+++ /dev/null
-@c Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002
-@c Free Software Foundation, Inc.
-@c This is part of the G77 manual.
-@c For copying conditions, see the file g77.texi.
-
-@ignore
-@c man begin COPYRIGHT
-Copyright @copyright{} 1996, 1997, 1998, 1999, 2000, 2001, 2002
-Free Software Foundation, Inc.
-
-Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.1 or
-any later version published by the Free Software Foundation; with the
-Invariant Sections being ``GNU General Public License'' and ``Funding
-Free Software'', the Front-Cover texts being (a) (see below), and with
-the Back-Cover Texts being (b) (see below). A copy of the license is
-included in the gfdl(7) man page.
-
-(a) The FSF's Front-Cover Text is:
-
- A GNU Manual
-
-(b) The FSF's Back-Cover Text is:
-
- You have freedom to copy and modify this GNU Manual, like GNU
- software. Copies published by the Free Software Foundation raise
- funds for GNU development.
-@c man end
-@c Set file name and title for the man page.
-@setfilename g77
-@settitle GNU project Fortran 77 compiler.
-@c man begin SYNOPSIS
-g77 [@option{-c}|@option{-S}|@option{-E}]
- [@option{-g}] [@option{-pg}] [@option{-O}@var{level}]
- [@option{-W}@var{warn}@dots{}] [@option{-pedantic}]
- [@option{-I}@var{dir}@dots{}] [@option{-L}@var{dir}@dots{}]
- [@option{-D}@var{macro}[=@var{defn}]@dots{}] [@option{-U}@var{macro}]
- [@option{-f}@var{option}@dots{}] [@option{-m}@var{machine-option}@dots{}]
- [@option{-o} @var{outfile}] @var{infile}@dots{}
-
-Only the most useful options are listed here; see below for the
-remainder.
-@c man end
-@c man begin SEEALSO
-gpl(7), gfdl(7), fsf-funding(7),
-cpp(1), gcov(1), gcc(1), as(1), ld(1), gdb(1), adb(1), dbx(1), sdb(1)
-and the Info entries for @file{gcc}, @file{cpp}, @file{g77}, @file{as},
-@file{ld}, @file{binutils} and @file{gdb}.
-@c man end
-@c man begin BUGS
-For instructions on reporting bugs, see
-@w{@uref{http://gcc.gnu.org/bugs.html}}. Use of the @command{gccbug}
-script to report bugs is recommended.
-@c man end
-@c man begin AUTHOR
-See the Info entry for @command{g77} for contributors to GCC and G77@.
-@c man end
-@end ignore
-
-@node Invoking G77
-@chapter GNU Fortran Command Options
-@cindex GNU Fortran command options
-@cindex command options
-@cindex options, GNU Fortran command
-
-@c man begin DESCRIPTION
-
-The @command{g77} command supports all the options supported by the
-@command{gcc} command.
-@xref{Invoking GCC,,GCC Command Options,gcc,Using the GNU Compiler
-Collection (GCC)}, for information
-on the non-Fortran-specific aspects of the @command{gcc} command (and,
-therefore, the @command{g77} command).
-
-@cindex options, negative forms
-@cindex negative forms of options
-All @command{gcc} and @command{g77} options
-are accepted both by @command{g77} and by @command{gcc}
-(as well as any other drivers built at the same time,
-such as @command{g++}),
-since adding @command{g77} to the @command{gcc} distribution
-enables acceptance of @command{g77} options
-by all of the relevant drivers.
-
-In some cases, options have positive and negative forms;
-the negative form of @option{-ffoo} would be @option{-fno-foo}.
-This manual documents only one of these two forms, whichever
-one is not the default.
-
-@c man end
-
-@menu
-* Option Summary:: Brief list of all @command{g77} options,
- without explanations.
-* Overall Options:: Controlling the kind of output:
- an executable, object files, assembler files,
- or preprocessed source.
-* Shorthand Options:: Options that are shorthand for other options.
-* Fortran Dialect Options:: Controlling the variant of Fortran language
- compiled.
-* Warning Options:: How picky should the compiler be?
-* Debugging Options:: Symbol tables, measurements, and debugging dumps.
-* Optimize Options:: How much optimization?
-* Preprocessor Options:: Controlling header files and macro definitions.
- Also, getting dependency information for Make.
-* Directory Options:: Where to find header files and libraries.
- Where to find the compiler executable files.
-* Code Gen Options:: Specifying conventions for function calls, data layout
- and register usage.
-* Environment Variables:: Env vars that affect GNU Fortran.
-@end menu
-
-@node Option Summary
-@section Option Summary
-
-@c man begin OPTIONS
-
-Here is a summary of all the options specific to GNU Fortran, grouped
-by type. Explanations are in the following sections.
-
-@table @emph
-@item Overall Options
-@xref{Overall Options,,Options Controlling the Kind of Output}.
-@gccoptlist{
--fversion -fset-g77-defaults -fno-silent}
-
-@item Shorthand Options
-@xref{Shorthand Options}.
-@gccoptlist{
--ff66 -fno-f66 -ff77 -fno-f77 -fno-ugly}
-
-@item Fortran Language Options
-@xref{Fortran Dialect Options,,Options Controlling Fortran Dialect}.
-@gccoptlist{
--ffree-form -fno-fixed-form -ff90 @gol
--fvxt -fdollar-ok -fno-backslash @gol
--fno-ugly-args -fno-ugly-assign -fno-ugly-assumed @gol
--fugly-comma -fugly-complex -fugly-init -fugly-logint @gol
--fonetrip -ftypeless-boz @gol
--fintrin-case-initcap -fintrin-case-upper @gol
--fintrin-case-lower -fintrin-case-any @gol
--fmatch-case-initcap -fmatch-case-upper @gol
--fmatch-case-lower -fmatch-case-any @gol
--fsource-case-upper -fsource-case-lower @gol
--fsource-case-preserve @gol
--fsymbol-case-initcap -fsymbol-case-upper @gol
--fsymbol-case-lower -fsymbol-case-any @gol
--fcase-strict-upper -fcase-strict-lower @gol
--fcase-initcap -fcase-upper -fcase-lower -fcase-preserve @gol
--ff2c-intrinsics-delete -ff2c-intrinsics-hide @gol
--ff2c-intrinsics-disable -ff2c-intrinsics-enable @gol
--fbadu77-intrinsics-delete -fbadu77-intrinsics-hide @gol
--fbadu77-intrinsics-disable -fbadu77-intrinsics-enable @gol
--ff90-intrinsics-delete -ff90-intrinsics-hide @gol
--ff90-intrinsics-disable -ff90-intrinsics-enable @gol
--fgnu-intrinsics-delete -fgnu-intrinsics-hide @gol
--fgnu-intrinsics-disable -fgnu-intrinsics-enable @gol
--fmil-intrinsics-delete -fmil-intrinsics-hide @gol
--fmil-intrinsics-disable -fmil-intrinsics-enable @gol
--funix-intrinsics-delete -funix-intrinsics-hide @gol
--funix-intrinsics-disable -funix-intrinsics-enable @gol
--fvxt-intrinsics-delete -fvxt-intrinsics-hide @gol
--fvxt-intrinsics-disable -fvxt-intrinsics-enable @gol
--ffixed-line-length-@var{n} -ffixed-line-length-none}
-
-@item Warning Options
-@xref{Warning Options,,Options to Request or Suppress Warnings}.
-@gccoptlist{
--fsyntax-only -pedantic -pedantic-errors -fpedantic @gol
--w -Wno-globals -Wimplicit -Wunused -Wuninitialized @gol
--Wall -Wsurprising @gol
--Werror -W}
-
-@item Debugging Options
-@xref{Debugging Options,,Options for Debugging Your Program or GCC}.
-@gccoptlist{
--g}
-
-@item Optimization Options
-@xref{Optimize Options,,Options that Control Optimization}.
-@gccoptlist{
--malign-double @gol
--ffloat-store -fforce-mem -fforce-addr -fno-inline @gol
--ffast-math -fstrength-reduce -frerun-cse-after-loop @gol
--funsafe-math-optimizations -fno-trapping-math @gol
--fexpensive-optimizations -fdelayed-branch @gol
--fschedule-insns -fschedule-insn2 -fcaller-saves @gol
--funroll-loops -funroll-all-loops @gol
--fno-move-all-movables -fno-reduce-all-givs @gol
--fno-rerun-loop-opt}
-
-@item Directory Options
-@xref{Directory Options,,Options for Directory Search}.
-@gccoptlist{
--I@var{dir} -I-}
-
-@item Code Generation Options
-@xref{Code Gen Options,,Options for Code Generation Conventions}.
-@gccoptlist{
--fno-automatic -finit-local-zero -fno-f2c @gol
--ff2c-library -fno-underscoring -fno-ident @gol
--fpcc-struct-return -freg-struct-return @gol
--fshort-double -fno-common -fpack-struct @gol
--fzeros -fno-second-underscore @gol
--femulate-complex @gol
--falias-check -fargument-alias @gol
--fargument-noalias -fno-argument-noalias-global @gol
--fno-globals -fflatten-arrays @gol
--fbounds-check -ffortran-bounds-check}
-@end table
-
-@c man end
-
-@menu
-* Overall Options:: Controlling the kind of output:
- an executable, object files, assembler files,
- or preprocessed source.
-* Shorthand Options:: Options that are shorthand for other options.
-* Fortran Dialect Options:: Controlling the variant of Fortran language
- compiled.
-* Warning Options:: How picky should the compiler be?
-* Debugging Options:: Symbol tables, measurements, and debugging dumps.
-* Optimize Options:: How much optimization?
-* Preprocessor Options:: Controlling header files and macro definitions.
- Also, getting dependency information for Make.
-* Directory Options:: Where to find header files and libraries.
- Where to find the compiler executable files.
-* Code Gen Options:: Specifying conventions for function calls, data layout
- and register usage.
-@end menu
-
-@node Overall Options
-@section Options Controlling the Kind of Output
-@cindex overall options
-@cindex options, overall
-
-@c man begin OPTIONS
-
-Compilation can involve as many as four stages: preprocessing, code
-generation (often what is really meant by the term ``compilation''),
-assembly, and linking, always in that order. The first three
-stages apply to an individual source file, and end by producing an
-object file; linking combines all the object files (those newly
-compiled, and those specified as input) into an executable file.
