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>
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
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.
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.
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 `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
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
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.
Prior to this change, declarations like `let N:! X(.Self) where .(X(.Self).Y) == 5;` have the surprising behavior of the two `.Self` expressions resolving to two different symbolic values. Fix this by forcing the inner one to have the same symbolic value as the outer one, albeit with a different type.
Per recent discussion, in `... where .A = B`, require that `B` is implicitly convertible to the type of `A` immediately, rather than treating that as part of the criteria that a type must satisfy to satisfy the resulting constraint. Extend the implementation of implicit conversion so that conversion of a type to a constraint checks that the type satisfies the constraint.
As part of implementing this, stop duplicating rewrite constraints as equality constraints. Instead, when checking that a constraint is satisfied, check both its equality constraints and its rewrite constraints. This fixes an infinite recursion that would otherwise be caused by this change, and is also a necessary prerequisite for applying rewrite constraints to equality constraints, where we would otherwise collapse the implied equality constraints to a tautological `V == V` constraint.
In passing, make ErrorBuilder support building the error message more incrementally and use that to improve diagnostics for mismatched values with equality constraints.
This does some more work to the run_clang_tidy.py wrapper script, and runs an example pass.
"again" because it's really the proto fuzzer changes that broke it, it had been working before.
"mostly" because there's still an issue within the proto fuzzer that it can't find "port/protobuf.h", i.e. https://github.com/google/libprotobuf-mutator/tree/master/port, but I'm still hesitant to add an include path there.
We don't seem to have any need for `TypeOf*Type` types, and having them introduces the temptation to use them during type-checking, which would lead to types having different behavior when their type-of-type is `Type` versus when it's a more precise type. Remove these types for now.
If we later decide that we want each type literal to have a unique type, as we do for value literals, we can introduce a single value kind for that rather than one for each kind of type.
No changes to `TypeOfMemberName`, `TypeOfParameterizedEntityName`, and `TypeOfMixinPseudoType`, which are placeholders, not real types.
Add checking that a type only satisfies a constraint if it satisfies all of that constraint's equality and rewrite constraints.
Enforce the rule that `=` must be used in impls when specifying associated constant values rather than `==`.
Turn off the pre-#2173 single-step equality behavior. This is getting somewhat ahead of the approved design, but it's a one-line change to restore the old behavior.
Fix `CARBON_CHECK` to handle top-level `,`s in its argument, such as may happen in template argument lists, as this change introduces such a check.
There are lots of ways a declaration can be used before we have the information necessary to handle that use. Issue diagnostics for these.
Interleave declaration and type-checking of global declarations so that declaring a later declaration can depend on the results of type-checking an earlier one.
Incorporates tests added in #2266.
Fixes#1394, fixes#1395, fixes#1396.
Co-authored-by: pmqtt <51272730+pmqtt@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This change left a test broken and removed a fair amount of test coverage for unrelated features, and after further discussion it's not clear that this is the direction we want to go in.
This reverts commit 6cf2272bbe.
Implements basic support for rewrite constraints as proposed in #2173.
Support for associated constants and complex constraints in general is also made more robust: argument deduction now properly computes and substitutes witnesses, and interface declarations track a more correct description of the constraint that they introduce than the one we previously built.
Change explorer's handling of witnesses to track them wherever possible. Associated constant support needs witnesses to be available much more pervasively.
The main changes here are:
- `Substitute` now takes a set of bindings covering both `Value`s for `GenericBinding`s and `Witness`es for `ImplBinding`s, and substitutes both.
- Witnesses are now tracked within `ConstraintType`s. The `.Self` type has an `ImplBinding` that self-references from parts of the constraint to other parts of the constraint can use to access the witness for the constraint.
- The constraint type for an `impl` and for a `GenericBinding` are now stored in pre-substituted form, with references to the actual constrained type rather than symbolic references to `.Self`. This results in minor changes in diagnostic text.
Argument deduction still performs substitutions without remapping witnesses.
Instead of forming a `SymbolicWitness` that contains an `Expression` when we can't directly resolve a witness to an `impl`, form different kinds of `Witness` values for the various situations:
- A `BindingWitness` witnesses that a type implements a constraint by reference to an `ImplBinding`.
- A `ConstraintWitness` witnesses that a type implements a constraint by reference to witnesses for each of the impl constraints within the constraint.
- A `ConstraintImplWitness` witnesses that a type implements a constraint by reference to a larger constraint which contains that constraint as an impl constraint.
Remove `SymbolicWitness` values and `InstantiateImpl` expressions, which are now unused. In order to remove the final usage of `SymbolicWitness`, I fixed a TODO to give `Self` the proper type within an interface declaration. I don't think this is an observable change.
No functional change intended.
Previously we used an expression in some places and a `Witness` values in others. The eventual goal is to make `Witness` values behave like other symbolic values such as `NominalClassType`, but the first step is to consistently treat them like values rather than expressions.
No functionality change intended.
* Multiplication and division have the same priority.
* A new builtin interface DivWith is added.
* In some tests expecting a compilation error (syntax error), the error
message now says it is expecting SLASH or binary *.
Jon Ross-PerkinsandRichard Smith
Amr Hesham
Adrien Leravat
josh11b
Junhee Cho