This starts detecting naming collisions as a consequence of being able to determine when the name is declared twice in a given scope.
Co-authored-by: Geoff Romer <gromer@google.com>
This lets us statically distinguish between code that works with arbitrary `Address`es and code that can only work with pointers to separately-allocated storage, and so we no longer need to worry about the latter code crashing at run-time (as `Heap::Deallocate` did) or silently doing the wrong thing (as `Heap::PrintAddress` did) if it's given the wrong kind of `Address`.
Rationale: Based on the status of #478 and #505, Carbon won't have this feature for a while, and it will be simpler not to support it on spec in the meantime.
Prior to this change, `__await` would make a deep copy of the continuation stack, but shallow-copy the individual stack frames within it. As a result, continuations appeared to have shallow semantics so long as the continuation stack had only a single frame.
This change also removes an obsolete test from the brief period when we intended continuations to have deep-copy semantics, which has been passing basically by accident.
This does a mass rename of:
- `SourceLoc()` -> `source_loc()` for property naming
- `loc` -> `source_loc_` for underscore+consistency
- Generally changing function args to `source_loc` for consistency
- `Tag()` -> `kind()` for property naming and `Kind` parity
- `tag` -> `kind_` for underscore
Also renames `Pos` and `Results` on `Action`. These are a bit of an exception in that most base classes only have `Tag` and maybe `SourceLoc`, whereas `Action` has a little more. I felt okay having `source_loc()` and `kind()` on the base class where children do `Exp()` and the like, but it felt weird to me to mix it on the same class.
The reason for doing this cross-class in one PR is so that I can do it efficiently with a global replace in the codebase, rather than e.g. changing `Expression` but having to read through compiler errors to determine where it's calling `Expression`'s `Tag` versus a different `Tag`. The end result should be equivalent.
With this, only main.cpp instantiates an arena. Maybe we'll want to split that up more later (e.g., so that the runtime interpreter uses its own arena), but given the intent to have type-checking update the AST, I thought this was a reasonable approach for now in order to avoid ownership complexities.
Fixes#769
* Debugging quality-of-life improvements
- Use std::abort for `CHECK`/`FATAL` failures, which acts as a debugger breakpoint as well as automatically printing a stack trace.
- Re-enable printing continuations in `--trace` mode.
- Log the source location of each step in `--trace` mode.
Co-authored-by: Jon Meow <46229924+jonmeow@users.noreply.github.com>
Note this makes a few cases where the Statement was optional explicit (Block, If, Sequence). I do add a few CHECKs around where statements were optional and assumed but unverified.
I switch TypeCheckStmt to not take an optional Statement because I think it makes the call sites clearer in behavior. It's also a smaller change than the converse, because taking an optional Statement means the returned statement would also need to be optional. Arguably a wrapper for optional statements could be added, but this still seems cleaner to me, and there aren't that many cases of an optional statement.
Co-authored-by: Geoff Romer <gromer@google.com>
It was in my mind to add String in order to support libraries in `package`. `print` is added in order to have a String go to stdout. I've tried to do `print` in a way that won't be too hard to add other printable types, but it's probably also somewhat optional here -- that is, if desired, I could remove it. But it was a lot easier to doublecheck `\n` behavior with it, and I suspect it'll be helpful in other tests if it supports more value types.
On the side, this also fixes dereferencing in Pattern/Expression Print() calls, which I was noticing printing pointers instead of values. This may be another argument for moving away from passing pointers, since this seems to be a difficult-to-catch error.
Co-authored-by: Geoff Romer <gromer@google.com>
This is intended to:
- Standardize use of line_num (and highlight where no line_num is available).
- Standardize indications of runtime/compilation errors.
- Make it incrementally easier to write new errors.
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
I was looking for something like this, I think it's a straightforward simplification for code. Internally, it handles skipping the separator on the first print.
See the bottom of: https://llvm.org/doxygen/StringExtras_8h_source.html
- Switch code to llvm::raw_ostream as part of standardizing output forms.
- Preferring llvm::raw_ostream over std::ostream because other tooling code should be expected to rely on llvm more closely, and an overall preference towards library consistency.
- There are a couple spots in syntax/ that still use std streams, but I'd prefer to take a separate PR to see how best to address those.
- std::boolalpha doesn't work with llvm, so I've implemented equivalent in a couple places (not enough that it felt like worth making a helper function).
- Implement Print(ostream) as consistently as we can, as an instance member.
- This facilitates the use of the common/ostream.h template to provide operators.
- Preferring this approach so that Print is easily accessible via gdb, per suggestion on #executable-semantics.
- Switch code currently calling `type->Print(ostream)` to instead do `ostream << *type`.
- Remove the unused `PrintTypeEnv`, nothing used it and the declaration didn't match the definition.
- Move Heap and Frame/Scope to their own headers.
- Move some functions to more appropriate headers (e.g. CopyValue -> value.h).
- Define a separate Bazel rule for each header/cpp pair.
- Modify PrintValue to not print the frames of a ContinuationValue. This was necessary to break a dependency cycle between PrintValue, PrintFrame, and Action::Print.
Co-authored-by: Jon Meow <46229924+jonmeow@users.noreply.github.com>
Also:
- Switch data members, and associated parameters and return types to be values/references rather than pointers, where applicable.
- Move Expression's TagVisitor to anonymous namespace, to avoid name collision.
- Switch to trailing return syntax (per style guide).
Pretty much any names will be awkward, since these types represent cases where an `Expression` is not an expression, and a `Value` is not a value, but we can at least be more explicit about the fact that they represent bindings rather than variable usages.
- `Kind` enumerator names always match the corresponding factory function, accessor, and type names (if any).
- All abbreviations in those names are expanded.
- Those names always have a suffix to disambiguate expressions from values.
`VarTV` is excluded from these changes because there's a pending PR to remove it.
The presence or absence of whitespace is used to determine which
operator is in use, following the rules described in #520.
Support for prefix * dereference operator follows #523.
Co-authored-by: Geoff Romer <gromer@google.com>
* changed union of Statement to be private
* changed the union in Expression to be private
* changed union in Value to be private
* changed AST constructors to be static methods
* updates to syntax unit tests
Additional miscellaneous cleanup:
- Use the term "deallocate" instead of "kill" in function names, for symmetry with "allocate".
- Drop an unnecessary memory allocation in `AllocateValue`.
- Implement `PrintHeap` in terms of `PrintAddress`, so that dead values are flagged with `!!`.
* fix tuple equality, added test cases
* added a comment to an old function
* Update executable_semantics/interpreter/value.cpp
Co-authored-by: Geoff Romer <gromer@google.com>
* fix error in Geoffrey's edit
Co-authored-by: Geoff Romer <gromer@google.com>
* improved checking for liveness when reading and writing memory
* moving some functions to be methods of State
* finished moving functions into State
* Update executable_semantics/interpreter/interpreter.h
Co-authored-by: Geoff Romer <gromer@google.com>
* moved some comments, other minor edits
Co-authored-by: Geoff Romer <gromer@google.com>
Geoff Romer
Jon MeowandGeoff Romer
Jeremy G. SiekandJon Meow
Richard SmithandGeoff Romer