ref: a16c4e637079bb3d7f1cb93ae9b2348d710c003f
dir: /parse/specialize.c/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <inttypes.h>
#include <ctype.h>
#include <string.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "parse.h"
static Node *specializenode(Node *g, Htab *tsmap);
void addtraits(Type *t, Bitset *traits)
{
size_t b;
if (traits)
for (b = 0; bsiter(traits, &b); b++)
settrait(t, traittab[b]);
}
/*
* Duplicates the type 't', with all bound type
* parameters substituted with the substitions
* described in 'tsmap'
*
* Returns a fresh type with all unbound type
* parameters (type schemes in most literature)
* replaced with type variables that we can unify
* against */
Type *tyspecialize(Type *t, Htab *tsmap, Htab *delayed)
{
Type *ret, *tmp, **arg;
size_t i, narg;
t = tysearch(t);
if (hthas(tsmap, t))
return htget(tsmap, t);
switch (t->type) {
case Typaram:
ret = mktyvar(t->loc);
addtraits(ret, t->traits);
htput(tsmap, t, ret);
break;
case Tygeneric:
ret = mktyname(t->loc, t->name, tyspecialize(t->sub[0], tsmap, delayed));
ret->issynth = 1;
htput(tsmap, t, ret);
for (i = 0; i < t->ngparam; i++)
lappend(&ret->arg, &ret->narg, tyspecialize(t->gparam[i], tsmap, delayed));
break;
case Tyname:
arg = NULL;
narg = 0;
for (i = 0; i < t->narg; i++)
lappend(&arg, &narg, tyspecialize(t->arg[i], tsmap, delayed));
ret = mktyname(t->loc, t->name, tyspecialize(t->sub[0], tsmap, delayed));
ret->arg = arg;
ret->narg = narg;
break;
case Tystruct:
ret = tydup(t);
htput(tsmap, t, ret);
pushstab(NULL);
for (i = 0; i < t->nmemb; i++)
ret->sdecls[i] = specializenode(t->sdecls[i], tsmap);
popstab();
break;
case Tyunion:
ret = tydup(t);
htput(tsmap, t, ret);
for (i = 0; i < t->nmemb; i++) {
tmp = NULL;
if (ret->udecls[i]->etype)
tmp = tyspecialize(t->udecls[i]->etype, tsmap, delayed);
ret->udecls[i] = mkucon(t->loc, t->udecls[i]->name, ret, tmp);
ret->udecls[i]->utype = ret;
ret->udecls[i]->id = i;
ret->udecls[i]->synth = 1;
}
break;
case Tyvar:
if (delayed && hthas(delayed, t)) {
ret = tydup(t);
tmp = htget(delayed, t);
htput(delayed, ret, tyspecialize(tmp, tsmap, delayed));
} else {
ret = t;
}
break;
default:
if (t->nsub > 0) {
ret = tydup(t);
htput(tsmap, t, ret);
for (i = 0; i < t->nsub; i++)
ret->sub[i] = tyspecialize(t->sub[i], tsmap, delayed);
} else {
ret = t;
}
break;
}
return ret;
}
/* Checks if the type 't' is generic, and if it is
* substitutes the types. This is here for efficiency,
* so we don't gratuitously duplicate types */
static Type *tysubst(Type *t, Htab *tsmap)
{
if (hasparams(t))
return tyspecialize(t, tsmap, NULL);
else
return t;
}
/*
* Fills the substitution map with a mapping from
* the type parameter 'from' to it's substititon 'to'
*/
static void fillsubst(Htab *tsmap, Type *to, Type *from)
{
size_t i;
if (from->type == Typaram) {
if (debugopt['S'])
printf("mapping %s => %s\n", tystr(from), tystr(to));
htput(tsmap, from, to);
return;
}
assert(to->nsub == from->nsub);
for (i = 0; i < to->nsub; i++)
fillsubst(tsmap, to->sub[i], from->sub[i]);
if (to->type == Tyname && to->narg > 0) {
for (i = 0; i < to->narg; i++)
fillsubst(tsmap, to->arg[i], from->arg[i]);
}
}
/*
* Fixes up nodes. This involves fixing up the
* declaration identifiers once we specialize
*/
static void fixup(Node *n)
{
size_t i;
Node *d;
Stab *ns;
if (!n)
return;
switch (n->type) {
case Nfile:
case Nuse:
die("Node %s not allowed here\n", nodestr[n->type]);
break;
case Nexpr:
fixup(n->expr.idx);
for (i = 0; i < n->expr.nargs; i++)
