sim: call SIM_AC_OPTION_WARNINGS(no) in remaining ports

We want all ports to opt into extra warnings as the default compiler
settings lets a lot slide.  Opt all the ports that haven't already in
to the warning system.  None of them build with -Werror, so disable
that by default.  Hopefully someone finds these important enough to
start fixing at some point.

30 files changed, 1130 insertions, 20 deletions

diff --git a/sim/bpf/ChangeLog b/sim/bpf/ChangeLog
index b08642f..24ed05e 100644
--- a/sim/bpf/ChangeLog
+++ b/sim/bpf/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 
 2021-01-09  Mike Frysinger  <vapier@gentoo.org>
diff --git a/sim/bpf/configure b/sim/bpf/configure
index cad42b2..52d64ce 100755
--- a/sim/bpf/configure
+++ b/sim/bpf/configure
@@ -788,6 +788,9 @@ enable_sim_endian
 enable_sim_alignment
 enable_sim_scache
 enable_sim_default_model
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cgen_maint
 '
       ac_precious_vars='build_alias
@@ -1448,6 +1451,11 @@ Optional Features:
                           Specify simulator execution cache size
   --enable-sim-default-model=model
                           Specify default model to simulate
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --enable-cgen-maint=DIR build cgen generated files
 
 Optional Packages:
@@ -12934,7 +12942,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12937 "configure"
+#line 12945 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13040,7 +13048,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13043 "configure"
+#line 13051 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13777,6 +13785,103 @@ fi
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 cgen_maint=no
 cgen=guile
 cgendir='$(srcdir)/../../cgen'
diff --git a/sim/bpf/configure.ac b/sim/bpf/configure.ac
index e7cd72a..e9df51a 100644
--- a/sim/bpf/configure.ac
+++ b/sim/bpf/configure.ac
@@ -9,6 +9,7 @@ SIM_AC_OPTION_ENDIAN([], [LITTLE])
 SIM_AC_OPTION_ALIGNMENT(NONSTRICT_ALIGNMENT)
 SIM_AC_OPTION_SCACHE(16384)
 SIM_AC_OPTION_DEFAULT_MODEL([bpf-def])
+SIM_AC_OPTION_WARNINGS(no)
 SIM_AC_OPTION_CGEN_MAINT
 
 SIM_AC_OUTPUT
diff --git a/sim/erc32/ChangeLog b/sim/erc32/ChangeLog
index d169de8..68599f7 100644
--- a/sim/erc32/ChangeLog
+++ b/sim/erc32/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* sis.c: Delete HAVE_STDLIB_H.
 
diff --git a/sim/erc32/configure b/sim/erc32/configure
index 360cffb..71558e1 100755
--- a/sim/erc32/configure
+++ b/sim/erc32/configure
@@ -782,6 +782,9 @@ enable_sim_environment
 enable_sim_inline
 with_pkgversion
 with_bugurl
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1431,6 +1434,11 @@ Optional Features:
                           environment
   --enable-sim-inline=inlines
                           Specify which functions should be inlined
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -12916,7 +12924,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12919 "configure"
+#line 12927 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13022,7 +13030,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13025 "configure"
+#line 13033 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13573,6 +13581,103 @@ _ACEOF
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 # In the Cygwin environment, we need some additional flags.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for cygwin" >&5
 $as_echo_n "checking for cygwin... " >&6; }
diff --git a/sim/erc32/configure.ac b/sim/erc32/configure.ac
index 2317d47..2c81b84 100644
--- a/sim/erc32/configure.ac
+++ b/sim/erc32/configure.ac
@@ -18,6 +18,7 @@ AC_INIT(Makefile.in)
 sinclude(../common/acinclude.m4)
 
 SIM_AC_COMMON
+SIM_AC_OPTION_WARNINGS(no)
 
