From 2493c727425547db935a1c6e519bc19d01476380 Mon Sep 17 00:00:00 2001 From: Cuong Manh Le Date: Thu, 24 Jun 2021 23:05:09 +0700 Subject: [PATCH] [dev.typeparams] cmd/compile: rewrite method call into method expression during escape analysis CL 330331 extended escape analysis to analyze method expression calls the same as normal method calls. We can now simply desugar method calls into function calls in escape analysis. To do this, two things must be changed: - Folding the rewrite method call to method expression call into an export function in typecheck package, so others can re-use it. - walkCall now have to call usemethod for method expression calls. (It seems to me this is a bug in current tip, because if one write (*rtype).Method(typ, i) in package "reflect", then the function won't be marked with AttrReflectMethod) Passes toolstash -cmp. Change-Id: I4745ab6110b417c7fd32949cc799811a882cd2ec Reviewed-on: https://go-review.googlesource.com/c/go/+/330671 Trust: Cuong Manh Le Run-TryBot: Cuong Manh Le TryBot-Result: Go Bot Reviewed-by: Matthew Dempsky --- .../internal/devirtualize/devirtualize.go | 1 - src/cmd/compile/internal/escape/call.go | 1 + src/cmd/compile/internal/typecheck/func.go | 21 ++++++++++++++++++- src/cmd/compile/internal/walk/expr.go | 16 ++------------ 4 files changed, 23 insertions(+), 16 deletions(-) diff --git a/src/cmd/compile/internal/devirtualize/devirtualize.go b/src/cmd/compile/internal/devirtualize/devirtualize.go index 60ba208d08..f52499e07f 100644 --- a/src/cmd/compile/internal/devirtualize/devirtualize.go +++ b/src/cmd/compile/internal/devirtualize/devirtualize.go @@ -50,7 +50,6 @@ func Call(call *ir.CallExpr) { if base.Flag.LowerM != 0 { base.WarnfAt(call.Pos(), "devirtualizing %v to %v", sel, typ) } - call.SetOp(ir.OCALLMETH) call.X = x case ir.ODOTINTER: // Promoted method from embedded interface-typed field (#42279). diff --git a/src/cmd/compile/internal/escape/call.go b/src/cmd/compile/internal/escape/call.go index b8e28cd46a..62727a8ef8 100644 --- a/src/cmd/compile/internal/escape/call.go +++ b/src/cmd/compile/internal/escape/call.go @@ -46,6 +46,7 @@ func (e *escape) callCommon(ks []hole, call ir.Node, init *ir.Nodes, wrapper *ir case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER: call := call.(*ir.CallExpr) typecheck.FixVariadicCall(call) + typecheck.FixMethodCall(call) // Pick out the function callee, if statically known. // diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go index 031279f42c..00770c87cf 100644 --- a/src/cmd/compile/internal/typecheck/func.go +++ b/src/cmd/compile/internal/typecheck/func.go @@ -15,7 +15,7 @@ import ( "go/token" ) -// package all the arguments that match a ... T parameter into a []T. +// MakeDotArgs package all the arguments that match a ... T parameter into a []T. func MakeDotArgs(pos src.XPos, typ *types.Type, args []ir.Node) ir.Node { var n ir.Node if len(args) == 0 { @@ -57,6 +57,25 @@ func FixVariadicCall(call *ir.CallExpr) { call.IsDDD = true } +// FixMethodCall rewrites a method call t.M(...) into a function call T.M(t, ...). +func FixMethodCall(call *ir.CallExpr) { + if call.X.Op() != ir.ODOTMETH { + return + } + + dot := call.X.(*ir.SelectorExpr) + + fn := Expr(ir.NewSelectorExpr(dot.Pos(), ir.OXDOT, ir.TypeNode(dot.X.Type()), dot.Selection.Sym)) + + args := make([]ir.Node, 1+len(call.Args)) + args[0] = dot.X + copy(args[1:], call.Args) + + call.SetOp(ir.OCALLFUNC) + call.X = fn + call.Args = args +} + // ClosureType returns the struct type used to hold all the information // needed in the closure for clo (clo must be a OCLOSURE node). // The address of a variable of the returned type can be cast to a func. diff --git a/src/cmd/compile/internal/walk/expr.go b/src/cmd/compile/internal/walk/expr.go index bbf289d90e..d8bded8075 100644 --- a/src/cmd/compile/internal/walk/expr.go +++ b/src/cmd/compile/internal/walk/expr.go @@ -489,7 +489,7 @@ func walkAddString(n *ir.AddStringExpr, init *ir.Nodes) ir.Node { // walkCall walks an OCALLFUNC, OCALLINTER, or OCALLMETH node. func walkCall(n *ir.CallExpr, init *ir.Nodes) ir.Node { - if n.Op() == ir.OCALLINTER || n.Op() == ir.OCALLMETH { + if n.Op() == ir.OCALLINTER || n.X.Op() == ir.OMETHEXPR { // We expect both interface call reflect.Type.Method and concrete // call reflect.(*rtype).Method. usemethod(n) @@ -549,20 +549,8 @@ func walkCall1(n *ir.CallExpr, init *ir.Nodes) { } n.SetWalked(true) - // If this is a method call t.M(...), - // rewrite into a function call T.M(t, ...). - // TODO(mdempsky): Do this right after type checking. if n.Op() == ir.OCALLMETH { - withRecv := make([]ir.Node, len(n.Args)+1) - dot := n.X.(*ir.SelectorExpr) - withRecv[0] = dot.X - copy(withRecv[1:], n.Args) - n.Args = withRecv - - dot = ir.NewSelectorExpr(dot.Pos(), ir.OXDOT, ir.TypeNode(dot.X.Type()), dot.Selection.Sym) - - n.SetOp(ir.OCALLFUNC) - n.X = typecheck.Expr(dot) + typecheck.FixMethodCall(n) } args := n.Args