It turns out we can make these work with very minimal complexity because
the LF is still in the right place either way. This also lets us easily
support mixtures of LF and CR+LF line endings gracefully. We create the
line structures around the LF bytes and then have the byte-dispatch loop
notice a CR followed by an LF and skip to the LF behavior.
Rather than add the remaining complexity around supporting bare CR and
LF+CR sequences (both of which are quite rare now), this just adds
diagnostics when we encounter a CR byte that won't fall out of our CR+LF
handling. This is a better experience for users than the alternative. We
still have a TODO to handle the full complexity of vertical whitespace,
but I've updated it to reflect that the common case should be handled
already.
This isn't complete though: we need to add support in string literal
lexing, and we need to teach the diagnostic rendering to handle the
error messages above better. But those will be future PRs, this is
enough to unblock folks who happen to edit a Carbon source file with
notepad on Windows which seems important.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
`i32` is retained as a special case for now, for bootstrapping purposes,
and maps to `BuiltinIntType`, which is distinct from `Core.Int(32)`.
This will be removed later once we support `Core.BigInt`.
For now this provides both the `iN` types and also the builtins to
support `Core.Int(N)`. The intent is that we'll change the `iN` support
to rewrite to calls here when we do that for the other type literals and
type keywords.
No conversions between integer types are supported yet, and all literals
are of type `i32`, so we can't actually form values of any of these new
types.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
On #3792 it was requested to put context-related diagnostic messages
prior to the diagnostic error. In order to support that, remove the
distinction that an error needs to come first on DiagnosticMessage.
Similar to #3705, we actually have a mix of `Make` and `Create` in
factory functions too, so this PR is normalizing on `Make`. It's
intended to be consistent with the naming choice for Carbon factory
functions.
Note, MakeSyntheticBlock is the only one I feel a little weird about
because llvm's own APIs use Create, and this is essentially wrapping
LLVM calls. But the flipside is it also feels like a vague line to draw,
when we also differ from LLVM coding style in other ways.
Move handling of mismatched brackets out of the main lexing loop into a
separate pass that is only run if there are mismatched brackets This is
done in preparation for using both lookahead and lookbehind to work out
how to match brackets, and to get this code far away from the hot lexing
loop.
Fix bracket insertion location to be immediately after the token that
we're inserting the bracket after, rather than potentially at the end of
a comment. When there are open brackets at the end of the file, say that
there are open brackets, not that there's a closing bracket without a
matching opening bracket.
I was suggesting this because `FloatingPoint` is pretty long. `int` and
`float` should be familiar abbreviations. `unsigned` should be familiar
to developers too, but `UnsignedInt` still feels usefully clearer for
the additional chars.
Following up on discussion yesterday regarding this split.
Note, I'm expecting #3341 to do IdentifierId -> NameId in SemIR. It
might be worth adding NameId creation directly to StringStore if you're
content with this setup though.
Provides an adapter for the llvm::yaml API because it otherwise needs a
bunch of const/non-const definitions, and the traits are difficult to
diagnose issues with. The current approach is pretty simple to use, even
if it's not super efficient (which, yaml output is more of a debugging
thing so I'm not really expecting it to be an issue).
Changes the format of yaml output to provide more index information,
just as reminders when seeing something like `node+0`. Note this would
create more churn in deltas if we were reliant on the output yaml in
tests, but we aren't so it should be okay.
Building on #3311, change SemIR to use the SharedValueStore. Since this
removes hermeticity, raw output no longer prints ints, reals, and
strings. TokenizedBuffer accessors are modified to return IDs because
values are often passed through in semantics without needing to read
them.
I would've put SharedValueStores on Context, except for the
GetArrayBoundValue convenience method. I felt awkward removing that, so
it's on File, at least for now. That's then used by the formatter and
Lower too. The flipside of this is that TokenizedBuffer has a
SharedValueStores only for printing, so maybe that's similar enough to
what File is doing.
This doesn't start shifting other SemIR members to ValueStore, but that
seems like a next step.
This updates lexing to use the data. I'll do checking separately, just
to split changes.
Note the ValueStore structure is also set up such that SemIR::File can
use it for other fields.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This uses the musttail dispatched table approach to drive the entire
lexing. The result is that there is no main lexer loop at all in a
traditional sense, now everything is driven through tail recursive
dispatch on the next byte of the source text.