 # In the Cygwin environment, we need some additional flags.
 AC_CACHE_CHECK([for cygwin], sim_cv_os_cygwin,
diff --git a/sim/frv/ChangeLog b/sim/frv/ChangeLog
index 9022879..5fa0362 100644
--- a/sim/frv/ChangeLog
+++ b/sim/frv/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* options.c, sim-if.c: Delete HAVE_STRING_H, HAVE_STRINGS_H,
 	HAVE_STDLIB_H, and strings.h include.
diff --git a/sim/frv/configure b/sim/frv/configure
index d10ca4b..dd0cf46 100755
--- a/sim/frv/configure
+++ b/sim/frv/configure
@@ -788,6 +788,9 @@ enable_sim_endian
 enable_sim_alignment
 enable_sim_scache
 enable_sim_default_model
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cgen_maint
 enable_sim_trapdump
 enable_sim_hardware
@@ -1449,6 +1452,11 @@ Optional Features:
                           Specify simulator execution cache size
   --enable-sim-default-model=model
                           Specify default model to simulate
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --enable-cgen-maint=DIR build cgen generated files
   --enable-sim-trapdump   Make unknown traps dump the registers
   --enable-sim-hardware=LIST
@@ -12938,7 +12946,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12941 "configure"
+#line 12949 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13044,7 +13052,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13047 "configure"
+#line 13055 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13722,6 +13730,103 @@ fi
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 cgen_maint=no
 cgen=guile
 cgendir='$(srcdir)/../../cgen'
diff --git a/sim/frv/configure.ac b/sim/frv/configure.ac
index cb3cc14..5588533 100644
--- a/sim/frv/configure.ac
+++ b/sim/frv/configure.ac
@@ -8,6 +8,7 @@ SIM_AC_OPTION_ENDIAN(BIG)
 SIM_AC_OPTION_ALIGNMENT(STRICT_ALIGNMENT)
 SIM_AC_OPTION_SCACHE(16384)
 SIM_AC_OPTION_DEFAULT_MODEL(fr500)
+SIM_AC_OPTION_WARNINGS(no)
 SIM_AC_OPTION_CGEN_MAINT
 
 #
diff --git a/sim/h8300/ChangeLog b/sim/h8300/ChangeLog
index f6dd484..1f9281f 100644
--- a/sim/h8300/ChangeLog
+++ b/sim/h8300/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* compile.c: Delete HAVE_TIME_H & HAVE_STDLIB_H.
 
diff --git a/sim/h8300/configure b/sim/h8300/configure
index 34c63bf..5254a36 100755
--- a/sim/h8300/configure
+++ b/sim/h8300/configure
@@ -782,6 +782,9 @@ with_pkgversion
 with_bugurl
 enable_sim_endian
 enable_sim_alignment
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1436,6 +1439,11 @@ Optional Features:
   --enable-sim-alignment=align
                           Specify strict, nonstrict or forced alignment of
                           memory accesses
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -12921,7 +12929,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12924 "configure"
+#line 12932 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13027,7 +13035,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13030 "configure"
+#line 13038 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13670,6 +13678,103 @@ fi
 fi
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 for ac_header in sys/param.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "sys/param.h" "ac_cv_header_sys_param_h" "$ac_includes_default"
diff --git a/sim/h8300/configure.ac b/sim/h8300/configure.ac
index d2ee926..8caacad 100644
--- a/sim/h8300/configure.ac
+++ b/sim/h8300/configure.ac
@@ -6,6 +6,7 @@ SIM_AC_COMMON
 
 SIM_AC_OPTION_ENDIAN(BIG)
 SIM_AC_OPTION_ALIGNMENT(NONSTRICT_ALIGNMENT)
+SIM_AC_OPTION_WARNINGS(no)
 
 AC_CHECK_HEADERS(sys/param.h)
 
diff --git a/sim/iq2000/ChangeLog b/sim/iq2000/ChangeLog
index 7346cbd..f609759 100644
--- a/sim/iq2000/ChangeLog
+++ b/sim/iq2000/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* sim-if.c: Delete HAVE_STDLIB_H.
 
