Add FileTagger.priority

Enable users to override FileTagger items by creating a conflicting
FileTagger that has a higher numerical priority value.

[ChangeLog] Introduced the property FileTagger.priority, and enable
users to override FileTagger items.

Change-Id: Idc6f5d003b7ad468f03a2eae5d19404c1f3eb06b
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

9 files changed, 85 insertions, 8 deletions

diff --git a/doc/reference/items/language/filetagger.qdoc b/doc/reference/items/language/filetagger.qdoc
index 4a87824f2..55fbb4ac9 100644
--- a/doc/reference/items/language/filetagger.qdoc
+++ b/doc/reference/items/language/filetagger.qdoc
@@ -34,9 +34,21 @@
     \keyword QML.FileTagger
 
     \title FileTagger Item
-    \brief Maps file patterns to tags.
+    \brief Assigns file tags to files.
 
-    This item maps file patterns to tags. It can be attached to a product or a module.
+    This item assigns file tags to files.
+    The FileTagger item can appear in \c{Product} items or \c{Module} items.
+
+    For every source artifact that has no file tag, \QBS will search for a
+    FileTagger with a pattern that matches the file name of the source
+    artifact. If a matching file tagger is found, then the file tags specified
+    in the FileTagger item are assigned to the source artifact.
+
+    If there is more than one matching FileTagger, all file taggers with the
+    same highest priority are taken into account and their file tags are
+    accumulated.
+
+    The FileTagger item can be attached to a product or a module.
     In the latter case, its effect is the same as if it had been attached to all products having
     a dependency on the respective module. For instance, the cpp module of \QBS has, among others,
     the following file tagger:
@@ -71,17 +83,27 @@
         \li Property
         \li Type
         \li Default
+        \li Since
         \li Description
     \row
         \li patterns
         \li stringList
         \li none
+        \li 1.0
         \li The patterns to match against. Supports the usual wildcards '*', '?' and '[]'.
             Neither the list itself nor any of its elements may be empty.
     \row
         \li fileTags
         \li list
         \li empty list
+        \li 1.0
         \li Tags to attach to a product's files. These can then be matched by a rule.
+    \row
+        \li priority
+        \li int
+        \li 0
+        \li 1.10
+        \li The priority of the FileTagger. A higher numerical value means
+            higher priority.
     \endtable
 */
diff --git a/src/lib/corelib/language/builtindeclarations.cpp b/src/lib/corelib/language/builtindeclarations.cpp
index c8ad3c245..32a85665d 100644
--- a/src/lib/corelib/language/builtindeclarations.cpp
+++ b/src/lib/corelib/language/builtindeclarations.cpp
@@ -235,6 +235,7 @@ void BuiltinDeclarations::addFileTaggerItem()
     item << conditionProperty();
     item << PropertyDeclaration(QLatin1String("patterns"), PropertyDeclaration::StringList);
     item << PropertyDeclaration(QLatin1String("fileTags"), PropertyDeclaration::StringList);
+    item << PropertyDeclaration(QLatin1String("priority"), PropertyDeclaration::Integer);
     insert(item);
 }
 
diff --git a/src/lib/corelib/language/evaluator.cpp b/src/lib/corelib/language/evaluator.cpp
index c4b5419fb..193e73618 100644
--- a/src/lib/corelib/language/evaluator.cpp
+++ b/src/lib/corelib/language/evaluator.cpp
@@ -92,6 +92,15 @@ bool Evaluator::boolValue(const Item *item, const QString &name, bool defaultVal
     return v.toBool();
 }
 
