import the Slacker's QVM code base

1 files changed, 671 insertions, 0 deletions

diff --git a/src/tools/lcc/lburg/lburg.c b/src/tools/lcc/lburg/lburg.c
new file mode 100644
index 0000000..c43c96a
--- /dev/null
+++ b/src/tools/lcc/lburg/lburg.c
@@ -0,0 +1,671 @@
+#include <assert.h>
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include "lburg.h"
+
+static char rcsid[] = "lburg.c - faked rcsid";
+
+static char *prefix = "";
+static int Tflag = 0;
+static int ntnumber = 0;
+static Nonterm start = 0;
+static Term terms;
+static Nonterm nts;
+static Rule rules;
+static int nrules;
+static struct block {
+	struct block *link;
+} *memlist;			/* list of allocated blocks */
+
+static char *stringf(char *fmt, ...);
+static void print(char *fmt, ...);
+static void ckreach(Nonterm p);
+static void emitclosure(Nonterm nts);
+static void emitcost(Tree t, char *v);
+static void emitdefs(Nonterm nts, int ntnumber);
+static void emitheader(void);
+static void emitkids(Rule rules, int nrules);
+static void emitnts(Rule rules, int nrules);
+static void emitrecalc(char *pre, Term root, Term kid);
+static void emitrecord(char *pre, Rule r, char *c, int cost);
+static void emitrule(Nonterm nts);
+static void emitlabel(Term terms, Nonterm start, int ntnumber);
+static void emitstring(Rule rules);
+static void emitstruct(Nonterm nts, int ntnumber);
+static void emittest(Tree t, char *v, char *suffix);
+
+int main(int argc, char *argv[]) {
+	int c, i;
+	Nonterm p;
+	
+	for (i = 1; i < argc; i++)
+		if (strcmp(argv[i], "-T") == 0)
+			Tflag = 1;
+		else if (strncmp(argv[i], "-p", 2) == 0 && argv[i][2])
+			prefix = &argv[i][2];
+		else if (strncmp(argv[i], "-p", 2) == 0 && i + 1 < argc)
+			prefix = argv[++i];
+		else if (*argv[i] == '-' && argv[i][1]) {
+			yyerror("usage: %s [-T | -p prefix]... [ [ input ] output ] \n",
+				argv[0]);
+			exit(1);
+		} else if (infp == NULL) {
+			if (strcmp(argv[i], "-") == 0)
+				infp = stdin;
+			else if ((infp = fopen(argv[i], "r")) == NULL) {
+				yyerror("%s: can't read `%s'\n", argv[0], argv[i]);
+				exit(1);
+			}
+		} else if (outfp == NULL) {
+			if (strcmp(argv[i], "-") == 0)
+				outfp = stdout;
+			if ((outfp = fopen(argv[i], "w")) == NULL) {
+				yyerror("%s: can't write `%s'\n", argv[0], argv[i]);
+				exit(1);
+			}
+		}
+	if (infp == NULL)
+		infp = stdin;
+	if (outfp == NULL)
+		outfp = stdout;
+	yyparse();
+	if (start)
+		ckreach(start);
+	for (p = nts; p; p = p->link) {
+		if (p->rules == NULL)
+			yyerror("undefined nonterminal `%s'\n", p->name);
+		if (!p->reached)
+			yyerror("can't reach nonterminal `%s'\n", p->name);
+	}
+	emitheader();
+	emitdefs(nts, ntnumber);
+	emitstruct(nts, ntnumber);
+	emitnts(rules, nrules);
+	emitstring(rules);
+	emitrule(nts);
+	emitclosure(nts);
+	if (start)
+		emitlabel(terms, start, ntnumber);
+	emitkids(rules, nrules);
+	if (!feof(infp))
+		while ((c = getc(infp)) != EOF)
+			putc(c, outfp);
+	while (memlist) {	/* for purify */
+		struct block *q = memlist->link;
+		free(memlist);
+		memlist = q;
+	}
+	return errcnt > 0;
+}
+
+/* alloc - allocate nbytes or issue fatal error */
+void *alloc(int nbytes) {
