Remove compile warning
diff --git a/aclocal.m4 b/aclocal.m4
index 24f9616..3aec86f 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -20,6 +20,771 @@
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically 'autoreconf'.])])
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS])
+#
+# 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.
+#
+# 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>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception, the respective Autoconf Macro's copyright owner
+# gives unlimited permission to copy, distribute and modify the configure
+# scripts that are the output of Autoconf when processing the Macro. You
+# need not follow the terms of the GNU General Public License when using
+# or distributing such scripts, even though portions of the text of the
+# Macro appear in them. The GNU General Public License (GPL) does govern
+# all other use of the material that constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the Autoconf
+# Macro released by the Autoconf Archive. When you make and distribute a
+# modified version of the Autoconf Macro, you may extend this special
+# exception to the GPL to apply to your modified version as well.
+
+#serial 4
+
+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])
+done
+])dnl AX_APPEND_COMPILE_FLAGS
+
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_APPEND_LINK_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS])
+#
+# DESCRIPTION
+#
+# For every FLAG1, FLAG2 it is checked whether the linker works with the
+# flag. If it does, the flag is added FLAGS-VARIABLE
+#
+# If FLAGS-VARIABLE is not specified, the linker's flags (LDFLAGS) is
+# used. During the check the flag is always added to the linker's flags.
+#
+# If EXTRA-FLAGS is defined, it is added to the linker's default flags
+# when the check is done. The check is thus made with the flags: "LDFLAGS
+# EXTRA-FLAGS FLAG". This can for example be used to force the linker to
+# issue an error when a bad flag is given.
+#
+# NOTE: This macro depends on the AX_APPEND_FLAG and AX_CHECK_LINK_FLAG.
+# Please keep this macro in sync with AX_APPEND_COMPILE_FLAGS.
+#
+# LICENSE
+#
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception, the respective Autoconf Macro's copyright owner
+# gives unlimited permission to copy, distribute and modify the configure
+# scripts that are the output of Autoconf when processing the Macro. You
+# need not follow the terms of the GNU General Public License when using
+# or distributing such scripts, even though portions of the text of the
+# Macro appear in them. The GNU General Public License (GPL) does govern
+# all other use of the material that constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the Autoconf
+# Macro released by the Autoconf Archive. When you make and distribute a
+# modified version of the Autoconf Macro, you may extend this special
+# exception to the GPL to apply to your modified version as well.
+
+#serial 4
+
+AC_DEFUN([AX_APPEND_LINK_FLAGS],
+[AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+for flag in $1; do
+ AX_CHECK_LINK_FLAG([$flag], [AX_APPEND_FLAG([$flag], [m4_default([$2], [LDFLAGS])])], [], [$3])
+done
+])dnl AX_APPEND_LINK_FLAGS
+
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+# Check whether the given FLAG works with the linker 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 linker's default flags
+# when the check is done. The check is thus made with the flags: "LDFLAGS
+# EXTRA-FLAGS FLAG". This can for example be used to force the linker to
+# issue an error when a bad flag is given.
+#
+# INPUT gives an alternative input source to AC_LINK_IFELSE.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+# macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception, the respective Autoconf Macro's copyright owner
+# gives unlimited permission to copy, distribute and modify the configure
+# scripts that are the output of Autoconf when processing the Macro. You
+# need not follow the terms of the GNU General Public License when using
+# or distributing such scripts, even though portions of the text of the
+# Macro appear in them. The GNU General Public License (GPL) does govern
+# all other use of the material that constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the Autoconf
+# Macro released by the Autoconf Archive. When you make and distribute a
+# modified version of the Autoconf Macro, you may extend this special
+# exception to the GPL to apply to your modified version as well.
