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mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-11-17 16:48:43 +00:00

Filter: Fix bug in variable shadowing

When a new variable used the same name as an existing symbol in an outer
scope, then offset number was defined based on a scope of the existing
symbol ($3) instead of a scope of the new symbol (sym_). That can lead
to two variables sharing the same memory slot.
This commit is contained in:
Ondrej Zajicek (work) 2022-03-06 22:57:33 +01:00 committed by Ondrej Zajicek
parent 946cedfcfe
commit 1e6acf34bb

View File

@ -408,7 +408,7 @@ function_argsn:
| function_argsn type symbol ';' { | function_argsn type symbol ';' {
if ($3->scope->slots >= 0xfe) cf_error("Too many declarations, at most 255 allowed"); if ($3->scope->slots >= 0xfe) cf_error("Too many declarations, at most 255 allowed");
$$ = cfg_alloc(sizeof(struct f_arg)); $$ = cfg_alloc(sizeof(struct f_arg));
$$->arg = cf_define_symbol($3, SYM_VARIABLE | $2, offset, $3->scope->slots++); $$->arg = cf_define_symbol($3, SYM_VARIABLE | $2, offset, sym_->scope->slots++);
$$->next = $1; $$->next = $1;
} }
; ;
@ -417,7 +417,7 @@ function_args:
'(' ')' { $$ = NULL; } '(' ')' { $$ = NULL; }
| '(' function_argsn type symbol ')' { | '(' function_argsn type symbol ')' {
$$ = cfg_alloc(sizeof(struct f_arg)); $$ = cfg_alloc(sizeof(struct f_arg));
$$->arg = cf_define_symbol($4, SYM_VARIABLE | $3, offset, $4->scope->slots++); $$->arg = cf_define_symbol($4, SYM_VARIABLE | $3, offset, sym_->scope->slots++);
$$->next = $2; $$->next = $2;
} }
; ;
@ -425,7 +425,7 @@ function_args:
function_vars: function_vars:
/* EMPTY */ { $$ = 0; } /* EMPTY */ { $$ = 0; }
| function_vars type symbol ';' { | function_vars type symbol ';' {
cf_define_symbol($3, SYM_VARIABLE | $2, offset, $3->scope->slots++); cf_define_symbol($3, SYM_VARIABLE | $2, offset, sym_->scope->slots++);
$$ = $1 + 1; $$ = $1 + 1;
} }
; ;