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kconfig: use hash table to reuse expressions 

Currently, every expression in Kconfig files produces a new abstract
syntax tree (AST), even if it is identical to a previously encountered
one.

Consider the following code:

    config FOO
           bool "FOO"
           depends on (A || B) && C

    config BAR
           bool "BAR"
           depends on (A || B) && C

    config BAZ
           bool "BAZ"
           depends on A || B

The "depends on" lines are similar, but currently a separate AST is
allocated for each one.

The current data structure looks like this:

  FOO->dep ==> AND        BAR->dep ==> AND        BAZ->dep ==> OR
              /   \                   /   \                   /  \
            OR     C                OR     C                 A    B
           /  \                    /  \
          A    B                  A    B

This is redundant; FOO->dep and BAR->dep have identical ASTs but
different memory instances.

We can optimize this; FOO->dep and BAR->dep can share the same AST, and
BAZ->dep can reference its sub tree.

The optimized data structure looks like this:

  FOO->dep, BAR->dep ==> AND
                        /   \
         BAZ->dep ==> OR     C
                     /  \
                    A    B

This commit introduces a hash table to keep track of allocated
expressions. If an identical expression is found, it is reused.

This does not necessarily result in memory savings, as menu_finalize()
transforms expressions without freeing up stale ones. This will be
addressed later.

One optimization that can be easily implemented is caching the
expression's value. Once FOO's dependency, (A || B) && C, is calculated,
it can be cached, eliminating the need to recalculate it for BAR.

This commit also reverts commit e983b7b17a ("kconfig/menu.c: fix
multiple references to expressions in menu_add_prop()").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2024-09-08 21:43:20 +09:00
parent 440f67ccdc
commit f93d6bfbd2
5 changed files with 170 additions and 277 deletions
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13
scripts/include/hash.h
View File

@ -12,4 +12,17 @@ static inline unsigned int hash_str(const char *s)
return hash; return hash;
} }
/* simplified version of functions from include/linux/hash.h */
#define GOLDEN_RATIO_32 0x61C88647
static inline unsigned int hash_32(unsigned int val)
{
return 0x61C88647 * val;
}
static inline unsigned int hash_ptr(const void *ptr)
{
return hash_32((unsigned int)(unsigned long)ptr);
}
#endif /* HASH_H */ #endif /* HASH_H */

381
scripts/kconfig/expr.c
View File

@ -9,45 +9,68 @@
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#include <hash.h>
#include <xalloc.h> #include <xalloc.h>
#include "internal.h"
#include "lkc.h" #include "lkc.h"
#define DEBUG_EXPR 0 #define DEBUG_EXPR 0
HASHTABLE_DEFINE(expr_hashtable, EXPR_HASHSIZE);
static struct expr *expr_eliminate_yn(struct expr *e); static struct expr *expr_eliminate_yn(struct expr *e);
/**
* expr_lookup - return the expression with the given type and sub-nodes
* This looks up an expression with the specified type and sub-nodes. If such
* an expression is found in the hash table, it is returned. Otherwise, a new
* expression node is allocated and added to the hash table.
* @type: expression type
* @l: left node
* @r: right node
* return: expression
*/
static struct expr *expr_lookup(enum expr_type type, void *l, void *r)
{
struct expr *e;
int hash;
hash = hash_32((unsigned int)type ^ hash_ptr(l) ^ hash_ptr(r));
hash_for_each_possible(expr_hashtable, e, node, hash) {
if (e->type == type && e->left._initdata == l &&
e->right._initdata == r)
return e;
}
e = xmalloc(sizeof(*e));
e->type = type;
e->left._initdata = l;
e->right._initdata = r;
hash_add(expr_hashtable, &e->node, hash);
return e;
}
struct expr *expr_alloc_symbol(struct symbol *sym) struct expr *expr_alloc_symbol(struct symbol *sym)
{ {
struct expr *e = xcalloc(1, sizeof(*e)); return expr_lookup(E_SYMBOL, sym, NULL);
e->type = E_SYMBOL;
e->left.sym = sym;
return e;
} }
struct expr *expr_alloc_one(enum expr_type type, struct expr *ce) struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
{ {
struct expr *e = xcalloc(1, sizeof(*e)); return expr_lookup(type, ce, NULL);
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 *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
{ {
struct expr *e = xcalloc(1, sizeof(*e)); return expr_lookup(type, e1, e2);
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 *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
{ {
struct expr *e = xcalloc(1, sizeof(*e)); return expr_lookup(type, s1, s2);
e->type = type;
e->left.sym = s1;
e->right.sym = s2;
return e;
} }
struct expr *expr_alloc_and(struct expr *e1, struct expr *e2) struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
@ -64,76 +87,6 @@ struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
return e2 ? expr_alloc_two(E_OR, e1, e2) : e1; return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
} }
struct expr *expr_copy(const struct expr *org)
{
struct expr *e;
if (!org)
return NULL;
e = xmalloc(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_GEQ:
case E_GTH:
case E_LEQ:
case E_LTH:
case E_UNEQUAL:
e->left.sym = org->left.sym;
e->right.sym = org->right.sym;
break;
case E_AND:
case E_OR:
e->left.expr = expr_copy(org->left.expr);
e->right.expr = expr_copy(org->right.expr);
break;
default:
fprintf(stderr, "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);
break;
case E_EQUAL:
case E_GEQ:
case E_GTH:
case E_LEQ:
case E_LTH:
case E_UNEQUAL:
break;
case E_OR:
case E_AND:
expr_free(e->left.expr);
expr_free(e->right.expr);
break;
default:
fprintf(stderr, "how to free type %d?\n", e->type);
break;
}
free(e);
}
static int trans_count; static int trans_count;
/* /*
@ -146,16 +99,24 @@ static int trans_count;
*/ */
static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2) static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
{ {
struct expr *l, *r;
/* Recurse down to leaves */ /* Recurse down to leaves */
if ((*ep1)->type == type) { if ((*ep1)->type == type) {
__expr_eliminate_eq(type, &(*ep1)->left.expr, ep2); l = (*ep1)->left.expr;
__expr_eliminate_eq(type, &(*ep1)->right.expr, ep2); r = (*ep1)->right.expr;
__expr_eliminate_eq(type, &l, ep2);
__expr_eliminate_eq(type, &r, ep2);
*ep1 = expr_alloc_two(type, l, r);
return; return;
} }
if ((*ep2)->type == type) { if ((*ep2)->type == type) {
__expr_eliminate_eq(type, ep1, &(*ep2)->left.expr); l = (*ep2)->left.expr;
__expr_eliminate_eq(type, ep1, &(*ep2)->right.expr); r = (*ep2)->right.expr;
__expr_eliminate_eq(type, ep1, &l);
__expr_eliminate_eq(type, ep1, &r);
*ep2 = expr_alloc_two(type, l, r);
