case OINDREG:
case ONAME:
case OPARAM:
+ case OCLOSUREVAR:
return 1;
}
return 0;
// Generate an instruction referencing *n
// to force segv on nil pointer dereference.
void
-checkref(Node *n)
+checkref(Node *n, int force)
{
Node m1, m2;
- if(n->type->type->width < unmappedzero)
+ if(!force && isptr[n->type->etype] && n->type->type->width < unmappedzero)
return;
regalloc(&m1, types[TUINTPTR], n);
void
naddr(Node *n, Addr *a, int canemitcode)
{
- Prog *p;
-
a->type = D_NONE;
a->name = D_NONE;
a->reg = NREG;
break;
case OCLOSUREVAR:
- if(!canemitcode)
- fatal("naddr OCLOSUREVAR cannot emit code");
- p = gins(AMOVW, N, N);
- p->from.type = D_OREG;
- p->from.reg = 7;
- p->from.offset = n->xoffset;
- p->to.type = D_REG;
- p->to.reg = 1;
- a->type = D_REG;
- a->reg = 1;
+ a->type = D_OREG;
+ a->reg = 7;
+ a->offset = n->xoffset;
a->sym = S;
break;
case OINDREG:
case ONAME:
case OPARAM:
+ case OCLOSUREVAR:
return 1;
case OADDR:
if(flag_largemodel)
// Generate an instruction referencing *n
// to force segv on nil pointer dereference.
void
-checkref(Node *n)
+checkref(Node *n, int force)
{
Node m;
- if(n->type->type->width < unmappedzero)
+ if(!force && isptr[n->type->etype] && n->type->type->width < unmappedzero)
return;
regalloc(&m, types[TUINTPTR], n);
void
naddr(Node *n, Addr *a, int canemitcode)
{
- Prog *p;
-
a->scale = 0;
a->index = D_NONE;
a->type = D_NONE;
break;
case OCLOSUREVAR:
- if(!canemitcode)
- fatal("naddr OCLOSUREVAR cannot emit code");
- p = gins(AMOVQ, N, N);
- p->from.type = D_DX+D_INDIR;
- p->from.offset = n->xoffset;
- p->to.type = D_BX;
- a->type = D_BX;
+ a->type = D_DX+D_INDIR;
a->sym = S;
+ a->offset = n->xoffset;
break;
case OCFUNC:
case OINDREG:
case ONAME:
case OPARAM:
+ case OCLOSUREVAR:
return 1;
}
return 0;
// Generate an instruction referencing *n
// to force segv on nil pointer dereference.
void
-checkref(Node *n)
+checkref(Node *n, int force)
{
Node m;
- if(n->type->type->width < unmappedzero)
+ if(!force && isptr[n->type->etype] && n->type->type->width < unmappedzero)
return;
regalloc(&m, types[TUINTPTR], n);
void
naddr(Node *n, Addr *a, int canemitcode)
{
- Prog *p;
-
a->scale = 0;
a->index = D_NONE;
a->type = D_NONE;
break;
case OCLOSUREVAR:
- if(!canemitcode)
- fatal("naddr OCLOSUREVAR cannot emit code");
- p = gins(AMOVL, N, N);
- p->from.type = D_DX+D_INDIR;
- p->from.offset = n->xoffset;
- p->to.type = D_BX;
- a->type = D_BX;
+ a->type = D_DX+D_INDIR;
+ a->offset = n->xoffset;
a->sym = S;
break;
return clos;
}
-// Special case for closures that get called in place.
-// Optimize runtime.closure(X, __func__xxxx_, .... ) away
-// to __func__xxxx_(Y ....).
-// On entry, expect n->op == OCALL, n->left->op == OCLOSURE.
+static Node *makepartialcall(Node*, Type*, Node*);
+
void
-walkcallclosure(Node *n, NodeList **init)
+typecheckpartialcall(Node *fn, Node *sym)
+{
+ switch(fn->op) {
+ case ODOTINTER:
+ case ODOTMETH:
+ break;
+ default:
+ fatal("invalid typecheckpartialcall");
+ }
+
+ // Create top-level function.
