diff options
author | Dan Scales <danscales@google.com> | 2020-12-01 14:48:03 -0800 |
---|---|---|
committer | Dan Scales <danscales@google.com> | 2021-01-20 22:53:32 +0000 |
commit | 1760d736f61265b3c78a6a48f2e1904341806643 (patch) | |
tree | fbf7575c435f30ae41e97589adeca569cbe0225e /src/cmd/compile/internal/inline | |
parent | 92cb157cf3aa51d28e441dbb2b671795f22140f8 (diff) | |
download | go-1760d736f61265b3c78a6a48f2e1904341806643.tar.gz go-1760d736f61265b3c78a6a48f2e1904341806643.zip |
[dev.regabi] cmd/compile: exporting, importing, and inlining functions with OCLOSURE
I have exporting, importing, and inlining of functions with closures
working in all cases (issue #28727). all.bash runs successfully without
errors.
Approach:
- Write out the Func type, Dcls, ClosureVars, and Body when exporting
an OCLOSURE.
- When importing an OCLOSURE, read in the type, dcls, closure vars,
and body, and then do roughly equivalent code to (*noder).funcLit
- During inlining of a closure within inlined function, create new
nodes for all params and local variables (including closure
variables), so they can have a new Curfn and some other field
values. Must substitute not only on the Nbody of the closure, but
also the Type, Cvars, and Dcl fields.
Fixes #28727
Change-Id: I4da1e2567c3fa31a5121afbe82dc4e5ee32b3170
Reviewed-on: https://go-review.googlesource.com/c/go/+/283112
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
Diffstat (limited to 'src/cmd/compile/internal/inline')
-rw-r--r-- | src/cmd/compile/internal/inline/inl.go | 264 |
1 files changed, 242 insertions, 22 deletions
diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go index aa194ebab2..7778bc56c4 100644 --- a/src/cmd/compile/internal/inline/inl.go +++ b/src/cmd/compile/internal/inline/inl.go @@ -180,7 +180,7 @@ func CanInline(fn *ir.Func) { n.Func.Inl = &ir.Inline{ Cost: inlineMaxBudget - visitor.budget, Dcl: pruneUnusedAutos(n.Defn.(*ir.Func).Dcl, &visitor), - Body: ir.DeepCopyList(src.NoXPos, fn.Body), + Body: inlcopylist(fn.Body), } if base.Flag.LowerM > 1 { @@ -217,10 +217,8 @@ func Inline_Flood(n *ir.Name, exportsym func(*ir.Name)) { typecheck.ImportedBody(fn) - // Recursively identify all referenced functions for - // reexport. We want to include even non-called functions, - // because after inlining they might be callable. - ir.VisitList(ir.Nodes(fn.Inl.Body), func(n ir.Node) { + var doFlood func(n ir.Node) + doFlood = func(n ir.Node) { switch n.Op() { case ir.OMETHEXPR, ir.ODOTMETH: Inline_Flood(ir.MethodExprName(n), exportsym) @@ -239,15 +237,16 @@ func Inline_Flood(n *ir.Name, exportsym func(*ir.Name)) { // Okay, because we don't yet inline indirect // calls to method values. case ir.OCLOSURE: - // If the closure is inlinable, we'll need to - // flood it too. But today we don't support - // inlining functions that contain closures. - // - // When we do, we'll probably want: - // inlFlood(n.Func.Closure.Func.Nname) - base.Fatalf("unexpected closure in inlinable function") + // VisitList doesn't visit closure bodies, so force a + // recursive call to VisitList on the body of the closure. + ir.VisitList(n.(*ir.ClosureExpr).Func.Body, doFlood) } - }) + } + + // Recursively identify all referenced functions for + // reexport. We want to include even non-called functions, + // because after inlining they might be callable. + ir.VisitList(ir.Nodes(fn.Inl.Body), doFlood) } // hairyVisitor visits a function body to determine its inlining @@ -360,8 +359,13 @@ func (v *hairyVisitor) doNode(n ir.Node) error { // the right panic value, so it needs an argument frame. return errors.New("call to recover") - case ir.OCLOSURE, - ir.ORANGE, + case ir.OCLOSURE: + // TODO(danscales) - fix some bugs when budget is lowered below 30 + // Maybe make budget proportional to number of closure variables, e.g.: + //v.budget -= int32(len(n.(*ir.ClosureExpr).Func.ClosureVars) * 3) + v.budget -= 30 + + case ir.ORANGE, ir.OSELECT, ir.OGO, ir.ODEFER, @@ -449,6 +453,52 @@ func isBigFunc(fn *ir.Func) bool { }) } +// inlcopylist (together with inlcopy) recursively copies a list of nodes, except +// that it keeps the same ONAME, OTYPE, and OLITERAL nodes. It is used for copying +// the body and dcls of an inlineable function. +func inlcopylist(ll []ir.Node) []ir.Node { + s := make([]ir.Node, len(ll)) + for i, n := range ll { + s[i] = inlcopy(n) + } + return s +} + +// inlcopy is like DeepCopy(), but does extra work to copy closures. +func inlcopy(n ir.Node) ir.Node { + var edit func(ir.Node) ir.Node + edit = func(x ir.Node) ir.Node { + switch x.Op() { + case ir.ONAME, ir.OTYPE, ir.OLITERAL, ir.ONIL: + return x + } + m := ir.Copy(x) + ir.EditChildren(m, edit) + if x.Op() == ir.OCLOSURE { + x := x.