[Coverage] Fix an issue where a coverage region might not be created for a macro containing a loop statement.

The issue happened when a macro contained a full for or
while statement, which body ended at the end of the macro.

Differential Revision: http://reviews.llvm.org/D19725

llvm-svn: 268511

1 files changed, 19 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 820ba1b8f72..d3fd19c1745 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -443,15 +443,31 @@ struct CounterCoverageMappingBuilder
     return ExitCount;
   }
 
+  /// \brief Check whether a region with bounds \c StartLoc and \c EndLoc
+  /// is already added to \c SourceRegions.
+  bool isRegionAlreadyAdded(SourceLocation StartLoc, SourceLocation EndLoc) {
+    return SourceRegions.rend() !=
+           std::find_if(SourceRegions.rbegin(), SourceRegions.rend(),
+                        [&](const SourceMappingRegion &Region) {
+                          return Region.getStartLoc() == StartLoc &&
+                                 Region.getEndLoc() == EndLoc;
+                        });
+  }
+
   /// \brief Adjust the most recently visited location to \c EndLoc.
   ///
   /// This should be used after visiting any statements in non-source order.
   void adjustForOutOfOrderTraversal(SourceLocation EndLoc) {
     MostRecentLocation = EndLoc;
-    // Avoid adding duplicate regions if we have a completed region on the top
-    // of the stack and are adjusting to the end of a virtual file.
+    // The code region for a whole macro is created in handleFileExit() when
+    // it detects exiting of the virtual file of that macro. If we visited
+    // statements in non-source order, we might already have such a region
+    // added, for example, if a body of a loop is divided among multiple
+    // macros. Avoid adding duplicate regions in such case.
     if (getRegion().hasEndLoc() &&
-        MostRecentLocation == getEndOfFileOrMacro(MostRecentLocation))
+        MostRecentLocation == getEndOfFileOrMacro(MostRecentLocation) &&
+        isRegionAlreadyAdded(getStartOfFileOrMacro(MostRecentLocation),
+                             MostRecentLocation))
       MostRecentLocation = getIncludeOrExpansionLoc(MostRecentLocation);
   }