Howdy! I've suggested, a long time ago, that we could start making use of GNULIB's compiler warnings from 'manywarnings' module. This is basically what we have been doing in a few projects that I (used to and still) maintain (like spice-gtk and libosinfo, for instance).
For now I didn't try to fix any of the warnings that we cannot cope with, mainly because I'm not sure whether you guys will agree on using it or not. Here is an experimental patch that works properly on Fedora 24. I still have to make some tests on RHEL-6, RHEL-7 and a few other systems (Debian, at least) in order to make sure that we won't break the build because of the patch. If you are okay with the change, I'll start going through the warnings that we cannot cope with and slowly start fixing them. Although, I have the feeling that fixing some of them would cause a lot of undesired changes, which will just bring troubles for ourselves when backporting fixes downstream (and here I'm talking about -Wformat-signedess, -Wsign-compare, -Wunused-parameter, ... for instance). I'm looking forward to hear some feedback! Best Regards, -- Fabiano Fidêncio
From f28376e37ad91ba933d8bbd380b7680bf2bca853 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fabiano=20Fid=C3=AAncio?= <[email protected]> Date: Thu, 11 Aug 2016 07:58:44 +0200 Subject: [PATCH] BUILD: Make use of GNULIB's compiler warning code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As GNULIB has the 'manywarnings' module, which basically turns on every GCC warning, let's make use of it. We can easily blacklist the warnings we cannot cope with, but the main goal should be to have enabled every possible GCC warning. When new GCC warnings are created the 'manywarnings' file can be refreshed from upstream GNULIB. Signed-off-by: Fabiano Fidêncio <[email protected]> --- Makefile.am | 7 +- configure.ac | 5 + src/manywarnings.m4 | 274 +++++++++++++++++++++++++++++++++++++++++++ src/sssd-compile-warnings.m4 | 73 ++++++++++++ src/warnings.m4 | 79 +++++++++++++ 5 files changed, 432 insertions(+), 6 deletions(-) create mode 100644 src/manywarnings.m4 create mode 100644 src/sssd-compile-warnings.m4 create mode 100644 src/warnings.m4 diff --git a/Makefile.am b/Makefile.am index 5d1d671..4c6a823 100644 --- a/Makefile.am +++ b/Makefile.am @@ -103,12 +103,7 @@ if WANT_AUX_INFO AM_CFLAGS += -aux-info [email protected] endif if HAVE_GCC - AM_CFLAGS += -Wall -Wshadow -Wstrict-prototypes -Wpointer-arith \ - -Wcast-qual -Wcast-align -Wwrite-strings -Wundef \ - -Werror-implicit-function-declaration -Winit-self \ - -Wmissing-include-dirs \ - -fno-strict-aliasing \ - -std=gnu99 + AM_CFLAGS += $(WARN_CFLAGS) endif pkgconfig_DATA = diff --git a/configure.ac b/configure.ac index 8760a85..d08bb87 100644 --- a/configure.ac +++ b/configure.ac @@ -11,6 +11,11 @@ m4_ifdef([AC_USE_SYSTEM_EXTENSIONS], [AC_USE_SYSTEM_EXTENSIONS], [AC_GNU_SOURCE]) +m4_include([src/warnings.m4]) +m4_include([src/manywarnings.m4]) +m4_include([src/sssd-compile-warnings.m4]) +SSSD_COMPILE_WARNINGS + CFLAGS="$CFLAGS -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE" diff --git a/src/manywarnings.m4 b/src/manywarnings.m4 new file mode 100644 index 0000000..90823b0 --- /dev/null +++ b/src/manywarnings.m4 @@ -0,0 +1,274 @@ +# manywarnings.m4 serial 8 +dnl Copyright (C) 