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|
AC_DEFUN([_NM_COMPILER_FLAG], [
CFLAGS_SAVED="$CFLAGS"
CFLAGS="$CFLAGS $GLIB_CFLAGS -Werror $1"
AC_MSG_CHECKING([whether $1 works as expected])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[]])], [
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[$2]])], [
AC_MSG_RESULT(yes)
CFLAGS="$CFLAGS_SAVED"
$3
],[
AC_MSG_RESULT(no)
CFLAGS="$CFLAGS_SAVED"
$4
])
],[
AC_MSG_RESULT(not supported)
CFLAGS="$CFLAGS_SAVED"
])
])
dnl Check whether a particular compiler flag is supported,
dnl add it to CFLAGS if it is
AC_DEFUN([NM_COMPILER_FLAG], [
_NM_COMPILER_FLAG([$1], [], [
CFLAGS="$CFLAGS $1"
$2
], [$3])
])
dnl Check whether a particular warning is not emitted with code provided,
dnl disable it in CFLAGS if the check fails.
AC_DEFUN([NM_COMPILER_WARNING], [
_NM_COMPILER_FLAG([-W$1], [$2], [CFLAGS="$CFLAGS -W$1"], [CFLAGS="$CFLAGS -Wno-$1"])
])
AC_DEFUN([NM_COMPILER_WARNINGS],
[AC_ARG_ENABLE(more-warnings,
AS_HELP_STRING([--enable-more-warnings], [Possible values: no/yes/error]),
set_more_warnings="$enableval",set_more_warnings=$1)
AC_MSG_CHECKING(for more warnings)
if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
AC_MSG_RESULT(yes)
dnl This is enabled in clang by default, makes little sense,
dnl and causes the build to abort with -Werror.
CFLAGS_SAVED="$CFLAGS"
CFLAGS="$CFLAGS -Qunused-arguments"
AC_COMPILE_IFELSE([AC_LANG_SOURCE([])], [], CFLAGS="$CFLAGS_SAVED")
unset CFLAGS_SAVED
dnl clang only warns about unknown warnings, unless
dnl called with "-Werror=unknown-warning-option"
dnl Test if the compiler supports that, and if it does
dnl attach it to the CFLAGS.
NM_COMPILER_WARNING([unknown-warning-option], [])
CFLAGS_MORE_WARNINGS="-Wall -std=gnu99"
if test "x$set_more_warnings" = xerror; then
CFLAGS_MORE_WARNINGS="$CFLAGS_MORE_WARNINGS -Werror"
fi
for option in \
-Wextra \
-Wdeclaration-after-statement \
-Wfloat-equal \
-Wformat-nonliteral \
-Wformat-security \
-Wimplicit-fallthrough \
-Wimplicit-function-declaration \
-Winit-self \
-Wlogical-op \
-Wmissing-declarations \
-Wmissing-include-dirs \
-Wmissing-prototypes \
-Wpointer-arith \
-Wshadow \
-Wshift-negative-value \
-Wstrict-prototypes \
-Wundef \
-Wvla \
-Wno-duplicate-decl-specifier \
-Wno-format-truncation \
-Wno-format-y2k \
-Wno-missing-field-initializers \
-Wno-pragmas \
-Wno-sign-compare \
-Wno-unused-parameter \
; do
dnl GCC 4.4 does not warn when checking for -Wno-* flags (https://gcc.gnu.org/wiki/FAQ#wnowarning)
_NM_COMPILER_FLAG([$(printf '%s' "$option" | sed 's/^-Wno-/-W/')], [],
[CFLAGS_MORE_WARNINGS="$CFLAGS_MORE_WARNINGS $option"], [])
done
unset option
dnl Disable warnings triggered by known compiler problems
dnl https://bugzilla.gnome.org/show_bug.cgi?id=745821
NM_COMPILER_WARNING([unknown-attributes], [#include <glib.h>])
dnl https://bugzilla.gnome.org/show_bug.cgi?id=744473
NM_COMPILER_WARNING([typedef-redefinition], [#include <gio/gio.h>])
dnl https://llvm.org/bugs/show_bug.cgi?id=21614
NM_COMPILER_WARNING([array-bounds],
[#include <string.h>]
[void f () { strcmp ("something", "0"); }]
)
dnl https://llvm.org/bugs/show_bug.cgi?id=22949
NM_COMPILER_WARNING([parentheses-equality],
[#include <sys/wait.h>]
[void f () { if (WIFCONTINUED(0)) return; }]
)
dnl systemd-dhcp's log_internal macro and our handle_warn are sometimes
dnl used in void context,u sometimes in int. Makes clang unhappy.
NM_COMPILER_WARNING([unused-value],
[#define yolo ({ (666 + 666); })]
[int f () { int i = yolo; yolo; return i; }]
)
dnl clang 3.9 would like to see "{ { 0 } }" here, but that does not
dnl look too wise.
NM_COMPILER_WARNING([missing-braces],
[union { int a[1]; int b[2]; } c = { 0 }]
)
CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS"
else
AC_MSG_RESULT(no)
fi
])
AC_DEFUN([NM_LTO],
[AC_ARG_ENABLE(lto, AS_HELP_STRING([--enable-lto], [Enable Link Time Optimization for smaller size (default: no)]))
if (test "${enable_lto}" = "yes"); then
CC_CHECK_FLAG_APPEND([lto_flags], [CFLAGS], [-flto])
if (test -n "${lto_flags}"); then
CFLAGS="-flto $CFLAGS"
else
AC_MSG_ERROR([Link Time Optimization -flto is not supported.])
fi
else
enable_lto='no'
fi
])
AC_DEFUN([NM_LD_GC],
[AC_ARG_ENABLE(ld-gc, AS_HELP_STRING([--enable-ld-gc], [Enable garbage collection of unused symbols on linking (default: auto)]))
if (test "${enable_ld_gc}" != "no"); then
CC_CHECK_FLAG_APPEND([ld_gc_flags], [CFLAGS], [-fdata-sections -ffunction-sections -Wl,--gc-sections])
if (test -n "${ld_gc_flags}"); then
enable_ld_gc="yes"
CFLAGS="$ld_gc_flags $CFLAGS"
else
if (test "${enable_ld_gc}" = "yes"); then
AC_MSG_ERROR([Unused symbol eviction requested but not supported.])
else
enable_ld_gc="no"
fi
fi
fi
])
|
