Signed-off-by: Jonatan Schlag <jonatan.schlag(a)ipfire.org>
---
Makefile.am | 3 +-
configure.ac | 15 +++++++
m4/warnings.m4 | 110 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 127 insertions(+), 1 deletion(-)
create mode 100644 m4/warnings.m4
diff --git a/Makefile.am b/Makefile.am
index 65e96d7..0c2f78c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -18,7 +18,8 @@ AM_CPPFLAGS = \
-DSYSCONFDIR=\""$(sysconfdir)"\" \
-I${top_srcdir}/src
-AM_CFLAGS = ${my_CFLAGS} \
+AM_CFLAGS = ${warn_CFLAGS} \
+ ${my_CFLAGS} \
-ffunction-sections \
-fdata-sections
diff --git a/configure.ac b/configure.ac
index 9eb9012..dd1ca64 100644
--- a/configure.ac
+++ b/configure.ac
@@ -89,6 +89,21 @@ AC_CHECK_FUNCS([ \
qsort \
])
+
+# - more-warnings --------------------------------------------------------------
+
+
+warn_CFLAGS=""
+
+AC_ARG_ENABLE([more_warnings],
+ AS_HELP_STRING([--enable-more-warnings], [enable more warn messages especially fanalyzer @<:@default=disabled@:>@]),
+ [more_warnings=yes], [more_warnings=no])
+AS_IF([test "x$more_warnings" = "xyes"],[
+ gl_WARN_ADD([-fanalyzer],[warn_CFLAGS])
+])
+
+AC_SUBST([warn_CFLAGS])
+
my_CFLAGS="\
-Wall \
-Wchar-subscripts \
diff --git a/m4/warnings.m4 b/m4/warnings.m4
new file mode 100644
index 0000000..9e24d89
--- /dev/null
+++ b/m4/warnings.m4
@@ -0,0 +1,110 @@
+# warnings.m4 serial 16
+dnl Copyright (C) 2008-2021 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_AS_VAR_APPEND(VAR, VALUE)
+# ----------------------------
+# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
+m4_ifdef([AS_VAR_APPEND],
+[m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])],
+[m4_define([gl_AS_VAR_APPEND],
+[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
+
+
+# gl_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED],
+# [PROGRAM = AC_LANG_PROGRAM()])
+# -----------------------------------------------------------------
+# Check if the compiler supports OPTION when compiling PROGRAM.
+#
+# The effects of this macro depend on the current language (_AC_LANG).
+AC_DEFUN([gl_COMPILER_OPTION_IF],
+[
+AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl
+AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl
+AS_LITERAL_IF([$1],
+ [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))],
+ [gl_positive="$1"
+case $gl_positive in
+ -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;;
+esac
+m4_pushdef([gl_Positive], [$gl_positive])])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], [gl_Warn], [
+ gl_save_compiler_FLAGS="$gl_Flags"
+ gl_AS_VAR_APPEND(m4_defn([gl_Flags]),
+ [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["])
+ AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([[]])])],
+ [AS_VAR_SET([gl_Warn], [yes])],
+ [AS_VAR_SET([gl_Warn], [no])])
+ gl_Flags="$gl_save_compiler_FLAGS"
+])
+AS_VAR_IF(gl_Warn, [yes], [$2], [$3])
+m4_popdef([gl_Positive])dnl
+AS_VAR_POPDEF([gl_Flags])dnl
+AS_VAR_POPDEF([gl_Warn])dnl
+])
+
+# gl_UNKNOWN_WARNINGS_ARE_ERRORS
+# ------------------------------
+# Clang doesn't complain about unknown warning options unless one also
+# specifies -Wunknown-warning-option -Werror. Detect this.
+#
+# The effects of this macro depend on the current language (_AC_LANG).
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS],
+[_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])
+
+# Specialization for _AC_LANG = C. This macro can be AC_REQUIREd.
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS(C)],
+[
+ AC_LANG_PUSH([C])
+ gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
+ AC_LANG_POP([C])
+])
+
+# Specialization for _AC_LANG = C++. This macro can be AC_REQUIREd.
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS(C++)],
+[
+ AC_LANG_PUSH([C++])
+ gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
+ AC_LANG_POP([C++])
+])
+
+# Specialization for _AC_LANG = Objective C. This macro can be AC_REQUIREd.
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS(Objective C)],
+[
+ AC_LANG_PUSH([Objective C])
+ gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
+ AC_LANG_POP([Objective C])
+])
+
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL],
+[gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option],
+ [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'],
+ [gl_unknown_warnings_are_errors=])])
+
+# gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS/WARN_CXXFLAGS],
+# [PROGRAM = AC_LANG_PROGRAM()])
+# -----------------------------------------------------------
+# Adds parameter to WARN_CFLAGS/WARN_CXXFLAGS if the compiler supports it
+# when compiling PROGRAM. For example, gl_WARN_ADD([-Wparentheses]).
+#
+# If VARIABLE is a variable name, AC_SUBST it.
+#
+# The effects of this macro depend on the current language (_AC_LANG).
+AC_DEFUN([gl_WARN_ADD],
+[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS(]_AC_LANG[)])
+gl_COMPILER_OPTION_IF([$1],
+ [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_]_AC_LANG_PREFIX[FLAGS]], [[$2]]), [" $1"])],
+ [],
+ [$3])
+m4_ifval([$2],
+ [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
+ [AC_SUBST([WARN_]_AC_LANG_PREFIX[FLAGS])])dnl
+])
+
+# Local Variables:
+# mode: autoconf
+# End:
--
2.30.1