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.
This switches most error printing to use diagnostics instead of direct
stream writes, even when not a specific file diagnostic. I'm allowing
empty filenames for this use-case.
This allows a little more specific testing to validate coverage of
output using the diagnostic coverage test. I'm adding a few tests to
cover things that weren't previously tested.
Separately, this also forces a little more standardization in format...
considering how changes like #4568 show effort being spent to _mirror_
diagnostic style, my thought is now to just use diagnostic code where
possible.
Note this also allows incrementally better testing of the language
server; I'm changing the crash fix from #4847 in favor of diagnostic
testing.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Mainly, changes the default from -1 to 0 in DiagnosticLoc, still trying
to keep reusing that. Nothing except for the lowered output is affected,
so I think this is fine.
Also, have lowering consistently call GetDiagnosticLoc.
Pulls in one of the CHECKs suggested from #4251
Co-authored-by: David Blaikie <dblaikie@gmail.com>
I'm trying to make the line of code more clearly nested in crash output
(the way it is, I sometimes forget about it). Also,
`Check::HandleFunctionDecl` is the old naming scheme, it's now all
`Check::HandleParseNode`, so I'm replacing that.
Before:
```
3. extern_library_owner.carbon:6:1: Check::HandleFunctionDecl
extern fn F();
^~~~~~~~~~~~~~
#0 0x0000564c0057ef1d llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) ...
```
After:
```
3. extern_library_owner.carbon:6:1: checking FunctionDecl
extern fn F();
^~~~~~~~~~~~~~
#0 0x00005629029ffd9d llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) ...
```
When we crash, include the source location of the parse node that we
were handling, as well as the name of the check function that we were
calling. Also include the source snippet, since it's easy to do so, and
may avoid the need to look at the input file in some cases.
Jon Ross-Perkins
josh11bandJosh L
Richard Smith