-@c Copyright (C) 1995-1998 Free Software Foundation, Inc.
+@c Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
@c This is part of the G77 manual.
@c For copying conditions, see the file g77.texi.
-@c When changing the above copyright notice, be sure to
-@c change the one in `bugs0.texi' accordingly, to effect
-@c the change in the derived file `BUGS'.
-
@c The text of this file appears in the file BUGS
@c in the G77 distribution, as well as in the G77 manual.
-@c 1999-03-03
+@c Keep this the same as the dates above, since it's used
+@c in the standalone derivations of this file (e.g. BUGS).
+@set copyrights-bugs 1995,1996,1997,1998,1999,2000,2001
+
+@set last-update-bugs 2001-06-10
+
+@include root.texi
+
+@ifset DOC-BUGS
+@c The immediately following lines apply to the BUGS file
+@c which is derived from this file.
+@emph{Note:} This file is automatically generated from the files
+@file{bugs0.texi} and @file{bugs.texi}.
+@file{BUGS} is @emph{not} a source file,
+although it is normally included within source distributions.
+
+This file lists known bugs in the @value{which-g77} version
+of the GNU Fortran compiler.
+Copyright (C) @value{copyrights-bugs} Free Software Foundation, Inc.
+You may copy, distribute, and modify it freely as long as you preserve
+this copyright notice and permission notice.
-@ifclear BUGSONLY
-@node Actual Bugs
-@section Actual Bugs We Haven't Fixed Yet
-@end ifclear
+@node Top,,, (dir)
+@chapter Known Bugs In GNU Fortran
+@end ifset
+
+@ifset DOC-G77
+@node Known Bugs
+@section Known Bugs In GNU Fortran
+@end ifset
This section identifies bugs that @code{g77} @emph{users}
-might run into in
-@ifhtml
-the current development
-@end ifhtml
-version
-@ifnothtml
-@value{version-g77}
-@end ifnothtml
+might run into in the @value{which-g77} version
of @code{g77}.
This includes bugs that are actually in the @code{gcc}
back end (GBE) or in @code{libf2c}, because those
of (and necessarily intertwined with) @code{g77},
so it isn't worth separating them out.
+@ifset DOC-G77
For information on bugs in @emph{other} versions of @code{g77},
-@ifhtml
-see the page on Fortran news.
-@end ifhtml
-@ifnothtml
-@ref{News,,News About GNU Fortran}.
-@end ifnothtml
-
-For information on bugs that might afflict people who
-configure, port, build, and install @code{g77},
-@ifhtml
-see the chapter on installing in the @code{g77} documentation.
-@end ifhtml
-@ifnothtml
-@ref{Problems Installing}.
-@end ifnothtml
+see @ref{News,,News About GNU Fortran}.
+There, lists of bugs fixed in various versions of @code{g77}
+can help determine what bugs existed in prior versions.
+@end ifset
-@itemize @bullet
-@item
-@c Tim Prince discovered this.
-Automatic arrays possibly aren't working on HP-UX systems,
-at least in HP-UX version 10.20.
-Writing into them apparently causes over-writing
-of statically declared data in the main program.
-This probably means the arrays themselves are being under-allocated,
-or pointers to them being improperly handled,
-e.g. not passed to other procedures as they should be.
+@ifset DOC-BUGS
+For information on bugs in @emph{other} versions of @code{g77},
+see @file{@value{path-g77}/NEWS}.
+There, lists of bugs fixed in various versions of @code{g77}
+can help determine what bugs existed in prior versions.
+@end ifset
+
+@ifset DEVELOPMENT
+@emph{Warning:} The information below is still under development,
+and might not accurately reflect the @code{g77} code base
+of which it is a part.
+Efforts are made to keep it somewhat up-to-date,
+but they are particularly concentrated
+on any version of this information
+that is distributed as part of a @emph{released} @code{g77}.
+
+In particular, while this information is intended to apply to
+the @value{which-g77} version of @code{g77},
+only an official @emph{release} of that version
+is expected to contain documentation that is
+most consistent with the @code{g77} product in that version.
+@end ifset
+
+An online, ``live'' version of this document
+(derived directly from the mainline, development version
+of @code{g77} within @code{gcc})
+is available via
+@uref{http://www.gnu.org/software/gcc/onlinedocs/g77_bugs.html}.
+Follow the ``Known Bugs'' link.
+
+The following information was last updated on @value{last-update-bugs}:
+@itemize @bullet
@item
@code{g77} fails to warn about
use of a ``live'' iterative-DO variable
as an implied-DO variable
-in a @samp{WRITE} or @samp{PRINT} statement
-(although it does warn about this in a @samp{READ} statement).
+in a @code{WRITE} or @code{PRINT} statement
+(although it does warn about this in a @code{READ} statement).
@item
Something about @code{g77}'s straightforward handling of
Note that @code{g77} does display a warning message to
notify the user before the compiler appears to hang.
-@ifhtml
-See the @code{g77} installation documentation
-@end ifhtml
-@ifnothtml
-@xref{Large Initialization,,Initialization of Large Aggregate Areas},
-@end ifnothtml
-for information on how to change the point at which
-@code{g77} decides to issue this warning.