(*ir.ClosureExpr) + // Need to save/duplicate x.Func.Nname, + // x.Func.Nname.Ntype, x.Func.Dcl, x.Func.ClosureVars, and + // x.Func.Body for iexport and local inlining. + oldfn := x.Func + newfn := ir.NewFunc(oldfn.Pos()) + if oldfn.ClosureCalled() { + newfn.SetClosureCalled(true) + } + m.(*ir.ClosureExpr).Func = newfn + newfn.Nname = ir.NewNameAt(oldfn.Nname.Pos(), oldfn.Nname.Sym()) + // XXX OK to share fn.Type() ?? + newfn.Nname.SetType(oldfn.Nname.Type()) + newfn.Nname.Ntype = inlcopy(oldfn.Nname.Ntype).(ir.Ntype) + newfn.Body = inlcopylist(oldfn.Body) + // Make shallow copy of the Dcl and ClosureVar slices + newfn.Dcl = append([]*ir.Name(nil), oldfn.Dcl...) + newfn.ClosureVars = append([]*ir.Name(nil), oldfn.ClosureVars...) + } + return m + } + return edit(n) +} + // Inlcalls/nodelist/node walks fn's statements and expressions and substitutes any // calls made to inlineable functions. This is the external entry point. func InlineCalls(fn *ir.Func) { @@ -925,6 +975,7 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b inlvars: inlvars, bases: make(map[*src.PosBase]*src.PosBase), newInlIndex: newIndex, + fn: fn, } subst.edit = subst.node @@ -1031,6 +1082,12 @@ type inlsubst struct { newInlIndex int edit func(ir.Node) ir.Node // cached copy of subst.node method value closure + + // If non-nil, we are inside a closure inside the inlined function, and + // newclofn is the Func of the new inlined closure. + newclofn *ir.Func + + fn *ir.Func // For debug -- the func that is being inlined } // list inlines a list of nodes. @@ -1042,6 +1099,157 @@ func (subst *inlsubst) list(ll ir.Nodes) []ir.Node { return s } +// fields returns a list of the fields of a struct type representing receiver, +// params, or results, after duplicating the field nodes and substituting the +// Nname nodes inside the field nodes. +func (subst *inlsubst) fields(oldt *types.Type) []*types.Field { + oldfields := oldt.FieldSlice() + newfields := make([]*types.Field, len(oldfields)) + for i := range oldfields { + newfields[i] = oldfields[i].Copy() + if oldfields[i].Nname != nil { + newfields[i].Nname = subst.node(oldfields[i].Nname.(*ir.Name)) + } + } + return newfields +} + +// clovar creates a new ONAME node for a local variable or param of a closure +// inside a function being inlined. +func (subst *inlsubst) clovar(n *ir.Name) *ir.Name { + // TODO(danscales): want to get rid of this shallow copy, with code like the + // following, but it is hard to copy all the necessary flags in a maintainable way. + // m := ir.NewNameAt(n.Pos(), n.Sym()) + // m.Class = n.Class + // m.SetType(n.Type()) + // m.SetTypecheck(1) + //if n.IsClosureVar() { + // m.SetIsClosureVar(true) + //} + m := &ir.Name{} + *m = *n + m.Curfn = subst.newclofn + if n.Defn != nil && n.Defn.Op() == ir.ONAME { + if !n.IsClosureVar() { + base.FatalfAt(n.Pos(), "want closure variable, got: %+v", n) + } + if n.Sym().Pkg != types.LocalPkg { + // If the closure came from inlining a function from + // another package, must change package of captured + // variable to localpkg, so that the fields of the closure + // struct are local package and can be accessed even if + // name is not exported. If you disable this code, you can + // reproduce the problem by running 'go test + // go/internal/srcimporter'. TODO(mdempsky) - maybe change + // how we create closure structs? + m.SetSym(types.LocalPkg.Lookup(n.Sym().Name)) + } + // Make sure any inlvar which is the Defn + // of an ONAME closure var is rewritten + // during inlining. Don't substitute + // if Defn node is outside inlined function. + if subst.inlvars[n.Defn.(*ir.Name)] != nil { + m.Defn = subst.node(n.Defn) + } + } + if n.Outer != nil { + // Either the outer variable is defined in function being inlined, + // and we will replace it with the substituted variable, or it is + // defined outside the function being inlined, and we should just + // skip the outer variable (the closure variable of the function + // being inlined). + s := subst.node(n.Outer).(*ir.Name) + if s == n.Outer { + s = n.Outer.Outer + } + m.Outer = s + } + return m +} + +// closure does the necessary substitions for a ClosureExpr n and returns the new +// closure node. +func (subst *inlsubst) closure(n *ir.ClosureExpr) ir.Node { + m := ir.Copy(n) + m.SetPos(subst.updatedPos(m.Pos())) + ir.EditChildren(m, subst.edit) + + //fmt.Printf("Inlining func %v with closure into %v\n", subst.fn, ir.FuncName(ir.CurFunc)) + + // The following is similar to funcLit + oldfn := n.Func + newfn := ir.NewFunc(oldfn.Pos()) + // These three lines are not strictly necessary, but just to be clear + // that new function needs to redo typechecking and inlinability. + newfn.SetTypecheck(0) + newfn.SetInlinabilityChecked(false) + newfn.Inl = nil + newfn.SetIsHiddenClosure(true) + newfn.Nname = ir.NewNameAt(n.Pos(), ir.BlankNode.Sym()) + newfn.Nname.Func = newfn + newfn.Nname.Ntype = subst.node(oldfn.Nname.Ntype).(ir.Ntype) + newfn.Nname.Defn = newfn + + m.(*ir.ClosureExpr).Func = newfn + newfn.OClosure = m.(*ir.ClosureExpr) + + if subst.newclofn != nil { + //fmt.Printf("Inlining a closure with a nested closure\n") + } + prevxfunc := subst.newclofn + + // Mark that we are now substituting within a closure (within the + // inlined function), and create new nodes for all the local + // vars/params inside this closure. + subst.newclofn = newfn + newfn.Dcl = nil + newfn.ClosureVars = nil + for _, oldv := range oldfn.Dcl { + newv := subst.clovar(oldv) + subst.inlvars[oldv] = newv + newfn.Dcl = append(newfn.Dcl, newv) + } + for _, oldv := range oldfn.ClosureVars { + newv := subst.clovar(oldv) + subst.inlvars[oldv] = newv + newfn.ClosureVars = append(newfn.ClosureVars, newv) + } + + // Need to replace ONAME nodes in + // newfn.Type().FuncType().Receiver/Params/Results.FieldSlice().Nname + oldt := oldfn.Type() + newrecvs := subst.fields(oldt.Recvs()) + var newrecv *types.Field + if len(newrecvs) > 0 { + newrecv = newrecvs[0] + } + newt := types.NewSignature(oldt.Pkg(), newrecv, + subst.fields(oldt.Params()), subst.fields(oldt.Results())) + + newfn.Nname.SetType(newt) + newfn.Body = subst.list(oldfn.Body) + + // Remove the nodes for the current closure from subst.inlvars + for _, oldv := range oldfn.Dcl { + delete(subst.inlvars, oldv) + } + for _, oldv := range oldfn.ClosureVars { + delete(subst.inlvars, oldv) + } + // Go back to previous closure func + subst.newclofn = prevxfunc + + // Actually create the named function for the closure, now that + // the closure is inlined in a specific function. + m.SetTypecheck(0) + if oldfn.ClosureCalled() { + typecheck.Callee(m) + } else { + typecheck.Expr(m) + } + return m +} + // node recursively copies a node from the saved pristine body of the // inlined function, substituting references to input/output // parameters with ones to the tmpnames, and substituting returns with @@ -1056,13 +1264,17 @@ func (subst *inlsubst) node(n ir.Node) ir.Node { n := n.(*ir.Name) // Handle captured variables when inlining closures. - if n.IsClosureVar() { + if n.IsClosureVar() && subst.newclofn == nil { o := n.Outer + // Deal with case where sequence of closures are inlined. + // TODO(danscales) - write test case to see if we need to + // go up multiple levels. + if o.Curfn != ir.CurFunc { + o = o.Outer + } + // make sure the outer param matches the inlining location - // NB: if we enabled inlining of functions containing OCLOSURE or refined - // the reassigned check via some sort of copy propagation this would most - // likely need to be changed to a loop to walk up to the correct Param if o == nil || o.Curfn != ir.CurFunc { base.Fatalf("%v: unresolvable capture %v\n", ir.Line(n), n) } @@ -1098,6 +1310,10 @@ func (subst *inlsubst) node(n ir.Node) ir.Node { } case ir.ORETURN: + if subst.newclofn != nil { + // Don't do special substitutions if inside a closure + break + } // Since we don't handle bodies with closures, // this return is guaranteed to belong to the current inlined function. n := n.(*ir.ReturnStmt) @@ -1136,6 +1352,10 @@ func (subst *inlsubst) node(n ir.Node) ir.Node { return m case ir.OLABEL: + if subst.newclofn != nil { + // Don't do special substitutions if inside a closure + break + } n := n.(*ir.LabelStmt) m := ir.Copy(n).(*ir.LabelStmt) m.SetPos(subst.updatedPos(m.Pos())) @@ -1143,10 +1363,10 @@ func (subst *inlsubst) node(n ir.Node) ir.Node { p := fmt.Sprintf("%s·%d", n.Label.Name, inlgen) m.Label = typecheck.Lookup(p) return m - } - if n.Op() == ir.OCLOSURE { - base.Fatalf("cannot inline function containing closure: %+v", n) + case ir.OCLOSURE: + return subst.closure(n.(*ir.ClosureExpr)) + } m := ir.Copy(n) |