// makeaddable returns a node whose memory location is the
// same as n, but which is addressable in the Go language
// sense.
// This is different from functions like cheapexpr that may make
// a copy of their argument.
static void
makeaddable(Node *n)
{
// The arguments to uintptraddr technically have an address but
// may not be addressable in the Go sense: for example, in the case
// of T(v).Field where T is a struct type and v is
// an addressable value.
switch(n->op) {
case OINDEX:
if(isfixedarray(n->left->type))
makeaddable(n->left);
break;
case ODOT:
case OXDOT:
// Turn T(v).Field into v.Field
if(n->left->op == OCONVNOP)
n->left = n->left->left;
makeaddable(n->left);
break;
case ODOTPTR:
default:
// nothing to do
break;
}
}
// basenod returns the simplest child node of n pointing to the same
// memory area.
static Node*
basenod(Node *n)
{
for(;;) {
if(n->op == ODOT || n->op == OXDOT || n->op == OCONVNOP || n->op == OCONV || n->op == OPAREN) {
n = n->left;
continue;
}
if(n->op == OINDEX && isfixedarray(n->type)) {
n = n->left;
continue;
}
break;
}
return n;
}
static int
callinstr(Node **np, NodeList **init, int wr, int skip)
{
Node *f, *b, *n;
Type *t;
int class, hascalls;
n = *np;
//print("callinstr for %+N [ %O ] etype=%E class=%d\n",
// n, n->op, n->type ? n->type->etype : -1, n->class);
if(skip || n->type == T || n->type->etype >= TIDEAL)
return 0;
t = n->type;
if(isartificial(n))
return 0;
b = basenod(n);
// it skips e.g. stores to ... parameter array
if(isartificial(b))
return 0;
class = b->class;
// BUG: we _may_ want to instrument PAUTO sometimes
// e.g. if we've got a local variable/method receiver
// that has got a pointer inside. Whether it points to
// the heap or not is impossible to know at compile time
if((class&PHEAP) || class == PPARAMREF || class == PEXTERN
|| b->op == OINDEX || b->op == ODOTPTR || b->op == OIND || b->op == OXDOT) {
hascalls = 0;
foreach(n, hascallspred, &hascalls);
if(hascalls) {
n = detachexpr(n, init);
*np = n;
}
n = treecopy(n);
makeaddable(n);
if(t->etype == TSTRUCT || isfixedarray(t)) {
f = mkcall(wr ? "racewriterange" : "racereadrange", T, init, uintptraddr(n),
nodintconst(t->width));
} else
f = mkcall(wr ? "racewrite" : "raceread", T, init, uintptraddr(n));
*init = list(*init, f);
return 1;
}
return 0;
}
/*
* type check switch statement
*/
void
typecheckswitch(Node *n)
{
int top, lno, ptr;
char *nilonly;
Type *t, *badtype, *missing, *have;
NodeList *l, *ll;
Node *ncase, *nvar;
Node *def;
lno = lineno;
typechecklist(n->ninit, Etop);
nilonly = nil;
if(n->ntest != N && n->ntest->op == OTYPESW) {
// type switch
top = Etype;
typecheck(&n->ntest->right, Erv);
t = n->ntest->right->type;
if(t != T && t->etype != TINTER)
yyerror("cannot type switch on non-interface value %lN", n->ntest->right);
} else {
// value switch
top = Erv;
if(n->ntest) {
typecheck(&n->ntest, Erv);
defaultlit(&n->ntest, T);
t = n->ntest->type;
} else
t = types[TBOOL];
if(t) {
if(!okforeq[t->etype])
yyerror("cannot switch on %lN", n->ntest);
else if(t->etype == TARRAY && !isfixedarray(t))
nilonly = "slice";
else if(t->etype == TARRAY && isfixedarray(t) && algtype1(t, nil) == ANOEQ)
yyerror("cannot switch on %lN", n->ntest);
else if(t->etype == TSTRUCT && algtype1(t, &badtype) == ANOEQ)
yyerror("cannot switch on %lN (struct containing %T cannot be compared)", n->ntest, badtype);
else if(t->etype == TFUNC)
nilonly = "func";
else if(t->etype == TMAP)
nilonly = "map";
}
}
n->type = t;
def = N;
for(l=n->list; l; l=l->next) {
ncase = l->n;
setlineno(n);
if(ncase->list == nil) {
// default
if(def != N)
yyerror("multiple defaults in switch (first at %L)", def->lineno);
else
def = ncase;
} else {
for(ll=ncase->list; ll; ll=ll->next) {
setlineno(ll->n);
typecheck(&ll->n, Erv | Etype);
if(ll->n->type == T || t == T)
continue;
setlineno(ncase);
switch(top) {
case Erv: // expression switch
defaultlit(&ll->n, t);
if(ll->n->op == OTYPE)
yyerror("type %T is not an expression", ll->n->type);
else if(ll->n->type != T && !assignop(ll->n->type, t, nil) && !assignop(t, ll->n->type, nil)) {
if(n->ntest)
yyerror("invalid case %N in switch on %N (mismatched types %T and %T)", ll->n, n->ntest, ll->n->type, t);
else
yyerror("invalid case %N in switch (mismatched types %T and bool)", ll->n, ll->n->type);
} else if(nilonly && !isconst(ll->n, CTNIL)) {
yyerror("invalid case %N in switch (can only compare %s %N to nil)", ll->n, nilonly, n->ntest);
}
break;
case Etype: // type switch
if(ll->n->op == OLITERAL && istype(ll->n->type, TNIL)) {
;
} else if(ll->n->op != OTYPE && ll->n->type != T) { // should this be ||?
