[PATCH 07/11] Fix keep-going mode in ScopDetection

[Andreas Simbuerger]

After doing the top-down traversion in the ScopDetection (to find the
canonical Scops) we do not expand the regions that were valid and had
errors.
As soon as we enter the expansion phase we will get a non canonical
region and test the validity again. In this stage we do not check for
errors and will always succeed in keep-going mode. This will not
produce the same result as running without keep-going.
---
 lib/Analysis/ScopDetection.cpp | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/Analysis/ScopDetection.cpp b/lib/Analysis/ScopDetection.cpp
index 0907dd3..a15ca19 100644
--- a/lib/Analysis/ScopDetection.cpp
+++ b/lib/Analysis/ScopDetection.cpp
@@ -546,13 +546,17 @@ Region *ScopDetection::expandRegion(Region &R) {
   while (ExpandedRegion) {
     DetectionContext Context(*ExpandedRegion, *AA, false /* verifying */);
     DEBUG(dbgs() << "\t\tTrying " << ExpandedRegion->getNameStr() << "\n");
+    // Only expand when we did not collect errors.
 
     // Check the exit first (cheap)
-    if (isValidExit(Context)) {
+    if (isValidExit(Context) && !Context.Log.hasErrors()) {
       // If the exit is valid check all blocks
       //  - if true, a valid region was found => store it + keep expanding
       //  - if false, .tbd. => stop  (should this really end the loop?)
-      if (!allBlocksValid(Context))
+      if (!allBlocksValid(Context) || Context.Log.hasErrors())
+        break;
+
+      if (Context.Log.hasErrors())
         break;
 
       // Delete unnecessary regions (allocated by getExpandedRegion)
@@ -628,10 +632,6 @@ void ScopDetection::findScops(Region &R) {
   for (auto &SubRegion : R)
     findScops(*SubRegion);
 
-  // Do not expand when we had errors. Bad things may happen.
-  if (IsValidRegion && HasErrors)
-    return;
-
   // Try to expand regions.
   //
   // As the region tree normally only contains canonical regions, non canonical
@@ -644,6 +644,11 @@ void ScopDetection::findScops(Region &R) {
     ToExpand.push_back(SubRegion.get());
 
   for (Region *CurrentRegion : ToExpand) {
+    // Skip regions that had errors.
+    bool HadErrors = Logs.hasErrors(CurrentRegion);
+    if (HadErrors)
+      continue;
+
     // Skip invalid regions. Regions may become invalid, if they are element of
     // an already expanded region.
     if (ValidRegions.find(CurrentRegion) == ValidRegions.end())
-- 
2.0.0