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From: tbr@virgil.tfic.bc.ca (Tom Rushworth)
Newsgroups: comp.compilers
Subject: Re: Two pass compiler using YACC?
Keywords: yacc
Message-ID: <9008242036.AA10670@virgil.tfic.bc.ca>
Date: 24 Aug 90 20:36:19 GMT
Sender: compilers-sender@esegue.segue.boston.ma.us
Reply-To: tbr@virgil.tfic.bc.ca (Tom Rushworth)
Organization: Compilers Central
Lines: 43
Approved: compilers@esegue.segue.boston.ma.us

In article <1364@svin02.info.win.tue.nl> wsineel@info.win.tue.nl (e.vriezekolk)
says:
>The problems come during link-time, for ld, obviously, complains about
>multiple defined symbols (such as yylval and yyparse).


I have a number of library routines that need to parse different forms of
input, and I ran into the same problem (multiple yacc parsers in one program).
The brute force solution I used was in my makefile :

#-------------------------------------------------------
parse.c: definition.y
	yacc definition.y
	sed -f Makestatic <y.tab.c >$@
	rm y.tab.c
#-------------------------------------------------------
where Makestatic is:
#-------------------------------------------------------
/^extern int yychar/d
/^extern short yyerrflag/d
/^YYSTYPE/s//static &/
/^short yyexca/s//static &/
/^short yyact/s//static &/
/^short yypact/s//static &/
/^short yypgo/s//static &/
/^short yyr1/s//static &/
/^short yyr2/s//static &/
/^short yychk/s//static &/
/^short yydef/s//static &/
/^int yydebug/s//static &/
/^int yychar/s//static &/
/^int yynerrs/s//static &/
/^short yyerrflag/s//static &/
/^yyparse()/s//static &/
#-------------------------------------------------------

I then #include "parse.c" in the controlling code (instead of compiling it as
a separate module) and supply static versions of any of the externs deleted
in the script.  This all works (at least on my Sun3s & 4s), the only price you
pay is two (or more) copies of the parsing code.
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