Commit Graph
22 Commits
Author SHA1 Message Date
Chandler Carruth d0badecd2a Switch tests to use the rendered form of diagnostics (#8070)
Historically, we disabled the rendered form in tests outside of
`toolchain/diagnostics`. The idea was to keep tests shorter and avoid
very long chains of autoupdate before stabilizing due to all the line
numbers and other artifacts in the rendered form.

This PR adds `--diagnostic-line-numbers=[all|first]` and defaults to
`first` in tests. This keeps the rendered form so that we can easily
code review that form and the visual cues it does or doesn't provide.
But it removes all but the first location's line numbers to provide
significantly more stability in tests.

By default, tests get the full unicode line-drawing form of diagnostics
so we can ensure all of the artifacts there make sense with the specific
case being diagnosed, but we do retain some focused ASCII-rendering
tests to ensure that fallback remains usable.

There are some issues here that will be fixed in subsequent PRs.
Notably, we try to keep the frame together in the check lines, and so
force some parts to use the first location. This largely works, but
fails in some edge cases, causing the entire frame to be located
incorrectly. There is a TODO about this that we need to fix, and it only
occurs 6 times across the test suite, so it didn't seem worth
front-loading a fix for here.

Assisted-by: Claude Code
2026-11-05 07:19:59 +00:00
Chandler Carruth c608c35e12 Rework the initial terminal rendering into the form the design landed on (#7994)
There were a number of iterations on the design that weren't reflected
in the initial port to the terminal rendering library. This PR tries to
complete the rendering side of things to match the design we landed on:
code-focused, with messages attached by lines to the code, and condensed
as much as possible to avoid the vertical space.

It also improves the styling to make things more visually
distinguishable such as adding a `->` to the main error line, and making
the underlines and connectors for it have a heavy weight (when the font
supports that).

Another major change is having multiple messages on a single line be
drawn in source lexical order. This requires the connectors to cross
without joining, but makes it easier to read the messages.

This PR also has some refactorings to enable these improvements, and a
_number_ of improvements to comment prose and terminology to try and
avoid jargon and make things read more naturally. Sorry for the fact
that Claude left a bunch of this mannerly language in comments despite
my efforts, but I'm continuing to try and drive the prose towards
something direct and simple to read. Some of the terminology
improvements also needed to be made in the design doc and those have
been made here.

Note that I don't think this rendering is perfect or should be viewed as
final. I'm happy to iterate on it further, and have a few adjustments in
mind already, but would like to focus this on getting the
_implementation_ of the current rendering design in place, and then we
can make targeted changes or tweaks as needed. For example, I'm not yet
fully happy with the rendering when messages are too long and we move
them all the way to the left, but am leaving that for a follow-up.

Assisted-by: Claude Code
2026-10-31 06:10:03 +00:00
Chandler Carruth 2c9739799b Render diagnostics through the terminal library (#7683)
Diagnostic rendering was part of the data model: `Loc::FormatLocation`
and
`Loc::FormatSnippet` wrote plain text to a stream, so no capability,
color, or
terminal width could reach them.

A diagnostic is now one message with labels, contexts, and location
information
attached, and `Diagnostics::Renderer` draws it into a
`Terminal::Buffer`. The
design is in `toolchain/docs/diagnostics_rendering.md` (#7668),
authoring in
`toolchain/docs/diagnostics.md`.

Before:

```
example.carbon:6:3: error: 1 argument passed to function expecting 0 arguments
  Run0(1);
  ^~~~~~~
example.carbon:3:1: note: calling function declared here
fn Run0() {}
^~~~~~~~~~~
```

After:

```
error: 1 argument passed to function expecting 0 arguments
       ╭─┤ example.carbon:6:3
       ┆
     3 │ fn Run0() {}
       · ─────┬─────
       ·      ╰──┤ calling function declared here
       ┆
->   6 │   Run0(1);
       ·   ───────
       ╰────────────
```

`--no-diagnostic-snippets` gives a compact form, `example.carbon:6:3-9`.
File
tests use it; the rendering tests under `toolchain/diagnostics/testdata`
ask for
snippets.

