Restore the QV4_WRITE_PERF_MAP feature

We want to be able to generate perf map files for JITed code.

Task-number: QTBUG-67056
Change-Id: I56899e1dbf184083d94efe926d21fca4f9ea1e18
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 68 insertions, 0 deletions

diff --git a/tests/auto/qml/qjsengine/tst_qjsengine.cpp b/tests/auto/qml/qjsengine/tst_qjsengine.cpp
index 8f3011001b..8ffaa96569 100644
--- a/tests/auto/qml/qjsengine/tst_qjsengine.cpp
+++ b/tests/auto/qml/qjsengine/tst_qjsengine.cpp
@@ -202,6 +202,7 @@ private slots:
     void malformedExpression();
 
     void scriptScopes();
+    void perfMapFile();
 
 signals:
     void testSignal();
@@ -4130,6 +4131,73 @@ void tst_QJSEngine::scriptScopes()
     QCOMPARE(use.toInt(), 42);
 }
 
+static const char *perfMapKey = "QV4_PROFILE_WRITE_PERF_MAP";
+static const char *jitCallKey = "QV4_JIT_CALL_THRESHOLD";
+
+struct EnvironmentModifier {
+    const bool hasPerfMap = false;
+    const bool hasJitCall = false;
+    const QByteArray perfMap;
+    const QByteArray jitCall;
+
+    EnvironmentModifier() :
+        hasPerfMap(qEnvironmentVariableIsSet(perfMapKey)),
+        hasJitCall(qEnvironmentVariableIsSet(jitCallKey)),
+        perfMap(qgetenv(perfMapKey)),
+        jitCall(qgetenv(jitCallKey))
+    {
+        qputenv(perfMapKey, "1");
+        qputenv(jitCallKey, "0");
+    }
+
+    ~EnvironmentModifier()
+    {
+        if (hasPerfMap)
+            qputenv(perfMapKey, perfMap);
+        else
+            qunsetenv(perfMapKey);
+
+        if (hasJitCall)
+            qputenv(jitCallKey, jitCall);
+        else
+            qunsetenv(jitCallKey);
+    }
+};
+
+void tst_QJSEngine::perfMapFile()
+{
+#if !defined(Q_OS_LINUX)
+    QSKIP("perf map files are only generated on linux");
+#else
+    EnvironmentModifier modifier;
+    Q_UNUSED(modifier);
+    QJSEngine engine;
+    QJSValue def = engine.evaluate("'use strict'; function foo() { return 42 }");
+    QVERIFY(!def.isError());
+    QJSValue use = engine.evaluate("'use strict'; foo()");
+    QVERIFY(use.isNumber());
+    QFile file(QString::fromLatin1("/tmp/perf-%1.map").arg(QCoreApplication::applicationPid()));
+    QVERIFY(file.exists());
+    QVERIFY(file.open(QIODevice::ReadOnly));
+    QList<QByteArray> functions;
+    while (!file.atEnd()) {
+        const QByteArray contents = file.readLine();
+        QVERIFY(contents.endsWith('\n'));
+        QList<QByteArray> fields = contents.split(' ');
+        QCOMPARE(fields.length(), 3);
+        bool ok = false;
+        const qulonglong address = fields[0].toULongLong(&ok, 16);
+        QVERIFY(ok);
+        QVERIFY(address > 0);
+        const ulong size = fields[1].toULong(&ok, 16);
+        QVERIFY(ok);
+        QVERIFY(size > 0);
+        functions.append(fields[2]);
+    }
+    QVERIFY(functions.contains("foo\n"));
+#endif
+}
+
 QTEST_MAIN(tst_QJSEngine)
 
 #include "tst_qjsengine.moc"