fixes#16376
The way the compiler handled generic proc instantiations in calls (like
`foo[int](...)`) up to this point was to instantiate `foo[int]`, create
a symbol for the instantiated proc (or a symchoice for multiple procs
excluding ones with mismatching generic param counts), then perform
overload resolution on this symbol/symchoice. The exception to this was
when the called symbol was already a symchoice node, in which case it
wasn't instantiated and overloading was called directly ([these
lines](b7b1313d21/compiler/semexprs.nim (L3366-L3371))).
This has several problems:
* Templates and macros can't create instantiated symbols, so they
couldn't participate in overloaded explicit generic instantiations,
causing the issue #16376.
* Every single proc that can be instantiated with the given generic
params is fully instantiated including the body. #9997 is about this but
isn't fixed here since the instantiation isn't in a call.
The way overload resolution handles explicit instantiations by itself is
also buggy:
* It doesn't check constraints.
* It allows only partially providing the generic parameters, which makes
sense for implicit generics, but can cause ambiguity in overloading.
Here is how this PR deals with these problems:
* Overload resolution now always handles explicit generic instantiations
in calls, in `initCandidate`, as long as the symbol resolves to a
routine symbol.
* Overload resolution now checks the generic params for constraints and
correct parameter count (ignoring implicit params). If these don't
match, the entire overload is considered as not matching and not
instantiated.
* Special error messages are added for mismatching/missing/extra generic
params. This is almost all of the diff in `semcall`.
* Procs with matching generic parameters now instantiate only the type
of the signature in overload resolution, not the proc itself, which also
works for templates and macros.
Unfortunately we can't entirely remove instantiations because overload
resolution can't handle some cases with uninstantiated types even though
it's resolved in the binding (see the last 2 blocks in
`texplicitgenerics`). There are also some instantiation issues with
default params that #24005 didn't fix but I didn't want this to become
the 3rd huge generics PR in a row so I didn't dive too deep into trying
to fix them. There is still a minor instantiation fix in `semtypinst`
though for subscripts in calls.
Additional changes:
* Overloading of `[]` wasn't documented properly, it somewhat is now
because we need to mention the limitation that it can't be done for
generic procs/types.
* Tests can now enable the new type mismatch errors with just
`-d:testsConciseTypeMismatch` in the command.
Package PRs:
- using fork for now:
[combparser](https://github.com/PMunch/combparser/pull/7) (partial
generic instantiation)
- merged: [cligen](https://github.com/c-blake/cligen/pull/233) (partial
generic instantiation but non-overloaded + template)
- merged: [neo](https://github.com/andreaferretti/neo/pull/56) (trying
to instantiate template with no generic param)
fixes#23998
In `fitNode` the first symbol of a symchoice that expects an enum type
with the same enum type is given as the result of the `fitNode`. But
`getConstExpr` is also called on it, which will return a `nil` node for
nodes that aren't constant but have the enum type, like variables or
proc parameters. Instead we just return the node directly since it's
already typed.
Normally, this `if` branch in `fitNode` shouldn't exist since
`paramTypesMatch` handles it, but the way pure enum symbols work makes
it really impractical to check their ambiguity, which `paramTypesMatch`
won't like. If it causes problems for regular enums we can restrict this
branch to just pure enums until they are hopefully eventually removed.
fixes#10440, fixes#13871, fixes#14665, fixes#19672, fixes#23677
The false positive in #23677 was caused by behavior in
`implicitlyDiscardable` where only the last node of `if`/`case`/`try`
etc expressions were considered, as in the final node of the final
branch (in this case `else`). To fix this we use the same iteration in
`implicitlyDiscardable` that we use in `endsInNoReturn`, with the
difference that for an `if`/`case`/`try` statement to be implicitly
discardable, all of its branches must be implicitly discardable.
`noreturn` calls are also considered implicitly discardable for this
reason, otherwise stuff like `if true: discardableCall() else: error()`
doesn't compile.
