RW_PROG_CXX_WORKS
AM_CONDITIONAL([CXX_WORKS], [test "x$rw_cv_prog_cxx_works" = "xyes"])
+# Detect warning flags supported by the compiler, append them to WARN_CFLAGS.
+#
+# Pass -Werror as an extra flag during the test: this is needed to make the
+# -Wunknown-warning-option diagnostic fatal with clang.
+AX_APPEND_COMPILE_FLAGS([ dnl
+ -Wall dnl
+ ],
+ [WARN_CFLAGS],
+ [-Werror])
+
# Checks for programs.
AC_PROG_GREP
AC_PROG_MAKE_SET
AM_CONDITIONAL([BUILD_LIB_TESTPOINT], [test x$build_lib_testpoint = xyes])
AM_CONDITIONAL([BUILD_LIB_UST_CONSUMER], [test x$build_lib_ust_consumer = xyes])
-AM_CFLAGS="-Wall -fno-strict-aliasing $PTHREAD_CFLAGS"
+AM_CFLAGS="${WARN_CFLAGS} -fno-strict-aliasing $PTHREAD_CFLAGS"
AC_SUBST(AM_CFLAGS)
# The order in which the include folders are searched is important.
--- /dev/null
+# ============================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
+# ============================================================================
+#
+# SYNOPSIS
+#
+# AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+# For every FLAG1, FLAG2 it is checked whether the compiler works with the
+# flag. If it does, the flag is added FLAGS-VARIABLE
+#
+# If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+# CFLAGS) is used. During the check the flag is always added to the
+# current language's flags.
+#
+# If EXTRA-FLAGS is defined, it is added to the current language's default
+# flags (e.g. CFLAGS) when the check is done. The check is thus made with
+# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
+# force the compiler to issue an error when a bad flag is given.
+#
+# INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+# NOTE: This macro depends on the AX_APPEND_FLAG and
+# AX_CHECK_COMPILE_FLAG. Please keep this macro in sync with
+# AX_APPEND_LINK_FLAGS.
+#
+# LICENSE
+#
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 7
+
+AC_DEFUN([AX_APPEND_COMPILE_FLAGS],
+[AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
+AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+for flag in $1; do
+ AX_CHECK_COMPILE_FLAG([$flag], [AX_APPEND_FLAG([$flag], [$2])], [], [$3], [$4])
+done
+])dnl AX_APPEND_COMPILE_FLAGS
--- /dev/null
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
+#
+# DESCRIPTION
+#
+# FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
+# added in between.
+#
+# If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+# CFLAGS) is used. FLAGS-VARIABLE is not changed if it already contains
+# FLAG. If FLAGS-VARIABLE is unset in the shell, it is set to exactly
+# FLAG.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 8
+
+AC_DEFUN([AX_APPEND_FLAG],
+[dnl
+AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
+AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
+AS_VAR_SET_IF(FLAGS,[
+ AS_CASE([" AS_VAR_GET(FLAGS) "],
+ [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
+ [
+ AS_VAR_APPEND(FLAGS,[" $1"])
+ AC_RUN_LOG([: FLAGS="$FLAGS"])
+ ])
+ ],
+ [
+ AS_VAR_SET(FLAGS,[$1])
+ AC_RUN_LOG([: FLAGS="$FLAGS"])
+ ])
+AS_VAR_POPDEF([FLAGS])dnl
+])dnl AX_APPEND_FLAG
--- /dev/null
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+# Check whether the given FLAG works with the current language's compiler
+# or gives an error. (Warnings, however, are ignored)
+#
+# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+# success/failure.
+#
+# If EXTRA-FLAGS is defined, it is added to the current language's default
+# flags (e.g. CFLAGS) when the check is done. The check is thus made with
+# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
+# force the compiler to issue an error when a bad flag is given.
+#
+# INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 6
+
+AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+ ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+ _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+ AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+ [AS_VAR_SET(CACHEVAR,[yes])],
+ [AS_VAR_SET(CACHEVAR,[no])])
+ _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+ [m4_default([$2], :)],
+ [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_COMPILE_FLAGS
--- /dev/null
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_require_defined.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_REQUIRE_DEFINED(MACRO)
+#
+# DESCRIPTION
+#
+# AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
+# been defined and thus are available for use. This avoids random issues
+# where a macro isn't expanded. Instead the configure script emits a
+# non-fatal:
+#
+# ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
+#
+# It's like AC_REQUIRE except it doesn't expand the required macro.
+#
+# Here's an example:
+#
+# AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+#
+# LICENSE
+#
+# Copyright (c) 2014 Mike Frysinger <vapier@gentoo.org>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 2
+
+AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
+ m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])
+])dnl AX_REQUIRE_DEFINED