return; return;
} }
@ -171,7 +132,6 @@ static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct e
/* *ep1 and *ep2 are equal leaves. Prepare them for elimination. */ /* *ep1 and *ep2 are equal leaves. Prepare them for elimination. */
trans_count++; trans_count++;
expr_free(*ep1); expr_free(*ep2);
switch (type) { switch (type) {
case E_OR: case E_OR:
*ep1 = expr_alloc_symbol(&symbol_no); *ep1 = expr_alloc_symbol(&symbol_no);
@ -271,14 +231,10 @@ bool expr_eq(struct expr *e1, struct expr *e2)
return expr_eq(e1->left.expr, e2->left.expr); return expr_eq(e1->left.expr, e2->left.expr);
case E_AND: case E_AND:
case E_OR: case E_OR:
e1 = expr_copy(e1);
e2 = expr_copy(e2);
old_count = trans_count; old_count = trans_count;
expr_eliminate_eq(&e1, &e2); expr_eliminate_eq(&e1, &e2);
res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL && res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
e1->left.sym == e2->left.sym); e1->left.sym == e2->left.sym);
expr_free(e1);
expr_free(e2);
trans_count = old_count; trans_count = old_count;
return res; return res;
case E_RANGE: case E_RANGE:
@ -297,7 +253,7 @@ bool expr_eq(struct expr *e1, struct expr *e2)
} }
/* /*
* Recursively performs the following simplifications in-place (as well as the * Recursively performs the following simplifications (as well as the
* corresponding simplifications with swapped operands): * corresponding simplifications with swapped operands):
* *
* expr && n -> n * expr && n -> n
@ -309,79 +265,39 @@ bool expr_eq(struct expr *e1, struct expr *e2)
*/ */
static struct expr *expr_eliminate_yn(struct expr *e) static struct expr *expr_eliminate_yn(struct expr *e)
{ {
struct expr *tmp; struct expr *l, *r;
if (e) switch (e->type) { if (e) switch (e->type) {
case E_AND: case E_AND:
e->left.expr = expr_eliminate_yn(e->left.expr); l = expr_eliminate_yn(e->left.expr);
e->right.expr = expr_eliminate_yn(e->right.expr); r = expr_eliminate_yn(e->right.expr);
if (e->left.expr->type == E_SYMBOL) { if (l->type == E_SYMBOL) {
if (e->left.expr->left.sym == &symbol_no) { if (l->left.sym == &symbol_no)
expr_free(e->left.expr); return l;
expr_free(e->right.expr); else if (l->left.sym == &symbol_yes)
e->type = E_SYMBOL; return r;
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;
} }
if (r->type == E_SYMBOL) {
if (r->left.sym == &symbol_no)
return r;
else if (r->left.sym == &symbol_yes)
return l;
} }
break; break;
case E_OR: case E_OR:
e->left.expr = expr_eliminate_yn(e->left.expr); l = expr_eliminate_yn(e->left.expr);
e->right.expr = expr_eliminate_yn(e->right.expr); r = expr_eliminate_yn(e->right.expr);
if (e->left.expr->type == E_SYMBOL) { if (l->type == E_SYMBOL) {
if (e->left.expr->left.sym == &symbol_no) { if (l->left.sym == &symbol_no)
free(e->left.expr); return r;
tmp = e->right.expr; else if (l->left.sym == &symbol_yes)
*e = *(e->right.expr); return l;
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;
} }
if (r->type == E_SYMBOL) {
if (r->left.sym == &symbol_no)
return l;
else if (r->left.sym == &symbol_yes)
return r;
} }
break; break;
default: default:
@ -399,7 +315,7 @@ static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
struct symbol *sym1, *sym2; struct symbol *sym1, *sym2;
if (expr_eq(e1, e2)) if (expr_eq(e1, e2))
return expr_copy(e1); return e1;
if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT) if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
return NULL; return NULL;
if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT) if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
@ -464,7 +380,7 @@ static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
struct symbol *sym1, *sym2; struct symbol *sym1, *sym2;
if (expr_eq(e1, e2)) if (expr_eq(e1, e2))
return expr_copy(e1); return e1;
if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT) if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
return NULL; return NULL;
if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT) if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
@ -561,18 +477,24 @@ static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
*/ */
static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2) static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
{ {
struct expr *tmp; struct expr *tmp, *l, *r;
/* Recurse down to leaves */ /* Recurse down to leaves */
if ((*ep1)->type == type) { if ((*ep1)->type == type) {
expr_eliminate_dups1(type, &(*ep1)->left.expr, ep2); l = (*ep1)->left.expr;
expr_eliminate_dups1(type, &(*ep1)->right.expr, ep2); r = (*ep1)->right.expr;
expr_eliminate_dups1(type, &l, ep2);
expr_eliminate_dups1(type, &r, ep2);
*ep1 = expr_alloc_two(type, l, r);
return; return;
} }
if ((*ep2)->type == type) { if ((*ep2)->type == type) {
expr_eliminate_dups1(type, ep1, &(*ep2)->left.expr); l = (*ep2)->left.expr;
expr_eliminate_dups1(type, ep1, &(*ep2)->right.expr); r = (*ep2)->right.expr;
expr_eliminate_dups1(type, ep1, &l);
expr_eliminate_dups1(type, ep1, &r);
*ep2 = expr_alloc_two(type, l, r);
return; return;
} }
@ -582,7 +504,6 @@ static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct
case E_OR: case E_OR:
tmp = expr_join_or(*ep1, *ep2); tmp = expr_join_or(*ep1, *ep2);
if (tmp) { if (tmp) {
expr_free(*ep1); expr_free(*ep2);
*ep1 = expr_alloc_symbol(&symbol_no); *ep1 = expr_alloc_symbol(&symbol_no);
*ep2 = tmp; *ep2 = tmp;
trans_count++; trans_count++;
@ -591,7 +512,6 @@ static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct
case E_AND: case E_AND:
tmp = expr_join_and(*ep1, *ep2); tmp = expr_join_and(*ep1, *ep2);
if (tmp) { if (tmp) {
expr_free(*ep1); expr_free(*ep2);
*ep1 = expr_alloc_symbol(&symbol_yes); *ep1 = expr_alloc_symbol(&symbol_yes);
*ep2 = tmp; *ep2 = tmp;
trans_count++; trans_count++;
@ -621,12 +541,15 @@ struct expr *expr_eliminate_dups(struct expr *e)
oldcount = trans_count; oldcount = trans_count;
do { do {
struct expr *l, *r;
trans_count = 0; trans_count = 0;
switch (e->type) { switch (e->type) {
case E_OR: case E_AND: case E_OR: case E_AND:
e->left.expr = expr_eliminate_dups(e->left.expr); l = expr_eliminate_dups(e->left.expr);
e->right.expr = expr_eliminate_dups(e->right.expr); r = expr_eliminate_dups(e->right.expr);
expr_eliminate_dups1(e->type, &e->left.expr, &e->right.expr); expr_eliminate_dups1(e->type, &l, &r);
e = expr_alloc_two(e->type, l, r);
default: default:
; ;
} }
@ -668,8 +591,6 @@ struct expr *expr_eliminate_dups(struct expr *e)
*/ */
struct expr *expr_transform(struct expr *e) struct expr *expr_transform(struct expr *e)
{ {
struct expr *tmp;
if (!e) if (!e)
return NULL; return NULL;
switch (e->type) { switch (e->type) {
@ -682,8 +603,9 @@ struct expr *expr_transform(struct expr *e)
case E_SYMBOL: case E_SYMBOL:
break; break;
default: default:
e->left.expr = expr_transform(e->left.expr); e = expr_alloc_two(e->type,
e->right.expr = expr_transform(e->right.expr); expr_transform(e->left.expr),
expr_transform(e->right.expr));
} }
switch (e->type) { switch (e->type) {
@ -692,23 +614,18 @@ struct expr *expr_transform(struct expr *e)
break; break;
if (e->right.sym == &symbol_no) { if (e->right.sym == &symbol_no) {
// A=n -> !A // A=n -> !A
e->type = E_NOT; e = expr_alloc_one(E_NOT, expr_alloc_symbol(e->left.sym));
e->left.expr = expr_alloc_symbol(e->left.sym);
e->right.sym = NULL;
break; break;
} }
if (e->right.sym == &symbol_mod) { if (e->right.sym == &symbol_mod) {
// A=m -> n // A=m -> n
printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name); printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
e->type = E_SYMBOL; e = expr_alloc_symbol(&symbol_no);
e->left.sym = &symbol_no;
e->right.sym = NULL;
break; break;
} }
if (e->right.sym == &symbol_yes) { if (e->right.sym == &symbol_yes) {
// A=y -> A // A=y -> A
e->type = E_SYMBOL; e = expr_alloc_symbol(e->left.sym);
e->right.sym = NULL;
break; break;
} }
break; break;
@ -717,23 +634,18 @@ struct expr *expr_transform(struct expr *e)
break; break;
if (e->right.sym == &symbol_no) { if (e->right.sym == &symbol_no) {
// A!=n -> A // A!=n -> A
e->type = E_SYMBOL; e = expr_alloc_symbol(e->left.sym);
e->right.sym = NULL;
break; break;
} }
if (e->right.sym == &symbol_mod) { if (e->right.sym == &symbol_mod) {
// A!=m -> y // A!=m -> y
printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name); printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
