fix spurious caching error in InputArtifactScanner

Depending on which scanner was used first, the input artifact got
scanned with or without include paths. The result was cached and
potentially retrieved in the next round where it might be wrong.
Keep a dependency cache per scanner, because different scanners
might yield different results.

Change-Id: I0eb6ac9675205e26600ad99015a17e911ecb68a7
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>

2 files changed, 28 insertions, 18 deletions

diff --git a/src/lib/buildgraph/inputartifactscanner.cpp b/src/lib/buildgraph/inputartifactscanner.cpp
index 670dbd74f..bbe3f778a 100644
--- a/src/lib/buildgraph/inputartifactscanner.cpp
+++ b/src/lib/buildgraph/inputartifactscanner.cpp
@@ -165,27 +165,37 @@ void InputArtifactScanner::scan()
     for (; it != m_artifact->transformer->inputs.end(); ++it) {
         Artifact *inputArtifact = *it;
         QStringList includePaths;
-        bool includePathsCollected = false;
-
-        InputArtifactScannerContext::CacheItem &cacheItem = m_context->cache[inputArtifact->properties];
+        bool mustCollectIncludePaths = false;
 
+        QSet<ScannerPlugin *> scanners;
         foreach (const QString &fileTag, inputArtifact->fileTags) {
-            QList<ScannerPlugin *> scanners = ScannerPluginManager::scannersForFileTag(fileTag);
-            foreach (ScannerPlugin *scanner, scanners) {
-                if (scanner->usesCppIncludePaths && !includePathsCollected) {
-                    if (cacheItem.valid) {
-                        //qDebug() << "CACHE HIT";
-                        includePaths = cacheItem.includePaths;
-                    } else {
-                        //qDebug() << "CACHE MISS";
-                        includePaths = collectIncludePaths(inputArtifact->properties->value().value("modules").toMap());
-                        cacheItem.includePaths = includePaths;
-                        cacheItem.valid = true;
-                    }
-                }
-                scanForFileDependencies(scanner, includePaths, inputArtifact, cacheItem.resolvedDependenciesCache);
+            foreach (ScannerPlugin *scanner, ScannerPluginManager::scannersForFileTag(fileTag)) {
+                scanners += scanner;
+                if (scanner->usesCppIncludePaths)
+                    mustCollectIncludePaths = true;
+            }
+        }
+
+        InputArtifactScannerContext::CacheItem &cacheItem = m_context->cache[inputArtifact->properties];
+        if (mustCollectIncludePaths) {
+            if (cacheItem.valid) {
+                //qDebug() << "CACHE HIT";
+                includePaths = cacheItem.includePaths;
+            } else {
+                //qDebug() << "CACHE MISS";
+                includePaths = collectIncludePaths(inputArtifact->properties->value().value("modules").toMap());
+                cacheItem.includePaths = includePaths;
+                cacheItem.valid = true;
             }
         }
+
+        const QStringList emptyIncludePaths;
+        foreach (ScannerPlugin *scanner, scanners) {
+            scanForFileDependencies(scanner,
+                                    scanner->usesCppIncludePaths ? includePaths : emptyIncludePaths,
+                                    inputArtifact,
+                                    cacheItem.resolvedDependenciesCache[scanner]);
+        }
     }
 }
 
diff --git a/src/lib/buildgraph/inputartifactscanner.h b/src/lib/buildgraph/inputartifactscanner.h
index f6d0faefa..ddc132c41 100644
--- a/src/lib/buildgraph/inputartifactscanner.h
+++ b/src/lib/buildgraph/inputartifactscanner.h
@@ -85,7 +85,7 @@ private:
 
         bool valid;
         QStringList includePaths;
-        ResolvedDependenciesCache resolvedDependenciesCache;
+        QHash<ScannerPlugin *, ResolvedDependenciesCache> resolvedDependenciesCache;
     };
 
     QHash<PropertyMapConstPtr, CacheItem> cache;