+
+#serial 4
+
+AC_DEFUN([AX_CHECK_LINK_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
+ ax_check_save_flags=$LDFLAGS
+ LDFLAGS="$LDFLAGS $4 $1"
+ AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+ [AS_VAR_SET(CACHEVAR,[yes])],
+ [AS_VAR_SET(CACHEVAR,[no])])
+ LDFLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+ [m4_default([$2], :)],
+ [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_LINK_FLAGS
+
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_compiler_flags.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_COMPILER_FLAGS([CFLAGS-VARIABLE], [LDFLAGS-VARIABLE], [IS-RELEASE], [EXTRA-BASE-CFLAGS], [EXTRA-YES-CFLAGS], [UNUSED], [UNUSED], [UNUSED], [EXTRA-BASE-LDFLAGS], [EXTRA-YES-LDFLAGS], [UNUSED], [UNUSED], [UNUSED])
+#
+# DESCRIPTION
+#
+# Check for the presence of an --enable-compile-warnings option to
+# configure, defaulting to "error" in normal operation, or "yes" if
+# IS-RELEASE is equal to "yes". Return the value in the variable
+# $ax_enable_compile_warnings.
+#
+# Depending on the value of --enable-compile-warnings, different compiler
+# warnings are checked to see if they work with the current compiler and,
+# if so, are appended to CFLAGS-VARIABLE and LDFLAGS-VARIABLE. This
+# allows a consistent set of baseline compiler warnings to be used across
+# a code base, irrespective of any warnings enabled locally by individual
+# developers. By standardising the warnings used by all developers of a
+# project, the project can commit to a zero-warnings policy, using -Werror
+# to prevent compilation if new warnings are introduced. This makes
+# catching bugs which are flagged by warnings a lot easier.
+#
+# By providing a consistent --enable-compile-warnings argument across all
+# projects using this macro, continuous integration systems can easily be
+# configured the same for all projects. Automated systems or build
+# systems aimed at beginners may want to pass the --disable-Werror
+# argument to unconditionally prevent warnings being fatal.
+#
+# --enable-compile-warnings can take the values:
+#
+# * no: Base compiler warnings only; not even -Wall.
+# * yes: The above, plus a broad range of useful warnings.
+# * error: The above, plus -Werror so that all warnings are fatal.
+# Use --disable-Werror to override this and disable fatal
+# warnings.
+#
+# The set of base and enabled flags can be augmented using the
+# EXTRA-*-CFLAGS and EXTRA-*-LDFLAGS variables, which are tested and
+# appended to the output variable if --enable-compile-warnings is not
+# "no". Flags should not be disabled using these arguments, as the entire
+# point of AX_COMPILER_FLAGS is to enforce a consistent set of useful
+# compiler warnings on code, using warnings which have been chosen for low
+# false positive rates. If a compiler emits false positives for a
+# warning, a #pragma should be used in the code to disable the warning
+# locally. See:
+#
+# https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Diagnostic-Pragmas.html#Diagnostic-Pragmas
+#
+# The EXTRA-* variables should only be used to supply extra warning flags,
+# and not general purpose compiler flags, as they are controlled by
+# configure options such as --disable-Werror.
+#
+# IS-RELEASE can be used to disable -Werror when making a release, which
+# is useful for those hairy moments when you just want to get the release
+# done as quickly as possible. Set it to "yes" to disable -Werror. By
+# default, it uses the value of $ax_is_release, so if you are using the
+# AX_IS_RELEASE macro, there is no need to pass this parameter. For
+# example:
+#
+# AX_IS_RELEASE([git-directory])
+# AX_COMPILER_FLAGS()
+#
+# CFLAGS-VARIABLE defaults to WARN_CFLAGS, and LDFLAGS-VARIABLE defaults
+# to WARN_LDFLAGS. Both variables are AC_SUBST-ed by this macro, but must
+# be manually added to the CFLAGS and LDFLAGS variables for each target in
+# the code base.
+#
+# If C++ language support is enabled with AC_PROG_CXX, which must occur
+# before this macro in configure.ac, warning flags for the C++ compiler
+# are AC_SUBST-ed as WARN_CXXFLAGS, and must be manually added to the
+# CXXFLAGS variables for each target in the code base. EXTRA-*-CFLAGS can
+# be used to augment the base and enabled flags.
