X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;f=m4%2Fax_harden_compiler_flags.m4;h=8ceeca67a52f48d263367c8458e37b32eefadd25;hb=22da6f6d6410053ac1f4682453b52463e6c9a05f;hp=247665caf8f5de88fea94133a343c50c7d23fa60;hpb=0aaa4448e3787c60c7ed87bd75905ca22ccec7a4;p=awesomized%2Flibmemcached

diff --git a/m4/ax_harden_compiler_flags.m4 b/m4/ax_harden_compiler_flags.m4
index 247665ca..8ceeca67 100644
--- a/m4/ax_harden_compiler_flags.m4
+++ b/m4/ax_harden_compiler_flags.m4
@@ -1,41 +1,37 @@
+# vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 # ===========================================================================
 #      https://github.com/BrianAker/ddm4/
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_HARDEN_COMPILER_FLAGS()
-#   AX_HARDEN_LINKER_FLAGS()
-#   AX_HARDEN_CC_COMPILER_FLAGS()
-#   AX_HARDEN_CXX_COMPILER_FLAGS()
+#   AX_HARDEN_COMPILER_FLAGS() AX_HARDEN_LINKER_FLAGS()
 #
 # DESCRIPTION
 #
 #   Any compiler flag that "hardens" or tests code. C99 is assumed.
 #
-#   NOTE: Implementation based on AX_APPEND_FLAG.
-#
 # LICENSE
 #
-#  Copyright (C) 2012 Brian Aker
+#  Copyright (C) 2012-2019 Brian Aker
 #  All rights reserved.
-#  
+#
 #  Redistribution and use in source and binary forms, with or without
 #  modification, are permitted provided that the following conditions are
 #  met:
-#  
+#
 #      * Redistributions of source code must retain the above copyright
 #  notice, this list of conditions and the following disclaimer.
-#  
+#
 #      * Redistributions in binary form must reproduce the above
 #  copyright notice, this list of conditions and the following disclaimer
 #  in the documentation and/or other materials provided with the
 #  distribution.
-#  
+#
 #      * The names of its contributors may not be used to endorse or
 #  promote products derived from this software without specific prior
 #  written permission.
-#  
+#
 #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 #  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 #  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
@@ -47,225 +43,312 @@
 #  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 #  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 #  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+#  Notes:
+#  We do not test for c99 or c++11, that is out of scope.
 
 # The Following flags are not checked for
 # -Wdeclaration-after-statement is counter to C99
-# AX_APPEND_COMPILE_FLAGS([-std=c++11]) -- Not ready yet
-# AX_APPEND_COMPILE_FLAGS([-pedantic]) -- ?
-# AX_APPEND_COMPILE_FLAGS([-Wstack-protector]) -- Issues on 32bit compile
-# AX_APPEND_COMPILE_FLAGS([-fstack-protector-all]) -- Issues on 32bit compile
-# AX_APPEND_COMPILE_FLAGS([-Wlong-long]) -- Don't turn on for compatibility issues memcached_stat_st
+# _APPEND_COMPILE_FLAGS_ERROR([-pedantic])
+
+#serial 17
+
+AC_DEFUN([_SET_SANITIZE_FLAGS],
+         [AS_IF([test "x$MINGW" != xyes],[
+                AS_IF([test "x$enable_shared" = "xyes"],
+                      [AS_CASE([$ax_harden_sanitize],
+                               [thread],[
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=thread])],
+                               [address],[
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=address])],
+                               [rest],[
+                               _APPEND_COMPILE_FLAGS_ERROR([-fno-omit-frame-pointer])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=integer])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=memory])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=alignment])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=bool])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=bounds])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=enum])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=float-cast-overflow])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=float-divide-by-zero])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=integer-divide-by-zero])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=null])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=return])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=shift])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=signed-integer-overflow])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=unreachable])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=unsigned-integer-overflow])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=vla-bound])
+                               _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=vptr])
+                               AS_IF([test "$ax_cv_c_compiler_vendor" != "clang"],[
+                                 _APPEND_COMPILE_FLAGS_ERROR([-fsanitize=object-size])
+                               ])
+                               ])
+                      ])
+                ])
+          ])
 
