diff options
Diffstat (limited to 'filter/config.Y')
| -rw-r--r-- | filter/config.Y | 59 |
1 files changed, 52 insertions, 7 deletions
diff --git a/filter/config.Y b/filter/config.Y index b67ca925..f8f47862 100644 --- a/filter/config.Y +++ b/filter/config.Y @@ -22,6 +22,36 @@ static inline u32 pair_b(u32 p) { return p & 0xFFFF; } #define f_generate_complex(fi_code, da, arg) \ f_new_inst(FI_EA_SET, f_new_inst(fi_code, f_new_inst(FI_EA_GET, da), arg), da) +static int +f_new_var(struct sym_scope *s) +{ + /* + * - A variable is an offset on vstack from vbase. + * - Vbase is set on filter start / function call. + * - Scopes contain anonymous scopes (blocks) inside filter/function scope + * - Each scope knows number of vars in that scope + * - Offset is therefore a sum of 'slots' up to named scope + * - New variables are added on top of vstk, so intermediate values cannot + * be there during FI_VAR_INIT. I.e. no 'var' inside 'term'. + * - Also, each f_line must always have its scope, otherwise a variable may + * be defined but not initialized if relevant f_line is not executed. + */ + + int offset = s->slots++; + + while (!s->name) + { + s = s->next; + ASSERT(s); + offset += s->slots; + } + + if (offset >= 0xff) + cf_error("Too many variables, at most 255 allowed"); + + return offset; +} + /* * Sets and their items are during parsing handled as lists, linked * through left ptr. The first item in a list also contains a pointer @@ -296,7 +326,7 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN, %nonassoc ELSE %type <xp> cmds_int cmd_prep -%type <x> term cmd cmds constant constructor print_list var_list function_call symbol_value bgp_path_expr bgp_path bgp_path_tail +%type <x> term cmd cmd_var cmds cmds_scoped constant constructor print_list var var_init var_list function_call symbol_value bgp_path_expr bgp_path bgp_path_tail %type <fda> dynamic_attr %type <fsa> static_attr %type <f> filter where_filter @@ -425,7 +455,7 @@ function_args: function_vars: /* EMPTY */ { $$ = 0; } | function_vars type symbol ';' { - cf_define_symbol($3, SYM_VARIABLE | $2, offset, sym_->scope->slots++); + cf_define_symbol($3, SYM_VARIABLE | $2, offset, f_new_var(sym_->scope)); $$ = $1 + 1; } ; @@ -492,7 +522,11 @@ cmds: /* EMPTY */ { $$ = NULL; } | cmds_int { $$ = $1.begin; } ; -cmd_prep: cmd { +cmds_scoped: { cf_push_soft_scope(); } cmds { cf_pop_soft_scope(); $$ = $2; } ; + +cmd_var: var | cmd ; + +cmd_prep: cmd_var { $$.begin = $$.end = $1; if ($1) while ($$.end->next) @@ -639,7 +673,7 @@ fprefix_set: ; switch_body: /* EMPTY */ { $$ = NULL; } - | switch_body switch_items ':' cmds { + | switch_body switch_items ':' cmds_scoped { /* Fill data fields */ struct f_tree *t; struct f_line *line = f_linearize($4, 0); @@ -647,7 +681,7 @@ switch_body: /* EMPTY */ { $$ = NULL; } t->data = line; $$ = f_merge_items($1, $2); } - | switch_body ELSECOL cmds { + | switch_body ELSECOL cmds_scoped { struct f_tree *t = f_new_tree(); t->from.type = t->to.type = T_VOID; t->right = t; @@ -854,8 +888,19 @@ print_list: /* EMPTY */ { $$ = NULL; } } ; +var_init: + /* empty */ { $$ = f_new_inst(FI_CONSTANT, (struct f_val) { }); } + | '=' term { $$ = $2; } + ; + +var: + type symbol var_init ';' { + struct symbol *sym = cf_define_symbol($2, SYM_VARIABLE | $1, offset, f_new_var(sym_->scope)); + $$ = f_new_inst(FI_VAR_INIT, $3, sym); + } + cmd: - '{' cmds '}' { + '{' cmds_scoped '}' { $$ = $2; } | IF term THEN cmd { @@ -912,7 +957,7 @@ cmd: | PRINTN print_list ';' { $$ = f_new_inst(FI_PRINT, $2); } - | function_call ';' { $$ = f_new_inst(FI_DROP_RESULT, $1); } + | function_call ';' { $$ = f_new_inst(FI_DROP_RESULT, $1); } | CASE term '{' switch_body '}' { $$ = f_new_inst(FI_SWITCH, $2, build_tree($4)); } |