+ fn->nname = makepartialcall(fn, fn->type, sym);
+ fn->op = OCALLPART;
+ fn->type = fn->right->type;
+}
+
+static Node*
+makepartialcall(Node *fn, Type *t0, Node *meth)
{
- USED(init);
- if (n->op != OCALLFUNC || n->left->op != OCLOSURE) {
- dump("walkcallclosure", n);
- fatal("abuse of walkcallclosure");
+ Node *ptr, *n, *call, *xtype, *xfunc, *cv;
+ Type *rcvrtype, *basetype, *t;
+ NodeList *body, *l, *callargs, *retargs;
+ char *p;
+ Sym *sym;
+ int i;
+
+ // TODO: names are not right
+ rcvrtype = fn->left->type;
+ if(exportname(meth->sym->name))
+ p = smprint("%-hT.%s·fm", rcvrtype, meth->sym->name);
+ else
+ p = smprint("%-hT.(%-S)·fm", rcvrtype, meth->sym);
+ basetype = rcvrtype;
+ if(isptr[rcvrtype->etype])
+ basetype = basetype->type;
+ if(basetype->sym == S)
+ fatal("missing base type for %T", rcvrtype);
+
+ sym = pkglookup(p, basetype->sym->pkg);
+ free(p);
+ if(sym->flags & SymUniq)
+ return sym->def;
+ sym->flags |= SymUniq;
+
+ xtype = nod(OTFUNC, N, N);
+ i = 0;
+ l = nil;
+ callargs = nil;
+ xfunc = nod(ODCLFUNC, N, N);
+ for(t = getinargx(t0)->type; t; t = t->down) {
+ snprint(namebuf, sizeof namebuf, "a%d", i++);
+ n = newname(lookup(namebuf));
+ n->class = PPARAM;
+ xfunc->dcl = list(xfunc->dcl, n);
+ callargs = list(callargs, n);
+ l = list(l, nod(ODCLFIELD, n, typenod(t->type)));
}
+ xtype->list = l;
+ i = 0;
+ l = nil;
+ retargs = nil;
+ for(t = getoutargx(t0)->type; t; t = t->down) {
+ snprint(namebuf, sizeof namebuf, "r%d", i++);
+ n = newname(lookup(namebuf));
+ n->class = PPARAMOUT;
+ xfunc->dcl = list(xfunc->dcl, n);
+ retargs = list(retargs, n);
+ l = list(l, nod(ODCLFIELD, n, typenod(t->type)));
+ }
+ xtype->rlist = l;
- // New arg list for n. First the closure-args
- // and then the original parameter list.
- n->list = concat(n->left->enter, n->list);
- n->left = n->left->closure->nname;
- dowidth(n->left->type);
- n->type = getoutargx(n->left->type);
- // for a single valued function, pull the field type out of the struct
- if (n->type && n->type->type && !n->type->type->down)
- n->type = n->type->type->type;
+ xfunc->dupok = 1;
+ xfunc->nname = newname(sym);
+ xfunc->nname->sym->flags |= SymExported; // disable export
+ xfunc->nname->ntype = xtype;
+ xfunc->nname->defn = xfunc;
+ declare(xfunc->nname, PFUNC);
+
+ // Declare and initialize variable holding receiver.
+ body = nil;
+ cv = nod(OCLOSUREVAR, N, N);
+ cv->xoffset = widthptr;
+ cv->type = rcvrtype;
+ ptr = nod(ONAME, N, N);
+ ptr->sym = lookup("rcvr");
+ ptr->class = PAUTO;
+ ptr->addable = 1;
+ ptr->ullman = 1;
+ ptr->used = 1;
+ ptr->curfn = xfunc;
+ xfunc->dcl = list(xfunc->dcl, ptr);
+ if(isptr[rcvrtype->etype] || isinter(rcvrtype)) {
+ ptr->ntype = typenod(rcvrtype);
+ body = list(body, nod(OAS, ptr, cv));
+ } else {
+ ptr->ntype = typenod(ptrto(rcvrtype));
+ body = list(body, nod(OAS, ptr, nod(OADDR, cv, N)));
+ }
+
+ call = nod(OCALL, nod(OXDOT, ptr, meth), N);
+ call->list = callargs;
+ if(t0->outtuple == 0) {
+ body = list(body, call);
+ } else {
+ n = nod(OAS2, N, N);
+ n->list = retargs;
+ n->rlist = list1(call);
+ body = list(body, n);
+ n = nod(ORETURN, N, N);
+ body = list(body, n);
+ }
+
+ xfunc->nbody = body;
+
+ typecheck(&xfunc, Etop);
+ sym->def = xfunc;
+ xtop = list(xtop, xfunc);
+
+ return xfunc;
+}
+
+Node*
+walkpartialcall(Node *n, NodeList **init)
+{
+ Node *clos, *typ;
+
+ // Create closure in the form of a composite literal.
