diff options
Diffstat (limited to 'ovn/lib')
| -rw-r--r-- | ovn/lib/expr.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/ovn/lib/expr.c b/ovn/lib/expr.c index beb451e48..7289a9bc7 100644 --- a/ovn/lib/expr.c +++ b/ovn/lib/expr.c @@ -243,6 +243,11 @@ expr_fix_andor(struct expr *expr, bool short_circuit) } } +/* Returns 'expr' modified so that top-level oddities are fixed up: + * + * - Eliminates any EXPR_T_BOOLEAN operands at the top level. + * + * - Replaces one-operand EXPR_T_AND or EXPR_T_OR by its subexpression. */ static struct expr * expr_fix(struct expr *expr) { @@ -626,6 +631,7 @@ make_cmp(struct expr_context *ctx, if (f->symbol->level == EXPR_L_NOMINAL) { if (f->symbol->expansion) { + ovs_assert(f->symbol->width > 0); for (size_t i = 0; i < cs->n_values; i++) { const union mf_subvalue *value = &cs->values[i].value; bool positive = (value->integer & htonll(1)) != 0; @@ -1637,6 +1643,7 @@ compare_expr_sort(const void *a_, const void *b_) static struct expr *crush_cmps(struct expr *, const struct expr_symbol *); +/* Implementation of crush_cmps() for expr->type == EXPR_T_AND. */ static struct expr * crush_and(struct expr *expr, const struct expr_symbol *symbol) { @@ -1806,13 +1813,15 @@ compare_expr(const void *a_, const void *b_) return d; } +/* Implementation of crush_cmps() for expr->type == EXPR_T_OR. */ static struct expr * crush_or(struct expr *expr, const struct expr_symbol *symbol) { struct expr *sub, *next = NULL; /* First, crush all the subexpressions. That might eliminate the - * OR-expression entirely; if so, return the result. */ + * OR-expression entirely; if so, return the result. Otherwise, 'expr' + * is now a disjunction of cmps over the same symbol. */ LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { list_remove(&sub->node); expr_insert_andor(expr, next, crush_cmps(sub, symbol)); @@ -1822,7 +1831,7 @@ crush_or(struct expr *expr, const struct expr_symbol *symbol) return expr; } - /* Eliminate duplicates by sorting the subexpressions. */ + /* Sort subexpressions by value and mask, to bring together duplicates. */ size_t n = list_size(&expr->andor); struct expr **subs = xmalloc(n * sizeof *subs); @@ -1850,8 +1859,10 @@ crush_or(struct expr *expr, const struct expr_symbol *symbol) return expr_fix(expr); } -/* Converts 'expr', which must be a cmp in the sense determined by - * expr_is_cmp(). Returns a cmp, a disjunction of cmps, or a boolean. */ +/* Takes ownership of 'expr', which must be a cmp in the sense determined by + * 'expr_is_cmp(expr)', where 'symbol' is the symbol returned by that function. + * Returns an equivalent expression owned by the caller that is a single + * EXPR_T_CMP or a disjunction of them or a EXPR_T_BOOLEAN. */ static struct expr * crush_cmps(struct expr *expr, const struct expr_symbol *symbol) { |