c - Using union in yacc file -

i'm trying develop basic compiler , i'm using union yylval follows:

%{ #include <string.h> #include <stdio.h> struct info {   int line;   /* details unimportant */ }; %}  %union{   char *str;   struct info *ptr;             } 

in lexer definition, have

%{ #include "parse.tab.h" %} 

but when compile generated lexer, following errors:

y.tab.h:  unknown type name 'yystype'. error: request member str in not structure or union. 

do need #define yystype well?

(i edited original question insert enough information source files make question answerable. mistakes in transcription fault , apologize -- rici.)

no. if use %union declaration, must not #define yystype; bison manual makes clear.

however, necessary declarations -- in case, declaration of struct info -- must included in lexer description file (parse.l) well. 2 generated files independent of each other, fact struct info declared in parser not make definition automatically available lexer.

in order avoid repeating declarations, idea put them in separate header file:

file: info.h (added)

#ifndef info_h_header_ #define info_h_header_ struct info {   int line;   /* details unimportant */ }; // ... #endif 

file: parse.y (now #include's info.h instead of in-line struct declaration)

%{ #include <stdio.h> #include <string.h> #include "info.h" %} %union{   char *str;   struct info *ptr; } 

file: parse.l (also #includes info.h)

%{ #include <stdio.h> #include <string.h> /* must come *before* including parse.tab.h */ #include "info.h" #include "parse.tab.h" %}