-
-@cindex file name suffix
-@cindex suffixes, file name
-@cindex file name extension
-@cindex extensions, file name
-@cindex file type
-@cindex types, file
-For any given input file, the file name suffix determines what kind of
-program is contained in the file---that is, the language in which the
-program is written is generally indicated by the suffix.
-Suffixes specific to GNU Fortran are listed below.
-@xref{Overall Options,,Options Controlling the Kind of
-Output,gcc,Using the GNU Compiler Collection (GCC)}, for
-information on suffixes recognized by GNU CC.
-
-@table @gcctabopt
-@cindex .f filename suffix
-@cindex .for filename suffix
-@cindex .FOR filename suffix
-@item @var{file}.f
-@item @var{file}.for
-@item @var{file}.FOR
-Fortran source code that should not be preprocessed.
-
-Such source code cannot contain any preprocessor directives, such
-as @code{#include}, @code{#define}, @code{#if}, and so on.
-
-You can force @samp{.f} files to be preprocessed by @command{cpp} by using
-@option{-x f77-cpp-input}.
-@xref{LEX}.
-
-@cindex preprocessor
-@cindex C preprocessor
-@cindex cpp preprocessor
-@cindex Fortran preprocessor
-@cindex cpp program
-@cindex programs, cpp
-@cindex .F filename suffix
-@cindex .fpp filename suffix
-@cindex .FPP filename suffix
-@item @var{file}.F
-@item @var{file}.fpp
-@item @var{file}.FPP
-Fortran source code that must be preprocessed (by the C preprocessor
-@command{cpp}, which is part of GNU CC).
-
-Note that preprocessing is not extended to the contents of
-files included by the @code{INCLUDE} directive---the @code{#include}
-preprocessor directive must be used instead.
-
-@cindex Ratfor preprocessor
-@cindex programs, @command{ratfor}
-@cindex @samp{.r} filename suffix
-@cindex @command{ratfor}
-@item @var{file}.r
-Ratfor source code, which must be preprocessed by the @command{ratfor}
-command, which is available separately (as it is not yet part of the GNU
-Fortran distribution).
-One version in Fortran, adapted for use with @command{g77} is at
-@uref{ftp://members.aol.com/n8tm/rat7.uue} (of uncertain copyright
-status). Another, public domain version in C is at
-@uref{http://sepwww.stanford.edu/sep/prof/ratfor.shar.2}.
-@end table
-
-UNIX users typically use the @file{@var{file}.f} and @file{@var{file}.F}
-nomenclature.
-Users of other operating systems, especially those that cannot
-distinguish upper-case
-letters from lower-case letters in their file names, typically use
-the @file{@var{file}.for} and @file{@var{file}.fpp} nomenclature.
-
-@cindex #define
-@cindex #include
-@cindex #if
-Use of the preprocessor @command{cpp} allows use of C-like
-constructs such as @code{#define} and @code{#include}, but can
-lead to unexpected, even mistaken, results due to Fortran's source file
-format.
-It is recommended that use of the C preprocessor
-be limited to @code{#include} and, in
-conjunction with @code{#define}, only @code{#if} and related directives,
-thus avoiding in-line macro expansion entirely.
-This recommendation applies especially
-when using the traditional fixed source form.
-With free source form,
-fewer unexpected transformations are likely to happen, but use of
-constructs such as Hollerith and character constants can nevertheless
-present problems, especially when these are continued across multiple
-source lines.
-These problems result, primarily, from differences between the way
-such constants are interpreted by the C preprocessor and by a Fortran
-compiler.
-
-Another example of a problem that results from using the C preprocessor
-is that a Fortran comment line that happens to contain any
-characters ``interesting'' to the C preprocessor,
-such as a backslash at the end of the line,
-is not recognized by the preprocessor as a comment line,
-so instead of being passed through ``raw'',
-the line is edited according to the rules for the preprocessor.
-For example, the backslash at the end of the line is removed,
-along with the subsequent newline, resulting in the next
-line being effectively commented out---unfortunate if that
-line is a non-comment line of important code!
-
-@emph{Note:} The @option{-traditional} and @option{-undef} flags are supplied
-to @command{cpp} by default, to help avoid unpleasant surprises.
-@xref{Preprocessor Options,,Options Controlling the Preprocessor,
-gcc,Using the GNU Compiler Collection (GCC)}.
-This means that ANSI C preprocessor features (such as the @samp{#}
-operator) aren't available, and only variables in the C reserved
-namespace (generally, names with a leading underscore) are liable to
-substitution by C predefines.
-Thus, if you want to do system-specific
-tests, use, for example, @samp{#ifdef __linux__} rather than @samp{#ifdef linux}.
-Use the @option{-v} option to see exactly how the preprocessor is invoked.
-
-@cindex /*
-Unfortunately, the @option{-traditional} flag will not avoid an error from
-anything that @command{cpp} sees as an unterminated C comment, such as:
-@smallexample
-C Some Fortran compilers accept /* as starting
-C an inline comment.
-@end smallexample
-@xref{Trailing Comment}.
-
-The following options that affect overall processing are recognized
-by the @command{g77} and @command{gcc} commands in a GNU Fortran installation:
-
-@table @gcctabopt
-@cindex -fversion option
-@cindex options, -fversion
-@cindex printing version information
-@cindex version information, printing
-@cindex consistency checks
-@cindex internal consistency checks
-@cindex checks, of internal consistency
-@item -fversion
-Ensure that the @command{g77} version of the compiler phase is reported,
-if run,
-and, starting in @code{egcs} version 1.1,
-that internal consistency checks in the @file{f771} program are run.
-
-This option is supplied automatically when @option{-v} or @option{--verbose}
-is specified as a command-line option for @command{g77} or @command{gcc}
-and when the resulting commands compile Fortran source files.
-
-In GCC 3.1, this is changed back to the behaviour @command{gcc} displays
-for @samp{.c} files.
-
-@cindex -fset-g77-defaults option
-@cindex options, -fset-g77-defaults
-@item -fset-g77-defaults
-@emph{Version info:}
-This option was obsolete as of @code{egcs}
-version 1.1.
-The effect is instead achieved
-by the @code{lang_init_options} routine
-in @file{gcc/gcc/f/com.c}.
-
-@cindex consistency checks
-@cindex internal consistency checks
-@cindex checks, of internal consistency
-Set up whatever @command{gcc} options are to apply to Fortran
-compilations, and avoid running internal consistency checks
-that might take some time.
-
-This option is supplied automatically when compiling Fortran code
-via the @command{g77} or @command{gcc} command.
-The description of this option is provided so that users seeing
-it in the output of, say, @samp{g77 -v} understand why it is
-there.
-
-@cindex modifying @command{g77}
-@cindex @command{g77}, modifying
-Also, developers who run @code{f771} directly might want to specify it
-by hand to get the same defaults as they would running @code{f771}
-via @command{g77} or @command{gcc}
-However, such developers should, after linking a new @code{f771}
-executable, invoke it without this option once,
-e.g. via @kbd{./f771 -quiet < /dev/null},
-to ensure that they have not introduced any
-internal inconsistencies (such as in the table of
-intrinsics) before proceeding---@command{g77} will crash
-with a diagnostic if it detects an inconsistency.
-
-@cindex -fno-silent option
-@cindex options, -fno-silent
-@cindex f2c compatibility
-@cindex compatibility, f2c
-@cindex status, compilation
-@cindex compilation, status
-@cindex reporting compilation status
-@cindex printing compilation status
-@item -fno-silent
-Print (to @code{stderr}) the names of the program units as
-they are compiled, in a form similar to that used by popular
-UNIX @command{f77} implementations and @command{f2c}
-@end table
-
-@xref{Overall Options,,Options Controlling the Kind of Output,
-gcc,Using the GNU Compiler Collection (GCC)}, for information
-on more options that control the overall operation of the @command{gcc} command
-(and, by extension, the @command{g77} command).
-
-@node Shorthand Options
-@section Shorthand Options
-@cindex shorthand options
-@cindex options, shorthand
-@cindex macro options
-@cindex options, macro
-
-The following options serve as ``shorthand''
-for other options accepted by the compiler:
-
-@table @gcctabopt
-@cindex -fugly option
-@cindex options, -fugly
-@item -fugly
-@cindex ugly features
-@cindex features, ugly
-@emph{Note:} This option is no longer supported.
-The information, below, is provided to aid
-in the conversion of old scripts.
-
-Specify that certain ``ugly'' constructs are to be quietly accepted.
-Same as:
-
-@smallexample
--fugly-args -fugly-assign -fugly-assumed
--fugly-comma -fugly-complex -fugly-init
--fugly-logint
-@end smallexample
-
-These constructs are considered inappropriate to use in new
-or well-maintained portable Fortran code, but widely used
-in old code.
-@xref{Distensions}, for more information.
-
-@cindex -fno-ugly option
-@cindex options, -fno-ugly
-@item -fno-ugly
-@cindex ugly features
-@cindex features, ugly
-Specify that all ``ugly'' constructs are to be noisily rejected.
-Same as:
-
-@smallexample
--fno-ugly-args -fno-ugly-assign -fno-ugly-assumed
--fno-ugly-comma -fno-ugly-complex -fno-ugly-init
--fno-ugly-logint
-@end smallexample
-
-@xref{Distensions}, for more information.
-
-@cindex -ff66 option
-@cindex options, -ff66
-@item -ff66
-@cindex FORTRAN 66
-@cindex compatibility, FORTRAN 66
-Specify that the program is written in idiomatic FORTRAN 66.
-Same as @samp{-fonetrip -fugly-assumed}.
-
-The @option{-fno-f66} option is the inverse of @option{-ff66}.
-As such, it is the same as @samp{-fno-onetrip -fno-ugly-assumed}.
-
-The meaning of this option is likely to be refined as future
-versions of @command{g77} provide more compatibility with other
-existing and obsolete Fortran implementations.
-
-@cindex -ff77 option
-@cindex options, -ff77
-@item -ff77
-@cindex UNIX f77
-@cindex f2c compatibility
-@cindex compatibility, f2c
-@cindex f77 compatibility
-@cindex compatibility, f77
-Specify that the program is written in idiomatic UNIX FORTRAN 77
-and/or the dialect accepted by the @command{f2c} product.
-Same as @samp{-fbackslash -fno-typeless-boz}.
