[Spice-devel] [PATCH spice 11/12] Enable many more compiler warnings
Alon Levy
alevy at redhat.com
Tue Apr 3 01:21:47 PDT 2012
On Mon, Apr 02, 2012 at 12:23:46PM +0100, Daniel P. Berrange wrote:
> From: "Daniel P. Berrange" <berrange at redhat.com>
What's the source for manywarnings.m4 and warnings.m4 ? Could you add a
link somewhere in the commit message?
>
> * m4/manywarnings.m4m, m4/warnings.m4: Import GNULIB warnings
> modules
> * m4/spice-compile-warnings.m4: Define SPICE_COMPILE_WARNINGS
> * configure.ac: Replace compile warning check with a call to
> SPICE_COMPILE_WARNINGS
> * client/Makefile.am: Use WARN_CXXFLAGS instead of WARN_CFLAGS
>
> Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> ---
> client/Makefile.am | 2 +-
> configure.ac | 77 +-----------------
> m4/manywarnings.m4 | 184 ++++++++++++++++++++++++++++++++++++++++++
> m4/spice-compile-warnings.m4 | 162 +++++++++++++++++++++++++++++++++++++
> m4/warnings.m4 | 37 +++++++++
> 5 files changed, 385 insertions(+), 77 deletions(-)
> create mode 100644 m4/manywarnings.m4
> create mode 100644 m4/spice-compile-warnings.m4
> create mode 100644 m4/warnings.m4
>
> diff --git a/client/Makefile.am b/client/Makefile.am
> index 22d5adf..ba3ce76 100644
> --- a/client/Makefile.am
> +++ b/client/Makefile.am
> @@ -213,7 +213,7 @@ INCLUDES = \
> $(SSL_CFLAGS) \
> $(XRANDR_CFLAGS) \
> $(XFIXES_CFLAGS) \
> - $(WARN_CFLAGS) \
> + $(WARN_CXXFLAGS) \
> $(XINERAMA_CFLAGS) \
> $(CXIMAGE_CFLAGS) \
> $(NULL)
> diff --git a/configure.ac b/configure.ac
> index 1feb36d..f5b014f 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -394,82 +394,7 @@ fi
> dnl ===========================================================================
> dnl check compiler flags
>
> -AC_DEFUN([SPICE_CC_TRY_FLAG], [
> - AC_MSG_CHECKING([whether $CC supports $1])
> -
> - spice_save_CFLAGS="$CFLAGS"
> - CFLAGS="$CFLAGS $1"
> -
> - AC_COMPILE_IFELSE([AC_LANG_SOURCE([ ])], [spice_cc_flag=yes], [spice_cc_flag=no])
> - CFLAGS="$spice_save_CFLAGS"
> -
> - if test "x$spice_cc_flag" = "xyes"; then
> - ifelse([$2], , :, [$2])
> - else
> - ifelse([$3], , :, [$3])
> - fi
> - AC_MSG_RESULT([$spice_cc_flag])
> -])
> -
> -
> -dnl Use lots of warning flags with with gcc and compatible compilers
> -
> -dnl Note: if you change the following variable, the cache is automatically
> -dnl skipped and all flags rechecked. So there's no need to do anything
> -dnl else. If for any reason you need to force a recheck, just change
> -dnl MAYBE_WARN in an ignorable way (like adding whitespace)
> -
> -dnl MAYBE_WARN="-Wall -Wno-sign-compare -Werror -Wno-deprecated-declarations"
> -
> -if test "$red_target" = "windows"; then
> - MAYBE_WARN="-Wall -Wno-sign-compare -Wno-deprecated-declarations"
> -else
> - MAYBE_WARN="-Wall -Wno-sign-compare -Wno-deprecated-declarations"
> -fi
> -
> -AC_ARG_ENABLE(werror,
> -AC_HELP_STRING([--enable-werror], [Use -Werror (if supported)]),
> -set_werror="$enableval",[
> -if test -f $srcdir/GITVERSION; then
> - is_git_version=true
> - set_werror=yes
> -else
> - set_werror=no
> -fi
> -])
> -
> -# invalidate cached value if MAYBE_WARN has changed
> -if test "x$spice_cv_warn_maybe" != "x$MAYBE_WARN"; then
> - unset spice_cv_warn_cflags
> -fi
> -AC_CACHE_CHECK([for supported warning flags], spice_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 $MAYBE_WARN; do
> - SPICE_CC_TRY_FLAG([$W], [WARN_CFLAGS="$WARN_CFLAGS $W"])
> - done
> - if test "$set_werror" != "no"; then
> - SPICE_CC_TRY_FLAG(["-Werror"], [WARN_CFLAGS="$WARN_CFLAGS -Werror"])
> - fi
> -
> - spice_cv_warn_cflags=$WARN_CFLAGS
> - spice_cv_warn_maybe=$MAYBE_WARN
> -
> - AC_MSG_CHECKING([which warning flags were supported])])
> -WARN_CFLAGS="$spice_cv_warn_cflags"
> -SPICE_CFLAGS="$SPICE_CFLAGS $WARN_CFLAGS"
> +SPICE_COMPILE_WARNINGS
>
> # use ximage.h for win32 build if it is found (no package for mingw32 atm)
> if test $os_win32 == "yes" ; then
> diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
> new file mode 100644
> index 0000000..fd0e372
> --- /dev/null
> +++ b/m4/manywarnings.m4
> @@ -0,0 +1,184 @@
> +# manywarnings.m4 serial 3
> +dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
> +dnl This file is free software; the Free Software Foundation
> +dnl gives unlimited permission to copy and/or distribute it,
> +dnl with or without modifications, as long as this notice is preserved.