2008-2016 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 for some issues that only occur when combining multiple + dnl gcc warning categories. + AC_REQUIRE([AC_PROG_CC]) + if test -n "$GCC"; then + + dnl Check if -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 + + dnl Next, check if -Werror -Wuninitialized is useful with the + dnl user's choice of $CFLAGS; some versions of gcc warn that it + dnl has no effect if -O is not also used + AC_MSG_CHECKING([whether -Wuninitialized is supported]) + AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [ + gl_save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS -Werror -Wuninitialized" + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM([[]], [[]])], + [gl_cv_cc_uninitialized_supported=yes], + [gl_cv_cc_uninitialized_supported=no]) + CFLAGS="$gl_save_CFLAGS"]) + AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported]) + + fi + + # List all gcc warning categories. + # To compare this list to your installed GCC's, run this Bash command: + # + # comm -3 \ + # <(sed -n 's/^ *\(-[^ ]*\) .*/\1/p' manywarnings.m4 | sort) \ + # <(gcc --help=warnings | sed -n 's/^ \(-[^ ]*\) .*/\1/p' | sort | + # grep -v -x -f <( + # awk '/^[^#]/ {print $1}' ../build-aux/gcc-warning.spec)) + + gl_manywarn_set= + for gl_manywarn_item in \ + -W \ + -Wabi \ + -Waddress \ + -Waggressive-loop-optimizations \ + -Wall \ + -Wattributes \ + -Wbad-function-cast \ + -Wbool-compare \ + -Wbuiltin-macro-redefined \ + -Wcast-align \ + -Wchar-subscripts \ + -Wchkp \ + -Wclobbered \ + -Wcomment \ + -Wcomments \ + -Wcoverage-mismatch \ + -Wcpp \ + -Wdate-time \ + -Wdeprecated \ + -Wdeprecated-declarations \ + -Wdesignated-init \ + -Wdisabled-optimization \ + -Wdiscarded-array-qualifiers \ + -Wdiscarded-qualifiers \ + -Wdiv-by-zero \ + -Wdouble-promotion \ + -Wduplicated-cond \ + -Wempty-body \ + -Wendif-labels \ + -Wenum-compare \ + -Wextra \ + -Wformat-contains-nul \ + -Wformat-extra-args \ + -Wformat-nonliteral \ + -Wformat-security \ + -Wformat-signedness \ + -Wformat-y2k \ + -Wformat-zero-length \ + -Wframe-address \ + -Wfree-nonheap-object \ + -Whsa \ + -Wignored-attributes \ + -Wignored-qualifiers \ + -Wimplicit \ + -Wimplicit-function-declaration \ + -Wimplicit-int \ + -Wincompatible-pointer-types \ + -Winit-self \ + -Winline \ + -Wint-conversion \ + -Wint-to-pointer-cast \ + -Winvalid-memory-model \ + -Winvalid-pch \ + -Wjump-misses-init \ + -Wlogical-not-parentheses \ + -Wlogical-op \ + -Wmain \ + -Wmaybe-uninitialized \ + -Wmemset-transposed-args \ + -Wmisleading-indentation \ + -Wmissing-braces \ + -Wmissing-declarations \ + -Wmissing-field-initializers \ + -Wmissing-include-dirs \ + -Wmissing-parameter-type \ + -Wmissing-prototypes \ + -Wmultichar \ + -Wnarrowing \ + -Wnested-externs \ + -Wnonnull \ + -Wnonnull-compare \ + -Wnull-dereference \ + -Wodr \ + -Wold-style-declaration \ + -Wold-style-definition \ + -Wopenmp-simd \ + -Woverflow \ + -Woverlength-strings \ + -Woverride-init \ + -Wpacked \ + -Wpacked-bitfield-compat \ + -Wparentheses \ + -Wpointer-arith \ + -Wpointer-sign \ + -Wpointer-to-int-cast \ + -Wpragmas \ + -Wreturn-local-addr \ + -Wreturn-type \ + -Wscalar-storage-order \ + -Wsequence-point \ + -Wshadow \ + -Wshift-count-negative \ + -Wshift-count-overflow \ + -Wshift-negative-value \ + -Wsizeof-array-argument \ + -Wsizeof-pointer-memaccess \ + -Wstack-protector \ + -Wstrict-aliasing \ + -Wstrict-overflow \ + -Wstrict-prototypes \ + -Wsuggest-attribute=const \ + -Wsuggest-attribute=format \ + -Wsuggest-attribute=noreturn \ + -Wsuggest-attribute=pure \ + -Wsuggest-final-methods \ + -Wsuggest-final-types \ + -Wswitch \ + -Wswitch-bool \ + -Wswitch-default \ + -Wsync-nand \ + -Wsystem-headers \ + -Wtautological-compare \ + -Wtrampolines \ + -Wtrigraphs \ + -Wtype-limits \ + -Wuninitialized \ + -Wunknown-pragmas \ + -Wunsafe-loop-optimizations \ + -Wunused \ + -Wunused-but-set-parameter \ + -Wunused-but-set-variable \ + -Wunused-function \ + -Wunused-label \ + -Wunused-local-typedefs \ + -Wunused-macros \ + -Wunused-parameter \ + -Wunused-result \ + -Wunused-value \ + -Wunused-variable \ + -Wvarargs \ + -Wvariadic-macros \ + -Wvector-operation-performance \ + -Wvla \ + -Wvolatile-register-var \ + -Wwrite-strings \ + \ + ; do + gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item" + done + + # gcc --help=warnings outputs an unusual form for these options; list + # them here so that the above 'comm' command doesn't report a false match. + gl_manywarn_set="$gl_manywarn_set -Warray-bounds=2" + gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc" + gl_manywarn_set="$gl_manywarn_set -Wshift-overflow=2" + gl_manywarn_set="$gl_manywarn_set -Wunused-const-variable=2" + + # These are needed for older GCC versions. + if test -n "$GCC"; then + case `($CC --version) 2>/dev/null` in + 'gcc (GCC) '[[0-3]].* | \ + 'gcc (GCC) '4.[[0-7]].*) + gl_manywarn_set="$gl_manywarn_set -fdiagnostics-show-option" + gl_manywarn_set="$gl_manywarn_set -funit-at-a-time" + ;; + esac + fi + + # Disable specific options as needed. + if test "$gl_cv_cc_nomfi_needed" = yes; then + gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers" + fi + + if test "$gl_cv_cc_uninitialized_supported" = no; then + gl_manywarn_set="$gl_manywarn_set -Wno-uninitialized" + fi + + $1=$gl_manywarn_set +]) diff --git a/src/sssd-compile-warnings.m4 b/src/sssd-compile-warnings.m4 new file mode 100644 index 0000000..01402cf --- /dev/null +++ b/src/sssd-compile-warnings.m4 @@ -0,0 +1,73 @@ +dnl +dnl Enable all known GCC compiler warnings, except for those +dnl we can't yet cope with +dnl +AC_DEFUN([SSSD_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]) + + # Get all possible GCC warnings + gl_MANYWARN_ALL_GCC([wantwarn]) + + # Check for $CC support of each warning + for w in $wantwarn; do + gl_WARN_ADD([$w]) + done + + # Use improved glibc headers + AH_VERBATIM([FORTIFY_SOURCE], + [/* Enable compile-time and run-time bounds-checking, and some warnings, + without upsetting newer glibc. */ + #if !defined _FORTIFY_SOURCE && defined __OPTIMIZE__ && __OPTIMIZE__ + # define _FORTIFY_SOURCE 2 + #endif + ]) + + # Extra special flags + gl_WARN_ADD([-fno-strict-aliasing]) + gl_WARN_ADD([-std=gnu99]) + gl_WARN_ADD([-Werror-implicit-declaration]) + + # These are the warnings that, currently, we cannot cope with + gl_WARN_ADD([-Wno-array-bounds]) + gl_WARN_ADD([-Wno-bad-function-cast]) + gl_WARN_ADD([-Wno-format-nonliteral]) + gl_WARN_ADD([-Wno-format-signedness]) + gl_WARN_ADD([-Wno-format-y2k]) + gl_WARN_ADD([-Wno-jump-misses-init]) + gl_WARN_ADD([-Wno-logical-op]) + gl_WARN_ADD([-Wno-missing-prototypes]) + gl_WARN_ADD([-Wno-missing-declarations]) + gl_WARN_ADD([-Wno-null-dereference]) + gl_WARN_ADD([-Wno-packed]) + gl_WARN_ADD([-Wno-sign-compare]) + gl_WARN_ADD([-Wno-stack-protector]) + gl_WARN_ADD([-Wno-strict-aliasing]) + gl_WARN_ADD([-Wno-strict-overflow]) + gl_WARN_ADD([-Wno-suggest-attribute=pure]) + gl_WARN_ADD([-Wno-suggest-attribute=const]) + gl_WARN_ADD([-Wno-suggest-attribute=format]) + gl_WARN_ADD([-Wno-suggest-attribute=noreturn]) + gl_WARN_ADD([-Wno-switch-default]) + gl_WARN_ADD([-Wno-unused-parameter]) + gl_WARN_ADD([-Wno-unused-macros]) + gl_WARN_ADD([-Wno-vla]) + + if test "$set_werror" = "yes" + then + gl_WARN_ADD([-Werror]) + fi + + AC_SUBST([WARN_CFLAGS]) +]) diff --git a/src/warnings.m4 b/src/warnings.m4 new file mode 100644 index 0000000..924e21d --- /dev/null +++ b/src/warnings.m4 @@ -0,0 +1,79 @@ +# warnings.m4 serial 11 +dnl Copyright (C) 2008-2016 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_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED], +# [PROGRAM = AC_LANG_PROGRAM()]) +# ----------------------------------------------------------------- +# Check if the compiler supports OPTION when compiling PROGRAM. +# +# FIXME: gl_Warn must be used unquoted until we can assume Autoconf +# 2.64 or newer. +AC_DEFUN([gl_COMPILER_OPTION_IF], +[AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl +AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl +AS_LITERAL_IF([$1], + [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))], + [gl_positive="$1" +case $gl_positive in + -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;; +esac +m4_pushdef([gl_Positive], [$gl_positive])])dnl +AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([gl_Warn]), [ + gl_save_compiler_FLAGS="$gl_Flags" + gl_AS_VAR_APPEND(m4_defn([gl_Flags]), + [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["]) + AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([])])], + [AS_VAR_SET(gl_Warn, [yes])], + [AS_VAR_SET(gl_Warn, [no])]) + gl_Flags="$gl_save_compiler_FLAGS" +]) +AS_VAR_IF(gl_Warn, [yes], [$2], [$3]) +m4_popdef([gl_Positive])dnl +AS_VAR_POPDEF([gl_Flags])dnl +AS_VAR_POPDEF([gl_Warn])dnl +]) + +# gl_UNKNOWN_WARNINGS_ARE_ERRORS +# ------------------------------ +# Clang doesn't complain about unknown warning options unless one also +# specifies -Wunknown-warning-option -Werror. Detect this. +AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS], +[gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option], + [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'], + [gl_unknown_warnings_are_errors=])]) + +# gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS], +# [PROGRAM = AC_LANG_PROGRAM()]) +# --------------------------------------------- +# Adds parameter to WARN_CFLAGS if the compiler supports it when +# compiling PROGRAM. For example, gl_WARN_ADD([-Wparentheses]). +# +# If VARIABLE is a variable name, AC_SUBST it. +AC_DEFUN([gl_WARN_ADD], +[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS]) +gl_COMPILER_OPTION_IF([$1], + [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])], + [], + [$3]) +m4_ifval([$2], + [AS_LITERAL_IF([$2], [AC_SUBST([$2])])], + [AC_SUBST([WARN_CFLAGS])])dnl +]) + +# Local Variables: +# mode: autoconf +# End: -- 2.7.4
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