From 3fb6326fc36c69aa0b66de4823b116d7c0a9486c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= <cynerd@email.cz>
Date: Fri, 1 May 2015 20:55:43 +0200
Subject: parse_kconfig rewriten

parse_kconfig should now generate full dependency.
It is not transforming whole expression to CNF, but only pairs.
---
 scripts/parse_kconfig/cnfbuild.c | 359 +++++++++++++--------------------------
 1 file changed, 115 insertions(+), 244 deletions(-)

(limited to 'scripts/parse_kconfig/cnfbuild.c')

diff --git a/scripts/parse_kconfig/cnfbuild.c b/scripts/parse_kconfig/cnfbuild.c
index f9dd15f..398a934 100644
--- a/scripts/parse_kconfig/cnfbuild.c
+++ b/scripts/parse_kconfig/cnfbuild.c
@@ -1,272 +1,143 @@
 #include "cnfbuild.h"
 
-struct cnfexpr *kconfig_expr(struct symlist *sl, struct expr *expr) {
-    struct stck {
-        struct expr *expr;
-        struct cnfexpr *cnf;
-    };
-    struct expr **back;
-    int back_size = 2, back_pos = -1;
-    back = malloc((unsigned) back_size * sizeof(struct expr *));
-    struct stck *stack;
-    int stack_size = 2, stack_pos = -1;
-    stack = malloc((unsigned) stack_size * sizeof(struct stck));
-    struct cnfexpr *rtn = NULL;
+struct stck {
+    struct boolexpr **stack;
+    size_t size, pos;
+};
+
+struct stck *stack_create();
+void stack_push(struct stck *s, struct boolexpr *b);
+struct boolexpr *stack_pop(struct stck *s);
+
+void cnf_and(struct symlist *sl, struct boolexpr *bl);
+void cnf_or(struct symlist *sl, struct boolexpr *bl);
+void cnf_not(struct symlist *sl, struct boolexpr *bl);
+
+void cnf_boolexpr(struct symlist *sl, struct boolexpr *bl) {
+    if (bl->type == BT_TRUE) {
+        // Term is always true. No write required.
+        return;
+    } else if (bl->type == BT_FALSE) {
+        fprintf(stderr,
+                "E: Trying to write false term. This shouldn't happen.\n");
+        exit(6);
+    }
 
-    while (expr != NULL) {
-        if ((back_pos >= 0 && back[back_pos] != expr) || back_pos < 0) {
-            if (++back_pos >= back_size) {
-                back_size *= 2;
-                back =
-                    realloc(back,
-                            (unsigned) back_size * sizeof(struct expr *));
-            }
-            back[back_pos] = expr;
-        }
-        switch (expr->type) {
-        case E_SYMBOL:
-            rtn = cnf_sym(sl, expr->left.sym);
-            goto go_up;
-        case E_NOT:
-            if (rtn == NULL)
-                expr = expr->left.expr;
-            else {
-                rtn = cnf_not(sl, rtn);
-                goto go_up;
+    struct stck *stack = stack_create();
+    while (bl != NULL) {
+        switch (bl->type) {
+        case BT_NOT:
+            if (bl->left->id != 0) {
+                cnf_not(sl, bl);
+                bl = stack_pop(stack);
+            } else {
+                stack_push(stack, bl);
+                bl = bl->left;
             }
             break;
-        case E_OR:
-        case E_AND:
-            if (stack_pos < 0 || stack[stack_pos].expr != expr) {
-                if (rtn == NULL)
-                    expr = expr->left.expr;
-                else {
-                    if (stack_size >= ++stack_pos) {
-                        stack_size *= 2;
-                        stack =
-                            realloc(stack,
-                                    (unsigned) stack_size *
-                                    sizeof(struct stck *));
+        case BT_AND:
+        case BT_OR:
+            if (bl->left->id != 0) {
+                if (bl->right->id != 0) {
+                    if (bl->type == BT_OR) {
+                        cnf_or(sl, bl);
+                        bl = stack_pop(stack);
+                    } else {    /* BT_AND */
+                        cnf_and(sl, bl);
+                        bl = stack_pop(stack);
                     }
-                    stack[stack_pos].expr = expr;
-                    stack[stack_pos].cnf = rtn;
-                    expr = expr->right.expr;
-                    rtn = NULL;
+                } else {
+                    stack_push(stack, bl);
+                    bl = bl->right;
                 }
             } else {
-                if (expr->type == E_OR)
-                    rtn = cnf_or(sl, stack[stack_pos].cnf, rtn);
-                else
-                    rtn = cnf_and(sl, stack[stack_pos].cnf, rtn);
-                stack_pos--;
-                goto go_up;
+                stack_push(stack, bl);
+                bl = bl->left;
             }
             break;
-        case E_EQUAL:
-            rtn = cnf_eql(sl, expr->left.sym, expr->right.sym);
-            goto go_up;
-        case E_UNEQUAL:
-            rtn =
-                cnf_not(sl, cnf_eql(sl, expr->left.sym, expr->right.sym));
-            goto go_up;
         default:
-            fprintf(stderr, "ERROR: Unknown expression type.\n");
+            bl = stack_pop(stack);
+            break;
         }
-        continue;
-
-      go_up:
-        if (--back_pos >= 0)
-            expr = back[back_pos];
-        else
-            expr = NULL;
     }
-
-    free(back);
-    free(stack);
-
-    return rtn;
 }
 
