lynx-dev removing strings used in CTRACE when configured without tracing

[Vlad Harchev]

 The are several approaches:
1)Use a feature of gcc - macros with variable number of arguments, in this
  case we can do the following

#ifndef DEBUG
# define CTRACE(f, args...) /*nothing*/
#else 
...

I don't know whether cccp - a c preprocessor distributed with GCC can do that,
but gcc supports it.

2)  First I've written the following script
_____________
# copyright 1999 by Vlad Harchev <address@hidden>. Distributed under GPL.
#args - the file names to process

#this will match C string that doesn't wrap lines
CSTR='\("\([^"]*\(\\"\)*\)*"\)';
CTRACE='\(CTRACE[ \t]*([ \t]*[A-z_][_A-z0-9]*[ \t]*,[ \t]*\)';

tmpnm="_tmp$$";
for i; do
    echo converting $i
    mv $i $tmpnm &&    
    sed -e 's/'"$CTRACE"'\(\('"$CSTR"'[ \t]*\)*\)\([,)]\)/\1CT_(\2)\7/g' \
            $tmpnm > $i &&  rm $tmpnm;
done;    
____________

 It includes the string used as format specifier in the parentheses preceded
by CT_ (assumming that we'l define macro CT_(x) ). So, the following line 
 CTRACE( f, "text" "text \"more", params);
will be substituted with 
 CTRACE( f, CT_("text" "text \"more"), params);
But I found this inacceptable, since when the string constant is long enough,
the sed processes each string VERY slow. 
 The file I processed with sed was of the form (file had only 1 line):
  CTRACE( f, "123456789_123456789" );
 It takes 37 seconds for sed to substitute this line (correctly tho'). I have
5x86-133, 32MB of RAM (and no cpu-hungry jobs). Seems that sed I'm using is 
broken - it's GNU sed-3.02 (was supplied with my RedHat 5.2). Probably it's a
bug in regexp code.
 For shorter lines, like 
  CTRACE( f, "123456789_123456" );
 it takes 5 seconds (the string is 3 chars shorter as you see).

BTW, can you test the script with other seds (probaly with GNU sed 2.x)

3) So I wrote the the small program using lex (it does the same as script
above, but very fast).
--------------ctrace-wrap.l-----
/* copyright 1999 by Vlad Harchev <address@hidden>. Distributed under GPL.*/
%x SEENCTRACE
%option noyywrap

%{
#include <stdio.h>
%}

W ([ \t\n]*)
CSTR (\"([^"\\]*(\\\")*)*\")
%%

CTRACE{W}\({W}[A-z_][A-z_0-9]*{W},{W} { fwrite(yytext,yyleng,1,stdout);
        BEGIN(SEENCTRACE); }
        
<SEENCTRACE>({CSTR}{W})* { fwrite("CT_(",4,1,stdout); 
    fwrite(yytext,yyleng,1,stdout); fwrite(")",1,1,stdout); BEGIN(0); }    

%%

void main()
{
  yylex();
};
----------------------------
 It should be called by a script that will process all files passed.
So, to remove all string literals from lynx binary when lynx configured with 
--disable-trace, the following strings should be added to HTUtils.h:

#ifndef DEBUG
# define CT_(x) NULL
#else
# define CT_(x) x
#endif

So the new rule for using CTRACE macro:
*wrap the format specifier string in CT_(), eg instead of
 CTRACE( tfp, "foo" );
use 
 CTRACE( tfp, CT_("foo") );

 More ideas: may be it will be useful to define CT_  the following way
#ifndef DEBUG
# define CT_(x) NULL
#else
# define do_xstr(x) #x
# define xstr(x) do_xstr(x)
# define CT_(x) __FILE_ ":" xstr(__LINE__) " " x
#endif

so each CTRACE record will be preceeded with the name of the file and the line
where CTRACE was invoked.


 Best regards,
  -Vlad