Re: GCC g++ 4.4.7 does not accept -std=c++03

[Jonathan Perkin <jperkin%joyent.com@localhost>]

* On 2019-06-28 at 09:17 BST, Ryo ONODERA wrote:

> Jonathan Perkin <jperkin%joyent.com@localhost> writes:
> 
> > * On 2019-06-26 at 16:56 BST, Ryo ONODERA wrote:
> >
> >> I will commit the following patch.
> >> 
> >> Index: mk/compiler/gcc.mk
> >> ===================================================================
> >> RCS file: /cvsroot/pkgsrc/mk/compiler/gcc.mk,v
> >> retrieving revision 1.198
> >> diff -u -r1.198 gcc.mk
> >> --- mk/compiler/gcc.mk	12 Nov 2018 14:22:58 -0000	1.198
> >> +++ mk/compiler/gcc.mk	26 Jun 2019 15:55:12 -0000
> >> @@ -185,6 +185,11 @@
> >>  .endif
> >>  _GCC_PKG=	gcc-${_GCC_VERSION:C/-.*$//}
> >>  
> >> +.if !empty(_GCC_VERSION:M[34].[1234].*)
> >> +BUILDLINK_TRANSFORM+=	opt:-std=c++03:-std=c++0x
> >> +BUILDLINK_TRANSFORM+=	opt:-std=gnu++03:-std=gnu++0x
> >> +.endif
> >> +
> >
> > If we're really going to do this (I don't see the point when so much
> > software now depends on newer compilers) then please do it properly
> > and abstract away the current _CXX_VERSION_REQD bits in mk/compiler.mk
> > into the separate compiler files and handle the logic in gcc.mk.
> 
> I have no idea about an history of _CXX_VERSION_REQD.
> However I feel that _CXX_VERSION_REQD should set GCC_REQD.
> Do you know why the current _CXX_VERSION_REQD does not handle
> GCC_REQD?

I'll leave it to the others to answer the latter part of this, as we
disagree on the way forward and I don't want to prejudice the
discussion.

As for _CXX_VERSION_REQD all I mean is that this should be done in the
proper way, abstracted into the compiler-specific files, so something
like (untested):

  mk/compiler/clang.mk:
  .for _std_ in gnu++14 c++14 gnu++11 c++11 gnu++0x c++0x gnu++03 c++03
  _CXX_STD_FLAG.${_std}?=	-std=${_std_}
  .endfor

  mk/compiler/gcc.mk:
  .for _std_ in gnu++14 c++14 gnu++11 c++11 gnu++0x c++0x gnu++03 c++03
  _CXX_STD_FLAG.${_std}?=	-std=${_std_}
  .endfor
  .if !empty(_GCC_VERSION:M[34].[1234].*)
  _CXX_STD_FLAG.c++03=		-std=c++0x
  _CXX_STD_FLAG.gnu++03=	-std=gnu++0x
  .endif

  mk/compiler.mk:
  CWRAPPERS_PREPEND.cxx+=	${_CXX_STD_FLAG.${_CXX_VERSION_REQD}}

You get the idea.  This way we're cleanly setting the flag once, not
setting it first to the wrong value in compiler.mk and then fixing it
up with transformations later.

-- 
Jonathan Perkin  -  Joyent, Inc.  -  www.joyent.com