Add ThreadSanitizer support

Has to be enabled in build by --with TSAN.
Would make build fail unit tests and print many warnings about possible
race conditions. Not useful for production build, but useful for
debugging thread related problems in system tests.

bind.spec

@@ -31,6 +31,7 @@
 %else
 %bcond_with    UNITTEST
 %endif
+%bcond_with    TSAN
 
 %{?!bind_uid:  %global bind_uid  25}
 %{?!bind_gid:  %global bind_gid  25}
@@ -244,6 +245,9 @@ BuildRequires:  fstrm-devel protobuf-c-devel
 %endif
 # Needed to regenerate dig.1 manpage
 BuildRequires: docbook-style-xsl, libxslt
+%if %{with TSAN}
+BuildRequires: libtsan
+%endif
 
 %description
 BIND (Berkeley Internet Name Domain) is an implementation of the DNS
@@ -643,10 +647,15 @@ done
   cp -Tuav bin/tests "%{1}/bin/tests/" \
   cp -uv version "%{1}" \
 
-export CFLAGS="$CFLAGS $RPM_OPT_FLAGS"
+CFLAGS="$CFLAGS $RPM_OPT_FLAGS"
+%if %{with TSAN}
+  CFLAGS+=" -O1 -fsanitize=thread -fPIE -pie"
+%endif
+export CFLAGS
 export CPPFLAGS="$CPPFLAGS -DDIG_SIGCHASE"
 export STD_CDEFINES="$CPPFLAGS"
 
+
 sed -i -e \
 's/RELEASEVER=\(.*\)/RELEASEVER=\1-RedHat-%{version}-%{release}/' \
 version
@@ -850,6 +859,10 @@ sed -e "/^\s*include(/ d" -e 's/^-- use //' \
   eval "$(bash %{SOURCE48} -A "`pwd`/softhsm-tokens")"
 %endif
 
+%if %{with TSAN}
+export TSAN_OPTIONS="log_exe_name=true log_path=ThreadSanitizer exitcode=0"
+%endif
+
 %if %{with UNITTEST}
   pushd build
   make unit