This adds a distinction between Unused and SoloParseNode, rather than
equating the two. This is intended to help identify nodes which are
getting pushed but maybe don't need to be.
Not totally done because I want to adjust declaration name handling due
to a quirk with how it mixes Name with Expression, but almost done. Once
that's done the type punning will be completely gone.
I think there's more we can do here, but this seemed like a good
checkpoint to make sure the path I'm going down is roughly what you
expected. There's one actual edit in if expression structure to match
the increased enforcement.
This handles namespacing of functions. Parsing and semantics are changed
significantly, while lowering works without changes. Variables can't be
namespaced yet because they're dealing with patterns, and I didn't dig
through that code.
Most of the logic is done through the new name declaration stack, which
is necessary because semantics isn't quite sure where the declaration
name ends. It'd be complex for parsing to send a signal about this,
probably involving node variants and rewrites of the tree, and this
solution seems to work well. Unfortunately this means a new stack, but
that may be inevitable due to the extra information needing to be
tracked.
Note this doesn't deal with scoped lookups of non-namespace things,
which we'll need for generics. That'll probably involve pushing resolved
scopes onto a stack (or maybe just setting a singleton value?) to affect
contextual name lookup. But, I think the basics are there to make it
work when we can test the behavior.
This renames "designator expression" to "qualified expression" and adds
"qualified declaration" in order to use terminology more consistent with
C++.
Namespaces will probably need to be considered for name mangling down
the line, but this still uses the basic name.
This PR renames parse nodes on a Name/NameExpression taxonomy. NameExpressions occur in a name context. The difference is that in non-expression contexts it's useful to return the identifier / string ID for adding to name lookup, whereas in expression contexts it's useful to return the resolved node ID for consistency with other expressions.
In the code, I do note SelfValueName is returned in the expression context: I'd expect this to change, as `self` in `[self: Self]` versus `self.Foo()` will probably be best handled similarly to the above. That means that, in the proposed taxonomy, both `SelfValueName` and `SelfValueNameExpression` will exist in order to assist semantics.
To contrast choices:
Original | Current | [zygoloid suggestion](https://discord.com/channels/655572317891461132/655578254970716160/1121581663399464970) | [This PR](https://discord.com/channels/655572317891461132/655578254970716160/1121814551789318215)
--- | --- | --- | ---
DeclaredName/DesignatedName | Identifier | NameComponent | Name
NameReference | NameReference | NameReference | NameExpression
SelfValueIdentifier | SelfValueIdentifier | SelfValueReference | SelfValueName
SelfTypeIdentifier | SelfTypeIdentiifer | SelfTypeReference | SelfTypeNameExpression
This shifts logic so that bindings are added to name lookup only after the scope is complete, removing logic around adding/removing/re-adding names in certain scopes.
This does mean that things like a function's forward declaration will need to go through an extra hoop for name conflict checks, because under this approach a function definition does conflict checking when it adds names for the body's use. But, that seems easy to address, and better than the current hoops.
I'm looking at adding CallableId, so figured I'd do this API refactoring which should reduce code duplication. This increases the amount of cross-calls between APIs because it may not be an issue for performance after optimizations, and should simplify reading of the API.
Also note the prior static_asserts on layout were missing a couple types, which is why I'm moving them into Entry where it's going to be more obvious when something's added.
This is a rename of a commonly used accessor. I tend to prefer shorter names, but it's semantics_ir in LoweringContext, and it feels odder to shorten to semantics there than to lengthen to semantics_ir here. I already have builtins_ir around here, too. I think it's helpful to use consistent names for semantics_ir since they're dealing with essentially the same thing.
Previously, IR for arguments in calls and struct values was separated out. This merges it back in. Additionally, parameters for functions and struct types had their own IR; the block is still there, but there's a TODO to decide what to do with it.
In the LLVM IR, this has the consequence of emitting expressions that are inputs to a call or struct value within the scope of the function, which is pretty much where it should be. Importantly it happens before the call is encountered.
This change also tinkers with the int and real literal lowering. I'm pretty sure both are still wrong, but was having trouble figuring out a "better" way to do it, and this seems like it'll work for now.
This echoes #2818 and the philosophy is mostly covered there.
Versus parsing, semantics uses fewer separate handler files (for now) because the logic has been shorter. However, the design is still intended to make it easy to split files along boundaries similar to the parser, as I've done for a couple more complex/inter-related sections.
Jon Ross-Perkins
Richard Smith