qb: Check for a Qt5 moc. (#8029)

.gitignore

@@ -11,6 +11,8 @@
 .tmp
 .tmp.c
 .tmp.cxx
+.moc.h
+.moc.cpp
 config.log
 /.project
 /.externalToolBuilders/

qb/config.libs.sh

@@ -277,7 +277,7 @@ check_val '' SDL2 -lSDL2 SDL2
 
 check_enabled QT 'Qt companion'
 
-if [ "$HAVE_QT" != 'no' ] && [ "$MOC_PATH" != 'none' ]; then
+if [ "$HAVE_QT" != 'no' ] && [ "$HAVE_MOC" = 'yes' ]; then
    check_pkgconf QT5CORE Qt5Core 5.2
    check_pkgconf QT5GUI Qt5Gui 5.2
    check_pkgconf QT5WIDGETS Qt5Widgets 5.2
@@ -286,13 +286,7 @@ if [ "$HAVE_QT" != 'no' ] && [ "$MOC_PATH" != 'none' ]; then
    #check_pkgconf QT5WEBENGINE Qt5WebEngine 5.4
    check_pkgconf OPENSSL openssl 1.0.0
 
-   check_val '' QT5CORE -lQt5Core QT5CORE
-   check_val '' QT5GUI -lQt5Gui QT5GUI
-   check_val '' QT5WIDGETS -lQt5Widgets QT5WIDGETS
-   check_val '' QT5CONCURRENT -lQt5Concurrent QT5CONCURRENT
-   check_val '' QT5NETWORK -lQt5Network QT5NETWORK
-   #check_val '' QT5WEBENGINE -lQt5WebEngine QT5WEBENGINE
-   check_val '' OPENSSL -lssl OPENSSL
+   # pkg-config is needed to reliably find Qt5 libraries.
 
    if [ "$HAVE_QT5CORE" = "no" ] || [ "$HAVE_QT5GUI" = "no" ] || [ "$HAVE_QT5WIDGETS" = "no" ] || [ "$HAVE_QT5CONCURRENT" = "no" ] || [ "$HAVE_QT5NETWORK" = "no" ]; then
       die : 'Notice: Not building Qt support, required libraries were not found.'

qb/qb.comp.sh

@@ -2,6 +2,8 @@
 
 TEMP_C=.tmp.c
 TEMP_CXX=.tmp.cxx
+TEMP_MOC=.moc.h
+TEMP_CPP=.moc.cpp
 TEMP_EXE=.tmp
 
 # Checking for working C compiler
@@ -87,26 +89,6 @@ if [ "$OS" = "Win32" ]; then
 	echo "$echobuf ... $WINDRES"
 fi
 
-if [ "$HAVE_QT" != "no" ]; then
-	echobuf="Checking for moc"
-	if [ -z "$MOC" ]; then
-		MOC_PATH="none"
-		for moc in moc-qt5 moc; do
-			MOC="$(exists "$moc")" || MOC=""
-			[ "${MOC}" ] && {
-				MOC_PATH="$MOC"
-				break
-			}
-		done
-	fi
-
-	echo "$echobuf ... $MOC_PATH"
-
-	if [ "$MOC_PATH" = "none" ]; then
-		die : 'Warning: moc not found, Qt companion support will be disabled.'
-	fi
-fi
-
 if [ -z "$PKG_CONF_PATH" ]; then
 	PKG_CONF_PATH="none"
 	for pkgconf in pkgconf pkg-config; do
@@ -123,3 +105,58 @@ echo "Checking for pkg-config ... $PKG_CONF_PATH"
 if [ "$PKG_CONF_PATH" = "none" ]; then
 	die : 'Warning: pkg-config not found, package checks will fail.'
 fi
+
+# Checking for working moc
+cat << EOF > "$TEMP_MOC"
+#include <QTimeZone>
+class Test : public QObject
+{
+public:
+   Q_OBJECT
+   QTimeZone tz;
+};
+EOF
+
+HAVE_MOC=no
+if [ "$HAVE_QT" != "no" ] && [ "$HAVE_CXX" != "no" ] && [ "$PKG_CONF_PATH" != "none" ]; then
+	moc_works=0
+	if "$PKGCONF" --exists Qt5Core; then
+		if [ "$MOC" ]; then
+			"$MOC" -o "$TEMP_CPP" "$TEMP_MOC" >/dev/null 2>&1 &&
+			"$CXX" -o "$TEMP_EXE" $("$PKGCONF" --cflags --libs Qt5Core) -fPIC \
+				-c "$TEMP_CPP" >/dev/null 2>&1 &&
+			moc_works=1
+		else
+			for moc in moc-qt5 moc; do
+				MOC="$(exists "$moc")" || MOC=""
+				if [ "$MOC" ]; then
+					"$MOC" -o "$TEMP_CPP" "$TEMP_MOC" >/dev/null 2>&1 ||
+						continue
+					"$CXX" -o "$TEMP_EXE" $("$PKGCONF" --cflags --libs Qt5Core) \
+						-fPIC -c "$TEMP_CPP" >/dev/null 2>&1 && {
+						moc_works=1
+						break
+					}
+				fi
+			done
+		fi
+	else
+		MOC=""
+	fi
+
+	moc_status='does not work'
+	if [ "$moc_works" = '1' ]; then
+		moc_status='works'
+		HAVE_MOC='yes'
+	elif [ -z "$MOC" ]; then
+		moc_status='not found'
+	fi
+
+	echo "Checking for moc ... $MOC $moc_status"
+
+	if [ "$HAVE_MOC" != 'yes' ]; then
+		die : 'Warning: moc not found, Qt companion support will be disabled.'
+	fi
+fi
+
+rm -f -- "$TEMP_CPP" "$TEMP_EXE" "$TEMP_MOC"