yyerror("%lN is not a type", ll->n);
// reset to original type
ll->n = n->ntest->right;
} else if(ll->n->type->etype != TINTER && t->etype == TINTER && !implements(ll->n->type, t, &missing, &have, &ptr)) {
if(have && !missing->broke && !have->broke)
yyerror("impossible type switch case: %lN cannot have dynamic type %T"
" (wrong type for %S method)\n\thave %S%hT\n\twant %S%hT",
n->ntest->right, ll->n->type, missing->sym, have->sym, have->type,
missing->sym, missing->type);
else if(!missing->broke)
yyerror("impossible type switch case: %lN cannot have dynamic type %T"
" (missing %S method)", n->ntest->right, ll->n->type, missing->sym);
}
break;
}
}
}
if(top == Etype && n->type != T) {
ll = ncase->list;
nvar = ncase->nname;
if(nvar != N) {
if(ll && ll->next == nil && ll->n->type != T && !istype(ll->n->type, TNIL)) {
// single entry type switch
nvar->ntype = typenod(ll->n->type);
} else {
// multiple entry type switch or default
nvar->ntype = typenod(n->type);
}
}
}
typechecklist(ncase->nbody, Etop);
}
lineno = lno;
}
void
typecheckrange(Node *n)
{
char *why;
Type *t, *t1, *t2;
Node *v1, *v2;
NodeList *ll;
// delicate little dance. see typecheckas2
for(ll=n->list; ll; ll=ll->next)
if(ll->n->defn != n)
typecheck(&ll->n, Erv | Easgn);
typecheck(&n->right, Erv);
if((t = n->right->type) == T)
goto out;
if(isptr[t->etype] && isfixedarray(t->type))
t = t->type;
n->type = t;
switch(t->etype) {
default:
yyerror("cannot range over %lN", n->right);
goto out;
case TARRAY:
t1 = types[TINT];
t2 = t->type;
break;
case TMAP:
t1 = t->down;
t2 = t->type;
break;
case TCHAN:
if(!(t->chan & Crecv)) {
yyerror("invalid operation: range %N (receive from send-only type %T)", n->right, n->right->type);
goto out;
}
t1 = t->type;
t2 = nil;
if(count(n->list) == 2)
goto toomany;
break;
case TSTRING:
t1 = types[TINT];
t2 = runetype;
break;
}
if(count(n->list) > 2) {
toomany:
yyerror("too many variables in range");
}
v1 = n->list->n;
v2 = N;
if(n->list->next)
v2 = n->list->next->n;
if(v1->defn == n)
v1->type = t1;
else if(v1->type != T && assignop(t1, v1->type, &why) == 0)
yyerror("cannot assign type %T to %lN in range%s", t1, v1, why);
if(v2) {
if(v2->defn == n)
v2->type = t2;
else if(v2->type != T && assignop(t2, v2->type, &why) == 0)
yyerror("cannot assign type %T to %lN in range%s", t2, v2, why);
}
out:
typechecklist(n->nbody, Etop);
// second half of dance
n->typecheck = 1;
for(ll=n->list; ll; ll=ll->next)
if(ll->n->typecheck == 0)
typecheck(&ll->n, Erv | Easgn);
}
// walkexpr and walkstmt combined
// walks the tree and adds calls to the
// instrumentation code to top-level (statement) nodes' init
static void
racewalknode(Node **np, NodeList **init, int wr, int skip)
{
Node *n, *n1;
NodeList *l;
NodeList *fini;
n = *np;
if(n == N)
return;
if(debug['w'] > 1)
dump("racewalk-before", n);
setlineno(n);
if(init == nil)
fatal("racewalk: bad init list");
if(init == &n->ninit) {
// If init == &n->ninit and n->ninit is non-nil,
// racewalknode might append it to itself.
