mirror of
https://github.com/golang/go
synced 2024-11-22 07:34:40 -07:00
6g: new interface rules (code got simpler!)
R=ken OCL=28374 CL=28378
This commit is contained in:
Russ Cox
parent
d76f095750
commit
a6ba5ec535
@ -129,7 +129,6 @@ updatetype(Type *n, Type *t)
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n->sym = s;
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n->local = local;
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n->siggen = 0;
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n->methptr = 0;
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n->printed = 0;
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n->method = nil;
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n->vargen = 0;
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@ -293,7 +292,7 @@ addmethod(Node *n, Type *t, int local)
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if(pa == T)
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goto bad;
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f = dclmethod(pa);
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f = methtype(pa);
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if(f == T)
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goto bad;
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@ -137,7 +137,6 @@ struct Type
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uchar chan;
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uchar recur; // to detect loops
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uchar trecur; // to detect loops
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uchar methptr; // 1=direct 2=pointer
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uchar printed;
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uchar embedded; // TFIELD embedded type
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uchar siggen;
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@ -725,9 +724,7 @@ int isinter(Type*);
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int isnilinter(Type*);
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int isddd(Type*);
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Type* maptype(Type*, Type*);
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Type* dclmethod(Type*);
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Type* methtype(Type*);
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int methconv(Type*);
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Sym* signame(Type*);
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int eqtype(Type*, Type*, int);
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int eqtypenoname(Type*, Type*);
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@ -787,10 +784,8 @@ int lookdot0(Sym*, Type*, Type**);
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Type* lookdot1(Sym*, Type*, Type*);
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int adddot1(Sym*, Type*, int, Type**);
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Node* adddot(Node*);
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void expand0(Type*);
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void expand1(Type*, int);
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void expandmeth(Sym*, Type*);
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void genptrtramp(Sym*, Sym*, Type*, Type*, Sym*, Type*);
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void genwrapper(Type*, Type*, Sym*);
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/*
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* dcl.c
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@ -140,6 +140,12 @@ ieeedtod(uint64 *ieee, double native)
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*ieee = ((uint64)h << 32) | l;
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}
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static int
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sigcmp(Sig *a, Sig *b)
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{
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return strcmp(a->name, b->name);
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}
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/*
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* Add DATA for signature s.
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* progt - type in program
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@ -165,13 +171,6 @@ ieeedtod(uint64 *ieee, double native)
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* } meth[1]; // one or more - last name is nil
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* };
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*/
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static int
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sigcmp(Sig *a, Sig *b)
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{
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return strcmp(a->name, b->name);
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}
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void
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dumpsigt(Type *progt, Type *ifacet, Type *rcvrt, Type *methodt, Sym *s)
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{
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@ -180,12 +179,16 @@ dumpsigt(Type *progt, Type *ifacet, Type *rcvrt, Type *methodt, Sym *s)
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Sig *a, *b;
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char buf[NSYMB];
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Type *this;
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Iter savet;
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Prog *oldlist;
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Sym *method;
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uint32 sighash;
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int ot;
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if(debug['r']) {
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print("dumpsigt progt=%T ifacet=%T rcvrt=%T methodt=%T s=%S\n",
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progt, ifacet, rcvrt, methodt, s);
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}
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a = nil;
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o = 0;
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oldlist = nil;
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@ -201,6 +204,16 @@ dumpsigt(Type *progt, Type *ifacet, Type *rcvrt, Type *methodt, Sym *s)
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if(method == nil)
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continue;
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// get receiver type for this particular method.
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this = getthisx(f->type)->type->type;
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if(f->embedded != 2 && isptr[this->etype] && !isptr[progt->etype]) {
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// pointer receiver method but value method set.
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// ignore.
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if(debug['r'])
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print("ignore %T for %T\n", f, progt);
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continue;
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}
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b = mal(sizeof(*b));
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b->link = a;
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a = b;
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@ -216,31 +229,19 @@ dumpsigt(Type *progt, Type *ifacet, Type *rcvrt, Type *methodt, Sym *s)
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if(!a->sym->siggen) {
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a->sym->siggen = 1;
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// TODO(rsc): This test is still not quite right.
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this = structfirst(&savet, getthis(f->type))->type;
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if(isptr[this->etype] != isptr[ifacet->etype]) {
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if(!eqtype(this, ifacet, 0)) {
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if(oldlist == nil)
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oldlist = pc;
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// indirect vs direct mismatch
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Sym *oldname, *newname;
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Type *oldthis, *newthis;
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newthis = ifacet;
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if(isptr[newthis->etype])
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oldthis = ifacet->type;
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// It would be okay to call genwrapper here always,
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// but we can generate more efficient code
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// using genembedtramp if all that is necessary
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// is a pointer adjustment and a JMP.