C++ interop diagnostics are data now rather than text Clang drew:
`SemIR::ClangSourceLocId` names a `clang::SourceRange`, and a Clang
location is
marked as the point it names.

`StreamConsumer` moves to a `:renderer` target that `:emitter` does not
depend
on, keeping `common/terminal` out of `consumer.h`. Capabilities come
from the
file behind the error stream, so tests get plain ASCII.

`renderer_fuzzer` draws diagnostics built from fuzzer bytes with every
capability combination, since a shape the renderer doesn't expect must
never be
why the compiler dies while reporting a problem.

TODOs mark the follow-ups: line weights and crossing lines, wrapping
that keeps
a quoted type whole, and ordering diagnostics that share a byte offset.

Also: `IncorrectExtension`'s hint moves into its message, since its note
had no
location of its own, and `strip_noise` in `check_diagnostics.py` blanks
multi-line `#define`s instead of deleting them.

Assisted-by: Claude Code
2026-10-15 06:08:57 +00:00
Richard SmithandChandler Carruth c588eadb57 Rename and rearrange entities in tests to avoid name reuse (#7656)
Fix a bunch of cases where we use the same external name to mean
multiple different things in the same test. We've historically gotten
away with this, but under `--share-cpp-ast`, it becomes an error, at
least if the entity is either defined in, or used from, C++ code.

Assisted-by: Gemini via Antigravity (original change) and Claude Code
(suggested edits in review)

---------

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2026-08-21 01:36:40 +00:00
Richard Smith c278bea3c5 Support LP64 platforms such as Darwin where int64_t is long long. (#7596)
Add `Core.CppCompat.[U]Long64` to represent a 64-bit long that is not
`i64`. Treat it as being "just slightly smaller than" `i64`, like we
treat `Core.CppCompat.LongLong64` as being "just slightly larger than"
`i64`, so that we get implicit conversions `Cpp.long` -> `i64` ->
`Cpp.long_long` on all targets.

This follows the direction of proposal #5448, and seems like the obvious
extension of the `[U]Long32` and `[U]LongLong64` types added in #6275
for targets of this "shape".

Assisted-by: Gemini via Antigravity
2026-08-07 16:10:01 +00:00
Dana Jansens 9b8a2124b9 Don't require non-class types to be complete to convert from them (#7590)
In Convert, we require the source value's type to be compete so that we
can look for `base` classes and `adapt` relationships. However these can
only be present in a `ClassType`, so we only need `ClassType`s to be
complete.

Reduce the requirement in Convert to not complete types that are not a
`ClassType`, and which can not contain a `ClassType` as part of their
class.

Ideally we would only _only_ require the `ClassType` itself to be
complete, and only if we're looking for a base or adapt. However lower
depends on us completing all Convert source types that contain a class.
This seems to suggest we're lacking checks for complete types somewhere
else and Convert is making up for it. A TODO has been added. The
`toolchain/driver/testdata/compile/optimize/optimize_debug.carbon` test
is an example that CHECKs due to failing to verify the LLVM module if we
do not compute the complete type of all class-containing types in
Convert.

The critical step this PR is doing is to stop trying to complete a
`FacetType` when converting from a facet. This avoids trying to complete
a named constraint when converting `Self` inside that named constraint.
Doing so causes a cycle when the conversion of `Self` is performed in
eval of an `extend require` decl, since requiring the named constraint
to be complete re-evaluates the `extend require` decl again. A test is
added that crashed in an infinite loop before this change.

