[dev.regabi] cmd/compile: call NeedFuncSym in InitLSym

InitLSym is where we're now generating ABI wrappers, so it seems as
good a place as any to make sure we're generating the degenerate
closure wrappers for declared functions and methods.

Change-Id: I097f34bbcee65dee87a97f9ed6f3f38e4cf2e2b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/283312
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/gc/main.go

@@ -20,7 +20,6 @@ import (
 	"cmd/compile/internal/reflectdata"
 	"cmd/compile/internal/ssa"
 	"cmd/compile/internal/ssagen"
-	"cmd/compile/internal/staticdata"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
 	"cmd/compile/internal/walk"
@@ -194,7 +193,6 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 
 	typecheck.Target = new(ir.Package)
 
-	typecheck.NeedFuncSym = staticdata.NeedFuncSym
 	typecheck.NeedITab = func(t, iface *types.Type) { reflectdata.ITabAddr(t, iface) }
 	typecheck.NeedRuntimeType = reflectdata.NeedRuntimeType // TODO(rsc): typenamesym for lock?
 

src/cmd/compile/internal/ssagen/abi.go

@@ -14,6 +14,7 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/escape"
 	"cmd/compile/internal/ir"
+	"cmd/compile/internal/staticdata"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
 	"cmd/internal/obj"
@@ -137,6 +138,8 @@ func ReadSymABIs(file, myimportpath string) {
 // For body-less functions, we only create the LSym; for functions
 // with bodies call a helper to setup up / populate the LSym.
 func InitLSym(f *ir.Func, hasBody bool) {
+	staticdata.NeedFuncSym(f.Sym())
+
 	// FIXME: for new-style ABI wrappers, we set up the lsym at the
 	// point the wrapper is created.
 	if f.LSym != nil && base.Flag.ABIWrap {
@@ -152,7 +155,7 @@ func InitLSym(f *ir.Func, hasBody bool) {
 // makes calls to helpers to create ABI wrappers if needed.
 func selectLSym(f *ir.Func, hasBody bool) {
 	if f.LSym != nil {
-		base.Fatalf("Func.initLSym called twice")
+		base.FatalfAt(f.Pos(), "Func.initLSym called twice on %v", f)
 	}
 
 	if nam := f.Nname; !ir.IsBlank(nam) {

src/cmd/compile/internal/staticdata/data.go

@@ -265,7 +265,7 @@ func FuncLinksym(n *ir.Name) *obj.LSym {
 	return FuncSym(n.Sym()).Linksym()
 }
 
-// NeedFuncSym ensures that s·f is exported.
+// NeedFuncSym ensures that s·f is exported, if needed.
 // It is only used with -dynlink.
 // When not compiling for dynamic linking,
 // the funcsyms are created as needed by
@@ -275,8 +275,13 @@ func FuncLinksym(n *ir.Name) *obj.LSym {
 // So instead, when dynamic linking, we only create
 // the s·f stubs in s's package.
 func NeedFuncSym(s *types.Sym) {
+	if base.Ctxt.InParallel {
+		// The append below probably just needs to lock
+		// funcsymsmu, like in FuncSym.
+		base.Fatalf("NeedFuncSym must be called in serial")
+	}
 	if !base.Ctxt.Flag_dynlink {
-		base.Fatalf("NeedFuncSym: dynlink")
+		return
 	}
 	if s.IsBlank() {
 		return
@@ -287,9 +292,7 @@ func NeedFuncSym(s *types.Sym) {
 		// get funcsyms.
 		return
 	}
-	if _, existed := s.Pkg.LookupOK(ir.FuncSymName(s)); !existed {
-		funcsyms = append(funcsyms, s)
-	}
+	funcsyms = append(funcsyms, s)
 }
 
 func WriteFuncSyms() {

src/cmd/compile/internal/typecheck/func.go

@@ -364,10 +364,6 @@ func tcFunc(n *ir.Func) {
 		n.Nname.SetSym(ir.MethodSym(rcvr.Type, n.Shortname))
 		Declare(n.Nname, ir.PFUNC)
 	}
-
-	if base.Ctxt.Flag_dynlink && !inimport && n.Nname != nil {
-		NeedFuncSym(n.Sym())
-	}
 }
 
 // tcCall typechecks an OCALL node.

src/cmd/compile/internal/typecheck/typecheck.go

@@ -24,7 +24,6 @@ var inimport bool // set during import
 var TypecheckAllowed bool
 
 var (
-	NeedFuncSym     = func(*types.Sym) {}
 	NeedITab        = func(t, itype *types.Type) {}
 	NeedRuntimeType = func(*types.Type) {}
 )
@@ -1140,12 +1139,6 @@ func typecheckMethodExpr(n *ir.SelectorExpr) (res ir.Node) {
 	n.SetOp(ir.OMETHEXPR)
 	n.Selection = m
 	n.SetType(NewMethodType(m.Type, n.X.Type()))
-
-	// Issue 25065. Make sure that we emit the symbol for a local method.
-	if base.Ctxt.Flag_dynlink && !inimport && (t.Sym() == nil || t.Sym().Pkg == types.LocalPkg) {
-		NeedFuncSym(n.FuncName().Sym())
-	}
-
 	return n
 }