configure: Allow disabling workaround for TLS bug in old ARM gcc versions
Some toolchains (such as sysmobts 201705 one) containing the TLS bug on
old ARM gcc versions (<7.3.0) also crash if the initial workaround found
is aplied (CFLAGS="-mtls-dialect=gnu2"). In that scenario, let's provide
a way to disable the workaround (to avoid "ld" crashing) and warn the
user about requirement to build with -O0 to avoid runtime crashes.
Related: OS#4062
Related: SYS#4628
Change-Id: I04ff8c702eabcf4f6e7b59e11aece2744267cefe
diff --git a/m4/check_tls_gcc_arm_bug.m4 b/m4/check_tls_gcc_arm_bug.m4
index 73b3e95..cee20e6 100644
--- a/m4/check_tls_gcc_arm_bug.m4
+++ b/m4/check_tls_gcc_arm_bug.m4
@@ -27,3 +27,25 @@
AC_SUBST([TLS_GCC_ARM_BUG_CFLAGS])
AC_MSG_RESULT([$TLS_GCC_ARM_BUG_CFLAGS])
])
+
+# Allow disabling the check in order to workaround bug by letting user pass
+# CFLAGS="-O0" on toolchains that crash when "-mtls-dialect=gnu2" is used.
+# CFLAGS is updated with workaround if detection is enabled and workaround is needed.
+AC_DEFUN([ARG_ENABLE_DETECT_TLS_GCC_ARM_BUG], [
+ AC_ARG_ENABLE(detect_tls_gcc_arm_bug,
+ [AS_HELP_STRING(
+ [--disable-detect-tls-gcc-arm-bug],
+ [Disable detecting and applying workaround for TLS bug on ARM platform for GCC < 7.3.0]
+ )],
+ [detect_tls_gcc_arm_bug=$enableval], [detect_tls_gcc_arm_bug="yes"])
+ if test x"$detect_tls_gcc_arm_bug" = x"yes"; then
+ CHECK_TLS_GCC_ARM_BUG
+ if test "x$TLS_GCC_ARM_BUG_CFLAGS" != "x"; then
+ CFLAGS="$CFLAGS $TLS_GCC_ARM_BUG_CFLAGS"
+ AC_MSG_WARN([Applying workaround for TLS bug on ARM platform for GCC < 7.3.0
+ ($TLS_GCC_ARM_BUG_CFLAGS). On some toolchain versions, ld may
+ crash. In that case you must build with CFLAGS='-O0' and run
+ ./configure with --disable-detect-tls-gcc-arm-bug])
+ fi
+fi
+])