ref: dcd6fad70720c2c8baa5e0096f2b14e45e9aa447
dir: /mi/match.c/
#include <stdio.h>
#include <inttypes.h>
#include <stdarg.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 "util.h"
#include "parse.h"
#include "mi.h"
typedef struct Dtree Dtree;
struct Dtree {
int id;
Srcloc loc;
/* values for matching */
Node *lbl;
Node *load;
size_t nconstructors;
char accept;
char emitted;
char ptrwalk;
/* the decision tree step */
Node **pat;
size_t npat;
Dtree **next;
size_t nnext;
Dtree *any;
/* captured variables and action */
Node **cap;
size_t ncap;
};
Dtree *gendtree(Node *m, Node *val, Node **lbl, size_t nlbl);
static int addpat(Node *pat, Node *val,
Dtree *start, Dtree *accept,
Node ***cap, size_t *ncap,
Dtree ***end, size_t *nend);
void dtreedump(FILE *fd, Dtree *dt);
static Node *
utag(Node *n)
{
Node *tag;
tag = mkexpr(n->loc, Outag, n, NULL);
tag->expr.type = mktype(n->loc, Tyint32);
return tag;
}
static Node *
uvalue(Node *n, Type *ty)
{
Node *elt;
elt = mkexpr(n->loc, Oudata, n, NULL);
elt->expr.type = ty;
return elt;
}
static Node *
tupelt(Node *n, size_t i)
{
Node *idx, *elt;
idx = mkintlit(n->loc, i);
idx->expr.type = mktype(n->loc, Tyuint64);
elt = mkexpr(n->loc, Otupget, n, idx, NULL);
elt->expr.type = tybase(exprtype(n))->sub[i];
return elt;
}
static Node *
arrayelt(Node *n, size_t i)
{
Node *idx, *elt;
idx = mkintlit(n->loc, i);
idx->expr.type = mktype(n->loc, Tyuint64);
elt = mkexpr(n->loc, Oidx, n, idx, NULL);
elt->expr.type = tybase(exprtype(n))->sub[0];
return elt;
}
static Node *
findmemb(Node *pat, Node *name)
{
Node *n;
size_t i;
for (i = 0; i < pat->expr.nargs; i++) {
n = pat->expr.args[i];
if (nameeq(n->expr.idx, name))
return n;
}
return NULL;
}
static Dtree *
dtbytag(Dtree *t, Ucon *uc)
{
uint32_t tagval;
Node *taglit;
size_t i;
for (i = 0; i < t->npat; i++) {
taglit = t->pat[i]->expr.args[0];
tagval = taglit->lit.intval;
if (tagval == uc->id) {
return t->next[i];
}
}
return NULL;
}
static Node *
structmemb(Node *n, Node *name, Type *ty)
{
Node *elt;
elt = mkexpr(n->loc, Omemb, n, name, NULL);
elt->expr.type = ty;
return elt;
}
static Node *
addcapture(Node *n, Node **cap, size_t ncap)
{
Node **blk;
size_t nblk, i;
nblk = 0;
blk = NULL;
for (i = 0; i < ncap; i++)
lappend(&blk, &nblk, cap[i]);
for (i = 0; i < n->block.nstmts; i++)
lappend(&blk, &nblk, n->block.stmts[i]);
lfree(&n->block.stmts, &n->block.nstmts);
n->block.stmts = blk;
n->block.nstmts = nblk;
return n;
}
static Dtree *
mkdtree(Srcloc loc, Node *lbl)
{
static int ndtree;
Dtree *t;
t = zalloc(sizeof(Dtree));
t->lbl = lbl;
t->loc = loc;
t->id = ndtree++;
return t;
}
static Dtree *
nextnode(Srcloc loc, size_t idx, size_t count, Dtree *accept)
{
if (idx == count - 1)
return accept;
else
return mkdtree(loc, genlbl(loc));
}
static size_t
nconstructors(Type *t)
{
if (!t)
return 0;
t = tybase(t);
switch (t->type) {
case Tyvoid: return 1; break;
case Tybool: return 2; break;
case Tychar: return 0x10ffff; break;
/* signed ints */
case Tyint8: return 0x100; break;
