--- /dev/null
+/*
+ * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
+ * Released under the terms of the GNU GPL v2.0.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define LKC_DIRECT_LINK
+#include "lkc.h"
+
+#define DEBUG_EXPR 0
+
+struct expr *expr_alloc_symbol(struct symbol *sym)
+{
+ struct expr *e = malloc(sizeof(*e));
+ memset(e, 0, sizeof(*e));
+ e->type = E_SYMBOL;
+ e->left.sym = sym;
+ return e;
+}
+
+struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
+{
+ struct expr *e = malloc(sizeof(*e));
+ memset(e, 0, sizeof(*e));
+ e->type = type;
+ e->left.expr = ce;
+ return e;
+}
+
+struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
+{
+ struct expr *e = malloc(sizeof(*e));
+ memset(e, 0, sizeof(*e));
+ e->type = type;
+ e->left.expr = e1;
+ e->right.expr = e2;
+ return e;
+}
+
+struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
+{
+ struct expr *e = malloc(sizeof(*e));
+ memset(e, 0, sizeof(*e));
+ e->type = type;
+ e->left.sym = s1;
+ e->right.sym = s2;
+ return e;
+}
+
+struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
+{
+ if (!e1)
+ return e2;
+ return e2 ? expr_alloc_two(E_AND, e1, e2) : e1;
+}
+
+struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
+{
+ if (!e1)
+ return e2;
+ return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
+}
+
+struct expr *expr_copy(struct expr *org)
+{
+ struct expr *e;
+
+ if (!org)
+ return NULL;
+
+ e = malloc(sizeof(*org));
+ memcpy(e, org, sizeof(*org));
+ switch (org->type) {
+ case E_SYMBOL:
+ e->left = org->left;
+ break;
+ case E_NOT:
+ e->left.expr = expr_copy(org->left.expr);
+ break;
+ case E_EQUAL:
+ case E_UNEQUAL:
+ e->left.sym = org->left.sym;
+ e->right.sym = org->right.sym;
+ break;
+ case E_AND:
+ case E_OR:
+ case E_CHOICE:
+ e->left.expr = expr_copy(org->left.expr);
+ e->right.expr = expr_copy(org->right.expr);
+ break;
+ default:
+ printf("can't copy type %d\n", e->type);
+ free(e);
+ e = NULL;
+ break;
+ }
+
+ return e;
+}
+
+void expr_free(struct expr *e)
+{
+ if (!e)
+ return;
+
+ switch (e->type) {
+ case E_SYMBOL:
+ break;
+ case E_NOT:
+ expr_free(e->left.expr);
+ return;
+ case E_EQUAL:
+ case E_UNEQUAL:
+ break;
+ case E_OR:
+ case E_AND:
+ expr_free(e->left.expr);
+ expr_free(e->right.expr);
+ break;
+ default:
+ printf("how to free type %d?\n", e->type);
+ break;
+ }
+ free(e);
+}
+
+static int trans_count;
+
+#define e1 (*ep1)
+#define e2 (*ep2)
+
+static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
+{
+ if (e1->type == type) {
+ __expr_eliminate_eq(type, &e1->left.expr, &e2);
+ __expr_eliminate_eq(type, &e1->right.expr, &e2);
+ return;
+ }
+ if (e2->type == type) {
+ __expr_eliminate_eq(type, &e1, &e2->left.expr);
+ __expr_eliminate_eq(type, &e1, &e2->right.expr);
+ return;
+ }
+ if (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
+ e1->left.sym == e2->left.sym && (e1->left.sym->flags & (SYMBOL_YES|SYMBOL_NO)))
+ return;
+ if (!expr_eq(e1, e2))
+ return;
+ trans_count++;
+ expr_free(e1); expr_free(e2);
+ switch (type) {
+ case E_OR:
+ e1 = expr_alloc_symbol(&symbol_no);
+ e2 = expr_alloc_symbol(&symbol_no);