-
-The meaning of this option is likely to be refined as future
-versions of @command{g77} provide more compatibility with other
-existing and obsolete Fortran implementations.
-
-@cindex -fno-f77 option
-@cindex options, -fno-f77
-@item -fno-f77
-@cindex UNIX f77
-The @option{-fno-f77} option is @emph{not} the inverse
-of @option{-ff77}.
-It specifies that the program is not written in idiomatic UNIX
-FORTRAN 77 or @command{f2c} but in a more widely portable dialect.
-@option{-fno-f77} is the same as @option{-fno-backslash}.
-
-The meaning of this option is likely to be refined as future
-versions of @command{g77} provide more compatibility with other
-existing and obsolete Fortran implementations.
-@end table
-
-@node Fortran Dialect Options
-@section Options Controlling Fortran Dialect
-@cindex dialect options
-@cindex language, dialect options
-@cindex options, dialect
-
-The following options control the dialect of Fortran
-that the compiler accepts:
-
-@table @gcctabopt
-@cindex -ffree-form option
-@cindex options, -ffree-form
-@cindex -fno-fixed-form option
-@cindex options, -fno-fixed-form
-@cindex source file format
-@cindex free form
-@cindex fixed form
-@cindex Fortran 90, features
-@item -ffree-form
-@item -fno-fixed-form
-Specify that the source file is written in free form
-(introduced in Fortran 90) instead of the more-traditional fixed form.
-
-@cindex -ff90 option
-@cindex options, -ff90
-@cindex Fortran 90, features
-@item -ff90
-Allow certain Fortran-90 constructs.
-
-This option controls whether certain
-Fortran 90 constructs are recognized.
-(Other Fortran 90 constructs
-might or might not be recognized depending on other options such as
-@option{-fvxt}, @option{-ff90-intrinsics-enable}, and the
-current level of support for Fortran 90.)
-
-@xref{Fortran 90}, for more information.
-
-@cindex -fvxt option
-@cindex options, -fvxt
-@item -fvxt
-@cindex Fortran 90, features
-@cindex VXT extensions
-Specify the treatment of certain constructs that have different
-meanings depending on whether the code is written in
-GNU Fortran (based on FORTRAN 77 and akin to Fortran 90)
-or VXT Fortran (more like VAX FORTRAN).
-
-The default is @option{-fno-vxt}.
-@option{-fvxt} specifies that the VXT Fortran interpretations
-for those constructs are to be chosen.
-
-@xref{VXT Fortran}, for more information.
-
-@cindex -fdollar-ok option
-@cindex options, -fdollar-ok
-@item -fdollar-ok
-@cindex dollar sign
-@cindex symbol names
-@cindex character set
-Allow @samp{$} as a valid character in a symbol name.
-
-@cindex -fno-backslash option
-@cindex options, -fno-backslash
-@item -fno-backslash
-@cindex backslash
-@cindex character constants
-@cindex Hollerith constants
-Specify that @samp{\} is not to be specially interpreted in character
-and Hollerith constants a la C and many UNIX Fortran compilers.
-
-For example, with @option{-fbackslash} in effect, @samp{A\nB} specifies
-three characters, with the second one being newline.
-With @option{-fno-backslash}, it specifies four characters,
-@samp{A}, @samp{\}, @samp{n}, and @samp{B}.
-
-Note that @command{g77} implements a fairly general form of backslash
-processing that is incompatible with the narrower forms supported
-by some other compilers.
-For example, @samp{'A\003B'} is a three-character string in @command{g77}
-whereas other compilers that support backslash might not support
-the three-octal-digit form, and thus treat that string as longer
-than three characters.
-
-@xref{Backslash in Constants}, for
-information on why @option{-fbackslash} is the default
-instead of @option{-fno-backslash}.
-
-@cindex -fno-ugly-args option
-@cindex options, -fno-ugly-args
-@item -fno-ugly-args
-Disallow passing Hollerith and typeless constants as actual
-arguments (for example, @samp{CALL FOO(4HABCD)}).
-
-@xref{Ugly Implicit Argument Conversion}, for more information.
-
-@cindex -fugly-assign option
-@cindex options, -fugly-assign
-@item -fugly-assign
-Use the same storage for a given variable regardless of
-whether it is used to hold an assigned-statement label
-(as in @samp{ASSIGN 10 TO I}) or used to hold numeric data
-(as in @samp{I = 3}).
-
-@xref{Ugly Assigned Labels}, for more information.
-
-@cindex -fugly-assumed option
-@cindex options, -fugly-assumed
-@item -fugly-assumed
-Assume any dummy array with a final dimension specified as @samp{1}
-is really an assumed-size array, as if @samp{*} had been specified
-for the final dimension instead of @samp{1}.
-
-For example, @samp{DIMENSION X(1)} is treated as if it
-had read @samp{DIMENSION X(*)}.
-
-@xref{Ugly Assumed-Size Arrays}, for more information.
-
-@cindex -fugly-comma option
-@cindex options, -fugly-comma
-@item -fugly-comma
-In an external-procedure invocation,
-treat a trailing comma in the argument list
-as specification of a trailing null argument,
-and treat an empty argument list
-as specification of a single null argument.
-
-For example, @samp{CALL FOO(,)} is treated as
-@samp{CALL FOO(%VAL(0), %VAL(0))}.
-That is, @emph{two} null arguments are specified
-by the procedure call when @option{-fugly-comma} is in force.
-And @samp{F = FUNC()} is treated as @samp{F = FUNC(%VAL(0))}.
-
-The default behavior, @option{-fno-ugly-comma}, is to ignore
-a single trailing comma in an argument list.
-So, by default, @samp{CALL FOO(X,)} is treated
-exactly the same as @samp{CALL FOO(X)}.
-
-@xref{Ugly Null Arguments}, for more information.
-
-@cindex -fugly-complex option
-@cindex options, -fugly-complex
-@item -fugly-complex
-Do not complain about @samp{REAL(@var{expr})} or
-@samp{AIMAG(@var{expr})} when @var{expr} is a @code{COMPLEX}
-type other than @code{COMPLEX(KIND=1)}---usually
-this is used to permit @code{COMPLEX(KIND=2)}
-(@code{DOUBLE COMPLEX}) operands.
-
-The @option{-ff90} option controls the interpretation
-of this construct.
-
-@xref{Ugly Complex Part Extraction}, for more information.
-
-@cindex -fno-ugly-init option
-@cindex options, -fno-ugly-init
-@item -fno-ugly-init
-Disallow use of Hollerith and typeless constants as initial
-values (in @code{PARAMETER} and @code{DATA} statements), and
-use of character constants to
-initialize numeric types and vice versa.
-
-For example, @samp{DATA I/'F'/, CHRVAR/65/, J/4HABCD/} is disallowed by
-@option{-fno-ugly-init}.
-
-@xref{Ugly Conversion of Initializers}, for more information.
-
-@cindex -fugly-logint option
-@cindex options, -fugly-logint
-@item -fugly-logint
-Treat @code{INTEGER} and @code{LOGICAL} variables and
-expressions as potential stand-ins for each other.
-
-For example, automatic conversion between @code{INTEGER} and
-@code{LOGICAL} is enabled, for many contexts, via this option.
-
-@xref{Ugly Integer Conversions}, for more information.
-
-@cindex -fonetrip option
-@cindex options, -fonetrip
-@item -fonetrip
-@cindex FORTRAN 66
-@cindex @code{DO} loops, one-trip
-@cindex one-trip @code{DO} loops
-@cindex @code{DO} loops, zero-trip
-@cindex zero-trip @code{DO} loops
-@cindex compatibility, FORTRAN 66
-Executable iterative @code{DO} loops are to be executed at
-least once each time they are reached.
-
-ANSI FORTRAN 77 and more recent versions of the Fortran standard
-specify that the body of an iterative @code{DO} loop is not executed
-if the number of iterations calculated from the parameters of the
-loop is less than 1.
-(For example, @samp{DO 10 I = 1, 0}.)
-Such a loop is called a @dfn{zero-trip loop}.
-
-Prior to ANSI FORTRAN 77, many compilers implemented @code{DO} loops
-such that the body of a loop would be executed at least once, even
-if the iteration count was zero.
-Fortran code written assuming this behavior is said to require
-@dfn{one-trip loops}.
-For example, some code written to the FORTRAN 66 standard
-expects this behavior from its @code{DO} loops, although that
-standard did not specify this behavior.
-
-The @option{-fonetrip} option specifies that the source file(s) being
-compiled require one-trip loops.
-
-This option affects only those loops specified by the (iterative) @code{DO}
-statement and by implied-@code{DO} lists in I/O statements.
-Loops specified by implied-@code{DO} lists in @code{DATA} and
-specification (non-executable) statements are not affected.
-
-@cindex -ftypeless-boz option
-@cindex options, -ftypeless-boz
-@cindex prefix-radix constants
-@cindex constants, prefix-radix
-@cindex constants, types
-@cindex types, constants
-@item -ftypeless-boz
-Specifies that prefix-radix non-decimal constants, such as
-@samp{Z'ABCD'}, are typeless instead of @code{INTEGER(KIND=1)}.
-
-You can test for yourself whether a particular compiler treats
-the prefix form as @code{INTEGER(KIND=1)} or typeless by running the
-following program:
-
-@smallexample
-EQUIVALENCE (I, R)
-R = Z'ABCD1234'
-J = Z'ABCD1234'
-IF (J .EQ. I) PRINT *, 'Prefix form is TYPELESS'
-IF (J .NE. I) PRINT *, 'Prefix form is INTEGER'
-END
-@end smallexample
-
-Reports indicate that many compilers process this form as
-@code{INTEGER(KIND=1)}, though a few as typeless, and at least one
-based on a command-line option specifying some kind of
-compatibility.
-
-@cindex -fintrin-case-initcap option
-@cindex options, -fintrin-case-initcap
-@item -fintrin-case-initcap
-@cindex -fintrin-case-upper option
-@cindex options, -fintrin-case-upper
-@item -fintrin-case-upper
-@cindex -fintrin-case-lower option
-@cindex options, -fintrin-case-lower
-@item -fintrin-case-lower
-@cindex -fintrin-case-any option
-@cindex options, -fintrin-case-any
-@item -fintrin-case-any
-Specify expected case for intrinsic names.