> +
> +dnl From Simon Josefsson
> +
> +# gl_MANYWARN_COMPLEMENT(OUTVAR, LISTVAR, REMOVEVAR)
> +# --------------------------------------------------
> +# Copy LISTVAR to OUTVAR except for the entries in REMOVEVAR.
> +# Elements separated by whitespace. In set logic terms, the function
> +# does OUTVAR = LISTVAR \ REMOVEVAR.
> +AC_DEFUN([gl_MANYWARN_COMPLEMENT],
> +[
> + gl_warn_set=
> + set x $2; shift
> + for gl_warn_item
> + do
> + case " $3 " in
> + *" $gl_warn_item "*)
> + ;;
> + *)
> + gl_warn_set="$gl_warn_set $gl_warn_item"
> + ;;
> + esac
> + done
> + $1=$gl_warn_set
> +])
> +
> +# gl_MANYWARN_ALL_GCC(VARIABLE)
> +# -----------------------------
> +# Add all documented GCC warning parameters to variable VARIABLE.
> +# Note that you need to test them using gl_WARN_ADD if you want to
> +# make sure your gcc understands it.
> +AC_DEFUN([gl_MANYWARN_ALL_GCC],
> +[
> + dnl First, check if -Wno-missing-field-initializers is needed.
> + dnl -Wmissing-field-initializers is implied by -W, but that issues
> + dnl warnings with GCC version before 4.7, for the common idiom
> + dnl of initializing types on the stack to zero, using { 0, }
> + AC_REQUIRE([AC_PROG_CC])
> + if test -n "$GCC"; then
> +
> + dnl First, check -W -Werror -Wno-missing-field-initializers is supported
> + dnl with the current $CC $CFLAGS $CPPFLAGS.
> + AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported])
> + AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [
> + gl_save_CFLAGS="$CFLAGS"
> + CFLAGS="$CFLAGS -W -Werror -Wno-missing-field-initializers"
> + AC_COMPILE_IFELSE(
> + [AC_LANG_PROGRAM([[]], [[]])],
> + [gl_cv_cc_nomfi_supported=yes],
> + [gl_cv_cc_nomfi_supported=no])
> + CFLAGS="$gl_save_CFLAGS"])
> + AC_MSG_RESULT([$gl_cv_cc_nomfi_supported])
> +
> + if test "$gl_cv_cc_nomfi_supported" = yes; then
> + dnl Now check whether -Wno-missing-field-initializers is needed
> + dnl for the { 0, } construct.