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if(f->embedded && isptr[ifacet->etype])
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genembedtramp(ifacet, a);
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else
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oldthis = ptrto(ifacet);
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newname = a->sym;
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oldname = methodsym(method, oldthis);
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genptrtramp(method, oldname, oldthis, f->type, newname, newthis);
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} else
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if(f->embedded) {
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// TODO(rsc): only works for pointer receivers
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if(oldlist == nil)
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oldlist = pc;
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genembedtramp(ifacet, a);
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genwrapper(ifacet, f, a->sym);
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}
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}
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o++;
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@ -449,23 +450,17 @@ dumpsignatures(void)
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rcvrt = t;
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// if there's a pointer, methods are on base.
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if(isptr[methodt->etype] && methodt->type->sym != S) {
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methodt = methodt->type;
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methodt = methtype(progt);
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if(methodt == T) {
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// if that failed, go back to progt,
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// assuming we're writing out a signature
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// for a type with no methods
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methodt = progt;
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} else {
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expandmeth(methodt->sym, methodt);
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// if methodt had a name, we don't want to see
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// it in the method names that go into the sigt.
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// e.g., if
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// type item *rat
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// then item needs its own sigt distinct from *rat,
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// but it needs to have all of *rat's methods, using
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// the *rat (not item) in the method names.
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if(rcvrt->sym != S)
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rcvrt = ptrto(methodt);
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}
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// and if ifacet is too wide, the methods
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// will see a pointer anyway.
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// if ifacet is too wide, the methods will see a pointer.
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if(ifacet->width > 8) {
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ifacet = ptrto(progt);
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rcvrt = ptrto(progt);
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@ -473,7 +468,7 @@ dumpsignatures(void)
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// don't emit non-trivial signatures for types defined outside this file.
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// non-trivial signatures might also drag in generated trampolines,
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// and ar can't handle duplicates of the trampolines.
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// and ar can't handle duplicate functions.
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// only pay attention to types with symbols, because
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// the ... structs and maybe other internal structs
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// don't get marked as local.
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@ -1495,7 +1495,7 @@ isddd(Type *t)
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* return type to hang methods off (r).
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*/
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Type*
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dclmethod(Type *t)
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methtype(Type *t)
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{
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int ptr;
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@ -1517,15 +1517,6 @@ dclmethod(Type *t)
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if(t->sym == S)
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return T;
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// check that all method receivers are consistent
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if(t->methptr != 0 && t->methptr != (1<<ptr)) {
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if(t->methptr != 3) {
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t->methptr = 3;
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yyerror("methods on both %T and *%T", t, t);
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}
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}
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t->methptr |= 1<<ptr;
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// check types
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if(!issimple[t->etype])
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switch(t->etype) {
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@ -1543,50 +1534,6 @@ dclmethod(Type *t)
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return t;
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}
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/*
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* this is dclmethod() without side effects.
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*/
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Type*
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methtype(Type *t)
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{
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if(t == T)
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return T;
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if(isptr[t->etype]) {
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if(t->sym != S)
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return T;
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t = t->type;
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}
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if(t == T || t->etype == TINTER || t->sym == S)
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return T;
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return t;
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}
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/*
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* given type t in a method call, returns op
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* to convert t into appropriate receiver.