case Tyint16: return 0x10000; break;
case Tyint32: return 0x100000000; break;
case Tyint: return 0x100000000; break;
case Tyint64: return ~0ull; break;
/* unsigned ints */
case Tybyte: return 0x100; break;
case Tyuint8: return 0x100; break;
case Tyuint16: return 0x10000; break;
case Tyuint32: return 0x100000000; break;
case Tyuint: return 0x100000000; break;
case Tyuint64: return ~0ull; break;
/* floats */
case Tyflt32: return ~0ull; break;
case Tyflt64: return ~0ull; break;
/* complex types */
case Typtr: return 1; break;
case Tyarray: return 1; break;
case Tytuple: return 1; break;
case Tystruct: return 1;
case Tyunion: return t->nmemb; break;
case Tyslice: return ~0ULL; break;
case Tyvar: case Typaram: case Tyunres: case Tyname:
case Tybad: case Tyvalist: case Tygeneric: case Ntypes:
case Tyfunc: case Tycode:
die("Invalid constructor type %s in match", tystr(t));
break;
}
return 0;
}
static int
verifymatch(Dtree *t)
{
size_t i;
int ret;
if (t->accept)
return 1;
ret = 0;
if (t->nnext == t->nconstructors || t->any)
ret = 1;
for (i = 0; i < t->nnext; i++)
if (!verifymatch(t->next[i]))
ret = 0;
return ret;
}
static int
acceptall(Dtree *t, Dtree *accept)
{
size_t i;
int ret;
if (t->accept || t->any == accept)
return 0;
ret = 0;
if (t->any) {
if (acceptall(t->any, accept))
ret = 1;
} else {
t->any = accept;
ret = 1;
}
for (i = 0; i < t->nnext; i++)
if (acceptall(t->next[i], accept))
ret = 1;
return ret;
}
static int
isnonrecursive(Dtree *dt, Type *ty)
{
if (istyprimitive(ty) || ty->type == Tyvoid || ty->type == Tyfunc || ty->type == Typtr)
return 1;
if (ty->type == Tystruct)
return ty->nmemb == 0;
if (ty->type == Tyarray)
return fold(ty->asize, 1)->expr.args[0]->lit.intval == 0;
return 0;
}
static int
addwildrec(Srcloc loc, Type *ty, Dtree *start, Dtree *accept, Dtree ***end, size_t *nend)
{
Dtree *next, **last, **tail;
size_t i, j, nelt, nlast, ntail;
Node *asize;
Ucon *uc;
int ret;
tail = NULL;
ntail = 0;
ty = tybase(ty);
if (ty->type == Typtr && start->any && start->any->ptrwalk) {
return addwildrec(loc, ty->sub[0], start->any, accept, end, nend);
} else if (isnonrecursive(start, ty)) {
if (start->accept || start == accept)
return 0;
for (i = 0; i < start->nnext; i++)
lappend(end, nend, start->next[i]);
if (start->any) {
lappend(end, nend, start->any);
return 0;
} else {
start->any = accept;
lappend(end, nend, accept);
return 1;
}
}
ret = 0;
last = NULL;
nlast = 0;
switch (ty->type) {
case Tytuple:
lappend(&last, &nlast, start);
for (i = 0; i < ty->nsub; i++) {
next = nextnode(loc, i, ty->nsub, accept);
tail = NULL;
ntail = 0;
for (j = 0; j < nlast; j++)
if (addwildrec(loc, ty->sub[i], last[j], next, &tail, &ntail))
ret = 1;
lfree(&last, &nlast);
last = tail;
nlast = ntail;
if (i == ty->nsub - 1)
break;
}
break;
case Tyarray:
lappend(&last, &nlast, start);
asize = fold(ty->asize, 1);
nelt = asize->expr.args[0]->lit.intval;
for (i = 0; i < nelt; i++) {
next = nextnode(loc, i, nelt, accept);
tail = NULL;
ntail = 0;
for (j = 0; j < nlast; j++)
