warnings: raise warning for useless printers or destructors

* src/scan-code.h (code_props): Add field 'is_used'.
(CODE_PROPS_NONE_INIT): Adjust.
* src/scan-code.l (code_props_plain_init, code_props_symbol_action_init)
(code_props_rule_action_init): Instead of implementing several
times the initialization of the code_props structures,
use code_props_none_init.
* src/symtab.c (symbol_check_defined): If a symbol does not have a
destructor (resp. printer) but has a type which has a destructor (resp.
printer), then set field 'is_used' to true.
(semantic_type_check_defined): If a type has a destructor (resp. printer)
but all symbols of this type have already a destructor (resp. printer),
then raise a warning.
* tests/input.at (Useless printers or destructors): New.

Signed-off-by: Akim Demaille <akim@lrde.epita.fr>
This commit is contained in:
Victor Santet
2012-06-14 14:20:07 +02:00
committed by Akim Demaille
parent 9641b918ba
commit ea9a35c605
5 changed files with 96 additions and 10 deletions

14
NEWS
View File

@@ -31,6 +31,20 @@ GNU Bison NEWS
This is now only a warning.
** Warnings about useless destructors or printers
Bison now warns about useless destructors or printers. In the following
example, the printer for <type1>, and the destructor for <type2> are
useless: all symbols of <type1> (token1) already have a printer, and all
symbols of type <type2> (token2) already have a destructor.
%token <type1> token1
<type2> token2
<type3> token3
<type4> token4
%printer {} token1 <type1> <type3>
%destructor {} token2 <type2> <type4>
** Additional yylex/yyparse arguments
The new directive %param declares additional arguments to both yylex and