Building on #4411, avoid using StringLiteral in format strings. This
includes a diagnostic check to prevent regressions (which is also how I
gathered issues).
Note, I haven't looked at `std::string` uses yet, but we might need
things like that to be able to pass strings in code back to the user.
StringLiteral though means that it's literally written down in the
toolchain, at which point it should probably be written in the format
string instead of separately.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
Includes support for the `impls`, `=`, and `==` requirement operators to
the right of a `where`, but `and` to allow multiple requirements is
still a TODO.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Playing with the macro suggestion on #4028, replace DeclKind with some
templating that asserts the in-use token is an introducer token. This
allows type-safe usage of Lex::TokenKind, reducing the benefit of a
separate enum while improving stdout (since now this will ostream as the
keyword name).
This provides `export import` logic in lex, parse, and check; `export
name` logic is only in lex and parse, not check.
I think with `export name` I'm going to need to modify import_ref and
some consolidation logic, whereas `export import` seems feasible to keep
as primarily import logic. Given the implementations were looking like
they'd diverge more substantially, I thought it'd be helpful to cut the
PR here.
This doesn't add full support. I'm separating it out to make the effects
of the modifier changes clearer for review. I'm restructuring a little
with the expectation that we'll have some more categories of modifier
keywords in the future (similar to `extern`, these may not be in a "set"
such as access), and thus easily scaling up to a few more would be
useful.
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.
When originally switching to the table dispatch approach we discussed
that it'd be nice to disentangle the monolithic symbol lexing routine
with this as we'll typically have fairly precise dispatch. This is
especially true for grouping symbols, which in Carbon are all
constructively one-character (at this point).
I think this provides a substantial improvement to the clarity of the
code by disentangling the different paths. It also allowed a bunch of
simplifications / clarifications to exactly what the behavior with
closing invalid groups actually involves currently.
This was initially motivated by code organization improvements, and any
performance wins were speculative. However, when benchmarking it
surfaced a problem that hadn't been clear -- we're generating too many
distinct functions here, and the table-based dispatch slows down in the
face of that.
So this PR also includes a fix for that, removing the template-generated
fan-out of dispatch functions for distinct symbols. Instead, we have
a dedicated table to translate one character into the token kinds. This
seems to work quite well, avoiding the huge branch-y structure and just
do fairly cheap table translation & dispatch for all one-character
symbols. Building the table requires the token kinds to be default
constructable, so this also enables that and arranges for the zero-value