However `endsInNoReturn` also had bugs, one where `finally` was
considered in noreturn checking when it shouldn't, another where only
`nkIfStmt` was checked and not `nkIfExpr`, and the node given for the
error message was bad. So `endsInNoReturn` now skips over
`skipForDiscardable` which no longer contains
`nkIfStmt`/`nkCaseStmt`/`nkTryStmt`, stores the first encountered
returning node in a var parameter for the error message, and handles
`finally` and `nkIfExpr`.
Fixing #23677 already broke a line in `syncio` so some package code
might be affected.
While looking at the CI I noticed that there's a couple false positives
for `case` statements that cannot be checked for exhaustiveness since my
changes, this should resolve them.
---------
Co-authored-by: SirOlaf <>
**TODO**
- [x] fixes changelog
With the new option `nimPreviewVtables`, `methods` are confined in the
same module where the type of the first parameter is defined
- [x] make it opt in after CI checks its feasibility
## In the following-up PRs
- [ ] in the following PRs, refactor code into a more efficient one
- [ ] cpp needs special treatments since it cannot embed array in light
of the preceding limits: ref
https://github.com/nim-lang/Nim/pull/20977#discussion_r1035528927; we
can support cpp backends with vtable implementations later on the
comprise that uses indirect vtable access
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
Attempts to move the generic instantiation to the module that uses it.
This should decrease re-compilation times as the source module where the
generic lives doesnt need to be recompiled
---------
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
Move `symFromType` and `symNodeFromType` from `sem`, and `isSelf` and
`makeTypeDesc` from `concepts` into `semdata`.
`makeTypeDesc` was moved out from semdata [when the `concepts` module
was
added](6278b5d89a),
so its old position might have been intended. If not, `isSelf` can also
go in `ast`.
* fix generic param substitution in templates
fixes#13527, fixes#17240, fixes#6340, fixes#20033, fixes#19576, fixes#19076
* fix bare except in test, test updated packages in CI
* fixes#22301; rejects branch initialization with a runtime discriminator with defaults
* undefault nimPreviewRangeDefault
* fixes tests
* use oldCheckDefault
* refactoring in preparation for better, simpler name mangling that works with IC flawlessly
* use new disamb field
* see if this makes tests green
* make tests green again
* fixes#19795; remove parse pipeline
* isScript
* fixes nimscriptapi
* don't touch reorder
* check script
* fixes tests
* it seems implicit imports of system cause troubles
* access the first child of `nkStmtList`
* ignore comments
* minor messages
* perhaps increases hloLoopDetector
* the module is a stmtList, which changes the errors
* fixes nimdoc
* fixes tlinter
* fixes nim secret tests
* fixes arc_misc
* fixes nim secret tests again
* safe; fixes one more test
* GlobalError is the root cause too
* fixes parsing errors
* put emit types to the cfsForwardTypes section
* fixes#11852; `{.push checks:off}` now works in procs
* disable navigator
* fixes nimdoc
* add tests for JS
* fixes nimsuggest
* micro implementation of rfc 149
refs https://github.com/nim-lang/RFCs/issues/149
* number/array/seq literals, more statements
* try fix number literal alias issue
* renew expectedType with if/case/try branch types
* fix (nerf) index type handling and float typed int
* use typeAllowed
* tweaks + const test (tested locally) [skip ci]
* fill out more of the checklist
* more literals, change @ order, type conversions
Not copying the full call tree before the typedesc call check
in `semIndirectOp` is also a small performance improvement.
* disable self-conversion warning
* revert type conversions (maybe separate op later)
* deal with CI for now (seems unrelated), try enums
* workaround CI different way
* proper fix
* again
* see sizes
* lol
* overload selection, simplify int literal -> float
* range, new @ solution, try use fitNode for nil
* use new magic
* try fix ranges, new magic, deal with #20193
* add documentation, support templates
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
