[Libguestfs] [PATCH libguestfs 8/8] build: new configure-time option: --enable-gcc-warnings

[Richard W.M. Jones]

On Tue, Aug 18, 2009 at 03:49:45PM +0200, Jim Meyering wrote:
> From: Jim Meyering <meyering at redhat.com>
> 
> * configure.ac: Define/configure it.
> * src/Makefile.am: Use new variables.
> ---
>  configure.ac    |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  src/Makefile.am |    4 ++-
>  2 files changed, 64 insertions(+), 1 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index d74fffb..fc2f457 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -47,6 +47,67 @@ AC_PROG_CPP
>  gl_EARLY
>  gl_INIT
> 
> +AC_ARG_ENABLE([gcc-warnings],
> +  [AS_HELP_STRING([--enable-gcc-warnings],
> +                  [turn on lots of GCC warnings (for developers)])],
> +  [case $enableval in
> +     yes|no) ;;
> +     *)      AC_MSG_ERROR([bad value $enableval for gcc-warnings option]) ;;
> +   esac
> +   gl_gcc_warnings=$enableval],
> +  [gl_gcc_warnings=no]
> +)
> +
> +if test "$gl_gcc_warnings" = yes; then
> +  gl_WARN_ADD([-Werror], [WERROR_CFLAGS])
> +  AC_SUBST([WERROR_CFLAGS])
> +
> +  nw=
> +  # This, $nw, is the list of warnings we disable.
> +  nw="$nw -Wdeclaration-after-statement" # too useful to forbid
> +  nw="$nw -Waggregate-return"       # anachronistic
> +  nw="$nw -Wc++-compat"             # We don't care about C++ compilers
> +  nw="$nw -Wundef"                  # Warns on '#if GNULIB_FOO' etc in gnulib
> +  nw="$nw -Wtraditional"            # Warns on #elif which we use often
> +  nw="$nw -Wcast-qual"              # Too many warnings for now
> +  nw="$nw -Wconversion"             # Too many warnings for now
> +  nw="$nw -Wsystem-headers"         # Don't let system headers trigger warnings
> +  nw="$nw -Wsign-conversion"        # Too many warnings for now
> +  nw="$nw -Wtraditional-conversion" # Too many warnings for now
> +  nw="$nw -Wunreachable-code"       # Too many warnings for now
> +  nw="$nw -Wpadded"                 # Our structs are not padded
> +  nw="$nw -Wredundant-decls"        # openat.h declares e.g., mkdirat
> +  nw="$nw -Wlogical-op"             # any use of fwrite provokes this
> +  nw="$nw -Wvla"                    # two warnings in mount.c
> +  # things I might fix soon:
> +  nw="$nw -Wmissing-format-attribute" # daemon.h's asprintf_nowarn
> +  nw="$nw -Winline"                 # daemon.h's asprintf_nowarn
> +  nw="$nw -Wshadow"                 # numerous, plus we're not unanimous
> +  # ?? -Wstrict-overflow
> +
> +  gl_MANYWARN_ALL_GCC([ws])
> +  gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
> +  for w in $ws; do
> +    gl_WARN_ADD([$w])
> +  done
> +  gl_WARN_ADD([-Wno-unused-parameter]) # stubs.c
> +  gl_WARN_ADD([-Wno-jump-misses-init]) # stubs.c
> +  gl_WARN_ADD([-Wno-unused-variable]) # FIXME: only temporary, for guestfs_protocol.c, etc
> +
> +  # In spite of excluding -Wlogical-op above, it is enabled, as of
> +  # gcc 4.5.0 20090517, and it provokes warnings in cat.c, dd.c, truncate.c
> +  gl_WARN_ADD([-Wno-logical-op])
> +
> +  gl_WARN_ADD([-fdiagnostics-show-option])
> +
> +  AC_SUBST([WARN_CFLAGS])
> +
> +  AC_DEFINE([lint], [1], [Define to 1 if the compiler is checking for lint.])
> +  AC_DEFINE([_FORTIFY_SOURCE], [2],
> +    [enable compile-time and run-time bounds-checking, and some warnings])
> +  AC_DEFINE([GNULIB_PORTCHECK], [1], [enable some gnulib portability checks])
> +fi
> +
>  AC_C_PROTOTYPES
>  test "x$U" != "x" && AC_MSG_ERROR([Compiler not ANSI compliant])
> 
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 8d03a77..e38c336 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -115,7 +115,9 @@ libguestfs_la_SOURCES = \
>  noinst_LTLIBRARIES = libprotocol.la
>  libguestfs_la_LIBADD = libprotocol.la
> 
> -libguestfs_la_CFLAGS = -Wall -DGUESTFS_DEFAULT_PATH='"$(libdir)/guestfs"'
> +libguestfs_la_CFLAGS = \
> +  -DGUESTFS_DEFAULT_PATH='"$(libdir)/guestfs"' \
> +  $(WARN_CFLAGS) $(WERROR_CFLAGS)
> 
>  libguestfs_la_CPPFLAGS = -I$(top_srcdir)/gnulib/lib
> 
> -- 
> 1.6.4.378.g88f2f
> 
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> Libguestfs at redhat.com
> https://www.redhat.com/mailman/listinfo/libguestfs

ACK.

Rich.

-- 
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