From c3fa51c9a2288ae6441f54e3a59d82015f0b7728 Mon Sep 17 00:00:00 2001 From: Dan Scales Date: Thu, 6 May 2021 14:21:47 -0700 Subject: [PATCH] cmd/compile: changed representation of typeparam bound in types1 Especially with typesets, we should be able to fully represent a typeparam bound as just another type (actually an interface type). Change the representation of a typeparam in types1 to include a bound, which is just a type. Changed the signature for NewTypeParam() to take a sym, and not a package, since we always set the sym (name) of the typeparam when creating it. No need for an extra pkg field in Typeparam. Also added index field in the types1 representation of typeparam. This is especially needed to correctly export the typeparam, and re-import it as a types2 type (which requires the index to be set correctly). Change-Id: I50200e2489a97898c37d292b2bd025df790b0277 Reviewed-on: https://go-review.googlesource.com/c/go/+/319929 Reviewed-by: Robert Griesemer Trust: Robert Griesemer Trust: Dan Scales Run-TryBot: Dan Scales TryBot-Result: Go Bot --- src/cmd/compile/internal/noder/types.go | 7 ++--- src/cmd/compile/internal/types/type.go | 38 +++++++++++++++++++++---- src/cmd/compile/internal/types2/type.go | 5 ++++ 3 files changed, 40 insertions(+), 10 deletions(-) diff --git a/src/cmd/compile/internal/noder/types.go b/src/cmd/compile/internal/noder/types.go index 8680559a412..8a2c023a1a3 100644 --- a/src/cmd/compile/internal/noder/types.go +++ b/src/cmd/compile/internal/noder/types.go @@ -204,18 +204,15 @@ func (g *irgen) typ0(typ types2.Type) *types.Type { return types.NewInterface(g.tpkg(typ), append(embeddeds, methods...)) case *types2.TypeParam: - tp := types.NewTypeParam(g.tpkg(typ)) // Save the name of the type parameter in the sym of the type. // Include the types2 subscript in the sym name sym := g.pkg(typ.Obj().Pkg()).Lookup(types2.TypeString(typ, func(*types2.Package) string { return "" })) - tp.SetSym(sym) + tp := types.NewTypeParam(sym, typ.Index()) // Set g.typs[typ] in case the bound methods reference typ. g.typs[typ] = tp - // TODO(danscales): we don't currently need to use the bounds - // anywhere, so eventually we can probably remove. bound := g.typ1(typ.Bound()) - *tp.Methods() = *bound.Methods() + tp.SetBound(bound) return tp case *types2.Tuple: diff --git a/src/cmd/compile/internal/types/type.go b/src/cmd/compile/internal/types/type.go index 1a9aa6916a2..d3c02fc56d3 100644 --- a/src/cmd/compile/internal/types/type.go +++ b/src/cmd/compile/internal/types/type.go @@ -151,7 +151,7 @@ type Type struct { // TARRAY: *Array // TSLICE: Slice // TSSA: string - // TTYPEPARAM: *Interface (though we may not need to store/use the Interface info) + // TTYPEPARAM: *Typeparam Extra interface{} // Width is the width of this Type in bytes. @@ -377,6 +377,12 @@ type Interface struct { pkg *Pkg } +// Typeparam contains Type fields specific to typeparam types. +type Typeparam struct { + index int // type parameter index in source order, starting at 0 + bound *Type +} + // Ptr contains Type fields specific to pointer types. type Ptr struct { Elem *Type // element type @@ -558,7 +564,7 @@ func New(et Kind) *Type { case TRESULTS: t.Extra = new(Results) case TTYPEPARAM: - t.Extra = new(Interface) + t.Extra = new(Typeparam) } return t } @@ -825,6 +831,8 @@ func (t *Type) copy() *Type { case TARRAY: x := *t.Extra.(*Array) nt.Extra = &x + case TTYPEPARAM: + base.Fatalf("typeparam types cannot be copied") case TTUPLE, TSSA, TRESULTS: base.Fatalf("ssa types cannot be copied") } @@ -1766,14 +1774,34 @@ func NewInterface(pkg *Pkg, methods []*Field) *Type { return t } -// NewTypeParam returns a new type param. -func NewTypeParam(pkg *Pkg) *Type { +// NewTypeParam returns a new type param with the specified sym (package and name) +// and specified index within the typeparam list. +func NewTypeParam(sym *Sym, index int) *Type { t := New(TTYPEPARAM) - t.Extra.(*Interface).pkg = pkg + t.sym = sym + t.Extra.(*Typeparam).index = index t.SetHasTParam(true) return t } +// Index returns the index of the type param within its param list. +func (t *Type) Index() int { + t.wantEtype(TTYPEPARAM) + return t.Extra.(*Typeparam).index +} + +// SetBound sets the bound of a typeparam. +func (t *Type) SetBound(bound *Type) { + t.wantEtype(TTYPEPARAM) + t.Extra.(*Typeparam).bound = bound +} + +// Bound returns the bound of a typeparam. +func (t *Type) Bound() *Type { + t.wantEtype(TTYPEPARAM) + return t.Extra.(*Typeparam).bound +} + const BOGUS_FUNARG_OFFSET = -1000000000 func unzeroFieldOffsets(f []*Field) { diff --git a/src/cmd/compile/internal/types2/type.go b/src/cmd/compile/internal/types2/type.go index e6c260ff679..88dedbad452 100644 --- a/src/cmd/compile/internal/types2/type.go +++ b/src/cmd/compile/internal/types2/type.go @@ -760,6 +760,11 @@ func (check *Checker) NewTypeParam(obj *TypeName, index int, bound Type) *TypePa return typ } +// Index returns the index of the type param within its param list. +func (t *TypeParam) Index() int { + return t.index +} + func (t *TypeParam) Bound() *Interface { iface := asInterface(t.bound) // use the type bound position if we have one