Some of the macros tests were not printing the SemIR. Printing it can
help spot issues (as in PR #6440), so added that now for all passing
tests.
Part of #6303
If an impl lookup finds a final result, cache that and reuse it if we
perform the same lookup later.
In addition to reducing repeated work, this allows us to produce the
same result for repeated lookups that find a C++ operator. This isn't a
great solution to that problem, as it's not clear how to extend it to
behave correctly across import, but we don't have a solution for that
for C++ interop in general.
Errors that occur while constructing a specific should be tied back to
the facet type being identified. We don't have an InstId for the facet
type during identify, so provide the means to Stringify a FacetTypeId.
Depends on https://github.com/carbon-language/carbon-lang/pull/6435
When performing impl lookup for `Core.Copy` for a C++ class type, look
for a copy constructor. If we find one, synthesize an impl witness that
calls the constructor.
This adds initial support for impl lookup to delegate to the C++ interop
logic for queries involving C++ types. For now, we don't implement the
rules from #6166 that compare a synthesized type structure for the C++
impl against the best Carbon type structure, but the framework for
building that support is established here.
Currently there is no caching of the lookup here, and we build unique
`ImplWitnessTable`s for each lookup, which leads to each impl lookup
producing a distinct facet value. This results in some errors in generic
contexts; this will be addressed in follow-up changes. This PR aims only
to support the non-generic case.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
The FacetTypeId should never be used directly, since the RequireImpls is
a generic and the facet type may be parameterized by generic bindings.
So instead, it should be accessed through GetConstantValueInSpecific,
which works with the facet type InstId that is also already present on
RequireImpls. This change to use GetConstantValueInSpecific was done in
#6435, so the FacetTypeId is now unused except in formatting. So we can
remove it.
This depends on #6435.
When forming an IdentifiedFacetType, we collect interfaces named by
require decls in named constraints that the facet type refers to. These
interfaces come with a specific, but the require decl is inside an named
constraint which may be generic. So we need the specific being applied
to the containing named constraint to also be applied to the require
decl and its target interfaces.
This uncovered that the facet type in require decls was not being
imported correctly, as it was not being attached to the require decl's
generic. This is fixed by making import of RequireImplsDecl multiphase,
so that the decl instruction exists before we resolve the facet type
within it. And by pointing the generic importing machinery to the
RequireImplsDecl, and from there to the RequireImpls structure to get
the generic id.
Then `ImplStore::GetOrAddLookupBucket` can use an IdentifiedFacetType to
correctly get the interface being impl'd, both in the local and the
imported named constraint case. Which allows us to correctly diagnose
redeclarations in the impl file of an impl of an interface through a
named constraint. And to correctly _not_ diagnose them when the specific
in the generic named constraint differs from other decls.
This builds on the previous work to flesh out more on-demand runtimes
building. It adds building of the `libc++.a` archive runtime.
A number of changes are required for this to work:
- The runtimes build infrastructure needs to support building sources
from multiple parts of LLVM rather than a single part. We do this by
lifting the root of the runtimes source paths up a level to a common
runtimes tree, and installing the runtimes sources below this
directory.
- Both libc++ and libc++abi runtimes sources need to be installed, and
we even need to install some interesting parts of llvm-libc that are
used in the build of libc++.
- We need to generate the site configuration header file for libc++ from
the CMake template. This includes both setting up a set of
platform-independent defines and introducing some basic Bazel support
for processing the CMake template itself.
Doing all of this also exposed some missing features and limitations of
the runtimes building infrastructure that are addressed here.
One note is that all of this just adds libc++ to the explicit
`build-runtimes` command for testing. It doesn't yet trigger
automatically building these prior to linking, or configuring any of the
other subcommands to automatically use these runtimes. All of that will
come in follow-up PRs.
Also, this makes the `clang_runtimes_test` ... _very_ slow in our
default build configuration. Compiling libc++, even with many threads on
a large Linux server requires up to 50 seconds. I'm open to any
suggestions on how to handle this, including disabling the test in
non-optimized builds. I have some ideas to speed this up, but
fundamentally building libc++ is... not cheap.
