Note this makes some structural choices that I'm not sure how popular they'll be... Most notably, I could remove `DeclarationKind` because I'm using `std::visit` and `Declaration::Visitor` in reality. I could go to `switch(tag())` instead, but I'm wondering if this approach will be well received for the separation of ownership. Alternatively, I could move `Declaration` around so that it actually implements the things like `TopLevel` -- I did feel weird with the old structure of typecheck.cpp implementing members of declaration.h, though.
We will eventually need the ability to materialize temporaries eventually, but we don't really seem to need it yet, and when we do, I think we should do it in a way that gives uniform treatment to temporaries and local variables.
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.
This ensures that the factory functions correspond 1:1 with expression kinds, and MakeOp covers their use cases with minimal syntactic overhead now that it can take initializer list arguments.
* moved most of logic from HandleValue into the Step functions
* removed the HandleValue function
* added some comments
* responses to Geoffrey
* move increment of act->pos out of the step logic for value actions
* changed act->pos to start at 0 and not have any gaps
* Update executable_semantics/interpreter/action.h
Co-authored-by: Geoff Romer <gromer@google.com>
* update comment based on Geoffrey's suggestion
Co-authored-by: Geoff Romer <gromer@google.com>
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>
In practice, this means that `executable_semantics` will be built and run using the configuration specified on the command line, rather than e.g. always using `-c opt`.
Also fix a bug exposed by this change.
Going through tests, funptr1.6c is the main spot I see a real change, I added parens to get around an issue parsing fnty.
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 `!!`.
* more tests of tuples, especially mixing positional and explicit field names
* test of match with nested tuple
* Update executable_semantics/testdata/fun_named_params2.6c
Co-authored-by: Geoff Romer <gromer@google.com>
Co-authored-by: Geoff Romer <gromer@google.com>
* 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>
Adds all the necessary machinery to our toolchain and Bazel
configuration to support ASan. This includes ensuring sufficient debug
information is available for backtraces, etc.
As part of ASan, it enables UBSan to catch more basic undefined behavior
in C++. It also enables more complete checking in ASan for lifetime
bugs.
These configs can be enabled in any build mode with `--config=asan`.
They are also enabled by default in `-c fastbuild` where asserts are
also enabled. The goal is to have a single build mode that catches the
overwhelming majority of correctness issues.
Leak checking is part of ASan and finds leaks in `executable_semantics`
code that probably aren't interesting to fix right now. I've disabled
leak checking in the `BUILD` file for the test that showed this --
everything else passed. If more things need this disabled, the same
`BUILD` change should be easily replicated.
If you see unsymbolized backtraces, you may need to either put
`llvm-symbolizer` on your path, or point the `ASAN_SYMBOLIZER_PATH`
environment variable at it. For example, in the project root you could
do something like the following to use the downloaded toolchain's
symbolizer:
```bash export
ASAN_SYMBOLIZER_PATH=$PWD/bazel-clang-toolchain/bin/llvm-symbolizer
```
I'll try to update documentation soon with this as well.
- Give unary `-` and `not` the same precedence as in C++
- Add detail to parse error messages, and make the --trace flag also enable parser debug tracing
- Make any new shift-reduce conflicts into build errors
- Use `%precedence` rather than `%nonassoc` where possible, in order to catch more grammar bugs at build time
Geoff RomerandJon Meow
Jeremy G. SiekandGeoff Romer
Richard SmithandGeoff Romer
Richard Smith
Chandler Carruth