+#
+# Warning flags for g-ir-scanner (from GObject Introspection) are
+# AC_SUBST-ed as WARN_SCANNERFLAGS. This variable must be manually added
+# to the SCANNERFLAGS variable for each GIR target in the code base. If
+# extra g-ir-scanner flags need to be enabled, the AX_COMPILER_FLAGS_GIR
+# macro must be invoked manually.
+#
+# AX_COMPILER_FLAGS may add support for other tools in future, in addition
+# to the compiler and linker. No extra EXTRA-* variables will be added
+# for those tools, and all extra support will still use the single
+# --enable-compile-warnings configure option. For finer grained control
+# over the flags for individual tools, use AX_COMPILER_FLAGS_CFLAGS,
+# AX_COMPILER_FLAGS_LDFLAGS and AX_COMPILER_FLAGS_* for new tools.
+#
+# The UNUSED variables date from a previous version of this macro, and are
+# automatically appended to the preceding non-UNUSED variable. They should
+# be left empty in new uses of the macro.
+#
+# LICENSE
+#
+# Copyright (c) 2014, 2015 Philip Withnall <philip@tecnocode.co.uk>
+# Copyright (c) 2015 David King <amigadave@amigadave.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 13
+
+# _AX_COMPILER_FLAGS_LANG([LANGNAME])
+m4_defun([_AX_COMPILER_FLAGS_LANG],
+[m4_ifdef([_AX_COMPILER_FLAGS_LANG_]$1[_enabled], [],
+ [m4_define([_AX_COMPILER_FLAGS_LANG_]$1[_enabled], [])dnl
+ AX_REQUIRE_DEFINED([AX_COMPILER_FLAGS_]$1[FLAGS])])dnl
+])
+
+AC_DEFUN([AX_COMPILER_FLAGS],[
+ # C support is enabled by default.
+ _AX_COMPILER_FLAGS_LANG([C])
+ # Only enable C++ support if AC_PROG_CXX is called. The redefinition of
+ # AC_PROG_CXX is so that a fatal error is emitted if this macro is called
+ # before AC_PROG_CXX, which would otherwise cause no C++ warnings to be
+ # checked.
+ AC_PROVIDE_IFELSE([AC_PROG_CXX],
+ [_AX_COMPILER_FLAGS_LANG([CXX])],
+ [m4_define([AC_PROG_CXX], defn([AC_PROG_CXX])[_AX_COMPILER_FLAGS_LANG([CXX])])])
+ AX_REQUIRE_DEFINED([AX_COMPILER_FLAGS_LDFLAGS])
+
+ # Default value for IS-RELEASE is $ax_is_release
+ ax_compiler_flags_is_release=m4_tolower(m4_normalize(ifelse([$3],,
+ [$ax_is_release],
+ [$3])))
+
+ AC_ARG_ENABLE([compile-warnings],
+ AS_HELP_STRING([--enable-compile-warnings=@<:@no/yes/error@:>@],
+ [Enable compiler warnings and errors]),,
+ [AS_IF([test "$ax_compiler_flags_is_release" = "yes"],
+ [enable_compile_warnings="yes"],
+ [enable_compile_warnings="error"])])
+ AC_ARG_ENABLE([Werror],
+ AS_HELP_STRING([--disable-Werror],
+ [Unconditionally make all compiler warnings non-fatal]),,
+ [enable_Werror=maybe])
+
+ # Return the user's chosen warning level
+ AS_IF([test "$enable_Werror" = "no" -a \
+ "$enable_compile_warnings" = "error"],[
+ enable_compile_warnings="yes"
+ ])
+
+ ax_enable_compile_warnings=$enable_compile_warnings
+
+ AX_COMPILER_FLAGS_CFLAGS([$1],[$ax_compiler_flags_is_release],
+ [$4],[$5 $6 $7 $8])
+ m4_ifdef([_AX_COMPILER_FLAGS_LANG_CXX_enabled],
+ [AX_COMPILER_FLAGS_CXXFLAGS([WARN_CXXFLAGS],
+ [$ax_compiler_flags_is_release],
+ [$4],[$5 $6 $7 $8])])
+ AX_COMPILER_FLAGS_LDFLAGS([$2],[$ax_compiler_flags_is_release],
+ [$9],[$10 $11 $12 $13])
+ AX_COMPILER_FLAGS_GIR([WARN_SCANNERFLAGS],[$ax_compiler_flags_is_release])
+])dnl AX_COMPILER_FLAGS
+
+# ============================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_cflags.html
+# ============================================================================
+#
+# SYNOPSIS
+#
+# AX_COMPILER_FLAGS_CFLAGS([VARIABLE], [IS-RELEASE], [EXTRA-BASE-FLAGS], [EXTRA-YES-FLAGS])
+#
+# DESCRIPTION
+#
+# Add warning flags for the C compiler to VARIABLE, which defaults to
+# WARN_CFLAGS. VARIABLE is AC_SUBST-ed by this macro, but must be
+# manually added to the CFLAGS variable for each target in the code base.