I did look at some of the existing Bazel tools to process the CMake
template, but they all seemed significantly more complex than what we
need and didn't have broad adoption. Given that, it seemed slightly
better to just roll our own given the simple format.
Two of the new LLVM patch are currently under review upstream and so
hopefully temporary:
- https://github.com/llvm/llvm-project/pull/169155
- https://github.com/llvm/llvm-project/pull/169292
This extends #6364 to allow having:
* `Cpp.unsigned_long` as a distinct type when `unsigned long` is 32
bits.
* `Cpp.long_long` and `Cpp.unsigned_long_long` as distinct types when
`long` and `unsigned long` are 64 bits.
Similarly to #6364, we only support implicit conversions from the
matching literal type (`u32`, `i64` and `u64`).
See #6275 for rationale.
Part of #5263.
Even with `--benchmark_dry_run`, the benchmarks that use _batching_
still do one batch at a minimum as that's inherent to how batching works
in the benchmark framework.
This means that the minimum batch size can (and in practice does)
trigger timeouts by forcing 1k iterations in the test run that is just
trying to ensure the benchmark doesn't _crash_ in some way.
Reduce the minimum size to 128 instead of 1k for this benchmark which
should put it (much) further from any timeout limit. It also still seems
perfectly effective for getting good benchmark data -- I think the
original value was set _much_ too aggressively.
This adds just enough debug info for i32/int parameters and return
values, with a path forward for adding DWARF type metadata for other
types.
As it happens, return type information is carried separately from
parameter information:
* Return type information is carried in the `type` of the `DISubprogram`
(as a `DISubroutineType` - which does carry parameter type information
as well, but that's unused when the DWARF is emitted by LLVM)
* Parameter information is carried by `DILocalVariable`s with a non-zero
`arg` value (representing the order of function parameters)
In the absence of locations for the parameters (future work), nothing
would usually keep the `DILocalVariable` live/reachable when emitting
DWARF - so for cases where this can happen (for clang, this happens in
optimized builds where all references to the parameter variable might be
optimized away) the variables can be "retained" in a list on the
`DISubprogram` - achieved by passing `AlwaysPreserve` parameter to
`createParameterVariable` (adds them to a list, then that list gets
attached to the `DISubprogram` when it's finalized later)
For now, any unsupported types are emitted as `void*` (except void
return, which is implemented as void) as a placeholder.
Given this example:
```
import Core library "io";
class MyClass {
}
fn Unsupported(v: MyClass) {
}
fn Ret() -> i32 {
return 42;
}
fn Arg(x: i32) {
Core.Print(x);
}
fn Run() {
}
```
this is the resulting DWARF:
```
DW_TAG_compile_unit
DW_AT_name ("test.carbon")
DW_TAG_subprogram
DW_AT_name ("Unsupported")
DW_TAG_formal_parameter
DW_AT_type (0x00000066 "void *")
DW_TAG_subprogram
DW_AT_name ("Ret")
DW_AT_type (0x00000062 "int")
DW_TAG_subprogram
DW_AT_name ("Arg")
DW_TAG_formal_parameter
DW_AT_type (0x00000062 "int")
DW_TAG_subprogram
DW_AT_name ("Run")
DW_TAG_base_type
DW_AT_name ("int")
DW_TAG_pointer_type
```
And the debugger:
```
(gdb) p Ret()
$1 = 42
(gdb) p Arg(4)
4
$2 = void
```
I'm not sure if there's a way this logic should be merged with the logic
for making the `llvm::Function` type (which the `DISubroutineType`
building code was inspired by/copied from) - since they're done at
different times/places, I don't think there's an easy way to do it in
one pass, but maybe the code can be shared (even if it's run twice) in
some generic `SemIR::Function` type walker.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
Define rules for `extend` declarations (`extend require`, `extend impl
as`, `extend base`, `extend adapt`) that say the target scope they name
must be complete at the point of the declaration. Define completeness
for a facet type to include all interfaces and named constraints that
provide unqualified name lookup through the facet type.
---------
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
We already did this translation in the other direction, but we had no
mapping from `Optional(T)` to anything, so round-tripping a nullable
pointer from C++ through Carbon and back to C++ was previously rejected.
Right now, the impl lookup can both fail to resolve the specific
definition because it's symbolic, and return a "final" constant because
it's a `final impl`. This is adding an instruction to help ensure the
specific is resolved.
The constant evaluation is fully recursive, but I'm not adding a TODO
since that's a known issue with impl lookup in general.
Enum constants in a macro replacement list are recognized only when
prefixed with “::”.
There is a `todo` test to make explicit that this still needs to be
fixed.
When prefixed with a global scope “::”, they are correctly found and
evaluated to a const.
Part of #6303
Don't attempt to defer overload resolution by creating a
`CppOverloadSet`; this was incorrect as we weren't saving the complete
clang::OverloadCandidateSet, resulting in template candidates not being
found. Moreover, saving the overload candidate set would be expensive,
as the representation is surprisingly large, and is unnecessary since
we're about to build a call.
In passing, improve the diagnostics for overload resolution failure to
use Clang's operator overload resolution messages rather than its call
overload resolution messages.
This fixes calls to templated operator overloads, which is the final
piece needed for us to successfully compile an iostream-based "Hello
world" program.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
I was trying to figure out the right way to get specifics to be added to
the work.
Technically, we could keep the pending_specific list; this is taking a
different approach of inserting inside the work stack, which will do
extra work moving entries, although typically that should be expected to
be small. One challenge of `pending_specifics` is that if we would need
to shift them to work after both `Done` (for immediate processing) and
`Retry` (for processing after the current instruction is later revisited
and done). That feels kind of awkward as additional tracking to do.
Also, the common case is probably that there's either 0 or 1 specifics
being added, so an additional vector may be significant overhead. That's
why I leaned more in this direction of just inserting them in the vector
of work.
Identifying a facet type is an operation on a pair of (self type, facet
type). It substitutes that self in as the `Self` of any require
declarations in order to form the set of (self type, SpecificInterface)
pairs that constitute the requirements of the IdentifiedFacetType.
Currently we don't pass around any self type, and assume all require
declarations are written against `Self` but this will change in the
future.
By contrast, type completion is done in the abstract and does not form
specifics for the require declarations. The purpose of type completion
is to enumerate the scopes where name lookup can occur and ensure they
are completed.
With this change, type completion is:
- No longer built on top of identification for facet types.
- Recursively ensures all `extend` scopes are complete since name lookup
can find symbols in them.
We add some test cases that demonstrate consistency between a resolving
the specific of a generic class, and a generic interface/constraint,
both used in a type position. In all cases, an invalid specific is not
materialized for the type completion when the specific's arguments are
used in a non-extend context. But they specific is materialized and
checked for type completion when in an extend context (extend impl or
extend require).
Type completion itself does not need to recurse into named constraints
or interfaces as the `extend require` declarations require the type to
be complete immediately, just as for `extend impl` in a class.
We had a test (`fail_incomplete_where.carbon`) with `impl as J where
.Self impls K` and `J` is incomplete, which used to be diagnosed but no
longer is, because we don't require non-extend interfaces to be complete
in type completion, nor in identification. The test was trying to test
the presence of rewrite constraints though, which it didn't even use. So
we remove the diagnostic that we can't hit anymore and replaced it with
a TODO, and add a test that should reach that TODO once qualified
rewrite constraints work.
This builds the archive and checks relevant symbols are defined. While
here, this refactors the runtimes test to share much more code between
the different runtimes.
Last but not least, this adds a convenience type-def for the libunwind
runtimes builder.
There is an inconsistency between how we spell things as `Libunwind` or
`LibUnwind`. We should canonicalize on the former as it matches the
underscores and other things we will spell in this space. I'm not fixing
existing spellings in this PR but will send follow-ups for those.
For now, treat such classes as being final, since we can't correctly
derive from them.
This removes the last category of C++ class that we are entirely unable
to interop with, and is a prerequisite for interop with C++ iostreams
(which have a virtual base class).
For example, when developing against a checkout of LLVM, it is useful to
be able to consistently pass an override flag to Bazel for that
repository.
This lets:
```console
bazel test --override_repository=+_repo_rules+llvm-raw=$HOME/src/llvm/llvm-project //toolchain/...
```
and
```console
./scripts/create_compdb.py --extra-bazel-flag=--override_repository=+_repo_rules+llvm-raw=$HOME/src/llvm/llvm-project
```
Share the same Bazel cache and use the same flags.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
About the same # of LOC, but maybe less work to analyze correctness?
Versus the template, could also stamp that out in the helper function
and still avoid the duplication of calls before/after HasNewWork.
Similar to how I've left `rewrite_constraints`.
Alternately I'm also kind of tempted to rename GetLocalSpecificInterface
and GetLocalSpecificNamedConstraint to instead be overloaded functions
(or to provide overloaded versions), which would allow this to drop the
function type parameters. But, naming is hard.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
This test started failing with #6405, but it wasn't caught by our PR
testing or the merge queue as the test didn't _appear_ to be impacted by
the change (I think).
When run explicitly, as the post-commit actions do, it started failing
because of the new dependency edge.
This clarifies that the CC1 logic is directly extracted from Clang.
There are probably some other places in the toolchain we should extract
code like this where we're replicating and customizing logic from LLVM,
but wanted to start here.
This continues work to eliminate pending generics/specifics and get them
to be interleaved with instruction imports. I'm trying to use
`FinishGenericOrDone` here as a way to help ensure that code correctly
handles generics, where the simple alternative would be for each
`TryResolveTypedInst` call `SetGenericData` directly (but which might
make it easier to call the wrong `ResolveResult` function, and we do
need the `GenericId`s to be passed).
Avoid using a large switch that needs to be manually extended when
adding a new kind of instruction. Instead, the expression category for
an instruction is now specified when defining the `InstKind`.
In passing, add a distinct expression category value for patterns. This
isn't used for much except some error checking at the moment, but it
keeps the number of instructions that we need to manually classify as
`NotExpr` despite having a type very low.
Replace all unexpected instruction ids in a line, not just the first
one. Otherwise you get something like this:
```
// CHECK:STDOUT: impl @<null name>: <unexpected>.inst{{[0-9A-F]+}}.loc20_6 as <unexpected>.inst6000002E.loc20_11;
```
This is just an incremental step towards removing pending logic. The
rest seems like it'll be more complex due to interdependencies (I've
been poking at behavior).
Following #6357, map C++ `void` to a prelude class type
`Core.CppCompat.VoidBase`, not to a builtin type. This is mostly just
moving logic around, but does notably change `Cpp.void` from being an
incomplete type to being a complete-but-abstract type.
Also change `NullptrT` to be an adapter for `void*` instead of `()*`, to
follow the approved design.
Implicit conversions to `void` and to `void*` are still absent.
Part of #6280.
Since `ValueStore` now separates its id and value types as two template
parameters, we can use a `ValueStore` of `optional<ValueType>` as the
storage instead of a `SmallVector`.
Otherwise the value fails in confusing ways while untagging:
CHECK failure at ./toolchain/base/value_store.h:71:
index >= initial_reserved_ids_: When removing tagging bits,
found an index that shouldn't've been tagged in the first place.
With this change:
CHECK failure at ./toolchain/base/fixed_size_value_store.h:112:
id.index >= 0: instFFFFFFFFFFFFFFFD
Ivana Ivanovska
Richard Smith
Dana Jansens
Boaz Brickner
Chandler Carruth
David BlaikieandDana Jansens
Jon Ross-Perkins