Introduce Rule.requiresInputs

This supports the use case of a rule that wants to create its output
even if no artifacts match the declared inputs. We have encountered it
several times in practice.

[ChangeLog] Introduced new property Rule.requiresInputs

Change-Id: If42ab347fb8e47b9117ac48fe3ce1b228566e0d8
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

6 files changed, 62 insertions, 0 deletions

diff --git a/tests/auto/blackbox/testdata/rule-with-non-required-inputs/a.inp b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/a.inp
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/a.inp
diff --git a/tests/auto/blackbox/testdata/rule-with-non-required-inputs/b.inp b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/b.inp
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/b.inp
diff --git a/tests/auto/blackbox/testdata/rule-with-non-required-inputs/c.inp b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/c.inp
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/c.inp
diff --git a/tests/auto/blackbox/testdata/rule-with-non-required-inputs/rule-with-non-required-inputs.qbs b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/rule-with-non-required-inputs.qbs
new file mode 100644
index 000000000..6719bc69d
--- /dev/null
+++ b/tests/auto/blackbox/testdata/rule-with-non-required-inputs/rule-with-non-required-inputs.qbs
@@ -0,0 +1,42 @@
+import qbs
+import qbs.TextFile
+
+Product {
+    name: "p"
+    type: ["p.out"]
+
+    property bool enableTagger
+
+    FileTagger {
+        condition: enableTagger
+        patterns: ["*.inp"]
+        fileTags: ["p.in"]
+    }
+
+    Rule {
+        multiplex: true
+        requiresInputs: false
+        inputs: ["p.in"]
+        Artifact {
+            filePath: "output.txt"
+            fileTags: ["p.out"]
+        }
+        prepare: {
+            var cmd = new JavaScriptCommand();
+            cmd.description = "Generating " + output.fileName;
+            cmd.sourceCode = function() {
+                var f = new TextFile(output.filePath, TextFile.WriteOnly);
+                f.write('(');
+                var inputsList = inputs["p.in"];
+                if (inputsList) {
+                    for (var i = 0; i < inputsList.length; ++i)
+                        f.write(inputsList[i].fileName + ',');
+                }
+                f.write(')');
+            };
+            return [cmd];
+        }
+    }
+
+    files: ["a.inp", "b.inp", "c.inp"]
+}
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index 0bdb9c81f..a7371c8a6 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -1598,6 +1598,25 @@ void TestBlackbox::ruleWithNoInputs()
     QVERIFY2(m_qbsStdout.contains("creating output"), m_qbsStdout.constData());
 }
 
+void TestBlackbox::ruleWithNonRequiredInputs()
+{
+    QDir::setCurrent(testDataDir + "/rule-with-non-required-inputs");
+    QbsRunParameters params("build", {"products.p.enableTagger:false"});
+    QCOMPARE(runQbs(params), 0);
+    QFile outFile(relativeProductBuildDir("p") + "/output.txt");
+    QVERIFY2(outFile.open(QIODevice::ReadOnly), qPrintable(outFile.errorString()));
+    QByteArray output = outFile.readAll();
+    QCOMPARE(output, QByteArray("()"));
+    outFile.close();
+    params.command = "resolve";
+    params.arguments = QStringList({"products.p.enableTagger:true"});
+    QCOMPARE(runQbs(params), 0);
+    QCOMPARE(runQbs(), 0);
+    QVERIFY2(outFile.open(QIODevice::ReadOnly), qPrintable(outFile.errorString()));
+    output = outFile.readAll();
+    QCOMPARE(output, QByteArray("(a.inp,b.inp,c.inp,)"));
+}
+
 void TestBlackbox::smartRelinking()
 {
     QDir::setCurrent(testDataDir + "/smart-relinking");
diff --git a/tests/auto/blackbox/tst_blackbox.h b/tests/auto/blackbox/tst_blackbox.h
index 83d8420e4..77f5762fb 100644
--- a/tests/auto/blackbox/tst_blackbox.h
+++ b/tests/auto/blackbox/tst_blackbox.h
@@ -156,6 +156,7 @@ private slots:
     void ruleConditions();
     void ruleCycle();
     void ruleWithNoInputs();
+    void ruleWithNonRequiredInputs();
     void smartRelinking();
     void smartRelinking_data();
     void soVersion();