diff options
author | Joel E. Denny <jdenny@clemson.edu> | 2009-12-30 03:20:11 -0500 |
---|---|---|
committer | Joel E. Denny <jdenny@clemson.edu> | 2009-12-31 12:49:42 -0500 |
commit | f1ceed07743630aa2aef7c77d8bde23c3794ee1b (patch) | |
tree | 17b619704159b05a21771eeb11c7195b9c813d0f | |
parent | d2829fdc040f928cc3596725783183f9af8ca5af (diff) | |
download | bison-f1ceed07743630aa2aef7c77d8bde23c3794ee1b.tar.gz |
POSIX: warn if %prec's token was not defined.
Reported by Florian Krohm at
<http://lists.gnu.org/archive/html/bug-bison/2009-12/msg00005.html>.
* NEWS (2.4.2): Document.
* src/reader.c (grammar_rule_check): Implement.
(grammar_current_rule_prec_set): Add comments explaining that we
here assume a %prec identifier is a token, but we still manage
to support POSIX.
* tests/input.at (%prec's token must be defined): New test
group.
-rw-r--r-- | ChangeLog | 13 | ||||
-rw-r--r-- | NEWS | 10 | ||||
-rw-r--r-- | src/reader.c | 19 | ||||
-rw-r--r-- | tests/input.at | 20 |
4 files changed, 62 insertions, 0 deletions
@@ -1,3 +1,16 @@ +2009-12-30 Joel E. Denny <jdenny@clemson.edu> + + POSIX: warn if %prec's token was not defined. + Reported by Florian Krohm at + <http://lists.gnu.org/archive/html/bug-bison/2009-12/msg00005.html>. + * NEWS (2.4.2): Document. + * src/reader.c (grammar_rule_check): Implement. + (grammar_current_rule_prec_set): Add comments explaining that we + here assume a %prec identifier is a token, but we still manage + to support POSIX. + * tests/input.at (%prec's token must be defined): New test + group. + 2009-12-31 Joel E. Denny <jdenny@clemson.edu> * HACKING (Release Procedure): Recommend a secure automake. @@ -3,6 +3,16 @@ Bison News * Changes in version 2.4.2 (????-??-??): +** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately. + + POSIX specifies that an error be reported for any identifier that does + not appear on the LHS of a grammar rule and that is not defined by + %token, %left, %right, or %nonassoc. Bison 2.3b and later lost this + error report for the case when an identifier appears only after a + %prec directive. It is now restored. However, for backward + compatibility with recent Bison releases, it is only a warning for + now. In Bison 2.5 and later, it will return to being an error. + ** Detection of GNU M4 1.4.6 or newer during configure is improved. ** Warnings from gcc's -Wundef option about undefined YYENABLE_NLS, diff --git a/src/reader.c b/src/reader.c index 74d7dca4..38191ee6 100644 --- a/src/reader.c +++ b/src/reader.c @@ -292,6 +292,15 @@ grammar_rule_check (const symbol_list *r) warn_at (r->location, _("unset value: $$")); } } + + /* See comments in grammar_current_rule_prec_set for how POSIX + mandates this complaint. It's only for identifiers, so skip + it for char literals and strings, which are always tokens. */ + if (r->ruleprec + && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"' + && !r->ruleprec->declared && !r->ruleprec->prec) + warn_at (r->location, _("token for %%prec is not defined: %s"), + r->ruleprec->tag); } @@ -364,6 +373,16 @@ grammar_midrule_action (void) void grammar_current_rule_prec_set (symbol *precsym, location loc) { + /* POSIX says that any identifier is a nonterminal if it does not + appear on the LHS of a grammar rule and is not defined by %token + or by one of the directives that assigns precedence to a token. We + ignore this here because the only kind of identifier that POSIX + allows to follow a %prec is a token and because assuming it's a + token now can produce more logical error messages. Nevertheless, + grammar_rule_check does obey what we believe is the real intent of + POSIX here: that an error be reported for any identifier that + appears after %prec but that is not defined separately as a + token. */ symbol_class_set (precsym, token_sym, loc, false); if (current_rule->ruleprec) complain_at (loc, _("only one %s allowed per rule"), "%prec"); diff --git a/tests/input.at b/tests/input.at index be84f9cf..5cec25b9 100644 --- a/tests/input.at +++ b/tests/input.at @@ -702,6 +702,26 @@ AT_BISON_CHECK([input.y], [1], [], AT_CLEANUP +## ------------------------------- ## +## %prec's token must be defined. ## +## ------------------------------- ## + +AT_SETUP([[%prec's token must be defined]]) + +# According to POSIX, a %prec token must be defined separately. + +AT_DATA([[input.y]], +[[%% +start: %prec PREC ; +]]) + +AT_BISON_CHECK([[input.y]], [[0]], [], +[[input.y:2.8-17: warning: token for %prec is not defined: PREC +]]) + +AT_CLEANUP + + ## -------------------------------- ## ## Reject unused %code qualifiers. ## ## -------------------------------- ## |