configure: simplify warning flags detection

[babeltrace.git] / m4 / ax_compiler_flags_ldflags.m4

diff --git a/m4/ax_compiler_flags_ldflags.m4 b/m4/ax_compiler_flags_ldflags.m4
deleted file mode 100644 (file)
index 976d119..0000000
--- a/m4/ax_compiler_flags_ldflags.m4
+++ /dev/null
@@ -1,111 +0,0 @@
-# ==============================================================================
-#  https://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>
-#   Copyright (c) 2017, 2018 Reini Urban <rurban@cpan.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 9
-
-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])
-    AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
-
-    # Variable names
-    m4_define([ax_warn_ldflags_variable],
-              [m4_normalize(ifelse([$1],,[WARN_LDFLAGS],[$1]))])
-
-    # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
-    # flags, otherwise they are always appended to the warn_ldflags variable,
-    # and Clang warns on them for every compilation unit.
-    # If this is passed to GCC, it will explode, so the flag must be enabled
-    # conditionally.
-    AX_CHECK_COMPILE_FLAG([-Werror=unknown-warning-option],[
-        ax_compiler_flags_test="-Werror=unknown-warning-option"
-    ],[
-        ax_compiler_flags_test=""
-    ])
-
-    AX_CHECK_LINK_FLAG([-Wl,--as-needed], [
-        AX_APPEND_LINK_FLAGS([-Wl,--as-needed],
-          [AM_LDFLAGS],[$ax_compiler_flags_test])
-    ])
-    AX_CHECK_LINK_FLAG([-Wl,-z,relro], [
-        AX_APPEND_LINK_FLAGS([-Wl,-z,relro],
-          [AM_LDFLAGS],[$ax_compiler_flags_test])
-    ])
-    AX_CHECK_LINK_FLAG([-Wl,-z,now], [
-        AX_APPEND_LINK_FLAGS([-Wl,-z,now],
-          [AM_LDFLAGS],[$ax_compiler_flags_test])
-    ])
-    AX_CHECK_LINK_FLAG([-Wl,-z,noexecstack], [
-        AX_APPEND_LINK_FLAGS([-Wl,-z,noexecstack],
-          [AM_LDFLAGS],[$ax_compiler_flags_test])
-    ])
-    # textonly, retpolineplt not yet
-
-    # macOS and cygwin linker do not have --as-needed
-    AX_CHECK_LINK_FLAG([-Wl,--no-as-needed], [
-        ax_compiler_flags_as_needed_option="-Wl,--no-as-needed"
-    ], [
-        ax_compiler_flags_as_needed_option=""
-    ])
-
-    # macOS linker speaks with a different accent
-    ax_compiler_flags_fatal_warnings_option=""
-    AX_CHECK_LINK_FLAG([-Wl,--fatal-warnings], [
-        ax_compiler_flags_fatal_warnings_option="-Wl,--fatal-warnings"
-    ])
-    AX_CHECK_LINK_FLAG([-Wl,-fatal_warnings], [
-        ax_compiler_flags_fatal_warnings_option="-Wl,-fatal_warnings"
-    ])
-
-    # Base flags
-    AX_APPEND_LINK_FLAGS([ dnl
-        $ax_compiler_flags_as_needed_option 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
-            $ax_compiler_flags_fatal_warnings_option dnl
-        ],ax_warn_ldflags_variable,[$ax_compiler_flags_test])
-    ])
-
-    # Substitute the variables
-    AC_SUBST(ax_warn_ldflags_variable)
-])dnl AX_COMPILER_FLAGS