It also depends on #7584, which was intended to be an optimization but
is now load bearing. Because converting `Self` leaves an impl lookup
inst behind, and if that inst is re-evaluated inside impl lookup (by
forming a specific of a `require` decl through identify) then we have a
similar cycle.
2026-07-31 17:35:21 +00:00
Dana Jansens f51c075f8b Avoid symbolic witnesses for .Self in an impl decl (#7564)
Point symbolic witnesses into `.Self` written inside an impl decl at the
impl that is being declared. This is tricky because the impl does not
yet exist. So we use a new instruction `ImplSelfWitness` which _will_ be
replaced by the `ImplWitness` once it becomes available. The
`ImplSelfWitness` acts like a symbolic witness, except it does not
perform lookup, since we know which impl we will get a witness from.

This prevents us from finding other impls when performing lookups into
`.Self` in an impl decl, which produces incorrect/incoherent results.
2026-07-29 16:25:23 +00:00
Richard Smith a8afc45ed5 Omit empty observe: blocks from formatted SemIR. (#7487)
Also add SemIR ranges to observe test, removing 5K lines of
uninteresting SemIR output.
2026-07-13 20:38:19 +00:00
Chandler Carruth 8be274cf60 Replace :! binding syntax with phase keywords and contextual defaults (#7479)
Implement the toolchain side of proposal #7254, removing the `:!`
binding
syntax for generic and template parameters in favor of the keywords
`generic`,
`template`, and `runtime` plus contextual defaults for phase.

For valid programs this is semantics-preserving: each binding resolves
to the
same phase, and produces the same SemIR, as it did under `:!`/`:`. The
parser
derives a binding's phase from its syntactic context plus any explicit
phase
keyword; new diagnostics and error recovery for misused keywords are
described
below.

Implementation details for each component:

- Lexer: remove the `:!` (`ColonExclaim`) token, move its virtual
parse-node
  budget onto `:`, and add the `generic` and `runtime` keywords.
- Parser: thread a `BindingContext` (`ExplicitParam`, `DeducedParam`, or
`CompileTimeEntityParam`) from declaration introducers down through
parameter
lists to each binding pattern, using a one-token lookahead to
distinguish a
name-qualifier parameter list from a declaration's own final list.
Parameters
of a compile-time entity (`class`, `interface`, `constraint`, `choice`,
`alias`, `export`, `namespace`) and deduced `[]` parameters default to
checked
generic; explicit function parameters and local bindings default to
runtime.
`HandleBindingPattern` resolves the phase from that context plus the
keyword: a
`generic` keyword needs no node of its own (the phase is carried by the
  binding's node kind), while a `runtime` keyword is preserved as a
`RuntimeBindingName` node so `check` can name it in a diagnostic. A
phase
keyword that is merely redundant with the contextual default is
diagnosed
  here, without invalidating the parse tree.
- Check: a phase keyword that is invalid for its context (for example
`runtime`
on a checked-generic parameter) is diagnosed here, and recovers by
building an
error binding that still introduces the name so that later uses of it do
not
  produce cascading errors.

The removed `:!` syntax is now rejected as an ordinary parse error.

The `form`/`:?`/`->?` ("extended types") portion of proposal #7254 is
left for a
separate change.

Assisted-by: Claude Code
2026-07-11 01:22:44 +00:00
Dana Jansens 4261bb2dd2 Track and don't replace active .Self (#7443)
In #7436 we stopped substituting `.Self` when collecting witnesses out
of a facet type. While this was correct, it did not capture all the
cases that need to avoid substituting `.Self`. And it poisoned the
`IdentifiedFacetType` cache by not replacing `.Self` but storing the
result in the cache. This led to incoherent behaviour, where the result
of an impl lookup would change depending on which ones had been done
previously.

Now we use a flag to track for each `.Self` if we're currently
type-checking inside the scope where it was introduced in a facet type.
While inside that scope, identify should not replace the `.Self`. Any
use of it should remain as-is since we don't yet know what value will
replace it. We call this state "frozen" since it should not be modified
by identify. This requires a substitution step when we leave the scope
that introduced the `.Self`, to remove the flag. The flag is set in the
`EntityName` of the `SymbolicBinding`, and is part of the canonical
value, since `.Self` can become part of types, which are constants, and
the flag needs to follow it for correct behaviour.