+ break;
+ case E_AND:
+ e1 = expr_alloc_symbol(&symbol_yes);
+ e2 = expr_alloc_symbol(&symbol_yes);
+ break;
+ default:
+ ;
+ }
+}
+
+void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
+{
+ if (!e1 || !e2)
+ return;
+ switch (e1->type) {
+ case E_OR:
+ case E_AND:
+ __expr_eliminate_eq(e1->type, ep1, ep2);
+ default:
+ ;
+ }
+ if (e1->type != e2->type) switch (e2->type) {
+ case E_OR:
+ case E_AND:
+ __expr_eliminate_eq(e2->type, ep1, ep2);
+ default:
+ ;
+ }
+ e1 = expr_eliminate_yn(e1);
+ e2 = expr_eliminate_yn(e2);
+}
+
+#undef e1
+#undef e2
+
+int expr_eq(struct expr *e1, struct expr *e2)
+{
+ int res, old_count;
+
+ if (e1->type != e2->type)
+ return 0;
+ switch (e1->type) {
+ case E_EQUAL:
+ case E_UNEQUAL:
+ return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
+ case E_SYMBOL:
+ return e1->left.sym == e2->left.sym;
+ case E_NOT:
+ return expr_eq(e1->left.expr, e2->left.expr);
+ case E_AND:
+ case E_OR:
+ e1 = expr_copy(e1);
+ e2 = expr_copy(e2);
+ old_count = trans_count;
+ expr_eliminate_eq(&e1, &e2);
+ res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
+ e1->left.sym == e2->left.sym);
+ expr_free(e1);
+ expr_free(e2);
+ trans_count = old_count;
+ return res;
+ case E_CHOICE:
+ case E_RANGE:
+ case E_NONE:
+ /* panic */;
+ }
+
+ if (DEBUG_EXPR) {
+ expr_fprint(e1, stdout);
+ printf(" = ");
+ expr_fprint(e2, stdout);
+ printf(" ?\n");
+ }
+
+ return 0;
+}
+
+struct expr *expr_eliminate_yn(struct expr *e)
+{
+ struct expr *tmp;
+
+ if (e) switch (e->type) {
+ case E_AND:
+ e->left.expr = expr_eliminate_yn(e->left.expr);
+ e->right.expr = expr_eliminate_yn(e->right.expr);
+ if (e->left.expr->type == E_SYMBOL) {
+ if (e->left.expr->left.sym == &symbol_no) {
+ expr_free(e->left.expr);
+ expr_free(e->right.expr);
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_no;
+ e->right.expr = NULL;
+ return e;
+ } else if (e->left.expr->left.sym == &symbol_yes) {
+ free(e->left.expr);
+ tmp = e->right.expr;
+ *e = *(e->right.expr);
+ free(tmp);
+ return e;
+ }
+ }
+ if (e->right.expr->type == E_SYMBOL) {
+ if (e->right.expr->left.sym == &symbol_no) {
+ expr_free(e->left.expr);
+ expr_free(e->right.expr);
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_no;
+ e->right.expr = NULL;
+ return e;
+ } else if (e->right.expr->left.sym == &symbol_yes) {
+ free(e->right.expr);
+ tmp = e->left.expr;
+ *e = *(e->left.expr);
+ free(tmp);
+ return e;
+ }
+ }
+ break;
+ case E_OR:
+ e->left.expr = expr_eliminate_yn(e->left.expr);
+ e->right.expr = expr_eliminate_yn(e->right.expr);
+ if (e->left.expr->type == E_SYMBOL) {
+ if (e->left.expr->left.sym == &symbol_no) {
+ free(e->left.expr);
+ tmp = e->right.expr;
+ *e = *(e->right.expr);
+ free(tmp);
+ return e;
+ } else if (e->left.expr->left.sym == &symbol_yes) {
+ expr_free(e->left.expr);
+ expr_free(e->right.expr);
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_yes;
+ e->right.expr = NULL;
+ return e;
+ }
+ }
+ if (e->right.expr->type == E_SYMBOL) {
+ if (e->right.expr->left.sym == &symbol_no) {
+ free(e->right.expr);
+ tmp = e->left.expr;
