Speed up clang-tidy when profiling in on.

sbenzaquen · sbenzaquen · commit 7af88000955b · 2014-10-27T15:22:59.000Z
Summary: Speed up clang-tidy when profiling in on. It makes profiling runs twice as fast by reusing the time samples between the different actions. It also joins together the sampling of different matchers of the same check. Reviewers: alexfh Subscribers: klimek, cfe-commits Differential Revision: http://reviews.llvm.org/D5972 llvm-svn: 220682
diff --git a/clang/lib/ASTMatchers/ASTMatchFinder.cpp b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
@@ -307,18 +307,20 @@ class MatchASTVisitor : public RecursiveASTVisitor<MatchASTVisitor>,
 
   void onStartOfTranslationUnit() {
     const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
+    TimeBucketRegion Timer;
     for (MatchCallback *MC : Matchers->AllCallbacks) {
-      TimeRegion Timer(EnableCheckProfiling ? &TimeByBucket[MC->getID()]
-                                            : nullptr);
+      if (EnableCheckProfiling)
+        Timer.setBucket(&TimeByBucket[MC->getID()]);
       MC->onStartOfTranslationUnit();
     }
   }
 
   void onEndOfTranslationUnit() {
     const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
+    TimeBucketRegion Timer;
     for (MatchCallback *MC : Matchers->AllCallbacks) {
-      TimeRegion Timer(EnableCheckProfiling ? &TimeByBucket[MC->getID()]
-                                            : nullptr);
+      if (EnableCheckProfiling)
+        Timer.setBucket(&TimeByBucket[MC->getID()]);
       MC->onEndOfTranslationUnit();
     }
   }
@@ -489,19 +491,32 @@ class MatchASTVisitor : public RecursiveASTVisitor<MatchASTVisitor>,
   bool shouldUseDataRecursionFor(clang::Stmt *S) const { return false; }
 
 private:
-  class TimeRegion {
+  class TimeBucketRegion {
   public:
-    TimeRegion(llvm::TimeRecord *Record) : Record(Record) {
-      if (Record)
-        *Record -= llvm::TimeRecord::getCurrentTime(true);
-    }
-    ~TimeRegion() {
-      if (Record)
-        *Record += llvm::TimeRecord::getCurrentTime(false);
+    TimeBucketRegion() : Bucket(nullptr) {}
+    ~TimeBucketRegion() { setBucket(nullptr); }
+
+    /// \brief Start timing for \p NewBucket.
+    ///
+    /// If there was a bucket already set, it will finish the timing for that
+    /// other bucket.
+    /// \p NewBucket will be timed until the next call to \c setBucket() or
+    /// until the \c TimeBucketRegion is destroyed.
+    /// If \p NewBucket is the same as the currently timed bucket, this call
+    /// does nothing.
+    void setBucket(llvm::TimeRecord *NewBucket) {
+      if (Bucket != NewBucket) {
+        auto Now = llvm::TimeRecord::getCurrentTime(true);
+        if (Bucket)
+          *Bucket += Now;
+        if (NewBucket)
+          *NewBucket -= Now;
+        Bucket = NewBucket;
+      }
     }
 
   private:
-    llvm::TimeRecord *Record;
+    llvm::TimeRecord *Bucket;
   };
 
   /// \brief Runs all the \p Matchers on \p Node.
@@ -510,9 +525,10 @@ class MatchASTVisitor : public RecursiveASTVisitor<MatchASTVisitor>,
   template <typename T, typename MC>
   void matchImpl(const T &Node, const MC &Matchers) {
     const bool EnableCheckProfiling = Options.CheckProfiling.hasValue();
+    TimeBucketRegion Timer;
     for (const auto &MP : Matchers) {
-      TimeRegion Timer(EnableCheckProfiling ? &TimeByBucket[MP.second->getID()]
-                                            : nullptr);
+      if (EnableCheckProfiling)
+        Timer.setBucket(&TimeByBucket[MP.second->getID()]);
       BoundNodesTreeBuilder Builder;
       if (MP.first.matches(Node, this, &Builder)) {
         MatchVisitor Visitor(ActiveASTContext, MP.second);