+ // For x.M with receiver (x) type T, the generated code looks like:
+ //
+ // clos = &struct{F uintptr; R T}{M.T·f, x}
+ //
+ // Like walkclosure above.
+
+ if(isinter(n->left->type)) {
+ n->left = cheapexpr(n->left, init);
+ checknotnil(n->left, init);
+ }
+
+ typ = nod(OTSTRUCT, N, N);
+ typ->list = list1(nod(ODCLFIELD, newname(lookup("F")), typenod(types[TUINTPTR])));
+ typ->list = list(typ->list, nod(ODCLFIELD, newname(lookup("R")), typenod(n->left->type)));
+
+ clos = nod(OCOMPLIT, N, nod(OIND, typ, N));
+ clos->esc = n->esc;
+ clos->right->implicit = 1;
+ clos->list = list1(nod(OCFUNC, n->nname->nname, N));
+ clos->list = list(clos->list, n->left);
+
+ // Force type conversion from *struct to the func type.
+ clos = nod(OCONVNOP, clos, N);
+ clos->type = n->type;
+
+ typecheck(&clos, Erv);
+ // typecheck will insert a PTRLIT node under CONVNOP,
+ // tag it with escape analysis result.
+ clos->left->esc = n->esc;
+ walkexpr(&clos, init);
+
+ return clos;
}
case ORETURN:
cgen_ret(n);
break;
+
+ case OCHECKNOTNIL:
+ checkref(n->left, 1);
}
ret:
if(n->op == OSLICEARR) {
if(!isptr[n->left->type->etype])
fatal("slicearr is supposed to work on pointer: %+N\n", n);
- checkref(n->left);
+ checkref(n->left, 0);
}
if(isnil(n->left)) {
OCALLFUNC, // f()
OCALLMETH, // t.Method()
OCALLINTER, // err.Error()
+ OCALLPART, // t.Method (without ())
OCAP, // cap
OCLOSE, // close
OCLOSURE, // f = func() { etc }
OITAB, // itable word of an interface value.
OCLOSUREVAR, // variable reference at beginning of closure function
OCFUNC, // reference to c function pointer (not go func value)
+ OCHECKNOTNIL, // emit code to ensure pointer/interface not nil
// arch-specific registers
OREGISTER, // a register, such as AX.
void closurehdr(Node *ntype);
void typecheckclosure(Node *func, int top);
Node* walkclosure(Node *func, NodeList **init);
-void walkcallclosure(Node *n, NodeList **init);
+void typecheckpartialcall(Node*, Node*);
+Node* walkpartialcall(Node*, NodeList**);
/*
* const.c
int anyregalloc(void);
void betypeinit(void);
void bgen(Node *n, int true, int likely, Prog *to);
-void checkref(Node*);
+void checkref(Node *n, int force);
+void checknotnil(Node*, NodeList**);
void cgen(Node*, Node*);
void cgen_asop(Node *n);
void cgen_call(Node *n, int proc);
}
case OCLOSURE:
- // TODO do them here (or earlier) instead of in walkcallclosure,
+ // TODO do them here (or earlier),
// so escape analysis can avoid more heapmoves.
