configure, meson: move config-poison.h to meson

This ensures that the file is regenerated properly whenever config-target.h
or config-devices.h files change.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Makefile

@@ -221,7 +221,7 @@ qemu-%.tar.bz2:
 
 distclean: clean
 	-$(quiet-@)test -f build.ninja && $(NINJA) $(NINJAFLAGS) -t clean -g || :
-	rm -f config-host.mak config-poison.h
+	rm -f config-host.mak
 	rm -f tests/tcg/config-*.mak
 	rm -f config.status
 	rm -f roms/seabios/config.mak

configure

@@ -3834,17 +3834,6 @@ if test -n "${deprecated_features}"; then
     echo "  features: ${deprecated_features}"
 fi
 
-# Create list of config switches that should be poisoned in common code...
-# but filter out CONFIG_TCG and CONFIG_USER_ONLY which are special.
-target_configs_h=$(ls *-config-devices.h *-config-target.h 2>/dev/null)
-if test -n "$target_configs_h" ; then
-    sed -n -e '/CONFIG_TCG/d' -e '/CONFIG_USER_ONLY/d' \
-        -e '/^#define / { s///; s/ .*//; s/^/#pragma GCC poison /p; }' \
-        $target_configs_h | sort -u > config-poison.h
-else
-    :> config-poison.h
-fi
-
 # Save the configure command line for later reuse.
 cat <<EOD >config.status
 #!/bin/sh

meson.build

@@ -2028,6 +2028,18 @@ config_all += {
   'CONFIG_ALL': true,
 }
 
+target_configs_h = []
+foreach target: target_dirs
+  target_configs_h += config_target_h[target]
+  target_configs_h += config_devices_h.get(target, [])
+endforeach
+genh += custom_target('config-poison.h',
+                      input: [target_configs_h],
+                      output: 'config-poison.h',
+                      capture: true,
+                      command: [find_program('scripts/make-config-poison.sh'),
+                                target_configs_h])
+
 ##############
 # Submodules #
 ##############

scripts/make-config-poison.sh

@@ -0,0 +1,16 @@
+#! /bin/sh
+
+if test $# = 0; then
+  exit 0
+fi
+
+# Create list of config switches that should be poisoned in common code...
+# but filter out CONFIG_TCG and CONFIG_USER_ONLY which are special.
+exec sed -n \
+  -e' /CONFIG_TCG/d' \
+  -e '/CONFIG_USER_ONLY/d' \
+  -e '/^#define / {' \
+  -e    's///' \
+  -e    's/ .*//' \
+  -e    's/^/#pragma GCC poison /p' \
+  -e '}' "$@"