Fix the qmlcachegen functionality

The qmlcache module was broken in an impressive number of ways:
    - We forgot to adapt the Probe to a5cc49f2c6.
    - The return value of the validate property is never evaluated;
      you have to throw an error for it to have an effect.
    - From 5.11 on, qmlcachegen does not support the
      --target-architecture option anymore.

Task-number: QBS-1353
Change-Id: I770ddc18ad2519c1d5db83bee9634717b1768d67
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

3 files changed, 37 insertions, 5 deletions

diff --git a/src/lib/qtprofilesetup/templates/qmlcache.qbs b/src/lib/qtprofilesetup/templates/qmlcache.qbs
index 246486c53..9111eb500 100644
--- a/src/lib/qtprofilesetup/templates/qmlcache.qbs
+++ b/src/lib/qtprofilesetup/templates/qmlcache.qbs
@@ -1,14 +1,22 @@
+import qbs.File
 import qbs.FileInfo
 import qbs.Process
+import qbs.Utilities
 
 Module {
     additionalProductTypes: ["qt.qml.qmlc", "qt.qml.jsc"]
-    validate: qmlcachegenProbe.found
+    validate: {
+        if (!qmlcachegenProbe.found)
+            throw "qmlcachegen unsupported for this target";
+    }
     property string qmlCacheGenPath: FileInfo.joinPaths(Qt.core.binPath, "qmlcachegen")
                                      + (qbs.hostOS.contains("windows") ? ".exe" : "")
+    property bool supportsAllArchitectures: Utilities.versionCompare(Qt.core.version, "5.11") >= 0
     property string installDir
 
     readonly property stringList _targetArgs: {
+        if (supportsAllArchitectures)
+            return [];
         function translateArch(arch) {
             if (arch === "x86")
                 return "i386";
@@ -24,15 +32,25 @@ Module {
     Depends { name: "Qt.core" }
     Probe {
         id: qmlcachegenProbe
+
+        property string arch: qbs.architecture
+        property string _qmlCacheGenPath: qmlCacheGenPath
+        property stringList targetArgs: _targetArgs
+        property bool _supportsAllArchitectures: supportsAllArchitectures
+
         configure: {
+            if (_supportsAllArchitectures) {
+                found = File.exists(_qmlCacheGenPath);
+                return;
+            }
             var process = new Process();
             found = false;
             try {
-                found = process.exec(qmlCacheGenPath,
-                                     _targetArgs.concat("--check-if-supported")) == 0;
+                found = process.exec(_qmlCacheGenPath,
+                                     targetArgs.concat("--check-if-supported")) == 0;
                 if (!found) {
                     var msg = "QML cache generation was requested but is unsupported on "
-                               + "architecture '" + qbs.architecture + "'.";
+                               + "architecture '" + arch + "'.";
                     console.warn(msg);
                 }
             } finally {
diff --git a/tests/auto/blackbox/testdata-qt/cached-qml/cached-qml.qbs b/tests/auto/blackbox/testdata-qt/cached-qml/cached-qml.qbs
index 398d3f4a9..5117557e1 100644
--- a/tests/auto/blackbox/testdata-qt/cached-qml/cached-qml.qbs
+++ b/tests/auto/blackbox/testdata-qt/cached-qml/cached-qml.qbs
@@ -1,4 +1,5 @@
 import qbs
+import qbs.Utilities
 
 CppApplication {
     name: "app"
@@ -27,4 +28,13 @@ CppApplication {
         qbs.install: true
         qbs.installDir: "data"
     }
+
+    Probe {
+        id: qtVersionProbe
+        property string qtVersion: Qt.core.version
+        configure: {
+            console.info("qmlcachegen must work: "
+                         + (Utilities.versionCompare(qtVersion, "5.11") >= 0))
+        }
+    }
 }
diff --git a/tests/auto/blackbox/tst_blackboxqt.cpp b/tests/auto/blackbox/tst_blackboxqt.cpp
index 93eb68f80..03e52590b 100644
--- a/tests/auto/blackbox/tst_blackboxqt.cpp
+++ b/tests/auto/blackbox/tst_blackboxqt.cpp
@@ -77,7 +77,11 @@ void TestBlackboxQt::cachedQml()
     QDir::setCurrent(testDataDir + "/cached-qml");
     QCOMPARE(runQbs(), 0);
     QString dataDir = relativeBuildDir() + "/install-root/data";
-    if (QFile::exists(dataDir + "/main.cpp")) {
+    QVERIFY2(m_qbsStdout.contains("qmlcachegen must work: true")
+             || m_qbsStdout.contains("qmlcachegen must work: false"),
+             m_qbsStdout.constData());
+    if (m_qbsStdout.contains("qmlcachegen must work: false")
+            && QFile::exists(dataDir + "/main.cpp")) {
         // If C++ source files were installed then Qt.qmlcache is not available. See project file.
         QSKIP("No QML cache files generated.");
     }