From 647bef6c59e201792688d88cdc50ea0c6a68990b Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Tue, 24 Aug 2021 09:28:43 -0700 Subject: go/types: implement NewTypeList and use it instead of composite literals Also, simplify a bit of code in predicates.go. This is a backport of changes in CL 344615 that were made in addition to the changes of the original CL 343933; it brings go/types in sync with types2. Change-Id: I14cd4d4704d29894d0fbb8d129744d65e332ad22 Reviewed-on: https://go-review.googlesource.com/c/go/+/344570 Trust: Robert Griesemer Trust: Dan Scales Run-TryBot: Robert Griesemer TryBot-Result: Go Bot Reviewed-by: Dan Scales --- src/go/types/check.go | 2 +- src/go/types/instantiate.go | 2 +- src/go/types/predicates.go | 8 +++----- src/go/types/subst.go | 2 +- src/go/types/typelists.go | 8 ++++++++ 5 files changed, 14 insertions(+), 8 deletions(-) (limited to 'src') diff --git a/src/go/types/check.go b/src/go/types/check.go index 909bf8d52d..ab3a388e9f 100644 --- a/src/go/types/check.go +++ b/src/go/types/check.go @@ -407,7 +407,7 @@ func (check *Checker) recordInferred(call ast.Expr, targs []Type, sig *Signature assert(call != nil) assert(sig != nil) if m := check.Inferred; m != nil { - m[call] = Inferred{&TypeList{targs}, sig} + m[call] = Inferred{NewTypeList(targs), sig} } } diff --git a/src/go/types/instantiate.go b/src/go/types/instantiate.go index 3ee09b7e84..5f691d5246 100644 --- a/src/go/types/instantiate.go +++ b/src/go/types/instantiate.go @@ -131,7 +131,7 @@ func (check *Checker) instance(pos token.Pos, typ Type, targs []Type) (res Type) tname := NewTypeName(pos, t.obj.pkg, t.obj.name, nil) named := check.newNamed(tname, t, nil, nil, nil) // methods and tparams are set when named is loaded - named.targs = &TypeList{targs} + named.targs = NewTypeList(targs) named.instance = &instance{pos} if check != nil { check.typMap[h] = named diff --git a/src/go/types/predicates.go b/src/go/types/predicates.go index 2f4ef9dace..d4055bb0cc 100644 --- a/src/go/types/predicates.go +++ b/src/go/types/predicates.go @@ -312,16 +312,14 @@ func identical(x, y Type, cmpTags bool, p *ifacePair) bool { return false } - if nargs := len(xargs); nargs > 0 { + if len(xargs) > 0 { // Instances are identical if their original type and type arguments // are identical. if !Identical(x.orig, y.orig) { return false } - for i := 0; i < nargs; i++ { - xa := xargs[i] - ya := yargs[i] - if !Identical(xa, ya) { + for i, xa := range xargs { + if !Identical(xa, yargs[i]) { return false } } diff --git a/src/go/types/subst.go b/src/go/types/subst.go index 8b8d6fb82a..1c53cdaf2c 100644 --- a/src/go/types/subst.go +++ b/src/go/types/subst.go @@ -233,7 +233,7 @@ func (subst *subster) typ(typ Type) Type { // It's ok to provide a nil *Checker because the newly created type // doesn't need to be (lazily) expanded; it's expanded below. named := (*Checker)(nil).newNamed(tname, t.orig, nil, t.tparams, t.methods) // t is loaded, so tparams and methods are available - named.targs = &TypeList{newTArgs} + named.targs = NewTypeList(newTArgs) subst.typMap[h] = named t.expand(subst.typMap) // must happen after typMap update to avoid infinite recursion diff --git a/src/go/types/typelists.go b/src/go/types/typelists.go index a8181404bf..ef8ea1f32b 100644 --- a/src/go/types/typelists.go +++ b/src/go/types/typelists.go @@ -27,6 +27,14 @@ func (l *TParamList) list() []*TypeParam { // TypeList holds a list of types. type TypeList struct{ types []Type } +// NewTypeList returns a new TypeList with the types in list. +func NewTypeList(list []Type) *TypeList { + if len(list) == 0 { + return nil + } + return &TypeList{list} +} + // Len returns the number of types in the list. // It is safe to call on a nil receiver. func (l *TypeList) Len() int { return len(l.list()) } -- cgit v1.2.3-54-g00ecf