detect cycles in rule dependencies

This fixes a stack overflow that occurred when having cycles in rule
dependencies.

Task-number: QBS-396

Change-Id: I1907ef66d74340c090b09be72d2352892baca986
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>

4 files changed, 56 insertions, 0 deletions

diff --git a/tests/auto/blackbox/testdata/ruleCycle/happy.grass b/tests/auto/blackbox/testdata/ruleCycle/happy.grass
new file mode 100644
index 000000000..8cf7f02e3
--- /dev/null
+++ b/tests/auto/blackbox/testdata/ruleCycle/happy.grass
@@ -0,0 +1 @@
+happy! happy! joy! joy!
diff --git a/tests/auto/blackbox/testdata/ruleCycle/ruleCycle.qbs b/tests/auto/blackbox/testdata/ruleCycle/ruleCycle.qbs
new file mode 100644
index 000000000..34d052e0a
--- /dev/null
+++ b/tests/auto/blackbox/testdata/ruleCycle/ruleCycle.qbs
@@ -0,0 +1,45 @@
+import qbs 1.0
+
+Project {
+    Product {
+        name: "the cycle of life"
+        type: "cow"
+        Group {
+            files: ["happy.grass"]
+            fileTags: ["grass"]
+        }
+        Rule {
+            inputs: ["grass"]
+            Artifact {
+                fileName: input.completeBaseName + ".cow"
+                fileTags: ["cow"]
+            }
+            prepare: { print("The cow feeds on grass."); }
+        }
+        Rule {
+            inputs: ["cow"]
+            Artifact {
+                fileName: input.completeBaseName + ".cow_pat"
+                fileTags: ["cow_pat"]
+            }
+            prepare: { print("The cow pat falls out of the cow."); }
+        }
+        Rule {
+            inputs: ["cow_pat"]
+            Artifact {
+                fileName: input.completeBaseName + ".fertilizer"
+                fileTags: ["fertilizer"]
+            }
+            prepare: { print("The cow pat is used as fertilizer."); }
+        }
+        Rule {
+            inputs: ["fertilizer"]
+            Artifact {
+                fileName: input.completeBaseName + ".grass"
+                fileTags: ["grass"]
+            }
+            prepare: { print("The fertilizer lets the grass grow."); }
+        }
+    }
+}
+
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index 84a5ad696..a78b68711 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -927,6 +927,15 @@ void TestBlackbox::ruleConditions()
     QVERIFY(!QFileInfo(buildDir + "/unzorted.foo.narf.zort").exists());
 }
 
+void TestBlackbox::ruleCycle()
+{
+    QDir::setCurrent(testDataDir + "/ruleCycle");
+    QbsRunParameters params;
+    params.expectFailure = true;
+    QVERIFY(runQbs(params) != 0);
+    QVERIFY(m_qbsStderr.contains("Cycle detected in rule dependencies"));
+}
+
 void TestBlackbox::trackAddQObjectHeader()
 {
     QDir::setCurrent(testDataDir + "/missingqobjectheader");
diff --git a/tests/auto/blackbox/tst_blackbox.h b/tests/auto/blackbox/tst_blackbox.h
index 124ed204f..6d4770d34 100644
--- a/tests/auto/blackbox/tst_blackbox.h
+++ b/tests/auto/blackbox/tst_blackbox.h
@@ -129,6 +129,7 @@ private slots:
     void recursiveRenaming();
     void recursiveWildcards();
     void ruleConditions();
+    void ruleCycle();
     void trackAddQObjectHeader();
     void trackRemoveQObjectHeader();
     void overrideProjectProperties();