>Number:         23427
>Category:       bin
>Synopsis:       Flex C++ scanners no longer work with gcc 3
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Nov 13 23:32:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Audun Nordal
>Release:        1.6ZC i386
>Organization:
>Environment:
NetBSD vlab1 1.6ZC NetBSD 1.6ZC (GENERIC) #0: Tue Sep 30 01:15:20 UTC 2003  autobuild@tgm.netbsd.org:/autobuild/HEAD/i386/OBJ/autobuild/HEAD/src/sys/arch/i386/compile/GENERIC i386

>Description:
The flex scanner generator has drifted out of sync on current. There are a number of patches for various problems floating around, but the most serious problem is that the generated C++ scanners do not compile on gcc 3.x (apparently, it isn't C++ 98). I hereby request that at least the patches in e.g. Gentoo linux' sys-devel/flex package to be applied. I would have liked to point to a better location, but the flex directory seems to have been removed from ftp.gnu.org.

It looks like this also applies to pkgsrc/devel/flex
>How-To-Repeat:
To test the C++ problem, build the following scanner
<begin>
%%
%%
<end>
>Fix:
C++ fixes for gcc 3 from gentoo:
http://www.gentoo.org/cgi-bin/viewcvs.cgi/sys-devel/flex/files/flex-2.5.4a-gcc3.patch
http://www.gentoo.org/cgi-bin/viewcvs.cgi/sys-devel/flex/files/flex-2.5.4a-gcc31.patch

They apply more or less cleanly, below is my diff to current after patching

Index: FlexLexer.h
===================================================================
RCS file: /cvsroot/src/usr.bin/lex/FlexLexer.h,v
retrieving revision 1.8
diff -u -r1.8 FlexLexer.h
--- FlexLexer.h 1998/01/05 05:15:43     1.8
+++ FlexLexer.h 2003/11/13 23:26:40
@@ -43,7 +43,7 @@
 #ifndef __FLEX_LEXER_H
 // Never included before - need to define base class.
 #define __FLEX_LEXER_H
-#include <iostream.h>
+#include <iostream>

 extern "C++" {

@@ -60,14 +60,14 @@
        virtual void
                yy_switch_to_buffer( struct yy_buffer_state* new_buffer ) = 0;
        virtual struct yy_buffer_state*
-               yy_create_buffer( istream* s, int size ) = 0;
+               yy_create_buffer( std::istream* s, int size ) = 0;
        virtual void yy_delete_buffer( struct yy_buffer_state* b ) = 0;
-       virtual void yyrestart( istream* s ) = 0;
+       virtual void yyrestart( std::istream* s ) = 0;

        virtual int yylex() = 0;

        // Call yylex with new input/output sources.
-       int yylex( istream* new_in, ostream* new_out = 0 )
+       int yylex( std::istream* new_in, std::ostream* new_out = 0 )
                {
                switch_streams( new_in, new_out );
                return yylex();
@@ -75,8 +75,8 @@

        // Switch to new input/output streams.  A nil stream pointer
        // indicates "keep the current one".
-       virtual void switch_streams( istream* new_in = 0,
-                                       ostream* new_out = 0 ) = 0;
+       virtual void switch_streams( std::istream* new_in = 0,
+                                    std::ostream* new_out = 0 ) = 0;

        int lineno() const              { return yylineno; }

@@ -103,17 +103,17 @@
 public:
        // arg_yyin and arg_yyout default to the cin and cout, but we
        // only make that assignment when initializing in yylex().
-       yyFlexLexer( istream* arg_yyin = 0, ostream* arg_yyout = 0 );
+       yyFlexLexer( std::istream* arg_yyin = 0, std::ostream* arg_yyout = 0 );

        virtual ~yyFlexLexer();

        void yy_switch_to_buffer( struct yy_buffer_state* new_buffer );
-       struct yy_buffer_state* yy_create_buffer( istream* s, int size );
+       struct yy_buffer_state* yy_create_buffer( std::istream* s, int size );
        void yy_delete_buffer( struct yy_buffer_state* b );
-       void yyrestart( istream* s );
+       void yyrestart( std::istream* s );

        virtual int yylex();
-       virtual void switch_streams( istream* new_in, ostream* new_out );
+       virtual void switch_streams( std::istream* new_in, std::ostream* new_out
 );

 protected:
        virtual int LexerInput( char* buf, int max_size );
@@ -124,7 +124,7 @@
        int yyinput();

        void yy_load_buffer_state();
-       void yy_init_buffer( struct yy_buffer_state* b, istream* s );
+       void yy_init_buffer( struct yy_buffer_state* b, std::istream* s );
        void yy_flush_buffer( struct yy_buffer_state* b );

        int yy_start_stack_ptr;
@@ -139,8 +139,8 @@
        yy_state_type yy_try_NUL_trans( yy_state_type current_state );
        int yy_get_next_buffer();

-       istream* yyin;  // input source for default LexerInput
-       ostream* yyout; // output sink for default LexerOutput
+       std::istream* yyin;     // input source for default LexerInput
+       std::ostream* yyout;    // output sink for default LexerOutput

        struct yy_buffer_state* yy_current_buffer;

Index: flex.skl
===================================================================
RCS file: /cvsroot/src/usr.bin/lex/flex.skl,v
retrieving revision 1.16
diff -u -r1.16 flex.skl
--- flex.skl    2001/01/06 02:09:31     1.16
+++ flex.skl    2003/11/13 23:26:40
@@ -25,7 +25,8 @@

 #include <stdlib.h>
 %+
-class istream;
+#include <iostream>
+using namespace std;
 %*
 #include <unistd.h>


>Release-Note:
>Audit-Trail:
>Unformatted: