This fixes some bugs in each, where the fixes had only been made on one
side of the switch or the other. Also don't forget to instantiate
deduced generic arguments in a call when we read them out of the AST.
This is intended to address currently flaky timeouts that are likely caused by the size of the prelude. I'm addressing a performance bottleneck in AnalyzeProgram with trace output. Trying to omit prelude traces reduces most trace output significantly, and I think it'll scale better as the prelude size increases.
The basic mechanics here are:
- In order to consistently track whether tracing is on, I've added a TraceStream class, explorer/interpreter/trace_stream.h.
- The AST now has a num_prelude_declarations field, so that it's provided where the boundary is.
- In order to mark where we try to skip prelude output, I've added calls to set_in_prelude in type_checker.
- In exec_program, I just use num_prelude_declarations directly to skip over.
- Everywhere checks TraceStream::is_enabled before printing, similar to the std::optional check that was previously used.
This does add some timing output in order to better diagnose where slowness is coming from, when tracing. It also adds "verbose" targets to make it easier to get the trace output.
So for example, here's a timing for zero.carbon:
```
Timings:
- Parse: 13ms
- AddPrelude: 25ms
- AnalyzeProgram: 116ms
- ExecProgram: 12ms
```
If I make a small change to just not set skipping_prelude (essentially getting back to current output):
```
- Parse: 13ms
- AddPrelude: 25ms
- AnalyzeProgram: 2359ms
- ExecProgram: 57ms
```
Thus in this trivial example, I'm eliminating about 95% of the execution time.
Note this approach could still be refined in a few ways:
- We could add a flag to allow overriding in_prelude. It should be a small amount of work after this change. But it's a little consistent with how parser_debug works, that it won't print prelude output by default (unless there's an error).
- Execution could skip messages involving initialization of globals declared in the prelude. This is a little noisy right now, but I don't think it's significant for performance because ExecProgram is tiny.
- Once files are more separated, we should be able to change the num_prelude_declarations/set_in_prelude approach.
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Both cases need a label for each level of struct and tuple type appearing in the impl query, because we can have an unbounded number of such levels with the types otherwise being the same.
Prior to this, both added testcases exhibit unbounded recursion.
Detect when evaluating an impl recursively tries to evaluate the same impl for the same or a more complex set of parameters.
In order to perform the check after we have tested that the type structure matches and before we check that constraints are recursively satisfied, argument deduction is extended to check structural matching properties earlier.
This requires us to separate match failures into two kinds: hard failures that produce errors that should never be swallowed, and soft failures such as a missing impl that lead us to merely discard an impl as a candidate. A flag has been added to `ImplScope` and `ArgumentDeduction` to specify whether soft failures should produce an error message or not.
The design of choice types expects the declaration of an alternative to match the usage: if an alternative is declared as `None`, then it should be used as `None` not `None()`, and if it is declared as `None()` then it should be used as `None()` not `None`. Update explorer to match.
Also clean up the handling of choice types and alternative values a little in general, by moving away from identifying choice types and alternatives as strings and towards identifying them symbolically.
Closes#2422
Return Integer overflow Runtime error for bit shift if The second operand is less than zero or bigger than or equal bit width of the first operand in this case (32 bit for int)
Issue #2595
Support for global variables is still missing; they're a bit more tricky because they use a pattern to introduce their name.
Prior to this change, explorer heavily relied on name comparisons to determine whether two declarations declare the same entity. Some of those instances are fixed in this PR, but more remain to be fixed, and some TODOs are added for some harder-to-fix instances.
Name lookup into namespaces needs to be resolved early, as part of name resolution, so that we can properly diagnose references to entities before they are fully declared. Make name resolution set a target `value_node` on simple member accesses that name namespace members, and in type-checking rewrite those member accesses into `IdentifierExpression`s that directly reference the namespace member.
First step towards permitting declarations within namespaces. Supports only functions within namespaces for now, with no way to call those functions except from within other such functions. Unqualified lookups within a function in a namespace look in that namespace first.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
As per the `TODO` comment in the file, the `CallableDeclaration::name` property was refactored into `FunctionDeclaration`, which is currently the only namable callable declaration kind. I was able to rely on the existing `GetName` function to replace call sites of the accessor function with nearly identical swaps.
Fixes#2531
Move deallocation logic to `StepCleanUp` to have all necessary cleanup actions in the same place. Currently this means `DestroyAction` and `heap_.Deallocate`.
Fix variables not being properly cleaned up if declared before an unformed variable.
### Details
Currently the following example / test
```
package ExplorerTest api;
class A {
var i: i32;
destructor[self: Self] {
Print("Destructor A {0}", self.i);
}
}
fn Main() -> i32 {
var a0: A;
var a1: A = {.i = 1};
var a2: A;
var a3: A = {.i = 3};
return 0;
}
```
prints
```
Destructor A 3
```
instead of
```
Destructor A 3
Destructor A 1
```
This PR fixes the issue in the `CleanUp` logic.