-
-@cindex debugging
-@cindex common blocks
-@cindex equivalence areas
-@cindex local equivalence areas
-@item
-@code{g77} doesn't emit variable and array members of common blocks for use
-with a debugger (the @samp{-g} command-line option).
-The code is present to do this, but doesn't work with at least
-one debug format---perhaps it works with others.
-And it turns out there's a similar bug for
-local equivalence areas, so that has been disabled as well.
-
-As of Version 0.5.19, a temporary kludge solution is provided whereby
-some rudimentary information on a member is written as a string that
-is the member's value as a character string.
-
-@ifhtml
-See the @code{g77} documentation
-@end ifhtml
-@ifnothtml
-@xref{Code Gen Options,,Options for Code Generation Conventions},
-@end ifnothtml
-for information on the @samp{-fdebug-kludge} option.
+@ifset DOC-G77
+A warning message is issued when @code{g77} sees code that provides
+initial values (e.g. via @code{DATA}) to an aggregate area (@code{COMMON}
+or @code{EQUIVALENCE}, or even a large enough array or @code{CHARACTER}
+variable)
+that is large enough to increase @code{g77}'s compile time by roughly
+a factor of 10.
+
+This size currently is quite small, since @code{g77}
+currently has a known bug requiring too much memory
+and time to handle such cases.
+In @file{@value{path-g77}/data.c}, the macro
+@code{FFEDATA_sizeTOO_BIG_INIT_} is defined
+to the minimum size for the warning to appear.
+The size is specified in storage units,
+which can be bytes, words, or whatever, on a case-by-case basis.
+
+After changing this macro definition, you must
+(of course) rebuild and reinstall @code{g77} for
+the change to take effect.
+
+Note that, as of version 0.5.18, improvements have
+reduced the scope of the problem for @emph{sparse}
+initialization of large arrays, especially those
+with large, contiguous uninitialized areas.
+However, the warning is issued at a point prior to
+when @code{g77} knows whether the initialization is sparse,
+and delaying the warning could mean it is produced
+too late to be helpful.
+
+Therefore, the macro definition should not be adjusted to
+reflect sparse cases.
+Instead, adjust it to generate the warning when densely
+initialized arrays begin to cause responses noticeably slower
+than linear performance would suggest.
+@end ifset
@cindex code, displaying main source
@cindex displaying main source code
@item
When debugging, after starting up the debugger but before being able
to see the source code for the main program unit, the user must currently
-set a breakpoint at @samp{MAIN__} (or @samp{MAIN___} or @samp{MAIN_} if
-@samp{MAIN__} doesn't exist)
+set a breakpoint at @code{MAIN__} (or @code{MAIN___} or @code{MAIN_} if
+@code{MAIN__} doesn't exist)
and run the program until it hits the breakpoint.
At that point, the
main program unit is activated and about to execute its first
Version 0.6 should solve most or all remaining problems
(such as cross-compiling involving 64-bit machines).
-@cindex COMPLEX support
-@cindex support, COMPLEX
-@item
-Maintainers of @code{gcc} report that the back end definitely has ``broken''
-support for @code{COMPLEX} types.
-Based on their input, it seems many of
-the problems affect only the more-general facilities for gcc's
-@code{__complex__} type, such as @code{__complex__ int}
-(where the real and imaginary parts are integers) that GNU
-Fortran does not use.
-
-Version 0.5.20 of @code{g77} works around this
-problem by not using the back end's support for @code{COMPLEX}.
-The new option @samp{-fno-emulate-complex} avoids the work-around,
-reverting to using the same ``broken'' mechanism as that used
-by versions of @code{g77} prior to 0.5.20.
-
@cindex padding
@cindex structures
@cindex common blocks
and front ends like @code{g77} should take advantage of this
when it becomes available.
-@cindex alignment
-@cindex double-precision performance
-@cindex -malign-double
-@item
-The x86 target's @samp{-malign-double} option
-no longer reliably aligns double-precision variables and arrays
-when they are placed in the stack frame.
-
-This can significantly reduce the performance of some applications,
-even on a run-to-run basis
-(that is, performance measurements can vary fairly widely
-depending on whether frequently used variables are properly aligned,
-and that can change from one program run to the next,
-even from one procedure call to the next).
-
-Versions 0.5.22 and earlier of @code{g77}
-included a patch to @code{gcc} that enabled this,
-but that patch has been deemed an improper (probably buggy) one
-for version 2.8 of @code{gcc} and for @code{egcs}.
-
-Note that version 1.1 of @code{egcs}
-aligns double-precision variables and arrays
-when they are in static storage
-even if @samp{-malign-double} is not specified.
-
-There is ongoing investigation into
-how to make @samp{-malign-double} work properly,
-also into how to make it unnecessary to get
-all double-precision variables and arrays aligned
-when such alignment would not violate
-the relevant specifications for processor
-and inter-procedural interfaces.
-
-For a suite of programs to test double-precision alignment,
-see @uref{ftp://alpha.gnu.org/gnu/g77/align/}.
-
@cindex complex performance
@cindex aliasing
@item
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