-@option{-fintrin-case-lower} is the default.
-
-@cindex -fmatch-case-initcap option
-@cindex options, -fmatch-case-initcap
-@item -fmatch-case-initcap
-@cindex -fmatch-case-upper option
-@cindex options, -fmatch-case-upper
-@item -fmatch-case-upper
-@cindex -fmatch-case-lower option
-@cindex options, -fmatch-case-lower
-@item -fmatch-case-lower
-@cindex -fmatch-case-any option
-@cindex options, -fmatch-case-any
-@item -fmatch-case-any
-Specify expected case for keywords.
-@option{-fmatch-case-lower} is the default.
-
-@cindex -fsource-case-upper option
-@cindex options, -fsource-case-upper
-@item -fsource-case-upper
-@cindex -fsource-case-lower option
-@cindex options, -fsource-case-lower
-@item -fsource-case-lower
-@cindex -fsource-case-preserve option
-@cindex options, -fsource-case-preserve
-@item -fsource-case-preserve
-Specify whether source text other than character and Hollerith constants
-is to be translated to uppercase, to lowercase, or preserved as is.
-@option{-fsource-case-lower} is the default.
-
-@cindex -fsymbol-case-initcap option
-@cindex options, -fsymbol-case-initcap
-@item -fsymbol-case-initcap
-@cindex -fsymbol-case-upper option
-@cindex options, -fsymbol-case-upper
-@item -fsymbol-case-upper
-@cindex -fsymbol-case-lower option
-@cindex options, -fsymbol-case-lower
-@item -fsymbol-case-lower
-@cindex -fsymbol-case-any option
-@cindex options, -fsymbol-case-any
-@item -fsymbol-case-any
-Specify valid cases for user-defined symbol names.
-@option{-fsymbol-case-any} is the default.
-
-@cindex -fcase-strict-upper option
-@cindex options, -fcase-strict-upper
-@item -fcase-strict-upper
-Same as @samp{-fintrin-case-upper -fmatch-case-upper -fsource-case-preserve
--fsymbol-case-upper}.
-(Requires all pertinent source to be in uppercase.)
-
-@cindex -fcase-strict-lower option
-@cindex options, -fcase-strict-lower
-@item -fcase-strict-lower
-Same as @samp{-fintrin-case-lower -fmatch-case-lower -fsource-case-preserve
--fsymbol-case-lower}.
-(Requires all pertinent source to be in lowercase.)
-
-@cindex -fcase-initcap option
-@cindex options, -fcase-initcap
-@item -fcase-initcap
-Same as @samp{-fintrin-case-initcap -fmatch-case-initcap -fsource-case-preserve
--fsymbol-case-initcap}.
-(Requires all pertinent source to be in initial capitals,
-as in @samp{Print *,SqRt(Value)}.)
-
-@cindex -fcase-upper option
-@cindex options, -fcase-upper
-@item -fcase-upper
-Same as @samp{-fintrin-case-any -fmatch-case-any -fsource-case-upper
--fsymbol-case-any}.
-(Maps all pertinent source to uppercase.)
-
-@cindex -fcase-lower option
-@cindex options, -fcase-lower
-@item -fcase-lower
-Same as @samp{-fintrin-case-any -fmatch-case-any -fsource-case-lower
--fsymbol-case-any}.
-(Maps all pertinent source to lowercase.)
-
-@cindex -fcase-preserve option
-@cindex options, -fcase-preserve
-@item -fcase-preserve
-Same as @samp{-fintrin-case-any -fmatch-case-any -fsource-case-preserve
--fsymbol-case-any}.
-(Preserves all case in user-defined symbols,
-while allowing any-case matching of intrinsics and keywords.
-For example, @samp{call Foo(i,I)} would pass two @emph{different}
-variables named @samp{i} and @samp{I} to a procedure named @samp{Foo}.)
-
-@cindex -fbadu77-intrinsics-delete option
-@cindex options, -fbadu77-intrinsics-delete
-@item -fbadu77-intrinsics-delete
-@cindex -fbadu77-intrinsics-hide option
-@cindex options, -fbadu77-intrinsics-hide
-@item -fbadu77-intrinsics-hide
-@cindex -fbadu77-intrinsics-disable option
-@cindex options, -fbadu77-intrinsics-disable
-@item -fbadu77-intrinsics-disable
-@cindex -fbadu77-intrinsics-enable option
-@cindex options, -fbadu77-intrinsics-enable
-@item -fbadu77-intrinsics-enable
-@cindex @code{badu77} intrinsics
-@cindex intrinsics, @code{badu77}
-Specify status of UNIX intrinsics having inappropriate forms.
-@option{-fbadu77-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -ff2c-intrinsics-delete option
-@cindex options, -ff2c-intrinsics-delete
-@item -ff2c-intrinsics-delete
-@cindex -ff2c-intrinsics-hide option
-@cindex options, -ff2c-intrinsics-hide
-@item -ff2c-intrinsics-hide
-@cindex -ff2c-intrinsics-disable option
-@cindex options, -ff2c-intrinsics-disable
-@item -ff2c-intrinsics-disable
-@cindex -ff2c-intrinsics-enable option
-@cindex options, -ff2c-intrinsics-enable
-@item -ff2c-intrinsics-enable
-@cindex @command{f2c} intrinsics
-@cindex intrinsics, @command{f2c}
-Specify status of f2c-specific intrinsics.
-@option{-ff2c-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -ff90-intrinsics-delete option
-@cindex options, -ff90-intrinsics-delete
-@item -ff90-intrinsics-delete
-@cindex -ff90-intrinsics-hide option
-@cindex options, -ff90-intrinsics-hide
-@item -ff90-intrinsics-hide
-@cindex -ff90-intrinsics-disable option
-@cindex options, -ff90-intrinsics-disable
-@item -ff90-intrinsics-disable
-@cindex -ff90-intrinsics-enable option
-@cindex options, -ff90-intrinsics-enable
-@item -ff90-intrinsics-enable
-@cindex Fortran 90, intrinsics
-@cindex intrinsics, Fortran 90
-Specify status of F90-specific intrinsics.
-@option{-ff90-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -fgnu-intrinsics-delete option
-@cindex options, -fgnu-intrinsics-delete
-@item -fgnu-intrinsics-delete
-@cindex -fgnu-intrinsics-hide option
-@cindex options, -fgnu-intrinsics-hide
-@item -fgnu-intrinsics-hide
-@cindex -fgnu-intrinsics-disable option
-@cindex options, -fgnu-intrinsics-disable
-@item -fgnu-intrinsics-disable
-@cindex -fgnu-intrinsics-enable option
-@cindex options, -fgnu-intrinsics-enable
-@item -fgnu-intrinsics-enable
-@cindex Digital Fortran features
-@cindex @code{COMPLEX} intrinsics
-@cindex intrinsics, @code{COMPLEX}
-Specify status of Digital's COMPLEX-related intrinsics.
-@option{-fgnu-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -fmil-intrinsics-delete option
-@cindex options, -fmil-intrinsics-delete
-@item -fmil-intrinsics-delete
-@cindex -fmil-intrinsics-hide option
-@cindex options, -fmil-intrinsics-hide
-@item -fmil-intrinsics-hide
-@cindex -fmil-intrinsics-disable option
-@cindex options, -fmil-intrinsics-disable
-@item -fmil-intrinsics-disable
-@cindex -fmil-intrinsics-enable option
-@cindex options, -fmil-intrinsics-enable
-@item -fmil-intrinsics-enable
-@cindex MIL-STD 1753
-@cindex intrinsics, MIL-STD 1753
-Specify status of MIL-STD-1753-specific intrinsics.
-@option{-fmil-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -funix-intrinsics-delete option
-@cindex options, -funix-intrinsics-delete
-@item -funix-intrinsics-delete
-@cindex -funix-intrinsics-hide option
-@cindex options, -funix-intrinsics-hide
-@item -funix-intrinsics-hide
-@cindex -funix-intrinsics-disable option
-@cindex options, -funix-intrinsics-disable
-@item -funix-intrinsics-disable
-@cindex -funix-intrinsics-enable option
-@cindex options, -funix-intrinsics-enable
-@item -funix-intrinsics-enable
-@cindex UNIX intrinsics
-@cindex intrinsics, UNIX
-Specify status of UNIX intrinsics.
-@option{-funix-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -fvxt-intrinsics-delete option
-@cindex options, -fvxt-intrinsics-delete
-@item -fvxt-intrinsics-delete
-@cindex -fvxt-intrinsics-hide option
-@cindex options, -fvxt-intrinsics-hide
-@item -fvxt-intrinsics-hide
-@cindex -fvxt-intrinsics-disable option
-@cindex options, -fvxt-intrinsics-disable
-@item -fvxt-intrinsics-disable
-@cindex -fvxt-intrinsics-enable option
-@cindex options, -fvxt-intrinsics-enable
-@item -fvxt-intrinsics-enable
-@cindex VXT intrinsics
-@cindex intrinsics, VXT
-Specify status of VXT intrinsics.
-@option{-fvxt-intrinsics-enable} is the default.
-@xref{Intrinsic Groups}.
-
-@cindex -ffixed-line-length-@var{n} option
-@cindex options, -ffixed-line-length-@var{n}
-@item -ffixed-line-length-@var{n}
-@cindex source file format
-@cindex lines, length
-@cindex length of source lines
-@cindex fixed form
-@cindex limits, lengths of source lines
-Set column after which characters are ignored in typical fixed-form
-lines in the source file, and through which spaces are assumed (as
-if padded to that length) after the ends of short fixed-form lines.
-
-@cindex card image
-@cindex extended-source option
-Popular values for @var{n} include 72 (the
-standard and the default), 80 (card image), and 132 (corresponds
-to ``extended-source'' options in some popular compilers).
-@var{n} may be @samp{none}, meaning that the entire line is meaningful
-and that continued character constants never have implicit spaces appended
-to them to fill out the line.
-@option{-ffixed-line-length-0} means the same thing as
-@option{-ffixed-line-length-none}.
-
-@xref{Source Form}, for more information.
-@end table
-
-@node Warning Options
-@section Options to Request or Suppress Warnings
-@cindex options, warnings
-@cindex warnings, suppressing
-@cindex messages, warning
-@cindex suppressing warnings
-
-Warnings are diagnostic messages that report constructions which
-are not inherently erroneous but which are risky or suggest there
-might have been an error.
