The special error value YYerror is only available since bison 3.6
(released 2020). For example the version used by oss-fuzz does not
support it.
Use a special token in case YYerror is not available. Only downside is
a duplicate error message, one from the manual yyerror() call and one
from within bison for the unexpected special token (which would be
omitted by using YYerror).
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
checkpolicy/policy_parse.y | 1 +
checkpolicy/policy_scan.l | 9 ++++++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/checkpolicy/policy_parse.y b/checkpolicy/policy_parse.y
index e0103502..1b275ebc 100644
--- a/checkpolicy/policy_parse.y
+++ b/checkpolicy/policy_parse.y
@@ -153,6 +153,7 @@ typedef int (* require_func_t)(int pass);
%token FILESYSTEM
%token DEFAULT_USER DEFAULT_ROLE DEFAULT_TYPE DEFAULT_RANGE
%token LOW_HIGH LOW HIGH GLBLUB
+%token INVALID_CHAR
%left OR
%left XOR
diff --git a/checkpolicy/policy_scan.l b/checkpolicy/policy_scan.l
index 1926129c..c4d8e937 100644
--- a/checkpolicy/policy_scan.l
+++ b/checkpolicy/policy_scan.l
@@ -308,7 +308,14 @@ GLBLUB { return(GLBLUB); }
"]" |
"~" |
"*" { return(yytext[0]); }
-. { yyerror("unrecognized character"); return YYerror; }
+. { yyerror("unrecognized character");
+/* Available since bison 3.6, avoids duplicate error message */
+#ifdef YYerror
+ return YYerror;
+#else
+ return INVALID_CHAR;
+#endif
+ }
%%
int yyerror(const char *msg)
{
--
2.43.0