-struct cnfexpr *cnfexpr_true(struct symlist *sl) {
-    struct cnfexpr *rtn;
-    rtn = malloc(sizeof(struct cnfexpr));
-    rtn->type = CT_TRUE;
-    rtn->id = 0;
-    rtn->out = NULL;
+struct stck *stack_create() {
+    struct stck *rtn;
+    rtn = malloc(sizeof(struct stck));
+    rtn->size = 2;
+    rtn->pos = 0;
+    rtn->stack = malloc(rtn->size * sizeof(struct boolexpr *));
     return rtn;
 }
 
-struct cnfexpr *cnfexpr_false(struct symlist *sl) {
-    struct cnfexpr *rtn;
-    rtn = malloc(sizeof(struct cnfexpr));
-    rtn->type = CT_FALSE;
-    rtn->id = 0;
-    rtn->out = NULL;
-    return rtn;
-}
-
-struct cnfexpr *cnf_sym(struct symlist *sl, struct symbol *sym) {
-    struct cnfexpr *rtn;
-    rtn = malloc(sizeof(struct cnfexpr));
-    rtn->type = CT_EXPR;
-    rtn->id = symlist_id(sym->name);
-    rtn->out = NULL;
-    if (rtn->id == 0)
-        rtn->type = CT_FALSE;
-    return rtn;
-}
-
-struct cnfexpr *cnf_eql(struct symlist *sl, struct symbol *sym1,
-                        struct symbol *sym2) {
-    if (!strcmp(sym2->name, "m")) {
-        struct cnfexpr *fls = malloc(sizeof(struct cnfexpr));
-        fls->type = CT_FALSE;
-        return fls;
-    }
-    if (!strcmp(sym2->name, "n"))
-        return cnf_not(sl, cnf_sym(sl, sym1));
-    if (!strcmp(sym2->name, "y"))
-        return cnf_sym(sl, sym1);
-
-    // sym1 <-> sym2
-    // (!sym1 || sym2) && (sym1 || !sym2)
-    return cnf_and(sl,
-                   cnf_or(sl, cnf_not(sl, cnf_sym(sl, sym1)),
-                          cnf_sym(sl, sym2)), cnf_or(sl, cnf_sym(sl,
-                                                                 sym1),
-                                                     cnf_not(sl,
-                                                             cnf_sym
-                                                             (sl, sym2))));
-}
-
-struct cnfexpr *cnf_or(struct symlist *sl, struct cnfexpr *e1,
-                       struct cnfexpr *e2) {
-    switch (e1->type) {
-    case CT_TRUE:
-        cnfexpr_free(e2);
-        return e1;
-    case CT_FALSE:
-        cnfexpr_free(e1);
-        return e2;
-    case CT_EXPR:
-        switch (e2->type) {
-        case CT_TRUE:
-            cnfexpr_free(e1);
-            return e2;
-        case CT_FALSE:
-            cnfexpr_free(e2);
-            return e1;
-        case CT_EXPR:
-            break;
-        }
-        break;
+void stack_push(struct stck *s, struct boolexpr *b) {
+    if (++(s->pos) >= s->size) {
+        s->size *= 2;
+        s->stack = realloc(s->stack, s->size * sizeof(struct boolexpr *));
     }
-
-    unsigned newid = (unsigned) symlist_adddummy(sl);
-    e1->out = output_rules_joinexpr(e1->out, e2->out);
-    if (e1->out == NULL)
-        e1->out = output_rules_newexpr();
-
-    // rtn <-> (e1 || e2)
-    // (!rtn || e1 || e2) && (rtn || !e1) && (rtn || !e2)
-    output_rules_symbol(e1->out, -(int) newid);
-    output_rules_symbol(e1->out, (int) e1->id);
-    output_rules_symbol(e1->out, (int) e2->id);
-    output_rules_endterm(e1->out);
-    output_rules_symbol(e1->out, (int) rtn->id);
-    output_rules_symbol(e1->out, -(int) e1->id);
-    output_rules_endterm(e1->out);
-    output_rules_symbol(e1->out, (int) rtn->id);
-    output_rules_symbol(e1->out, -(int) e2->id);
-    output_rules_endterm(e1->out);
-
-    cnfexpr_free(e2);
-    e1->id = newid;
-    return e1;
+    s->stack[s->pos - 1] = b;
 }
 