-
-You can request many specific warnings with options beginning @option{-W},
-for example @option{-Wimplicit} to request warnings on implicit
-declarations. Each of these specific warning options also has a
-negative form beginning @option{-Wno-} to turn off warnings;
-for example, @option{-Wno-implicit}. This manual lists only one of the
-two forms, whichever is not the default.
-
-These options control the amount and kinds of warnings produced by GNU
-Fortran:
-
-@table @gcctabopt
-@cindex syntax checking
-@cindex -fsyntax-only option
-@cindex options, -fsyntax-only
-@item -fsyntax-only
-Check the code for syntax errors, but don't do anything beyond that.
-
-@cindex -pedantic option
-@cindex options, -pedantic
-@item -pedantic
-Issue warnings for uses of extensions to ANSI FORTRAN 77.
-@option{-pedantic} also applies to C-language constructs where they
-occur in GNU Fortran source files, such as use of @samp{\e} in a
-character constant within a directive like @samp{#include}.
-
-Valid ANSI FORTRAN 77 programs should compile properly with or without
-this option.
-However, without this option, certain GNU extensions and traditional
-Fortran features are supported as well.
-With this option, many of them are rejected.
-
-Some users try to use @option{-pedantic} to check programs for strict ANSI
-conformance.
-They soon find that it does not do quite what they want---it finds some
-non-ANSI practices, but not all.
-However, improvements to @command{g77} in this area are welcome.
-
-@cindex -pedantic-errors option
-@cindex options, -pedantic-errors
-@item -pedantic-errors
-Like @option{-pedantic}, except that errors are produced rather than
-warnings.
-
-@cindex -fpedantic option
-@cindex options, -fpedantic
-@item -fpedantic
-Like @option{-pedantic}, but applies only to Fortran constructs.
-
-@cindex -w option
-@cindex options, -w
-@item -w
-Inhibit all warning messages.
-
-@cindex -Wno-globals option
-@cindex options, -Wno-globals
-@item -Wno-globals
-@cindex global names, warning
-@cindex warnings, global names
-Inhibit warnings about use of a name as both a global name
-(a subroutine, function, or block data program unit, or a
-common block) and implicitly as the name of an intrinsic
-in a source file.
-
-Also inhibit warnings about inconsistent invocations and/or
-definitions of global procedures (function and subroutines).
-Such inconsistencies include different numbers of arguments
-and different types of arguments.
-
-@cindex -Wimplicit option
-@cindex options, -Wimplicit
-@item -Wimplicit
-@cindex implicit declaration, warning
-@cindex warnings, implicit declaration
-@cindex -u option
-@cindex /WARNINGS=DECLARATIONS switch
-@cindex IMPLICIT NONE, similar effect
-@cindex effecting IMPLICIT NONE
-Warn whenever a variable, array, or function is implicitly
-declared.
-Has an effect similar to using the @code{IMPLICIT NONE} statement
-in every program unit.
-(Some Fortran compilers provide this feature by an option
-named @option{-u} or @samp{/WARNINGS=DECLARATIONS}.)
-
-@cindex -Wunused option
-@cindex options, -Wunused
-@item -Wunused
-@cindex unused variables
-@cindex variables, unused
-Warn whenever a variable is unused aside from its declaration.
-
-@cindex -Wuninitialized option
-@cindex options, -Wuninitialized
-@item -Wuninitialized
-@cindex uninitialized variables
-@cindex variables, uninitialized
-Warn whenever an automatic variable is used without first being initialized.
-
-These warnings are possible only in optimizing compilation,
-because they require data-flow information that is computed only
-when optimizing. If you don't specify @option{-O}, you simply won't
-get these warnings.
-
-These warnings occur only for variables that are candidates for
-register allocation. Therefore, they do not occur for a variable
-@c that is declared @code{VOLATILE}, or
-whose address is taken, or whose size
-is other than 1, 2, 4 or 8 bytes. Also, they do not occur for
-arrays, even when they are in registers.
-
-Note that there might be no warning about a variable that is used only
-to compute a value that itself is never used, because such
-computations may be deleted by data-flow analysis before the warnings
-are printed.
-
-These warnings are made optional because GNU Fortran is not smart
-enough to see all the reasons why the code might be correct
-despite appearing to have an error. Here is one example of how
-this can happen:
-
-@example
-SUBROUTINE DISPAT(J)
-IF (J.EQ.1) I=1
-IF (J.EQ.2) I=4
-IF (J.EQ.3) I=5
-CALL FOO(I)
-END
-@end example
-
-@noindent
-If the value of @code{J} is always 1, 2 or 3, then @code{I} is
-always initialized, but GNU Fortran doesn't know this. Here is
-another common case:
-
-@example
-SUBROUTINE MAYBE(FLAG)
-LOGICAL FLAG
-IF (FLAG) VALUE = 9.4
-@dots{}
-IF (FLAG) PRINT *, VALUE
-END
-@end example
-
-@noindent
-This has no bug because @code{VALUE} is used only if it is set.
-
-@cindex -Wall option
-@cindex options, -Wall
-@item -Wall
-@cindex all warnings
-@cindex warnings, all
-The @option{-Wunused} and @option{-Wuninitialized} options combined.
-These are all the
-options which pertain to usage that we recommend avoiding and that we
-believe is easy to avoid.
-(As more warnings are added to @command{g77} some might
-be added to the list enabled by @option{-Wall}.)
-@end table
-
-The remaining @option{-W@dots{}} options are not implied by @option{-Wall}
-because they warn about constructions that we consider reasonable to
-use, on occasion, in clean programs.
-
-@table @gcctabopt
-@c @item -W
-@c Print extra warning messages for these events:
-@c
-@c @itemize @bullet
-@c @item
-@c If @option{-Wall} or @option{-Wunused} is also specified, warn about unused
-@c arguments.
-@c
-@c @end itemize
-@c
-@cindex -Wsurprising option
-@cindex options, -Wsurprising
-@item -Wsurprising
-Warn about ``suspicious'' constructs that are interpreted
-by the compiler in a way that might well be surprising to
-someone reading the code.
-These differences can result in subtle, compiler-dependent
-(even machine-dependent) behavioral differences.
-The constructs warned about include:
-
-@itemize @bullet
-@item
-Expressions having two arithmetic operators in a row, such
-as @samp{X*-Y}.
-Such a construct is nonstandard, and can produce
-unexpected results in more complicated situations such
-as @samp{X**-Y*Z}.
-@command{g77} along with many other compilers, interprets
-this example differently than many programmers, and a few
-other compilers.
-Specifically, @command{g77} interprets @samp{X**-Y*Z} as
-@samp{(X**(-Y))*Z}, while others might think it should
-be interpreted as @samp{X**(-(Y*Z))}.
-
-A revealing example is the constant expression @samp{2**-2*1.},
-which @command{g77} evaluates to .25, while others might evaluate
-it to 0., the difference resulting from the way precedence affects
-type promotion.
-
-(The @option{-fpedantic} option also warns about expressions
-having two arithmetic operators in a row.)
-
-@item
-Expressions with a unary minus followed by an operand and then
-a binary operator other than plus or minus.
-For example, @samp{-2**2} produces a warning, because
-the precedence is @samp{-(2**2)}, yielding -4, not
-@samp{(-2)**2}, which yields 4, and which might represent
-what a programmer expects.
-
-An example of an expression producing different results
-in a surprising way is @samp{-I*S}, where @var{I} holds
-the value @samp{-2147483648} and @var{S} holds @samp{0.5}.
-On many systems, negating @var{I} results in the same
-value, not a positive number, because it is already the
-lower bound of what an @code{INTEGER(KIND=1)} variable can hold.
-So, the expression evaluates to a positive number, while
-the ``expected'' interpretation, @samp{(-I)*S}, would
-evaluate to a negative number.
-
-Even cases such as @samp{-I*J} produce warnings,
-even though, in most configurations and situations,
-there is no computational difference between the
-results of the two interpretations---the purpose
-of this warning is to warn about differing interpretations
-and encourage a better style of coding, not to identify
-only those places where bugs might exist in the user's
-code.
-
-@cindex DO statement
-@cindex statements, DO
-@item
-@code{DO} loops with @code{DO} variables that are not
-of integral type---that is, using @code{REAL}
-variables as loop control variables.
-Although such loops can be written to work in the
-``obvious'' way, the way @command{g77} is required by the
-Fortran standard to interpret such code is likely to
-be quite different from the way many programmers expect.
-(This is true of all @code{DO} loops, but the differences
-are pronounced for non-integral loop control variables.)
-
-@xref{Loops}, for more information.
-@end itemize
-
-@cindex -Werror option
-@cindex options, -Werror
-@item -Werror
-Make all warnings into errors.
-
-@cindex -W option
-@cindex options, -W
-@item -W
-@cindex extra warnings
-@cindex warnings, extra
-Turns on ``extra warnings'' and, if optimization is specified
-via @option{-O}, the @option{-Wuninitialized} option.
-(This might change in future versions of @command{g77}
-
-``Extra warnings'' are issued for:
-
-@itemize @bullet
-@item
-@cindex unused parameters
-@cindex parameters, unused
-@cindex unused arguments
-@cindex arguments, unused
-@cindex unused dummies
-@cindex dummies, unused
-Unused parameters to a procedure (when @option{-Wunused} also is
-specified).
-
-@item
-@cindex overflow
-Overflows involving floating-point constants (not available
-for certain configurations).
-@end itemize
-@end table
-
-@xref{Warning Options,,Options to Request or Suppress Warnings,
-gcc,Using the GNU Compiler Collection (GCC)}, for information on more
-options offered
-by the GBE shared by @command{g77} @command{gcc} and other GNU compilers.
