I've been mulling this mainly for the parameter complexity of
check/lower, but doing lex/parse for symmetry.
I'm motivated by the plan to move dumping for all of them into the
respective functions, because of discussion about llvm-verifier. That
basically would add another bool parameter (or more) to each of these.
My instinct is we're going to probably accrue a little more over time,
so I'm suggesting this as maybe adding the boundary a little simpler
and/or easier to read.
Note it may make sense to refactor a little further, e.g. maybe
Lower::Context could receive the full set of options and pick out what
it wants, but I figured creating the struct itself would be a decent
start.
I'm trying to put things into options when we can produce a reasonable
default if the user doesn't assign a value. I'm using an explicit
constructor so that values can be added without affecting every caller.
A different factoring would be to pass in everything through the param
struct, but that just felt weird when I was trying it out.
Removing `inst_namer` and `module_name` from `LowerToLLVM` params --
both of these can be inferred from `sem_ir`, and I'm not seeing a
particular reason to maintain them at the call site.
Removes the nullptr default for safety.
Note, I think cpp support doesn't allow things like `<version>` or
inline code yet, and language-server support doesn't allow non-hermetic
files, so the best I can test is an error.
This requires:
* Making `FunctionDecl` mutable since generating code
(`HandleTopLevelDecl()`) requires a mutable declaration and since we
manually add `used` attribute to force code generation.
* Passing the file system to `Lower` since it's needed by Clang code
generation.
* Creating an internal Clang LLVM module and link it against the Carbon
LLVM module.
Demo:
```c++
// hello_world.h
extern int puts;
inline void hello_world() {
((int (*)(const char*))&puts)("hello world");
}
```
```carbon
// main.carbon
library "Main";
import Cpp library "hello_world.h";
fn Run() -> i32 {
Cpp.hello_world();
return 0;
}
```
```shell
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link main.o --output=demo
$ ./demo
hello world
```
Based on https://github.com/carbon-language/carbon-lang/pull/5406.
Part of #5405.
Right now we construct `tree_and_subtrees_getters` a couple different
ways, it's just not obvious because one's abstracted in `check`. But
also, when formatting IR, we'll repeatedly do the `IncludeInDumps`
string check, which felt odd to me since it only needs to be calculated
once per IR.
This also shifts `CheckIRId` selection a little earlier, and in doing so
makes `CheckParseTrees` accept a sparse `units` argument. I actually
think this is a positive: it makes `CheckIRId` a little more stable
across possible command lines, when file loading fails (which is the
only time that a file will have a `CompilationUnit` but not a
`Check::Unit`).
Trying to build on the shared issue between these, I'm adding a
`MultiUnitCache` to store the calculated arrays. For the subtree
getters, this is very minor and avoids at most one incremental array
construction (moving logic out of `CompileSubcommand::Run` might be the
bigger benefit). For `include_in_dumps`, when dumping SemIR, this is
changing a calculation run once per entity (in each IR) to be calculated
once per IR (globally), i.e. O(M*N) -> O(N).
Note this seems to be marginal for performance of file_test:
- Before: Stats over 10 runs: max = 5.3s, min = 4.7s, avg = 4.9s, dev =
0.2s
- After: Stats over 10 runs: max = 4.9s, min = 4.7s, avg = 4.8s, dev =
0.1s
I was mainly thinking about this in the context of dumping SemIR ranges.
There, the impact may actually decrease because a range won't do any
cross-IR printing. But, I'm expecting to add another layer for whether
we're printing IR for a file, and that made the `should_format_entity`
callback stick out for me.
Given the namespacing of `Diagnostics` in #5173, now we can use
`DiagnosticEmitter` for phase-specific emitters. This is consistent with
how we do `Context`, and also check had started this with
`DiagnosticBuilder` in anticipation of the namespacing.
Also renames `Emitter::DiagnosticBuilder` to `Emitter::Builder` for
consistency with other `Diagnostics` entities.
In check, I'm still splitting `DiagnosticEmitterBase` and
`DiagnosticEmitter` just to keep the emitter definition separate from
the context.
Also cleans up some incorrect check diagnostic emitter dependencies in
lower.
What this really does is avoids shadowing names, so that we can
comfortable have things like `Check::DiagnosticEmitter` or
`Check::DiagnosticLoc` without shadowing being a concern.
Note, down this path I'm also thinking about:
- Renaming misc DiagnosticConsumer/DiagnosticEmitter classes, possibly
just to DiagnosticConsumer/DiagnosticEmitter (so
`Check::DiagnosticEmitter` instead of `SemIRLocDiagnosticEmitter`).
- Dropping `Diagnostic` from `Emitter::DiagnosticBuilder`.
- But not for `Check::DiagnosticBuilder`, because `Check::Builder` would
be ambiguous.
- Renaming diagnostics/diagnostic_* to drop "diagnostic".
[Discussion about SemIRLoc ->
DiagnosticLoc](https://discord.com/channels/655572317891461132/655578254970716160/1353771570463768698)
reminded me of this (in particular the older [Check::DiagnosticBuilder
discussion](https://discord.com/channels/655572317891461132/655578254970716160/1344363562608627763)),
but I'd only do that rename if there's matching consensus about a path
forward where we keep SemIRLoc, and in a way that it's only ever used
for diagnostics (the divergence from which is at the root of current
LocId discussion).
I'm trying to keep that separate from a namespace addition for clarity.
Without this, diagnostics will linger after closing a file.
This refactors towards a pattern of putting outgoing calls as methods on
`Context`. I'm mixed on this, mainly thinking it's an improvement on
using `outgoing` directly (because it shares the name and structure),
might want to move it to a side-class later that is _only_ LSP wrappers.
I could also make inheritance private on OutgoingMessages and these
kinds of methods public there, but I'm hesitant to adopt that approach
versus a type separation.
Add caching of parsed documents, and testing of the textDocument
handlers. This is based on #4896, which splits out some of the
boilerplate to calls.
Note, this caches the entire parse state because we'll want to try to
emit diagnostics when we see the update, without waiting. It may be
helpful to do that asynchronously, but we don't want to wait for another
call (such as documentSymbol). Really, we'll probably want to also add
check for diagnostics, at least.