-#serial 5
+# Note: Should this be LIBS or LDFLAGS?
+AC_DEFUN([_APPEND_LINK_FLAGS_ERROR],
+         [AX_APPEND_LINK_FLAGS([$1],[LDFLAGS],[-Werror])
+         ])
 
-AC_DEFUN([AX_HARDEN_LINKER_FLAGS],
-    [AC_PREREQ([2.63])dnl
-    AC_REQUIRE([AX_CHECK_LINK_FLAG])
-    AC_REQUIRE([AX_VCS_CHECKOUT])
-    AC_REQUIRE([AX_DEBUG])
-    AC_REQUIRE([AX_CXX_COMPILER_VERSION])
+AC_DEFUN([_APPEND_COMPILE_FLAGS_ERROR],
+         [AX_APPEND_COMPILE_FLAGS([$1],,[-Werror])
+         ])
 
-    dnl If we are inside of VCS we append -Werror, otherwise we just use it to test other flags
-    AX_HARDEN_LIB=
-    ax_append_compile_link_flags_extra=
-    AS_IF([test "x$ac_cv_vcs_checkout" = "xyes"],
-      [AX_CHECK_LINK_FLAG([-Werror],
-        [AX_HARDEN_LIB="-Werror $AX_HARDEN_LIB"])
-      ],
-      [AX_CHECK_LINK_FLAG([-Werror],[
-        ax_append_compile_link_flags_extra='-Werror'
+# Everything above this does the heavy lifting, while what follows does the specifics.
+
+AC_DEFUN([_HARDEN_LINKER_FLAGS],
+        [AS_IF([test "$ax_cv_c_compiler_vendor" != "clang"],
+          [_APPEND_LINK_FLAGS_ERROR(["-z relro" "-z now"])
+          AS_IF([test "x$ac_cv_vcs_checkout" = xyes],
+          [_APPEND_LINK_FLAGS_ERROR([-rdynamic])
+#         AX_APPEND_LINK_FLAGS([--coverage])])
+          AS_IF([test "x$ac_cv_warnings_as_errors" = xyes],[AX_APPEND_LINK_FLAGS([-Werror])])
+          ])
         ])
-      ])
 
-    AX_CHECK_LINK_FLAG([-z relro -z now],
-      [AX_HARDEN_LIB="-z relro -z now $AX_HARDEN_LIB"],,
-      [$ax_append_compile_link_flags_extra])
+AC_DEFUN([_AX_HARDEN_SANITIZE],
+         [AC_REQUIRE([AX_DEBUG])
+         AC_ARG_WITH([sanitize],
+                     [AS_HELP_STRING([--with-sanitize],
+                                     [Enable sanitize flag for compiler if it supports them @<:@default=no@:>@])],
+                     [AS_CASE([$with_sanitize],
+                              [thread],[
+                              ax_harden_sanitize='thread'],
+                              [address],[
+                              ax_harden_sanitize='address'],
+                              [ax_harden_sanitize='rest'])
+                     ],
+                     [AS_IF([test "x$ax_enable_debug" = xyes],[ax_harden_sanitize='rest'])])
+         ])
+
+AC_DEFUN([_HARDEN_CC_COMPILER_FLAGS],
+         [AC_LANG_PUSH([C])dnl
 
-    AX_CHECK_LINK_FLAG([-pie],
-        [AX_HARDEN_LIB="-pie $AX_HARDEN_LIB"],,
-        [$ax_append_compile_link_flags_extra])
+         AS_IF([test "x$ax_enable_debug" = xyes],
+           [
+           #_APPEND_COMPILE_FLAGS_ERROR([-H])
+           _APPEND_COMPILE_FLAGS_ERROR([-g])
+           _APPEND_COMPILE_FLAGS_ERROR([-g3])
+           _APPEND_COMPILE_FLAGS_ERROR([-fno-eliminate-unused-debug-types])
+           _APPEND_COMPILE_FLAGS_ERROR([-fno-omit-frame-pointer])
+           ],[
+           _APPEND_COMPILE_FLAGS_ERROR([-g])
+           _APPEND_COMPILE_FLAGS_ERROR([-O2])
+           ])
 