kind to be the error kind.
Combined, this is a modest speedup for *non* grouping symbols (3-4%,
a bit noisy). And in some cases it is a huge speedup for grouping
symbols (>10%).
Raw benchmark data with 20 runs before/after -- despite the # of runs,
the grouping symbols benchmarks were frustratingly noisy in non-uniform
ways that couldn't fully be accounted for here. Still, this seems like
an overall improvement.
```
BM_RandomSource 7.98ms ± 2% 7.73ms ± 3% -3.12% (p=0.000 n=18+19)
BM_GroupingSymbols/1/0/0 5.90ms ± 2% 5.82ms ± 4% -1.38% (p=0.001 n=20+20)
BM_GroupingSymbols/2/0/0 5.21ms ± 2% 5.15ms ± 2% -1.14% (p=0.002 n=20+18)
BM_GroupingSymbols/3/0/0 4.42ms ± 2% 4.34ms ± 2% -1.87% (p=0.000 n=19+18)
BM_GroupingSymbols/4/0/0 4.29ms ± 2% 4.38ms ± 5% ~ (p=0.297 n=17+20)
BM_GroupingSymbols/8/0/0 5.09ms ±10% 5.10ms ± 7% ~ (p=0.919 n=18+20)
BM_GroupingSymbols/16/0/0 6.35ms ± 8% 6.29ms ± 6% ~ (p=0.201 n=20+20)
BM_GroupingSymbols/32/0/0 9.88ms ± 2% 9.83ms ± 1% ~ (p=0.167 n=18+20)
BM_GroupingSymbols/0/1/0 5.12ms ± 2% 5.01ms ± 2% -2.14% (p=0.000 n=20+19)
BM_GroupingSymbols/0/2/0 4.01ms ± 2% 3.93ms ± 4% -2.03% (p=0.000 n=20+19)
BM_GroupingSymbols/0/3/0 2.92ms ± 3% 2.81ms ± 2% -3.87% (p=0.000 n=20+19)
BM_GroupingSymbols/0/4/0 2.61ms ± 3% 2.47ms ± 2% -5.30% (p=0.000 n=20+18)
BM_GroupingSymbols/0/8/0 1.77ms ± 3% 1.61ms ± 2% -8.91% (p=0.000 n=18+19)
BM_GroupingSymbols/0/16/0 1.41ms ± 3% 1.16ms ± 4% -17.66% (p=0.000 n=20+20)
BM_GroupingSymbols/0/32/0 1.10ms ± 2% 0.92ms ± 3% -16.36% (p=0.000 n=20+17)
BM_GroupingSymbols/0/0/1 5.09ms ± 2% 5.03ms ± 3% -1.11% (p=0.001 n=20+18)
BM_GroupingSymbols/0/0/2 4.01ms ± 2% 3.91ms ± 2% -2.67% (p=0.000 n=20+18)
BM_GroupingSymbols/0/0/3 2.93ms ± 3% 2.81ms ± 2% -4.23% (p=0.000 n=20+19)
BM_GroupingSymbols/0/0/4 2.59ms ± 2% 2.48ms ± 3% -4.48% (p=0.000 n=20+19)
BM_GroupingSymbols/0/0/8 1.75ms ± 1% 1.62ms ± 3% -7.65% (p=0.000 n=17+19)
BM_GroupingSymbols/0/0/16 1.40ms ± 2% 1.15ms ± 3% -17.67% (p=0.000 n=19+20)
BM_GroupingSymbols/0/0/32 1.10ms ± 2% 0.92ms ± 3% -15.91% (p=0.000 n=20+19)
BM_GroupingSymbols/32/1/0 9.62ms ± 2% 9.65ms ± 2% ~ (p=0.654 n=18+20)
BM_GroupingSymbols/32/2/0 9.41ms ± 2% 9.37ms ± 2% ~ (p=0.095 n=20+19)
BM_GroupingSymbols/32/3/0 9.13ms ± 2% 9.13ms ± 3% ~ (p=0.687 n=19+20)
BM_GroupingSymbols/32/4/0 8.93ms ± 1% 8.87ms ± 2% -0.69% (p=0.010 n=20+18)
BM_GroupingSymbols/32/8/0 8.15ms ± 2% 8.14ms ± 3% ~ (p=0.729 n=19+19)
BM_GroupingSymbols/32/16/0 7.04ms ± 3% 6.92ms ± 1% -1.71% (p=0.000 n=20+18)
BM_GroupingSymbols/32/32/0 5.48ms ± 2% 5.38ms ± 3% -1.81% (p=0.000 n=20+20)
BM_GroupingSymbols/32/32/1 5.39ms ± 2% 5.29ms ± 2% -1.87% (p=0.000 n=19+19)
BM_GroupingSymbols/32/32/2 5.34ms ± 2% 5.21ms ± 1% -2.45% (p=0.000 n=20+18)
BM_GroupingSymbols/32/32/3 5.27ms ± 3% 5.16ms ± 2% -2.18% (p=0.000 n=20+19)
BM_GroupingSymbols/32/32/4 5.21ms ± 2% 5.10ms ± 3% -2.11% (p=0.000 n=19+20)
BM_GroupingSymbols/32/32/8 4.98ms ± 2% 4.83ms ± 2% -2.85% (p=0.000 n=19+19)
BM_GroupingSymbols/32/32/16 4.55ms ± 2% 4.45ms ± 2% -2.25% (p=0.000 n=18+20)
BM_GroupingSymbols/32/32/32 3.95ms ± 2% 3.84ms ± 2% -2.98% (p=0.000 n=19+20)
```
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.
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>
Jon Ross-PerkinsandGeoff Romer
Chandler Carruth