From f93d6bfbd2f74d79041c153a59df5336f6e9a14a Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 8 Sep 2024 21:43:20 +0900 Subject: [PATCH] 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 e983b7b17ad1 ("kconfig/menu.c: fix multiple references to expressions in menu_add_prop()"). Signed-off-by: Masahiro Yamada --- scripts/include/hash.h | 13 ++ scripts/kconfig/expr.c | 381 +++++++++++++------------------------ scripts/kconfig/expr.h | 16 +- scripts/kconfig/internal.h | 4 + scripts/kconfig/menu.c | 33 +--- 5 files changed, 170 insertions(+), 277 deletions(-) diff --git a/scripts/include/hash.h b/scripts/include/hash.h index ce2bc43b308b..efa904368a62 100644 --- a/scripts/include/hash.h +++ b/scripts/include/hash.h @@ -12,4 +12,17 @@ static inline unsigned int hash_str(const char *s) 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 */ diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c index 5b826d197f12..476dcaa9078e 100644 --- a/scripts/kconfig/expr.c +++ b/scripts/kconfig/expr.c @@ -9,45 +9,68 @@ #include #include +#include #include +#include "internal.h" #include "lkc.h" #define DEBUG_EXPR 0 +HASHTABLE_DEFINE(expr_hashtable, EXPR_HASHSIZE); + 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 *e = xcalloc(1, sizeof(*e)); - e->type = E_SYMBOL; - e->left.sym = sym; - return e; + return expr_lookup(E_SYMBOL, sym, NULL); } struct expr *expr_alloc_one(enum expr_type type, struct expr *ce) { - struct expr *e = xcalloc(1, sizeof(*e)); - e->type = type; - e->left.expr = ce; - return e; + return expr_lookup(type, ce, NULL); } struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2) { - struct expr *e = xcalloc(1, sizeof(*e)); - e->type = type; - e->left.expr = e1; - e->right.expr = e2; - return e; + return expr_lookup(type, e1, e2); } struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2) { - struct expr *e = xcalloc(1, sizeof(*e)); - e->type = type; - e->left.sym = s1; - e->right.sym = s2; - return e; + return expr_lookup(type, s1, s2); } 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; } -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; /* @@ -146,16 +99,24 @@ static int trans_count; */ static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2) { + struct expr *l, *r; + /* Recurse down to leaves */ if ((*ep1)->type == type) { - __expr_eliminate_eq(type, &(*ep1)->left.expr, ep2); - __expr_eliminate_eq(type, &(*ep1)->right.expr, ep2); + l = (*ep1)->left.expr; + r = (*ep1)->right.expr; + __expr_eliminate_eq(type, &l, ep2); + __expr_eliminate_eq(type, &r, ep2); + *ep1 = expr_alloc_two(type, l, r); return; } if ((*ep2)->type == type) { - __expr_eliminate_eq(type, ep1, &(*ep2)->left.expr); - __expr_eliminate_eq(type, ep1, &(*ep2)->right.expr); + l = (*ep2)->left.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; } @@ -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. */ trans_count++; - expr_free(*ep1); expr_free(*ep2); switch (type) { case E_OR: *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); 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_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): * * 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) { - struct expr *tmp; + struct expr *l, *r; 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; - } + l = expr_eliminate_yn(e->left.expr); + r = expr_eliminate_yn(e->right.expr); + if (l->type == E_SYMBOL) { + if (l->left.sym == &symbol_no) + return l; + else if (l->left.sym == &symbol_yes) + return r; } - 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; 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; - } + l = expr_eliminate_yn(e->left.expr); + r = expr_eliminate_yn(e->right.expr); + if (l->type == E_SYMBOL) { + if (l->left.sym == &symbol_no) + return r; + else if (l->left.sym == &symbol_yes) + return l; } - 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; default: @@ -399,7 +315,7 @@ static struct expr *expr_join_or(struct expr *e1, struct expr *e2) struct symbol *sym1, *sym2; 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) return NULL; 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; 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) return NULL; 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) { - struct expr *tmp; + struct expr *tmp, *l, *r; /* Recurse down to leaves */ if ((*ep1)->type == type) { - expr_eliminate_dups1(type, &(*ep1)->left.expr, ep2); - expr_eliminate_dups1(type, &(*ep1)->right.expr, ep2); + l = (*ep1)->left.expr; + r = (*ep1)->right.expr; + expr_eliminate_dups1(type, &l, ep2); + expr_eliminate_dups1(type, &r, ep2); + *ep1 = expr_alloc_two(type, l, r); return; } if ((*ep2)->type == type) { - expr_eliminate_dups1(type, ep1, &(*ep2)->left.expr); - expr_eliminate_dups1(type, ep1, &(*ep2)->right.expr); + l = (*ep2)->left.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; } @@ -582,7 +504,6 @@ static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct case E_OR: tmp = expr_join_or(*ep1, *ep2); if (tmp) { - expr_free(*ep1); expr_free(*ep2); *ep1 = expr_alloc_symbol(&symbol_no); *ep2 = tmp; trans_count++; @@ -591,7 +512,6 @@ static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct case E_AND: tmp = expr_join_and(*ep1, *ep2); if (tmp) { - expr_free(*ep1); expr_free(*ep2); *ep1 = expr_alloc_symbol(&symbol_yes); *ep2 = tmp; trans_count++; @@ -621,12 +541,15 @@ struct expr *expr_eliminate_dups(struct expr *e) oldcount = trans_count; do { + struct expr *l, *r; + trans_count = 0; switch (e->type) { case E_OR: case E_AND: - e->left.expr = expr_eliminate_dups(e->left.expr); - e->right.expr = expr_eliminate_dups(e->right.expr); - expr_eliminate_dups1(e->type, &e->left.expr, &e->right.expr); + l = expr_eliminate_dups(e->left.expr); + r = expr_eliminate_dups(e->right.expr); + expr_eliminate_dups1(e->type, &l, &r); + e = expr_alloc_two(e->type, l, r); default: ; } @@ -668,8 +591,6 @@ struct expr *expr_eliminate_dups(struct expr *e) */ struct expr *expr_transform(struct expr *e) { - struct expr *tmp; - if (!e) return NULL; switch (e->type) { @@ -682,8 +603,9 @@ struct expr *expr_transform(struct expr *e) case E_SYMBOL: break; default: - e->left.expr = expr_transform(e->left.expr); - e->right.expr = expr_transform(e->right.expr); + e = expr_alloc_two(e->type, + expr_transform(e->left.expr), + expr_transform(e->right.expr)); } switch (e->type) { @@ -692,23 +614,18 @@ struct expr *expr_transform(struct expr *e) break; if (e->right.sym == &symbol_no) { // A=n -> !A - e->type = E_NOT; - e->left.expr = expr_alloc_symbol(e->left.sym); - e->right.sym = NULL; + e = expr_alloc_one(E_NOT, expr_alloc_symbol(e->left.sym)); break; } if (e->right.sym == &symbol_mod) { // A=m -> n 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; + e = expr_alloc_symbol(&symbol_no); break; } if (e->right.sym == &symbol_yes) { // A=y -> A - e->type = E_SYMBOL; - e->right.sym = NULL; + e = expr_alloc_symbol(e->left.sym); break; } break; @@ -717,23 +634,18 @@ struct expr *expr_transform(struct expr *e) break; if (e->right.sym == &symbol_no) { // A!=n -> A - e->type = E_SYMBOL; - e->right.sym = NULL; + e = expr_alloc_symbol(e->left.sym); break; } if (e->right.sym == &symbol_mod) { // A!=m -> y 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; + e = expr_alloc_symbol(&symbol_yes); break; } if (e->right.sym == &symbol_yes) { // A!=y -> !A - e->type = E_NOT; - e->left.expr = expr_alloc_symbol(e->left.sym); - e->right.sym = NULL; + e = expr_alloc_one(E_NOT, e->left.expr); break; } break; @@ -741,82 +653,51 @@ struct expr *expr_transform(struct expr *e) 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); + e = e->left.expr->left.expr; break; case E_EQUAL: case E_UNEQUAL: // !(A=B) -> A!=B - tmp = e->left.expr; - free(e); - e = tmp; - e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL; + e = expr_alloc_comp(e->left.expr->type == E_EQUAL ? E_UNEQUAL : E_EQUAL, + e->left.expr->left.sym, + e->left.expr->right.sym); break; case E_LEQ: case E_GEQ: // !(A<=B) -> A>B - tmp = e->left.expr; - free(e); - e = tmp; - e->type = e->type == E_LEQ ? E_GTH : E_LTH; + e = expr_alloc_comp(e->left.expr->type == E_LEQ ? E_GTH : E_LTH, + e->left.expr->left.sym, + e->left.expr->right.sym); break; case E_LTH: case E_GTH: // !