e->type = E_SYMBOL; e = expr_alloc_symbol(&symbol_yes);
e->left.sym = &symbol_yes;
e->right.sym = NULL;
break; break;
} }
if (e->right.sym == &symbol_yes) { if (e->right.sym == &symbol_yes) {
// A!=y -> !A // A!=y -> !A
e->type = E_NOT; e = expr_alloc_one(E_NOT, e->left.expr);
e->left.expr = expr_alloc_symbol(e->left.sym);
e->right.sym = NULL;
break; break;
} }
break; break;
@ -741,82 +653,51 @@ struct expr *expr_transform(struct expr *e)
switch (e->left.expr->type) { switch (e->left.expr->type) {
case E_NOT: case E_NOT:
// !!A -> A // !!A -> A
tmp = e->left.expr->left.expr; e = e->left.expr->left.expr;
free(e->left.expr);
free(e);
e = tmp;
e = expr_transform(e);
break; break;
case E_EQUAL: case E_EQUAL:
case E_UNEQUAL: case E_UNEQUAL:
// !(A=B) -> A!=B // !(A=B) -> A!=B
tmp = e->left.expr; e = expr_alloc_comp(e->left.expr->type == E_EQUAL ? E_UNEQUAL : E_EQUAL,
free(e); e->left.expr->left.sym,
e = tmp; e->left.expr->right.sym);
e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
break; break;
case E_LEQ: case E_LEQ:
case E_GEQ: case E_GEQ:
// !(A<=B) -> A>B // !(A<=B) -> A>B
tmp = e->left.expr; e = expr_alloc_comp(e->left.expr->type == E_LEQ ? E_GTH : E_LTH,
free(e); e->left.expr->left.sym,
e = tmp; e->left.expr->right.sym);
e->type = e->type == E_LEQ ? E_GTH : E_LTH;
break; break;
case E_LTH: case E_LTH:
case E_GTH: case E_GTH:
// !(A<B) -> A>=B // !(A<B) -> A>=B
tmp = e->left.expr; e = expr_alloc_comp(e->left.expr->type == E_LTH ? E_GEQ : E_LEQ,
free(e); e->left.expr->left.sym,
e = tmp; e->left.expr->right.sym);
e->type = e->type == E_LTH ? E_GEQ : E_LEQ;
break; break;
case E_OR: case E_OR:
// !(A || B) -> !A && !B // !(A || B) -> !A && !B
tmp = e->left.expr; e = expr_alloc_and(expr_alloc_one(E_NOT, e->left.expr->left.expr),
e->type = E_AND; expr_alloc_one(E_NOT, e->left.expr->right.expr));
e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
tmp->type = E_NOT;
tmp->right.expr = NULL;
e = expr_transform(e); e = expr_transform(e);
break; break;
case E_AND: case E_AND:
// !(A && B) -> !A || !B // !(A && B) -> !A || !B
tmp = e->left.expr; e = expr_alloc_or(expr_alloc_one(E_NOT, e->left.expr->left.expr),
e->type = E_OR; expr_alloc_one(E_NOT, e->left.expr->right.expr));
e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
tmp->type = E_NOT;
tmp->right.expr = NULL;
e = expr_transform(e); e = expr_transform(e);
break; break;
case E_SYMBOL: case E_SYMBOL:
if (e->left.expr->left.sym == &symbol_yes) { if (e->left.expr->left.sym == &symbol_yes)
// !'y' -> 'n' // !'y' -> 'n'
tmp = e->left.expr; e = expr_alloc_symbol(&symbol_no);
free(e); else if (e->left.expr->left.sym == &symbol_mod)
e = tmp;
e->type = E_SYMBOL;
e->left.sym = &symbol_no;
break;
}
if (e->left.expr->left.sym == &symbol_mod) {
// !'m' -> 'm' // !'m' -> 'm'
tmp = e->left.expr; e = expr_alloc_symbol(&symbol_mod);
free(e); else if (e->left.expr->left.sym == &symbol_no)
e = tmp;
e->type = E_SYMBOL;
e->left.sym = &symbol_mod;
break;
}
if (e->left.expr->left.sym == &symbol_no) {
// !'n' -> 'y' // !'n' -> 'y'
tmp = e->left.expr; e = expr_alloc_symbol(&symbol_yes);
free(e);
e = tmp;
e->type = E_SYMBOL;
e->left.sym = &symbol_yes;
break;
}
break; break;
default: default:
; ;
@ -940,18 +821,18 @@ struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symb
case E_EQUAL: case E_EQUAL:
if (type == E_EQUAL) { if (type == E_EQUAL) {
if (sym == &symbol_yes) if (sym == &symbol_yes)
return expr_copy(e); return e;
if (sym == &symbol_mod) if (sym == &symbol_mod)
return expr_alloc_symbol(&symbol_no); return expr_alloc_symbol(&symbol_no);
if (sym == &symbol_no) if (sym == &symbol_no)
return expr_alloc_one(E_NOT, expr_copy(e)); return expr_alloc_one(E_NOT, e);
} else { } else {
if (sym == &symbol_yes) if (sym == &symbol_yes)
return expr_alloc_one(E_NOT, expr_copy(e)); return expr_alloc_one(E_NOT, e);
if (sym == &symbol_mod) if (sym == &symbol_mod)
return expr_alloc_symbol(&symbol_yes); return expr_alloc_symbol(&symbol_yes);
if (sym == &symbol_no) if (sym == &symbol_no)
return expr_copy(e); return e;
} }
break; break;
case E_SYMBOL: case E_SYMBOL:

