egcs/gcc/f/g77.texi

[craig at jcb-sc dot com]

I've just committed this patch.

        tq vm, (burley)


1999-02-18  Craig Burley  <craig@jcb-sc.com>

	* g77.texi: Clarify -fno-globals vs. -Wno-globals.

  
*** g77-e/gcc/f/g77.texi.~1~	Wed Feb 17 11:42:14 1999
--- g77-e/gcc/f/g77.texi	Thu Feb 18 05:54:27 1999
*************** arguments.
*** 3283,3286 ****
--- 3283,3288 ----
  @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
*************** code that would otherwise be diagnosed.
*** 3299,3305 ****
  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 @code{g77} exposes via a
! diagnostic.
  
  Use of this option therefore has the effect of
--- 3301,3306 ----
  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 @code{g77} diagnoses.
  
  Use of this option therefore has the effect of
*************** the potentially inlining procedures as i
*** 3315,3319 ****
  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.
  @end table
  
--- 3316,3324 ----
  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.
  @end table
  
*************** Argument #@var{n} of @var{name} is @dots
*** 15209,15235 ****
  
  These messages all identify disagreements about the
! global procedure named @var{name} among different program
! units (usually including @var{name} itself).
  
! These disagreements, if not diagnosed, could result in a
! compiler crash if the compiler attempted to inline a reference
! to @var{name} within a calling program unit that disagreed
! with the @var{name} program unit regarding whether the
! procedure is a subroutine or function, the type of the
! return value of the procedure (if it is a function), the
! number of arguments the procedure accepts, or the type
! of each argument.
! 
! Such disagreements @emph{should} be fixed in the Fortran
! code itself.
! However, if that is not immediately practical, and the code
! has been working for some time, it is possible it will work
! when compiled by @code{g77} with the @samp{-fno-globals} option.
! 
! The @samp{-fno-globals} option disables these diagnostics, and
! also disables all inlining of references to global procedures
! to avoid compiler crashes.
! The diagnostics are actually produced, but as warnings, unless
! the @samp{-Wno-globals} option also is specified.
  
  After using @samp{-fno-globals} to work around these problems,
--- 15214,15265 ----
  
  These messages all identify disagreements about the
! global procedure named @var{name} among different program units
! (usually including @var{name} itself).
  
! Whether a particular disagreement is reported
! as a warning or an error
! can depend on the relative order
! of the disagreeing portions of the source file.
! 
! Disagreements between a procedure invocation
! and the @emph{subsequent} procedure itself
! are, usually, diagnosed as errors
! when the procedure itself @emph{precedes} the invocation.
! Other disagreements are diagnosed via warnings.
! 
! @cindex forward references
! @cindex in-line code
! @cindex compilation, in-line
! This distinction, between warnings and errors,
! is due primarily to the present tendency of the @code{gcc} back end
! to inline only those procedure invocations that are
! @emph{preceded} by the corresponding procedure definitions.
! If the @code{gcc} back end is changed
! to inline ``forward references'',
! in which invocations precede definitions,
! the @code{g77} front end will be changed
! to treat both orderings as errors, accordingly.
! 
! The sorts of disagreements that are diagnosed by @code{g77} include
! whether a procedure is a subroutine or function;
! if it is a function, the type of the return value of the procedure;
! the number of arguments the procedure accepts;
! and the type of each argument.
! 
! Disagreements regarding global names among program units
! in a Fortran program @emph{should} be fixed in the code itself.
! However, if that is not immediately practical,
! and the code has been working for some time,
! it is possible it will work
! when compiled with the @samp{-fno-globals} option.
! 
! The @samp{-fno-globals} option
! causes these diagnostics to all be warnings
! and disables all inlining of references to global procedures
! (to avoid subsequent compiler crashes and bad-code generation).
! Use of the @samp{-Wno-globals} option as well as @samp{-fno-globals}
! suppresses all of these diagnostics.
! (@samp{-Wno-globals} by itself disables only the warnings,
! not the errors.)
  
  After using @samp{-fno-globals} to work around these problems,