(A A>=B - tmp = e->left.expr; - free(e); - e = tmp; - e->type = e->type == E_LTH ? E_GEQ : E_LEQ; + e = expr_alloc_comp(e->left.expr->type == E_LTH ? E_GEQ : E_LEQ, + e->left.expr->left.sym, + e->left.expr->right.sym); 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_alloc_and(expr_alloc_one(E_NOT, e->left.expr->left.expr), + expr_alloc_one(E_NOT, e->left.expr->right.expr)); 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_alloc_or(expr_alloc_one(E_NOT, e->left.expr->left.expr), + expr_alloc_one(E_NOT, e->left.expr->right.expr)); e = expr_transform(e); break; case E_SYMBOL: - if (e->left.expr->left.sym == &symbol_yes) { + 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) { + e = expr_alloc_symbol(&symbol_no); + else 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) { + e = expr_alloc_symbol(&symbol_mod); + else 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; - } + e = expr_alloc_symbol(&symbol_yes); break; default: ; @@ -940,18 +821,18 @@ struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symb case E_EQUAL: if (type == E_EQUAL) { if (sym == &symbol_yes) - return expr_copy(e); + return e; if (sym == &symbol_mod) return expr_alloc_symbol(&symbol_no); if (sym == &symbol_no) - return expr_alloc_one(E_NOT, expr_copy(e)); + return expr_alloc_one(E_NOT, e); } else { if (sym == &symbol_yes) - return expr_alloc_one(E_NOT, expr_copy(e)); + return expr_alloc_one(E_NOT, e); if (sym == &symbol_mod) return expr_alloc_symbol(&symbol_yes); if (sym == &symbol_no) - return expr_copy(e); + return e; } break; case E_SYMBOL: diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h index 4ab7422ddbd8..a398b2b2dbe0 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -29,11 +29,21 @@ enum expr_type { }; union expr_data { - struct expr *expr; - struct symbol *sym; + struct expr * const expr; + 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 hlist_node node; enum expr_type type; 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_and(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); bool expr_eq(struct expr *e1, struct expr *e2); tristate expr_calc_value(struct expr *e); diff --git a/scripts/kconfig/internal.h b/scripts/kconfig/internal.h index 02106eb7815e..84c2ea0389fd 100644 --- a/scripts/kconfig/internal.h +++ b/scripts/kconfig/internal.h @@ -11,6 +11,10 @@ extern HASHTABLE_DECLARE(sym_hashtable, SYMBOL_HASHSIZE); #define for_all_symbols(sym) \ hash_for_each(sym_hashtable, sym, node) +#define EXPR_HASHSIZE (1U << 14) + +extern HASHTABLE_DECLARE(expr_hashtable, EXPR_HASHSIZE); + struct menu; extern struct menu *current_menu, *current_entry; diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c index f61327fabead..4addd33749bb 100644 --- a/scripts/kconfig/menu.c +++ b/scripts/kconfig/menu.c @@ -107,12 +107,13 @@ static struct expr *rewrite_m(struct expr *e) switch (e->type) { case E_NOT: - e->left.expr = rewrite_m(e->left.expr); + e = expr_alloc_one(E_NOT, rewrite_m(e->left.expr)); break; case E_OR: case E_AND: - e->left.expr = rewrite_m(e->left.expr); - e->right.expr = rewrite_m(e->right.expr); + e = expr_alloc_two(e->type, + rewrite_m(e->left.expr), + rewrite_m(e->right.expr)); break; case E_SYMBOL: /* 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; while ((menu = menu->parent) != NULL) { - struct expr *dup_expr; if (!menu->visibility) 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, - dup_expr); + menu->visibility); } } @@ -322,7 +313,7 @@ static void _menu_finalize(struct menu *parent, bool inside_choice) */ basedep = rewrite_m(menu->dep); 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); menu->dep = basedep; @@ -366,7 +357,7 @@ static void _menu_finalize(struct menu *parent, bool inside_choice) */ dep = rewrite_m(prop->visible.expr); dep = expr_transform(dep); - dep = expr_alloc_and(expr_copy(basedep), dep); + dep = expr_alloc_and(basedep, dep); dep = expr_eliminate_dups(dep); prop->visible.expr = dep; @@ -377,11 +368,11 @@ static void _menu_finalize(struct menu *parent, bool inside_choice) if (prop->type == P_SELECT) { struct symbol *es = prop_get_symbol(prop); 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) { struct symbol *es = prop_get_symbol(prop); 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_eliminate_dups(expr_transform(dep)); - dep2 = expr_copy(basedep); + dep2 = basedep; expr_eliminate_eq(&dep, &dep2); - expr_free(dep); if (!expr_is_yes(dep2)) { /* Not superset, quit */ - expr_free(dep2); break; } /* Superset, put in submenu */ - expr_free(dep2); next: _menu_finalize(menu, false); menu->parent = parent; last_menu = menu; } - expr_free(basedep); if (last_menu) { parent->list = parent->next; parent->next = last_menu->next;