>Number:         14222
>Category:       bin
>Synopsis:       new toolchain's g77 won't compile and link anything
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Oct 10 21:17:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     Jim Bernard
>Release:        October 6, 2001
>Organization:
>Environment:
System: NetBSD roc 1.5Y NetBSD 1.5Y (ROC-$Revision: 1.8 $) #0: Sat Oct 6 15:16:01 MDT 2001 jim@roc:/tmp/compile/sys/arch/i386/compile/ROC i386
Architecture: i386
Machine: i386
>Description:
	The version of g77 in the new toolchain (gcc 2.95.3) is unable to
	compile and link any fortran programs.  The errors given are:

	  /usr/lib/libg2c.so: undefined reference to `G77_vxtidate_y2kbuggy_0'
	  /usr/lib/libg2c.so: undefined reference to `G77_date_y2kbuggy_0'

	The origin of the problem appears to be that these undefined text
	symbols were intentionally introduced into libg2c to help locate
	y2k problems in fortran code.  (See:
	info g77 Compiler "Run-time Environment Limits" "Year 2000 (Y2K) Problems"
	for the details.)

	Unfortunately, this means it is now impossible to write a fortran
	program that will link, because this trap is triggered even if there
	is no source code whatsoever (and certainly no intrinsics, y2k
	noncompliant or otherwise) in the program, except for the required
	END statement!

	I suspect what happens is that the linker tries to resolve all
	references to all the text symbols it finds in any referenced library,
	regardless of whether they are actually required to link the program.
	Thus, it always trips over the undefined symbols and refuses to
	generate an output file.

>How-To-Repeat:
	Create the most trivial of all fortran programs and try to compile it:

	  echo "      end" > x.f
	  f77 x.f

>Fix:
	Change the behavior of the linker or removed undefined symbols from
	libg2c?

	This would be a critical show stopper for anyone who uses fortran
	or for any packages that require the fortran compiler, except for
	the fact that it's possible to work around the problem by passing
	the -noinhibit-exec flag to the linker:

	  f77 -Wl,-noinhibit-exec x.f

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