Add support for user-defined assignment, as well as compound assignment and increment, following the design direction in pending proposal #2511.
Some of this isn't fully testable yet: because explorer doesn't properly support `impl` specialization, the blanket `impl`s in the prelude prevent types from customizing assignment.
Naming this ToString within the Carbon namespace encourages incidental overloading of the function, and that doesn't seem to be intentional; this feels questionable [under overloading style](https://google.github.io/styleguide/cppguide.html#Function_Overloading). OperatorToString seems helpful in that it makes it easy to see at a glance where it's being used.
Add a check to prevent creating a class from a struct with a missing parent.
This is already type-checked for carbon / user code, but not when using `Convert` manually.
Add a blanket `ImplicitAs` implementation to perform the conversions that explorer can perform as built-in conversions. This allows those conversions to be detected by constraints and to be used as part of other user-defined conversions. For now, a single monolithic conversion is exposed. I intend to split this up into multiple smaller conversion kinds for each kind of conversion in a follow-up change.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Add basic support for `match_first` declarations to explorer, as described in https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/generics/details.md#prioritization-rule. The concrete syntax here is not yet approved, so `match_first` is renamed to `__match_first` for now, but the semantics are necessary to implement other approved features in explorer so we're intentionally getting a little ahead of the design here.
Improves the error produced when 'Main' is declared with parameters. Resolves a TODO in the typechecker. Explorer only.
PR also adds a test for this error message.
Currently, only the action class uses the noun case (`Cleanup`), while the kind enum and functions are spelled `CleanUpAction`. Other actions use consistent casing between class and enum names. This change makes the name consistent, and unsurprising for developers. Mirrors `DestroyAction` (verb).
Also make minor updates to the skeletal design in
docs/design/name_lookup.md following #2113, as there are no longer any prelude names that are made available to unqualified name lookup by default.
Add `type` to the keyword list in
docs/design/lexical_conventions/words.md, following #2360.
Features:
* Add basic support for `impl` virtual methods (override virtual method)
* Error on invalid declaration for `impl` and `virtual`, covering simple use cases
* Add `abstract` fn parser-only support
Changes:
* Modify parser to handle new function specifiers, resolve conflicts
* Group `virtual_override` and `FN`, and group `impl_kind` and `IMPL` to avoid ambiguities with around `impl` token parsing
* Add new `VirtualOverride` enum for function declarations, and matching `virt_override() -> VirtualOverride` getter
* Update function declaration logic
Depends on #2462
Features:
* Add `virtual` virtual override keyword for functions
* Support `virtual` class methods using dynamic dispatch
Changes:
* Add `vtable` in `NominalClassType`,
* Add `NominalClassValue**` in class values pointing to descendant-most class
* Resolve virtual methods during member lookup
Limitations:
* Does not include yet `impl`, `abstract` virtual override keywords, or the complete logic for virtual function declaration
Depends on #2460
Relates to #1881
Relates to #2493
Protobufs code hits a warning with the latest system headers on macOS.
I figured this may have been fixed so I updated protobufs and Bazel to
the latest releases. This generally cleaned things up.
However, it actually added *more* warnings. This clearly isn't a really
well tested path. In fact, we already have a disabled warning that we'd
like for Carbon code because LLVM isn't clean for that warning.
So I've switched our warning strategy to a more durable approach of
suppressing all warnings for external repository headers and source
files. This lets us re-enable the missing warning and should fix the
protobuf warning that started me down this twisty path.
Sadly, we *have* to update to Bazel 6 in order to have the necessary
flag to use this approach to suppressing warnings, so I couldn't do this
as two PRs cleanly. =/ That's why I've bundled both the Bazel (and
protobuf) updates with the warning strategy change.
Last but not least, I've fixed several unused parameters in Carbon's
code that our warnings now catch.
Addresses comments from this discussion: https://github.com/carbon-language/carbon-lang/pull/2460#discussion_r1046444433
Features:
* Move subtyping logic from Interpreter to TypeChecker, exposing subtyping as a series of access to `.base`.
* Excludes function parameter conversion, which is still done in ::Convert due to parameters conversion being handled differently.
Changes:
* Add new `class BaseAccessExpression : public MemberAccessExpression`, allowing rewrites
* Handle `BaseAccessExpression` expression type in Interpreter
* Move subtyping logic to `TypeChecker::ImplicitlyConvert`
Add a generic mechanism to decompose a `Value` and rebuild it, and use that to implement `Substitute`'s recursive transformation of values instead of a hand-rolled decomposition. This means `Substitute` now covers all kinds of values, whereas previously it used to be unable to transform some values, and should be less work to add new kinds of value.
We can use the same mechanism for various other things: structural dumping of values, equality comparisons, and value instantiation in the interpreter would all benefit from this. But in this change I'm just switching `Substitute` to this as a first step.