+ *e = *(e->left.expr);
+ free(tmp);
+ return e;
+ } else if (e->right.expr->left.sym == &symbol_yes) {
+ expr_free(e->left.expr);
+ expr_free(e->right.expr);
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_yes;
+ e->right.expr = NULL;
+ return e;
+ }
+ }
+ break;
+ default:
+ ;
+ }
+ return e;
+}
+
+/*
+ * bool FOO!=n => FOO
+ */
+struct expr *expr_trans_bool(struct expr *e)
+{
+ if (!e)
+ return NULL;
+ switch (e->type) {
+ case E_AND:
+ case E_OR:
+ case E_NOT:
+ e->left.expr = expr_trans_bool(e->left.expr);
+ e->right.expr = expr_trans_bool(e->right.expr);
+ break;
+ case E_UNEQUAL:
+ // FOO!=n -> FOO
+ if (e->left.sym->type == S_TRISTATE) {
+ if (e->right.sym == &symbol_no) {
+ e->type = E_SYMBOL;
+ e->right.sym = NULL;
+ }
+ }
+ break;
+ default:
+ ;
+ }
+ return e;
+}
+
+/*
+ * e1 || e2 -> ?
+ */
+struct expr *expr_join_or(struct expr *e1, struct expr *e2)
+{
+ struct expr *tmp;
+ struct symbol *sym1, *sym2;
+
+ if (expr_eq(e1, e2))
+ return expr_copy(e1);
+ if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
+ return NULL;
+ if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
+ return NULL;
+ if (e1->type == E_NOT) {
+ tmp = e1->left.expr;
+ if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
+ return NULL;
+ sym1 = tmp->left.sym;
+ } else
+ sym1 = e1->left.sym;
+ if (e2->type == E_NOT) {
+ if (e2->left.expr->type != E_SYMBOL)
+ return NULL;
+ sym2 = e2->left.expr->left.sym;
+ } else
+ sym2 = e2->left.sym;
+ if (sym1 != sym2)
+ return NULL;
+ if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
+ return NULL;
+ if (sym1->type == S_TRISTATE) {
+ if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
+ ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
+ (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
+ // (a='y') || (a='m') -> (a!='n')
+ return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
+ }
+ if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
+ ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
+ (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
+ // (a='y') || (a='n') -> (a!='m')
+ return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
+ }
+ if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
+ ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
+ (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
+ // (a='m') || (a='n') -> (a!='y')
+ return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
+ }
+ }
+ if (sym1->type == S_BOOLEAN && sym1 == sym2) {
+ if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
+ (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
+ return expr_alloc_symbol(&symbol_yes);
+ }
+
+ if (DEBUG_EXPR) {
+ printf("optimize (");
+ expr_fprint(e1, stdout);
+ printf(") || (");
+ expr_fprint(e2, stdout);
+ printf(")?\n");
+ }
+ return NULL;
+}
+
+struct expr *expr_join_and(struct expr *e1, struct expr *e2)
+{
+ struct expr *tmp;
+ struct symbol *sym1, *sym2;
+
+ if (expr_eq(e1, e2))
+ return expr_copy(e1);
+ if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
+ return NULL;
+ if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