fixup(n->expr.args[i]);
if (n->expr.op == Ovar) {
ns = curstab();
if (n->expr.args[0]->name.ns)
ns = getns_str(ns, n->expr.args[0]->name.ns);
if (!ns)
fatal(n, "No namespace %s\n", n->expr.args[0]->name.ns);
d = getdcl(ns, n->expr.args[0]);
if (!d)
die("Missing decl %s", namestr(n->expr.args[0]));
if (d->decl.isgeneric)
d = specializedcl(d, n->expr.type, &n->expr.args[0]);
n->expr.did = d->decl.did;
}
break;
case Nlit:
switch (n->lit.littype) {
case Lfunc: fixup(n->lit.fnval); break;
case Lchr: case Lint: case Lflt:
case Lstr: case Llbl: case Lbool:
break;
}
break;
case Nifstmt:
fixup(n->ifstmt.cond);
fixup(n->ifstmt.iftrue);
fixup(n->ifstmt.iffalse);
break;
case Nloopstmt:
fixup(n->loopstmt.init);
fixup(n->loopstmt.cond);
fixup(n->loopstmt.step);
fixup(n->loopstmt.body);
break;
case Niterstmt:
fixup(n->iterstmt.elt);
fixup(n->iterstmt.seq);
fixup(n->iterstmt.body);
break;
case Nmatchstmt:
fixup(n->matchstmt.val);
for (i = 0; i < n->matchstmt.nmatches; i++)
fixup(n->matchstmt.matches[i]);
break;
case Nmatch:
/* patterns are evaluated in their block's scope */
pushstab(n->match.block->block.scope);
fixup(n->match.pat);
popstab();
fixup(n->match.block);
break;
case Nblock:
pushstab(n->block.scope);
for (i = 0; i < n->block.nstmts; i++)
fixup(n->block.stmts[i]);
popstab();
break;
case Ndecl:
fixup(n->decl.init);
break;
case Nfunc:
pushstab(n->func.scope);
fixup(n->func.body);
popstab();
break;
case Nnone: case Nname:
break;
case Nimpl:
die("trait/impl not implemented");
break;
}
}
/*
* Duplicates a node, replacing all things that
* need to be specialized to make it concrete
* instead of generic, and returns it.
*/
static Node *specializenode(Node *n, Htab *tsmap)
{
Node *r;
size_t i;
if (!n)
return NULL;
r = mknode(n->loc, n->type);
switch (n->type) {
case Nfile:
case Nuse:
die("Node %s not allowed here\n", nodestr[n->type]);
break;
case Nexpr:
r->expr.op = n->expr.op;
r->expr.type = tysubst(n->expr.type, tsmap);
r->expr.isconst = n->expr.isconst;
r->expr.nargs = n->expr.nargs;
r->expr.idx = specializenode(n->expr.idx, tsmap);
r->expr.args = xalloc(n->expr.nargs * sizeof(Node*));
for (i = 0; i < n->expr.nargs; i++)
r->expr.args[i] = specializenode(n->expr.args[i], tsmap);
break;
case Nname:
if (n->name.ns)
r->name.ns = strdup(n->name.ns);
r->name.name = strdup(n->name.name);
break;
case Nlit:
r->lit.littype = n->lit.littype;
r->lit.type = tysubst(n->expr.type, tsmap);
switch (n->lit.littype) {
case Lchr: r->lit.chrval = n->lit.chrval; break;
case Lint: r->lit.intval = n->lit.intval; break;
case Lflt: r->lit.fltval = n->lit.fltval; break;
case Lstr: r->lit.strval = n->lit.strval; break;
case Llbl: r->lit.lblval = n->lit.lblval; break;
case Lbool: r->lit.boolval = n->lit.boolval; break;
case Lfunc: r->lit.fnval = specializenode(n->lit.fnval, tsmap); break;
}
break;
case Nifstmt:
r->ifstmt.cond = specializenode(n->ifstmt.cond, tsmap);
r->ifstmt.iftrue = specializenode(n->ifstmt.iftrue, tsmap);
r->ifstmt.iffalse = specializenode(n->ifstmt.iffalse, tsmap);
break;
case Nloopstmt:
r->loopstmt.init = specializenode(n->loopstmt.init, tsmap);
r->loopstmt.cond = specializenode(n->loopstmt.cond, tsmap);
r->loopstmt.step = specializenode(n->loopstmt.step, tsmap);
r->loopstmt.body = specializenode(n->loopstmt.body, tsmap);
break;
case Niterstmt:
r->iterstmt.elt = specializenode(n->iterstmt.elt, tsmap);
r->iterstmt.seq = specializenode(n->iterstmt.seq, tsmap);
r->iterstmt.body = specializenode(n->iterstmt.body, tsmap);