diff --git a/sim/iq2000/configure b/sim/iq2000/configure
index d16aeee..cd7acea 100755
--- a/sim/iq2000/configure
+++ b/sim/iq2000/configure
@@ -787,6 +787,9 @@ enable_sim_endian
 enable_sim_alignment
 enable_sim_scache
 enable_sim_default_model
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cgen_maint
 enable_sim_hardware
 '
@@ -1447,6 +1450,11 @@ Optional Features:
                           Specify simulator execution cache size
   --enable-sim-default-model=model
                           Specify default model to simulate
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --enable-cgen-maint=DIR build cgen generated files
   --enable-sim-hardware=LIST
                           Specify the hardware to be included in the build.
@@ -12935,7 +12943,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12938 "configure"
+#line 12946 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13041,7 +13049,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13044 "configure"
+#line 13052 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13719,6 +13727,103 @@ fi
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 cgen_maint=no
 cgen=guile
 cgendir='$(srcdir)/../../cgen'
diff --git a/sim/iq2000/configure.ac b/sim/iq2000/configure.ac
index 6b9f363..4a1b28b 100644
--- a/sim/iq2000/configure.ac
+++ b/sim/iq2000/configure.ac
@@ -8,6 +8,7 @@ SIM_AC_OPTION_ENDIAN(BIG)
 SIM_AC_OPTION_ALIGNMENT(STRICT_ALIGNMENT)
 SIM_AC_OPTION_SCACHE(16384)
 SIM_AC_OPTION_DEFAULT_MODEL(iq2000)
+SIM_AC_OPTION_WARNINGS(no)
 SIM_AC_OPTION_CGEN_MAINT
 
 SIM_AC_OPTION_HARDWARE(yes,"","")
diff --git a/sim/lm32/ChangeLog b/sim/lm32/ChangeLog
index 4796212..0c93128 100644
--- a/sim/lm32/ChangeLog
+++ b/sim/lm32/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* sim-if.c: Delete HAVE_STDLIB_H.
 
diff --git a/sim/lm32/configure b/sim/lm32/configure
index fa59d92..8f5aae6 100755
--- a/sim/lm32/configure
+++ b/sim/lm32/configure
@@ -787,6 +787,9 @@ enable_sim_endian
 enable_sim_alignment
 enable_sim_scache
 enable_sim_default_model
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cgen_maint
 enable_sim_hardware
 '
@@ -1447,6 +1450,11 @@ Optional Features:
                           Specify simulator execution cache size
   --enable-sim-default-model=model
                           Specify default model to simulate
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --enable-cgen-maint=DIR build cgen generated files
   --enable-sim-hardware=LIST
                           Specify the hardware to be included in the build.
@@ -12935,7 +12943,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12938 "configure"
+#line 12946 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13041,7 +13049,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13044 "configure"
+#line 13052 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13719,6 +13727,103 @@ fi
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 cgen_maint=no
 cgen=guile
 cgendir='$(srcdir)/../../cgen'
diff --git a/sim/lm32/configure.ac b/sim/lm32/configure.ac
index 82240ff..7da76d9 100644
--- a/sim/lm32/configure.ac
+++ b/sim/lm32/configure.ac
@@ -8,6 +8,7 @@ SIM_AC_OPTION_ENDIAN(BIG)
 SIM_AC_OPTION_ALIGNMENT(STRICT_ALIGNMENT,STRICT_ALIGNMENT)
 SIM_AC_OPTION_SCACHE(16384)
 SIM_AC_OPTION_DEFAULT_MODEL(lm32)
+SIM_AC_OPTION_WARNINGS(no)
 SIM_AC_OPTION_CGEN_MAINT
 SIM_AC_OPTION_HARDWARE(yes,,lm32cpu lm32timer lm32uart)
 
diff --git a/sim/m32r/ChangeLog b/sim/m32r/ChangeLog
index dd4bba9..551e12b 100644
--- a/sim/m32r/ChangeLog
+++ b/sim/m32r/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* sim-if.c: Delete HAVE_STRING_H, HAVE_STRINGS_H, HAVE_STDLIB_H,
 	and strings.h include.
diff --git a/sim/m32r/configure b/sim/m32r/configure
index 5b73aa5..efcaed9 100755
--- a/sim/m32r/configure
+++ b/sim/m32r/configure
@@ -789,6 +789,9 @@ enable_sim_endian
 enable_sim_alignment
 enable_sim_scache
 enable_sim_default_model
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cgen_maint
 enable_sim_hardware
 '
@@ -1449,6 +1452,11 @@ Optional Features:
                           Specify simulator execution cache size
   --enable-sim-default-model=model
                           Specify default model to simulate
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --enable-cgen-maint=DIR build cgen generated files
   --enable-sim-hardware=LIST
                           Specify the hardware to be included in the build.
@@ -12937,7 +12945,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12940 "configure"
+#line 12948 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13043,7 +13051,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13046 "configure"
+#line 13054 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13721,6 +13729,103 @@ fi
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 cgen_maint=no
 cgen=guile
 cgendir='$(srcdir)/../../cgen'
diff --git a/sim/m32r/configure.ac b/sim/m32r/configure.ac
index 6020a5c..e74a8a5 100644
--- a/sim/m32r/configure.ac
+++ b/sim/m32r/configure.ac
@@ -8,6 +8,7 @@ SIM_AC_OPTION_ENDIAN(BIG)
 SIM_AC_OPTION_ALIGNMENT(STRICT_ALIGNMENT)
 SIM_AC_OPTION_SCACHE(16384)
 SIM_AC_OPTION_DEFAULT_MODEL(m32r/d)
+SIM_AC_OPTION_WARNINGS(no)
 SIM_AC_OPTION_CGEN_MAINT
 