+int Evaluator::intValue(const Item *item, const QString &name, int defaultValue,
+                        bool *propertyWasSet)
+{
+    QScriptValue v;
+    if (!evaluateProperty(&v, item, name, propertyWasSet))
+        return defaultValue;
+    return v.toInt32();
+}
+
 FileTags Evaluator::fileTagsValue(const Item *item, const QString &name, bool *propertySet)
 {
     return FileTags::fromStringList(stringListValue(item, name, propertySet));
diff --git a/src/lib/corelib/language/evaluator.h b/src/lib/corelib/language/evaluator.h
index 80ab9a3b4..840c808ed 100644
--- a/src/lib/corelib/language/evaluator.h
+++ b/src/lib/corelib/language/evaluator.h
@@ -69,6 +69,8 @@ public:
     QScriptValue value(const Item *item, const QString &name, bool *propertySet = 0);
     bool boolValue(const Item *item, const QString &name, bool defaultValue = false,
                    bool *propertyWasSet = 0);
+    int intValue(const Item *item, const QString &name, int defaultValue = 0,
+                 bool *propertyWasSet = 0);
     FileTags fileTagsValue(const Item *item, const QString &name, bool *propertySet = 0);
     QString stringValue(const Item *item, const QString &name,
                         const QString &defaultValue = QString(), bool *propertyWasSet = 0);
diff --git a/src/lib/corelib/language/language.cpp b/src/lib/corelib/language/language.cpp
index 4c66b4e16..988e7489e 100644
--- a/src/lib/corelib/language/language.cpp
+++ b/src/lib/corelib/language/language.cpp
@@ -69,6 +69,7 @@
 #include <QtScript/qscriptvalue.h>
 
 #include <algorithm>
+#include <memory>
 #include <mutex>
 
 namespace qbs {
@@ -84,8 +85,8 @@ template<typename T> bool equals(const T *v1, const T *v2)
 }
 
 
-FileTagger::FileTagger(const QStringList &patterns, const FileTags &fileTags)
-    : m_fileTags(fileTags)
+FileTagger::FileTagger(const QStringList &patterns, const FileTags &fileTags, int priority)
+    : m_fileTags(fileTags), m_priority(priority)
 {
     setPatterns(patterns);
 }
@@ -107,6 +108,7 @@ void FileTagger::load(PersistentPool &pool)
 {
     setPatterns(pool.load<QStringList>());
     pool.load(m_fileTags);
+    pool.load(m_priority);
 }
 
 void FileTagger::store(PersistentPool &pool) const
@@ -116,6 +118,7 @@ void FileTagger::store(PersistentPool &pool) const
         patterns << regExp.pattern();
     pool.store(patterns);
     pool.store(m_fileTags);
+    pool.store(m_priority);
 }
 
 
@@ -501,9 +504,19 @@ QList<SourceArtifactPtr> ResolvedProduct::allEnabledFiles() const
 FileTags ResolvedProduct::fileTagsForFileName(const QString &fileName) const
 {
     FileTags result;
+    std::unique_ptr<int> priority;
     for (const FileTaggerConstPtr &tagger : qAsConst(fileTaggers)) {
         for (const QRegExp &pattern : tagger->patterns()) {
             if (FileInfo::globMatches(pattern, fileName)) {
+                if (priority) {
+                    if (*priority != tagger->priority()) {
+                        // The taggers are expected to be sorted by priority.
+                        QBS_ASSERT(*priority > tagger->priority(), return result);
+                        return result;
+                    }
+                } else {
+                    priority.reset(new int(tagger->priority()));
+                }
                 result.unite(tagger->fileTags());
                 break;
             }
diff --git a/src/lib/corelib/language/language.h b/src/lib/corelib/language/language.h
index 4df1fd976..64d51a47f 100644
--- a/src/lib/corelib/language/language.h
+++ b/src/lib/corelib/language/language.h
@@ -78,15 +78,17 @@ class FileTagger : public PersistentObject
 {
 public:
     static FileTaggerPtr create() { return FileTaggerPtr(new FileTagger); }
-    static FileTaggerPtr create(const QStringList &patterns, const FileTags &fileTags) {
-        return FileTaggerPtr(new FileTagger(patterns, fileTags));
+    static FileTaggerPtr create(const QStringList &patterns, const FileTags &fileTags,
+                                int priority) {
+        return FileTaggerPtr(new FileTagger(patterns, fileTags, priority));
     }
 
     const QList<QRegExp> &patterns() const { return m_patterns; }
     const FileTags &fileTags() const { return m_fileTags; }
+    int priority() const { return m_priority; }
 
 private:
-    FileTagger(const QStringList &patterns, const FileTags &fileTags);
+    FileTagger(const QStringList &patterns, const FileTags &fileTags, int priority);
     FileTagger() {}
 
     void setPatterns(const QStringList &patterns);
@@ -96,6 +98,7 @@ private:
 