+#
+# This macro depends on the environment set up by AX_COMPILER_FLAGS.
+# Specifically, it uses the value of $ax_enable_compile_warnings to decide
+# which flags to enable.
+#
+# LICENSE
+#
+# Copyright (c) 2014, 2015 Philip Withnall <philip@tecnocode.co.uk>
+#
+# 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 11
+
+AC_DEFUN([AX_COMPILER_FLAGS_CFLAGS],[
+ AC_REQUIRE([AC_PROG_SED])
+ AX_REQUIRE_DEFINED([AX_APPEND_COMPILE_FLAGS])
+ AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+ AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
+
+ # Variable names
+ m4_define(ax_warn_cflags_variable,
+ [m4_normalize(ifelse([$1],,[WARN_CFLAGS],[$1]))])
+
+ AC_LANG_PUSH([C])
+
+ # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
+ # flags, otherwise they are always appended to the warn_cflags variable, and
+ # Clang warns on them for every compilation unit.
+ # If this is passed to GCC, it will explode, so the flag must be enabled
+ # conditionally.
+ AX_CHECK_COMPILE_FLAG([-Werror=unknown-warning-option],[
+ ax_compiler_flags_test="-Werror=unknown-warning-option"
+ ],[
+ ax_compiler_flags_test=""
+ ])
+
+ # Base flags
+ AX_APPEND_COMPILE_FLAGS([ dnl
+ -fno-strict-aliasing dnl
+ $3 dnl
+ ],ax_warn_cflags_variable,[$ax_compiler_flags_test])
+
+ AS_IF([test "$ax_enable_compile_warnings" != "no"],[
+ # "yes" flags
+ AX_APPEND_COMPILE_FLAGS([ dnl
+ -Wall dnl
+ -Wextra dnl
+ -Wundef dnl
+ -Wnested-externs dnl
+ -Wwrite-strings dnl
+ -Wpointer-arith dnl
+ -Wmissing-declarations dnl
+ -Wmissing-prototypes dnl
+ -Wstrict-prototypes dnl
+ -Wredundant-decls dnl
+ -Wno-unused-parameter dnl
+ -Wno-missing-field-initializers dnl
+ -Wdeclaration-after-statement dnl
+ -Wformat=2 dnl
+ -Wold-style-definition dnl
+ -Wcast-align dnl
+ -Wformat-nonliteral dnl
+ -Wformat-security dnl
+ -Wsign-compare dnl
+ -Wstrict-aliasing dnl
+ -Wshadow dnl
+ -Winline dnl
+ -Wpacked dnl
+ -Wmissing-format-attribute dnl
+ -Wmissing-noreturn dnl
+ -Winit-self dnl
+ -Wredundant-decls dnl
+ -Wmissing-include-dirs dnl
+ -Wunused-but-set-variable dnl
+ -Warray-bounds dnl
+ -Wimplicit-function-declaration dnl
+ -Wreturn-type dnl
+ -Wswitch-enum dnl
+ -Wswitch-default dnl
+ $4 dnl
+ $5 dnl
+ $6 dnl
+ $7 dnl
+ ],ax_warn_cflags_variable,[$ax_compiler_flags_test])
+ ])
+ AS_IF([test "$ax_enable_compile_warnings" = "error"],[
+ # "error" flags; -Werror has to be appended unconditionally because
+ # it's not possible to test for
