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emacs/m4/manywarnings.m4
2023-01-01 05:31:12 -05:00

212 lines
6.5 KiB
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# manywarnings.m4 serial 23
dnl Copyright (C) 2008-2023 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_AS_VAR_APPEND([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.
#
# The effects of this macro depend on the current language (_AC_LANG).
AC_DEFUN([gl_MANYWARN_ALL_GCC],
[_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])
# Specialization for _AC_LANG = C.
AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
[
AC_LANG_PUSH([C])
dnl First, check for some issues that only occur when combining multiple
dnl gcc warning categories.
AC_REQUIRE([AC_PROG_CC])
if test -n "$GCC"; then
dnl Check if -Wextra -Werror -Wno-missing-field-initializers is supported
dnl with the current $CC $CFLAGS $CPPFLAGS.
AC_CACHE_CHECK([whether -Wno-missing-field-initializers is supported],
[gl_cv_cc_nomfi_supported],
[gl_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Wextra -Werror -Wno-missing-field-initializers"
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[]], [[]])],
[gl_cv_cc_nomfi_supported=yes],
[gl_cv_cc_nomfi_supported=no])
CFLAGS="$gl_save_CFLAGS"
])
if test "$gl_cv_cc_nomfi_supported" = yes; then
dnl Now check whether -Wno-missing-field-initializers is needed
dnl for the { 0, } construct.
AC_CACHE_CHECK([whether -Wno-missing-field-initializers is needed],
[gl_cv_cc_nomfi_needed],
[gl_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Wextra -Werror"
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[int f (void)
{
typedef struct { int a; int b; } s_t;
s_t s1 = { 0, };
return s1.b;
}
]],
[[]])],
[gl_cv_cc_nomfi_needed=no],
[gl_cv_cc_nomfi_needed=yes])
CFLAGS="$gl_save_CFLAGS"
])
fi
dnl Next, check if -Werror -Wuninitialized is useful with the
dnl user's choice of $CFLAGS; some versions of gcc warn that it
dnl has no effect if -O is not also used
AC_CACHE_CHECK([whether -Wuninitialized is supported],
[gl_cv_cc_uninitialized_supported],
[gl_save_CFLAGS="$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"
])
fi
# List all gcc warning categories.
# To compare this list to your installed GCC's, run this Bash command:
#
# comm -3 \
# <((sed -n 's/^ *\(-[^ 0-9][^ ]*\).*/\1/p' manywarnings.m4; \
# awk '/^[^#]/ {print $1}' ../build-aux/gcc-warning.spec) | sort) \
# <(LC_ALL=C gcc --help=warnings | sed -n 's/^ \(-[^ ]*\) .*/\1/p' | sort)
$1=
for gl_manywarn_item in -fanalyzer -fno-common \
-Wall \
-Warith-conversion \
-Wbad-function-cast \
-Wcast-align=strict \
-Wdate-time \
-Wdisabled-optimization \
-Wdouble-promotion \
-Wduplicated-branches \
-Wduplicated-cond \
-Wextra \
-Wformat-signedness \
-Winit-self \
-Winline \
-Winvalid-pch \
-Wlogical-op \
-Wmissing-declarations \
-Wmissing-include-dirs \
-Wmissing-prototypes \
-Wnested-externs \
-Wnull-dereference \
-Wold-style-definition \
-Wopenmp-simd \
-Woverlength-strings \
-Wpacked \
-Wpointer-arith \
-Wshadow \
-Wstack-protector \
-Wstrict-overflow \
-Wstrict-prototypes \
-Wsuggest-attribute=cold \
-Wsuggest-attribute=const \
-Wsuggest-attribute=format \
-Wsuggest-attribute=malloc \
-Wsuggest-attribute=noreturn \
-Wsuggest-attribute=pure \
-Wsuggest-final-methods \
-Wsuggest-final-types \
-Wsync-nand \
-Wsystem-headers \
-Wtrampolines \
-Wuninitialized \
-Wunknown-pragmas \
-Wunsafe-loop-optimizations \
-Wunused-macros \
-Wvariadic-macros \
-Wvector-operation-performance \
-Wvla \
-Wwrite-strings \
\
; do
gl_AS_VAR_APPEND([$1], [" $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_AS_VAR_APPEND([$1], [' -Warray-bounds=2'])
gl_AS_VAR_APPEND([$1], [' -Wattribute-alias=2'])
gl_AS_VAR_APPEND([$1], [' -Wbidi-chars=any,ucn'])
gl_AS_VAR_APPEND([$1], [' -Wformat-overflow=2'])
gl_AS_VAR_APPEND([$1], [' -Wformat=2'])
gl_AS_VAR_APPEND([$1], [' -Wformat-truncation=2'])
gl_AS_VAR_APPEND([$1], [' -Wimplicit-fallthrough=5'])
gl_AS_VAR_APPEND([$1], [' -Wshift-overflow=2'])
gl_AS_VAR_APPEND([$1], [' -Wuse-after-free=3'])
gl_AS_VAR_APPEND([$1], [' -Wunused-const-variable=2'])
gl_AS_VAR_APPEND([$1], [' -Wvla-larger-than=4031'])
# These are needed for older GCC versions.
if test -n "$GCC"; then
case `($CC --version) 2>/dev/null` in
'gcc (GCC) '[[0-3]].* | \
'gcc (GCC) '4.[[0-7]].*)
gl_AS_VAR_APPEND([$1], [' -fdiagnostics-show-option'])
gl_AS_VAR_APPEND([$1], [' -funit-at-a-time'])
;;
esac
fi
# Disable specific options as needed.
if test "$gl_cv_cc_nomfi_needed" = yes; then
gl_AS_VAR_APPEND([$1], [' -Wno-missing-field-initializers'])
fi
if test "$gl_cv_cc_uninitialized_supported" = no; then
gl_AS_VAR_APPEND([$1], [' -Wno-uninitialized'])
fi
# This warning have too many false alarms in GCC 11.2.1.
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101713
gl_AS_VAR_APPEND([$1], [' -Wno-analyzer-malloc-leak'])
AC_LANG_POP([C])
])
# Specialization for _AC_LANG = C++.
AC_DEFUN([gl_MANYWARN_ALL_GCC(C++)],
[
gl_MANYWARN_ALL_GCC_CXX_IMPL([$1])
])