16
scripts/kconfig/expr.h
View File

@ -29,11 +29,21 @@ enum expr_type {
}; };
union expr_data { union expr_data {
struct expr *expr; struct expr * const expr;
struct symbol *sym; struct symbol * const sym;
void *_initdata;
}; };
/**
* struct expr - expression
*
* @node: link node for the hash table
* @type: expressoin type
* @left: left node
* @right: right node
*/
struct expr { struct expr {
struct hlist_node node;
enum expr_type type; enum expr_type type;
union expr_data left, right; union expr_data left, right;
}; };
@ -275,8 +285,6 @@ struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e
struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2); struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2);
struct expr *expr_alloc_and(struct expr *e1, struct expr *e2); struct expr *expr_alloc_and(struct expr *e1, struct expr *e2);
struct expr *expr_alloc_or(struct expr *e1, struct expr *e2); struct expr *expr_alloc_or(struct expr *e1, struct expr *e2);
struct expr *expr_copy(const struct expr *org);
void expr_free(struct expr *e);
void expr_eliminate_eq(struct expr **ep1, struct expr **ep2); void expr_eliminate_eq(struct expr **ep1, struct expr **ep2);
bool expr_eq(struct expr *e1, struct expr *e2); bool expr_eq(struct expr *e1, struct expr *e2);
tristate expr_calc_value(struct expr *e); tristate expr_calc_value(struct expr *e);

4
scripts/kconfig/internal.h
View File

@ -11,6 +11,10 @@ extern HASHTABLE_DECLARE(sym_hashtable, SYMBOL_HASHSIZE);
#define for_all_symbols(sym) \ #define for_all_symbols(sym) \
hash_for_each(sym_hashtable, sym, node) hash_for_each(sym_hashtable, sym, node)
#define EXPR_HASHSIZE (1U << 14)
extern HASHTABLE_DECLARE(expr_hashtable, EXPR_HASHSIZE);
struct menu; struct menu;
extern struct menu *current_menu, *current_entry; extern struct menu *current_menu, *current_entry;