// nil it out and handle it separately before putting it back.
l = n->ninit;
n->ninit = nil;
racewalklist(l, nil);
racewalknode(&n, &l, wr, skip); // recurse with nil n->ninit
appendinit(&n, l);
*np = n;
return;
}
racewalklist(n->ninit, nil);
switch(n->op) {
default:
fatal("racewalk: unknown node type %O", n->op);
case OASOP:
case OAS:
case OAS2:
case OAS2RECV:
case OAS2FUNC:
case OAS2MAPR:
racewalknode(&n->left, init, 1, 0);
racewalknode(&n->right, init, 0, 0);
goto ret;
case OCFUNC:
case OVARKILL:
// can't matter
goto ret;
case OBLOCK:
if(n->list == nil)
goto ret;
switch(n->list->n->op) {
case OCALLFUNC:
case OCALLMETH:
case OCALLINTER:
// Blocks are used for multiple return function calls.
// x, y := f() becomes BLOCK{CALL f, AS x [SP+0], AS y [SP+n]}
// We don't want to instrument between the statements because it will
// smash the results.
racewalknode(&n->list->n, &n->list->n->ninit, 0, 0);
fini = nil;
racewalklist(n->list->next, &fini);
n->list = concat(n->list, fini);
break;
default:
// Ordinary block, for loop initialization or inlined bodies.
racewalklist(n->list, nil);
break;
}
goto ret;
case ODEFER:
racewalknode(&n->left, init, 0, 0);
goto ret;
case OPROC:
racewalknode(&n->left, init, 0, 0);
goto ret;
case OCALLINTER:
racewalknode(&n->left, init, 0, 0);
goto ret;
case OCALLFUNC:
// Instrument dst argument of runtime.writebarrier* calls
// as we do not instrument runtime code.
if(n->left->sym != S && n->left->sym->pkg == runtimepkg && strncmp(n->left->sym->name, "writebarrier", 12) == 0) {
// Find the dst argument.
// The list can be reordered, so it's not necessary just the first or the second element.
for(l = n->list; l; l = l->next) {
if(strcmp(n->left->sym->name, "writebarrierfat") == 0) {
if(l->n->left->xoffset == widthptr)
break;
} else {
if(l->n->left->xoffset == 0)
break;
}
}
if(l == nil)
fatal("racewalk: writebarrier no arg");
if(l->n->right->op != OADDR)
fatal("racewalk: writebarrier bad arg");
callinstr(&l->n->right->left, init, 1, 0);
}
racewalknode(&n->left, init, 0, 0);
goto ret;
case ONOT:
case OMINUS:
case OPLUS:
case OREAL:
case OIMAG:
case OCOM:
racewalknode(&n->left, init, wr, 0);
goto ret;
case ODOTINTER:
racewalknode(&n->left, init, 0, 0);
goto ret;
case ODOT:
racewalknode(&n->left, init, 0, 1);
callinstr(&n, init, wr, skip);
goto ret;
case ODOTPTR: // dst = (*x).f with implicit *; otherwise it's ODOT+OIND
racewalknode(&n->left, init, 0, 0);
callinstr(&n, init, wr, skip);
goto ret;
case OIND: // *p
racewalknode(&n->left, init, 0, 0);
callinstr(&n, init, wr, skip);
goto ret;
case OSPTR:
case OLEN:
case OCAP:
racewalknode(&n->left, init, 0, 0);
if(istype(n->left->type, TMAP)) {
n1 = nod(OCONVNOP, n->left, N);
n1->type = ptrto(types[TUINT8]);
n1 = nod(OIND, n1, N);
typecheck(&n1, Erv);
callinstr(&n1, init, 0, skip);
}
goto ret;
case OLSH:
case ORSH:
case OLROT:
case OAND:
case OANDNOT:
case OOR:
case OXOR:
case OSUB:
case OMUL:
case OHMUL:
case OEQ:
case ONE:
case OLT:
case OLE:
case OGE:
case OGT:
case OADD:
case OCOMPLEX:
racewalknode(&n->left, init, wr, 0);
racewalknode(&n->right, init, wr, 0);
goto ret;
case OANDAND:
case OOROR:
racewalknode(&n->left, init, wr, 0);
// walk has ensured the node has moved to a location where
// side effects are safe.