-    LIB="$LIB $AX_HARDEN_LIB"
-    ])
+         AS_IF([test "x$ac_cv_vcs_checkout" = xyes],
+           [_APPEND_COMPILE_FLAGS_ERROR([-fstack-check])
+#          _APPEND_COMPILE_FLAGS_ERROR([--coverage])
+           _APPEND_COMPILE_FLAGS_ERROR([-Wpragmas])
+           _APPEND_COMPILE_FLAGS_ERROR([-Wunknown-pragmas])],
+           [_APPEND_COMPILE_FLAGS_ERROR([-Wno-unknown-pragmas])
+           _APPEND_COMPILE_FLAGS_ERROR([-Wno-pragmas])])
 
-      AC_DEFUN([AX_HARDEN_CC_COMPILER_FLAGS],
-          [AC_PREREQ([2.63])dnl
-          AC_REQUIRE([AX_APPEND_COMPILE_FLAGS])
-          AC_REQUIRE([AX_HARDEN_LINKER_FLAGS])
+         AS_IF([test "$ax_cv_c_compiler_vendor" = "clang"],[_APPEND_COMPILE_FLAGS_ERROR([-Qunused-arguments])])
 
-          AC_LANG_PUSH([C])
+         _APPEND_COMPILE_FLAGS_ERROR([-Wall])
+         _APPEND_COMPILE_FLAGS_ERROR([-Wextra])
+         _APPEND_COMPILE_FLAGS_ERROR([-Weverything])
+         _APPEND_COMPILE_FLAGS_ERROR([-Wthis-test-should-fail])
+# Anything below this comment please keep sorted.
+# _APPEND_COMPILE_FLAGS_ERROR([-Wmissing-format-attribute])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wno-attributes])
+          _APPEND_COMPILE_FLAGS_ERROR([-Waddress])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wvarargs])
+          _APPEND_COMPILE_FLAGS_ERROR([-Warray-bounds])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wbad-function-cast])
+# Not in use -Wc++-compat
+          _APPEND_COMPILE_FLAGS_ERROR([-Wchar-subscripts])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wcomment])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wfloat-equal])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wformat-security])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wformat=2])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wformat-y2k])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wmissing-field-initializers])
+          AS_IF([test "x$MINGW" = xyes],
+                [_APPEND_COMPILE_FLAGS_ERROR([-Wno-missing-noreturn])],
+                [_APPEND_COMPILE_FLAGS_ERROR([-Wmissing-noreturn])])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wmissing-prototypes])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wnested-externs])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wpointer-arith])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wpointer-sign])
+          AS_IF([test "x$MINGW" = xyes],
+                [_APPEND_COMPILE_FLAGS_ERROR([-Wno-suggest-attribute=const])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-suggest-attribute=noreturn])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-suggest-attribute=pure])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-redundant-decls])],
+                [_APPEND_COMPILE_FLAGS_ERROR([-Wredundant-decls])])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wshadow])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wshorten-64-to-32])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wsign-compare])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wstrict-overflow=1])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wstrict-prototypes])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wswitch-enum])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wundef])
 
-          ac_cv_warnings_as_errors=no
-          ax_append_compile_cflags_extra=
-          AS_IF([test "$ac_cv_vcs_checkout" = "yes"],[
-            AX_APPEND_COMPILE_FLAGS([-Werror])
-            ac_cv_warnings_as_errors=yes
-            ],[
-            AX_APPEND_COMPILE_FLAGS([-Werror],[ax_append_compile_cflags_extra])
-            ])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-result])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-variable])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-parameter])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-local-typedefs])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wwrite-strings])
+          _APPEND_COMPILE_FLAGS_ERROR([-fwrapv])
+          _APPEND_COMPILE_FLAGS_ERROR([-fmudflapt])
+          _APPEND_COMPILE_FLAGS_ERROR([-pipe])
+          AS_IF([test "x$MINGW" = xyes],
+                [],
+                [_APPEND_COMPILE_FLAGS_ERROR([-fPIE -pie])])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wsizeof-pointer-memaccess])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wpacked])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wlong-long])
+          _APPEND_COMPILE_FLAGS_ERROR([-ftrapv])
+          # Stop error when using -pie on library builds
+          _APPEND_COMPILE_FLAGS_ERROR([-Wno-unused-command-line-argument])
+#         GCC 4.5 removed this.
+#         _APPEND_COMPILE_FLAGS_ERROR([-Wunreachable-code])
 