> + AC_MSG_CHECKING([whether -Wno-missing-field-initializers is needed])
> + AC_CACHE_VAL([gl_cv_cc_nomfi_needed], [
> + gl_save_CFLAGS="$CFLAGS"
> + CFLAGS="$CFLAGS -W -Werror"
> + AC_COMPILE_IFELSE(
> + [AC_LANG_PROGRAM(
> + [[void f (void)
> + {
> + typedef struct { int a; int b; } s_t;
> + s_t s1 = { 0, };
> + }
> + ]],
> + [[]])],
> + [gl_cv_cc_nomfi_needed=no],
> + [gl_cv_cc_nomfi_needed=yes])
> + CFLAGS="$gl_save_CFLAGS"
> + ])
> + AC_MSG_RESULT([$gl_cv_cc_nomfi_needed])
> + fi
> + fi
> +
> + gl_manywarn_set=
> + for gl_manywarn_item in \
> + -Wall \
> + -W \
> + -Wformat-y2k \
> + -Wformat-nonliteral \
> + -Wformat-security \
> + -Winit-self \
> + -Wmissing-include-dirs \
> + -Wswitch-default \
> + -Wswitch-enum \
> + -Wunused \
> + -Wunknown-pragmas \
> + -Wstrict-aliasing \
> + -Wstrict-overflow \
> + -Wsystem-headers \
> + -Wfloat-equal \
> + -Wtraditional \
> + -Wtraditional-conversion \
> + -Wdeclaration-after-statement \
> + -Wundef \
> + -Wshadow \
> + -Wunsafe-loop-optimizations \
> + -Wpointer-arith \
> + -Wbad-function-cast \
> + -Wc++-compat \
> + -Wcast-qual \
> + -Wcast-align \
> + -Wwrite-strings \
> + -Wconversion \
> + -Wsign-conversion \
> + -Wlogical-op \
> + -Waggregate-return \
> + -Wstrict-prototypes \
> + -Wold-style-definition \
> + -Wmissing-prototypes \
> + -Wmissing-declarations \
> + -Wmissing-noreturn \
> + -Wmissing-format-attribute \
> + -Wpacked \
> + -Wpadded \
> + -Wredundant-decls \
> + -Wnested-externs \
> + -Wunreachable-code \
> + -Winline \
> + -Winvalid-pch \
> + -Wlong-long \
> + -Wvla \
> + -Wvolatile-register-var \
> + -Wdisabled-optimization \
> + -Wstack-protector \
> + -Woverlength-strings \
> + -Wbuiltin-macro-redefined \
> + -Wmudflap \
> + -Wpacked-bitfield-compat \
> + -Wsync-nand \
> + ; do
> + gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"
> + done
> + # The following are not documented in the manual but are included in
> + # output from gcc --help=warnings.
> + for gl_manywarn_item in \
> + -Wattributes \
> + -Wcoverage-mismatch \
> + -Wmultichar \
> + -Wunused-macros \
> + ; do
> + gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"
> + done
> + # More warnings from gcc 4.6.2 --help=warnings.
> + for gl_manywarn_item in \
> + -Wabi \
> + -Wcpp \
> + -Wdeprecated \
> + -Wdeprecated-declarations \
> + -Wdiv-by-zero \
> + -Wdouble-promotion \
> + -Wendif-labels \
> + -Wextra \
> + -Wformat-contains-nul \
> + -Wformat-extra-args \
> + -Wformat-zero-length \
> + -Wformat=2 \
> + -Wmultichar \
> + -Wnormalized=nfc \
> + -Woverflow \
> + -Wpointer-to-int-cast \
> + -Wpragmas \
> + -Wsuggest-attribute=const \
> + -Wsuggest-attribute=noreturn \
> + -Wsuggest-attribute=pure \
> + -Wtrampolines \
> + ; do
> + gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"
> + done
> +
> + # Disable the missing-field-initializers warning if needed
> + if test "$gl_cv_cc_nomfi_needed" = yes; then
> + gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers"
> + fi
> +
> + $1=$gl_manywarn_set
> +])
> diff --git a/m4/spice-compile-warnings.m4 b/m4/spice-compile-warnings.m4
> new file mode 100644
> index 0000000..8de2ffd
> --- /dev/null
> +++ b/m4/spice-compile-warnings.m4
> @@ -0,0 +1,162 @@
> +dnl
> +dnl Enable all known GCC compiler warnings, except for those
> +dnl we can't yet cope with
> +dnl
> +AC_DEFUN([SPICE_COMPILE_WARNINGS],[
> + dnl ******************************
> + dnl More compiler warnings
> + dnl ******************************
> +
> + AC_ARG_ENABLE([werror],