+ #
+ # suggest-attribute=format is disabled because it gives too many false
+ # positives
+ AX_APPEND_FLAG([-Werror],ax_warn_cflags_variable)
+
+ AX_APPEND_COMPILE_FLAGS([ dnl
+ -Wno-suggest-attribute=format dnl
+ ],ax_warn_cflags_variable,[$ax_compiler_flags_test])
+ ])
+
+ # In the flags below, when disabling specific flags, always add *both*
+ # -Wno-foo and -Wno-error=foo. This fixes the situation where (for example)
+ # we enable -Werror, disable a flag, and a build bot passes CFLAGS=-Wall,
+ # which effectively turns that flag back on again as an error.
+ for flag in $ax_warn_cflags_variable; do
+ AS_CASE([$flag],
+ [-Wno-*=*],[],
+ [-Wno-*],[
+ AX_APPEND_COMPILE_FLAGS([-Wno-error=$(AS_ECHO([$flag]) | $SED 's/^-Wno-//')],
+ ax_warn_cflags_variable,
+ [$ax_compiler_flags_test])
+ ])
+ done
+
+ AC_LANG_POP([C])
+
+ # Substitute the variables
+ AC_SUBST(ax_warn_cflags_variable)
+])dnl AX_COMPILER_FLAGS
+
+# ==============================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_cxxflags.html
+# ==============================================================================
+#
+# SYNOPSIS
+#
+# AX_COMPILER_FLAGS_CXXFLAGS([VARIABLE], [IS-RELEASE], [EXTRA-BASE-FLAGS], [EXTRA-YES-FLAGS])
+#
+# DESCRIPTION
+#
+# Add warning flags for the C++ compiler to VARIABLE, which defaults to
+# WARN_CXXFLAGS. VARIABLE is AC_SUBST-ed by this macro, but must be
+# manually added to the CXXFLAGS variable for each target in the code
+# base.
+#
+# This macro depends on the environment set up by AX_COMPILER_FLAGS.
+# Specifically, it uses the value of $ax_enable_compile_warnings to decide
+# which flags to enable.
+#
+# LICENSE
+#
+# Copyright (c) 2015 David King <amigadave@amigadave.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_COMPILER_FLAGS_CXXFLAGS],[
+ AC_REQUIRE([AC_PROG_SED])
+ AX_REQUIRE_DEFINED([AX_APPEND_COMPILE_FLAGS])
+ AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+ AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
+
+ # Variable names
+ m4_define(ax_warn_cxxflags_variable,
+ [m4_normalize(ifelse([$1],,[WARN_CXXFLAGS],[$1]))])
+
+ AC_LANG_PUSH([C++])
+
+ # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
+ # flags, otherwise they are always appended to the warn_cxxflags variable,
+ # and Clang warns on them for every compilation unit.
+ # If this is passed to GCC, it will explode, so the flag must be enabled
+ # conditionally.