-          AX_APPEND_COMPILE_FLAGS([-g])
-          AS_IF([test "$ax_enable_debug" = "yes"], [
-            AX_APPEND_COMPILE_FLAGS([-ggdb],,[$ax_append_compile_cflags_extra])
-            AX_APPEND_COMPILE_FLAGS([-O0],,[$ax_append_compile_cflags_extra])
-            ],[
-            AX_APPEND_COMPILE_FLAGS([-O2],,[$ax_append_compile_cflags_extra])
-            ])
+          _SET_SANITIZE_FLAGS
 
-  AX_APPEND_COMPILE_FLAGS([-fstack-check],,[$ax_append_compile_cflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wno-pragmas],,[$ax_append_compile_cflags_extra])
+          AS_IF([test "x$ax_enable_debug" = xno],
+            [AS_IF([test "x$ac_cv_vcs_checkout" = xyes],
+              [AS_IF([test "x${host_os}" != "xmingw"],
+                [AS_IF([test "x$ac_c_gcc_recent" = xyes],
+                  [_APPEND_COMPILE_FLAGS_ERROR([-D_FORTIFY_SOURCE=2])
+                  #_APPEND_COMPILE_FLAGS_ERROR([-Wstack-protector])
+                  #_APPEND_COMPILE_FLAGS_ERROR([-fstack-protector --param=ssp-buffer-size=4])
+                  _APPEND_COMPILE_FLAGS_ERROR([-fstack-protector-all])
+                  ])])])])
 
-  AX_APPEND_COMPILE_FLAGS([-Wall],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wextra],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunknown-pragmas],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wthis-test-should-fail],,[$ax_append_compile_cflags_extra])
-AX_APPEND_COMPILE_FLAGS([-std=c99],,[$ax_append_compile_cflags_extra])
-  dnl Anything below this comment please keep sorted.
-AX_APPEND_COMPILE_FLAGS([--param=ssp-buffer-size=1],,[$ax_append_compile_cflags_extra])
-  dnl -Wmissing-format-attribute
-  AX_APPEND_COMPILE_FLAGS([-Wno-attributes],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Waddress],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Warray-bounds],,[$ax_append_compile_cflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wbad-function-cast],,[$ax_append_compile_cflags_extra])
-  dnl Not in use -Wc++-compat
-  AX_APPEND_COMPILE_FLAGS([-Wchar-subscripts],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wcomment],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wfloat-equal],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wformat-security],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wformat=2],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wlogical-op],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wmaybe-uninitialized],,[$ax_append_compile_cflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wmissing-field-initializers],,[$ax_append_compile_cflags_extra])
-  AS_IF([test "$MINGW" = "yes"],[
-      AX_APPEND_COMPILE_FLAGS([-Wno-missing-noreturn],,[$ax_append_compile_cflags_extra])
-      ],[
-      AX_APPEND_COMPILE_FLAGS([-Wmissing-noreturn],,[$ax_append_compile_cflags_extra])
-      ])
-  AX_APPEND_COMPILE_FLAGS([-Wmissing-prototypes],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wnested-externs],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wnormalized=id],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wold-style-definition],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Woverride-init],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wpointer-sign],,[$ax_append_compile_cflags_extra])
-  AS_IF([test "$MINGW" = "yes"],[
-      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=const],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=noreturn],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=pure],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-redundant-decls],,[$ax_append_compile_cflags_extra])
-      ],[
-      AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cflags_extra])
-      ])
-  AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wstrict-prototypes],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wswitch-enum],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wundef],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunused],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunused-result],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunused-variable],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wwrite-strings],,[$ax_append_compile_cflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-floop-parallelize-all],,[$ax_append_compile_cflags_extra])
-AX_APPEND_COMPILE_FLAGS([-fwrapv],,[$ax_append_compile_cflags_extra])
-  AC_LANG_POP
+         AS_IF([test "x$ac_cv_warnings_as_errors" = xyes],
+             [AX_APPEND_COMPILE_FLAGS([-Werror])])
+
+          AC_LANG_POP([C])
   ])
 