return;
}
}
return 0;
}
+
+void
+checknotnil(Node *x, NodeList **init)
+{
+ Node *n;
+
+ if(isinter(x->type)) {
+ x = nod(OITAB, x, N);
+ typecheck(&x, Erv);
+ }
+ n = nod(OCHECKNOTNIL, x, N);
+ n->typecheck = 1;
+ *init = list(*init, n);
+}
yyerror("rhs of . must be a name"); // impossible
goto error;
}
+ r = n->right;
if(n->left->op == OTYPE) {
if(!looktypedot(n, t, 0)) {
switch(n->op) {
case ODOTINTER:
case ODOTMETH:
- ok |= Ecall;
+ if(top&Ecall)
+ ok |= Ecall;
+ else {
+ typecheckpartialcall(n, r);
+ ok |= Erv;
+ }
break;
default:
ok |= Erv;
yyerror("%N is not a type", n);
goto error;
}
- if((ok & Ecall) && !(top & Ecall)) {
- yyerror("method %N is not an expression, must be called", n);
- goto error;
- }
// TODO(rsc): simplify
if((top & (Ecall|Erv|Etype)) && !(top & Etop) && !(ok & (Erv|Etype|Ecall))) {
yyerror("%N used as value", n);
// fall through
case OIND:
case ODOTPTR:
+ case OCLOSUREVAR:
return 1;
case ODOT:
return islvalue(n->left);
case OLABEL:
case ODCLCONST:
case ODCLTYPE:
+ case OCHECKNOTNIL:
break;
case OBLOCK:
case OIMAG:
case ODOTMETH:
case ODOTINTER:
+ walkexpr(&n->left, init);
+ goto ret;
+
case OIND:
+ if(n->left->type->type->width == 0) {
+ n->left = cheapexpr(n->left, init);
+ checknotnil(n->left, init);
+ }
walkexpr(&n->left, init);
goto ret;
case ODOT:
+ usefield(n);
+ walkexpr(&n->left, init);
+ goto ret;
+
case ODOTPTR:
usefield(n);
+ if(n->op == ODOTPTR && n->left->type->type->width == 0) {
+ n->left = cheapexpr(n->left, init);
+ checknotnil(n->left, init);
+ }
walkexpr(&n->left, init);
goto ret;
if(n->list && n->list->n->op == OAS)
goto ret;
- /*
- if(n->left->op == OCLOSURE) {
- walkcallclosure(n, init);
- t = n->left->type;
- }
- */
-
walkexpr(&n->left, init);
walkexprlist(n->list, init);
case OCLOSURE:
n = walkclosure(n, init);
goto ret;
+
+ case OCALLPART:
+ n = walkpartialcall(n, init);
+ goto ret;
}
fatal("missing switch %O", n->op);
--- /dev/null
+// run
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+// Concrete types implementing M method.
+// Smaller than a word, word-sized, larger than a word.
+// Value and pointer receivers.
+
+type Tinter interface {
+ M(int, byte) (byte, int)
+}
+
+type Tsmallv byte
+
+func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x+int(v) }
+
+type Tsmallp byte
+
+func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x+int(*p) }
+
+type Twordv uintptr
+
+func (v Twordv) M(x int, b byte) (byte, int) { return b, x+int(v) }
+
+type Twordp uintptr
+
+func (p *Twordp) M(x int, b byte) (byte, int) { return b, x+int(*p) }
+
+type Tbigv [2]uintptr
+
+func (v Tbigv) M(x int, b byte) (byte, int) { return b, x+int(v[0])+int(v[1]) }
+
+type Tbigp [2]uintptr
+
+func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x+int(p[0])+int(p[1]) }
+
+// Again, with an unexported method.
+
+type tsmallv byte
+
+func (v tsmallv) m(x int, b byte) (byte, int) { return b, x+int(v) }
+
+type tsmallp byte
+
+func (p *tsmallp) m(x int, b byte) (byte, int) { return b, x+int(*p) }
+
+type twordv uintptr
+
+func (v twordv) m(x int, b byte) (byte, int) { return b, x+int(v) }
+
+type twordp uintptr
+
+func (p *twordp) m(x int, b byte) (byte, int) { return b, x+int(*p) }
+
+type tbigv [2]uintptr
+
+func (v tbigv) m(x int, b byte) (byte, int) { return b, x+int(v[0])+int(v[1]) }
+
+type tbigp [2]uintptr
+
+func (p *tbigp) m(x int, b byte) (byte, int) { return b, x+int(p[0])+int(p[1]) }
+
+type tinter interface {
+ m(int, byte) (byte, int)
+}
+
+// Embedding via pointer.