> + AS_HELP_STRING([--enable-werror], [Use -Werror (if supported)]),
> + [set_werror="$enableval"],
> + [if test -d $srcdir/.git; then
> + is_git_version=true
> + set_werror=yes
> + else
> + set_werror=no
> + fi])
> +
> + # List of warnings that are not relevant / wanted
> +
> + # Don't care about C++ compiler compat
> + dontwarn="$dontwarn -Wc++-compat"
> + dontwarn="$dontwarn -Wabi"
> + dontwarn="$dontwarn -Wdeprecated"
> + # Don't care about ancient C standard compat
> + dontwarn="$dontwarn -Wtraditional"
> + # Don't care about ancient C standard compat
> + dontwarn="$dontwarn -Wtraditional-conversion"
> + # Ignore warnings in /usr/include
> + dontwarn="$dontwarn -Wsystem-headers"
> + # Happy for compiler to add struct padding
> + dontwarn="$dontwarn -Wpadded"
> + # GCC very confused with -O2
> + dontwarn="$dontwarn -Wunreachable-code"
> +
> +
> + dontwarn="$dontwarn -Wconversion"
> + dontwarn="$dontwarn -Wsign-conversion"
> + dontwarn="$dontwarn -Wvla"
> + dontwarn="$dontwarn -Wundef"
> + dontwarn="$dontwarn -Wcast-qual"
> + dontwarn="$dontwarn -Wlong-long"
> + dontwarn="$dontwarn -Wswitch-default"
> + dontwarn="$dontwarn -Wswitch-enum"
> + dontwarn="$dontwarn -Wstrict-overflow"
> + dontwarn="$dontwarn -Wunsafe-loop-optimizations"
> + dontwarn="$dontwarn -Wformat-nonliteral"
> + dontwarn="$dontwarn -Wfloat-equal"
> + dontwarn="$dontwarn -Wdeclaration-after-statement"
> + dontwarn="$dontwarn -Wcast-qual"
> + dontwarn="$dontwarn -Wconversion"
> + dontwarn="$dontwarn -Wsign-conversion"
> + dontwarn="$dontwarn -Wpacked"
> + dontwarn="$dontwarn -Wunused-macros"
> + dontwarn="$dontwarn -Woverlength-strings"
> + dontwarn="$dontwarn -Wstack-protector"
> + dontwarn="$dontwarn -Winline"
> + dontwarn="$dontwarn -Wbad-function-cast"
> + dontwarn="$dontwarn -Wshadow"
> +
> + # We want to enable thse, but need to sort out the
> + # decl mess with gtk/generated_*.c
> + dontwarn="$dontwarn -Wmissing-prototypes"
> + dontwarn="$dontwarn -Wmissing-declarations"
> +
> + # Stuff that C++ won't allow. Turn them back on later
> + dontwarn="$dontwarn -Waggregate-return"
> + dontwarn="$dontwarn -Wstrict-prototypes"
> + dontwarn="$dontwarn -Wold-style-definition"
> + dontwarn="$dontwarn -Wnested-externs"
> + dontwarn="$dontwarn -Wformat-zero-length"
> + dontwarn="$dontwarn -Wpointer-to-int-cast"
> + dontwarn="$dontwarn -Wjump-misses-init"
> +
> + # Issues in x11/platform_utils.cpp prevent us turning this on
> + dontwarn="$dontwarn -Wmissing-format-attribute"
> +
> + # Get all possible GCC warnings
> + gl_MANYWARN_ALL_GCC([maybewarn])
> +
> + # Remove the ones we don't want, blacklisted earlier
> + gl_MANYWARN_COMPLEMENT([wantwarn], [$maybewarn], [$dontwarn])
> +
> + # Check for $CC support of each warning
> + for w in $wantwarn; do
> + gl_WARN_ADD([$w])
> + done
> +
> + # GNULIB uses '-W' (aka -Wextra) which includes a bunch of stuff.
> + # Unfortunately, this means you can't simply use '-Wsign-compare'
> + # with gl_MANYWARN_COMPLEMENT
> + # So we have -W enabled, and then have to explicitly turn off...
> + gl_WARN_ADD([-Wno-sign-compare])
> + gl_WARN_ADD([-Wno-unused-parameter])
> + # We can't enable this due to horrible spice_usb_device_get_description
> + # signature
> + gl_WARN_ADD([-Wno-format-nonliteral])
> + # CEGui headers cause violation of this
> + gl_WARN_ADD([-Wno-ignored-qualifiers])
> +
> +
> +
> +
> + # GNULIB turns on -Wformat=2 which implies -Wformat-nonliteral,
> + # so we need to manually re-exclude it.