+ AX_CHECK_COMPILE_FLAG([-Werror=unknown-warning-option],[
+ ax_compiler_flags_test="-Werror=unknown-warning-option"
+ ],[
+ ax_compiler_flags_test=""
+ ])
+
+ # Base flags
+ AX_APPEND_COMPILE_FLAGS([ dnl
+ -fno-strict-aliasing dnl
+ $3 dnl
+ ],ax_warn_cxxflags_variable,[$ax_compiler_flags_test])
+
+ AS_IF([test "$ax_enable_compile_warnings" != "no"],[
+ # "yes" flags
+ AX_APPEND_COMPILE_FLAGS([ dnl
+ -Wall dnl
+ -Wextra dnl
+ -Wundef dnl
+ -Wwrite-strings dnl
+ -Wpointer-arith dnl
+ -Wmissing-declarations dnl
+ -Wredundant-decls dnl
+ -Wno-unused-parameter dnl
+ -Wno-missing-field-initializers dnl
+ -Wformat=2 dnl
+ -Wcast-align dnl
+ -Wformat-nonliteral dnl
+ -Wformat-security dnl
+ -Wsign-compare dnl
+ -Wstrict-aliasing dnl
+ -Wshadow dnl
+ -Winline dnl
+ -Wpacked dnl
+ -Wmissing-format-attribute dnl
+ -Wmissing-noreturn dnl
+ -Winit-self dnl
+ -Wredundant-decls dnl
+ -Wmissing-include-dirs dnl
+ -Wunused-but-set-variable dnl
+ -Warray-bounds dnl
+ -Wreturn-type dnl
+ -Wno-overloaded-virtual dnl
+ -Wswitch-enum dnl
+ -Wswitch-default dnl
+ $4 dnl
+ $5 dnl
+ $6 dnl
+ $7 dnl
+ ],ax_warn_cxxflags_variable,[$ax_compiler_flags_test])
+ ])
+ AS_IF([test "$ax_enable_compile_warnings" = "error"],[
+ # "error" flags; -Werror has to be appended unconditionally because
+ # it's not possible to test for
+ #
+ # suggest-attribute=format is disabled because it gives too many false
+ # positives
+ AX_APPEND_FLAG([-Werror],ax_warn_cxxflags_variable)
+
+ AX_APPEND_COMPILE_FLAGS([ dnl
+ -Wno-suggest-attribute=format dnl
+ ],ax_warn_cxxflags_variable,[$ax_compiler_flags_test])
+ ])
+
+ # In the flags below, when disabling specific flags, always add *both*
+ # -Wno-foo and -Wno-error=foo. This fixes the situation where (for example)
+ # we enable -Werror, disable a flag, and a build bot passes CXXFLAGS=-Wall,
+ # which effectively turns that flag back on again as an error.
+ for flag in $ax_warn_cxxflags_variable; do
+ AS_CASE([$flag],
+ [-Wno-*=*],[],
+ [-Wno-*],[
+ AX_APPEND_COMPILE_FLAGS([-Wno-error=$(AS_ECHO([$flag]) | $SED 's/^-Wno-//')],
+ ax_warn_cxxflags_variable,
+ [$ax_compiler_flags_test])
+ ])
+ done
+
+ AC_LANG_POP([C++])
+
+ # Substitute the variables
+ AC_SUBST(ax_warn_cxxflags_variable)
+])dnl AX_COMPILER_FLAGS_CXXFLAGS
+
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_gir.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_COMPILER_FLAGS_GIR([VARIABLE], [IS-RELEASE], [EXTRA-BASE-FLAGS], [EXTRA-YES-FLAGS])
+#
+# DESCRIPTION
+#
+# Add warning flags for the g-ir-scanner (from GObject Introspection) to
+# VARIABLE, which defaults to WARN_SCANNERFLAGS. VARIABLE is AC_SUBST-ed
+# by this macro, but must be manually added to the SCANNERFLAGS variable
+# for each GIR target in the code base.
+#
+# This macro depends on the environment set up by AX_COMPILER_FLAGS.
+# Specifically, it uses the value of $ax_enable_compile_warnings to decide
+# which flags to enable.
