# manywarnings.m4 serial 8
dnl Copyright (C) 2008-2017 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(
[[int f (void)
{
typedef struct { int a; int b; } s_t;
s_t s1 = { 0, };
return s1.b;
}
]],
[[]])],
[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 -f <(
# awk '/^[^#]/ {print $1}' ../build-aux/gcc-warning.spec))
gl_manywarn_set=
for gl_manywarn_item in -fno-common \
-W \
-Wabi \
-Waddress \
-Waggressive-loop-optimizations \
-Wall \
-Wattributes \
-Wbad-function-cast \
-Wbool-compare \
-Wbool-operation \
-Wbuiltin-declaration-mismatch \
-Wbuiltin-macro-redefined \
-Wcast-align \
-Wchar-subscripts \
-Wchkp \
-Wclobbered \
-Wcomment \
-Wcomments \
-Wcoverage-mismatch \
-Wcpp \
-Wdangling-else \
-Wdate-time \
-Wdeprecated \
-Wdeprecated-declarations \
-Wdesignated-init \
-Wdisabled-optimization \
-Wdiscarded-array-qualifiers \
-Wdiscarded-qualifiers \
-Wdiv-by-zero \
-Wdouble-promotion \
-Wduplicated-branches \
-Wduplicated-cond \
-Wduplicate-decl-specifier \
-Wempty-body \
-Wendif-labels \
-Wenum-compare \
-Wexpansion-to-defined \
-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-in-bool-context \
-Wint-to-pointer-cast \
-Winvalid-memory-model \
-Winvalid-pch \
-Wjump-misses-init \
-Wlogical-not-parentheses \
-Wlogical-op \
-Wmain \
-Wmaybe-uninitialized \
-Wmemset-elt-size \
-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-compare \
-Wpointer-sign \
-Wpointer-to-int-cast \
-Wpragmas \
-Wpsabi \
-Wrestrict \
-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 \
-Wswitch-unreachable \
-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 $gl_manywarn_item"
done
# gcc --help=warnings outputs an unusual form for these options; list
# them here so that the above 'comm' command doesn't report a false match.
# Would prefer "min (PTRDIFF_MAX, SIZE_MAX)", but it must be a literal:
ptrdiff_max_max=9223372036854775807
gl_manywarn_set="$gl_manywarn_set -Walloc-size-larger-than=$ptrdiff_max_max"
gl_manywarn_set="$gl_manywarn_set -Warray-bounds=2"
gl_manywarn_set="$gl_manywarn_set -Wformat-overflow=2"
gl_manywarn_set="$gl_manywarn_set -Wformat-truncation=2"
gl_manywarn_set="$gl_manywarn_set -Wimplicit-fallthrough=5"
gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc"
gl_manywarn_set="$gl_manywarn_set -Wshift-overflow=2"
gl_manywarn_set="$gl_manywarn_set -Wstringop-overflow=2"
gl_manywarn_set="$gl_manywarn_set -Wunused-const-variable=2"
gl_manywarn_set="$gl_manywarn_set -Wvla-larger-than=4031"
# 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
])