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>
The intent here is that changes to prelude.carbon shouldn't break every test that expects some error from prelude.carbon; that would be too fragile. As a consequence, this effectively ignores the line number in prelude.carbon.
This is a little complex because we don't know which line in the original source file is actually causing the error, just that there is an error. Also, the previous look-behind approach required a fixed-with prefix, whereas we want a little more than that in order to capture the filename for comparison.
This would be hard to do with extra_check_replacement because the path to bazel.runfiles is complex to calculate. As a consequence, this is basically all new code.
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>
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.
Allow explicit conversion from a tuple of `T1`, `T2`, ... to a tuple of `U1`, `U2`, ... if each element has an explicit conversion.
Also add a comment to existing `ImplicitAs` impl for tuples explaining its purpose.
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.
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
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`
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`
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>
Makes explorer/testdata/assoc_const/rewrite_large_type.carbon NOAUTOUPDATE and no-trace because otherwise it takes ~130s to run. With this it's sub-second, explorer is just dumping a lot of trace output (maybe still something to fix).
This adds a second double linked list test carbon program, which has
the major difference, that it is not bound to a type but rather uses the
generics system to allow the type to be be specified at creation.
Of course this is heavily inspired by the first linked_list example program,
but this does show of/test a different feature set solving the same problem.
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.
Within the type of an associated constant, references to `.Self` should resolve symbolically to that associated constant as a `GenericBinding` so that it can be substituted for the actual value when using its type. However, when the associated constant is referenced from elsewhere in the same interface, the value we want is a symbolic value naming the constant as a member of `Self`.
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.
* fix issue-1392
* run pre-commit
* run pre-commit
* Update explorer/interpreter/type_checker.cpp
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
* change test file
* change test file
* remove size check
* Update explorer/interpreter/type_checker.cpp
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: m new <michael.burzan@outlook.de>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Instead of checking and resolving rewrites eagerly, defer doing so until a constraint is applied to a binding. Actual resolution of rewrites is not yet implemented, so this is mostly just refactoring, but the eventual goal is to support things like `(Constraint where .T = .U) & (Constraint where .U = V)` (however they are reached) by applying one rewrite to the other, as agreed with @josh11b in discussion of #2173.
One nice consequence is that substitution into a constraint type no longer has a failure path, so substitution is once again not able to fail.
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.
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.
Richard Smith
Jon Ross-PerkinsandRichard Smith
Amr Hesham
Adrien Leravat
Carson Radtke
Priyananda Shenoy
josh11b
Liz