-
-Some of these have no effect when compiling programs written in Fortran:
-
-@table @gcctabopt
-@cindex -Wcomment option
-@cindex options, -Wcomment
-@item -Wcomment
-@cindex -Wformat option
-@cindex options, -Wformat
-@item -Wformat
-@cindex -Wparentheses option
-@cindex options, -Wparentheses
-@item -Wparentheses
-@cindex -Wswitch option
-@cindex options, -Wswitch
-@item -Wswitch
-@cindex -Wtraditional option
-@cindex options, -Wtraditional
-@item -Wtraditional
-@cindex -Wshadow option
-@cindex options, -Wshadow
-@item -Wshadow
-@cindex -Wid-clash-@var{len} option
-@cindex options, -Wid-clash-@var{len}
-@item -Wid-clash-@var{len}
-@cindex -Wlarger-than-@var{len} option
-@cindex options, -Wlarger-than-@var{len}
-@item -Wlarger-than-@var{len}
-@cindex -Wconversion option
-@cindex options, -Wconversion
-@item -Wconversion
-@cindex -Waggregate-return option
-@cindex options, -Waggregate-return
-@item -Waggregate-return
-@cindex -Wredundant-decls option
-@cindex options, -Wredundant-decls
-@item -Wredundant-decls
-@cindex unsupported warnings
-@cindex warnings, unsupported
-These options all could have some relevant meaning for
-GNU Fortran programs, but are not yet supported.
-@end table
-
-@node Debugging Options
-@section Options for Debugging Your Program or GNU Fortran
-@cindex options, debugging
-@cindex debugging information options
-
-GNU Fortran has various special options that are used for debugging
-either your program or @command{g77}
-
-@table @gcctabopt
-@cindex -g option
-@cindex options, -g
-@item -g
-Produce debugging information in the operating system's native format
-(stabs, COFF, XCOFF, or DWARF). GDB can work with this debugging
-information.
-
-A sample debugging session looks like this (note the use of the breakpoint):
-@smallexample
-$ cat gdb.f
- PROGRAM PROG
- DIMENSION A(10)
- DATA A /1.,2.,3.,4.,5.,6.,7.,8.,9.,10./
- A(5) = 4.
- PRINT*,A
- END
-$ g77 -g -O gdb.f
-$ gdb a.out
-...
-(gdb) break MAIN__
-Breakpoint 1 at 0x8048e96: file gdb.f, line 4.
-(gdb) run
-Starting program: /home/toon/g77-bugs/./a.out
-Breakpoint 1, MAIN__ () at gdb.f:4
-4 A(5) = 4.
-Current language: auto; currently fortran
-(gdb) print a(5)
-$1 = 5
-(gdb) step
-5 PRINT*,A
-(gdb) print a(5)
-$2 = 4
-...
-@end smallexample
-One could also add the setting of the breakpoint and the first run command
-to the file @file{.gdbinit} in the current directory, to simplify the debugging
-session.
-@end table
-
-@xref{Debugging Options,,Options for Debugging Your Program or GCC,
-gcc,Using the GNU Compiler Collection (GCC)}, for more information on
-debugging options.
-
-@node Optimize Options
-@section Options That Control Optimization
-@cindex optimize options
-@cindex options, optimization
-
-Most Fortran users will want to use no optimization when
-developing and testing programs, and use @option{-O} or @option{-O2} when
-compiling programs for late-cycle testing and for production use.
-However, note that certain diagnostics---such as for uninitialized
-variables---depend on the flow analysis done by @option{-O}, i.e.@: you
-must use @option{-O} or @option{-O2} to get such diagnostics.
-
-The following flags have particular applicability when
-compiling Fortran programs:
-
-@table @gcctabopt
-@cindex -malign-double option
-@cindex options, -malign-double
-@item -malign-double
-(Intel x86 architecture only.)
-
-Noticeably improves performance of @command{g77} programs making
-heavy use of @code{REAL(KIND=2)} (@code{DOUBLE PRECISION}) data
-on some systems.
-In particular, systems using Pentium, Pentium Pro, 586, and
-686 implementations
-of the i386 architecture execute programs faster when
-@code{REAL(KIND=2)} (@code{DOUBLE PRECISION}) data are
-aligned on 64-bit boundaries
-in memory.
-
-This option can, at least, make benchmark results more consistent
-across various system configurations, versions of the program,
-and data sets.
-
-@emph{Note:} The warning in the @command{gcc} documentation about
-this option does not apply, generally speaking, to Fortran
-code compiled by @command{g77}
-
-@xref{Aligned Data}, for more information on alignment issues.
-
-@emph{Also also note:} The negative form of @option{-malign-double}
-is @option{-mno-align-double}, not @option{-benign-double}.
-
-@cindex -ffloat-store option
-@cindex options, -ffloat-store
-@item -ffloat-store
-@cindex IEEE 754 conformance
-@cindex conformance, IEEE 754
-@cindex floating-point, precision
-Might help a Fortran program that depends on exact IEEE conformance on
-some machines, but might slow down a program that doesn't.
-
-This option is effective when the floating-point unit is set to work in
-IEEE 854 `extended precision'---as it typically is on x86 and m68k GNU
-systems---rather than IEEE 754 double precision. @option{-ffloat-store}
-tries to remove the extra precision by spilling data from floating-point
-registers into memory and this typically involves a big performance
-hit. However, it doesn't affect intermediate results, so that it is
-only partially effective. `Excess precision' is avoided in code like:
-@smallexample
-a = b + c
-d = a * e
-@end smallexample
-but not in code like:
-@smallexample
- d = (b + c) * e
-@end smallexample
-
-For another, potentially better, way of controlling the precision,
-see @ref{Floating-point precision}.
-
-@cindex -fforce-mem option
-@cindex options, -fforce-mem
-@item -fforce-mem
-@cindex -fforce-addr option
-@cindex options, -fforce-addr
-@item -fforce-addr
-@cindex loops, speeding up
-@cindex speed, of loops
-Might improve optimization of loops.
-
-@cindex -fno-inline option
-@cindex options, -fno-inline
-@item -fno-inline
-@cindex in-line code
-@cindex compilation, in-line
-@c DL: Only relevant for -O3? TM: No, statement functions are
-@c inlined even at -O1.
-Don't compile statement functions inline.
-Might reduce the size of a program unit---which might be at
-expense of some speed (though it should compile faster).
-Note that if you are not optimizing, no functions can be expanded inline.
-
-@cindex -ffast-math option
-@cindex options, -ffast-math
-@item -ffast-math
-@cindex IEEE 754 conformance
-@cindex conformance, IEEE 754
-Might allow some programs designed to not be too dependent
-on IEEE behavior for floating-point to run faster, or die trying.
-Sets @option{-funsafe-math-optimizations}, and
-@option{-fno-trapping-math}.
-
-@cindex -funsafe-math-optimizations option
-@cindex options, -funsafe-math-optimizations
-@item -funsafe-math-optimizations
-Allow optimizations that may be give incorrect results
-for certain IEEE inputs.
-
-@cindex -fno-trapping-math option
-@cindex options, -fno-trapping-math
-@item -fno-trapping-math
-Allow the compiler to assume that floating-point arithmetic
-will not generate traps on any inputs. This is useful, for
-example, when running a program using IEEE "non-stop"
-floating-point arithmetic.
-
-@cindex -fstrength-reduce option
-@cindex options, -fstrength-reduce
-@item -fstrength-reduce
-@cindex loops, speeding up
-@cindex speed, of loops
-@c DL: normally defaulted?
-Might make some loops run faster.
-
-@cindex -frerun-cse-after-loop option
-@cindex options, -frerun-cse-after-loop
-@item -frerun-cse-after-loop
-@cindex -fexpensive-optimizations option
-@cindex options, -fexpensive-optimizations
-@c DL: This is -O2?
-@item -fexpensive-optimizations
-@cindex -fdelayed-branch option
-@cindex options, -fdelayed-branch
-@item -fdelayed-branch
-@cindex -fschedule-insns option
-@cindex options, -fschedule-insns
-@item -fschedule-insns
-@cindex -fschedule-insns2 option
-@cindex options, -fschedule-insns2
-@item -fschedule-insns2
-@cindex -fcaller-saves option
-@cindex options, -fcaller-saves
-@item -fcaller-saves
-Might improve performance on some code.
-
-@cindex -funroll-loops option
-@cindex options, -funroll-loops
-@item -funroll-loops
-@cindex loops, unrolling
-@cindex unrolling loops
-@cindex loops, optimizing
-@cindex indexed (iterative) @code{DO}
-@cindex iterative @code{DO}
-@c DL: fixme: Craig doesn't like `indexed' but f95 doesn't seem to
-@c provide a suitable term
-@c CB: I've decided on `iterative', for the time being, and changed
-@c my previous, rather bizarre, use of `imperative' to that
-@c (though `precomputed-trip' would be a more precise adjective)
-Typically improves performance on code using iterative @code{DO} loops by
-unrolling them and is probably generally appropriate for Fortran, though
-it is not turned on at any optimization level.
-Note that outer loop unrolling isn't done specifically; decisions about
-whether to unroll a loop are made on the basis of its instruction count.
-
-@c DL: Fixme: This should obviously go somewhere else...
-Also, no `loop discovery'@footnote{@dfn{loop discovery} refers to the
-process by which a compiler, or indeed any reader of a program,
-determines which portions of the program are more likely to be executed
-repeatedly as it is being run. Such discovery typically is done early
-when compiling using optimization techniques, so the ``discovered''
-loops get more attention---and more run-time resources, such as
-registers---from the compiler. It is easy to ``discover'' loops that are
-constructed out of looping constructs in the language
-(such as Fortran's @code{DO}). For some programs, ``discovering'' loops
-constructed out of lower-level constructs (such as @code{IF} and
-@code{GOTO}) can lead to generation of more optimal code
-than otherwise.} is done, so only loops written with @code{DO}
-benefit from loop optimizations, including---but not limited
-to---unrolling. Loops written with @code{IF} and @code{GOTO} are not
-currently recognized as such. This option unrolls only iterative
-@code{DO} loops, not @code{DO WHILE} loops.
-
-@cindex -funroll-all-loops option
-@cindex options, -funroll-all-loops
-@cindex DO WHILE
-@item -funroll-all-loops
-@c DL: Check my understanding of -funroll-all-loops v. -funroll-loops is correct.
-Probably improves performance on code using @code{DO WHILE} loops by
-unrolling them in addition to iterative @code{DO} loops. In the absence
-of @code{DO WHILE}, this option is equivalent to @option{-funroll-loops}
-but possibly slower.
-
-@item -fno-move-all-movables
-@cindex -fno-move-all-movables option
-@cindex options, -fno-move-all-movables
-@item -fno-reduce-all-givs
-@cindex -fno-reduce-all-givs option
-@cindex options, -fno-reduce-all-givs
-@item -fno-rerun-loop-opt
-@cindex -fno-rerun-loop-opt option
-@cindex options, -fno-rerun-loop-opt
-In general, the optimizations enabled with these options will lead to
-faster code being generated by GNU Fortran; hence they are enabled by default
-when issuing the @command{g77} command.