33
scripts/kconfig/menu.c
View File

@ -107,12 +107,13 @@ static struct expr *rewrite_m(struct expr *e)
switch (e->type) { switch (e->type) {
case E_NOT: case E_NOT:
e->left.expr = rewrite_m(e->left.expr); e = expr_alloc_one(E_NOT, rewrite_m(e->left.expr));
break; break;
case E_OR: case E_OR:
case E_AND: case E_AND:
e->left.expr = rewrite_m(e->left.expr); e = expr_alloc_two(e->type,
e->right.expr = rewrite_m(e->right.expr); rewrite_m(e->left.expr),
rewrite_m(e->right.expr));
break; break;
case E_SYMBOL: case E_SYMBOL:
/* change 'm' into 'm' && MODULES */ /* change 'm' into 'm' && MODULES */
@ -192,21 +193,11 @@ struct property *menu_add_prompt(enum prop_type type, const char *prompt,
struct menu *menu = current_entry; struct menu *menu = current_entry;
while ((menu = menu->parent) != NULL) { while ((menu = menu->parent) != NULL) {
struct expr *dup_expr;
if (!menu->visibility) if (!menu->visibility)
continue; continue;
/*
* Do not add a reference to the menu's visibility
* expression but use a copy of it. Otherwise the
* expression reduction functions will modify
* expressions that have multiple references which
* can cause unwanted side effects.
*/
dup_expr = expr_copy(menu->visibility);
prop->visible.expr = expr_alloc_and(prop->visible.expr, prop->visible.expr = expr_alloc_and(prop->visible.expr,
dup_expr); menu->visibility);
} }
} }
@ -322,7 +313,7 @@ static void _menu_finalize(struct menu *parent, bool inside_choice)
*/ */
basedep = rewrite_m(menu->dep); basedep = rewrite_m(menu->dep);
basedep = expr_transform(basedep); basedep = expr_transform(basedep);
basedep = expr_alloc_and(expr_copy(parent->dep), basedep); basedep = expr_alloc_and(parent->dep, basedep);
basedep = expr_eliminate_dups(basedep); basedep = expr_eliminate_dups(basedep);
menu->dep = basedep; menu->dep = basedep;
@ -366,7 +357,7 @@ static void _menu_finalize(struct menu *parent, bool inside_choice)
*/ */
dep = rewrite_m(prop->visible.expr); dep = rewrite_m(prop->visible.expr);
dep = expr_transform(dep); dep = expr_transform(dep);
dep = expr_alloc_and(expr_copy(basedep), dep); dep = expr_alloc_and(basedep, dep);
dep = expr_eliminate_dups(dep); dep = expr_eliminate_dups(dep);
prop->visible.expr = dep; prop->visible.expr = dep;
@ -377,11 +368,11 @@ static void _menu_finalize(struct menu *parent, bool inside_choice)
if (prop->type == P_SELECT) { if (prop->type == P_SELECT) {
struct symbol *es = prop_get_symbol(prop); struct symbol *es = prop_get_symbol(prop);
es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr, es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr,
expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep))); expr_alloc_and(expr_alloc_symbol(menu->sym), dep));
} else if (prop->type == P_IMPLY) { } else if (prop->type == P_IMPLY) {
struct symbol *es = prop_get_symbol(prop); struct symbol *es = prop_get_symbol(prop);
es->implied.expr = expr_alloc_or(es->implied.expr, es->implied.expr = expr_alloc_or(es->implied.expr,
expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep))); expr_alloc_and(expr_alloc_symbol(menu->sym), dep));
} }
} }
} }
@ -441,22 +432,18 @@ static void _menu_finalize(struct menu *parent, bool inside_choice)
*/ */
dep = expr_trans_compare(dep, E_UNEQUAL, &symbol_no); dep = expr_trans_compare(dep, E_UNEQUAL, &symbol_no);
dep = expr_eliminate_dups(expr_transform(dep)); dep = expr_eliminate_dups(expr_transform(dep));
dep2 = expr_copy(basedep); dep2 = basedep;
expr_eliminate_eq(&dep, &dep2); expr_eliminate_eq(&dep, &dep2);
expr_free(dep);
if (!expr_is_yes(dep2)) { if (!expr_is_yes(dep2)) {
/* Not superset, quit */ /* Not superset, quit */
expr_free(dep2);
break; break;
} }
/* Superset, put in submenu */ /* Superset, put in submenu */
expr_free(dep2);
next: next:
_menu_finalize(menu, false); _menu_finalize(menu, false);
menu->parent = parent; menu->parent = parent;
last_menu = menu; last_menu = menu;
} }
expr_free(basedep);
if (last_menu) { if (last_menu) {
parent->list = parent->next; parent->list = parent->next;
parent->next = last_menu->next; parent->next = last_menu->next;