   case "${target_alias}" in
diff --git a/sim/or1k/ChangeLog b/sim/or1k/ChangeLog
index 1b7e6e2..016ffd0 100644
--- a/sim/or1k/ChangeLog
+++ b/sim/or1k/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* sim-main.h: Include config.h.
 
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
diff --git a/sim/or1k/configure b/sim/or1k/configure
index 538011c..8d8746e 100755
--- a/sim/or1k/configure
+++ b/sim/or1k/configure
@@ -788,6 +788,9 @@ enable_sim_alignment
 enable_sim_bitsize
 enable_sim_scache
 enable_sim_default_model
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cgen_maint
 '
       ac_precious_vars='build_alias
@@ -1448,6 +1451,11 @@ Optional Features:
                           Specify simulator execution cache size
   --enable-sim-default-model=model
                           Specify default model to simulate
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --enable-cgen-maint=DIR build cgen generated files
 
 Optional Packages:
@@ -12934,7 +12942,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12937 "configure"
+#line 12945 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13040,7 +13048,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13043 "configure"
+#line 13051 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13777,6 +13785,103 @@ fi
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking default sim environment setting" >&5
 $as_echo_n "checking default sim environment setting... " >&6; }
 sim_environment="ALL_ENVIRONMENT"
diff --git a/sim/or1k/configure.ac b/sim/or1k/configure.ac
index aa7c400..19a1da3 100644
--- a/sim/or1k/configure.ac
+++ b/sim/or1k/configure.ac
@@ -9,6 +9,7 @@ SIM_AC_OPTION_ALIGNMENT(STRICT_ALIGNMENT)
 SIM_AC_OPTION_BITSIZE([32], [31], [32])
 SIM_AC_OPTION_SCACHE(16384)
 SIM_AC_OPTION_DEFAULT_MODEL([or1200])
+SIM_AC_OPTION_WARNINGS(no)
 SIM_AC_OPTION_ENVIRONMENT
 SIM_AC_OPTION_INLINE()
 SIM_AC_OPTION_CGEN_MAINT
diff --git a/sim/rl78/ChangeLog b/sim/rl78/ChangeLog
index ec31614..ddce236 100644
--- a/sim/rl78/ChangeLog
+++ b/sim/rl78/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* cpu.h (pc): Change to an extern.
 	* cpu.c (pc): Define.
 
diff --git a/sim/rl78/configure b/sim/rl78/configure
index 24de7d6..842091b 100755
--- a/sim/rl78/configure
+++ b/sim/rl78/configure
@@ -780,6 +780,9 @@ enable_sim_environment
 enable_sim_inline
 with_pkgversion
 with_bugurl
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1429,6 +1432,11 @@ Optional Features:
                           environment
   --enable-sim-inline=inlines
                           Specify which functions should be inlined
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -12914,7 +12922,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12917 "configure"
+#line 12925 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13020,7 +13028,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13023 "configure"
+#line 13031 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13571,6 +13579,103 @@ _ACEOF
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 for ac_header in getopt.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "getopt.h" "ac_cv_header_getopt_h" "$ac_includes_default"
diff --git a/sim/rl78/configure.ac b/sim/rl78/configure.ac
index b44d1da..65bb407 100644
--- a/sim/rl78/configure.ac
+++ b/sim/rl78/configure.ac
@@ -22,6 +22,7 @@ AC_INIT(Makefile.in)
 sinclude(../common/acinclude.m4)
 
 SIM_AC_COMMON
+SIM_AC_OPTION_WARNINGS(no)
 
 AC_CHECK_HEADERS(getopt.h)
 
diff --git a/sim/rx/ChangeLog b/sim/rx/ChangeLog
index 79b4e99..684c38a 100644
--- a/sim/rx/ChangeLog
+++ b/sim/rx/ChangeLog
@@ -1,5 +1,10 @@
 2021-01-11  Mike Frysinger  <vapier@gentoo.org>
 
+	* configure.ac: Call SIM_AC_OPTION_WARNINGS.
+	* configure: Regenerate.
+
+2021-01-11  Mike Frysinger  <vapier@gentoo.org>
+
 	* config.in, configure: Regenerate.
 	* main.c: Delete HAVE_STDLIB_H.
 
diff --git a/sim/rx/configure b/sim/rx/configure
index 447a252..3969c67 100755
--- a/sim/rx/configure
+++ b/sim/rx/configure
@@ -780,6 +780,9 @@ enable_sim_environment
 enable_sim_inline
 with_pkgversion
 with_bugurl
+enable_werror
+enable_build_warnings
+enable_sim_build_warnings
 enable_cycle_accurate
 enable_cycle_stats
 '
@@ -1431,6 +1434,11 @@ Optional Features:
                           environment
   --enable-sim-inline=inlines
                           Specify which functions should be inlined
+  --enable-werror         treat compile warnings as errors
+  --enable-build-warnings enable build-time compiler warnings if gcc is used
+  --enable-sim-build-warnings
+                          enable SIM specific build-time compiler warnings if
+                          gcc is used
   --disable-cycle-accurate
                           Disable cycle accurate simulation (faster runtime)
   --disable-cycle-stats   Disable cycle statistics (faster runtime)
@@ -12919,7 +12927,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 12922 "configure"
+#line 12930 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13025,7 +13033,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 13028 "configure"
+#line 13036 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13576,6 +13584,103 @@ _ACEOF
 
 
 
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror; case "${enableval}" in
+     yes | y) ERROR_ON_WARNING="yes" ;;
+     no | n)  ERROR_ON_WARNING="no" ;;
+     *) as_fn_error $? "bad value ${enableval} for --enable-werror" "$LINENO" 5 ;;
+   esac
+fi
+
+
+# Enable -Werror by default when using gcc
+if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" ; then
+    ERROR_ON_WARNING=yes
+fi
+
+WERROR_CFLAGS=""
+
+build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
+-Wpointer-sign \
+-Wno-unused -Wunused-value -Wunused-function \
+-Wno-switch -Wno-char-subscripts -Wmissing-prototypes
+-Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type \
+-Wold-style-declaration -Wold-style-definition"
+
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
+  *) build_warnings="$build_warnings -Wformat-nonliteral" ;;
+esac
+
+# Check whether --enable-build-warnings was given.
+if test "${enable_build_warnings+set}" = set; then :
+  enableval=$enable_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+# Check whether --enable-sim-build-warnings was given.
+if test "${enable_sim_build_warnings+set}" = set; then :
+  enableval=$enable_sim_build_warnings; case "${enableval}" in
+  yes)	;;
+  no)	build_warnings="-w";;
+  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${build_warnings} ${t}";;
+  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
+        build_warnings="${t} ${build_warnings}";;
+  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
+fi
+fi
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes
+then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking compiler warning flags" >&5
+$as_echo_n "checking compiler warning flags... " >&6; }
+    # Separate out the -Werror flag as some files just cannot be
+    # compiled with it enabled.
+    for w in ${build_warnings}; do
+	case $w in
+	-Werr*) WERROR_CFLAGS=-Werror ;;
+	*) # Check that GCC accepts it
+	    saved_CFLAGS="$CFLAGS"
+	    CFLAGS="$CFLAGS $w"
+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  WARN_CFLAGS="${WARN_CFLAGS} $w"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	    CFLAGS="$saved_CFLAGS"
+	esac
+    done
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
+$as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
+fi
+
+
 for ac_header in getopt.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "getopt.h" "ac_cv_header_getopt_h" "$ac_includes_default"
diff --git a/sim/rx/configure.ac b/sim/rx/configure.ac
index 1bdb5ab..6c14434 100644
--- a/sim/rx/configure.ac
+++ b/sim/rx/configure.ac
@@ -22,6 +22,7 @@ AC_INIT(Makefile.in)
 sinclude(../common/acinclude.m4)
 
 SIM_AC_COMMON
+SIM_AC_OPTION_WARNINGS(no)
 
 AC_CHECK_HEADERS(getopt.h)