provide "compile single file" functionality

To compile just one single file without any further effects,
pass the file name to BuildOptions::setChangedFiles, and the
file tags of the desired results to BuildOptions::setActiveFileTags.

Task-number: QBS-283
Change-Id: I70213b248e1e07fd7524a54f7f2e4f250621967f
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>

4 files changed, 35 insertions, 0 deletions

diff --git a/src/lib/buildgraph/executor.cpp b/src/lib/buildgraph/executor.cpp
index b41c5dd93..596672ebc 100644
--- a/src/lib/buildgraph/executor.cpp
+++ b/src/lib/buildgraph/executor.cpp
@@ -182,6 +182,7 @@ void Executor::doBuild()
     m_leaves.clear();
     m_error.clear();
     m_explicitlyCanceled = false;
+    m_activeFileTags = FileTags::fromStringList(m_buildOptions.activeFileTags());
 
     setState(ExecutorRunning);
 
@@ -416,6 +417,14 @@ void Executor::buildArtifact(Artifact *artifact)
         }
     }
 
+    // Skip if we're building just one file and the file tags do not match.
+    if (!m_activeFileTags.isEmpty() && !m_activeFileTags.matches(artifact->fileTags)) {
+        if (m_doDebug)
+            m_logger.qbsDebug() << "[EXEC] file tags do not match. Skipping.";
+        finishArtifact(artifact);
+        return;
+    }
+
     // Skip transformers that do not need to be built.
     if (!mustExecuteTransformer(artifact->transformer)) {
         if (m_doDebug)
diff --git a/src/lib/buildgraph/executor.h b/src/lib/buildgraph/executor.h
index e55909744..1a3b44702 100644
--- a/src/lib/buildgraph/executor.h
+++ b/src/lib/buildgraph/executor.h
@@ -129,6 +129,7 @@ private:
     int m_mocEffort;
     ErrorInfo m_error;
     bool m_explicitlyCanceled;
+    FileTags m_activeFileTags;
     const bool m_doTrace;
     const bool m_doDebug;
 };
diff --git a/src/lib/tools/buildoptions.cpp b/src/lib/tools/buildoptions.cpp
index 945302e83..e836206fb 100644
--- a/src/lib/tools/buildoptions.cpp
+++ b/src/lib/tools/buildoptions.cpp
@@ -42,6 +42,7 @@ public:
     }
 
     QStringList changedFiles;
+    QStringList activeFileTags;
     int maxJobCount;
     bool dryRun;
     bool keepGoing;
@@ -96,6 +97,27 @@ void BuildOptions::setChangedFiles(const QStringList &changedFiles)
 }
 
 /*!
+ * \brief The list of active file tags.
+ * \sa setActiveFileTags
+ */
+QStringList BuildOptions::activeFileTags() const
+{
+    return d->activeFileTags;
+}
+
+/*!
+ * \brief Set the list of active file tags.
+ * If this list is non-empty, then every transformer with non-matching output file tags is skipped.
+ * E.g. set changed files to "foo.cpp" and activeFileTags to ["obj"] to run the compiler
+ * on foo.cpp without further processing like linking.
+ * \sa activeFileTags
+ */
+void BuildOptions::setActiveFileTags(const QStringList &fileTags)
+{
+    d->activeFileTags = fileTags;
+}
+
+/*!
  * \brief Returns the default value for \c maxJobCount.
  * This value will be used when \c maxJobCount has not been set explicitly.
  */
diff --git a/src/lib/tools/buildoptions.h b/src/lib/tools/buildoptions.h
index 0f40abb9e..7bf37c66e 100644
--- a/src/lib/tools/buildoptions.h
+++ b/src/lib/tools/buildoptions.h
@@ -48,6 +48,9 @@ public:
     QStringList changedFiles() const;
     void setChangedFiles(const QStringList &changedFiles);
 
+    QStringList activeFileTags() const;
+    void setActiveFileTags(const QStringList &fileTags);
+
     static int defaultMaxJobCount();
     int maxJobCount() const;
     void setMaxJobCount(int jobCount);