Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!hao!husc6!mit-eddie!uw-beaver!uw-june!brian
From: brian@uw-june.UUCP (Brian Bershad)
Newsgroups: comp.lang.c++
Subject: problems with ld and static constructors
Message-ID: <3901@uw-june.UUCP>
Date: 31 Dec 87 17:19:50 GMT
Reply-To: brian@uw-june.UUCP (Brian Bershad)
Organization: U of Washington, Computer Science, Seattle
Lines: 50
Keywords: bug, munch, static constructors


If definitions for static vars having constructors are in a file
that has nothing else (or nothing else called by the rest of the program),
and that file is placed in an 'ar' archive, the pre-munch pass
of ld does not pull that file in.  So, nm does not see the STI defs,
and munch can't do the right thing.  

Try:


mystream.c:
----------------
#include <stream.h>
char pcout_buf[BUFSIZE];
filebuf pcout_file(stdout);	// UNIX output stream 1
ostream pcout(&pcout_file);
----------------

main.c:
---------------
#include <stream.h>
extern ostream pcout;
main()
{
	pcout << "Hello World\n";
}


With:
	CC -c mystream.c main.c
	CC mystream.o main.o
all is well, but with
	CC -c mystream.c main.c
	ar r foo.a mystream.o
	CC main.o foo.a

a seg fault occurs on the first call to pcout since it isn't getting
properly constructed.  

A kludge is to put a function in mystream.c that gets called from main.c
so as to pull the whole file in.  Anyone have a better one?





-- 
brian@june.cs.washington.edu                	Brian Bershad
{ihnp4,decvax,ucbvax}!uw-beaver!uw-june!brian   Dept. of Computer Science, FR-35
						University of Washington
                                                Seattle, WA 98195