if (addwildrec(loc, ty->sub[0], last[j], next, &tail, &ntail))
ret = 1;
lfree(&last, &nlast);
last = tail;
nlast = ntail;
if (i == nelt - 1)
break;
}
break;
case Tystruct:
lappend(&last, &nlast, start);
for (i = 0; i < ty->nmemb; i++) {
next = nextnode(loc, i, ty->nmemb, accept);
tail = NULL;
ntail = 0;
for (j = 0; j < nlast; j++)
if (addwildrec(loc, decltype(ty->sdecls[i]), last[j], next, &tail, &ntail))
ret = 1;
lfree(&last, &nlast);
last = tail;
nlast = ntail;
if (i == ty->nsub - 1)
break;
}
break;
case Tyunion:
for (i = 0; i < ty->nmemb; i++) {
uc = ty->udecls[i];
next = dtbytag(start, uc);
if (next) {
if (uc->etype) {
if (addwildrec(loc, uc->etype, next, accept, end, nend))
ret = 1;
} else {
lappend(end, nend, next);
}
}
}
if (!start->any) {
start->any = accept;
ret = 1;
}
lappend(&last, &nlast, accept);
break;
case Tyslice:
ret = acceptall(start, accept);
lappend(&last, &nlast, accept);
break;
default:
die("unreachable");
}
lcat(end, nend, last, nlast);
lfree(&last, &nlast);
return ret;
}
static int
addwild(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
Node *asn;
if (cap && ncap) {
asn = mkexpr(pat->loc, Oasn, pat, val, NULL);
asn->expr.type = exprtype(pat);
lappend(cap, ncap, asn);
}
return addwildrec(pat->loc, exprtype(pat), start, accept, end, nend);
}
static int
addunion(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
Node *tagid;
Dtree *next;
Ucon *uc;
if (start->any) {
lappend(end, nend, start->any);
return 0;
}
uc = finducon(tybase(exprtype(pat)), pat->expr.args[0]);
next = dtbytag(start, uc);
if (next) {
if (!uc->etype) {
lappend(end, nend, next);
return 0;
} else {
return addpat(pat->expr.args[1], uvalue(val, uc->etype), next, accept, cap, ncap, end, nend);
}
}
if (!start->load) {
start->load = utag(val);
start->nconstructors = nconstructors(tybase(exprtype(pat)));
}
tagid = mkintlit(pat->loc, uc->id);
tagid->expr.type = mktype(pat->loc, Tyint32);
lappend(&start->pat, &start->npat, tagid);
if (uc->etype) {
next = mkdtree(pat->loc, genlbl(pat->loc));
lappend(&start->next, &start->nnext, next);
addpat(pat->expr.args[1], uvalue(val, uc->etype), next, accept, cap, ncap, end, nend);
} else {
lappend(&start->next, &start->nnext, accept);
lappend(end, nend, accept);
}
return 1;
}
static int
addstr(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
Dtree **tail, **last, *next;
size_t i, j, n, ntail, nlast;
Node *p, *v, *lit;
Type *ty;
char *s;
int ret;
lit = pat->expr.args[0];
n = lit->lit.strval.len;
s = lit->lit.strval.buf;
ty = mktype(pat->loc, Tyuint64);
p = mkintlit(lit->loc, n);
v = structmemb(val, mkname(pat->loc, "len"), ty);
p->expr.type = ty;
if (n == 0)
next = accept;
else
next = mkdtree(pat->loc, genlbl(pat->loc));
last = NULL;
nlast = 0;
ret = 0;
if (addpat(p, v, start, next, cap, ncap, &last, &nlast))
ret = 1;
ty = mktype(pat->loc, Tybyte);
for (i = 0; i < n; i++) {
p = mkintlit(lit->loc, s[i]);
p->expr.type = ty;
v = arrayelt(val, i);
tail = NULL;
ntail = 0;
next = nextnode(pat->loc, i, n, accept);
