Fix skipping of qml cache generation on unsupported architectures

Detect support for the target architecture at qmake time and gently
skip the process.

Change-Id: I7cc22a0cfb9a8b503c182062a56e506035f84fa2
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 35 insertions, 7 deletions

diff --git a/tools/qmlcachegen/qmlcache.prf b/tools/qmlcachegen/qmlcache.prf
index e0c62ec4d3..5cac5592c3 100644
--- a/tools/qmlcachegen/qmlcache.prf
+++ b/tools/qmlcachegen/qmlcache.prf
@@ -1,10 +1,22 @@
-qtPrepareTool(QML_CACHEGEN, qmlcachegen)
+static {
+    message("QML cache generation ahead of time is not supported in static builds")
+    return()
+}
+
+qtPrepareTool(QML_CACHEGEN, qmlcachegen, _ARCH_CHECK)
 
 isEmpty(TARGETPATH): error("Must set TARGETPATH (QML import name) for ahead-of-time QML cache generation")
 
 !isEmpty(QT_TARGET_ARCH):QML_CACHEGEN_ARCH=$$QT_TARGET_ARCH
 else:QML_CACHEGEN_ARCH=$$QT_ARCH
 
+QML_CACHEGEN_ARGS=--target-architecture=$$QML_CACHEGEN_ARCH
+
+!system($$QML_CACHEGEN_ARCH_CHECK $$QML_CACHEGEN_ARGS --check-if-supported) {
+    message("QML cache generation requested but target architecture $$QML_CACHEGEN_ARCH is not supported.")
+    return()
+}
+
 CACHEGEN_FILES=
 for(qmlf, QML_FILES) {
     contains(qmlf,.*\\.js$)|contains(qmlf,.*\\.qml$) {
@@ -19,7 +31,7 @@ prefix_build {
     qmlcachegen.output = $$[QT_INSTALL_QML]/$$TARGETPATH/${QMAKE_FILE_IN}c
     qmlcachegen.CONFIG = no_link target_predeps
 }
-qmlcachegen.commands = $$QML_CACHEGEN --target-architecture=$$QML_CACHEGEN_ARCH -o ${QMAKE_FILE_OUT} ${QMAKE_FILE_IN}
+qmlcachegen.commands = $$QML_CACHEGEN $$QML_CACHEGEN_ARGS -o ${QMAKE_FILE_OUT} ${QMAKE_FILE_IN}
 qmlcachegen.name = Generate QML Cache ${QMAKE_FILE_IN}
 qmlcachegen.variable_out = GENERATED_FILES
 
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
index c0faabe393..fa75d14c8e 100644
--- a/tools/qmlcachegen/qmlcachegen.cpp
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -274,25 +274,41 @@ int main(int argc, char **argv)
     QCommandLineOption outputFileOption(QStringLiteral("o"), QCoreApplication::translate("main", "Output file name"), QCoreApplication::translate("main", "file name"));
     parser.addOption(outputFileOption);
 
+    QCommandLineOption checkIfSupportedOption(QStringLiteral("check-if-supported"), QCoreApplication::translate("main", "Check if cache generate is supported on the specified target architecture"));
+    parser.addOption(checkIfSupportedOption);
+
     parser.addPositionalArgument(QStringLiteral("[qml file]"),
             QStringLiteral("QML source file to generate cache for."));
 
     parser.process(app);
 
-    const QStringList sources = parser.positionalArguments();
-    if (sources.isEmpty()){
+    if (!parser.isSet(targetArchitectureOption)) {
+        fprintf(stderr, "Target architecture not specified. Please specify with --target-architecture=<arch>\n");
         parser.showHelp();
-    } else if (sources.count() > 1) {
-        fprintf(stderr, "%s\n", qPrintable(QStringLiteral("Too many input files specified: '") + sources.join(QStringLiteral("' '")) + QLatin1Char('\'')));
         return EXIT_FAILURE;
     }
-    const QString inputFile = sources.first();
 
     QScopedPointer<QV4::EvalISelFactory> isel;
     const QString targetArchitecture = parser.value(targetArchitectureOption);
 
     isel.reset(QV4::JIT::createISelForArchitecture(targetArchitecture));
 
+    if (parser.isSet(checkIfSupportedOption)) {
+        if (isel.isNull())
+            return EXIT_FAILURE;
+        else
+            return EXIT_SUCCESS;
+    }
+
+    const QStringList sources = parser.positionalArguments();
+    if (sources.isEmpty()){
+        parser.showHelp();
+    } else if (sources.count() > 1) {
+        fprintf(stderr, "%s\n", qPrintable(QStringLiteral("Too many input files specified: '") + sources.join(QStringLiteral("' '")) + QLatin1Char('\'')));
+        return EXIT_FAILURE;
+    }
+    const QString inputFile = sources.first();
+
     if (!isel)
         isel.reset(new QV4::Moth::ISelFactory);