diff options
Diffstat (limited to 'ovn')
| -rw-r--r-- | ovn/lib/expr.c | 75 |
1 files changed, 65 insertions, 10 deletions
diff --git a/ovn/lib/expr.c b/ovn/lib/expr.c index 5840ef871..148ac869e 100644 --- a/ovn/lib/expr.c +++ b/ovn/lib/expr.c @@ -1658,8 +1658,8 @@ struct annotation_nesting { const struct expr_symbol *symbol; }; -struct expr *expr_annotate__(struct expr *, const struct shash *symtab, - struct ovs_list *nesting, char **errorp); +static struct expr *expr_annotate_(struct expr *, const struct shash *symtab, + struct ovs_list *nesting, char **errorp); static struct expr * parse_and_annotate(const char *s, const struct shash *symtab, @@ -1670,7 +1670,7 @@ parse_and_annotate(const char *s, const struct shash *symtab, expr = expr_parse_string(s, symtab, NULL, NULL, &error); if (expr) { - expr = expr_annotate__(expr, symtab, nesting, &error); + expr = expr_annotate_(expr, symtab, nesting, &error); } if (expr) { *errorp = NULL; @@ -1685,7 +1685,7 @@ parse_and_annotate(const char *s, const struct shash *symtab, static struct expr * expr_annotate_cmp(struct expr *expr, const struct shash *symtab, - struct ovs_list *nesting, char **errorp) + bool append_prereqs, struct ovs_list *nesting, char **errorp) { const struct expr_symbol *symbol = expr->cmp.symbol; const struct annotation_nesting *iter; @@ -1703,7 +1703,7 @@ expr_annotate_cmp(struct expr *expr, const struct shash *symtab, ovs_list_push_back(nesting, &an.node); struct expr *prereqs = NULL; - if (symbol->prereqs) { + if (append_prereqs && symbol->prereqs) { prereqs = parse_and_annotate(symbol->prereqs, symtab, nesting, errorp); if (!prereqs) { goto error; @@ -1744,21 +1744,65 @@ error: return NULL; } -struct expr * +/* Append (logical AND) prerequisites for given symbol to the expression. */ +static struct expr * +expr_append_prereqs(struct expr *expr, const struct expr_symbol *symbol, + const struct shash *symtab, struct ovs_list *nesting, + char **errorp) +{ + struct expr *prereqs = NULL; + + if (symbol->prereqs) { + prereqs = parse_and_annotate(symbol->prereqs, symtab, nesting, errorp); + if (!prereqs) { + expr_destroy(expr); + return NULL; + } + } + + return prereqs ? expr_combine(EXPR_T_AND, expr, prereqs) : expr; +} + +static const struct expr_symbol *expr_get_unique_symbol( + const struct expr *expr); + +/* Ordinarily, annotation adds prerequisites to the expression, and that's what + * this function does if 'append_prereqs' is true. If 'append_prereqs' is + * false, this function ignores prerequisites (in which case the caller must + * have arranged to deal with them). */ +static struct expr * expr_annotate__(struct expr *expr, const struct shash *symtab, - struct ovs_list *nesting, char **errorp) + bool append_prereqs, struct ovs_list *nesting, char **errorp) { switch (expr->type) { case EXPR_T_CMP: - return expr_annotate_cmp(expr, symtab, nesting, errorp); + return expr_annotate_cmp(expr, symtab, append_prereqs, nesting, + errorp); case EXPR_T_AND: case EXPR_T_OR: { struct expr *sub, *next; + /* Detect whether every term in 'expr' mentions the same symbol. If + * so, then suppress prerequisites for that symbol for those terms and + * instead apply them once at our higher level. + * + * If 'append_prereqs' is false, though, we're not supposed to handle + * prereqs at all (because our caller is already doing it). */ + if (append_prereqs) { + const struct expr_symbol *sym = expr_get_unique_symbol(expr); + if (sym) { + append_prereqs = false; + expr = expr_append_prereqs(expr, sym, symtab, nesting, errorp); + if (!expr) { + return NULL; + } + } + } + LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { ovs_list_remove(&sub->node); - struct expr *new_sub = expr_annotate__(sub, symtab, + struct expr *new_sub = expr_annotate__(sub, symtab, append_prereqs, nesting, errorp); if (!new_sub) { expr_destroy(expr); @@ -1780,6 +1824,17 @@ expr_annotate__(struct expr *expr, const struct shash *symtab, } } +/* Same interface and purpose as expr_annotate(), with an additional parameter + * for internal bookkeeping. + * + * Uses 'nesting' to ensure that a given symbol is not recursively expanded. */ +static struct expr * +expr_annotate_(struct expr *expr, const struct shash *symtab, + struct ovs_list *nesting, char **errorp) +{ + return expr_annotate__(expr, symtab, true, nesting, errorp); +} + /* "Annotates" 'expr', which does the following: * * - Applies prerequisites, by locating each comparison operator whose @@ -1802,7 +1857,7 @@ struct expr * expr_annotate(struct expr *expr, const struct shash *symtab, char **errorp) { struct ovs_list nesting = OVS_LIST_INITIALIZER(&nesting); - return expr_annotate__(expr, symtab, &nesting, errorp); + return expr_annotate_(expr, symtab, &nesting, errorp); } static struct expr * |