+
+type T1 struct {
+ T2
+}
+
+type T2 struct {
+ *T3
+}
+
+type T3 struct {
+ *T4
+}
+
+type T4 struct {
+}
+
+func (t4 T4) M(x int, b byte) (byte, int) { return b, x+40 }
+
+var failed = false
+
+func CheckI(name string, i Tinter, inc int) {
+ b, x := i.M(1000, 99)
+ if b != 99 || x != 1000+inc {
+ failed = true
+ print(name, ".M(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n")
+ }
+
+ CheckF("(i="+name+")", i.M, inc)
+}
+
+func CheckF(name string, f func(int, byte) (byte, int), inc int) {
+ b, x := f(1000, 99)
+ if b != 99 || x != 1000+inc {
+ failed = true
+ print(name, "(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n")
+ }
+}
+
+func checkI(name string, i tinter, inc int) {
+ b, x := i.m(1000, 99)
+ if b != 99 || x != 1000+inc {
+ failed = true
+ print(name, ".m(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n")
+ }
+
+ checkF("(i="+name+")", i.m, inc)
+}
+
+func checkF(name string, f func(int, byte) (byte, int), inc int) {
+ b, x := f(1000, 99)
+ if b != 99 || x != 1000+inc {
+ failed = true
+ print(name, "(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n")
+ }
+}
+
+func shouldPanic(f func()) {
+ defer func() {
+ if recover() == nil {
+ panic("not panicking")
+ }
+ }()
+ f()
+}
+
+func shouldNotPanic(f func()) {
+ f()
+}
+
+func main() {
+ sv := Tsmallv(1)
+ CheckI("sv", sv, 1)
+ CheckF("sv.M", sv.M, 1)
+ CheckF("(&sv).M", (&sv).M, 1)
+ psv := &sv
+ CheckI("psv", psv, 1)
+ CheckF("psv.M", psv.M, 1)
+ CheckF("(*psv).M", (*psv).M, 1)
+
+ sp := Tsmallp(2)
+ CheckI("&sp", &sp, 2)
+ CheckF("sp.M", sp.M, 2)
+ CheckF("(&sp).M", (&sp).M, 2)
+ psp := &sp
+ CheckI("psp", psp, 2)
+ CheckF("psp.M", psp.M, 2)
+ CheckF("(*psp).M", (*psp).M, 2)
+
+ wv := Twordv(3)
+ CheckI("wv", wv, 3)
+ CheckF("wv.M", wv.M, 3)
+ CheckF("(&wv).M", (&wv).M, 3)
+ pwv := &wv
+ CheckI("pwv", pwv, 3)
+ CheckF("pwv.M", pwv.M, 3)
+ CheckF("(*pwv).M", (*pwv).M, 3)
+
+ wp := Twordp(4)
+ CheckI("&wp", &wp, 4)
+ CheckF("wp.M", wp.M, 4)
+ CheckF("(&wp).M", (&wp).M, 4)
+ pwp := &wp
+ CheckI("pwp", pwp, 4)
+ CheckF("pwp.M", pwp.M, 4)
+ CheckF("(*pwp).M", (*pwp).M, 4)
+
+ bv := Tbigv([2]uintptr{5, 6})
+ pbv := &bv
+ CheckI("bv", bv, 11)
+ CheckF("bv.M", bv.M, 11)
+ CheckF("(&bv).M", (&bv).M, 11)
+ CheckI("pbv", pbv, 11)
+ CheckF("pbv.M", pbv.M, 11)
+ CheckF("(*pbv).M", (*pbv).M, 11)
+
+ bp := Tbigp([2]uintptr{7,8})
+ CheckI("&bp", &bp, 15)
+ CheckF("bp.M", bp.M, 15)
+ CheckF("(&bp).M", (&bp).M, 15)
+ pbp := &bp
+ CheckI("pbp", pbp, 15)
+ CheckF("pbp.M", pbp.M, 15)
+ CheckF("(*pbp).M", (*pbp).M, 15)
+
+ _sv := tsmallv(1)
+ checkI("_sv", _sv, 1)
+ checkF("_sv.m", _sv.m, 1)
+ checkF("(&_sv).m", (&_sv).m, 1)
+ _psv := &_sv
+ checkI("_psv", _psv, 1)
+ checkF("_psv.m", _psv.m, 1)
+ checkF("(*_psv).m", (*_psv).m, 1)
