From 767fbe01aeb32d8fe72bb40fa0cc144a7263045b Mon Sep 17 00:00:00 2001 From: Matthew Dempsky Date: Wed, 3 May 2023 14:53:03 -0700 Subject: [PATCH] cmd/compile: fix compilation of inferred type arguments Previously, type arguments could only be inferred for generic functions in call expressions, whereas with the reverse type inference proposal they can now be inferred in assignment contexts too. As a consequence, we now need to check Info.Instances to find the inferred type for more cases now. Updates #59338. Fixes #59955. Change-Id: I9b6465395869459c2387d0424febe7337b28b90e Reviewed-on: https://go-review.googlesource.com/c/go/+/492455 Auto-Submit: Matthew Dempsky TryBot-Result: Gopher Robot Reviewed-by: Robert Griesemer Run-TryBot: Matthew Dempsky --- src/cmd/compile/internal/noder/writer.go | 15 +++++++++++++-- test/fixedbugs/issue59338.go | 16 +++++++--------- 2 files changed, 20 insertions(+), 11 deletions(-) diff --git a/src/cmd/compile/internal/noder/writer.go b/src/cmd/compile/internal/noder/writer.go index 72c7a1fc86..178c3eb1a9 100644 --- a/src/cmd/compile/internal/noder/writer.go +++ b/src/cmd/compile/internal/noder/writer.go @@ -123,14 +123,25 @@ func (pw *pkgWriter) unexpected(what string, p poser) { } func (pw *pkgWriter) typeAndValue(x syntax.Expr) syntax.TypeAndValue { - tv := x.GetTypeInfo() - if tv.Type == nil { + tv, ok := pw.maybeTypeAndValue(x) + if !ok { pw.fatalf(x, "missing Types entry: %v", syntax.String(x)) } return tv } + func (pw *pkgWriter) maybeTypeAndValue(x syntax.Expr) (syntax.TypeAndValue, bool) { tv := x.GetTypeInfo() + + // If x is a generic function whose type arguments are inferred + // from assignment context, then we need to find its inferred type + // in Info.Instances instead. + if name, ok := x.(*syntax.Name); ok { + if inst, ok := pw.info.Instances[name]; ok { + tv.Type = inst.Type + } + } + return tv, tv.Type != nil } diff --git a/test/fixedbugs/issue59338.go b/test/fixedbugs/issue59338.go index dc8604f319..8ba3fd2b3b 100644 --- a/test/fixedbugs/issue59338.go +++ b/test/fixedbugs/issue59338.go @@ -21,15 +21,13 @@ func main() { panic(2) } - // Disabled for now - requires some noder work - // TODO fix this - // if g3(g1, 3) != g1(3) { - // panic(3) - // } - - // if g4(g2, 4) != "" { - // panic(4) - // } + if g3(g1, 3) != g1(3) { + panic(3) + } + + if g4(g2, 4) != "" { + panic(4) + } } func g1[P any](x P) P { return x } -- 2.50.0