+	struct block *p = calloc(1, sizeof *p + nbytes);
+
+	if (p == NULL) {
+		yyerror("out of memory\n");
+		exit(1);
+	}
+	p->link = memlist;
+	memlist = p;
+	return p + 1;
+}
+
+/* stringf - format and save a string */
+static char *stringf(char *fmt, ...) {
+	va_list ap;
+	char buf[512];
+
+	va_start(ap, fmt);
+	vsprintf(buf, fmt, ap);
+	va_end(ap);
+	return strcpy(alloc(strlen(buf) + 1), buf);
+}	
+
+struct entry {
+	union {
+		char *name;
+		struct term t;
+		struct nonterm nt;
+	} sym;
+	struct entry *link;
+} *table[211];
+#define HASHSIZE (sizeof table/sizeof table[0])
+
+/* hash - return hash number for str */
+static unsigned hash(char *str) {
+	unsigned h = 0;
+
+	while (*str)
+		h = (h<<1) + *str++;
+	return h;
+}
+
+/* lookup - lookup symbol name */
+static void *lookup(char *name) {
+	struct entry *p = table[hash(name)%HASHSIZE];
+
+	for ( ; p; p = p->link)
+		if (strcmp(name, p->sym.name) == 0)
+			return &p->sym;
+	return 0;
+}
+
+/* install - install symbol name */
+static void *install(char *name) {
+	struct entry *p = alloc(sizeof *p);
+	int i = hash(name)%HASHSIZE;
+
+	p->sym.name = name;
+	p->link = table[i];
+	table[i] = p;
+	return &p->sym;
+}
+
+/* nonterm - create a new terminal id, if necessary */
+Nonterm nonterm(char *id) {
+	Nonterm p = lookup(id), *q = &nts;
+
+	if (p && p->kind == NONTERM)
+		return p;
+	if (p && p->kind == TERM)
+		yyerror("`%s' is a terminal\n", id);
+	p = install(id);
+	p->kind = NONTERM;
+	p->number = ++ntnumber;
+	if (p->number == 1)
+		start = p;
+	while (*q && (*q)->number < p->number)
+		q = &(*q)->link;
+	assert(*q == 0 || (*q)->number != p->number);
+	p->link = *q;
+	*q = p;
+	return p;
+}
+
+/* term - create a new terminal id with external symbol number esn */
+Term term(char *id, int esn) {
+	Term p = lookup(id), *q = &terms;
+
+	if (p)
+		yyerror("redefinition of terminal `%s'\n", id);
+	else
+		p = install(id);
+	p->kind = TERM;
+	p->esn = esn;
+	p->arity = -1;
+	while (*q && (*q)->esn < p->esn)
+		q = &(*q)->link;
+	if (*q && (*q)->esn == p->esn)
+		yyerror("duplicate external symbol number `%s=%d'\n",
+			p->name, p->esn);
+	p->link = *q;
+	*q = p;
+	return p;
+}
+
+/* tree - create & initialize a tree node with the given fields */
+Tree tree(char *id, Tree left, Tree right) {
+	Tree t = alloc(sizeof *t);
+	Term p = lookup(id);
+	int arity = 0;
+
+	if (left && right)
+		arity = 2;
+	else if (left)
+		arity = 1;
+	if (p == NULL && arity > 0) {
+		yyerror("undefined terminal `%s'\n", id);
+		p = term(id, -1);
+	} else if (p == NULL && arity == 0)
+		p = (Term)nonterm(id);
+	else if (p && p->kind == NONTERM && arity > 0) {
+		yyerror("`%s' is a nonterminal\n", id);
+		p = term(id, -1);
+	}
+	if (p->kind == TERM && p->arity == -1)
+		p->arity = arity;
+	if (p->kind == TERM && arity != p->arity)
+		yyerror("inconsistent arity for terminal `%s'\n", id);
+	t->op = p;
+	t->nterms = p->kind == TERM;
+	if ((t->left = left) != NULL)
+		t->nterms += left->nterms;
+	if ((t->right = right) != NULL)
+		t->nterms += right->nterms;
+	return t;
+}
+
+/* rule - create & initialize a rule with the given fields */