-  AC_DEFUN([AX_HARDEN_CXX_COMPILER_FLAGS],
-      [AC_PREREQ([2.63])dnl
-      AC_REQUIRE([AX_HARDEN_CC_COMPILER_FLAGS])
-      AC_LANG_PUSH([C++])
+AC_DEFUN([_HARDEN_CXX_COMPILER_FLAGS],
+         [AC_LANG_PUSH([C++])
+         AS_IF([test "x$ax_enable_debug" = xyes],
+           [CXXFLAGS=''
+           #_APPEND_COMPILE_FLAGS_ERROR([-H])
+           _APPEND_COMPILE_FLAGS_ERROR([-g])
+           _APPEND_COMPILE_FLAGS_ERROR([-g3])
+           _APPEND_COMPILE_FLAGS_ERROR([-fno-inline])
+           _APPEND_COMPILE_FLAGS_ERROR([-fno-eliminate-unused-debug-types])
+           _APPEND_COMPILE_FLAGS_ERROR([-fno-omit-frame-pointer])
+           ],[
+           _APPEND_COMPILE_FLAGS_ERROR([-g])
+           _APPEND_COMPILE_FLAGS_ERROR([-O2])
+           ])
 
-      ax_append_compile_cxxflags_extra=
-      AS_IF([test "$ac_cv_warnings_as_errors" = "yes"],[
-        AX_APPEND_COMPILE_FLAGS([-Werror])
-        ],[
-        AX_APPEND_COMPILE_FLAGS([-Werror],[ax_append_compile_cxxflags_extra])
-        ])
+         AS_IF([test "x$ac_cv_vcs_checkout" = xyes],
+           [_APPEND_COMPILE_FLAGS_ERROR([-fstack-check])
+#          _APPEND_COMPILE_FLAGS_ERROR([--coverage])
+           _APPEND_COMPILE_FLAGS_ERROR([-Wpragmas])
+           _APPEND_COMPILE_FLAGS_ERROR([-Wunknown-pragmas])],
+           [_APPEND_COMPILE_FLAGS_ERROR([-Wno-unknown-pragmas])
+           _APPEND_COMPILE_FLAGS_ERROR([-Wno-pragmas])])
 