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* returns OADDR if t==x and method takes *x
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* returns OIND if t==*x and method takes x
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*/
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int
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methconv(Type *t)
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{
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Type *m;
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m = methtype(t);
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if(m == T)
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return 0;
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if(m->methptr&2) {
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// want pointer
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if(t == m)
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return OADDR;
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return 0;
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}
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// want non-pointer
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if(t != m)
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return OIND;
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return 0;
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}
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int
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iscomposite(Type *t)
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{
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@ -2604,19 +2551,22 @@ struct Symlink
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{
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Type* field;
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uchar good;
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uchar followptr;
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Symlink* link;
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};
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static Symlink* slist;
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void
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expand0(Type *t)
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static void
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expand0(Type *t, int followptr)
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{
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Type *f, *u;
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Symlink *sl;
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u = t;
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if(isptr[u->etype])
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if(isptr[u->etype]) {
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followptr = 1;
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u = u->type;
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}
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u = methtype(t);
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if(u != T) {
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@ -2629,13 +2579,14 @@ expand0(Type *t)
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sl = mal(sizeof(*sl));
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sl->field = f;
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sl->link = slist;
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sl->followptr = followptr;
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slist = sl;
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}
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}
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}
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void
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expand1(Type *t, int d)
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static void
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expand1(Type *t, int d, int followptr)
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{
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Type *f, *u;
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@ -2646,11 +2597,13 @@ expand1(Type *t, int d)
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t->trecur = 1;
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if(d != nelem(dotlist)-1)
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expand0(t);
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expand0(t, followptr);
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u = t;
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if(isptr[u->etype])
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if(isptr[u->etype]) {
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followptr = 1;
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u = u->type;
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}
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if(u->etype != TSTRUCT && u->etype != TINTER)
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goto out;
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@ -2659,7 +2612,7 @@ expand1(Type *t, int d)
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continue;
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if(f->sym == S)
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continue;
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expand1(f->type, d-1);
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expand1(f->type, d-1, followptr);
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}
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out:
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@ -2682,7 +2635,7 @@ expandmeth(Sym *s, Type *t)
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// generate all reachable methods
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slist = nil;
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expand1(t, nelem(dotlist)-1);
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expand1(t, nelem(dotlist)-1, 0);
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// check each method to be uniquely reachable
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for(sl=slist; sl!=nil; sl=sl->link) {
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@ -2704,7 +2657,8 @@ expandmeth(Sym *s, Type *t)
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f = typ(TFIELD);
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*f = *sl->field;
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f->embedded = 1; // needs a trampoline
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if(sl->followptr)
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f->embedded = 2;
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f->down = t->method;
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t->method = f;
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@ -2742,43 +2696,46 @@ structargs(Type **tl, int mustname)
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}
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/*
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* Generate a trampoline to convert
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* from an indirect receiver to a direct receiver
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* or vice versa.
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* Generate a wrapper function to convert from
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* a receiver of type T to a receiver of type U.
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* That is,
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*
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* method - short name of method (Len)
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* oldname - old mangled method name (x·y·Len)
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* oldthis - old this type (y)
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* oldtype - type of method being called;
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* only in and out params are known okay,
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* receiver might be != oldthis.
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* newnam [sic] - new mangled method name (x·*y·Len)
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* newthis - new this type (*y)
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* func (t T) M() {
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* ...
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* }
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*
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* already exists; this function generates
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*
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* func (u U) M() {
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* u.M()
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* }
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*
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* where the types T and U are such that u.M() is valid
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* and calls the T.M method.
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* The resulting function is for use in method tables.
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*
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* rcvrtype - U
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* method - M func (t T)(), a TFIELD type struct
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* newnam - the eventual mangled name of this function
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*/
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void
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genptrtramp(Sym *method, Sym *oldname, Type *oldthis, Type *oldtype, Sym *newnam, Type *newthis)
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genwrapper(Type *rcvrtype, Type *method, Sym *newnam)
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{
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Node *fn, *args, *l, *in, *call, *out, *this, *rcvr, *meth;
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Node *this, *in, *out, *fn, *args, *call;
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Node *l;
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Iter savel;
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if(debug['r']) {
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print("\ngenptrtramp method=%S oldname=%S oldthis=%T\n",
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method, oldname, oldthis);
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print("\toldtype=%T newnam=%S newthis=%T\n",
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oldtype, newnam, newthis);
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print("genwrapper rcvrtype=%T method=%T newnam=%S\n",
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rcvrtype, method, newnam);
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}
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dclcontext = PEXTERN;
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markdcl();
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this = nametodcl(newname(lookup(".this")), newthis);
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in = structargs(getinarg(oldtype), 1);
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out = structargs(getoutarg(oldtype), 0);
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// fix up oldtype
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markdcl();
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oldtype = functype(nametodcl(newname(lookup(".this")), oldthis), in, out);
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popdcl();
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this = nametodcl(newname(lookup(".this")), rcvrtype);
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in = structargs(getinarg(method->type), 1);
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out = structargs(getoutarg(method->type), 0);
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fn = nod(ODCLFUNC, N, N);
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fn->nname = newname(newnam);
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@ -2791,19 +2748,10 @@ genptrtramp(Sym *method, Sym *oldname, Type *oldthis, Type *oldtype, Sym *newnam
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args = list(args, l->left);
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args = rev(args);
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// method to call
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if(isptr[oldthis->etype])
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rcvr = nod(OADDR, this->left, N);
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else
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rcvr = nod(OIND, this->left, N);
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gettype(rcvr, N);
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meth = nod(ODOTMETH, rcvr, newname(oldname));
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meth->xoffset = BADWIDTH; // TODO(rsc): necessary?