-
-@option{-fmove-all-movables} and @option{-freduce-all-givs} will enable
-loop optimization to move all loop-invariant index computations in nested
-loops over multi-rank array dummy arguments out of these loops.
-
-@option{-frerun-loop-opt} will move offset calculations resulting
-from the fact that Fortran arrays by default have a lower bound of 1
-out of the loops.
-
-These three options are intended to be removed someday, once
-loop optimization is sufficiently advanced to perform all those
-transformations without help from these options.
-@end table
-
-@xref{Optimize Options,,Options That Control Optimization,
-gcc,Using the GNU Compiler Collection (GCC)}, for more information on options
-to optimize the generated machine code.
-
-@node Preprocessor Options
-@section Options Controlling the Preprocessor
-@cindex preprocessor options
-@cindex options, preprocessor
-@cindex cpp program
-@cindex programs, cpp
-
-These options control the C preprocessor, which is run on each C source
-file before actual compilation.
-
-@xref{Preprocessor Options,,Options Controlling the Preprocessor,
-gcc,Using the GNU Compiler Collection (GCC)}, for information on C
-preprocessor options.
-
-@cindex INCLUDE directive
-@cindex directive, INCLUDE
-Some of these options also affect how @command{g77} processes the
-@code{INCLUDE} directive.
-Since this directive is processed even when preprocessing
-is not requested, it is not described in this section.
-@xref{Directory Options,,Options for Directory Search}, for
-information on how @command{g77} processes the @code{INCLUDE} directive.
-
-However, the @code{INCLUDE} directive does not apply
-preprocessing to the contents of the included file itself.
-
-Therefore, any file that contains preprocessor directives
-(such as @code{#include}, @code{#define}, and @code{#if})
-must be included via the @code{#include} directive, not
-via the @code{INCLUDE} directive.
-Therefore, any file containing preprocessor directives,
-if included, is necessarily included by a file that itself
-contains preprocessor directives.
-
-@node Directory Options
-@section Options for Directory Search
-@cindex directory, options
-@cindex options, directory search
-@cindex search path
-
-These options affect how the @command{cpp} preprocessor searches
-for files specified via the @code{#include} directive.
-Therefore, when compiling Fortran programs, they are meaningful
-when the preprocessor is used.
-
-@cindex INCLUDE directive
-@cindex directive, INCLUDE
-Some of these options also affect how @command{g77} searches
-for files specified via the @code{INCLUDE} directive,
-although files included by that directive are not,
-themselves, preprocessed.
-These options are:
-
-@table @gcctabopt
-@cindex -I- option
-@cindex options, -I-
-@item -I-
-@cindex -Idir option
-@cindex options, -Idir
-@item -I@var{dir}
-@cindex directory, search paths for inclusion
-@cindex inclusion, directory search paths for
-@cindex search paths, for included files
-@cindex paths, search
-These affect interpretation of the @code{INCLUDE} directive
-(as well as of the @code{#include} directive of the @command{cpp}
-preprocessor).
-
-Note that @option{-I@var{dir}} must be specified @emph{without} any
-spaces between @option{-I} and the directory name---that is,
-@option{-Ifoo/bar} is valid, but @option{-I foo/bar}
-is rejected by the @command{g77} compiler (though the preprocessor supports
-the latter form).
-@c this is due to toplev.c's inflexible option processing
-Also note that the general behavior of @option{-I} and
-@code{INCLUDE} is pretty much the same as of @option{-I} with
-@code{#include} in the @command{cpp} preprocessor, with regard to
-looking for @file{header.gcc} files and other such things.
-
-@xref{Directory Options,,Options for Directory Search,
-gcc,Using the GNU Compiler Collection (GCC)}, for information on the
-@option{-I} option.
-@end table
-
-@node Code Gen Options
-@section Options for Code Generation Conventions
-@cindex code generation, conventions
-@cindex options, code generation
-@cindex run-time, options
-
-These machine-independent options control the interface conventions
-used in code generation.
-
-Most of them have both positive and negative forms; the negative form
-of @option{-ffoo} would be @option{-fno-foo}. In the table below, only
-one of the forms is listed---the one which is not the default. You
-can figure out the other form by either removing @option{no-} or adding
-it.
-
-@table @gcctabopt
-@cindex -fno-automatic option
-@cindex options, -fno-automatic
-@item -fno-automatic
-@cindex SAVE statement
-@cindex statements, SAVE
-Treat each program unit as if the @code{SAVE} statement was specified
-for every local variable and array referenced in it.
-Does not affect common blocks.
-(Some Fortran compilers provide this option under
-the name @option{-static}.)
-
-@cindex -finit-local-zero option
-@cindex options, -finit-local-zero
-@item -finit-local-zero
-@cindex DATA statement
-@cindex statements, DATA
-@cindex initialization, of local variables
-@cindex variables, initialization of
-@cindex uninitialized variables
-@cindex variables, uninitialized
-Specify that variables and arrays that are local to a program unit
-(not in a common block and not passed as an argument) are to be initialized
-to binary zeros.
-
-Since there is a run-time penalty for initialization of variables
-that are not given the @code{SAVE} attribute, it might be a
-good idea to also use @option{-fno-automatic} with @option{-finit-local-zero}.
-
-@cindex -fno-f2c option
-@cindex options, -fno-f2c
-@item -fno-f2c
-@cindex @command{f2c} compatibility
-@cindex compatibility, @command{f2c}
-Do not generate code designed to be compatible with code generated
-by @command{f2c} use the GNU calling conventions instead.
-
-The @command{f2c} calling conventions require functions that return
-type @code{REAL(KIND=1)} to actually return the C type @code{double},
-and functions that return type @code{COMPLEX} to return the
-values via an extra argument in the calling sequence that points
-to where to store the return value.
-Under the GNU calling conventions, such functions simply return
-their results as they would in GNU C---@code{REAL(KIND=1)} functions
-return the C type @code{float}, and @code{COMPLEX} functions
-return the GNU C type @code{complex} (or its @code{struct}
-equivalent).
-
-This does not affect the generation of code that interfaces with the
-@code{libg2c} library.
-
-However, because the @code{libg2c} library uses @command{f2c}
-calling conventions, @command{g77} rejects attempts to pass
-intrinsics implemented by routines in this library as actual
-arguments when @option{-fno-f2c} is used, to avoid bugs when
-they are actually called by code expecting the GNU calling
-conventions to work.
-
-For example, @samp{INTRINSIC ABS;CALL FOO(ABS)} is
-rejected when @option{-fno-f2c} is in force.
-(Future versions of the @command{g77} run-time library might
-offer routines that provide GNU-callable versions of the
-routines that implement the @command{f2c} intrinsics
-that may be passed as actual arguments, so that
-valid programs need not be rejected when @option{-fno-f2c}
-is used.)
-
-@strong{Caution:} If @option{-fno-f2c} is used when compiling any
-source file used in a program, it must be used when compiling
-@emph{all} Fortran source files used in that program.
-
-@c seems kinda dumb to tell people about an option they can't use -- jcb
-@c then again, we want users building future-compatible libraries with it.
-@cindex -ff2c-library option
-@cindex options, -ff2c-library
-@item -ff2c-library
-Specify that use of @code{libg2c} (or the original @code{libf2c})
-is required.
-This is the default for the current version of @command{g77}
-
-Currently it is not
-valid to specify @option{-fno-f2c-library}.
-This option is provided so users can specify it in shell
-scripts that build programs and libraries that require the
-@code{libf2c} library, even when being compiled by future
-versions of @command{g77} that might otherwise default to
-generating code for an incompatible library.
-
-@cindex -fno-underscoring option
-@cindex options, -fno-underscoring
-@item -fno-underscoring
-@cindex underscore
-@cindex symbol names, underscores
-@cindex transforming symbol names
-@cindex symbol names, transforming
-Do not transform names of entities specified in the Fortran
-source file by appending underscores to them.
-
-With @option{-funderscoring} in effect, @command{g77} appends two underscores
-to names with underscores and one underscore to external names with
-no underscores. (@command{g77} also appends two underscores to internal
-names with underscores to avoid naming collisions with external names.
-The @option{-fno-second-underscore} option disables appending of the
-second underscore in all cases.)
-
-This is done to ensure compatibility with code produced by many
-UNIX Fortran compilers, including @command{f2c} which perform the
-same transformations.
-
-Use of @option{-fno-underscoring} is not recommended unless you are
-experimenting with issues such as integration of (GNU) Fortran into
-existing system environments (vis-a-vis existing libraries, tools, and
-so on).
-
-For example, with @option{-funderscoring}, and assuming other defaults like
-@option{-fcase-lower} and that @samp{j()} and @samp{max_count()} are
-external functions while @samp{my_var} and @samp{lvar} are local variables,
-a statement like
-
-@smallexample
-I = J() + MAX_COUNT (MY_VAR, LVAR)
-@end smallexample
-
-@noindent
-is implemented as something akin to:
-
-@smallexample
-i = j_() + max_count__(&my_var__, &lvar);
-@end smallexample
-
-With @option{-fno-underscoring}, the same statement is implemented as:
-
-@smallexample
-i = j() + max_count(&my_var, &lvar);
-@end smallexample
-
-Use of @option{-fno-underscoring} allows direct specification of
-user-defined names while debugging and when interfacing @command{g77}
-code with other languages.
-
-Note that just because the names match does @emph{not} mean that the
-interface implemented by @command{g77} for an external name matches the
-interface implemented by some other language for that same name.
-That is, getting code produced by @command{g77} to link to code produced
-by some other compiler using this or any other method can be only a
-small part of the overall solution---getting the code generated by
-both compilers to agree on issues other than naming can require
-significant effort, and, unlike naming disagreements, linkers normally
-cannot detect disagreements in these other areas.
-
-Also, note that with @option{-fno-underscoring}, the lack of appended
-underscores introduces the very real possibility that a user-defined
-external name will conflict with a name in a system library, which
-could make finding unresolved-reference bugs quite difficult in some
-cases---they might occur at program run time, and show up only as
-buggy behavior at run time.