+
+ _sp := tsmallp(2)
+ checkI("&_sp", &_sp, 2)
+ checkF("_sp.m", _sp.m, 2)
+ checkF("(&_sp).m", (&_sp).m, 2)
+ _psp := &_sp
+ checkI("_psp", _psp, 2)
+ checkF("_psp.m", _psp.m, 2)
+ checkF("(*_psp).m", (*_psp).m, 2)
+
+ _wv := twordv(3)
+ checkI("_wv", _wv, 3)
+ checkF("_wv.m", _wv.m, 3)
+ checkF("(&_wv).m", (&_wv).m, 3)
+ _pwv := &_wv
+ checkI("_pwv", _pwv, 3)
+ checkF("_pwv.m", _pwv.m, 3)
+ checkF("(*_pwv).m", (*_pwv).m, 3)
+
+ _wp := twordp(4)
+ checkI("&_wp", &_wp, 4)
+ checkF("_wp.m", _wp.m, 4)
+ checkF("(&_wp).m", (&_wp).m, 4)
+ _pwp := &_wp
+ checkI("_pwp", _pwp, 4)
+ checkF("_pwp.m", _pwp.m, 4)
+ checkF("(*_pwp).m", (*_pwp).m, 4)
+
+ _bv := tbigv([2]uintptr{5, 6})
+ _pbv := &_bv
+ checkI("_bv", _bv, 11)
+ checkF("_bv.m", _bv.m, 11)
+ checkF("(&_bv).m", (&_bv).m, 11)
+ checkI("_pbv", _pbv, 11)
+ checkF("_pbv.m", _pbv.m, 11)
+ checkF("(*_pbv).m", (*_pbv).m, 11)
+
+ _bp := tbigp([2]uintptr{7,8})
+ checkI("&_bp", &_bp, 15)
+ checkF("_bp.m", _bp.m, 15)
+ checkF("(&_bp).m", (&_bp).m, 15)
+ _pbp := &_bp
+ checkI("_pbp", _pbp, 15)
+ checkF("_pbp.m", _pbp.m, 15)
+ checkF("(*_pbp).m", (*_pbp).m, 15)
+
+ t4 := T4{}
+ t3 := T3{&t4}
+ t2 := T2{&t3}
+ t1 := T1{t2}
+ CheckI("t4", t4, 40)
+ CheckI("&t4", &t4, 40)
+ CheckI("t3", t3, 40)
+ CheckI("&t3", &t3, 40)
+ CheckI("t2", t2, 40)
+ CheckI("&t2", &t2, 40)
+ CheckI("t1", t1, 40)
+ CheckI("&t1", &t1, 40)
+
+ // x.M panics if x is an interface type and is nil,
+ // or if x.M expands to (*x).M where x is nil,
+ // or if x.M expands to x.y.z.w.M where something
+ // along the evaluation of x.y.z.w is nil.
+ var f func(int, byte) (byte, int)
+ shouldPanic(func() { psv = nil; f = psv.M })
+ shouldPanic(func() { pwv = nil; f = pwv.M })
+ shouldPanic(func() { pbv = nil; f = pbv.M })
+ shouldPanic(func() { var i Tinter; f = i.M })
+ shouldPanic(func() { _psv = nil; f = _psv.m })
+ shouldPanic(func() { _pwv = nil; f = _pwv.m })
+ shouldPanic(func() { _pbv = nil; f = _pbv.m })
+ shouldPanic(func() { var _i tinter; f = _i.m })
+ shouldPanic(func() { var t1 T1; f = t1.M })
+ shouldPanic(func() { var t2 T2; f = t2.M })
+ shouldPanic(func() { var t3 *T3; f = t3.M })
+ shouldPanic(func() { var t3 T3; f = t3.M })
+
+ if f != nil {
+ panic("something set f")
+ }
+
+ // x.M does not panic if x is a nil pointer and
+ // M is a method with a pointer receiver.
+ shouldNotPanic(func() { psp = nil; f = psp.M })
+ shouldNotPanic(func() { pwp = nil; f = pwp.M })
+ shouldNotPanic(func() { pbp = nil; f = pbp.M })
+ shouldNotPanic(func() { _psp = nil; f = _psp.m })
+ shouldNotPanic(func() { _pwp = nil; f = _pwp.m })
+ shouldNotPanic(func() { _pbp = nil; f = _pbp.m })
+ shouldNotPanic(func() { var t4 T4; f = t4.M })
+ if f == nil {
+ panic("nothing set f")
+ }
+}