Re: pkg/53046: pkg x11/libdrm doesn't compile on GNU/Linux

[David Shao <davshao%gmail.com@localhost>]

The following reply was made to PR pkg/53046; it has been noted by GNATS.

From: David Shao <davshao%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: pkg/53046: pkg x11/libdrm doesn't compile on GNU/Linux
Date: Wed, 21 Feb 2018 18:17:35 -0800

 One question is whether many platforms even need libatomic_ops
 as a dependency for libdrm, because it is possible that on i386 or x86_64,
 the only architectures for Intel, that the intel driver no longer needs
 libatomic_ops.
 
 The -Werror=undef CFLAG seems to come from configure.ac:
 
 MAYBE_WARN="-Wall -Wextra -Werror=undef \
 -Wsign-compare -Werror-implicit-function-declaration \
 -Wpointer-arith -Wwrite-strings -Wstrict-prototypes \
 -Wmissing-prototypes -Wmissing-declarations -Wnested-externs \
 -Wpacked -Wswitch-enum -Wmissing-format-attribute \
 -Wstrict-aliasing=2 -Winit-self \
 -Wdeclaration-after-statement -Wold-style-definition \
 -Wno-unused-parameter \
 -Wno-attributes -Wno-long-long -Winline -Wshadow \
 -Wno-missing-field-initializers"
 
 ...
 
 AC_CACHE_CHECK([for supported warning flags], libdrm_cv_warn_cflags, [
     echo
     WARN_CFLAGS=""
 
     # Some warning options are not supported by all versions of
     # gcc, so test all desired options against the current
     # compiler.
     #
     # Note that there are some order dependencies
     # here. Specifically, an option that disables a warning will
     # have no net effect if a later option then enables that
     # warnings, (perhaps implicitly). So we put some grouped
     # options (-Wall and -Wextra) up front and the -Wno options
     # last.
 
     for W in $MAYBE_WARN; do
         LIBDRM_CC_TRY_FLAG([$W], [WARN_CFLAGS="$WARN_CFLAGS $W"])
     done
 
     libdrm_cv_warn_cflags=$WARN_CFLAGS
     libdrm_cv_warn_maybe=$MAYBE_WARN
 
     AC_MSG_CHECKING([which warning flags were supported])])
 WARN_CFLAGS="$libdrm_cv_warn_cflags"