for (j = 0; j < nlast; j++)
if (addpat(p, v, last[j], next, NULL, NULL, &tail, &ntail))
ret = 1;
lfree(&last, &nlast);
last = tail;
nlast = ntail;
}
lcat(end, nend, last, nlast);
lfree(&last, &nlast);
return ret;
}
static int
addlit(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
size_t i;
if (pat->expr.args[0]->lit.littype == Lstr) {
return addstr(pat, val, start, accept, cap, ncap, end, nend);
} else {
/* if we already have a match, we're not adding a new node */
if (start->any) {
lappend(end, nend, start->any);
return 0;
}
for (i = 0; i < start->npat; i++) {
if (liteq(start->pat[i]->expr.args[0], pat->expr.args[0])) {
lappend(end, nend, start->next[i]);
return 0;
}
}
/* wire up an edge from start to 'accept' */
if (!start->load) {
start->load = val;
start->nconstructors = nconstructors(exprtype(pat));
}
lappend(&start->pat, &start->npat, pat);
lappend(&start->next, &start->nnext, accept);
lappend(end, nend, accept);
return 1;
}
}
static int
addtup(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
size_t nargs, nlast, ntail, i, j;
Dtree *next, **last, **tail;
Node **args;
int ret;
args = pat->expr.args;
nargs = pat->expr.nargs;
last = NULL;
nlast = 0;
lappend(&last, &nlast, start);
ret = 0;
for (i = 0; i < nargs; i++) {
next = nextnode(args[i]->loc, i, nargs, accept);
tail = NULL;
ntail = 0;
for (j = 0; j < nlast; j++)
if (addpat(pat->expr.args[i], tupelt(val, i), last[j], next, cap, ncap, &tail, &ntail))
ret = 1;
lfree(&last, &nlast);
last = tail;
nlast = ntail;
}
lcat(end, nend, last, nlast);
lfree(&last, &nlast);
return ret;
}
static int
addarr(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
size_t nargs, nlast, ntail, i, j;
Dtree *next, **last, **tail;
Node **args;
int ret;
args = pat->expr.args;
nargs = pat->expr.nargs;
last = NULL;
nlast = 0;
lappend(&last, &nlast, start);
ret = 0;
for (i = 0; i < nargs; i++) {
next = nextnode(args[i]->loc, i, nargs, accept);
tail = NULL;
ntail = 0;
for (j = 0; j < nlast; j++)
if (addpat(pat->expr.args[i], arrayelt(val, i), last[j], next, cap, ncap, &tail, &ntail))
ret = 1;
lfree(&last, &nlast);
last = tail;
nlast = ntail;
}
lcat(end, nend, last, nlast);
lfree(&last, &nlast);
return ret;
}
static int
addstruct(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
Dtree *next, **last, **tail;
Node *memb, *name;
Type *ty, *mty;
size_t i, j, ntail, nlast;
int ret;
ret = 0;
last = NULL;
nlast = 0;
lappend(&last, &nlast, start);
ty = tybase(exprtype(pat));
for (i = 0; i < ty->nmemb; i++) {
mty = decltype(ty->sdecls[i]);
name = ty->sdecls[i]->decl.name;
memb = findmemb(pat, name);
next = nextnode(pat->loc, i, ty->nmemb, accept);
tail = NULL;
ntail = 0;
/* add a _ capture if we don't specify the value */
if (!memb) {
memb = mkexpr(ty->sdecls[i]->loc, Ogap, NULL);
memb->expr.type = mty;
}
for (j = 0; j < nlast; j++) {
if (addpat(memb, structmemb(val, name, mty), last[j], next, cap, ncap, &tail, &ntail))
ret = 1;
}
lfree(&last, &nlast);
last = tail;
nlast = ntail;
}
lcat(end, nend, last, nlast);