+Rule rule(char *id, Tree pattern, char *template, char *code) {
+	Rule r = alloc(sizeof *r), *q;
+	Term p = pattern->op;
+	char *end;
+
+	r->lhs = nonterm(id);
+	r->packed = ++r->lhs->lhscount;
+	for (q = &r->lhs->rules; *q; q = &(*q)->decode)
+		;
+	*q = r;
+	r->pattern = pattern;
+	r->ern = ++nrules;
+	r->template = template;
+	r->code = code;
+	r->cost = strtol(code, &end, 10);
+	if (*end) {
+		r->cost = -1;
+		r->code = stringf("(%s)", code);
+	}
+	if (p->kind == TERM) {
+		for (q = &p->rules; *q; q = &(*q)->next)
+			;
+		*q = r;
+	} else if (pattern->left == NULL && pattern->right == NULL) {
+		Nonterm p = pattern->op;
+		r->chain = p->chain;
+	        p->chain = r;
+		if (r->cost == -1)
+			yyerror("illegal nonconstant cost `%s'\n", code);
+	}
+	for (q = &rules; *q; q = &(*q)->link)
+		;
+	r->link = *q;
+	*q = r;
+	return r;
+}
+
+/* print - formatted output */
+static void print(char *fmt, ...) {
+	va_list ap;
+
+	va_start(ap, fmt);
+	for ( ; *fmt; fmt++)
+		if (*fmt == '%')
+			switch (*++fmt) {
+			case 'd': fprintf(outfp, "%d", va_arg(ap, int)); break;
+			case 's': fputs(va_arg(ap, char *), outfp); break;
+			case 'P': fprintf(outfp, "%s_", prefix); break;
+			case 'T': {
+				Tree t = va_arg(ap, Tree);
+				print("%S", t->op);
+				if (t->left && t->right)
+					print("(%T,%T)", t->left, t->right);
+				else if (t->left)
+					print("(%T)", t->left);
+				break;
+				}
+			case 'R': {
+				Rule r = va_arg(ap, Rule);
+				print("%S: %T", r->lhs, r->pattern);
+				break;
+				}
+			case 'S': fputs(va_arg(ap, Term)->name, outfp); break;
+			case '1': case '2': case '3': case '4': case '5': {
+				int n = *fmt - '0';
+				while (n-- > 0)
+					putc('\t', outfp);
+				break;
+				}
+			default: putc(*fmt, outfp); break;			
+			}
+		else
+			putc(*fmt, outfp);
+	va_end(ap);
+}
+
+/* reach - mark all nonterminals in tree t as reachable */
+static void reach(Tree t) {
+	Nonterm p = t->op;
+
+	if (p->kind == NONTERM)
+		if (!p->reached)
+			ckreach(p);
+	if (t->left)
+		reach(t->left);
+	if (t->right)
+		reach(t->right);
+}
+
+/* ckreach - mark all nonterminals reachable from p */
+static void ckreach(Nonterm p) {
+	Rule r;
+
+        p->reached = 1;
+	for (r = p->rules; r; r = r->decode)
+		reach(r->pattern);
+}
+
+/* emitcase - emit one case in function state */
+static void emitcase(Term p, int ntnumber) {
+	Rule r;
+
+	print("%1case %d: /* %S */\n", p->esn, p);
+	switch (p->arity) {
+	case 0: case -1:
+		break;
+	case 1:
+		print("%2%Plabel(LEFT_CHILD(a));\n");
+		break;
+	case 2:
+		print("%2%Plabel(LEFT_CHILD(a));\n");
+		print("%2%Plabel(RIGHT_CHILD(a));\n");
+		break;
+	default: assert(0);
+	}
+	for (r = p->rules; r; r = r->next) {
+		char *indent = "\t\t\0";
+		switch (p->arity) {
+		case 0: case -1:
+			print("%2/* %R */\n", r);
+			if (r->cost == -1) {
+				print("%2c = %s;\n", r->code);
+				emitrecord("\t\t", r, "c", 0);
+			} else
+				emitrecord("\t\t", r, r->code, 0);
+			break;
+		case 1:
+			if (r->pattern->nterms > 1) {
+				print("%2if (%1/* %R */\n", r);
+				emittest(r->pattern->left, "LEFT_CHILD(a)", " ");
+				print("%2) {\n");
+				indent = "\t\t\t";