     QList<QRegExp> m_patterns;
     FileTags m_fileTags;
+    int m_priority = 0;
 };
 
 class Probe : public PersistentObject
diff --git a/src/lib/corelib/language/projectresolver.cpp b/src/lib/corelib/language/projectresolver.cpp
index 348b0af42..d1d70e445 100644
--- a/src/lib/corelib/language/projectresolver.cpp
+++ b/src/lib/corelib/language/projectresolver.cpp
@@ -943,7 +943,9 @@ void ProjectResolver::resolveFileTagger(Item *item, ProjectContext *projectConte
         if (pattern.isEmpty())
             throw ErrorInfo(Tr::tr("A FileTagger pattern must not be empty."), item->location());
     }
-    fileTaggers += FileTagger::create(patterns, fileTags);
+
+    const int priority = m_evaluator->intValue(item, QLatin1String("priority"));
+    fileTaggers += FileTagger::create(patterns, fileTags, priority);
 }
 
 void ProjectResolver::resolveScanner(Item *item, ProjectResolver::ProjectContext *projectContext)
@@ -1185,6 +1187,10 @@ void ProjectResolver::postProcess(const ResolvedProductPtr &product,
                                   ProjectContext *projectContext) const
 {
     product->fileTaggers += projectContext->fileTaggers;
+    std::sort(std::begin(product->fileTaggers), std::end(product->fileTaggers),
+              [] (const FileTaggerConstPtr &a, const FileTaggerConstPtr &b) {
+        return a->priority() > b->priority();
+    });
     for (const RulePtr &rule : qAsConst(projectContext->rules)) {
         RulePtr clonedRule = rule->clone();
         clonedRule->product = product.get();
diff --git a/tests/auto/language/testdata/filetags.qbs b/tests/auto/language/testdata/filetags.qbs
index eb1cf57c6..b2a85f953 100644
--- a/tests/auto/language/testdata/filetags.qbs
+++ b/tests/auto/language/testdata/filetags.qbs
@@ -58,4 +58,24 @@ Project {
             fileTags: ["zzz"]
         }
     }
+
+    Product {
+        name: "prioritized_filetagger"
+        files: ["main.cpp"]
+        FileTagger {
+            patterns: ["*.cpp"]
+            fileTags: ["cpp1"]
+            priority: 3
+        }
+        FileTagger {
+            patterns: ["*.cpp"]
+            fileTags: ["cpp2"]
+            priority: 3
+        }
+        FileTagger {
+            patterns: ["*.cpp"]
+            fileTags: ["ignored"]
+            priority: 2
+        }
+    }
 }
diff --git a/tests/auto/language/tst_language.cpp b/tests/auto/language/tst_language.cpp
index fc04f9e6a..78a8caf1a 100644
--- a/tests/auto/language/tst_language.cpp
+++ b/tests/auto/language/tst_language.cpp
@@ -2305,6 +2305,7 @@ void TestLanguage::fileTags_data()
     QTest::newRow("set_file_tag_via_group") << 2 << (QStringList() << "c++");
     QTest::newRow("override_file_tag_via_group") << 2 << (QStringList() << "c++");
     QTest::newRow("add_file_tag_via_group") << 2 << (QStringList() << "cpp" << "zzz");
+    QTest::newRow("prioritized_filetagger") << 1 << (QStringList() << "cpp1" << "cpp2");
     QTest::newRow("cleanup") << 0 << QStringList();
 }