+ return NULL;
+ if (e1->type == E_NOT) {
+ tmp = e1->left.expr;
+ if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
+ return NULL;
+ sym1 = tmp->left.sym;
+ } else
+ sym1 = e1->left.sym;
+ if (e2->type == E_NOT) {
+ if (e2->left.expr->type != E_SYMBOL)
+ return NULL;
+ sym2 = e2->left.expr->left.sym;
+ } else
+ sym2 = e2->left.sym;
+ if (sym1 != sym2)
+ return NULL;
+ if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
+ return NULL;
+
+ if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
+ (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
+ // (a) && (a='y') -> (a='y')
+ return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
+
+ if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
+ (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
+ // (a) && (a!='n') -> (a)
+ return expr_alloc_symbol(sym1);
+
+ if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
+ (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
+ // (a) && (a!='m') -> (a='y')
+ return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
+
+ if (sym1->type == S_TRISTATE) {
+ if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
+ // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
+ sym2 = e1->right.sym;
+ if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
+ return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
+ : expr_alloc_symbol(&symbol_no);
+ }
+ if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
+ // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
+ sym2 = e2->right.sym;
+ if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
+ return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
+ : expr_alloc_symbol(&symbol_no);
+ }
+ if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
+ ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
+ (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
+ // (a!='y') && (a!='n') -> (a='m')
+ return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
+
+ if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
+ ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
+ (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
+ // (a!='y') && (a!='m') -> (a='n')
+ return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
+
+ if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
+ ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
+ (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
+ // (a!='m') && (a!='n') -> (a='m')
+ return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
+
+ if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
+ (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
+ (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
+ (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
+ return NULL;
+ }
+
+ if (DEBUG_EXPR) {
+ printf("optimize (");
+ expr_fprint(e1, stdout);
+ printf(") && (");
+ expr_fprint(e2, stdout);
+ printf(")?\n");
+ }
+ return NULL;
+}
+
+static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
+{
+#define e1 (*ep1)
+#define e2 (*ep2)
+ struct expr *tmp;
+
+ if (e1->type == type) {