lfree(&last, &nlast);
return ret;
}
static int
addderefpat(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
Node *deref;
Dtree *walk;
deref = mkexpr(val->loc, Oderef, val, NULL);
deref->expr.type = exprtype(pat->expr.args[0]);
start->nconstructors = nconstructors(exprtype(deref));
if (start->any && !start->any->ptrwalk)
return 0;
else if (!start->any)
start->any = mkdtree(pat->loc, genlbl(pat->loc));
walk = start->any;
walk->ptrwalk = 1;
return addpat(pat->expr.args[0], deref, walk, accept, cap, ncap, end, nend);
}
static int
addpat(Node *pat, Node *val, Dtree *start, Dtree *accept, Node ***cap, size_t *ncap, Dtree ***end, size_t *nend)
{
int ret;
Node *dcl;
Type *ty;
pat = fold(pat, 1);
ret = 0;
switch (exprop(pat)) {
case Ovar:
dcl = decls[pat->expr.did];
if (dcl->decl.isconst) {
ty = decltype(dcl);
if (ty->type == Tyfunc || ty->type == Tycode || ty->type == Tyvalist)
fatal(dcl, "bad pattern %s:%s: unmatchable type", declname(dcl), tystr(ty));
if (!dcl->decl.init)
fatal(dcl, "bad pattern %s:%s: missing initializer", declname(dcl), tystr(ty));
ret = addpat(dcl->decl.init, val, start, accept, cap, ncap, end, nend);
} else {
ret = addwild(pat, val, start, accept, cap, ncap, end, nend);
}
break;
case Oucon:
ret = addunion(pat, val, start, accept, cap, ncap, end, nend);
break;
case Olit:
ret = addlit(pat, val, start, accept, cap, ncap, end, nend);
break;
case Otup:
ret = addtup(pat, val, start, accept, cap, ncap, end, nend);
break;
case Oarr:
ret = addarr(pat, val, start, accept, cap, ncap, end, nend);
break;
case Ostruct:
ret = addstruct(pat, val, start, accept, cap, ncap, end, nend);
break;
case Ogap:
ret = addwild(pat, NULL, start, accept, NULL, NULL, end, nend);
break;
case Oaddr:
ret = addderefpat(pat, val, start, accept, cap, ncap, end, nend);
break;
default:
fatal(pat, "unsupported pattern %s of type %s", opstr[exprop(pat)], tystr(exprtype(pat)));
break;
}
return ret;
}
/* val must be a pure, fully evaluated value */
Dtree *
gendtree(Node *m, Node *val, Node **lbl, size_t nlbl)
{
Dtree *start, *accept, **end;
Node **pat, **cap;
size_t npat, ncap, nend;
size_t i;
pat = m->matchstmt.matches;
npat = m->matchstmt.nmatches;
end = NULL;
nend = 0;
start = mkdtree(m->loc, genlbl(m->loc));
for (i = 0; i < npat; i++) {
cap = NULL;
ncap = 0;
accept = mkdtree(lbl[i]->loc, lbl[i]);
accept->accept = 1;
if (!addpat(pat[i]->match.pat, val, start, accept, &cap, &ncap, &end, &nend))
fatal(pat[i], "pattern matched by earlier case");
addcapture(pat[i]->match.block, cap, ncap);
}
if (!verifymatch(start))
fatal(m, "nonexhaustive pattern set in match statement");
return start;
}
void
genmatchcode(Dtree *dt, Node ***out, size_t *nout)
{
Node *jmp, *eq, *fail;
int emit;
size_t i;
if (dt->emitted)
return;
dt->emitted = 1;
/* the we jump to the accept label when generating the parent */
if (dt->accept) {
jmp = mkexpr(dt->loc, Ojmp, dt->lbl, NULL);
jmp->expr.type = mktype(dt->loc, Tyvoid);
lappend(out, nout, jmp);
return;
}
lappend(out, nout, dt->lbl);
for (i = 0; i < dt->nnext; i++) {