+			} else
+				print("%2/* %R */\n", r);
+			if (r->pattern->nterms == 2 && r->pattern->left
+			&&  r->pattern->right == NULL)
+				emitrecalc(indent, r->pattern->op, r->pattern->left->op);
+			print("%sc = ", indent);
+			emitcost(r->pattern->left, "LEFT_CHILD(a)");
+			print("%s;\n", r->code);
+			emitrecord(indent, r, "c", 0);
+			if (indent[2])
+				print("%2}\n");
+			break;
+		case 2:
+			if (r->pattern->nterms > 1) {
+				print("%2if (%1/* %R */\n", r);
+				emittest(r->pattern->left,  "LEFT_CHILD(a)",
+					r->pattern->right->nterms ? " && " : " ");
+				emittest(r->pattern->right, "RIGHT_CHILD(a)", " ");
+				print("%2) {\n");
+				indent = "\t\t\t";
+			} else
+				print("%2/* %R */\n", r);
+			print("%sc = ", indent);
+			emitcost(r->pattern->left,  "LEFT_CHILD(a)");
+			emitcost(r->pattern->right, "RIGHT_CHILD(a)");
+			print("%s;\n", r->code);
+			emitrecord(indent, r, "c", 0);
+			if (indent[2])
+				print("%2}\n");
+			break;
+		default: assert(0);
+		}
+	}
+	print("%2break;\n");
+}
+
+/* emitclosure - emit the closure functions */
+static void emitclosure(Nonterm nts) {
+	Nonterm p;
+
+	for (p = nts; p; p = p->link)
+		if (p->chain)
+			print("static void %Pclosure_%S(NODEPTR_TYPE, int);\n", p);
+	print("\n");
+	for (p = nts; p; p = p->link)
+		if (p->chain) {
+			Rule r;
+			print("static void %Pclosure_%S(NODEPTR_TYPE a, int c) {\n"
+"%1struct %Pstate *p = STATE_LABEL(a);\n", p);
+			for (r = p->chain; r; r = r->chain)
+				emitrecord("\t", r, "c", r->cost);
+			print("}\n\n");
+		}
+}
+
+/* emitcost - emit cost computation for tree t */
+static void emitcost(Tree t, char *v) {
+	Nonterm p = t->op;
+
+	if (p->kind == TERM) {
+		if (t->left)
+			emitcost(t->left,  stringf("LEFT_CHILD(%s)",  v));
+		if (t->right)
+			emitcost(t->right, stringf("RIGHT_CHILD(%s)", v));
+	} else
+		print("((struct %Pstate *)(%s->x.state))->cost[%P%S_NT] + ", v, p);
+}
+
+/* emitdefs - emit nonterminal defines and data structures */
+static void emitdefs(Nonterm nts, int ntnumber) {
+	Nonterm p;
+
+	for (p = nts; p; p = p->link)
+		print("#define %P%S_NT %d\n", p, p->number);
+	print("\n");
+	print("static char *%Pntname[] = {\n%10,\n");
+	for (p = nts; p; p = p->link)
+		print("%1\"%S\",\n", p);
+	print("%10\n};\n\n");
+}
+
+/* emitheader - emit initial definitions */
+static void emitheader(void) {
+	time_t timer = time(NULL);
+
+	print("/*\ngenerated at %sby %s\n*/\n", ctime(&timer), rcsid);
+	print("static void %Pkids(NODEPTR_TYPE, int, NODEPTR_TYPE[]);\n");
+	print("static void %Plabel(NODEPTR_TYPE);\n");
+	print("static int %Prule(void*, int);\n\n");
+}
+
+/* computekids - compute paths to kids in tree t */
+static char *computekids(Tree t, char *v, char *bp, int *ip) {
+	Term p = t->op;
+
+	if (p->kind == NONTERM) {
+		sprintf(bp, "\t\tkids[%d] = %s;\n", (*ip)++, v);
+		bp += strlen(bp);
+	} else if (p->arity > 0) {
+		bp = computekids(t->left, stringf("LEFT_CHILD(%s)", v), bp, ip);
+		if (p->arity == 2)
+			bp = computekids(t->right, stringf("RIGHT_CHILD(%s)", v), bp, ip);
+	}
+	return bp;
+}
+
+/* emitkids - emit _kids */
+static void emitkids(Rule rules, int nrules) {
+	int i;
+	Rule r, *rc = alloc((nrules + 1 + 1)*sizeof *rc);
+	char **str  = alloc((nrules + 1 + 1)*sizeof *str);
+
+	for (i = 0, r = rules; r; r = r->link) {
+		int j = 0;
+		char buf[1024], *bp = buf;
+		*computekids(r->pattern, "p", bp, &j) = 0;
+		for (j = 0; str[j] && strcmp(str[j], buf); j++)
+			;
+		if (str[j] == NULL)
+			str[j] = strcpy(alloc(strlen(buf) + 1), buf);
+		r->kids = rc[j];
+		rc[j] = r;
+	}
+	print("static void %Pkids(NODEPTR_TYPE p, int eruleno, NODEPTR_TYPE kids[]) {\n"
+"%1if (!p)\n%2fatal(\"%Pkids\", \"Null tree\\n\", 0);\n"
+"%1if (!kids)\n%2fatal(\"%Pkids\", \"Null kids\\n\", 0);\n"
+"%1switch (eruleno) {\n");
+	for (i = 0; (r = rc[i]) != NULL; i++) {
+		for ( ; r; r = r->kids)
+			print("%1case %d: /* %R */\n", r->ern, r);
+		print("%s%2break;\n", str[i]);
+	}
+	print("%1default:\n%2fatal(\"%Pkids\", \"Bad rule number %%d\\n\", eruleno);\n%1}\n}\n\n");
+}
+
+/* emitlabel - emit label function */
+static void emitlabel(Term terms, Nonterm start, int ntnumber) {
+	int i;
+	Term p;
+
+	print("static void %Plabel(NODEPTR_TYPE a) {\n%1int c;\n"
+"%1struct %Pstate *p;\n\n"
+"%1if (!a)\n%2fatal(\"%Plabel\", \"Null tree\\n\", 0);\n");
+	print("%1STATE_LABEL(a) = p = allocate(sizeof *p, FUNC);\n"
+"%1p->rule._stmt = 0;\n");
+	for (i = 1; i <= ntnumber; i++)
+		print("%1p->cost[%d] =\n", i);
+	print("%20x7fff;\n%1switch (OP_LABEL(a)) {\n");
+	for (p = terms; p; p = p->link)
+		emitcase(p, ntnumber);
+	print("%1default:\n"
+"%2fatal(\"%Plabel\", \"Bad terminal %%d\\n\", OP_LABEL(a));\n%1}\n}\n\n");
+}
+
+/* computents - fill in bp with _nts vector for tree t */
+static char *computents(Tree t, char *bp) {
+	if (t) {
+		Nonterm p = t->op;
+		if (p->kind == NONTERM) {
+			sprintf(bp, "%s_%s_NT, ", prefix, p->name);
+			bp += strlen(bp);
+		} else
+			bp = computents(t->right, computents(t->left,  bp));
+	}
+	return bp;
+}
+
+/* emitnts - emit _nts ragged array */
+static void emitnts(Rule rules, int nrules) {
+	Rule r;
+	int i, j, *nts = alloc((nrules + 1)*sizeof *nts);
+	char **str = alloc((nrules + 1)*sizeof *str);
+
+	for (i = 0, r = rules; r; r = r->link) {
+		char buf[1024];
+		*computents(r->pattern, buf) = 0;
+		for (j = 0; str[j] && strcmp(str[j], buf); j++)
+			;
+		if (str[j] == NULL) {
+			print("static short %Pnts_%d[] = { %s0 };\n", j, buf);
+			str[j] = strcpy(alloc(strlen(buf) + 1), buf);
+		}
+		nts[i++] = j;
+	}
+	print("\nstatic short *%Pnts[] = {\n");
+	for (i = j = 0, r = rules; r; r = r->link) {
+		for ( ; j < r->ern; j++)
+			print("%10,%1/* %d */\n", j);
+		print("%1%Pnts_%d,%1/* %d */\n", nts[i++], j++);
+	}
+	print("};\n\n");
+}
+
+/* emitrecalc - emit code that tests for recalculation of INDIR?(VREGP) */
+static void emitrecalc(char *pre, Term root, Term kid) {
+	if (root->kind == TERM && strncmp(root->name, "INDIR", 5) == 0
+	&&   kid->kind == TERM &&  strcmp(kid->name,  "VREGP"   ) == 0) {
+		Nonterm p;
+		print("%sif (mayrecalc(a)) {\n", pre);
+		print("%s%1struct %Pstate *q = a->syms[RX]->u.t.cse->x.state;\n", pre);
+		for (p = nts; p; p = p->link) {
+			print("%s%1if (q->cost[%P%S_NT] == 0) {\n", pre, p);