-
-In future versions of @command{g77} we hope to improve naming and linking
-issues so that debugging always involves using the names as they appear
-in the source, even if the names as seen by the linker are mangled to
-prevent accidental linking between procedures with incompatible
-interfaces.
-
-@cindex -fno-second-underscore option
-@cindex options, -fno-second-underscore
-@item -fno-second-underscore
-@cindex underscore
-@cindex symbol names, underscores
-@cindex transforming symbol names
-@cindex symbol names, transforming
-Do not append a second underscore to names of entities specified
-in the Fortran source file.
-
-This option has no effect if @option{-fno-underscoring} is
-in effect.
-
-Otherwise, with this option, an external name such as @samp{MAX_COUNT}
-is implemented as a reference to the link-time external symbol
-@samp{max_count_}, instead of @samp{max_count__}.
-
-@cindex -fno-ident option
-@cindex options, -fno-ident
-@item -fno-ident
-Ignore the @samp{#ident} directive.
-
-@cindex -fzeros option
-@cindex options, -fzeros
-@item -fzeros
-Treat initial values of zero as if they were any other value.
-
-As of version 0.5.18, @command{g77} normally treats @code{DATA} and
-other statements that are used to specify initial values of zero
-for variables and arrays as if no values were actually specified,
-in the sense that no diagnostics regarding multiple initializations
-are produced.
-
-This is done to speed up compiling of programs that initialize
-large arrays to zeros.
-
-Use @option{-fzeros} to revert to the simpler, slower behavior
-that can catch multiple initializations by keeping track of
-all initializations, zero or otherwise.
-
-@emph{Caution:} Future versions of @command{g77} might disregard this option
-(and its negative form, the default) or interpret it somewhat
-differently.
-The interpretation changes will affect only non-standard
-programs; standard-conforming programs should not be affected.
-
-@cindex -femulate-complex option
-@cindex options, -femulate-complex
-@item -femulate-complex
-Implement @code{COMPLEX} arithmetic via emulation,
-instead of using the facilities of
-the @command{gcc} back end that provide direct support of
-@code{complex} arithmetic.
-
-(@command{gcc} had some bugs in its back-end support
-for @code{complex} arithmetic, due primarily to the support not being
-completed as of version 2.8.1 and @code{egcs} 1.1.2.)
-
-Use @option{-femulate-complex} if you suspect code-generation bugs,
-or experience compiler crashes,
-that might result from @command{g77} using the @code{COMPLEX} support
-in the @command{gcc} back end.
-If using that option fixes the bugs or crashes you are seeing,
-that indicates a likely @command{g77} bugs
-(though, all compiler crashes are considered bugs),
-so, please report it.
-(Note that the known bugs, now believed fixed, produced compiler crashes
-rather than causing the generation of incorrect code.)
-
-Use of this option should not affect how Fortran code compiled
-by @command{g77} works in terms of its interfaces to other code,
-e.g. that compiled by @command{f2c}
-
-As of GCC version 3.0, this option is not necessary anymore.
-
-@emph{Caution:} Future versions of @command{g77} might ignore both forms
-of this option.
-
-@cindex -falias-check option
-@cindex options, -falias-check
-@cindex -fargument-alias option
-@cindex options, -fargument-alias
-@cindex -fargument-noalias option
-@cindex options, -fargument-noalias
-@cindex -fno-argument-noalias-global option
-@cindex options, -fno-argument-noalias-global
-@item -falias-check
-@item -fargument-alias
-@item -fargument-noalias
-@item -fno-argument-noalias-global
-@emph{Version info:}
-These options are not supported by
-versions of @command{g77} based on @command{gcc} version 2.8.
-
-These options specify to what degree aliasing
-(overlap)
-is permitted between
-arguments (passed as pointers) and @code{COMMON} (external, or
-public) storage.
-
-The default for Fortran code, as mandated by the FORTRAN 77 and
-Fortran 90 standards, is @option{-fargument-noalias-global}.
-The default for code written in the C language family is
-@option{-fargument-alias}.
-
-Note that, on some systems, compiling with @option{-fforce-addr} in
-effect can produce more optimal code when the default aliasing
-options are in effect (and when optimization is enabled).
-
-@xref{Aliasing Assumed To Work}, for detailed information on the implications
-of compiling Fortran code that depends on the ability to alias dummy
-arguments.
-
-@cindex -fno-globals option
-@cindex options, -fno-globals
-@item -fno-globals
-@cindex global names, warning
-@cindex warnings, global names
-@cindex in-line code
-@cindex compilation, in-line
-Disable diagnostics about inter-procedural
-analysis problems, such as disagreements about the
-type of a function or a procedure's argument,
-that might cause a compiler crash when attempting
-to inline a reference to a procedure within a
-program unit.
-(The diagnostics themselves are still produced, but
-as warnings, unless @option{-Wno-globals} is specified,
-in which case no relevant diagnostics are produced.)
-
-Further, this option disables such inlining, to
-avoid compiler crashes resulting from incorrect
-code that would otherwise be diagnosed.
-
-As such, this option might be quite useful when
-compiling existing, ``working'' code that happens
-to have a few bugs that do not generally show themselves,
-but which @command{g77} diagnoses.
-
-Use of this option therefore has the effect of
-instructing @command{g77} to behave more like it did
-up through version 0.5.19.1, when it paid little or
-no attention to disagreements between program units
-about a procedure's type and argument information,
-and when it performed no inlining of procedures
-(except statement functions).
-
-Without this option, @command{g77} defaults to performing
-the potentially inlining procedures as it started doing
-in version 0.5.20, but as of version 0.5.21, it also
-diagnoses disagreements that might cause such inlining
-to crash the compiler as (fatal) errors,
-and warns about similar disagreements
-that are currently believed to not
-likely to result in the compiler later crashing
-or producing incorrect code.
-
-@cindex -fflatten-arrays option
-@item -fflatten-arrays
-@cindex array performance
-@cindex arrays, flattening
-Use back end's C-like constructs
-(pointer plus offset)
-instead of its @code{ARRAY_REF} construct
-to handle all array references.
-
-@emph{Note:} This option is not supported.
-It is intended for use only by @command{g77} developers,
-to evaluate code-generation issues.
-It might be removed at any time.
-
-@cindex -fbounds-check option
-@cindex -ffortran-bounds-check option
-@item -fbounds-check
-@itemx -ffortran-bounds-check
-@cindex bounds checking
-@cindex range checking
-@cindex array bounds checking
-@cindex subscript checking
-@cindex substring checking
-@cindex checking subscripts
-@cindex checking substrings
-Enable generation of run-time checks for array subscripts
-and substring start and end points
-against the (locally) declared minimum and maximum values.
-
-The current implementation uses the @code{libf2c}
-library routine @code{s_rnge} to print the diagnostic.
-
-However, whereas @command{f2c} generates a single check per
-reference for a multi-dimensional array, of the computed
-offset against the valid offset range (0 through the size of the array),
-@command{g77} generates a single check per @emph{subscript} expression.
-This catches some cases of potential bugs that @command{f2c} does not,
-such as references to below the beginning of an assumed-size array.
-
-@command{g77} also generates checks for @code{CHARACTER} substring references,
-something @command{f2c} currently does not do.
-
-Use the new @option{-ffortran-bounds-check} option
-to specify bounds-checking for only the Fortran code you are compiling,
-not necessarily for code written in other languages.
-
-@emph{Note:} To provide more detailed information on the offending subscript,
-@command{g77} provides the @code{libg2c} run-time library routine @code{s_rnge}
-with somewhat differently-formatted information.
-Here's a sample diagnostic:
-
-@smallexample
-Subscript out of range on file line 4, procedure rnge.f/bf.
-Attempt to access the -6-th element of variable b[subscript-2-of-2].
-Aborted
-@end smallexample
-
-The above message indicates that the offending source line is
-line 4 of the file @file{rnge.f},
-within the program unit (or statement function) named @samp{bf}.
-The offended array is named @samp{b}.
-The offended array dimension is the second for a two-dimensional array,
-and the offending, computed subscript expression was @samp{-6}.
-
-For a @code{CHARACTER} substring reference, the second line has
-this appearance:
-
-@smallexample
-Attempt to access the 11-th element of variable a[start-substring].
-@end smallexample
-
-This indicates that the offended @code{CHARACTER} variable or array
-is named @samp{a},
-the offended substring position is the starting (leftmost) position,
-and the offending substring expression is @samp{11}.
-
-(Though the verbage of @code{s_rnge} is not ideal
-for the purpose of the @command{g77} compiler,
-the above information should provide adequate diagnostic abilities
-to it users.)
-@end table
-
-@xref{Code Gen Options,,Options for Code Generation Conventions,
-gcc,Using the GNU Compiler Collection (GCC)}, for information on more options
-offered by the GBE
-shared by @command{g77} @command{gcc} and other GNU compilers.
-
-Some of these do @emph{not} work when compiling programs written in Fortran:
-
-@table @gcctabopt
-@cindex -fpcc-struct-return option
-@cindex options, -fpcc-struct-return
-@item -fpcc-struct-return
-@cindex -freg-struct-return option
-@cindex options, -freg-struct-return
-@item -freg-struct-return
-You should not use these except strictly the same way as you
-used them to build the version of @code{libg2c} with which
-you will be linking all code compiled by @command{g77} with the
-same option.
-
-@cindex -fshort-double option
-@cindex options, -fshort-double
-@item -fshort-double
-This probably either has no effect on Fortran programs, or
-makes them act loopy.
-
-@cindex -fno-common option
-@cindex options, -fno-common
-@item -fno-common
-Do not use this when compiling Fortran programs,
-or there will be Trouble.
-
-@cindex -fpack-struct option
-@cindex options, -fpack-struct
-@item -fpack-struct
-This probably will break any calls to the @code{libg2c} library,
-at the very least, even if it is built with the same option.
-@end table
-
-@c man end
-
-@node Environment Variables
-@section Environment Variables Affecting GNU Fortran
-@cindex environment variables
-
-@c man begin ENVIRONMENT
-
-GNU Fortran currently does not make use of any environment
-variables to control its operation above and beyond those
-that affect the operation of @command{gcc}.
-
-@xref{Environment Variables,,Environment Variables Affecting GCC,
-gcc,Using the GNU Compiler Collection (GCC)}, for information on environment
-variables.
-
-@c man end
projects / msp430-gcc.git / blobdiff