-      AX_APPEND_COMPILE_FLAGS([-g],,[$ax_append_compile_cxxflags_extra])
-      AS_IF([test "$ax_enable_debug" = "yes"], [
-        AX_APPEND_COMPILE_FLAGS([-O0],,[$ax_append_compile_cxxflags_extra])
-        AX_APPEND_COMPILE_FLAGS([-ggdb],,[$ax_append_compile_cxxflags_extra])
-        ],[
-        AX_APPEND_COMPILE_FLAGS([-O2],,[$ax_append_compile_cxxflags_extra])
-        AX_APPEND_COMPILE_FLAGS([-D_FORTIFY_SOURCE=2],,[$ax_append_compile_cxxflags_extra])
-        ])
+         AS_IF([test "$ax_cv_c_compiler_vendor" = "clang"],[_APPEND_COMPILE_FLAGS_ERROR([-Qunused-arguments])])
+
+         _APPEND_COMPILE_FLAGS_ERROR([-Wall])
+         _APPEND_COMPILE_FLAGS_ERROR([-Wextra])
+         _APPEND_COMPILE_FLAGS_ERROR([-Weverything])
+         _APPEND_COMPILE_FLAGS_ERROR([-Wthis-test-should-fail])
+# Anything below this comment please keep sorted.
+# _APPEND_COMPILE_FLAGS_ERROR([-Wmissing-format-attribute])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wno-attributes])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wvarargs])
+          _APPEND_COMPILE_FLAGS_ERROR([-Waddress])
+          _APPEND_COMPILE_FLAGS_ERROR([-Warray-bounds])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wchar-subscripts])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wcomment])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wctor-dtor-privacy])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wfloat-equal])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wformat=2])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wformat-y2k])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wmaybe-uninitialized])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wmissing-field-initializers])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wlogical-op])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wnon-virtual-dtor])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wnormalized=id])
+          _APPEND_COMPILE_FLAGS_ERROR([-Woverloaded-virtual])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wpointer-arith])
+          AS_IF([test "x$MINGW" = xyes],
+                [_APPEND_COMPILE_FLAGS_ERROR([-Wno-suggest-attribute=const])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-missing-noreturn])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wmissing-noreturn])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-suggest-attribute=noreturn])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-error=suggest-attribute=noreturn])
+                _APPEND_COMPILE_FLAGS_ERROR([-Wno-redundant-decls])],
+                [_APPEND_COMPILE_FLAGS_ERROR([-Wredundant-decls])])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wshadow])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wshorten-64-to-32])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wsign-compare])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wstrict-overflow=1])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wswitch-enum])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wtrampolines])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wundef])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunsafe-loop-optimizations])
+          _APPEND_COMPILE_FLAGS_ERROR([-funsafe-loop-optimizations])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wc++11-compat])
+# Disabled due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55837
+#          _APPEND_COMPILE_FLAGS_ERROR([-Weffc++])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wold-style-cast])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wclobbered])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-result])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-variable])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-parameter])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wunused-local-typedefs])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wwrite-strings])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wformat-security])
+          _APPEND_COMPILE_FLAGS_ERROR([-fwrapv])
+          _APPEND_COMPILE_FLAGS_ERROR([-fmudflapt])
+          _APPEND_COMPILE_FLAGS_ERROR([-pipe])
+          AS_IF([test "x$MINGW" = xyes],
+                [],
+                [_APPEND_COMPILE_FLAGS_ERROR([-fPIE -pie])])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wsizeof-pointer-memaccess])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wpacked])
+          _APPEND_COMPILE_FLAGS_ERROR([-Wlong-long])
+#         GCC 4.5 removed this.
+#         _APPEND_COMPILE_FLAGS_ERROR([-Wunreachable-code])
 
-  AS_IF([test "$ac_cv_vcs_checkout" = "yes"], [
-      AX_APPEND_COMPILE_FLAGS([-Werror],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-fstack-check],,[$ax_append_compile_cxxflags_extra])
-      ],[
-      AX_APPEND_COMPILE_FLAGS([-Wno-pragmas],,[$ax_append_compile_cxxflags_extra])
-      ])
+          AS_IF([test "x$ax_enable_debug" = xno],
+          [AS_IF([test "x$ac_cv_vcs_checkout" = xyes],
+            [AS_IF([test "x${host_os}" != "xmingw"],
+              [AS_IF([test "x$ac_c_gcc_recent" = xyes],
+                [_APPEND_COMPILE_FLAGS_ERROR([-D_FORTIFY_SOURCE=2])
+                #_APPEND_COMPILE_FLAGS_ERROR([-Wstack-protector])
+                #_APPEND_COMPILE_FLAGS_ERROR([-fstack-protector --param=ssp-buffer-size=4])
+                _APPEND_COMPILE_FLAGS_ERROR([-fstack-protector-all])
+                ])])])])
 