// n->right may not be executed,
// so instrumentation goes to n->right->ninit, not init.
racewalknode(&n->right, &n->right->ninit, wr, 0);
goto ret;
case ONAME:
callinstr(&n, init, wr, skip);
goto ret;
case OCONV:
racewalknode(&n->left, init, wr, 0);
goto ret;
case OCONVNOP:
racewalknode(&n->left, init, wr, 0);
goto ret;
case ODIV:
case OMOD:
racewalknode(&n->left, init, wr, 0);
racewalknode(&n->right, init, wr, 0);
goto ret;
case OINDEX:
if(!isfixedarray(n->left->type))
racewalknode(&n->left, init, 0, 0);
else if(!islvalue(n->left)) {
// index of unaddressable array, like Map[k][i].
racewalknode(&n->left, init, wr, 0);
racewalknode(&n->right, init, 0, 0);
goto ret;
}
racewalknode(&n->right, init, 0, 0);
if(n->left->type->etype != TSTRING)
callinstr(&n, init, wr, skip);
goto ret;
case OSLICE:
case OSLICEARR:
case OSLICE3:
case OSLICE3ARR:
// Seems to only lead to double instrumentation.
//racewalknode(&n->left, init, 0, 0);
goto ret;
case OADDR:
racewalknode(&n->left, init, 0, 1);
goto ret;
case OEFACE:
racewalknode(&n->left, init, 0, 0);
racewalknode(&n->right, init, 0, 0);
goto ret;
case OITAB:
racewalknode(&n->left, init, 0, 0);
goto ret;
// should not appear in AST by now
case OSEND:
case ORECV:
case OCLOSE:
case ONEW:
case OXCASE:
case OXFALL:
case OCASE:
case OPANIC:
case ORECOVER:
case OCONVIFACE:
case OCMPIFACE:
case OMAKECHAN:
case OMAKEMAP:
case OMAKESLICE:
case OCALL:
case OCOPY:
case OAPPEND:
case ORUNESTR:
case OARRAYBYTESTR:
case OARRAYRUNESTR:
case OSTRARRAYBYTE:
case OSTRARRAYRUNE:
case OINDEXMAP: // lowered to call
case OCMPSTR:
case OADDSTR:
case ODOTTYPE:
case ODOTTYPE2:
case OAS2DOTTYPE:
case OCALLPART: // lowered to PTRLIT
case OCLOSURE: // lowered to PTRLIT
case ORANGE: // lowered to ordinary for loop
case OARRAYLIT: // lowered to assignments
case OMAPLIT:
case OSTRUCTLIT:
yyerror("racewalk: %O must be lowered by now", n->op);
goto ret;
// impossible nodes: only appear in backend.
case ORROTC:
case OEXTEND:
yyerror("racewalk: %O cannot exist now", n->op);
goto ret;
// just do generic traversal
case OFOR:
case OIF:
case OCALLMETH:
case ORETURN:
case ORETJMP:
case OSWITCH:
case OSELECT:
case OEMPTY:
case OBREAK:
case OCONTINUE:
case OFALL:
case OGOTO:
case OLABEL:
goto ret;
// does not require instrumentation
case OPRINT: // don't bother instrumenting it
case OPRINTN: // don't bother instrumenting it
case OCHECKNIL: // always followed by a read.
case OPARAM: // it appears only in fn->exit to copy heap params back
case OCLOSUREVAR:// immutable pointer to captured variable
case ODOTMETH: // either part of CALLMETH or CALLPART (lowered to PTRLIT)
case OINDREG: // at this stage, only n(SP) nodes from nodarg
case ODCL: // declarations (without value) cannot be races
case ODCLCONST:
case ODCLTYPE:
case OTYPE:
case ONONAME:
case OLITERAL:
case OSLICESTR: // always preceded by bounds checking, avoid double instrumentation.
case OTYPESW: // ignored by code generation, do not instrument.
goto ret;
}
ret:
if(n->op != OBLOCK) // OBLOCK is handled above in a special way.
racewalklist(n->list, init);
if(n->ntest != N)
racewalknode(&n->ntest, &n->ntest->ninit, 0, 0);
if(n->nincr != N)
racewalknode(&n->nincr, &n->nincr->ninit, 0, 0);
racewalklist(n->nbody, nil);
racewalklist(n->nelse, nil);
racewalklist(n->rlist, nil);
*np = n;
}