+ expr_eliminate_dups1(type, &e1->left.expr, &e2);
+ expr_eliminate_dups1(type, &e1->right.expr, &e2);
+ return;
+ }
+ if (e2->type == type) {
+ expr_eliminate_dups1(type, &e1, &e2->left.expr);
+ expr_eliminate_dups1(type, &e1, &e2->right.expr);
+ return;
+ }
+ if (e1 == e2)
+ return;
+
+ switch (e1->type) {
+ case E_OR: case E_AND:
+ expr_eliminate_dups1(e1->type, &e1, &e1);
+ default:
+ ;
+ }
+
+ switch (type) {
+ case E_OR:
+ tmp = expr_join_or(e1, e2);
+ if (tmp) {
+ expr_free(e1); expr_free(e2);
+ e1 = expr_alloc_symbol(&symbol_no);
+ e2 = tmp;
+ trans_count++;
+ }
+ break;
+ case E_AND:
+ tmp = expr_join_and(e1, e2);
+ if (tmp) {
+ expr_free(e1); expr_free(e2);
+ e1 = expr_alloc_symbol(&symbol_yes);
+ e2 = tmp;
+ trans_count++;
+ }
+ break;
+ default:
+ ;
+ }
+#undef e1
+#undef e2
+}
+
+static void expr_eliminate_dups2(enum expr_type type, struct expr **ep1, struct expr **ep2)
+{
+#define e1 (*ep1)
+#define e2 (*ep2)
+ struct expr *tmp, *tmp1, *tmp2;
+
+ if (e1->type == type) {
+ expr_eliminate_dups2(type, &e1->left.expr, &e2);
+ expr_eliminate_dups2(type, &e1->right.expr, &e2);
+ return;
+ }
+ if (e2->type == type) {
+ expr_eliminate_dups2(type, &e1, &e2->left.expr);
+ expr_eliminate_dups2(type, &e1, &e2->right.expr);
+ }
+ if (e1 == e2)
+ return;
+
+ switch (e1->type) {
+ case E_OR:
+ expr_eliminate_dups2(e1->type, &e1, &e1);
+ // (FOO || BAR) && (!FOO && !BAR) -> n
+ tmp1 = expr_transform(expr_alloc_one(E_NOT, expr_copy(e1)));
+ tmp2 = expr_copy(e2);
+ tmp = expr_extract_eq_and(&tmp1, &tmp2);
+ if (expr_is_yes(tmp1)) {
+ expr_free(e1);
+ e1 = expr_alloc_symbol(&symbol_no);
+ trans_count++;
+ }
+ expr_free(tmp2);
+ expr_free(tmp1);
+ expr_free(tmp);
+ break;
+ case E_AND:
+ expr_eliminate_dups2(e1->type, &e1, &e1);
+ // (FOO && BAR) || (!FOO || !BAR) -> y
+ tmp1 = expr_transform(expr_alloc_one(E_NOT, expr_copy(e1)));
+ tmp2 = expr_copy(e2);
+ tmp = expr_extract_eq_or(&tmp1, &tmp2);
+ if (expr_is_no(tmp1)) {
+ expr_free(e1);
+ e1 = expr_alloc_symbol(&symbol_yes);
+ trans_count++;
+ }
+ expr_free(tmp2);
+ expr_free(tmp1);
+ expr_free(tmp);
+ break;
+ default:
+ ;
+ }
+#undef e1
+#undef e2
+}
+
+struct expr *expr_eliminate_dups(struct expr *e)
+{
+ int oldcount;
+ if (!e)
+ return e;
+
+ oldcount = trans_count;
+ while (1) {
+ trans_count = 0;
+ switch (e->type) {
+ case E_OR: case E_AND:
+ expr_eliminate_dups1(e->type, &e, &e);
+ expr_eliminate_dups2(e->type, &e, &e);
+ default:
+ ;
+ }
+ if (!trans_count)
+ break;
+ e = expr_eliminate_yn(e);
+ }
+ trans_count = oldcount;
+ return e;
+}
+
+struct expr *expr_transform(struct expr *e)
+{
+ struct expr *tmp;
+
+ if (!e)
+ return NULL;
+ switch (e->type) {
+ case E_EQUAL:
+ case E_UNEQUAL:
+ case E_SYMBOL:
+ case E_CHOICE:
+ break;
+ default:
+ e->left.expr = expr_transform(e->left.expr);
+ e->right.expr = expr_transform(e->right.expr);
+ }
+
+ switch (e->type) {
+ case E_EQUAL:
+ if (e->left.sym->type != S_BOOLEAN)
+ break;
+ if (e->right.sym == &symbol_no) {
+ e->type = E_NOT;
+ e->left.expr = expr_alloc_symbol(e->left.sym);
+ e->right.sym = NULL;
+ break;
+ }
+ if (e->right.sym == &symbol_mod) {
+ printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_no;
+ e->right.sym = NULL;
+ break;
+ }
+ if (e->right.sym == &symbol_yes) {
+ e->type = E_SYMBOL;
+ e->right.sym = NULL;
+ break;
+ }
+ break;
+ case E_UNEQUAL:
+ if (e->left.sym->type != S_BOOLEAN)
+ break;
+ if (e->right.sym == &symbol_no) {
+ e->type = E_SYMBOL;
+ e->right.sym = NULL;
+ break;
+ }
+ if (e->right.sym == &symbol_mod) {
+ printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_yes;
+ e->right.sym = NULL;
+ break;
+ }
+ if (e->right.sym == &symbol_yes) {
+ e->type = E_NOT;
+ e->left.expr = expr_alloc_symbol(e->left.sym);
+ e->right.sym = NULL;
+ break;
+ }
+ break;
+ case E_NOT:
+ switch (e->left.expr->type) {
+ case E_NOT:
+ // !!a -> a
+ tmp = e->left.expr->left.expr;
+ free(e->left.expr);
+ free(e);
+ e = tmp;
+ e = expr_transform(e);
+ break;
+ case E_EQUAL:
+ case E_UNEQUAL:
+ // !a='x' -> a!='x'
+ tmp = e->left.expr;
+ free(e);
+ e = tmp;
+ e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
+ break;
+ case E_OR:
+ // !(a || b) -> !a && !b
+ tmp = e->left.expr;
+ e->type = E_AND;
+ e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
+ tmp->type = E_NOT;
+ tmp->right.expr = NULL;
+ e = expr_transform(e);
+ break;
+ case E_AND:
+ // !(a && b) -> !a || !b
+ tmp = e->left.expr;
+ e->type = E_OR;
+ e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
+ tmp->type = E_NOT;
+ tmp->right.expr = NULL;
+ e = expr_transform(e);
+ break;
+ case E_SYMBOL:
+ if (e->left.expr->left.sym == &symbol_yes) {
+ // !'y' -> 'n'
+ tmp = e->left.expr;
+ free(e);
+ e = tmp;
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_no;
+ break;
+ }
+ if (e->left.expr->left.sym == &symbol_mod) {
+ // !'m' -> 'm'
+ tmp = e->left.expr;
+ free(e);
+ e = tmp;
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_mod;
+ break;
+ }
+ if (e->left.expr->left.sym == &symbol_no) {
+ // !'n' -> 'y'
+ tmp = e->left.expr;
+ free(e);
+ e = tmp;
+ e->type = E_SYMBOL;
+ e->left.sym = &symbol_yes;
+ break;
+ }
+ break;
+ default:
+ ;
+ }
+ break;
+ default:
+ ;
+ }
+ return e;
+}
+
+int expr_contains_symbol(struct expr *dep, struct symbol *sym)
+{
+ if (!dep)
+ return 0;
+
+ switch (dep->type) {
+ case E_AND:
+ case E_OR:
+ return expr_contains_symbol(dep->left.expr, sym) ||
+ expr_contains_symbol(dep->right.expr, sym);
+ case E_SYMBOL:
+ return dep->left.sym == sym;
+ case E_EQUAL:
+ case E_UNEQUAL:
+ return dep->left.sym == sym ||
+ dep->right.sym == sym;
+ case E_NOT:
+ return expr_contains_symbol(dep->left.expr, sym);
+ default:
+ ;
+ }
+ return 0;
+}
+
+bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
+{
+ if (!dep)
+ return false;
+
+ switch (dep->type) {
+ case E_AND:
+ return expr_depends_symbol(dep->left.expr, sym) ||
+ expr_depends_symbol(dep->right.expr, sym);
+ case E_SYMBOL:
+ return dep->left.sym == sym;
+ case E_EQUAL:
+ if (dep->left.sym == sym) {
+ if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
+ return true;
+ }
+ break;
+ case E_UNEQUAL:
+ if (dep->left.sym == sym) {
+ if (dep->right.sym == &symbol_no)
+ return true;
+ }
+ break;
+ default:
+ ;
+ }
+ return false;
+}
+
+struct expr *expr_extract_eq_and(struct expr **ep1, struct expr **ep2)
+{
+ struct expr *tmp = NULL;
+ expr_extract_eq(E_AND, &tmp, ep1, ep2);
+ if (tmp) {
+ *ep1 = expr_eliminate_yn(*ep1);
+ *ep2 = expr_eliminate_yn(*ep2);
+ }
+ return tmp;
+}
+
+struct expr *expr_extract_eq_or(struct expr **ep1, struct expr **ep2)
+{
+ struct expr *tmp = NULL;
+ expr_extract_eq(E_OR, &tmp, ep1, ep2);
+ if (tmp) {
+ *ep1 = expr_eliminate_yn(*ep1);
+ *ep2 = expr_eliminate_yn(*ep2);
+ }
+ return tmp;
+}
+
+void expr_extract_eq(enum expr_type type, struct expr **ep, struct expr **ep1, struct expr **ep2)
+{
+#define e1 (*ep1)
+#define e2 (*ep2)
+ if (e1->type == type) {
+ expr_extract_eq(type, ep, &e1->left.expr, &e2);
+ expr_extract_eq(type, ep, &e1->right.expr, &e2);
+ return;
+ }
+ if (e2->type == type) {
+ expr_extract_eq(type, ep, ep1, &e2->left.expr);
+ expr_extract_eq(type, ep, ep1, &e2->right.expr);
+ return;
+ }
+ if (expr_eq(e1, e2)) {
+ *ep = *ep ? expr_alloc_two(type, *ep, e1) : e1;
+ expr_free(e2);
+ if (type == E_AND) {
+ e1 = expr_alloc_symbol(&symbol_yes);
+ e2 = expr_alloc_symbol(&symbol_yes);
+ } else if (type == E_OR) {
+ e1 = expr_alloc_symbol(&symbol_no);
+ e2 = expr_alloc_symbol(&symbol_no);
+ }
+ }
+#undef e1
+#undef e2
+}
+
+struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
+{
+ struct expr *e1, *e2;
+
+ if (!e) {
+ e = expr_alloc_symbol(sym);
+ if (type == E_UNEQUAL)
+ e = expr_alloc_one(E_NOT, e);
+ return e;
+ }
+ switch (e->type) {
+ case E_AND:
+ e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
+ e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
+ if (sym == &symbol_yes)
+ e = expr_alloc_two(E_AND, e1, e2);
+ if (sym == &symbol_no)
+ e = expr_alloc_two(E_OR, e1, e2);
+ if (type == E_UNEQUAL)
+ e = expr_alloc_one(E_NOT, e);
+ return e;
+ case E_OR:
+ e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
+ e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
+ if (sym == &symbol_yes)
+ e = expr_alloc_two(E_OR, e1, e2);
+ if (sym == &symbol_no)
+ e = expr_alloc_two(E_AND, e1, e2);
+ if (type == E_UNEQUAL)
+ e = expr_alloc_one(E_NOT, e);
+ return e;
+ case E_NOT:
+ return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
+ case E_UNEQUAL:
+ case E_EQUAL:
+ if (type == E_EQUAL) {
+ if (sym == &symbol_yes)
+ return expr_copy(e);
+ if (sym == &symbol_mod)
+ return expr_alloc_symbol(&symbol_no);
+ if (sym == &symbol_no)
+ return expr_alloc_one(E_NOT, expr_copy(e));
+ } else {
+ if (sym == &symbol_yes)
+ return expr_alloc_one(E_NOT, expr_copy(e));
+ if (sym == &symbol_mod)
+ return expr_alloc_symbol(&symbol_yes);
+ if (sym == &symbol_no)
+ return expr_copy(e);
+ }
+ break;
+ case E_SYMBOL:
+ return expr_alloc_comp(type, e->left.sym, sym);
+ case E_CHOICE:
+ case E_RANGE:
+ case E_NONE:
+ /* panic */;
+ }
+ return NULL;
+}
+
+tristate expr_calc_value(struct expr *e)
+{
+ tristate val1, val2;
+ const char *str1, *str2;
+
+ if (!e)
+ return yes;
+
+ switch (e->type) {
+ case E_SYMBOL:
+ sym_calc_value(e->left.sym);
+ return e->left.sym->curr.tri;
+ case E_AND:
+ val1 = expr_calc_value(e->left.expr);
+ val2 = expr_calc_value(e->right.expr);
+ return E_AND(val1, val2);
+ case E_OR:
+ val1 = expr_calc_value(e->left.expr);
+ val2 = expr_calc_value(e->right.expr);
+ return E_OR(val1, val2);
+ case E_NOT:
+ val1 = expr_calc_value(e->left.expr);
+ return E_NOT(val1);
+ case E_EQUAL:
+ sym_calc_value(e->left.sym);
+ sym_calc_value(e->right.sym);
+ str1 = sym_get_string_value(e->left.sym);
+ str2 = sym_get_string_value(e->right.sym);
+ return !strcmp(str1, str2) ? yes : no;
+ case E_UNEQUAL:
+ sym_calc_value(e->left.sym);
+ sym_calc_value(e->right.sym);
+ str1 = sym_get_string_value(e->left.sym);
+ str2 = sym_get_string_value(e->right.sym);
+ return !strcmp(str1, str2) ? no : yes;
+ default:
+ printf("expr_calc_value: %d?\n", e->type);
+ return no;
+ }
+}
+
+int expr_compare_type(enum expr_type t1, enum expr_type t2)
+{
+#if 0
+ return 1;
+#else
+ if (t1 == t2)
+ return 0;
+ switch (t1) {
+ case E_EQUAL:
+ case E_UNEQUAL:
+ if (t2 == E_NOT)
+ return 1;
+ case E_NOT:
+ if (t2 == E_AND)
+ return 1;
+ case E_AND:
+ if (t2 == E_OR)
+ return 1;
+ case E_OR:
+ if (t2 == E_CHOICE)
+ return 1;
+ case E_CHOICE:
+ if (t2 == 0)
+ return 1;
+ default:
+ return -1;
+ }
+ printf("[%dgt%d?]", t1, t2);
+ return 0;
+#endif
+}
+
+void expr_print(struct expr *e, void (*fn)(void *, const char *), void *data, int prevtoken)
+{
+ if (!e) {
+ fn(data, "y");
+ return;
+ }
+
+ if (expr_compare_type(prevtoken, e->type) > 0)
+ fn(data, "(");
+ switch (e->type) {
+ case E_SYMBOL:
+ if (e->left.sym->name)
+ fn(data, e->left.sym->name);
+ else
+ fn(data, "<choice>");
+ break;
+ case E_NOT:
+ fn(data, "!");
+ expr_print(e->left.expr, fn, data, E_NOT);
+ break;
+ case E_EQUAL:
+ fn(data, e->left.sym->name);
+ fn(data, "=");
+ fn(data, e->right.sym->name);
+ break;
+ case E_UNEQUAL:
+ fn(data, e->left.sym->name);
+ fn(data, "!=");
+ fn(data, e->right.sym->name);
+ break;
+ case E_OR:
+ expr_print(e->left.expr, fn, data, E_OR);
+ fn(data, " || ");
+ expr_print(e->right.expr, fn, data, E_OR);
+ break;
+ case E_AND:
+ expr_print(e->left.expr, fn, data, E_AND);
+ fn(data, " && ");
+ expr_print(e->right.expr, fn, data, E_AND);
+ break;
+ case E_CHOICE:
+ fn(data, e->right.sym->name);
+ if (e->left.expr) {
+ fn(data, " ^ ");
+ expr_print(e->left.expr, fn, data, E_CHOICE);
+ }
+ break;
+ case E_RANGE:
+ fn(data, "[");
+ fn(data, e->left.sym->name);
+ fn(data, " ");
+ fn(data, e->right.sym->name);
+ fn(data, "]");
+ break;
+ default:
+ {
+ char buf[32];
+ sprintf(buf, "<unknown type %d>", e->type);
+ fn(data, buf);
+ break;
+ }
+ }
+ if (expr_compare_type(prevtoken, e->type) > 0)
+ fn(data, ")");
+}
+
+static void expr_print_file_helper(void *data, const char *str)
+{
+ fwrite(str, strlen(str), 1, data);
+}
+
+void expr_fprint(struct expr *e, FILE *out)
+{
+ expr_print(e, expr_print_file_helper, out, E_NONE);
+}
+
+static void expr_print_gstr_helper(void *data, const char *str)
+{
+ str_append((struct gstr*)data, str);
+}
+
+void expr_gstr_print(struct expr *e, struct gstr *gs)
+{
+ expr_print(e, expr_print_gstr_helper, gs, E_NONE);
+}
