diagnostics: yacc reserves %type to nonterminals

On

    %token TOKEN1
    %type  <ival> TOKEN1 TOKEN2 't'
    %token TOKEN2
    %%
    expr:

bison -Wyacc gives

    input.y:2.15-20: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
        2 | %type  <ival> TOKEN1 TOKEN2 't'
          |               ^~~~~~
    input.y:2.29-31: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
        2 | %type  <ival> TOKEN1 TOKEN2 't'
          |                             ^~~
    input.y:2.22-27: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
        2 | %type  <ival> TOKEN1 TOKEN2 't'
          |                      ^~~~~~

The messages appear to be out of order, but they are emitted when the
error is found.

* src/symtab.h (symbol_class): Add pct_type_sym, used to denote
symbols appearing in %type.
* src/symtab.c (complain_pct_type_on_token): New.
(symbol_class_set): Check that %type is not applied to tokens.
(symbol_check_defined): pct_type_sym also means undefined.
* src/parse-gram.y (symbol_decl.1): Set the class to pct_type_sym.
* src/reader.c (grammar_current_rule_begin): pct_type_sym also means
undefined.
* tests/input.at (Yacc's %type): New.
This commit is contained in:
Akim Demaille
2019-11-16 17:26:51 +01:00
parent 1817b475a6
commit 28d1ca8f48
7 changed files with 141 additions and 28 deletions

24
NEWS
View File

@@ -2,6 +2,30 @@ GNU Bison NEWS
* Noteworthy changes in release ?.? (????-??-??) [?]
** New Features
*** Better POSIX Yacc compatibility diagnostics
POSIX Yacc restricts %type to nonterminals. This is now diagnosed by
-Wyacc.
%token TOKEN1
%type <ival> TOKEN1 TOKEN2 't'
%token TOKEN2
%%
expr:
gives, with -Wyacc
input.y:2.15-20: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
2 | %type <ival> TOKEN1 TOKEN2 't'
| ^~~~~~
input.y:2.29-31: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
2 | %type <ival> TOKEN1 TOKEN2 't'
| ^~~
input.y:2.22-27: warning: POSIX yacc reserves %type to nonterminals [-Wyacc]
2 | %type <ival> TOKEN1 TOKEN2 't'
| ^~~~~~
* Noteworthy changes in release 3.4.90 (2019-10-29) [beta]