+#
+# LICENSE
+#
+# Copyright (c) 2015 Philip Withnall <philip@tecnocode.co.uk>
+#
+# 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 4
+
+AC_DEFUN([AX_COMPILER_FLAGS_GIR],[
+ AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+
+ # Variable names
+ m4_define(ax_warn_scannerflags_variable,
+ [m4_normalize(ifelse([$1],,[WARN_SCANNERFLAGS],[$1]))])
+
+ # Base flags
+ AX_APPEND_FLAG([$3],ax_warn_scannerflags_variable)
+
+ AS_IF([test "$ax_enable_compile_warnings" != "no"],[
+ # "yes" flags
+ AX_APPEND_FLAG([ dnl
+ --warn-all dnl
+ $4 dnl
+ $5 dnl
+ $6 dnl
+ $7 dnl
+ ],ax_warn_scannerflags_variable)
+ ])
+ AS_IF([test "$ax_enable_compile_warnings" = "error"],[
+ # "error" flags
+ AX_APPEND_FLAG([ dnl
+ --warn-error dnl
+ ],ax_warn_scannerflags_variable)
+ ])
+
+ # Substitute the variables
+ AC_SUBST(ax_warn_scannerflags_variable)
+])dnl AX_COMPILER_FLAGS
+
+# =============================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_ldflags.html
+# =============================================================================
+#
+# SYNOPSIS
+#
+# AX_COMPILER_FLAGS_LDFLAGS([VARIABLE], [IS-RELEASE], [EXTRA-BASE-FLAGS], [EXTRA-YES-FLAGS])
+#
+# DESCRIPTION
+#
+# Add warning flags for the linker to VARIABLE, which defaults to
+# WARN_LDFLAGS. VARIABLE is AC_SUBST-ed by this macro, but must be
+# manually added to the LDFLAGS variable for each target in the code base.
+#
+# This macro depends on the environment set up by AX_COMPILER_FLAGS.
+# Specifically, it uses the value of $ax_enable_compile_warnings to decide
+# which flags to enable.
+#
+# LICENSE
+#
+# Copyright (c) 2014, 2015 Philip Withnall <philip@tecnocode.co.uk>
+#
+# 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 5
+
+AC_DEFUN([AX_COMPILER_FLAGS_LDFLAGS],[
+ AX_REQUIRE_DEFINED([AX_APPEND_LINK_FLAGS])
+ AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+ AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
+
+ # Variable names
+ m4_define(ax_warn_ldflags_variable,
+ [m4_normalize(ifelse([$1],,[WARN_LDFLAGS],[$1]))])
+
+ # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
+ # flags, otherwise they are always appended to the warn_ldflags variable,
+ # and Clang warns on them for every compilation unit.
+ # If this is passed to GCC, it will explode, so the flag must be enabled
+ # conditionally.
+ AX_CHECK_COMPILE_FLAG([-Werror=unknown-warning-option],[
+ ax_compiler_flags_test="-Werror=unknown-warning-option"
+ ],[
+ ax_compiler_flags_test=""
+ ])
+
+ # Base flags
+ AX_APPEND_LINK_FLAGS([ dnl
+ -Wl,--no-as-needed dnl
+ $3 dnl
+ ],ax_warn_ldflags_variable,[$ax_compiler_flags_test])
+
+ AS_IF([test "$ax_enable_compile_warnings" != "no"],[
+ # "yes" flags
+ AX_APPEND_LINK_FLAGS([$4 $5 $6 $7],
+ ax_warn_ldflags_variable,
+ [$ax_compiler_flags_test])
+ ])
+ AS_IF([test "$ax_enable_compile_warnings" = "error"],[
+ # "error" flags; -Werror has to be appended unconditionally because
+ # it's not possible to test for
+ #
+ # suggest-attribute=format is disabled because it gives too many false
+ # positives
+ AX_APPEND_LINK_FLAGS([ dnl
+ -Wl,--fatal-warnings dnl
+ ],ax_warn_ldflags_variable,[$ax_compiler_flags_test])
+ ])
+
+ # Substitute the variables
+ AC_SUBST(ax_warn_ldflags_variable)
+])dnl AX_COMPILER_FLAGS
+
# longlong.m4 serial 17
dnl Copyright (C) 1999-2007, 2009-2015 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation