diff options
author | Patrick McHardy <kaber@trash.net> | 2009-03-20 08:12:18 +0100 |
---|---|---|
committer | Patrick McHardy <kaber@trash.net> | 2009-03-20 08:12:18 +0100 |
commit | 5c40780440c0e8661fc7cfcec72dab48b934631d (patch) | |
tree | c6f334da0a6a2bc2fca4e48497408f477fb80fa9 /src | |
parent | 2ae0ab5fb3eabc149bad1250c681a7a5f2aea694 (diff) |
Add support for scoping and symbol binding
As a first step towards stand-alone sets, add support for scoping and
binding symbols. This will be used for user-defined constants, as well
as declarations of modifiable (stand-alone) sets once the kernel side
is ready.
Scopes are currently limited to three nesting levels: the global scope,
table block scopes and chain block scopes.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'src')
-rw-r--r-- | src/parser.y | 32 | ||||
-rw-r--r-- | src/rule.c | 32 |
2 files changed, 62 insertions, 2 deletions
diff --git a/src/parser.y b/src/parser.y index b13e932e..1ca5981b 100644 --- a/src/parser.y +++ b/src/parser.y @@ -33,6 +33,7 @@ void parser_init(struct parser_state *state, struct list_head *msgs) memset(state, 0, sizeof(*state)); init_list_head(&state->cmds); state->msgs = msgs; + state->scopes[0] = scope_init(&state->top_scope, NULL); } static void yyerror(struct location *loc, void *scanner, @@ -41,6 +42,22 @@ static void yyerror(struct location *loc, void *scanner, erec_queue(error(loc, "%s", s), state->msgs); } +static struct scope *current_scope(const struct parser_state *state) +{ + return state->scopes[state->scope]; +} + +static void open_scope(struct parser_state *state, struct scope *scope) +{ + scope_init(scope, current_scope(state)); + state->scopes[++state->scope] = scope; +} + +static void close_scope(struct parser_state *state) +{ + state->scope--; +} + static void location_init(void *scanner, struct parser_state *state, struct location *loc) { @@ -474,6 +491,7 @@ add_cmd : TABLE table_spec '{' table_block '}' { handle_merge(&$3->handle, &$2); + close_scope(state); $$ = cmd_alloc(CMD_ADD, CMD_OBJ_TABLE, &$2, $5); } | CHAIN chain_spec @@ -484,6 +502,7 @@ add_cmd : TABLE table_spec '{' chain_block '}' { handle_merge(&$3->handle, &$2); + close_scope(state); $$ = cmd_alloc(CMD_ADD, CMD_OBJ_CHAIN, &$2, $5); } | RULE ruleid_spec rule @@ -530,7 +549,11 @@ flush_cmd : TABLE table_spec } ; -table_block_alloc : /* empty */ { $$ = table_alloc(); } +table_block_alloc : /* empty */ + { + $$ = table_alloc(); + open_scope(state, &$$->scope); + } ; table_block : /* empty */ { $$ = $<table>-1; } @@ -547,11 +570,16 @@ table_line : CHAIN chain_identifier chain_block_alloc '{' chain_block '}' { handle_merge(&$3->handle, &$2); + close_scope(state); $$ = $3; } ; -chain_block_alloc : /* empty */ { $$ = chain_alloc(NULL); } +chain_block_alloc : /* empty */ + { + $$ = chain_alloc(NULL); + open_scope(state, &$$->scope); + } ; chain_block : /* empty */ { $$ = $<chain>-1; } @@ -68,6 +68,38 @@ void rule_print(const struct rule *rule) printf("\n"); } +struct scope *scope_init(struct scope *scope, const struct scope *parent) +{ + scope->parent = parent; + init_list_head(&scope->symbols); + return scope; +} + +void symbol_bind(struct scope *scope, const char *identifier, struct expr *expr) +{ + struct symbol *sym; + + sym = xzalloc(sizeof(*sym)); + sym->identifier = xstrdup(identifier); + sym->expr = expr; + + list_add_tail(&sym->list, &scope->symbols); +} + +struct symbol *symbol_lookup(const struct scope *scope, const char *identifier) +{ + struct symbol *sym; + + while (scope != NULL) { + list_for_each_entry(sym, &scope->symbols, list) { + if (!strcmp(sym->identifier, identifier)) + return sym; + } + scope = scope->parent; + } + return NULL; +} + struct chain *chain_alloc(const char *name) { struct chain *chain; |