if (i == dt->nnext - 1 && dt->any) {
fail = dt->any->lbl;
emit = 0;
} else {
fail = genlbl(dt->loc);
emit = 1;
}
eq = mkexpr(dt->loc, Oeq, dt->load, dt->pat[i], NULL);
eq->expr.type = mktype(dt->loc, Tybool);
jmp = mkexpr(dt->loc, Ocjmp, eq, dt->next[i]->lbl, fail, NULL);
jmp->expr.type = mktype(dt->loc, Tyvoid);
lappend(out, nout, jmp);
genmatchcode(dt->next[i], out, nout);
if (emit)
lappend(out, nout, fail);
}
if (dt->any) {
jmp = mkexpr(dt->loc, Ojmp, dt->any->lbl, NULL);
jmp->expr.type = mktype(dt->loc, Tyvoid);
lappend(out, nout, jmp);
genmatchcode(dt->any, out, nout);
}
}
void
genonematch(Node *pat, Node *val, Node *iftrue, Node *iffalse, Node ***out, size_t *nout, Node ***cap, size_t *ncap)
{
Dtree *start, *accept, *reject, **end;
size_t nend;
end = NULL;
nend = 0;
start = mkdtree(pat->loc, genlbl(pat->loc));
accept = mkdtree(iftrue->loc, iftrue);
accept->accept = 1;
reject = mkdtree(iffalse->loc, iffalse);
reject->accept = 1;
assert(addpat(pat, val, start, accept, cap, ncap, &end, &nend));
acceptall(start, reject);
genmatchcode(start, out, nout);
}
void
genmatch(Node *m, Node *val, Node ***out, size_t *nout)
{
Node **pat, **lbl, *end, *endlbl;
size_t npat, nlbl, i;
Dtree *dt;
lbl = NULL;
nlbl = 0;
pat = m->matchstmt.matches;
npat = m->matchstmt.nmatches;
for (i = 0; i < npat; i++)
lappend(&lbl, &nlbl, genlbl(pat[i]->match.block->loc));
endlbl = genlbl(m->loc);
dt = gendtree(m, val, lbl, nlbl);
genmatchcode(dt, out, nout);
for (i = 0; i < npat; i++) {
end = mkexpr(pat[i]->loc, Ojmp, endlbl, NULL);
end->expr.type = mktype(end->loc, Tyvoid);
lappend(out, nout, lbl[i]);
lappend(out, nout, pat[i]->match.block);
lappend(out, nout, end);
}
lappend(out, nout, endlbl);
if (debugopt['m']) {
dtreedump(stdout, dt);
for (i = 0; i < *nout; i++)
dump((*out)[i], stdout);
}
}
void
dtreedumplit(FILE *fd, Dtree *dt, Node *n, size_t depth)
{
char *s;
s = lblstr(dt->lbl);
switch (n->lit.littype) {
case Lvoid: findentf(fd, depth, "%s: Lvoid\n"); break;
case Lchr: findentf(fd, depth, "%s: Lchr %c\n", s, n->lit.chrval); break;
case Lbool: findentf(fd, depth, "%s: Lbool %s\n", s, n->lit.boolval ? "true" : "false"); break;
case Lint: findentf(fd, depth, "%s: Lint %llu\n", s, n->lit.intval); break;
case Lflt: findentf(fd, depth, "%s: Lflt %lf\n", s, n->lit.fltval); break;
case Lstr: findentf(fd, depth, "%s: Lstr %.*s\n", s, (int)n->lit.strval.len, n->lit.strval.buf); break;
case Llbl: findentf(fd, depth, "%s: Llbl %s\n", s, n->lit.lblval); break;
case Lfunc: findentf(fd, depth, "%s: Lfunc\n"); break;
}
}
void
dtreedumpnode(FILE *fd, Dtree *dt, size_t depth)
{
size_t i;
if (dt->accept)
findentf(fd, depth, "%s: accept\n", lblstr(dt->lbl));
for (i = 0; i < dt->nnext; i++) {
dtreedumplit(fd, dt, dt->pat[i]->expr.args[0], depth);
dtreedumpnode(fd, dt->next[i], depth + 1);
}
if (dt->any) {
findentf(fd, depth, "%s: wildcard\n", lblstr(dt->lbl));
dtreedumpnode(fd, dt->any, depth + 1);
}
}
void
dtreedump(FILE *fd, Dtree *dt)
{
dtreedumpnode(fd, dt, 0);
}