Depends on #2361, #2421
Add support for destructors of base classes.
Features:
- Call destructors from derived to base class
- Support addressing `TupleValue` using a new `Member` variant
Changes:
- Update `StepDestroy()` to recursively call destructors from derived to base class
- Add new `Member` variant and `IndexedValue` struct to be usable with `TupleValue`
Features:
* Split `Member` class into 3 dedicated classes covering named, positional, and a new "base class" element
Changes:
* Rename `Member` to `Element` to better reflect the variants covered
* Add `NamedElement`, `PositionalElement`, and `BaseElement` child classes for `Element`
* Split `GetMember` into 3 function variants based on available attributes (index, name, nothing).
* Add some unit tests to provide coverage of core features
Motivation:
This changeset splits Member into (currently 2) classes, as we see the need for more Member variants (base class access needed for #2378, possibly unnamed mixins, ...), which in addition to the current ones, also have significantly different attributes. This will allow supporting more Member types in the future cleanly.
Alternatives considered:
The alternative solution, "one class for positional, named & base class access", would expose unused or unavailable attributes depending on the Member actual type (`index()` only for positional, `name()` only for named, and neither for base class access).
Features
* Support addressing positional members (i.e. tuple fields) using an index.
* Addresses a couple of `TODO`s relative to positional members
Changes:
* Add a new `IndexedValue` mirroring `NamedValue`
* Adds `FieldPath::index() -> int`
* Adds a `Member` variant for `IndexedValue`
Relates to #1881
Features:
* Add basic support for `abstract` class
* Allow extending an abstract class
* Prevent direct instantiation of an abstract class
Changes:
* Check that class extensibility for `VariableDefinition` is not `Abstract`
* Add corresponding set of lit tests
LLVM's bazel build has changed a bit, so this updates the tree for that.
LLVM is also moving `llvm::Optional` to match the standard API, but it seemed simpler to just switch to `std::optional`.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Relates to https://github.com/carbon-language/carbon-lang/issues/1881
- Add support for `.base` field in structs for [parent class initialization](https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/classes.md#constructors)
- Disabling base class initialization without `.base`
- Support class constructors (`Create() -> Self`) for base classes
- Direct access to base class(es) attributes with `object.var` remains unaffected
Changes:
- Add `TypeChecker::FieldTypesWithBase` to help assessing if a struct with `base` fields can be converted to a class
- Add a new `base_type()` attribute+getter to `NominalClassDeclaration` to as a first step to allow resolving parametrized classes
- Add a new `base` attribute+getter to `NominalClassValue` that contains the base class `NominalClassValue`. It is currently used mainly to get and set members of a class object.
- Add `Interpreter::ConvertClassWithBase` to build `NominalClassValue` from a init struct, that contains `.base` fields with either `NominalClassValue` or `StructValue`
- Add `FindClassField` to find a field in a class or its base classes
- Remove superfluous `ClassDeclaration::base()` in favor of `ClassDeclaration::base_type()`
Limitations;
- Though some work is done in that direction, parametrized base class where time is not know at the declaration site are not supported. Namely the example below does not compile
```
base class A(T:! Type) {}
class B(T:! Type) extends A(T) {}
```
But this one is functional already
```
base class A(T:! Type) {}
class B extends A(i32) {}
```
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Patterns all compute their values when type-checked, so we never
actually need to do any multi-step evaluation to compute the value of a
pattern. Doing so was leading to quadratic runtime and excess noise in
the trace file.
This PR includes the following changes:
* Added destruction process for tuples
* Fix: In the current version only the last member of a object can be destroyed
* Fix: In the current version, the destructor of the object is called after each method call
I hope it is useful
Co-authored-by: m new <michael.burzan@outlook.de>
Co-authored-by: Geoff Romer <gromer@google.com>
In particular, this means that a type can implement `ImplicitAs(Type)` and have values of that type behave like types.
This implies that `()` and `{}` are no longer types. They are now values whose type is the result of converting `()` or `{}` to type `Type`, as has been discussed recently and seems to be the supported direction. This fixes various cases where these types were previously mishandled.
When resolving a constraint type, compute the fixed point of the specified rewrite constraints, as requested by @josh11b in review of #2173 and tentatively agreed as our direction. If no such fixed point exists, detect that situation and diagnose the problem.
The algorithm used here is to iteratively apply all rewrites to each rewrite constraint until either one of them refers to itself, which indicates there's a cycle in the rewrite graph, or the set of rewrites converges.
This algorithm has some pathological inputs in which the runtime can grow exponentially in the size of the input (indeed, the fully-rewritten set of rewrites can grow exponentially in the size of the input, so this is unavoidable), so an iteration limit is also provided.
Richard Smith
Jon Ross-PerkinsandRichard Smith
Amr Hesham
Adrien Leravat
Calvin
Carson Radtke
Chandler Carruth
josh11b