We also have to ensure the flag is the same when doing comparison with
constants from inside a facet type and constants from outside. For
instance in `(Z where .Z1 = ()) where .Z2 = .Z1`, when we arrive at the
second `.Z1` its `.Self` will be frozen, while the `.Z1 = ()` contains a
non-frozen `.Self`. So we add the frozen flag to the first when storing
it in `where_stack` in order to compare the constant values of the two
`.Z1`.

The `WhereExpr` requirement inst kinds now have an `InstConstantKind` of
`AlwaysUnique` instead of `Never`. This allows us to add them to the
usual InstBlocks, and in an `eval fn` body they have a constant value,
so eval does not fail when trying to call that function. We have to be
careful to not consider `AlwaysUnique` as being actually concrete
though, since their constant value erases `.Self`-dependence. This
allows us to stop special casing them when thawing the requirements
block in a `WhereExpr`, and we can just thaw each `InstId` in the block
in a straightforward manner.

We add the new flag to the instruction's fingerprint and name in
formatted semir.
2026-07-08 18:04:56 +00:00
Özgür T. ÖnsoyandDana Jansens 08385adeb5 Implement checking observe declarations (#6709)
This adds SemIR structs and implements building `observe` lists, as well
as naming, formatting, and importing `observe` declarations.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2026-07-08 17:07:10 +00:00
Geoff Romer 8945305dfc Emit NameBindingDecl after the initializer (if any) (#7467)
In some cases the pattern block can depend on the initializer, so it
must be sequenced after it. See #7469 for a more detailed explanation of
why this is necessary.
2026-07-07 19:18:33 +00:00
Geoff Romer e4b0903d2e Remove ValueBinding and RefBinding (#7427)
These inst kinds are now redundant with `WrapperBinding`.
2026-06-29 17:41:23 +00:00
Geoff RomerandRichard Smith e023f75254 Implement thunking in terms of constant evaluation (#7332)
The bulk of this change is changing most pattern insts to be `Always`
rather than `AlwaysUnique` constants, so that they can be wrapped in
`SpecificConstant`s to perform substitution. That then lets thunking
rely much more on `SpecificConstant` wrappers instead of deep-copying
the inst tree with modified types.

This approach to thunking should scale better, particularly as things
like form generics make function signatures more complex, because we can
leverage the existing support for constant evaluation and substitution.
Unfortunately, applying this approach to binding patterns will require
more work; see the TODO near the top of `thunk.cpp` for details.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-06-13 00:22:00 +00:00
Richard Smith cefa0397bb More fixes to package and library fingerprinting. (#7297)
Fix import logic to make all imported packages be children of the
`NameScopeId::Package` scope. Previously, indirectly-imported packages
would end up as children of their importing package's scope, which
resulted in them not being treated as packages at all, and in particular
not being fingerprinted as packages.

Fixing that caused a failure in the fingerprinting logic as we started
to encounter packages with no correspoding import scopes. Instead of
looking for import scopes, use a simpler mechanism to map packages to
their package names, and clean up.

Unfortunately the latter change churns all the fingerprints again :(
Hopefully this is the last time for a while.
2026-06-04 17:41:46 +00:00
Richard Smith f5e9c61f11 Don't include the library name in most fingerprints. (#7292)
When we import from another library in the same package, its entities
end up with our library as their parent scope, resulting in cross-file
fingerprint mismatches. Instead, only include the library ID when
fingerprinting either a package-private entity or an `ImportIRId` that
refers to a particular `SemIR::File`.
2026-06-02 19:31:30 +00:00
Chandler CarruthandChristopher Di Bella 8a59f2a76b Fix mangling collision for C++ class template specializations (#7269)
Carbon-side thunks (for example the `Copy`/`Destroy` witness thunks
generated for imported C++ types) are mangled by Carbon, and their names
incorporate a fingerprint of the involved types. The instruction
fingerprinter identifies a class only by its name and parent scope,
which is sufficient for Carbon classes but not for imported C++ classes:
different specializations of one class template (and other cases such as
types in anonymous namespaces) share a Carbon name and parent scope. As
a result, the thunks for two distinct specializations could mangle to
the same name, producing a single LLVM function with two definitions and
failing `verifyModule` during lowering.

