
2025-01-27 10:05:23 +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 b06fcc97f6 Clean up a few details of lex yaml printing (#4845)
- Escape dumped token strings (what got me here)
- Change the quoting from backticks to quotes
- Also add a `FormatEscaped` helper function for this, updating other
`.write_escaped` uses
2025-01-24 21:52:02 +00:00
Jon Ross-Perkins 9c0faf007e Invalid comment cleanup (#4836)
This is a followup from #4834, I searched for "invalid" uses in our
codebase. This is mostly changing comments, and a couple debug
functions, but shouldn't affect testable behavior.

Note a couple things I'll highlight as not changing (but could) are:
- `ReturnTypeInfo::is_valid`
- `"invalid"` uses in the formatter
- `AddInvalid` for `!has_value` in `inst_fingerprinter` (because the
cases it's called sound invalid-ish)
2025-01-23 02:21:48 +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
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