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| author | Rob Findley <rfindley@google.com> | 2021-08-10 14:00:56 -0400 |
|---|---|---|
| committer | Robert Findley <rfindley@google.com> | 2021-08-14 15:14:35 +0000 |
| commit | fc27eb50ffcada3d4f5e7e00a5c120f474cc0da4 (patch) | |
| tree | 5e83de648776a3b1b1654774814b723d8e662d0b /src/cmd/compile/internal/types2/typexpr.go | |
| parent | 7eaabae84d8b69216356b84ebc7c86917100f99a (diff) | |
| download | go-fc27eb50ffcada3d4f5e7e00a5c120f474cc0da4.tar.gz go-fc27eb50ffcada3d4f5e7e00a5c120f474cc0da4.zip | |
cmd/compile/internal/types2: merge Instantiate and InstantiateLazy
Instantiate and InstantiateLazy have the same signature; on first
principles, if Instantiate should work for importers it should be
possible to consolidate these APIs.
This CL does this. In order to make it work, a typMap needs to be
threaded through type expansion to prevent infinite recursion in the
case that the Checker is nil.
Notably, Named types now must be expanded before returning from
Underlying(). This makes Underlying generally unsafe to call while type
checking a package, so a helper function safeUnderlying is added to
provide the previous behavior. This is probably overly conservative at
most call sites, but cleanup is deferred to a later CL.
Change-Id: I03cfb75bea0750862cd6eea4e3cdc875a7daa989
Reviewed-on: https://go-review.googlesource.com/c/go/+/341855
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Diffstat (limited to 'src/cmd/compile/internal/types2/typexpr.go')
| -rw-r--r-- | src/cmd/compile/internal/types2/typexpr.go | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go index 6a9eacd31d..a53319c153 100644 --- a/src/cmd/compile/internal/types2/typexpr.go +++ b/src/cmd/compile/internal/types2/typexpr.go @@ -225,7 +225,7 @@ func (check *Checker) typInternal(e0 syntax.Expr, def *Named) (T Type) { // Test case: type T[P any] *T[P] // TODO(gri) investigate if that's a bug or to be expected // (see also analogous comment in Checker.instantiate). - under = T.Underlying() + under = safeUnderlying(T) } if T == under { check.trace(e0.Pos(), "=> %s // %s", T, goTypeName(T)) @@ -422,9 +422,13 @@ func (check *Checker) typOrNil(e syntax.Expr) Type { } func (check *Checker) instantiatedType(x syntax.Expr, targsx []syntax.Expr, def *Named) Type { - base := check.genericType(x, true) - if base == Typ[Invalid] { - return base // error already reported + gtyp := check.genericType(x, true) + if gtyp == Typ[Invalid] { + return gtyp // error already reported + } + base, _ := gtyp.(*Named) + if base == nil { + panic(fmt.Sprintf("%v: cannot instantiate %v", x.Pos(), gtyp)) } // evaluate arguments @@ -440,7 +444,7 @@ func (check *Checker) instantiatedType(x syntax.Expr, targsx []syntax.Expr, def posList[i] = syntax.StartPos(arg) } - typ := check.InstantiateLazy(x.Pos(), base, targs, posList, true) + typ := check.instantiateLazy(x.Pos(), base, targs, posList, true) def.setUnderlying(typ) // make sure we check instantiation works at least once |