ref: e686640da8441d0cae0e45d5d6ef9f96c45a8e24
dir: /mi/match.c/
#include <stdlib.h> #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 "parse.h" #include "mi.h" typedef struct Dtree Dtree; struct Dtree { /* If the values are equal, go to 'sub'. If 'val' is null, anything matches. */ Node *patexpr; /* the full pattern for this node */ Node **val; /* pattern values to compare against */ size_t nval; Node **load; /* expression value being compared */ size_t nload; Dtree **sub; /* submatch to use if if equal */ size_t nsub; Dtree *any; /* tree for a wildcard match. */ /* captured variables and action */ Node **cap; size_t ncap; Node *act; int id; }; static Dtree *addpat(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap); void dtdump(Dtree *dt, FILE *f); /* We treat all integer types, boolean types, etc, as having 2^n constructors. * * since, of course, we can't represent all of the constructors for 64 bit * integers using 64 bit values, we just approximate it. We'd have failed (run * out of memory, etc) long before getting to this code if we actually had that * many branches of the switch statements anyways. */ static size_t nconstructors(Type *t) { if (!t) return 0; t = tybase(t); switch (t->type) { case Tyvoid: return 0; 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 Tylong: return ~0ull; 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 Tyulong: return ~0ull; 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 Tyfunc: return 0; 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: die("Invalid constructor type %s in match", tystr(t)); break; } return 0; } static int ndt; static Dtree *mkdtree() { Dtree *t; t = zalloc(sizeof(Dtree)); t->id = ndt++; return t; } static Dtree *addwild(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { if (t->any) return t->any; t->any = mkdtree(); t->any->patexpr = pat; lappend(cap, ncap, pat); return t->any; } static Dtree *addunion(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { Dtree *sub; size_t i; if (t->any) return t->any; /* if we have the value already... */ sub = NULL; for (i = 0; i < t->nval; i++) { if (nameeq(t->val[i], pat->expr.args[0])) { if (pat->expr.nargs > 1) return addpat(t->sub[i], pat->expr.args[1], NULL, cap, ncap); else return t->sub[i]; } } sub = mkdtree(); sub->patexpr = pat; lappend(&t->val, &t->nval, pat->expr.args[0]); lappend(&t->sub, &t->nsub, sub); if (pat->expr.nargs == 2) sub = addpat(sub, pat->expr.args[1], NULL, cap, ncap); return sub; } static Dtree *addlit(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { Dtree *sub; size_t i; if (t->any) return t->any; for (i = 0; i < t->nval; i++) { if (liteq(t->val[i]->expr.args[0], pat->expr.args[0])) return t->sub[i]; } sub = mkdtree(); sub->patexpr = pat; lappend(&t->val, &t->nval, pat); lappend(&t->sub, &t->nsub, sub); return sub; } static Dtree *addtup(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { size_t i; if (t->any) return t->any; for (i = 0; i < pat->expr.nargs; i++) t = addpat(t, pat->expr.args[i], NULL, cap, ncap); return t; } static Dtree *addarr(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { size_t i; if (t->any) return t->any; for (i = 0; i < pat->expr.nargs; i++) t = addpat(t, pat->expr.args[i], NULL, cap, ncap); return t; } static Dtree *addstruct(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { Node *elt; size_t i, j; if (t->any) return t->any; for (i = 0; i < pat->expr.nargs; i++) { elt = pat->expr.args[i]; for (j = 0; j < t->nval; j++) { if (!strcmp(namestr(elt->expr.idx), namestr(t->val[j]->expr.idx))) t = addpat(t, pat->expr.args[i], NULL, cap, ncap); break; } } return t; } static Dtree *addpat(Dtree *t, Node *pat, Node *val, Node ***cap, size_t *ncap) { Dtree *ret; Node *dcl; if (pat == NULL) return t; switch (exprop(pat)) { case Ovar: dcl = decls[pat->expr.did]; if (dcl->decl.isconst) ret = addpat(t, dcl->decl.init, val, cap, ncap); else ret = addwild(t, pat, val, cap, ncap); break; case Oucon: ret = addunion(t, pat, val, cap, ncap); break; case Olit: ret = addlit(t, pat, val, cap, ncap); break; case Otup: ret = addtup(t, pat, val, cap, ncap); break; case Oarr: ret = addarr(t, pat, val, cap, ncap); break; case Ostruct: ret = addstruct(t, pat, val, cap, ncap); break; default: ret = NULL; fatal(pat, "unsupported pattern %s of type %s", opstr[exprop(pat)], tystr(exprtype(pat))); break; } return ret; } static int isexhaustive(Dtree *dt) { Type *subt; size_t i; if (dt->any) return 1; if (dt->nsub > 0) { subt = tybase(exprtype(dt->sub[0]->patexpr)); if (dt->nsub != nconstructors(subt)) return 0; } switch (exprop(dt->patexpr)) { case Ovar: return 1; case Olit: return 1; case Oucon: for (i = 0; i < dt->nsub; i++) if (!isexhaustive(dt->sub[i])) return 0; return 1; break; case Otup: for (i = 0; i < dt->nsub; i++) if (!isexhaustive(dt->sub[i])) return 0; return 1; break; case Oarr: for (i = 0; i < dt->nsub; i++) if (!isexhaustive(dt->sub[i])) return 0; return 1; break; case Ostruct: for (i = 0; i < dt->nsub; i++) if (!isexhaustive(dt->sub[i])) return 0; return 1; break; default: die("Invalid pattern in exhaustivenes check. BUG."); break; } return 0; } static int exhaustivematch(Node *m, Dtree *t, Type *tt) { size_t i; if (t->any) return 1; if (t->nsub != nconstructors(tt)) return 0; for (i = 0; i < t->nsub; i++) if (!isexhaustive(t->sub[i])) return 0; return 1; } static Node *genmatch(Dtree *dt) { return NULL; } Node *gensimpmatch(Node *m) { Dtree *t, *leaf; Node **pat, **cap; size_t npat, ncap; size_t i; pat = m->matchstmt.matches; npat = m->matchstmt.nmatches; t = mkdtree(); for (i = 0; i < npat; i++) { cap = NULL; ncap = 0; leaf = addpat(t, pat[i]->match.pat, NULL, &cap, &ncap); /* TODO: NULL is returned by unsupported patterns. */ if (!leaf) return NULL; if (leaf->act) fatal(pat[i], "pattern matched by earlier case on line %d", leaf->act->loc.line); leaf->act = pat[i]->match.block; leaf->cap = cap; leaf->ncap = ncap; } if (!exhaustivematch(m, t, exprtype(m->matchstmt.val))) fatal(m, "nonexhaustive pattern set in match statement"); return genmatch(t); } char *dtnodestr(Node *n) { switch (exprop(n)) { case Ovar: return namestr(n->expr.args[0]); case Olit: return litstr[n->expr.args[0]->lit.littype]; case Oucon: return namestr(n->expr.args[0]); case Otup: return "tuple"; case Oarr: return "array"; case Ostruct: return "struct"; default: die("Invalid pattern in exhaustivenes check. BUG."); break; } return "???"; } void dtdumpnode(Dtree *dt, FILE *f, int depth, int iswild) { Node *e; size_t i; if (dt->patexpr) { e = dt->patexpr; indentf(depth, "%s%s %s : %s\n", iswild ? "WILDCARD " : "", opstr[exprop(e)], dtnodestr(e), tystr(exprtype(e))); } if (dt->cap) for (i = 0; i < dt->ncap; i++) indentf(depth + 1, "capture %s\n", dtnodestr(dt->cap[i])); if (dt->act) indentf(depth + 1, "action\n"); for (i = 0; i < dt->nsub; i++) dtdumpnode(dt->sub[i], f, depth + 1, 0); if (dt->any) dtdumpnode(dt->any, f, depth + 1, 1); } void dtdump(Dtree *dt, FILE *f) { dtdumpnode(dt, f, 0, 0); }