Doc: Document TR_EXCLUDE

Pick-to: 6.5 6.6
Change-Id: Ib2e06e46f44564a2c7581ff4d7f3d8a29d2756c9
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Kai Köhne <kai.koehne@qt.io>

qmake/doc/snippets/code/doc_src_qmake-manual.pro

@@ -961,3 +961,25 @@ translations_de.files = $$PWD/de.lproj/InfoPlist.strings
 
 QMAKE_BUNDLE_DATA += translations_en translations_de
 #! [189]
+
+#! [TR_EXCLUDE sources]
+SOURCES += main.cpp \
+    excluded.cpp \
+    3rdparty/sqlite3.h \
+    3rdparty/sqlite3.c
+TR_EXCLUDE += excluded.cpp 3rdparty/*
+#! [TR_EXCLUDE sources]
+
+#! [TR_EXCLUDE SUBDIRS]
+SUBDIRS += \
+    libs \
+    apps \
+    tests
+TR_EXCLUDE += tests
+#! [TR_EXCLUDE SUBDIRS]
+
+#! [TR_EXCLUDE include paths]
+linux {
+    TR_EXCLUDE += /usr/include/boost/*
+}
+#! [TR_EXCLUDE include paths]

qmake/doc/src/qmake-manual.qdoc

@@ -3146,6 +3146,25 @@
     See the \l{Qt Linguist Manual} for more information about
     internationalization (i18n) and localization (l10n) with Qt.
 
+    \section1 TR_EXCLUDE
+
+    Specifies a list of paths (source files, subdirectories, and C++ include
+    paths) to be excluded from handling in \c{lupdate}. The paths may contain
+    wildcards. Relative paths are considered to be relative to
+    \l{_PRO_FILE_PWD_}.
+
+    For example, to exclude source files:
+
+    \snippet code/doc_src_qmake-manual.pro TR_EXCLUDE sources
+
+    To exclude subdirectories of a \c SUBDIRS project:
+
+    \snippet code/doc_src_qmake-manual.pro TR_EXCLUDE SUBDIRS
+
+    To speed up lupdate's C++ parser, exclude include paths:
+
+    \snippet code/doc_src_qmake-manual.pro TR_EXCLUDE include paths
+
     \section1 UI_DIR
 
     Specifies the directory where all intermediate files from uic