-  AX_APPEND_COMPILE_FLAGS([-Wall],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wextra],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunknown-pragmas],,[$ax_append_compile_cxxflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wthis-test-should-fail],,[$ax_append_compile_cxxflags_extra])
-  dnl Anything below this comment please keep sorted.
-AX_APPEND_COMPILE_FLAGS([--param=ssp-buffer-size=1],,[$ax_append_compile_cxxflags_extra])
-  dnl -Wmissing-format-attribute
-  AX_APPEND_COMPILE_FLAGS([-Wno-attributes],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Waddress],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Warray-bounds],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wchar-subscripts],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wcomment],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wctor-dtor-privacy],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wfloat-equal],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wformat=2],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wmaybe-uninitialized],,[$ax_append_compile_cxxflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wmissing-field-initializers],,[$ax_append_compile_cxxflags_extra])
-  AS_IF([test "$MINGW" = "yes"],[
-      AX_APPEND_COMPILE_FLAGS([-Wno-missing-noreturn],,[$ax_append_compile_cxxflags_extra])
-      ],[
-      AX_APPEND_COMPILE_FLAGS([-Wmissing-noreturn],,[$ax_append_compile_cxxflags_extra])
-      ])
-  AX_APPEND_COMPILE_FLAGS([-Wlogical-op],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wnon-virtual-dtor],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wnormalized=id],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Woverloaded-virtual],,[$ax_append_compile_cxxflags_extra])
-AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cxxflags_extra])
-  AS_IF([test "$MINGW" = "yes"],[
-      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=const],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=noreturn],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-error=suggest-attribute=noreturn],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-redundant-decls],,[$ax_append_compile_cxxflags_extra])
-      ],[
-      AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cxxflags_extra])
-      ])
-  AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wswitch-enum],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wundef],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wc++11-compat],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunused],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunused-result],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wunused-variable],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wwrite-strings],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-Wformat-security],,[$ax_append_compile_cxxflags_extra])
-  AX_APPEND_COMPILE_FLAGS([-floop-parallelize-all],,[$ax_append_compile_cxxflags_extra])
-AX_APPEND_COMPILE_FLAGS([-fwrapv],,[$ax_append_compile_cxxflags_extra])
-  AC_LANG_POP
+          _SET_SANITIZE_FLAGS
+
+          AS_IF([test "x$ac_cv_warnings_as_errors" = xyes],
+                [AX_APPEND_COMPILE_FLAGS([-Werror])])
+          AC_LANG_POP([C++])
   ])
 
+# All of the heavy lifting happens in _HARDEN_LINKER_FLAGS,
+# _HARDEN_CC_COMPILER_FLAGS, _HARDEN_CXX_COMPILER_FLAGS
   AC_DEFUN([AX_HARDEN_COMPILER_FLAGS],
-      [AC_PREREQ([2.63])dnl
-      AC_REQUIRE([AX_HARDEN_CXX_COMPILER_FLAGS])
-      AC_REQUIRE([AX_CC_OTHER_FLAGS])
-      gl_VISIBILITY
-      AS_IF([test -n "$CFLAG_VISIBILITY"], [ CPPFLAGS="$CPPFLAGS $CFLAG_VISIBILITY" ])
-      ])
+           [AC_PREREQ([2.63])dnl
+           AC_REQUIRE([AC_CANONICAL_HOST])
+           AC_REQUIRE([AX_COMPILER_VERSION])
+           AC_REQUIRE([AX_DEBUG])
+           AC_REQUIRE([AX_ASSERT])
+           _AX_HARDEN_SANITIZE
+
+           AC_REQUIRE([gl_VISIBILITY])
+           AS_IF([test -n "$CFLAG_VISIBILITY"],[CPPFLAGS="$CPPFLAGS $CFLAG_VISIBILITY"])
 
-  AC_DEFUN([AX_CC_OTHER_FLAGS],
-      [AC_PREREQ([2.63])dnl
-      AC_REQUIRE([AX_APPEND_COMPILE_FLAGS])
-      AC_REQUIRE([AX_HARDEN_CC_COMPILER_FLAGS])
+           _HARDEN_LINKER_FLAGS
+           _HARDEN_CC_COMPILER_FLAGS
+           _HARDEN_CXX_COMPILER_FLAGS
+           ])
 
-      AC_LANG_PUSH([C])
-      AX_APPEND_COMPILE_FLAGS([-pipe],,[$ax_append_compile_cflags_extra])
-      AC_LANG_POP
-      ])