Hi all,
here is a small patch that enables -Wconversion-extra with -Wextra and
updates the documentation.
Up to gfortran 5, the warning in the test case was enabled by
-Wconversion, and thus with -Wall. That was changed by Thomas in
r224190, which makes complete sense to me.
However, I think -Wconversion-extra should be implied by -Wextra (I'm
sure not everyone wants to see such messages, but I think they're
still useful).
The patch regtests cleanly on x86_64-linux-gnu. Ok for trunk?
As a sidenote, I made an observation that is not directly related to
the patch: The second warning in the test case, on "i4 = i8" shows
[-Wconversion] when compiled with -Wall, but [-Wconversion-extra] when
compiled with -Wextra. Does anyone understand how that inconsistency
comes about?
Cheers,
Janus
2017-09-16 Janus Weil <ja...@gcc.gnu.org>
PR fortran/82018
* lang.opt: Turn on -Wconversion-extra with -Wextra.
* invoke.texi: Update documentation of -Wconversion-extra and -Wextra
and mention both in the list of Error and Warning Options.
2017-09-16 Janus Weil <ja...@gcc.gnu.org>
PR fortran/82018
* gfortran.dg/wextra_2.f90: New test case.
Index: gcc/fortran/invoke.texi
===================================================================
--- gcc/fortran/invoke.texi (revision 252872)
+++ gcc/fortran/invoke.texi (working copy)
@@ -144,10 +144,10 @@ by type. Explanations are in the following sectio
@item Error and Warning Options
@xref{Error and Warning Options,,Options to request or suppress errors
and warnings}.
-@gccoptlist{-Waliasing -Wall -Wampersand -Wargument-mismatch -Warray-bounds
--Wc-binding-type -Wcharacter-truncation @gol
--Wconversion -Wfunction-elimination -Wimplicit-interface @gol
--Wimplicit-procedure -Wintrinsic-shadow -Wuse-without-only -Wintrinsics-std
@gol
+@gccoptlist{-Waliasing -Wall -Wampersand -Wargument-mismatch -Warray-bounds
@gol
+-Wc-binding-type -Wcharacter-truncation -Wconversion -Wconversion-extra @gol
+-Wextra -Wfunction-elimination -Wimplicit-interface -Wimplicit-procedure @gol
+-Wintrinsic-shadow -Wuse-without-only -Wintrinsics-std @gol
-Wline-truncation -Wno-align-commons -Wno-tabs -Wreal-q-constant @gol
-Wsurprising -Wunderflow -Wunused-parameter -Wrealloc-lhs -Wrealloc-lhs-all
@gol
-Wtarget-lifetime -fmax-errors=@var{n} -fsyntax-only -pedantic -pedantic-errors
@@ -884,7 +884,7 @@ the expression after conversion. Implied by @optio
@cindex warnings, conversion
@cindex conversion
Warn about implicit conversions between different types and kinds. This
-option does @emph{not} imply @option{-Wconversion}.
+option does @emph{not} imply @option{-Wconversion}. Implied by
@option{-Wextra}.
@item -Wextra
@opindex @code{Wextra}
@@ -891,8 +891,8 @@ Warn about implicit conversions between different
@cindex extra warnings
@cindex warnings, extra
Enables some warning options for usages of language features which
-may be problematic. This currently includes @option{-Wcompare-reals}
-and @option{-Wunused-parameter}.
+may be problematic. This currently includes @option{-Wcompare-reals},
+@option{-Wunused-parameter} and @option{-Wconversion-extra}.
@item -Wimplicit-interface
@opindex @code{Wimplicit-interface}
Index: gcc/fortran/lang.opt
===================================================================
--- gcc/fortran/lang.opt (revision 252872)
+++ gcc/fortran/lang.opt (working copy)
@@ -234,7 +234,7 @@ Fortran Var(warn_conversion) Warning LangEnabledBy
; Documented in C
Wconversion-extra
-Fortran Var(warn_conversion_extra) Warning
+Fortran Var(warn_conversion_extra) Warning LangEnabledBy(Fortran,Wextra)
Warn about most implicit conversions.
Wextra
! { dg-do compile }
! { dg-options "-Wall -Wextra" }
!
! PR 82018: -Wextra should imply -Wconversion-extra
!
! Contributed by Janus Weil <ja...@gcc.gnu.org>
implicit none
integer(kind=4) :: i4
integer(kind=8) :: i8
i8 = 2.0 ! { dg-warning "Conversion" }
i4 = i8 ! { dg-warning "Possible change of value in conversion" }
end
