qmake: Add support for running lrelease

CONFIG+=lrelease enables that all .ts files in
TRANSLATIONS or EXTRA_TRANSLATIONS are compiled by
lrelease.

EXTRA_TRANSLATIONS is a new variable that is only
processed by lrelease, but not lupdate - this
is useful for translation files that are supposed to
be empty, because they match the language of the
original translation sources.

If embed_translations is also set, the generated .qm
files will be made available through the Qt resource
system under :/i18n/. Alternatively, the user can
specify an installation target by setting
QM_FILES_INSTALL_PATH.

Note that relative paths in TRANSLATIONS are not taken
into account. That is,

  TRANSLATIONS = component1/de.ts component2/de.ts

will cause a conflict.

[ChangeLog][qmake] New CONFIG options lrelease and
embed_translations were added. CONFIG+=lrelease does
run lrelease on translation files listed in TRANSLATIONS
and EXTRA_TRANSLATIONS. CONFIG+=embed_translations does
include the generated .qm files as resources under
:/i18n/.

Change-Id: I94db5b8431d07b24f59b2c332ede91450f9c0c58
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

3 files changed, 44 insertions, 2 deletions

diff --git a/mkspecs/features/exclusive_builds.prf b/mkspecs/features/exclusive_builds.prf
index 2d7f0e1ab6..1ff9a04d42 100644
--- a/mkspecs/features/exclusive_builds.prf
+++ b/mkspecs/features/exclusive_builds.prf
@@ -38,5 +38,5 @@ defineTest(addExclusiveBuilds) {
 }
 
 # Default directories to process
-QMAKE_DIR_REPLACE = OBJECTS_DIR MOC_DIR RCC_DIR PRECOMPILED_DIR QGLTF_DIR DESTDIR TRACEGEN_DIR QMLCACHE_DIR
-QMAKE_DIR_REPLACE_SANE += QGLTF_DIR TRACEGEN_DIR QMLCACHE_DIR
+QMAKE_DIR_REPLACE = OBJECTS_DIR MOC_DIR RCC_DIR PRECOMPILED_DIR QGLTF_DIR DESTDIR TRACEGEN_DIR QMLCACHE_DIR LRELEASE_DIR
+QMAKE_DIR_REPLACE_SANE += QGLTF_DIR TRACEGEN_DIR QMLCACHE_DIR LRELEASE_DIR
diff --git a/mkspecs/features/lrelease.prf b/mkspecs/features/lrelease.prf
new file mode 100644
index 0000000000..1e828b64df
--- /dev/null
+++ b/mkspecs/features/lrelease.prf
@@ -0,0 +1,41 @@
+# Automatically generate .qm files out of .ts files in TRANSLATIONS and
+# EXTRA_TRANSLATIONS.
+#
+# If embed_translations is enabled, the generated .qm files are made available
+# in the resource system under :/i18n/.
+#
+# Otherwise, the .qm files are available in the build directory in LRELEASE_DIR.
+# They can also be automatically installed by setting QM_FILES_INSTALL_PATH.
+
+qtPrepareTool(QMAKE_LRELEASE, lrelease)
+
+isEmpty(LRELEASE_DIR): LRELEASE_DIR = .qm
+isEmpty(QM_FILES_RESOURCE_PREFIX): QM_FILES_RESOURCE_PREFIX = i18n
+
+lrelease.name = lrelease
+lrelease.input = TRANSLATIONS EXTRA_TRANSLATIONS
+lrelease.output = $$LRELEASE_DIR/${QMAKE_FILE_IN_BASE}.qm
+lrelease.commands = $$QMAKE_LRELEASE ${QMAKE_FILE_IN} $$QMAKE_LRELEASE_FLAGS -qm ${QMAKE_FILE_OUT}
+silent: lrelease.commands = @echo lrelease ${QMAKE_FILE_IN} && $$lrelease.commands
+lrelease.CONFIG = no_link
+QMAKE_EXTRA_COMPILERS += lrelease
+
+all_translations = $$TRANSLATIONS $$EXTRA_TRANSLATIONS
+for (translation, all_translations) {
+    # mirrors $$LRELEASE_DIR/${QMAKE_FILE_IN_BASE}.qm above
+    translation = $$basename(translation)
+    QM_FILES += $$OUT_PWD/$$LRELEASE_DIR/$$replace(translation, \\..*$, .qm)
+}
+embed_translations {
+    qmake_qm_files.files = $$QM_FILES
+    qmake_qm_files.base = $$OUT_PWD/$$LRELEASE_DIR
+    qmake_qm_files.prefix = $$QM_FILES_RESOURCE_PREFIX
+    RESOURCES += qmake_qm_files
+} else {
+    !isEmpty(QM_FILES_INSTALL_PATH) {
+        qm_files.files = $$QM_FILES
+        qm_files.path = $$QM_FILES_INSTALL_PATH
+        INSTALLS += qm_files
+    }
+    lrelease.CONFIG += target_predeps no_clean
+}
diff --git a/mkspecs/features/qt_build_config.prf b/mkspecs/features/qt_build_config.prf
index 021036e4f9..0c6c10dded 100644
--- a/mkspecs/features/qt_build_config.prf
+++ b/mkspecs/features/qt_build_config.prf
@@ -27,6 +27,7 @@ RCC_DIR = .rcc
 UI_DIR = .uic
 TRACEGEN_DIR = .tracegen
 QMLCACHE_DIR = .qmlcache
+LRELEASE_DIR = .qm
 intel_icl {
     # ICL 14.0 has a bug that makes it not find #includes in dirs starting with .
     MOC_DIR = tmp/moc