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meth->type = oldtype;
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call = nod(OCALL, meth, args);
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// generate call
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call = nod(OCALL, adddot(nod(ODOT, this->left, newname(method->sym))), args);
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fn->nbody = call;
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if(oldtype->outtuple > 0)
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if(method->type->outtuple > 0)
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fn->nbody = nod(ORETURN, call, N);
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if(debug['r'])
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@ -2850,11 +2798,13 @@ ifacecheck(Type *dst, Type *src, int lineno, int explicit)
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}
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Type*
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ifacelookdot(Sym *s, Type *t)
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ifacelookdot(Sym *s, Type *t, int *followptr)
|
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{
|
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int c, d;
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int i, c, d;
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Type *m;
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*followptr = 0;
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if(t == T)
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return T;
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@ -2864,8 +2814,15 @@ ifacelookdot(Sym *s, Type *t)
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yyerror("%T.%S is ambiguous", t, s);
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return T;
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}
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if(c == 1)
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if(c == 1) {
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for(i=0; i<d; i++) {
|
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if(isptr[dotlist[i].field->type->etype]) {
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*followptr = 1;
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break;
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}
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}
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return m;
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}
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}
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return T;
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}
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@ -2875,23 +2832,11 @@ ifacelookdot(Sym *s, Type *t)
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int
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ifaceokT2I(Type *t0, Type *iface, Type **m)
|
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{
|
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Type *t, *im, *tm;
|
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int imhash;
|
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Type *t, *im, *tm, *rcvr;
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int imhash, followptr;
|
||||
|
||||
t = methtype(t0);
|
||||
|
||||
// stopgap: check for
|
||||
// non-pointer type in T2I, methods want pointers.
|
||||
// supposed to do something better eventually
|
||||
// but this will catch errors while we decide the
|
||||
// details of the "better" solution.
|
||||
// only warn if iface is not interface{}.
|
||||
if(t == t0 && t->methptr == 2 && iface->type != T) {
|
||||
yyerror("probably wanted *%T not %T", t, t);
|
||||
*m = iface->type;
|
||||
return 0;
|
||||
}
|
||||
|
||||
// if this is too slow,
|
||||
// could sort these first
|
||||
// and then do one loop.
|
||||
@ -2905,11 +2850,20 @@ ifaceokT2I(Type *t0, Type *iface, Type **m)
|
||||
|
||||
for(im=iface->type; im; im=im->down) {
|
||||
imhash = typehash(im, 0, 0);
|
||||
tm = ifacelookdot(im->sym, t);
|
||||
tm = ifacelookdot(im->sym, t, &followptr);
|
||||
if(tm == T || typehash(tm, 0, 0) != imhash) {
|
||||
*m = im;
|
||||
return 0;
|
||||
}
|
||||
// if pointer receiver in method,
|
||||
// the method does not exist for value types.
|
||||
rcvr = getthisx(tm->type)->type->type;
|
||||
if(isptr[rcvr->etype] && !isptr[t0->etype] && !followptr) {
|
||||
if(debug['r'])
|
||||
yyerror("interface pointer mismatch");
|
||||
*m = im;
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
@ -1590,8 +1590,7 @@ lookdot1(Sym *s, Type *t, Type *f)
|
||||
int
|
||||
lookdot(Node *n, Type *t)
|
||||
{
|
||||
Type *f1, *f2, *tt;
|
||||
int op;
|
||||
Type *f1, *f2, *tt, *rcvr;
|
||||
Sym *s;
|
||||
|
||||
s = n->right->sym;
|
||||
@ -1618,18 +1617,19 @@ lookdot(Node *n, Type *t)
|
||||
|
||||
if(f2 != T) {
|
||||
tt = n->left->type;
|
||||
if((op = methconv(tt)) != 0) {
|
||||
switch(op) {
|
||||
case OADDR:
|
||||
rcvr = getthisx(f2->type)->type->type;
|
||||
if(!eqtype(rcvr, tt, 0)) {
|
||||
if(rcvr->etype == tptr && eqtype(rcvr->type, tt, 0)) {
|
||||
walktype(n->left, Elv);
|
||||
addrescapes(n->left);
|
||||
n->left = nod(OADDR, n->left, N);
|
||||
n->left->type = ptrto(tt);
|
||||
break;
|
||||
case OIND:
|
||||
} else if(tt->etype == tptr && eqtype(tt->type, rcvr, 0)) {
|
||||
n->left = nod(OIND, n->left, N);
|
||||
n->left->type = tt->type;
|
||||
break;
|
||||
} else {
|
||||
// method is attached to wrong type?
|
||||
fatal("method mismatch: %T for %T", rcvr, tt);
|
||||
}
|
||||
}
|
||||
n->right = methodname(n->right, n->left->type);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user