break;
case Nmatchstmt:
r->matchstmt.val = specializenode(n->matchstmt.val, tsmap);
r->matchstmt.nmatches = n->matchstmt.nmatches;
r->matchstmt.matches = xalloc(n->matchstmt.nmatches * sizeof(Node*));
for (i = 0; i < n->matchstmt.nmatches; i++)
r->matchstmt.matches[i] = specializenode(n->matchstmt.matches[i], tsmap);
break;
case Nmatch:
r->match.pat = specializenode(n->match.pat, tsmap);
r->match.block = specializenode(n->match.block, tsmap);
break;
case Nblock:
r->block.scope = mkstab();
r->block.scope->super = curstab();
pushstab(r->block.scope);
r->block.nstmts = n->block.nstmts;
r->block.stmts = xalloc(sizeof(Node *)*n->block.nstmts);
for (i = 0; i < n->block.nstmts; i++)
r->block.stmts[i] = specializenode(n->block.stmts[i], tsmap);
popstab();
break;
case Ndecl:
r->decl.did = ndecls;
/* sym */
r->decl.name = specializenode(n->decl.name, tsmap);
r->decl.type = tysubst(n->decl.type, tsmap);
/* symflags */
r->decl.isconst = n->decl.isconst;
r->decl.isgeneric = n->decl.isgeneric;
r->decl.isextern = n->decl.isextern;
r->decl.isglobl = n->decl.isglobl;
if (curstab())
putdcl(curstab(), r);
/* init */
r->decl.init = specializenode(n->decl.init, tsmap);
lappend(&decls, &ndecls, r);
break;
case Nfunc:
r->func.scope = mkstab();
r->func.scope->super = curstab();
pushstab(r->func.scope);
r->func.type = tysubst(n->func.type, tsmap);
r->func.nargs = n->func.nargs;
r->func.args = xalloc(sizeof(Node *)*n->func.nargs);
for (i = 0; i < n->func.nargs; i++)
r->func.args[i] = specializenode(n->func.args[i], tsmap);
r->func.body = specializenode(n->func.body, tsmap);
popstab();
break;
case Nimpl:
die("trait/impl not implemented");
case Nnone:
die("Nnone should not be seen as node type!");
break;
}
return r;
}
Node *genericname(Node *n, Type *t)
{
char buf[1024];
char *p;
char *end;
Node *name;
if (!n->decl.isgeneric)
return n->decl.name;
p = buf;
end = buf + sizeof buf;
p += snprintf(p, end - p, "%s", n->decl.name->name.name);
p += snprintf(p, end - p, "$");
p += tyidfmt(p, end - p, t);
name = mkname(n->loc, buf);
if (n->decl.name->name.ns)
setns(name, n->decl.name->name.ns);
return name;
}
/*
* Takes a generic declaration, and creates a specialized
* duplicate of it with type 'to'. It also generates
* a name for this specialized node, and returns it in '*name'.
*/
Node *specializedcl(Node *g, Type *to, Node **name)
{
extern int stabstkoff;
Node *d, *n;
Htab *tsmap;
Stab *st;
assert(g->type == Ndecl);
assert(g->decl.isgeneric);
n = genericname(g, to);
*name = n;
if (n->name.ns)
st = getns_str(curstab(), n->name.ns);
else
st = file->file.globls;
if (!st)
fatal(n, "Can't find symbol table for %s.%s", n->name.ns, n->name.name);
d = getdcl(st, n);
if (debugopt['S'])
printf("depth[%d] specializing [%d]%s => %s\n", stabstkoff, g->loc.line, namestr(g->decl.name), namestr(n));
if (d)
return d;
if (g->decl.trait) {
printf("%s\n", namestr(n));
fatal(g, "No trait implemented for for %s:%s", namestr(g->decl.name), tystr(to));
}
/* namespaced names need to be looked up in their correct
* context. */
if (n->name.ns)
pushstab(st);
/* specialize */
tsmap = mkht(tyhash, tyeq);
fillsubst(tsmap, to, g->decl.type);
d = mkdecl(g->loc, n, tysubst(g->decl.type, tsmap));
d->decl.isconst = g->decl.isconst;
d->decl.isextern = g->decl.isextern;
d->decl.isglobl = g->decl.isglobl;
d->decl.init = specializenode(g->decl.init, tsmap);
putdcl(st, d);
fixup(d);
lappend(&file->file.stmts, &file->file.nstmts, d);
if (d->decl.name->name.ns)
popstab();
return d;
}