> + gl_WARN_ADD([-Wno-format-nonliteral])
> +
> + # This should be < 1024 really. pixman_utils is the blackspot
> + # preventing lower usage
> + gl_WARN_ADD([-Wframe-larger-than=20460])
> +
> + # Use improved glibc headers
> + AC_DEFINE([_FORTIFY_SOURCE], [2],
> + [enable compile-time and run-time bounds-checking, and some warnings])
> +
> + # Extra special flags
> + dnl -fstack-protector stuff passes gl_WARN_ADD with gcc
> + dnl on Mingw32, but fails when actually used
> + case $host in
> + *-*-linux*)
> + dnl Fedora only uses -fstack-protector, but doesn't seem to
> + dnl be great overhead in adding -fstack-protector-all instead
> + dnl gl_WARN_ADD([-fstack-protector])
> + gl_WARN_ADD([-fstack-protector-all])
> + gl_WARN_ADD([--param=ssp-buffer-size=4])
> + ;;
> + esac
> + gl_WARN_ADD([-fexceptions])
> + gl_WARN_ADD([-fasynchronous-unwind-tables])
> + gl_WARN_ADD([-fdiagnostics-show-option])
> + gl_WARN_ADD([-funit-at-a-time])
> +
> + # Need -fipa-pure-const in order to make -Wsuggest-attribute=pure
> + # fire even without -O.
> + gl_WARN_ADD([-fipa-pure-const])
> +
> + # We should eventually enable this, but right now there are at
> + # least 75 functions triggering warnings.
> + gl_WARN_ADD([-Wno-suggest-attribute=pure])
> + gl_WARN_ADD([-Wno-suggest-attribute=const])
> +
> + if test "$set_werror" = "yes"
> + then
> + gl_WARN_ADD([-Werror])
> + fi
> + WARN_CXXFLAGS=$WARN_CFLAGS
> + AC_SUBST([WARN_CXXFLAGS])
> +
> + # These are C-only warnings
> + gl_WARN_ADD([-Waggregate-return])
> + gl_WARN_ADD([-Wstrict-prototypes])
> + gl_WARN_ADD([-Wold-style-definition])
> + gl_WARN_ADD([-Wnested-externs])
> + gl_WARN_ADD([-Wformat-zero-length])
> + gl_WARN_ADD([-Wpointer-to-int-cast])
> + gl_WARN_ADD([-Wjump-misses-init])
> +
> + WARN_LDFLAGS=$WARN_CFLAGS
> + AC_SUBST([WARN_CFLAGS])
> + AC_SUBST([WARN_LDFLAGS])
> +])
> diff --git a/m4/warnings.m4 b/m4/warnings.m4
> new file mode 100644
> index 0000000..69d05a6
> --- /dev/null
> +++ b/m4/warnings.m4
> @@ -0,0 +1,37 @@
> +# warnings.m4 serial 5
> +dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
> +dnl This file is free software; the Free Software Foundation
> +dnl gives unlimited permission to copy and/or distribute it,
> +dnl with or without modifications, as long as this notice is preserved.
> +
> +dnl From Simon Josefsson
> +
> +# gl_AS_VAR_APPEND(VAR, VALUE)
> +# ----------------------------
> +# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
> +m4_ifdef([AS_VAR_APPEND],
> +[m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])],
> +[m4_define([gl_AS_VAR_APPEND],
> +[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
> +
> +# gl_WARN_ADD(PARAMETER, [VARIABLE = WARN_CFLAGS])
> +# ------------------------------------------------
> +# Adds parameter to WARN_CFLAGS if the compiler supports it. For example,
> +# gl_WARN_ADD([-Wparentheses]).
> +AC_DEFUN([gl_WARN_ADD],
> +dnl FIXME: gl_Warn must be used unquoted until we can assume
> +dnl autoconf 2.64 or newer.
> +[AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_$1])dnl
> +AC_CACHE_CHECK([whether compiler handles $1], m4_defn([gl_Warn]), [
> + gl_save_CPPFLAGS="$CPPFLAGS"
> + CPPFLAGS="${CPPFLAGS} $1"
> + AC_PREPROC_IFELSE([AC_LANG_PROGRAM([])],
> + [AS_VAR_SET(gl_Warn, [yes])],
> + [AS_VAR_SET(gl_Warn, [no])])
> + CPPFLAGS="$gl_save_CPPFLAGS"
> +])
> +AS_VAR_IF(gl_Warn, [yes],
> + [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])])
> +AS_VAR_POPDEF([gl_Warn])dnl
> +m4_ifval([$2], [AS_LITERAL_IF([$2], [AC_SUBST([$2])], [])])dnl
> +])
> --
> 1.7.7.6
>
> _______________________________________________
> Spice-devel mailing list
> Spice-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/spice-devel
More information about the Spice-devel
mailing list