'yylval was not declared' on switch from Bison 2.4.1 to 3.0.2

[Evan Lavelle]

Any idea how to fix this? I have a grammar which compiled without 
problems on bison 2.4.1/gcc 4.4.7 (RHEL 6.5), but which won't now 
compile on bison 3.0.2/gcc 4.8.2 (Ubuntu 14.04).

The bison.tab.cc output from 2.4.1 included a definition of yylval as:

semantic_type yylval;

The 3.0.2 output has no definition, and the compiler complains when it 
reaches the first reference to yylval in the new bison.tab.cc, saying 
that "'yylval' was not declared in this scope." This corresponds to my 
first use of 'yylval' in my .y file.

I'm using the C++ skeleton (lalr1.cc), and not explicitly declaring a 
pure-parser.

http://stackoverflow.com/questions/23685843/problems-with-yylval-and-yylloc-after-switching-to-bison-3-0 
is the same question on stackoverflow, from May 15th, with a suggestion 
to use yyla.value instead.

Thanks.