-struct cnfexpr *cnf_and(struct symlist *sl, struct cnfexpr *e1,
-                        struct cnfexpr *e2) {
-    switch (e1->type) {
-    case CT_FALSE:
-        cnfexpr_free(e2);
-        return e1;
-    case CT_TRUE:
-        cnfexpr_free(e1);
-        return e2;
-    case CT_EXPR:
-        switch (e2->type) {
-        case CT_FALSE:
-            cnfexpr_free(e1);
-            return e2;
-        case CT_TRUE:
-            cnfexpr_free(e2);
-            return e1;
-        case CT_EXPR:
-            break;
-        }
-        break;
-    }
-
-    unsigned newid = (unsigned) symlist_adddummy(sl);
-    e1->out = output_rules_joinexpr(e1->out, e2->out);
-    if (e1->out == NULL)
-        e1->out = output_rules_newexpr();
-
-    // rtn <-> (e1 && e2)
-    // (rtn || !e1 || !e2) && (!rtn || e1) && (!rtn || e2)
-    output_rules_symbol(e1->out, (int) rtn->id);
-    output_rules_symbol(e1->out, -(int) e1->id);
-    output_rules_symbol(e1->out, -(int) e2->id);
-    output_rules_endterm(e1->out);
-    output_rules_symbol(e1->out, -(int) rtn->id);
-    output_rules_symbol(e1->out, (int) e1->id);
-    output_rules_endterm(e1->out);
-    output_rules_symbol(e1->out, -(int) rtn->id);
-    output_rules_symbol(e1->out, (int) e2->id);
-    output_rules_endterm(e1->out);
-
-    cnfexpr_free(e2);
-    e1->id = newid;
-    return e1;
+inline struct boolexpr *stack_pop(struct stck *s) {
+    if (s->pos > 0)
+        return s->stack[--(s->pos)];
+    else
+        return NULL;
 }
 
-struct cnfexpr *cnf_not(struct symlist *sl, struct cnfexpr *e) {
-    switch (e->type) {
-    case CT_FALSE:
-        e->type = CT_TRUE;
-        return e;
-    case CT_TRUE:
-        e->type = CT_FALSE;
-        return e;
-    case CT_EXPR:
-        break;
-    }
-    unsigned newid = (unsigned) symlist_adddummy(sl);
-
-    // rtn <-> !e
-    // (rtn || e) && (!rtn || !e)
-    output_rules_symbol(e->out, (int) newid);
-    output_rules_symbol(e->out, (int) e->id);
-    output_rules_endterm(e->out);
-    output_rules_symbol(e->out, -(int) newid);
-    output_rules_symbol(e->out, -(int) e->id);
-    output_rules_endterm(e->out);
-
-    e->id = newid;
-    return e;
+void cnf_and(struct symlist *sl, struct boolexpr *bl) {
+    if (bl->id != 0)
+        return;
+    bl->id = symlist_adddummy(sl);
+    // bl->id <-> (bl->left->id && bl->right->id)
+    //
+    // (bl->id || !bl->left->id || !bl->right->id) &&
+    // (!bl->id || bl->left->id) &&
+    // (!bl->id || bl->right->id)
+    output_rules_symbol((int) bl->id);
+    output_rules_symbol(-(int) bl->left->id);
+    output_rules_symbol(-(int) bl->right->id);
+    output_rules_endterm();
+    output_rules_symbol(-(int) bl->id);
+    output_rules_symbol((int) bl->left->id);
+    output_rules_endterm();
+    output_rules_symbol(-(int) bl->id);
+    output_rules_symbol((int) bl->right->id);
+    output_rules_endterm();
 }
 
-struct cnfexpr *cnfexpr_copy(struct cnfexpr *e) {
-    struct cnfexpr *rtn;
-    rtn = malloc(sizeof(struct cnfexpr));
-    rtn->type = e->type;
-    rtn->id = e->id;
-    rtn->out = output_rules_copycnf(e->out);
-    return rtn;
+void cnf_or(struct symlist *sl, struct boolexpr *bl) {
+    if (bl->id != 0)
+        return;
+    bl->id = symlist_adddummy(sl);
+    // bl->id <-> (bl->left->id || bl->right->id)
+    //
+    // (!bl->id || bl->left->id || bl->right->id) &&
+    // (bl->id || !bl->left->id) &&
+    // (bl->id || !bl->right->id)
+    output_rules_symbol(-(int) bl->id);
+    output_rules_symbol((int) bl->left->id);
+    output_rules_symbol((int) bl->right->id);
+    output_rules_endterm();
+    output_rules_symbol((int) bl->id);
+    output_rules_symbol(-(int) bl->left->id);
+    output_rules_endterm();
+    output_rules_symbol((int) bl->id);
+    output_rules_symbol(-(int) bl->right->id);
+    output_rules_endterm();
 }
 
-void cnfexpr_free(struct cnfexpr *e) {
-    output_rules_freexpr(e->out);
-    free(e);
+void cnf_not(struct symlist *sl, struct boolexpr *bl) {
+    if (bl->id != 0)
+        return;
+    bl->id = symlist_adddummy(sl);
+    // bl->id <-> !bl->left->id
+    // (bl->id || bl->left->id) && (!bl->id || !bl->left->id)
+    output_rules_symbol((int) bl->id);
+    output_rules_symbol((int) bl->left->id);
+    output_rules_endterm();
+    output_rules_symbol(-(int) bl->id);
+    output_rules_symbol(-(int) bl->left->id);
+    output_rules_endterm();
 }
-- 
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