[analyzer] Solve another source of non-determinism in the diagnostic

engine.

The code that was supposed to split the tie in a deterministic way is
not deterministic. Most likely one of the profile methods uses a
pointer. After this change we do finally get the consistent diagnostic
output. Testing this requires running the analyzer on large code bases
and diffing the results.

llvm-svn: 161224

2 files changed, 7 insertions, 14 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
index 1eaf1f9f762..7ba2fa7fdd0 100644
--- a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -1536,6 +1536,8 @@ void BugReporter::FlushReports() {
          I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I)
     const_cast<BugType*>(*I)->FlushReports(*this);
 
+  // We need to flush reports in deterministic order to ensure the order
+  // of the reports is consistent between runs.
   typedef std::vector<BugReportEquivClass *> ContVecTy;
   for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end();
        EI != EE; ++EI){
diff --git a/clang/lib/StaticAnalyzer/Core/PathDiagnostic.cpp b/clang/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
index 394e975d4e7..b4c9068784f 100644
--- a/clang/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
+++ b/clang/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
@@ -148,23 +148,14 @@ void PathDiagnosticConsumer::HandlePathDiagnostic(PathDiagnostic *D) {
 
   if (PathDiagnostic *orig = Diags.FindNodeOrInsertPos(profile, InsertPos)) {
     // Keep the PathDiagnostic with the shorter path.
+    // Note, the enclosing rutine is called in deterministic order, so the
+    // results will be consistent between runs (no reason to break ties if the
+    // size is the same).
     const unsigned orig_size = orig->full_size();
     const unsigned new_size = D->full_size();
-    
-    if (orig_size <= new_size) {
-      bool shouldKeepOriginal = true;
-      if (orig_size == new_size) {
-        // Here we break ties in a fairly arbitrary, but deterministic, way.
-        llvm::FoldingSetNodeID fullProfile, fullProfileOrig;
-        D->FullProfile(fullProfile);
-        orig->FullProfile(fullProfileOrig);
-        if (fullProfile.ComputeHash() < fullProfileOrig.ComputeHash())
-          shouldKeepOriginal = false;
-      }
+    if (orig_size <= new_size)
+      return;
 
-      if (shouldKeepOriginal)
-        return;
-    }
     Diags.RemoveNode(orig);
     delete orig;
   }