Compile error: unknown type name 'yyscan_t'

[christopher-hopper]

I'm trying to compile and install jsonval and get this error repeated twice:

error: unknown type name ‘yyscan_t’

Complete output:

# make
bison json_parser.y
flex json_scanner.l
gcc -Wall main.c json_parser.tab.c json_scanner.yy.c -o jsonval
In file included from main.c:23:0:
json_parser.tab.h:65:14: error: unknown type name ‘yyscan_t’
 int yyparse (yyscan_t scanner);
              ^
In file included from json_parser.y:21:0:
json_parser.tab.h:65:14: error: unknown type name ‘yyscan_t’
 int yyparse (yyscan_t scanner);
              ^
json_scanner.yy.c:1295:16: warning: ‘input’ defined but not used [-Wunused-function]
     static int input  (yyscan_t yyscanner)
                ^
Makefile:4: recipe for target 'all' failed
make: *** [all] Error 1

Here's my environment details:

# flex --version
flex 2.6.0

# gcc --version
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.2) 5.4.0 20160609

# uname -a
Linux ThinkPad-Ubuntu 4.4.0-38-generic #57-Ubuntu SMP Tue Sep 6 15:42:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

Can you provide any guidance? Perhaps some documentation on compile requirements would help.

[christopher-hopper]

I read some posts describing a workaround for this issue. Apparently the bison parser doesn't know what yyscan_t is, so defining it to void can workaround this.

Here's a diff of a change I made to get the compile working:

diff --git a/json_parser.y b/json_parser.y
index 1f78ef4..9029a10 100644
--- a/json_parser.y
+++ b/json_parser.y
@@ -27,8 +27,8 @@ extern void yyerror(yyscan_t, const char *);
 %defines
 %error-verbose
 %pure-parser
-%parse-param {yyscan_t scanner}
-%lex-param {yyscan_t scanner}
+%parse-param {void *scanner}
+%lex-param {void *scanner}

 %token TSTRING
 %token TNUMBER

[naushada]

This circular dependency can also be fixed by adding below code in parser.y file
%code requires {
typedef void *yyscan_t;
}

[christopher-hopper]

@naushada
Can you supply a pull request with a working fix?

[naushada]

Please clone this https://github.com/naushada/jsonParser.git look at parser.y file Thanking You, Naushad

…

On Thu, Mar 7, 2019 at 9:43 AM Christopher Hopper ***@***.***> wrote: @naushada <https://github.com/naushada> Can you supply a pull request with a working fix? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#5 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ALp0D4zgv8LpxAnzaKA2b53jzVJXrymtks5vUJHPgaJpZM4KPb3Z> .

[naushada]

clone this link
https://github.com/naushada/jsonParser.git

Please look at parser.y file.