When fingerprinting a class imported from C++, also include the Clang
mangled name of its type.

Test: toolchain/lower/testdata/interop/cpp/thunks.carbon gains a split
with two specializations of one class template, each requiring a thunk;
their thunks now get distinct mangled names instead of colliding.

Assisted-by: Claude Code

---------

Co-authored-by: Christopher Di Bella <cjdb.ns@gmail.com>
2026-05-30 08:13:00 +00:00
Richard Smith 05cc09daca Fix cross-package signature mismatches. (#7232)
Fixes link failures when referencing a symbol involving a fingerprint
from a different package.

Previously we included the `Namespace`'s `import_id` as part of its
fingerprint, which caused local and imported namespaces to get different
fingerprints. We now store the `import_id` on the `NameScope` instead of
on the `Namespace` inst to avoid this problem.

Also, when we reach a package-level `NameScopeId`, consistently
fingerprint it as a (package name, library name) pair. Previously the
fingerprinting depended on whether it was imported or not, as an
imported `NameScopeId` had a parent scope (the current package). We need
to include the library name here so that private entities with the same
name in different libraries have different fingerprints.
2026-05-21 00:02:29 +00:00
Dana Jansens f8dd4d85bf Do not treat impls in different scopes as redeclarations (#7161)
An impl in a different scope, with the same parameters, will overlap and
get diagnosed for that later by the [prioritization
rule](https://docs.carbon-lang.dev/docs/design/generics/details.html#prioritization-rule),
if they are not in a match_first block. But they are not considered as
redeclarations.

See [proposal
p5366](https://github.com/carbon-language/carbon-lang/blob/62b94f79322039acc3fc8e175896a64a32df470e/proposals/p5366.md)
for the rule.
2026-05-04 19:11:51 +00:00
Dana Jansens 88931a4196 Give the .Self instruction a location (#7147)
This lets us stop eliding it in textual semir tests with dump ranges.
Previously it would always get elided, even though it was part of the
range being dumped, and was referred to by other instructions in the
dump range.

Since each `.Self` is unique (can change its type if not its value) in a
facet type, having each one distinct by location also aids
understanding.
2026-05-04 14:45:06 +00:00
Dana Jansens 554b1b8d10 Remove SymbolicBindingType (#7114)
This inst was meant to support tracking the depth of a `.Self` facet,
but we have now implemented substitution of `.Self` in facet type
identification, and in eval of where expressions, without needing to
track the depth.

See history here:
-
[2025-06-30](https://docs.google.com/document/d/1Yt-i5AmF76LSvD4TrWRIAE_92kii6j5yFiW-S7ahzlg/edit?tab=t.0#heading=h.4qd5dkyfn2k3)
-
[2025-07-07](https://docs.google.com/document/d/1Yt-i5AmF76LSvD4TrWRIAE_92kii6j5yFiW-S7ahzlg/edit?tab=t.0#heading=h.7urbxcq23olv)
- #6026
2026-04-27 19:04:59 +00:00
Richard Smith 335d811b9f Add a bit more structure to interop/cpp tests. (#7085)
Add import/ and export/ under function/. Move most top-level tests to a
new basics/ with subdirectories for `import` directives and `inline
Cpp`. Add subdirectory for primitive type handling. Move all `reverse/`
tests to somewhere else, typically under an `export/` directory.

I split two test files up: constexpr.carbon got split into var/ and
function/ pieces, and reverse/simple.carbon was inlined into
namespace/export.carbon. The rest are just simple renames.
2026-04-21 20:22:21 +00:00