This should be easy to extend still -- the design pattern is to add
lexer methods for handling specific cases, and then add a dispatch
function to dispatch to them from the table. For example, we can add a
method that handles decoding UTF-8 outside of the ASCII subset and set
the table entries used by non-ASCII initial bytes to dispatch to it.
The performance is already surprisingly good, benchmarks show a modest
improvement across the board. That's despite there still being some
*serious* performance issues that I'll fix in a separate patch. There
are also opportunities to leverage this structure more heavily as needed
by putting more specialized dispatch targets in for specific bytes.
A follow-up PR will re-organize the functions here, as almost all of the
methods on the `Lexer` should become private, but I wanted to keep that
a separate change since it will probably render the diff even more hard
to read than it already is.
This removes a (very) hot branch in the lexer where we need to special
case when a token is the first token and can't look at its previous
token. It also seems like a generally nice change to the structure of
both the token buffer and parse tree as there are now bracketing
elements for both ends and we should be able to avoid similar branching
in the future.
Mostly mechanical updates to the lexer and parser code to handle this,
but also needed to special case the location information in the
autoupdate code. And then the usual large body of auto-updated tests.
No benchmark data for this change alone as in isolation and in the
current lexer structure it doesn't make a big difference. But this
branch was particularly difficult to handle when trying to update the
whitespace skipping code to be faster, and so I think it is worth
systematically avoiding the special case here.
Rationale: this convention avoids forcing closely-related code to be far
apart in the namespace hierarchy, and vice versa. By the same token, it
makes the namespace hierarchy more consistent with the directory
hierarchy.
Previous code could fail silently, only caught with yaml output
mismatches. This uses ErrorOr to be explicit about the error detection;
recovery isn't supported because we should only print valid yaml (in
tests, at least).
Also moves the test helpers from //toolchain/base to
//toolchain/testing.
Switches tree_test to use the matchers so that, on mismatch, gtest
prints a path to the mismatch (the straight value means it was just
printing "not equal").
Addresses
https://github.com/carbon-language/carbon-lang/pull/3217#discussion_r1323586836
Lex now prints its yaml as:
```
- filename: name
tokens: [ ... ]
```
New support in file_test allows the `filename` marker at the top to
define the default file number for later lines, meaning multi-file
output from lexing is now associated with the appropriate file. Similar
support will probably also apply to lowering, semir, and other places
that print a filename once for the full dump.
This hammers a bit at how line number replacements work in file_test,
allowing stacking them so that lex errors and stdout can both be
line-associated properly. I've tried to make the autoupdate more
frequently work in one pass, now also taking into account the file index
when doing line replacements.
There are still some issues with EndOfFile that it may be good to
discuss: because CHECK lines are appended to the end of the file now,
and the EndOfFile token points at the last line including comments, new
lex tests now take two runs to autoupdate (because without CHECK lines,
the EndOfFile points at a content line, which content is then inserted
after). Note that removing CHECK lines from the test is not a solution:
autoupdate also started inserting blank lines, which breaks this for a
similar reason. One solution here might be to not have EndOfFile
associate with a line or column, which has been a bit of an issue
regardless.
Also fixes a small issue with toolchain's autoupdate script.
This updates SourceBuffer to diagnostics. Some additional edits to
diagnostics were necessary due to issues moving arguments around, which
seems to stem from a compile error with clang 14 (fixed in later
versions).
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Rearranges driver logic into CompilationUnits in order to associate
artifacts from the various stages of compilation.
Note, I'm not totally sure what the right thing to do is for
lower/codegen, so I'm just doing a rote change there for now that
mirrors prior phases (this is all the code supports anyways, so is
probably right for now regardless).
SourceBuffer error output is moved local for consistency with other
steps, and so that it's less ambiguous whether the error should be
expected to already include a filename.
Continuing with #3070. Just a dir and file rename (only prefix change is
lexer_file_test). Everything in the lex dir should be marked as a move.
Note, I think this closes#3070. There may still be further cleanup
later, but the organizational changes suggested there are being
completed.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Chandler CarruthandRichard Smith
Jon Ross-Perkins
Geoff Romer