+			print("%s%2p->cost[%P%S_NT] = 0;\n", pre, p);
+			print("%s%2p->rule.%P%S = q->rule.%P%S;\n", pre, p, p);
+			print("%s%1}\n", pre);
+		}
+		print("%s}\n", pre);
+	}
+}
+
+/* emitrecord - emit code that tests for a winning match of rule r */
+static void emitrecord(char *pre, Rule r, char *c, int cost) {
+	if (Tflag)
+		print("%s%Ptrace(a, %d, %s + %d, p->cost[%P%S_NT]);\n",
+			pre, r->ern, c, cost, r->lhs);
+	print("%sif (", pre);
+	print("%s + %d < p->cost[%P%S_NT]) {\n"
+"%s%1p->cost[%P%S_NT] = %s + %d;\n%s%1p->rule.%P%S = %d;\n",
+		c, cost, r->lhs, pre, r->lhs, c, cost, pre, r->lhs,
+		r->packed);
+	if (r->lhs->chain)
+		print("%s%1%Pclosure_%S(a, %s + %d);\n", pre, r->lhs, c, cost);
+	print("%s}\n", pre);
+}
+
+/* emitrule - emit decoding vectors and _rule */
+static void emitrule(Nonterm nts) {
+	Nonterm p;
+
+	for (p = nts; p; p = p->link) {
+		Rule r;
+		print("static short %Pdecode_%S[] = {\n%10,\n", p);
+		for (r = p->rules; r; r = r->decode)
+			print("%1%d,\n", r->ern);
+		print("};\n\n");
+	}
+	print("static int %Prule(void *state, int goalnt) {\n"
+"%1if (goalnt < 1 || goalnt > %d)\n%2fatal(\"%Prule\", \"Bad goal nonterminal %%d\\n\", goalnt);\n"
+"%1if (!state)\n%2return 0;\n%1switch (goalnt) {\n", ntnumber);
+	for (p = nts; p; p = p->link)
+		print("%1case %P%S_NT:"
+"%1return %Pdecode_%S[((struct %Pstate *)state)->rule.%P%S];\n", p, p, p);
+	print("%1default:\n%2fatal(\"%Prule\", \"Bad goal nonterminal %%d\\n\", goalnt);\n%2return 0;\n%1}\n}\n\n");
+}
+
+/* emitstring - emit arrays of templates, instruction flags, and rules */
+static void emitstring(Rule rules) {
+	Rule r;
+
+	print("static char *%Ptemplates[] = {\n");
+	print("/* 0 */%10,\n");
+	for (r = rules; r; r = r->link)
+		print("/* %d */%1\"%s\",%1/* %R */\n", r->ern, r->template, r);
+	print("};\n");
+	print("\nstatic char %Pisinstruction[] = {\n");
+	print("/* 0 */%10,\n");
+	for (r = rules; r; r = r->link) {
+		int len = strlen(r->template);
+		print("/* %d */%1%d,%1/* %s */\n", r->ern,
+			len >= 2 && r->template[len-2] == '\\' && r->template[len-1] == 'n',
+			r->template);
+	}
+	print("};\n");
+	print("\nstatic char *%Pstring[] = {\n");
+	print("/* 0 */%10,\n");
+	for (r = rules; r; r = r->link)
+		print("/* %d */%1\"%R\",\n", r->ern, r);
+	print("};\n\n");
+}
+
+/* emitstruct - emit the definition of the state structure */
+static void emitstruct(Nonterm nts, int ntnumber) {
+	print("struct %Pstate {\n%1short cost[%d];\n%1struct {\n", ntnumber + 1);
+	for ( ; nts; nts = nts->link) {
+		int n = 1, m = nts->lhscount;
+		while ((m >>= 1) != 0)
+			n++;		
+		print("%2unsigned int %P%S:%d;\n", nts, n);
+	}
+	print("%1} rule;\n};\n\n");
+}
+
+/* emittest - emit clause for testing a match */
+static void emittest(Tree t, char *v, char *suffix) {
+	Term p = t->op;
+
+	if (p->kind == TERM) {
+		print("%3%s->op == %d%s/* %S */\n", v, p->esn,
+			t->nterms > 1 ? " && " : suffix, p);
+		if (t->left)
+			emittest(t->left, stringf("LEFT_CHILD(%s)",  v),
+				t->right && t->right->nterms ? " && " : suffix);
+		if (t->right)
+			emittest(t->right, stringf("RIGHT_CHILD(%s)", v), suffix);
+	}
+}