From a8558bc5a6db4f9b7f89edb73a019fd70cc9301f Mon Sep 17 00:00:00 2001 From: Akim Demaille Date: Sat, 30 Mar 2019 09:37:22 +0100 Subject: [PATCH] diagnostics: don't crash when declaring the error token as an nterm Reported by wcventure. http://lists.gnu.org/archive/html/bug-bison/2019-03/msg00008.html * src/symtab.c (complain_class_redeclared): Don't print empty locations. There can only be empty locations for predefined symbols. And the only symbol that is lexically available is the error token. So this appears to be the only possible way to have an error involving an empty location. * tests/input.at (Symbol class redefinition): Check it. --- src/symtab.c | 9 ++++++--- tests/input.at | 6 +++++- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/src/symtab.c b/src/symtab.c index 14c672b6..dd2a3d53 100644 --- a/src/symtab.c +++ b/src/symtab.c @@ -309,9 +309,12 @@ complain_class_redeclared (symbol *sym, symbol_class class, location second) class == token_sym ? _("symbol %s redeclared as a token") : _("symbol %s redeclared as a nonterminal"), sym->tag); - i += SUB_INDENT; - complain_indent (&sym->location, complaint, &i, - _("previous definition")); + if (!location_empty (sym->location)) + { + i += SUB_INDENT; + complain_indent (&sym->location, complaint, &i, + _("previous definition")); + } } diff --git a/tests/input.at b/tests/input.at index 312aa5a9..70c0cecc 100644 --- a/tests/input.at +++ b/tests/input.at @@ -625,6 +625,7 @@ AT_DATA([[input.y]], [[%token FOO %nterm FOO BAR %token BAR +%nterm error // The token error cannot be redefined as an nterm. %% FOO: BAR BAR: @@ -643,7 +644,10 @@ input.y:3.8-10: error: symbol BAR redeclared as a token input.y:2.12-14: previous definition %nterm FOO BAR ^~~ -input.y:5.1-3: error: rule given for FOO, which is a token +input.y:4.8-12: error: symbol error redeclared as a nonterminal + %nterm error // The token error cannot be redefined as an nterm. + ^~~~~ +input.y:6.1-3: error: rule given for FOO, which is a token FOO: BAR ^~~ ]])